This paper elaborates the hydraulic characteristics of the water supply network of the town of Puerto Ayora. First, it intends to replicate the household individual storage by simulating nodal tanks with the use of the EPANET software. Later, it uses the Pressure-Driven Approach (PDA) to develop a methodology that estimates the overflow of storage facilities, one of the main sources of wastage in Puerto Ayora. Finally, it uses the Demand-Driven Approach (DDA), with the aim of assessing the network in the future, under four population growth scenarios. With the chosen moderate growth scenario, two options are suggested in order to tackle the water supply issues at the end of the planning horizon.
Analysis and Characterization of Kainji Reservoir Inflow System_ Crimson Publ...CrimsonpublishersEAES
This study characterized the Kainji reservoir system in Nigeria by calculating the resilience index (m) using inflow data from 1990-2014. Different demand levels from 0 to 0.8 were used to calculate m based on the coefficient of variation and Vogel-Stedinger relationship. The results showed that m was above 1 for all demand levels except 0.8, indicating the reservoir behaves as a within year system with quick refill times. Higher demand levels decreased reservoir resilience. Therefore, the Kainji reservoir was characterized as a reliable within year system for hydropower generation.
Determination of design discharge and environmental flow in micro-hydropower ...Daniel Ngoma
In designing micro hydropower plants capacity, the amount of water flow discharge determination is very essential in estimating the power output for the micro hydropower scheme due to the fact that in recent years there has been an increase in water demand due irrigation activities because of an increase in agriculture activities [1]. From the literature, there are several methods that are used to determine hydro turbine water flow discharge but the most widely used method is the hydrological method which is based on the formulation of flow duration curve or hydrograph for the respective river flow based on site historical and measured hydrological data.
The hydrograph represents the amount of water flow in m3/s that is available for a particular river or stream in percentage from the historical hydrological data which has been computed over a period of more than one year. From the study of Hhaynu River which is a small river in Tanzania, the computed flow results show that, 8% of the time the flow is at 2.3 m3/s while at 50% of the time the river flow was at 1.86 m3/s and at 100% of the time the water flow was at 0.60 m3/s. When determining design discharge for run-of-river schemes, provision have to be considered for environmental flow on which for the Hhaynu River this has been analysed to be 0.2 m3/s (33.3% of river base flow) which resulted to the hydro-turbine development design water flow discharge of 0.4 m3/s from the computed flow duration curve with provision for environmental flow.
The usefulness of developing flow duration curve for rivers is to determine the available water flow in a particular small river and its suitability for micro hydropower development from estimates of the amount of water flow discharge.
An Effective Tool for Drinking Water ProtectionEsri
The document discusses ICWater, a tool developed by Leidos to predict the spread and impact of hazardous material releases in river systems. ICWater forecasts (1) where contaminants will travel, (2) if they will reach drinking water intakes, (3) when they will arrive, and (4) if concentrations will threaten human health. It interfaces with USGS stream gauges and databases on infrastructure to provide timely information to decision makers. ICWater successfully modeled the 2014 Elk River chemical spill in West Virginia to advise authorities and protect drinking water.
This document evaluates how changes in surface water reservoir storage affect power generation operations in Texas. It uses a river basin model and five cases: 1) 10% decrease in existing reservoir storage, 2) 50% decrease, 3) elimination of storage, 4) 10% increase in storage, and 5) construction of new reservoirs increasing storage by 9%. The Brazos River basin is analyzed to quantify reliability, resiliency, and vulnerability of power plants under different storage scenarios. Reliability generally decreases as storage decreases, while resiliency and vulnerability remain constant. Metrics are relatively constant with increased storage, except for one plant. Changing reservoir storage impacts other basin water users - decreasing storage benefits others, while increasing storage harms many users
Hydrological Calibration in the Mount Lofty Ranges using Source Paramenter Es...eWater
This document describes the calibration of a hydrological model of the Mount Lofty Ranges in South Australia using the Parameter ESTimation (PEST) tool. The model was updated with new streamflow data and calibrated using PEST to improve upon a previous calibration that used the Rainfall Runoff Library. PEST optimized hydrological parameters to minimize differences between observed and modeled monthly and daily streamflow and flow durations. The PEST calibration resulted in improved matches to observed streamflow compared to the previous calibration.
This document provides information on hydrological surveys for micro-hydro power projects. It discusses key concepts like plant factor, load factor, and hydrographs. Methods are presented for analyzing annual average daily flow, flow duration curves, and matching power supply and demand. The importance of capability and demand surveys is explained to assess local management ability and potential energy needs. Overall, the document outlines the essential hydrological concepts and analysis methods needed to properly assess the viability and design of a micro-hydro project.
DEVELOPMENT OF CLEAN WATER DISTRIBUTION NETWORK CAPACITY BY USING WATERCADIAEME Publication
This document describes a study that used WaterCAD software to analyze and develop the clean water distribution network for Kedungkandang District in Malang, Indonesia. The study projected the population to reach 27,284 people by 2031. It determined the average daily clean water need would be 41,763 liters/second and peak hour need would be 65,150 liters/second. Hydraulic simulations found the water pressure would be between 1.6-2.3 atmospheres and velocities between 0.47-1.85 meters/second, meeting design criteria. The study concluded the existing network was sufficient with some pipe diameter changes required for development.
Approaches for obtaining design flood peak discharges in sarada riverIAEME Publication
1. The document analyzes flood frequency in the Sarada River in India using peak discharge data from 2000-2013.
2. It finds that the Weibull 3 distribution best theoretically represents the data and the Gamma 3 distribution best empirically represents the data based on probability and quantile graphs.
3. The analysis concludes that the maximum recorded discharge of 2548.07 m3/s in 2012 can be used for flood protection and infrastructure design with a 2-year recurrence interval.
Analysis and Characterization of Kainji Reservoir Inflow System_ Crimson Publ...CrimsonpublishersEAES
This study characterized the Kainji reservoir system in Nigeria by calculating the resilience index (m) using inflow data from 1990-2014. Different demand levels from 0 to 0.8 were used to calculate m based on the coefficient of variation and Vogel-Stedinger relationship. The results showed that m was above 1 for all demand levels except 0.8, indicating the reservoir behaves as a within year system with quick refill times. Higher demand levels decreased reservoir resilience. Therefore, the Kainji reservoir was characterized as a reliable within year system for hydropower generation.
Determination of design discharge and environmental flow in micro-hydropower ...Daniel Ngoma
In designing micro hydropower plants capacity, the amount of water flow discharge determination is very essential in estimating the power output for the micro hydropower scheme due to the fact that in recent years there has been an increase in water demand due irrigation activities because of an increase in agriculture activities [1]. From the literature, there are several methods that are used to determine hydro turbine water flow discharge but the most widely used method is the hydrological method which is based on the formulation of flow duration curve or hydrograph for the respective river flow based on site historical and measured hydrological data.
The hydrograph represents the amount of water flow in m3/s that is available for a particular river or stream in percentage from the historical hydrological data which has been computed over a period of more than one year. From the study of Hhaynu River which is a small river in Tanzania, the computed flow results show that, 8% of the time the flow is at 2.3 m3/s while at 50% of the time the river flow was at 1.86 m3/s and at 100% of the time the water flow was at 0.60 m3/s. When determining design discharge for run-of-river schemes, provision have to be considered for environmental flow on which for the Hhaynu River this has been analysed to be 0.2 m3/s (33.3% of river base flow) which resulted to the hydro-turbine development design water flow discharge of 0.4 m3/s from the computed flow duration curve with provision for environmental flow.
The usefulness of developing flow duration curve for rivers is to determine the available water flow in a particular small river and its suitability for micro hydropower development from estimates of the amount of water flow discharge.
An Effective Tool for Drinking Water ProtectionEsri
The document discusses ICWater, a tool developed by Leidos to predict the spread and impact of hazardous material releases in river systems. ICWater forecasts (1) where contaminants will travel, (2) if they will reach drinking water intakes, (3) when they will arrive, and (4) if concentrations will threaten human health. It interfaces with USGS stream gauges and databases on infrastructure to provide timely information to decision makers. ICWater successfully modeled the 2014 Elk River chemical spill in West Virginia to advise authorities and protect drinking water.
This document evaluates how changes in surface water reservoir storage affect power generation operations in Texas. It uses a river basin model and five cases: 1) 10% decrease in existing reservoir storage, 2) 50% decrease, 3) elimination of storage, 4) 10% increase in storage, and 5) construction of new reservoirs increasing storage by 9%. The Brazos River basin is analyzed to quantify reliability, resiliency, and vulnerability of power plants under different storage scenarios. Reliability generally decreases as storage decreases, while resiliency and vulnerability remain constant. Metrics are relatively constant with increased storage, except for one plant. Changing reservoir storage impacts other basin water users - decreasing storage benefits others, while increasing storage harms many users
Hydrological Calibration in the Mount Lofty Ranges using Source Paramenter Es...eWater
This document describes the calibration of a hydrological model of the Mount Lofty Ranges in South Australia using the Parameter ESTimation (PEST) tool. The model was updated with new streamflow data and calibrated using PEST to improve upon a previous calibration that used the Rainfall Runoff Library. PEST optimized hydrological parameters to minimize differences between observed and modeled monthly and daily streamflow and flow durations. The PEST calibration resulted in improved matches to observed streamflow compared to the previous calibration.
This document provides information on hydrological surveys for micro-hydro power projects. It discusses key concepts like plant factor, load factor, and hydrographs. Methods are presented for analyzing annual average daily flow, flow duration curves, and matching power supply and demand. The importance of capability and demand surveys is explained to assess local management ability and potential energy needs. Overall, the document outlines the essential hydrological concepts and analysis methods needed to properly assess the viability and design of a micro-hydro project.
DEVELOPMENT OF CLEAN WATER DISTRIBUTION NETWORK CAPACITY BY USING WATERCADIAEME Publication
This document describes a study that used WaterCAD software to analyze and develop the clean water distribution network for Kedungkandang District in Malang, Indonesia. The study projected the population to reach 27,284 people by 2031. It determined the average daily clean water need would be 41,763 liters/second and peak hour need would be 65,150 liters/second. Hydraulic simulations found the water pressure would be between 1.6-2.3 atmospheres and velocities between 0.47-1.85 meters/second, meeting design criteria. The study concluded the existing network was sufficient with some pipe diameter changes required for development.
Approaches for obtaining design flood peak discharges in sarada riverIAEME Publication
1. The document analyzes flood frequency in the Sarada River in India using peak discharge data from 2000-2013.
2. It finds that the Weibull 3 distribution best theoretically represents the data and the Gamma 3 distribution best empirically represents the data based on probability and quantile graphs.
3. The analysis concludes that the maximum recorded discharge of 2548.07 m3/s in 2012 can be used for flood protection and infrastructure design with a 2-year recurrence interval.
1) The study investigated fluid dynamics of a ventricular assist device (VAD) called the Spiral Vortex (SV) VAD using laser Doppler anemometry while pumping a blood analogue fluid under physiological conditions.
2) The flow was dominated by an irrotational vortex that accelerated and precessed in phase with the pumping diaphragm, and two unexpected structures enhanced wall washing.
3) Under a weaning mode, the main vortex coherence degraded and recirculation was observed, indicating a need for anticoagulation in this mode. Turbulence increased with asymmetric diaphragm buckling in both modes.
WATER RESOURCE SUSTAINABILITY OF THE PALOUSE REGION: A SYSTEMS APPROACHRamesh Dhungel
This thesis examines the sustainability of water resources in the Palouse Region located on the border of Idaho and Washington. The region relies on two confined groundwater aquifers, the upper Wanapum and lower Grande Ronde, which show declining water levels. The author develops system dynamics models to simulate population growth, water demand, hydrological processes, and economic factors. The simple model lumps the aquifers together, while the hydraulically separated model divides them based on geology. Water balance calculations estimate recharge rates. Regression analysis determines the price elasticity of water demand. The models project the lifespan of the aquifers under different recharge and demand scenarios. Assuming potential surface water use and a water management strategy,
A new methodology is developed to analyse existing water quality monitoring networks. This methodology
incorporates different aspects of monitoring, including vulnerability/probability assessment, environmental
health risk, the value of information, and redundancy reduction. The work starts with a formulation of a
conceptual framework for groundwater quality monitoring to represent the methodology’s context. This
work presents the development of Bayesian techniques for the assessment of groundwater quality. The
primary aim is to develop a predictive model and a computer system to assess and predict the impact of
pollutants on the water column. The process of the analysis begins by postulating a model in light of all
available knowledge taken from relevant phenomenon. The previous knowledge as represented by the prior
distribution of the model parameters is then combined with the new data through Bayes’ theorem to yield
the current knowledge represented by the posterior distribution of model parameters. This process of
updating information about the unknown model parameters is then repeated in a sequential manner as
more and more new information becomes available.
This document describes a computer software developed to determine pump capacity and storage tank size for public water distribution schemes. The software takes inputs like population, housing units, tower height, and pipe characteristics. It then calculates storage tank size based on population water needs and selects a suitable tank from manufacturer specifications. Pump capacity is estimated considering flow rate needed to fill the tank and total dynamic and static heads in the system. The software was tested on a case study community and produced results closely matching manual calculations. The software can help accurately size tanks and select pumps for water projects based on site details.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes the development of an integrated Riverine Environmental Flow Decision Support System (REFDSS) to evaluate the ecological effects of alternative flow scenarios on river ecosystems. Key points:
- The REFDSS was developed for the Upper Delaware River as a user-friendly tool to enable evaluation and comparison of potential habitat availability under different flow management scenarios.
- It incorporates hydrodynamic modeling of habitat variables, hydrological modeling of reservoir release scenarios, and habitat suitability criteria for various species to calculate potential available habitat.
- The REFDSS allows modification of habitat suitability criteria and addition of new flow scenarios to compare effects on fish and mussel habitat and facilitate environmental flow management decisions.
Rebuilding a Resilient New Jersey Shore was a presentation given on December 7, 2012 at Monmouth University by Charles B. Chestnutt, a coastal engineer with the Institute for Water Resources of the U.S. Army Corps of Engineers based in Alexandria, Virginia.
Geohydraulic parameters are essential elements in groundwater resource management and conservation.
Most of these parameters especially the hydraulic conductivity and transmissivity are usually estimated
from pumping test carried out on drilled boreholes. This paper presents a study conducted in Abi area of
the Ikom-Mamfe Embayment with the objective of estimating aquifer parameters from 30 evenly
distributed vertical electrical soundings using the Schlumberger configuration and hydrogeologic
measurements from 28 boreholes within the area as an alternative way of generating an initial data
for groundwater characterisation and quality assessment in the area. The results showed low resistivity
645 Xm, hydraulic conductivity 62.0 105 m/s (61.7 m/day) and transmissivity 65.2 104 m2/s
(645 m2/day) for the water-bearing aquifer horizons in the northeastern and northwestern parts of
the study area due to the nature of the aquifer system that were predominantly fractured shale. The sand
based aquifers had higher values in the neighbourhood of 100–800 Xm, 4.0 105–1.0 104 m/s
(3.46–9.04 m/day) and 6.94 104–3.81 103 m2/s (60–330 m2/day) for the respective parameters
mentioned above. The potability of the groundwater system as observed from hydrogeologic measurements
of water samples from most boreholes were relatively poor, having electrical conductivity
and total dissolved solids values of 250–931.0 lS/cm and 500–623.77 mg/l respectively due to the
influence of clay minerals within the aquifer horizon. Some of the vertical electrical sounding points were
taken in the vicinity were pumping tests and lithologic data were available for adequate comparison of
the results.Electrical resistivity
Geohydraulic parameters
Groundwater
Hydraulic conductivity
Ikom-Mamfe Embayment
Abi-Nigeria
This document discusses statistical analysis to identify the main parameters affecting wastewater quality index (WWQI) at sewage treatment plants and to predict biochemical oxygen demand (BOD). It presents a fuzzy multi-criteria decision making model to calculate WWQI based on eight wastewater parameters. Correlation analysis identified parameters like total dissolved solids, BOD, chemical oxygen demand as significantly correlated with WWQI. Regression analysis developed an equation to estimate WWQI and BOD from dissolved oxygen measurements. The study shows WWQI is influenced most by BOD, COD, suspended solids and total dissolved solids.
This document summarizes a vulnerability analysis of sub-basins in Massachusetts to determine which are most likely to experience water stress under new regulations. The analysis scored sub-basins based on 7 factors like population change, groundwater permits, and surface water resources. It found the eastern and southwest parts of the state most vulnerable due to high population growth. Over 76% of the state's area had medium vulnerability. The analysis can help identify which sub-basins may need to implement strategies to minimize water use under the new Water Management Act.
ASR in Texas: Open for "Bidness", Brian Sledge and Charles MaguireTWCA
This document summarizes recent legislation and rules in Texas regarding aquifer storage and recovery (ASR) projects. The key points are:
1) House Bill 655 and rules by the Texas Commission on Environmental Quality (TCEQ) in 2016 have expedited the ASR permitting process, allowing different types of authorizations and clarifying notice requirements.
2) The new rules require compliance with federal drinking water standards but no stricter requirements, and they establish testing, metering and reporting standards for ASR projects.
3) There are still many uncertainties that are not expressly addressed, including liability, protecting groundwater plumes, and regulation of different water sources. Applicants must demonstrate the requirements themselves
The document discusses hydrological concepts including flow duration curves, meteorological stations, indices used to analyze streamflow, weirs, and the relationship between upstream and downstream areas. It provides definitions and examples of flow duration curves, exceedance probability, flashiness, and how afforestation and cultivation can impact the hydrological response of different biomes. Graphs and diagrams are included to illustrate hydrological responses, streamflow variability, and the impact of land use changes.
Water Management Strategies Using Multi-Criteria Decision Analysis in Santa C...Scientific Review SR
Islands threatened by tourism around the world are under significant stress due to overutilization of (scarce) water resources. The continuous increase of water demand in Puerto Ayora, the main touristic centre of the Galápagos, has become a threat for the water supply system, portraying the current situation unsustainable on the long-term horizon. For this reason, a Multi-Criteria Decision Analysis (MCDA) is tested as a suitable methodology in the presence of scarce data, leading to a set of indicators and intervention strategies, aiming to mitigate the future water demand coverage. The current analysis revealed the most sustainable solution, including environmental, technical, economic and social criteria, by using the DEFINITE software. The results indicate that best option for most of the stakeholders’ groups is the option combining all proposed-sustainable options like greywater recycling, specific demand reduction and rainwater harvesting.
This document summarizes a study that used multivariate statistical analysis to assess water quality in the Chamera-I reservoir in India over a two-year period from 2010-2012. Water quality parameters were measured seasonally and subjected to cluster analysis, principal component analysis, and correlation and regression analysis. Cluster analysis identified two major clusters separating the rainy season from the other three seasons. Principal component analysis selected three variables accounting for 100% of the total variance in water quality over time. Correlation analysis identified significant linear relationships between various water quality parameters.
Alaska; Optimal Storage Volumes For Rainwater Catchment Systems In Alaska D7Z
This document presents research on optimal storage volumes for rainwater catchment systems in Alaska. The researchers modeled systems in 12 Alaskan communities factoring in water usage, roof catchment area, climate and temperature thresholds. They found that storage needs varied significantly based on these location-specific characteristics. Optimal storage was defined as the minimum tank volume needed to meet water demands during the operational season while maintaining at least a 5% reserve. The results provide guidelines to help design effective rainwater catchment systems tailored to local conditions in Alaska.
The document describes calibrating and validating the parameters of the HEC-HMS hydrological model for the Kharkai River Basin in eastern India. The objectives are to calibrate parameters like initial loss, constant rate, impervious area, lag time and peaking coefficient that affect rainfall-runoff processes. The validated model is used to compute flood peaks and times to peak from rainfall events. Model performance is evaluated using statistical measures for the study area. Calibration results show the model can accurately predict peak flood volumes and times to peak, indicating HEC-HMS is suitable for modeling the Kharkai catchment.
flow_through_linear_weir in analysis of the huamrajak
1) The document discusses a numerical study using computational fluid dynamics (CFD) to simulate flow over a linear weir.
2) The CFD simulation results for head-discharge relationships and flow patterns are compared to experimental data from literature and show close agreement.
3) The maximum error between the CFD and experimental results for discharge is within 3% indicating CFD can accurately predict flows over hydraulic structures like weirs.
SIMULATION OF PRESSURE VARIATIONS WITHIN KIMILILI WATER SUPPLY SYSTEM USING E...IAEME Publication
Water Supply system is a system of engineered hydrologic and hydraulic components which provide water supply for domestic use, industrial purposes, fire fighting and so on. The system
comprises of intake structures, treatment units, storage tanks and distribution systems. A well designed water supply system is meant to operate optimally such that consumers have access to portable water of sufficient pressure and quality at all times. However during operations of water supply systems, cases of pressure drops, Leakages and contamination occur and the main challenge is the lack of a simple tool to accurately predict zones of low pressures and areas where quality is compromised.
Use of Storage Water in a Hydroelectric SystemIOSR Journals
This document discusses the use of storage water in hydroelectric systems. It begins by discussing how hydroelectric systems work and the importance of water storage. It then reviews several past studies that have analyzed optimal water storage and use in hydroelectric systems. These studies used different assumptions and approaches, such as using decision support systems and dynamic programming. The document proposes using an existing decision support system to optimize water use during low flow periods. It describes the components and benefits of comprehensive decision support systems for hydroelectric operations and planning. Finally, it concludes that decision support systems can optimize water storage and use in hydroelectric systems based on updated forecasts and probabilistic modeling.
Even Flow - Water coordination efficiency & Hydropower-1Johan Gustavsson
Johan Gustavsson wrote a master's thesis examining the impact of the EU Water Framework Directive on water coordination efficiency in hydropower markets. The thesis implements a dynamic market model to compare Stackelberg competition and monopoly/collusion market types under different reservoir capacities and an outflow regulation. The main finding is that under limited storage, a lack of centralized coordination causes competition to be less desirable than monopoly from a welfare perspective. However, with sufficient reservoir capacity, the benefits of competition outweigh this coordination cost.
1) The study investigated fluid dynamics of a ventricular assist device (VAD) called the Spiral Vortex (SV) VAD using laser Doppler anemometry while pumping a blood analogue fluid under physiological conditions.
2) The flow was dominated by an irrotational vortex that accelerated and precessed in phase with the pumping diaphragm, and two unexpected structures enhanced wall washing.
3) Under a weaning mode, the main vortex coherence degraded and recirculation was observed, indicating a need for anticoagulation in this mode. Turbulence increased with asymmetric diaphragm buckling in both modes.
WATER RESOURCE SUSTAINABILITY OF THE PALOUSE REGION: A SYSTEMS APPROACHRamesh Dhungel
This thesis examines the sustainability of water resources in the Palouse Region located on the border of Idaho and Washington. The region relies on two confined groundwater aquifers, the upper Wanapum and lower Grande Ronde, which show declining water levels. The author develops system dynamics models to simulate population growth, water demand, hydrological processes, and economic factors. The simple model lumps the aquifers together, while the hydraulically separated model divides them based on geology. Water balance calculations estimate recharge rates. Regression analysis determines the price elasticity of water demand. The models project the lifespan of the aquifers under different recharge and demand scenarios. Assuming potential surface water use and a water management strategy,
A new methodology is developed to analyse existing water quality monitoring networks. This methodology
incorporates different aspects of monitoring, including vulnerability/probability assessment, environmental
health risk, the value of information, and redundancy reduction. The work starts with a formulation of a
conceptual framework for groundwater quality monitoring to represent the methodology’s context. This
work presents the development of Bayesian techniques for the assessment of groundwater quality. The
primary aim is to develop a predictive model and a computer system to assess and predict the impact of
pollutants on the water column. The process of the analysis begins by postulating a model in light of all
available knowledge taken from relevant phenomenon. The previous knowledge as represented by the prior
distribution of the model parameters is then combined with the new data through Bayes’ theorem to yield
the current knowledge represented by the posterior distribution of model parameters. This process of
updating information about the unknown model parameters is then repeated in a sequential manner as
more and more new information becomes available.
This document describes a computer software developed to determine pump capacity and storage tank size for public water distribution schemes. The software takes inputs like population, housing units, tower height, and pipe characteristics. It then calculates storage tank size based on population water needs and selects a suitable tank from manufacturer specifications. Pump capacity is estimated considering flow rate needed to fill the tank and total dynamic and static heads in the system. The software was tested on a case study community and produced results closely matching manual calculations. The software can help accurately size tanks and select pumps for water projects based on site details.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes the development of an integrated Riverine Environmental Flow Decision Support System (REFDSS) to evaluate the ecological effects of alternative flow scenarios on river ecosystems. Key points:
- The REFDSS was developed for the Upper Delaware River as a user-friendly tool to enable evaluation and comparison of potential habitat availability under different flow management scenarios.
- It incorporates hydrodynamic modeling of habitat variables, hydrological modeling of reservoir release scenarios, and habitat suitability criteria for various species to calculate potential available habitat.
- The REFDSS allows modification of habitat suitability criteria and addition of new flow scenarios to compare effects on fish and mussel habitat and facilitate environmental flow management decisions.
Rebuilding a Resilient New Jersey Shore was a presentation given on December 7, 2012 at Monmouth University by Charles B. Chestnutt, a coastal engineer with the Institute for Water Resources of the U.S. Army Corps of Engineers based in Alexandria, Virginia.
Geohydraulic parameters are essential elements in groundwater resource management and conservation.
Most of these parameters especially the hydraulic conductivity and transmissivity are usually estimated
from pumping test carried out on drilled boreholes. This paper presents a study conducted in Abi area of
the Ikom-Mamfe Embayment with the objective of estimating aquifer parameters from 30 evenly
distributed vertical electrical soundings using the Schlumberger configuration and hydrogeologic
measurements from 28 boreholes within the area as an alternative way of generating an initial data
for groundwater characterisation and quality assessment in the area. The results showed low resistivity
645 Xm, hydraulic conductivity 62.0 105 m/s (61.7 m/day) and transmissivity 65.2 104 m2/s
(645 m2/day) for the water-bearing aquifer horizons in the northeastern and northwestern parts of
the study area due to the nature of the aquifer system that were predominantly fractured shale. The sand
based aquifers had higher values in the neighbourhood of 100–800 Xm, 4.0 105–1.0 104 m/s
(3.46–9.04 m/day) and 6.94 104–3.81 103 m2/s (60–330 m2/day) for the respective parameters
mentioned above. The potability of the groundwater system as observed from hydrogeologic measurements
of water samples from most boreholes were relatively poor, having electrical conductivity
and total dissolved solids values of 250–931.0 lS/cm and 500–623.77 mg/l respectively due to the
influence of clay minerals within the aquifer horizon. Some of the vertical electrical sounding points were
taken in the vicinity were pumping tests and lithologic data were available for adequate comparison of
the results.Electrical resistivity
Geohydraulic parameters
Groundwater
Hydraulic conductivity
Ikom-Mamfe Embayment
Abi-Nigeria
This document discusses statistical analysis to identify the main parameters affecting wastewater quality index (WWQI) at sewage treatment plants and to predict biochemical oxygen demand (BOD). It presents a fuzzy multi-criteria decision making model to calculate WWQI based on eight wastewater parameters. Correlation analysis identified parameters like total dissolved solids, BOD, chemical oxygen demand as significantly correlated with WWQI. Regression analysis developed an equation to estimate WWQI and BOD from dissolved oxygen measurements. The study shows WWQI is influenced most by BOD, COD, suspended solids and total dissolved solids.
This document summarizes a vulnerability analysis of sub-basins in Massachusetts to determine which are most likely to experience water stress under new regulations. The analysis scored sub-basins based on 7 factors like population change, groundwater permits, and surface water resources. It found the eastern and southwest parts of the state most vulnerable due to high population growth. Over 76% of the state's area had medium vulnerability. The analysis can help identify which sub-basins may need to implement strategies to minimize water use under the new Water Management Act.
ASR in Texas: Open for "Bidness", Brian Sledge and Charles MaguireTWCA
This document summarizes recent legislation and rules in Texas regarding aquifer storage and recovery (ASR) projects. The key points are:
1) House Bill 655 and rules by the Texas Commission on Environmental Quality (TCEQ) in 2016 have expedited the ASR permitting process, allowing different types of authorizations and clarifying notice requirements.
2) The new rules require compliance with federal drinking water standards but no stricter requirements, and they establish testing, metering and reporting standards for ASR projects.
3) There are still many uncertainties that are not expressly addressed, including liability, protecting groundwater plumes, and regulation of different water sources. Applicants must demonstrate the requirements themselves
The document discusses hydrological concepts including flow duration curves, meteorological stations, indices used to analyze streamflow, weirs, and the relationship between upstream and downstream areas. It provides definitions and examples of flow duration curves, exceedance probability, flashiness, and how afforestation and cultivation can impact the hydrological response of different biomes. Graphs and diagrams are included to illustrate hydrological responses, streamflow variability, and the impact of land use changes.
Water Management Strategies Using Multi-Criteria Decision Analysis in Santa C...Scientific Review SR
Islands threatened by tourism around the world are under significant stress due to overutilization of (scarce) water resources. The continuous increase of water demand in Puerto Ayora, the main touristic centre of the Galápagos, has become a threat for the water supply system, portraying the current situation unsustainable on the long-term horizon. For this reason, a Multi-Criteria Decision Analysis (MCDA) is tested as a suitable methodology in the presence of scarce data, leading to a set of indicators and intervention strategies, aiming to mitigate the future water demand coverage. The current analysis revealed the most sustainable solution, including environmental, technical, economic and social criteria, by using the DEFINITE software. The results indicate that best option for most of the stakeholders’ groups is the option combining all proposed-sustainable options like greywater recycling, specific demand reduction and rainwater harvesting.
This document summarizes a study that used multivariate statistical analysis to assess water quality in the Chamera-I reservoir in India over a two-year period from 2010-2012. Water quality parameters were measured seasonally and subjected to cluster analysis, principal component analysis, and correlation and regression analysis. Cluster analysis identified two major clusters separating the rainy season from the other three seasons. Principal component analysis selected three variables accounting for 100% of the total variance in water quality over time. Correlation analysis identified significant linear relationships between various water quality parameters.
Alaska; Optimal Storage Volumes For Rainwater Catchment Systems In Alaska D7Z
This document presents research on optimal storage volumes for rainwater catchment systems in Alaska. The researchers modeled systems in 12 Alaskan communities factoring in water usage, roof catchment area, climate and temperature thresholds. They found that storage needs varied significantly based on these location-specific characteristics. Optimal storage was defined as the minimum tank volume needed to meet water demands during the operational season while maintaining at least a 5% reserve. The results provide guidelines to help design effective rainwater catchment systems tailored to local conditions in Alaska.
The document describes calibrating and validating the parameters of the HEC-HMS hydrological model for the Kharkai River Basin in eastern India. The objectives are to calibrate parameters like initial loss, constant rate, impervious area, lag time and peaking coefficient that affect rainfall-runoff processes. The validated model is used to compute flood peaks and times to peak from rainfall events. Model performance is evaluated using statistical measures for the study area. Calibration results show the model can accurately predict peak flood volumes and times to peak, indicating HEC-HMS is suitable for modeling the Kharkai catchment.
flow_through_linear_weir in analysis of the huamrajak
1) The document discusses a numerical study using computational fluid dynamics (CFD) to simulate flow over a linear weir.
2) The CFD simulation results for head-discharge relationships and flow patterns are compared to experimental data from literature and show close agreement.
3) The maximum error between the CFD and experimental results for discharge is within 3% indicating CFD can accurately predict flows over hydraulic structures like weirs.
SIMULATION OF PRESSURE VARIATIONS WITHIN KIMILILI WATER SUPPLY SYSTEM USING E...IAEME Publication
Water Supply system is a system of engineered hydrologic and hydraulic components which provide water supply for domestic use, industrial purposes, fire fighting and so on. The system
comprises of intake structures, treatment units, storage tanks and distribution systems. A well designed water supply system is meant to operate optimally such that consumers have access to portable water of sufficient pressure and quality at all times. However during operations of water supply systems, cases of pressure drops, Leakages and contamination occur and the main challenge is the lack of a simple tool to accurately predict zones of low pressures and areas where quality is compromised.
Use of Storage Water in a Hydroelectric SystemIOSR Journals
This document discusses the use of storage water in hydroelectric systems. It begins by discussing how hydroelectric systems work and the importance of water storage. It then reviews several past studies that have analyzed optimal water storage and use in hydroelectric systems. These studies used different assumptions and approaches, such as using decision support systems and dynamic programming. The document proposes using an existing decision support system to optimize water use during low flow periods. It describes the components and benefits of comprehensive decision support systems for hydroelectric operations and planning. Finally, it concludes that decision support systems can optimize water storage and use in hydroelectric systems based on updated forecasts and probabilistic modeling.
Even Flow - Water coordination efficiency & Hydropower-1Johan Gustavsson
Johan Gustavsson wrote a master's thesis examining the impact of the EU Water Framework Directive on water coordination efficiency in hydropower markets. The thesis implements a dynamic market model to compare Stackelberg competition and monopoly/collusion market types under different reservoir capacities and an outflow regulation. The main finding is that under limited storage, a lack of centralized coordination causes competition to be less desirable than monopoly from a welfare perspective. However, with sufficient reservoir capacity, the benefits of competition outweigh this coordination cost.
Putting into consideration most of the dynamics of Water production costs, the SD approach is used in determining the Unit cost of water production. It is hoped that the model will assist Water Companies, Water Supply Agencies and Board to price water in an economic manner.
Analysis of Water Quality Characteristics in Distribution NetworksAI Publications
In this study, a model was developed by Epanet2.0 software to analyze water quality for parameters of hydraulic and water quality model (chlorine concentration and water age model) for a segment of Erbil city WDS by using observed and documented data. Controlling free residual chlorine properly is important to ensure meeting regulatory requirements and satisfying customer needs. For the calibration process and collecting field data digital pressure loggers for recording pressure in a WDS was installed. For discharge measurements, ultrasonic flow meters were used. To assure the reliability of the model a calibration process was carried out for extended period analysis and several alternatives had been studied as a solution to overcome negative pressure zones by the calculated Hazen William C-factor. This kind of study can be used to predict so many infrastructure projects.
This document describes a procedure for developing a conceptual model of a river system for flood control purposes using a case study of the Demer River in Belgium. Key points:
- A conceptual model was developed based on simulations from a detailed full hydrodynamic model to reduce computation time for real-time flood control applications.
- The conceptual model was developed through identifying representative discharges, storage points, and hydraulic structures from the river network and calibrating it using a limited number of full model simulations.
- The performance of the conceptual model was evaluated against historical flood events and showed close agreement with the full model, enabling its use for real-time flood control applications requiring many model iterations.
EXPLORING OPTIONS IN THE DESIGN OF A WATER DISTRIBUTION NETWORK FOR FIREFIGHTINGIAEME Publication
Exploring options in the design of a water distribution network for fire-fighting is presented. The method used was that of the gradient method embedded in the EPANET software. Analysis were carried out for a typical residential estate in Ebocha village. Input data such as fire water demand, pipe lengths, pipe diameters and assumed pump sizes were fed into the EPANET software. Results showed that the existing water distribution network for firefighting was inefficient with a negative pressure of -116.89 metre head when water was released for the purpose of fire-fighting. A total of 5 cases and 25 options of simulations were carried out for the proposed network for the residential area.
Assessing the importance of geo hydrological data acquisition in the developm...Alexander Decker
The document discusses two groundwater flow models developed for Lagos, Nigeria and Birmingham, UK. The Birmingham model had extensive geo-hydrological data including geology, groundwater levels, recharge rates, abstraction data, and aquifer parameters obtained from field tests. This allowed for detailed discretization, calibration, and reliable predictive capabilities. The Lagos model had limited data, requiring interpolation and extrapolation. It had coarse discretization and assumed parameters. This greatly limited its reliability and predictive ability. The document recommends improving Nigeria's geo-hydrological data acquisition and accessibility to enable more effective water resources management planning and modeling.
Developing best practice for infilling daily river flow datahydrologywebsite1
This document evaluates techniques for infilling missing daily river flow data. It assesses 10 techniques using data from 25 UK river gauging stations with missing values. The techniques include regression, scaling, and equipercentile methods. Results show that the equipercentile and multiple regression approaches performed best overall based on Nash-Sutcliffe Model Efficiency and percent bias statistics. Case studies provide further insight and an example infilling is presented. The results demonstrate the potential for developing standardized infilling methodologies to improve data completeness.
A study confined to the lower tapi basin in Gujarat, India to find out the primary causes for 2006 floods in Surat city. The study involves collection of topographical data from the local geological survey organization, rainfall data from meteorological department of india and the application of HEC-HMS software from US Army corps of engineers to identify the primary cause of the runoff.
Smart metering technologies allow for gathering high resolution water demand data in the residential sector, opening up new opportunities for the development of models describing water consumers’ behaviors. Yet, gathering such accurate water demand data at the end-use level is limited by metering intrusiveness, costs, and privacy issues. In this paper, we contribute a stochastic simulation model for synthetically generating high-resolution time series of water use at the end-use level. Each water end-use fixture in our model is characterized by its signature (i.e., its typical single-use pattern), as well as frequency distributions of its number of uses per day, single use duration, time of use during the day, and contribution to the total household water demand. The model relies on statistical data from a real-world metering campaign across 9 cities in the US. Showcasing our model outputs, we demonstrate the potential usability of this model for characterizing the water end-use demands of different communities, as well as for analyzing the major components of peak demand and performing scenario analysis.
Developing a stochastic simulation model for the generation of residential wa...SmartH2O
This document reviews literature on using smart water meters to model and manage residential water demand. It discusses how smart meter data collected at high temporal and spatial resolution has advanced the ability to characterize, model, and design water conservation strategies. However, research thus far has focused on these aspects separately without much integration. The review provides a framework to classify water demand modeling studies and identifies trends and future challenges, such as supporting more integrated modeling and management approaches to address growing populations, limited water resources, and climate change impacts across many countries.
This document presents the progress of a research thesis evaluating the impacts of climate change on irrigated agriculture in the North Gojjam Sub-basin of Ethiopia. The study aims to assess climate trends, estimate current and future crop water demand under climate scenarios, and quantify climate change impacts on evapotranspiration, temperature, and rainfall. Methods include analyzing observed meteorological data, bias-correcting future climate projections, evaluating climate model performance, and using the CROPWAT model to estimate reference evapotranspiration and crop water requirements. Preliminary results show increasing temperature trends but decreasing rainfall trends in historical data, and future projections also indicate potential decreases in precipitation under climate change scenarios.
The document summarizes research on integrated water management of the Red-Thai Binh river system in Vietnam under changing conditions. The researchers used optimization methods to design reservoir operating policies that balance multiple objectives like hydropower production, flood control, and water supply. Climate change assessments showed vulnerabilities are amplified by operations and depend on uncertain future scenarios. Further research will introduce socio-economic factors and robust optimization to support adaptation strategy design.
This document describes a microfluidic method for measuring interfacial tension between immiscible fluids using a microfluidic device. The device contains two tapered microchannels connected by a pair of modified Laplace sensors. Interfacial tension is determined by monitoring the pressure drop across the microchannels where the interfaces are formed and measuring the curvatures of the interfaces. The method was tested using oil/water systems and results agreed well with a commercial tensiometry. This provides a low-cost and fast way to measure interfacial tension in microfluidics.
This document summarizes a research paper that compares two methods for estimating water losses from leakage in a water distribution system: minimum night flow analysis and hydraulic model calibration. Both methods were applied to an existing district metered area in southern Brazil. Minimum night flow analysis estimated daily real losses of 53.54 cubic meters, while hydraulic model calibration using Epanet Calibrator software estimated daily real losses of 49.73 cubic meters, showing similar results. The study concludes that calibration is a useful alternative to minimum night flow analysis for estimating leakage, as it allows visualization of the entire network hydraulics.
Modeling Water Demand in Droughts (in England & Wales)Ben Anderson
This document describes an agent-based microsimulation model for estimating domestic water demand under drought conditions in the UK. The model simulates individual households and factors that influence water usage, such as household attributes, appliances, practices, pricing, and drought interventions. Preliminary results show that including drought responses can reduce total water demand by 5% compared to not including responses. Further development of the model will add more influencing factors and link it to drought forecasts to better estimate future water demand scenarios.
This document presents a case study of coupling surface water and groundwater models in the Netravathi river basin located in southern India. It summarizes the data collected and methodology used. Key data included a digital elevation model, soil data, land use/land cover maps, rainfall and weather data, hydrological data including streamflow, and groundwater levels. The methodology involved using SWAT to model surface water hydrology and estimate groundwater recharge, then coupling the SWAT outputs to a MODFLOW groundwater model to allow a more complete analysis of the regional hydrological system.
18- (IBWRD) Developing an Optimal Design Model of Furrow Irrigation Based on ...Kaveh Ostad-Ali-Askari
This document presents a model for optimizing furrow irrigation design based on minimizing costs and maximizing irrigation efficiency. The model uses the Valiatzas equation to explicitly calculate advance time, an important parameter in irrigation planning. The objective function considers costs of water, labor, and digging furrows and ditches. Variables in the model include furrow length, inflow rate, cutoff time, soil characteristics, and irrigation requirements. The model is presented as a way to compute optimal design values and efficiency for different soil types and crops.
Similar to Water-Demand Growth Modelling in Puerto Ayora’s Water Distribution Network Using EPANET (20)
The study of spatial socio-economic development constitutes a significant field of analysis of innovation creation and diffusion. Understanding the spatial evolution of the different socio-economic systems in the age of globalization requires a synthesizing and integrated theoretical approach to how innovation is generated and replicated. This article aims to study three significant spatial socio-economic development theories –the growth poles, the clusters, and the business ecosystems. A literature review reveals that (a) the concept of growth poles concerns mostly the analysis of spatial polarization between specific territories and regions, (b) the clusters concept addresses the issue of developed inter-industrial competition and co-operation from a meso-level perspective, and (c) the analytical field of business ecosystems provides an evolutionary approach that can be valorized for all co-evolving spatial socio-economic organizations. In this context, an eclectically interventional mechanism to strengthen innovation is suggested. The Institutes of Local Development and Innovation (ILDI) policy is proposed for all firms and business ecosystems, of every size, level of spatial development, prior knowledge, specialization, and competitive ability. The ILDI is presented as an intermediate organization capable of diagnosing and enhancing the firm’s physiology in structural Stra.Tech.Man terms (strategy-technology-management synthesis).
The formulation and implementation of development plans serve as the benchmark for evaluating economic progress in different sectors of an economy. Since independence, successive administrations in Nigeria have paraded different economic development plans. At the continental level also, several development programmes have been articulated for driving development in the countries of Africa. Many times, supposed laudable economic programmes have failed to identify with the interest of citizens, largely due to poor communication of such programmes. This study investigated citizens’ participation in the implementation of Nigeria’s Vision 20:2020. Among others, the study asked the following questions: to what extent are Nigerian citizens aware goals of Vision 20:2020 economic blueprint? What were the media used in popularising Nigeria’s Vision 20:2020 economic blueprint? The study was anchored on the Participatory Development theory. The survey research design was used to study a population of 84, 004, 084 from which a sample size of 384 respondents was drawn. The sample was based on Keyton’s sampling system. Findings of the study showed that many citizens of Nigeria do not understand the goals of Vision 20:2020. It was also found out that many citizens of Nigeria cannot identify development projects executed in line with the goals of Vision 20:2020. Based on these findings, the study recommended, among other things, that the Nigerian government should partner with civil society organisations to popularise the goals of Vision 20:2020. It was also recommended that citizens of Nigeria should be encouraged to participate in the formulation and implementation of development programmes.
The central purpose of the study is to evaluate the programs, project planning and management in Ethiopian Red Cross society and its comparison with procedures of project planning and management system. The study found that Ethiopian Red Cross society has been working on a lot of community development projects in Ethiopia for several decades. Most projects were principally emphasized on disaster and risk reduction. Different organizations use diverse project procedures to achieve the anticipated objectives. This also true for the Ethiopian Red Cross society projects. The Ethiopian Red Cross society had integrated some unique style of project planning and management system in its project. Thus, there was no total departure in the whole system of project development phases. Every cycle of the project life spans are used beginning from the point of concept initiation to final implementation and closure phases.
Although Africa’s contribution to the world’s greenhouse gas emission is the smallest compared to other continents, yet they tend to be affected most by the variability in Climate. Malawi is not an exception to this climate change, as they are not just faced with rising temperatures and variable rainfall patterns, but with reoccurring droughts and severe flooding. Agriculture has been noted to contribute significantly to not only climate change but also has significant impacts on global warming through its greenhouse gas emissions. Nevertheless, not all farming systems impact negatively on climate change. Conservation Agriculture is a farming system that encourages no or minimum soil disturbance, maintenance of a permanent soil cover, and diversification of crop species. These three interlinked principles combined with good agricultural practices promote biodiversity and normal biotic processes, both on and under the ground surface, thereby increasing the productivity and nutrient use efficiency of water, into a more resilient farming system which will help sustain and improve agricultural production. This review looks at Conservation Agriculture practices in the Machinga Agricultural Development Division of Malawi and its role in climate change mitigation and adaptation. This paper shows that Conservation Agriculture has played an active role in the adaptation and mitigation of climate change effect by reducing atmospheric greenhouse gas emissions but suggested there is a need for the government to formulate a CA framework that is founded on the three interlinked principles and not just based on soil and water conservation principles which are currently being advocated and practised.
The study was conducted on issues affecting the academic achievement of female students in selected primary schools of Jimma Arjo woreda while its objective was to investigate the major factors that affect the academic achievements of female students in primary schools of four sampled primary schools/Arjo primary school, Andinnet, Arbi-gebeya and Wayu Warke primary schools. Female students academic achievements show an upgrading from time to time, but still the rise is delicate when contrast to males. The finding identified the five broad categories, Family related, school related, socio-economic related, cultural related were the major factors that affect the academic achievements of females’ education. The common issues household responsibilities, low awareness of parents towards females education, parents financial problems, parents education level, lack of school facilities, school distance, the nature of teacher student relationship, the study behavior female students implement, teaching method teachers use, early marriage, less avails of role models are the main reasons for squat academic achievements of female students on education. To alleviate these upward parents awareness to wards the benefit of educating females, motivating female students, providing financial supports for the poor female students, improving school facilities and protecting female from abduction and early marriage/from any harmful traditions were recommended.
The economic loss of timber caused by over stumps and defects is an essential issue in forest science but study regarding this is very limited in Nepal. Thus, this research was objectively conducted to assess the volume of timber loss and associated monetary loss caused by over stumps and defects in logs and reason behind this. Three community forests namely Deurali, Jay Durga and Raniphanta community forests were selected for this research. Total enumeration was done so 375 stumps and 224 defected logs were measured from15 March to 15 April, 2019. The height and diameter at the butt end were measured using simple tape and D-tape respectively. Additionally, the length and diameter of defects in log was recorded. Total thirty key informant interviews and three focus group discussions were organized to assess the major causes of over stumps and defects. The timber volume loss caused by over stumps was calculated using cylindrical volume formula and volume loss caused by defect was calculated using formula, i.e. gross volume - net volume. The price of wood was collected from community forest to calculate the monetary value of timber loss. The principal component analysis was applied to assess the major causes of over stumps and defect in log. The highest total volume loss was recorded around 15.217 m3 (28.49%) caused by over stumps and out of this, it was 53.41 m3 timber loss in Deurali community forest. The loss due to defects in tree was ranged from 128.57 to 284.21 m3 in the community forests. The monetary value of loss caused by over stump was US$ 6971.14 of Shorea robusta in Deurali community forest and it was US$ 8100.52 because of defect. The principal component analysis showed that use of saw and axe for felling the trees in the community forests was considered as highest factor of over stump and diseases and over mature trees were key factors of wood defect. The research will be useful for policy makers and scientific community to monitor the timber loss.
Background: The role of the pharmaceutical industry in a country such as Nigeria in the provision of safe, high quality and efficacious pharmaceutical products to meet the healthcare need of the populace, cannot be over-emphasized. This study was undertaken to critically look at the issues affecting Medicines’ Security in Nigeria. Methods: A self-completion questionnaire was used for data collection. The questionnaire was administered to participants of an Industry event in September 2017. Data collected were analyzed using Statistical Package for Social Science. Results: A total number of 800 questionnaires were administered to the participants and 529 of the questionnaires were included for analysis. Male participants (58.6%) were more than female participants, all age groups were well represented and more than a third of the respondents had first degree as their minimum qualification. Majority of the respondents (91.3%) indicated that Ministry of Health and its agencies were key to protecting the pharmaceutical sector, while slightly less of that proportion (79.1%) indicated that they patronized Nigeria pharmaceutical products. Almost all the participants (91.7%) supported the need for the local pharmaceutical industry to have access to sustainable funding and other incentives. A similar proportion (89.6%) of the respondents indicated that the local pharmaceutical industry should be prioritized in policy making and implementation. A significant proportion of the study participants (82.3%) indicated that access to medicines in Nigeria is a security issue. Conclusion: To ensure Medicines’ Security and attain medicines self-sufficiency in Nigeria, radical policies must therefore be put in place, together with enabling good business and industrial environment by the government in order to protect, promote and grow the local pharmaceutical industry in Nigeria.
Agricultural Informatics is a valuable domain in the field of interdisciplinary sciences. This is responsible for the applications of Information Technology, Computing and similar technologies into the agricultural activities. This is the combination of Agricultural Science and Information Sciences. The field due to technological nature is much closed with the Agricultural Engineering or Agricultural Technology. There are many allied and similar nomenclature of the fields but all of these are primarily responsible for the same purpose. The field is rapidly increasing in recent past and most practiced in the developed nation. However, in developing countries as well Agricultural Informatics becomes an emerging field of practice and growing rapidly. Agricultural Informatics is growing both in pre and post agricultural activity. This branch is considered as branch of Information Sciences & Technology due to its technological applications in the field of agriculture and allied areas. Information Sciences are the broadest field within the allied branches and growing rapidly. Agricultural Informatics educational programs have started in recent past in different level and stream of education viz. science and technology. However within the broad periphery of Information Sciences it could be offered in other streams and under the wide variety of Information Sciences. This paper is broad and interdisciplinary in nature and deals with the aspects of the Information Sciences and Technology including features, nature, scope and also the potentialities in respect of Agricultural Informatics.
Agriculture has been the major source of livelihood in Nigeria, primarily because the environment is favorable for Agricultural practice. On the basis of climate, topography and vegetation the country is divided into five agricultural zones, namely Dry sub humid, Sub-humid, very humid and swamp/flood. Subsistence agriculture formed the major system of farming in the olden days which provide food crops for human consumption, while surplus are transported to the local markets for sale. Subsistence agriculture also forms the basis upon which all other system of farming are built. Hence, this paper examines the problems and prospects of subsistence agriculture in Ibarapa East local Government Area of Oyo State. Ten farming centres were used as samples in the area. Questionnaires were used to collect relevant data. Percentage and T-test distribution techniques were used to analyze the data. The findings show that there is low agricultural production in the study area as a result of problems such as shortage of fund, land tenure system, inadequate transportation system among others.
One of the most burning issues that have dominated the public sphere in Nigeria and other oil exporting countries is the covid-19 pandemic and its attendant challenges. This pandemic is a shock on real economic fundamentals and frictionless of the market. It introduces a barrier between the market forces with strong complementary feedbacks in the real economy. The absence of precise vaccine or medication for the virus has necessitated the adoption of several precautionary measures with the aim of containing its wide spread. Critical among which are the travel restrictions, lockdown measures as well as social and physical distancing. These measures have detrimental effect on the demand and price of oil in the international market. In view of that, this study evaluates the social and economic impact of covid-19 in Nigeria taking into cognisance the effect on certain critical macroeconomic indicators. The study adopted an analytical approach to supplement the much ongoing documentations on the subject matter. Result shows that virtually all essential macroeconomic indicators are grossly affected with tax, remittances and employment exhibiting severe consequences. Also, uncertainty, panics and lockdown measures are key to motivating higher decrease in world demand. The supply disruptions and huge death toll generates a heightened uncertainty and panic for household and business. This uncertainty and panic leads to drop in consumption and investment thereby causing a decrease in corporate cash flows and triggered firm’s bankruptcy. Also, lay-off and exiting firms produce higher unemployment while labour income decreased significantly. Since it entails a large amount of government expenditure especially in the health sector which is required to contain the spread of the virus, there is needs for government to diversify its revenue sources and thus drop over dependency on the oil remittance. Furthermore, there is a need to support the financial system to avoid the health crisis becoming a financial crisis in the long-run.
The outbreak and subsequent spread of COVID-19 to the West African sub-region have brought significant changes to the different aspects of our lives and grounded educational and socio-political and economic activities of ECOWAS member states. The pandemic has exposed the poor state of the health systems and shortage in medical supplies and protective gears to cope with the health emergency. In response, strict restrictions were put in place to curb the spread of the virus and these have drastically affected peoples’ lifestyles. However, there has been huge increase in the use of technology in business, education, religion and other activities as people adapt to the changing times in the sub-region. It is the argument of this paper that things cannot return to the way they were before the pandemic, but West African states must strategically plan for the Post COVID-19 era to survive the massive wave of unemployment, socio-economic meltdown and changes in lifestyle. The paper concluded that while the fight against the virus in the sub-region was not collective, post-pandemic recovery must be coordinated, strategically plannedamong member states. It was recommended that the governments should be flexible enough to retain the use of ICT and technology alongside the conventional ways of doing things in the post-pandemic era.
Undoubtedly, religion is one of the main factors that increasingly contribute to the shaping of international relations. As it was in the European middle ages, religion and geopolitics have always had ties of one sort or another. Imperialism and nationalist doctrines have found purpose and justification in religious differences and, religious zealotry was functioned to be both cause and consequence of the concentration of state power and the rivalries among existing competitors. The involvement of numerous religious groups and movements in the political scene led the situation to be extremely complicated. The purpose of this article is to see to what extent religion as a soft power has a role in forming international politics. Also, to discuss the role the superpowers and regional powers play in dealing with the question of religious issues. With an argument that these issues including religious conflicts are led by international and regional powers which function these groups in a proxy war to be part of their rivalry overpower, and to achieve their national interests through their foreign policies at the cost of considerable environmental degradation and a massive death toll of people.
This study examines and explicates the lexico-semantic parameters, which Joseph Edoki deploys to convey his themes in The Upward Path, his second novel. Edoki is a contemporary Nigerian novelist who is preoccupied with the socio-political problems in Africa with the hope of a brighter future. The novel is the story of Mr. Gaga, a Rhwandan American PhD student, on a fact finding mission in Savannah, an African country, for his Thesis entitled ‘’ Why Africa is Underdeveloped’’. For failing to portray Africa in line with the negative views about the continent in his proposal, Gaga’s supervisor recalls him back to America in anger. But in defense of his conviction and research findings about Africa, Gaga remains in Savannah to complete his Thesis. This study is of significance because as a linguistic study, it will serve as a springboard to future researches in the language of African literature. Moreover, the good governance, which Edoki presents in Savannah, the fictional country, in which the novel under study is set, is a blue print for the development of Africa.
The increasing involvement of women in the advancement of insurgency in Nigeria has become a thing of great worry. The question often asked is as to whether their involvement is induced or free-willed. The concept of consent is on different layers and one would imagine the extent of consent given before they become members of the sect or culprits. The different ways women have been used to perpetrate the activities of Boko Haram ranges from threats to abuse, Indoctrination to hypnotism and many others. Due to the subtle and unsuspecting nature of women, they form a good strategy for members of the sect. However, their involvement is not evidence against them as they face situations that almost deny them the opportunity to choose whether or not to subscribe to the forceful approach used by Boko Haram insurgents!.
The art of using language for public expression in order to persuade target audience to support development initiatives is a key reason for graphic communication. This requires communication actors particularly, the graphic encoder to know salient input and output variables of communication for effective mediation. However, the prevalence ignorance of these variables, often results in ineffective media production that is counter-productive to development. Therefore, this paper focused on production of practical rhetoric in graphic language for development programmes. The paper employed the critical-historical-analytic examination and content analysis methods. It introduced the reader to the need for practical rhetoric in visual communication. Furthermore, it highlighted the salient input and output variables that the graphic communication actor need be conversant with in order to produce visual rhetoric, using the McGuire’s Communication/persuasion Matrix. And it exemplified graphic media that result from application or neglect of the knowledge of the variables. The paper found that consideration of the variables afforded production of effective rhetoric in graphic language. The paper ended with the need for graphic encoders to internalize knowledge of the input and output variables and utilize it during the process of media production to generate visual rhetoric with desired effect.
The Niger delta of Nigeria has been besieged by a lot of crises, which have posed serious security risks to the region. This has adversely and seriously affected not only the region, but Nigeria in general. The processes of crude oil extraction in the Niger delta have resulted in ecological degradation and oil pollutions, thereby doing a lot of damages to the farmlands and fishing waters of the people, whose major occupations are farming and fishing. Petroleum, the main source of Nigeria’s revenue is obtained in the Niger delta. Yet, Deltans are confronted with a lot of problems; they are impoverished, exploited, neglected and marginalized despite the economic value of the region to the Nigerian economy. No serious or commensurate efforts are made by the government or the multinational oil companies operating in the region to compensate the people for the losses they suffer through oil pollutions. This has resulted in a lot of protests and violence, culminating in the social unrest in the region. To this effect, there have been reactions to the crises in diverse ways. Though such efforts have yielded little dividends, the crises have persisted. Niger delta deserves priority attention in terms of human and infrastructural developments. In the literary circle, some Nigerian literary artists have expressed concern over the issue with a view to creating awareness on the seriousness of the crises, and advancing suggestions that will proffer permanent solutions to the problems. This paper examines and expounds how Helon Habila deploys the mood system as a language tool in his novel, Oil on Water, to address the Niger Delta crises. He advances suggestions to put an end to the crises in order to restore peace, and enhance sustainable development in Nigeria.
The paper seeks to analyze the larger concept of multiculturalism and to further determine its role and importance in modern Georgia. The agenda of cultural diversity is often subject to criticism, accused for being responsible for endangering modern societies. Such statements will be critically analyzed within the context of the increasing far-right sentiments among Georgians, as reflected in a what can be described as a radical march which took place in Tbilisi on the 14th of July 2017, creating risks of further deteriorating of the situation in the country, given the general macro-economic instability of Georgia and undermining democracy. This paper concludes that it is very important to establish an innovative new model of Georgian citizenship, and one which will address all the accumulated misunderstandings now existing in society. It is expected that this will enable multiculturalism to be perceived more appropriately, i.e. as a unifying ideology rather than a dividing force.
The purpose of the research is to examine importance of Georgia’s current relations with its neighboring Russia and Azerbaijan and to estimate risks that deterioration of these relations can bring to Georgia’s economy. Of particular interest is to understand who stands behind the tensions happened in Georgia in the run-up to the tourist season of 2019 or at least to figure out possible motives behind the events. Interdependence of the states is analyzed through historical review of their relations and estimation of their current mutual interests. Considering risks and aspirations of the sides in the tensions, the motives behind are suggested. The data received depicts that none of these tensions were initiated by Georgia following its interests, on the contrary, its ruling party’s most visible achievement had been the ability to maintain positive and beneficial relations with both Russia and Azerbaijan. Thus, the Georgian government considered to be a victim in this case. The paper concludes that Georgian government is unable to react on provocations in a timely fashion due to absence of agreement in the ruling party and being quite fragile for outside forces that try to influence the country’s political processes. Unless Georgia manages to build more interdependent or less dependent relations with superpowers, it will be unable to avoid repetition of such manipulations.
This study explores a potential reposition of the triple helix model of university-industry-government relations in terms of micro-level analysis. In this direction, we evaluate the development of helix theory over time, by reviewing the relevant literature divided into three successive phases: the phase of theoretical foundation, the phase of conceptual expansion, and the phase of recent developments and systematic attempts of implementation. In this conceptual study, we estimate that a refocused triple helix model in terms of local development, by placing at the center of analysis the “living organization’s” dynamics in Stra.Tech.Man terms (synthesis of Strategy-Technology-Management), can be a possible direction of analytical enrichment.
The document analyzes the dynamic relationship between global oil prices and the exchange rate of the Eswatini currency (SZL) against the US dollar using daily data from 2005 to 2018. It finds a unidirectional causal relationship from global oil prices to the SZL/USD exchange rate using the Toda-Yamamoto Granger causality test, indicating that global crude oil prices influence Eswatini's nominal exchange rate. The study recommends that Eswatini's exchange rate policy consider global oil price movements to avoid misalignment of its currency.
More from International Journal of World Policy and Development Studies (20)
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
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with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
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‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
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The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
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ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
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Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
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Exposé invité Journées Nationales du GDR GPL 2024
Water-Demand Growth Modelling in Puerto Ayora’s Water Distribution Network Using EPANET
1. International Journal of World Policy and Development Studies
ISSN(e): 2415-2331, ISSN(p): 2415-5241
Vol. 5, Issue. 8, pp: 71-81, 2019
URL: https://arpgweb.com/journal/journal/11
DOI: https://doi.org/10.32861/ijwpds.58.71.81
Academic Research Publishing
Group
*Corresponding Author
71
Original Research Open Access
Water-Demand Growth Modelling in Puerto Ayora’s Water Distribution
Network Using EPANET
María Reyes*
Environmental Engineering and Water Technology Department, IHE Delft (Institute for Water Education), Netherlands
Nemanja Trifunović
Environmental Engineering and Water Technology Department, IHE Delft (Institute for Water Education), Netherlands
Saroj Sharma
Environmental Engineering and Water Technology Department, IHE Delft (Institute for Water Education), Netherlands
Maria Kennedy
Environmental Engineering and Water Technology Department, IHE Delft (Institute for Water Education), Netherlands
Faculty of Civil Engineering and Geosciences, Delft University of Technology, The Netherlands, Netherlands
Abstract
This paper elaborates the hydraulic characteristics of the water supply network of the town of Puerto Ayora. First, it
intends to replicate the household individual storage by simulating nodal tanks with the use of the EPANET
software. Later, it uses the Pressure-Driven Approach (PDA) to develop a methodology that estimates the overflow
of storage facilities, one of the main sources of wastage in Puerto Ayora. Finally, it uses the Demand-Driven
Approach (DDA), with the aim of assessing the network in the future, under four population growth scenarios. With
the chosen moderate growth scenario, two options are suggested in order to tackle the water supply issues at the end
of the planning horizon.
CC BY: Creative Commons Attribution License 4.0
1. Introduction
Water demand tends to exceed the available supply capacity, especially in many developing countries, as a
result of rapid population growth (Ingeduld et al., 2006). As a consequence, Intermittent Water Supply (IWS)
regimes are introduced with the aim of limiting that demand. Water scarcity in arid regions is also amplified when
there is a lack of conveying capacity in the distribution network, which is too deteriorated to deliver the required
demands (Ameyaw et al., 2013). Even though the water distribution should be equitable and efficient in such cases
(Vairavamoorthy et al., 2008), IWS have become a norm rather than an exemption (Seetharam and Bridges, 2005),
mainly due to necessity rather than the initial design (Vairavamoorthy et al., 2007).
IWS varies depending on the region and situation, ranging from a few hours per day to a few hours per week.
Therefore, in order to compensate the periods of interruption, end-users need to store as much water as possible
during service hours. Therefore, the water distribution is not homogenous, creating high peak factors and inadequate
pressures in the distribution system (Andey and Kelkar, 2009). Consequently, the system becomes unreliable due to
pumps and pipes failing to carry the required water during supply (Ameyaw et al., 2013).
Individual storage facilities, usually tanks, play important role in IWS systems, since these are the solely supply
at moment of unavailability. The water inflow into each household tank relies on the pressure conditions in the
network and it equals to the maximum amount of water that can be collected during the supply hours (Ingeduld et
al., 2006). Therefore, water demand balance takes place for each individual household storage tank, “whereby
replenishing of the volume behaves differently depending on water availability in the distribution network”
(Trifunović and Abu-Madi, 1999). Furthermore, the water is consumed according to the demand patterns which are
not necessarily influenced by the IWS regime, but rather by common household habits and activities.
1.2. Case Study Description
Tourist islands face additional pressure when tackling scarcity, while aiming to optimise the revenues from
tourism and providing sufficient environmental protection at the same time. Puerto Ayora as the main tourist hub of
Santa Cruz Island, has a distribution network built approximately in the 1980’s, which has 2500 service connections
and supplies intermittently brackish water to approximately 12,000 inhabitants (INEC, 2010). Due to the lack of
proper maintenance, the network is characterized by high leakage levels whose actual figure are still not confirmed.
Most premises in this town have storage facilities, mainly in the form of roof-tanks and/or cisterns, perceiving the
supply as unreliable and insufficient. On the other hand, the fixed water-tariff structure seems to be the main cause
of excessive water wastage within the premises. In short: the municipal supply service has not been able to cope with
current tourist growth trends (Reyes Pérez, 2017).
2. International Journal of World Policy and Development Studies
72
The aim of this paper is to analyse the performance of the current hydraulic network in Puerto Ayora, evaluating
the water losses from spilling of roof tanks. During fieldwork data collection, a peculiar situation was observed
regarding the overwhelming amount of wastage from the overflow of roof-tanks. The origin of this type of losses
seems to be due to the absence of floating valves and the fact that the faucets are not closed when the tank is already
full. Therefore, a methodology was developed for the quantification of water overflow of household-roof tanks,
which further questions the currently applied IWS regime using the EPANET model. The hydraulic simulations for
the current study were conducted by running the Pressure-Driven Analysis (PDA) feature of the EPANET software,
while the future demand scenarios were simulated by the Demand-Driven Analysis (DDA).
2. Demand-Driven Analysis (DDA) and Pressure-Driven Analysis (PDA)
The default hydraulic solver for water network modelling commonly uses the Demand Driven Analysis (DDA).
DDA assumes that nodal demands are known functions of time, and are independent of the available pressure in the
distribution system (Cheung et al., 2005). The hydraulic solver produces the nodal pressures and pipe/pump flows
which satisfy those fixed nodal demands. The DDA under regular supply conditions presents a reasonable and close-
to reality solutions, assuming that the nodal demands are always delivered. The algorithm in the modelling software
is able to formulate the needed equations in order to solve the unknown nodal heads (Ozger and Mays, 2003),
regardless of the pressures throughout the distribution system. However, these algorithms are unable to capture
precisely the how intermittent systems behave, operating under irregular conditions.
The studies developed by Germanopoulos (1985), Martinez et al. (1999), Soares et al. (2003), Hayuti and
Burrows (2004) and Tanyimboh et al. (2004), discuss the restrictions of DDA. On the contrary, these studies suggest
that the use of the PDA, which assumes a fixed demand above given pressure threshold, zero demand below the
given minimum pressure, and proportional relationship between the pressure and the demand for the pressure range
between the threshold and the minimum values is a more reliable method in irregular situations (Cheung et al.,
2005). The PDA approach aims to replicate a pressure-demand relation in the modelling process, using the concept
of orifices at system nodes. Consequently, the previous-mentioned studies suggest that PDA tend to be more
effective than DDA at the moment of simulating intermittent water supply conditions.
Tanyimboh et al. (2001), describe the PDA relationship as follows (Reyes Pérez, 2017):
n
iiii QKHH min
(Equation 1)
where Hi represents the actual head at demand node i, Hi
min
refers to the minimum head to which below the
service ends, Ki is the resistance coefficient for node i, Qi refers to the nodal discharge flow, and n is the exponent
that theoretically and usually takes the value of 2.0 (Gupta and Bhave, 1996). Furthermore, if the value of Qi is
unknown for any given nodal head, then Equation 8.1 needs to be rearranged as follows:
n
i
ii
i
K
HH
Q
/1
min
(Equation 2)
If Qi equals the required demand, Qreq, Hi should then equal the desired head in the node, named Hdes. If the
demand at that node further needs to be fully satisfied, then the head should be available as follows:
n
i
des
i
req
i
n
i
n
i
i
des
ireq
i
HH
Q
KK
HH
Q /1min/1
/1
min
1
(Equation 3)
Finally, Equation 4 is obtained by substituting Ki in Equation 8.2:
n
i
des
i
i
avl
ireq
i
avl
i
HH
HH
QQ
/1
min
min
(Equation 4)
where Qi
avl
refers to the flow for the head available at the node (Hi
avl
). Equation 4 has three probable situations:
1)
0min
avl
ii
avl
i QHH
2)
req
i
avl
i
des
i
avl
ii QQHHH 0min
3)
req
i
avl
i
des
i
avl
i QQHH
These situations are used when balancing the flows in the pipes, which are connected to node i. The key issue is
the correct definition for Hi
min
and Hi
des
, such as their correlation with the nodal resistance Ki, which is the one that
describes the nature of the PDD empirical relationship.
The EPANET software, developed by Rossman (2000) uses the PDA concept through Emitter Coefficients
(EC), which model pressure-dependant flows from sprinkler heads. The concept of EC is described by using similar
relationships as in Equation 1. In this case, an emitter is modelled as a dummy pipe connected to the actual demand
node, with a dummy reservoir whose nodal elevation (z) equals the initial head. Hence, Hi
min
= zi and:
n
iin
i
i zH
K
Q
1
1
1
(Equation 5)
3. International Journal of World Policy and Development Studies
73
The K-value in Equation 5 refers to the resistance of the dummy pipe, but actually it has the same meaning as in
Equations 1 to 3. Finally,
i
iii
ii
ii
K
knzH
g
p
g
p
kQ
1
;1;;
(Equation 6)
where ki is the EC in node i and α is an emitter exponent with theoretical value of 0.5. EC was first introduced to
simulate operation of fire hydrants.
In order to use the PDA accurately, it is required extensive field data collection in order to determine the
relationship between nodal heads and flows (Ozger and Mays, 2003). Other PDA approaches have been based on
further improvement of the EC concept of the EPANET, such as the one by Pathirana (2010).
3. Methodology
The gravity hydraulic network model was built in the EPANET software, as shown in Figure 1, which consists
of two reservoirs, 284 nodes and 367 pipes. The estimation of nodal demands was done based on the total population
and an estimated demography per m2
, using the demand patterns established for this particular case study found in
Reyes et al. (2017b).
Figure-1. Layout of Puerto Ayora water supply network
To check the numerical stability, as well as the robustness of the EPANET program, each node was modelled as
being connected to a tank, which’s was calculated by the number of occupants supplied at that node, and the
elevation determined was that corresponding to that node; this model is shown in Figure 2. An average tank height of
1.5 m above the ground level average, as well as an average of five inhabitants per household was assumed. All
tanks were assigned the initial depth of 1 m, the minimum depth of 0 m, and the maximum depth of 3 m. Also, a
check-valve was modelled with a short dummy pipe, in order to prevent backflow from the storage tank (i.e simulate
the inlet arrangement from the top).
Figure-2. Outlay of Puerto Ayora’s network modelled with roof tanks
4. International Journal of World Policy and Development Studies
74
Also, as an alternative, the PDA approach was simplified in order to translate the rationing as it is applied in
reality. To make this possible, the network modelled with EC was divided into five small sub-systems (Figure 3),
representing each distribution zone created by the municipality. In order to match the previously reported total
amount of supply per day, which is approx. 5000 m3
for the horizon 2015, including the leakage (Reyes et al., 2016),
different EC values were tried for each zone and supply hours, adopting an EC value of 0.5.
Figure-3. Layouts of zones divided by distributed supply according to the Municipality of Santa Cruz (Reyes Pérez, 2017).
(a) – supply from 11 to13 hrs. (b) – supply from 13 to 16 hrs.
(c) – supply from 9 to 11 hrs. (d) – supply from 16 to 18 hrs.
(e) – supply from 6 to 9 hrs.
The assessment of the overflow of the nodal tanks was done per zone, using several scenarios created by varying
the leakage, the average volume of individual storage tanks, and the percentage of the tank level at the moment the
water supply starts in a particular distribution zone.
5. International Journal of World Policy and Development Studies
75
The volumes considered in making the balance for each node of the five sub-models are further shown in
Equations 7 – 10 (Reyes Pérez, 2017).
1, XnV ih
avl
i
(Equation 7)
Vi
avl
is the total available individual storage volume in node i (in m3
), nh,i is the number of households served
from the node, and X1 is the variable that indicates the average storage volume available per household (m3
).
2,
24
XnV ic
c
i
(Equation 8)
Vi
c24
is the total volume consumed in node i over 24 hours (in m3
), nc,i is the number of consumers served from
the node, and X2 is the variable that indicates the average specific demand per capita (lpcpd).
100
1 324 X
hQV s
i
EC
i
s
i
(Equation 9)
Vi
s24
is the total volume supplied to node i over 24 hours (in m3
); this is an IWS that occurs during hi
s
hours at
the flow Qi
EC
(in m3
/h) based on the available pressure calculated in EPANET using the emitter coefficients. X3 is the
variable that indicates the average leakage percentage in node i.
ij
h
j
c
icIWS
i pf
V
V
s
i
,
1
24
24
(Equation 10)
Vi
cIWS
is the total volume consumed in node i (in m3
) during the IWS period of hi
s
hours, at hourly peak factors
pfj,i applied depending on the period of the day when the IWS takes place (for the diurnal patterns, see (Reyes et al.,
2017a). Hence, the actual volume accumulated in the tank(s) of node i during the IWS period is Vi
s24
– Vi
cIWS
.
Assuming X4 to be the variable that indicates the percentage of the total available volume Vi
avl
already occupied at
the moment when the IWS starts, the buffer of volume in the tank(s) of node i, Vi
buf
, when the IWS stops, will be:
cIWS
i
s
i
avl
i
buf
i VV
X
VV
244
100
1
(Equation 11)
Possible negative result in Equation 11 will indicate the overflow i.e. the spilling from the tank(s) of node i.
Furthermore, when the IWS stops, the tank(s) will be discharged for the volume Vi
c24
– Vi
cIWS
suggesting the initial
volume before the IWS starts again to be:
Vi
avl
– (Vi
c24
– Vi
cIWS
), if the overflow was taking place during the IWS (Vi
buf
< 0);
Vi
avl
– Vi
buf
– (Vi
c24
– Vi
cIWS
), if the overflow was not taking place during the IWS (Vi
buf
≥ 0).
In both of these cases, the result can in theory be negative, suggesting the water shortage and/or insufficient
volume of the tanks. Assuming that this is not the case, some indication exists while assessing the values for X4.
For instance, a sample calculation done for IWS Zone 1 shown in Figure 3(a) is given in Table 1, taking X1 = 1.5
m3
, X2 = 163 lpcpd, hi
s
= 2 hours, X3 = 17.5%, pf1 = 1.29, pf2 = 1.66, and X4 = 0. With these, the total overflow
amounts at approximately 114 m3
, which is about 42% of the total volume supplied (of 269 m3
).
Table-1. Estimation of tanks’ volumes of overflow in IWS Zone 1
nc,i nh,i Vi
avl
(m3
)
X2
(lpcpd)
hi
s
(hours)
Vi
c24
(m3
)
V1
cIWS
(litres)
V2
cIWS
(litres)
Qi
EC
(l/s)
Vi
s24
(m3
)
Vi
s24
–
Vi
cIWS
(m3
)
Vi
buf
(m3
)
J-1 31 6 6.2 163 2 5.1 272.9 351.2 2.1 12.4 11.7 -5.5
J-2 29 6 5.8 4.7 252.1 324.4 2.0 12.1 11.5 -5.8
J-3 18 4 3.6 2.9 157.0 202.1 2.1 12.5 12.2 -8.6
J-42 15 3 3.0 2.5 133.1 171.3 2.1 12.4 12.1 -9.1
J-43 27 5 5.4 4.4 238.1 306.4 2.0 11.8 11.3 -5.8
J-44 15 3 3.0 2.5 132.2 170.1 2.0 11.8 11.5 -8.5
J-45 27 5 5.3 4.3 233.3 300.2 2.1 12.5 11.9 -6.6
J-46 39 8 7.8 6.4 342.1 440.3 2.0 11.9 11.2 -3.4
J-47 23 5 4.5 3.7 198.8 255.8 2.1 12.6 12.1 -7.6
J-48 47 9 9.3 7.6 408.9 526.2 2.0 11.6 10.7 -1.3
J-50 27 5 5.4 4.4 238.3 306.7 1.8 10.5 10.0 -4.5
J-64 28 6 5.7 4.6 249.4 321.0 2.0 11.7 11.1 -5.4
J-65 54 11 10.9 8.8 475.7 612.1 2.1 12.5 11.4 -0.5
J-66 27 5 5.4 4.4 237.6 305.8 2.1 12.5 11.9 -6.5
J-67 44 9 8.9 7.2 389.5 501.3 2.0 12.1 11.2 -2.3
J-68 28 6 5.6 4.5 244.3 314.3 2.2 12.8 12.3 -6.7
J-69 35 7 7.1 5.8 311.0 400.2 2.2 13.2 12.5 -5.4
J-70 29 6 5.8 4.7 254.1 326.9 2.0 12.1 11.5 -5.7
J-78 54 11 10.8 8.8 473.6 609.4 2.1 12.7 11.6 -0.8
J-79 47 9 9.3 7.6 407.9 524.9 2.0 11.8 10.9 -1.6
J-80 26 5 5.2 4.2 227.6 292.9 2.0 11.7 11.2 -6.0
J-81 34 7 6.8 5.5 298.0 383.5 2.3 13.5 12.9 -6.1
Source: Reyes Pérez (2017)
6. International Journal of World Policy and Development Studies
76
This assessment was carried out for the entire network, and the influence of each variable was further evaliated.
Finally, the water supply network was assessed for the future demand under the same four tourist and local
population growth scenarios used in Chapter 6 (Mena et al., 2013). The analysis was done in the intervals of five
years, as shown in Table 2. The same growth rate was used for all nodal demands, while the tourist demand was
distributed amongst the nodes located in the center of the town (where most of the tourist facilities are).
Table-2. Local and tourism population growth estimations for 30 years planning horizon in Puerto Ayora
YEAR Total
growth
rate
Local
population
(inhab.)
Demand local
population
(m3/day)
No. of
tourists/
year
Tourist
consumption
(m3/day)
SLOW GROWTH
2015 - 15,801 2,576 205,505 1,109
2020 0.05 16,607 2,707 215,780 1,165
2025 0.10 17,454 2,845 226,055 1,220
2030 0.15 18,345 2,990 236,331 1,276
2035 0.20 19,280 3,143 246,606 1,331
2040 0.25 20,264 3,303 256,881 1,386
2045 0.30 21,087 3,437 267,156 1,442
MODERATE GROWTH
2015 - 15,801 2,576 205,505 1,109
2020 0.15 18,318 2,986 236,331 1,276
2025 0.30 21,235 3,461 267,156 1,442
2030 0.45 24,618 4,013 297,982 1,608
2035 0.60 28,539 4,652 328,808 1,775
2040 0.75 33,084 5,393 359,634 1,941
2045 0.90 37,236 6,070 390,459 2,107
FAST GROWTH
2015 - 15,801 2,576 205,505 1,109
2020 0.25 20,167 3,287 256,881 1,386
2025 0.50 25,738 4,195 308,257 1,664
2030 0.75 32,849 5,354 359,634 1,941
2035 1.00 41,925 6,834 411,010 2,218
2040 1.25 53,508 8,722 462,386 2,496
2045 1.50 65,040 10,601 513,762 2,773
VERY FAST GROWTH
2015 - 15,801 2,576 205,505 1,109
2020 0.35 22,174 3,614 277,432 1,497
2025 0.70 31,116 5,072 349,358 1,886
2030 1.05 43,665 7,117 421,285 2,274
2035 1.40 61,275 9,988 493,212 2,662
2040 1.75 85,987 14,016 565,139 3,050
2045 2.10 112,759 18,380 637,065 3,438
Source: (Reyes Pérez, 2017)
4. Modelling, Results and Discussion
4.1. Current Situation Simulated with Nodal Tanks
The fist simulation was conducted with the network model shown in Figure 2. This model indicates 578 nodes,
286 tanks and 940 pipes. The latter originates from the setup of the discharge from the tanks that consists of a
dummy pipe attached to the node with a consumption pattern, and another dummy pipe on the upstream side of each
tank, representing a check-valve; shown in Figure 4. The model setup becomes rather bulky; however it is the only
way to reflect the actual reality.
After several attempts, the simulation runs did not presented any tangible result. First of all, the model appeared
to be very sensitive to the selection of the tank properties and the initial water levels. As soon as the tank gets
emptied or filled from the imbalance between the demand and supply, based on the EPANET settings, the tank
becomes disconnected from the network. This suggests that this inflicts numerical instability, which was also
experienced by significantly longer simulation times than usual, and resulting in negative pressures in the network.
Figure 4 shows the documented negative pressures in the model, while Figure 5 shows the trends of water level
variation in randomly selected tanks in the same distribution area.
7. International Journal of World Policy and Development Studies
77
Figure-4. Layout of Puerto Ayora’s network with nodal tanks
Figure-5. Pressures over 24 hours for randomly selected tanks
Therefore, the calibration of such a model appeared to be very complex and it suggested that the amount of
tanks influenced somehow; the model could work only if these are not entirely emptied or completely full. The
model becomes unstable and might only work if all the tanks have sufficient amount of water throughout the entire
day. In that case, analyses of irregular water distribution schemes become very challenging, and the other approach
was tested.
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78
4.2 Results of Pressure-Driven Approach with Emitter Coefficients
The alternative way of modelling was therefore adopted using the approach illustrated by Equations 7 to 11 and
in Table 1. The 16 selected scenarios based on the values X1 to X4 and the results showing the buffer volume are
shown in Table 3. Two specific demand scenarios (X2) correspond to the figures obtained by the field survey
described in Reyes et al. (2017b). Similarly, the leakage scenarios (X3) were set by assuming the physical leakage to
be 50% of the total NRW levels (assessed at 35 and 50%, respectively). The negative buffer indicates the spilling
from the tanks with the 2nd
figure showing the value reduced for 30%, which is believed to be the percentage of the
households having the float valves installed on their roof tanks.
Table-3. Scenarios for the estimate of tank overflows in Puerto Ayora
X2
(lpcpd)
X3
(%)
X1
(m3
)
X4
(%)
Vi
buf
(m3
)
Vi
buf
(2)
(m3
)
% total daily supply
163 Scenario 1
17.5 1 0 -1327 -929 18.6
Scenario 2
17.5 1 50 -2301 -1611 32.2
Scenario 3
17.5 2 0 -423 -296 5.9
Scenario 4
17.5 2 50 -709 -496 9.9
Scenario 5
25 1 0 -1053 -737 14.7
Scenario 6
25 1 50 -1957 -1370 27.4
Scenario 7
25 2 0 -287 -201 4.0
Scenario 8
25 2 50 -1053 -737 14.7
195 Scenario 9
17.5 1 0 -1285 -900 18.0
Scenario 10
17.5 1 50 -2239 -1567 31.3
Scenario 11
17.5 2 0 -411 -287 5.7
Scenario 12
17.5 2 50 -1285 -900 18.0
Scenario 13
25 1 0 -1016 -712 14.2
Scenario 14
25 1 50 -1900 -1330 26.6
Scenario 15
25 2 0 -298 -208 4.2
Scenario 16
25 2 50 -1016 -712 14.2
Source: Reyes Pérez (2017)
In terms of the percentage of daily supply, the results show a wide range between 4.2 and 32.2 %, which
indicates sensitive input data. Based on the field observations at the case study area, it is believed that Scenario 6
may be the closest to the reality, with remark that the tank levels at the beginning of the IWS next day may vary in
filling percentages, which depends on the consumption pattern of the previous day; hence, the values of X4 need
specific validation compared to the other three variables.
Based on the results in Table 3, an assessment carried out to calculate the additional supply in case the overflow
from the tanks could have been prevented. Table 4 shows the additional population that could be supplied for each of
the 16 chosen scenarios, assuming two specific demands used in the analysis of the tank buffers. As can be observed,
in the most extreme situation of Scenario 2, almost 60% of additional population could have been supplied at the
lower specific demand of 163 lpcpd, and nearly 50% at the higher one of 195 lpcpd. These results put a valid
hypothesis about the actual necessity of the roof tanks, since they may not be easing the current intermittent
situation, but actually boosting it, resulting from the negligence of local population.
9. International Journal of World Policy and Development Studies
79
Table-4. Additional population to be supplied based on different overflow scenarios
Scenarios Specific Demand
of 163 lpcpd
Percentage of
population
Specific Demand
of 195 lpcpd
Percentage of
population
1 5697 33.5 4762 28.0
2 9882 58.1 8261 48.6
3 1817 10.7 1519 8.9
4 3043 17.9 2543 15.0
5 4521 26.6 3779 22.2
6 8403 49.4 7024 41.3
7 1234 7.3 1032 6.1
8 4521 26.6 3779 22.2
9 5519 32.5 4614 27.1
10 9614 56.6 8036 47.3
11 1763 10.4 1474 8.7
12 5519 32.5 4614 27.1
13 4365 25.7 3649 21.5
14 8158 48.0 6819 40.1
15 1278 7.5 1068 6.3
16 4365 25.7 3649 21.5
Source: (Reyes Pérez, 2017)
The sensitivity of the four X-variables was further analysed against the tank overflow in somewhat wider range
than the one applied in the 16 scenarios. Figure 6 shows that the highest sensitivity belong to the variables X1 and X4,
which underpins the need for further fieldwork in order to validate the available volume (individual household
storage), and the initial level of the tanks before the IWS kicks-off every day. On the other hand, the specific
demand, as well as the average leakage percentage, influence the overflow volume to a lesser extent.
Figure-6. Sensitivity analysis based on different (a) individual tank volume, (b) specific demand, (c) leakage level and (d) tank level in total
overflow estimation
(a) (b)
(c) (d)
5. Conclusions
Three modelling approaches illustrated in this paper, included nodal tanks, the PDA and the DDA, for the
current demand in Puerto Ayora. In the first case, it was very complicated to replicate the actual individual storage in
the model. The EPANET software becomes unstable due to different water level patterns in each tank, sometimes
full and sometimes empty. More detailed information would be needed for a proper calibration of such a model but
even then it is possibly that the model could perform only regular demand scenarios. Unfortunately, EPANET
disconnects empty tanks which distorts its numerical stability in multiple occurrence of this situation.
0
500
1000
1500
2000
1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
Overflow(m3)
X1 (m3)
0
500
1000
1500
2000
163.0 166.2 169.4 172.6 175.8 179.0 182.2 185.4 188.6 191.8 195.0
Overflow(m3)
X2(lpcpd)
0
500
1000
1500
2000
17.5 18.3 19.0 19.8 20.5 21.3 22.0 22.8 23.5 24.3 25.0
Overflow(m3)
X3 (%)
0
500
1000
1500
2000
2500
0.0 7.5 15.0 22.5 30.0 37.5 45.0 52.5 60.0 67.5 75.0
Overflow(m3)
X4(%)
10. International Journal of World Policy and Development Studies
80
The PDA of present demand reflects partially the situation with the household storages. The aim was to estimate
the overflow of roof tanks under several scenarios. As observed from the results, it can be concluded that there may
be a significant amount of water lost due to the overflow of the roof tanks. The local authorities in Puerto Ayora, as
well as local residents, have the erroneous idea of the “need” for individual storage to compensate the lack of water
in the hours of no supply, which to the large extent may result from the negligence.
The sensitivity analysis suggests which input data should be verified with priority. The result show the size of
individual household tanks and the initial level when the supply begins have more impact on the overflow, than the
leakage percentage or per capita demand. Despite the fact that many assumptions were made, this analysis provides a
practical approach to measure the volume that might be spilled from household tanks, which seems to be the main
source of water wastage. The municipality would need to monitor and record individual characteristics of the
households’ storage facilities, in order to assess more accurately the extent of this problem. Also, the model should
be further calibrated by adequate choice of emitter coefficients.
Finally, the research points that the hydraulic modelling of distribution networks in tourist islands poses quite a
complex problem due to: (1) numerical instability caused by multiple tanks existing in the model, and (2) difficult
calibration from lots of unknown and inaccurate data needed to build a reliable model.
References
Ameyaw, E. E., Memon, F. A. and Bicik, J. (2013). Improving equity in intermittent water supply systems. Journal
of Water Supply: Research and Technology-AQUA, 62(8): 552-62.
Andey, S. P. and Kelkar, P. S. (2009). Influence of intermittent and continuous modes of water supply on domestic
water consumption. Water Resources Management, 23(12): 2555-66.
Cheung, P., Van Zyl, J. and Reis, L. (2005). Extension of EPANET for pressure driven demand modeling in water
distribution system. Computing and Control for the Water Industry, 1(1): 311-16.
Germanopoulos, G. (1985). A technical note on the inclusion of pressure dependent demand and leakage terms in
water supply network models. Civil Engineering Systems, 2(3): 171-79.
Gupta, R. and Bhave, P. R. (1996). Comparison of methods for predicting deficient-network performance. Journal of
Water Resources Planning and Management, 122(3): 214-17.
Hayuti, M. and Burrows, R., 2004. "Sequential solution seeking dda based hda (sss-dda/hda) approach." In Proc. of
Decision Support in the Water Industry under Conditions of Uncertainty-ACTUI 2004.
INEC, 2010. "Censo de población y vivienda del ecuador 2010." In Ecuador, Instituto Nacional de Estadísticas y
Censos.
Ingeduld, P., Svitak, Z., Pradhan, A. and Tarai, A., 2006. "Modelling intermittent water supply systems with
EPANET." In 8th Annual Water Distribution Systems Analysis Symposium, Cincinnati.
Martinez, F., Signes, M., Savall, R., Andrés, M., Ponz, R. and Conejos, P. (1999). Construction and use of dynamic
simulation model for the valencia metropolitan water supply and distribution network. Water Industry
Systems: Modeling and Optimization Applications, In: Savic, DA and Walters, GA. 1: 155-74.
Mena, C., Walsh, S., Pizzitutti, F., Reck, G., Rindfuss, R., Toral-Granda, V. D. O., Valle, C., Quiroga, D., García, J.,
Vasconez, L., Guevara, A., Sanchez, M., Frizelle, B. and Tippett, R. (2013). Determination of social,
environmental and economical relations which allow the development based on different processes of
modeling, potential scenarios of sustainability of the socio ecological system of the Galapagos Islands with
emphasis on the dynamic of the flux of tourist visitors. Ministry of Environment and Galapagos National
Park. 1: Galapagos.
Ozger, S. S. and Mays, L., 2003. "A semi-pressure-driven approach to reliability assessment of water distribution
networks." In Proceedings of the Thirtieth Congress.
Pathirana, A., 2010. "EPANET2 desktop application for pressure driven demand modeling." In In Water
Distribution Systems Analysis 2010. pp. 65-74.
Reyes, Trifunović, N., Sharma, S. and Kennedy, M. (2016). Data assessment for water demand and supply balance
on the island of santa cruz (galápagos Islands). Desalination and Water Treatment, 57(45): 21335-49.
Reyes, Trifunović, N., Sharma, S. and Kennedy, M. D. (2017a). Assessment of domestic consumption in intermittent
water supply networks: Case study of Puerto Ayora (Galápagos Islands). Journal of Water Supply:
Research and Technology-Aqua, 55(8): 673-83.
Reyes, Trifunovic, N., d’Ozouville, N., Sharma, S. and Kennedy, M. (2017b). Quantification of urban water demand
in the island of santa cruz (galápagos archipelago). Desalination and Water Treatment, 64(1): 1-11.
Reyes Pérez, M. F. (2017). Water supply and demand management in the galápagos: A case study of. CRC Press:
Santa Cruz Island.
Rossman, L. A. (2000). EPANET 2: Users manual. Available:
https://www.microimages.com/documentation/Tutorials/Epanet2UserManual.pdf
Seetharam, K. and Bridges, G., 2005. "Helping India achieve 24x7 water supply service by 2010." In Roundtable
discussion on private sector participation in water supply in India. pp. 15-16.
Soares, A. K., Reis, L. F. R. and Carrijo, I. B., 2003. "Head-driven simulation model (HDSM) for water distribution
system calibration. Advances in Water Supply Management." In Proceedings of the ccwi '03 conference,
london, 15-17 september 2003. pp. 197-207.
Tanyimboh, T., Tabesh, M. and Burrows, R. (2001). Appraisal of source head methods for calculating reliability of
water distribution networks. Journal of Water Resources Planning and Management, 127(4): 206-13.
11. International Journal of World Policy and Development Studies
81
Tanyimboh, T., Walters, G., Savic, D., Khoo, S. T. and King, R., 2004. "Availability of water in distribution
systems. In Decision support in the water industry under conditions of uncertainty." In Proceedings of the
2004 EPSRC ACTUI network international seminar. pp. 159-64.
Trifunović, N. and Abu-Madi, M. O. R., 1999. "Demand modelling of networks with individual storage." In In
WRPMD'99: Preparing for the 21st Century. pp. 1-10.
Vairavamoorthy, K., Gorantiwar, S. D. and Mohan, S. (2007). Intermittent water supply under water scarcity
situations. Water International, 32(1): 121-32.
Vairavamoorthy, K., Gorantiwar, S. D. and Pathirana, A. (2008). Managing urban water supplies in developing
countries–Climate change and water scarcity scenarios. Physics and Chemistry of the Earth, Parts A/B/C,
33(5): 330-39.