This document discusses the key biophysical characteristics of a watershed that impact its hydrology. It describes the watershed hydrological cycle, including inputs like precipitation, storages like surface water and groundwater, and outputs like evapotranspiration. It also discusses the geology, soil types, topography, and geomorphology of the watershed, explaining how each factor influences infiltration rates, runoff rates, erosion potential, and flooding. Topics like watershed size, shape, slope, and the permeability of underlying rock and soils are covered in relation to hydrological impacts.
This document presents an overview of water balance calculations. It defines water balance and its components such as precipitation, evapotranspiration, soil moisture, surplus and deficit. It describes different types of water balances including surface water, groundwater, soil water, lake water and oceanic water balances. The document discusses applications of water balance calculations and limitations. It concludes that water balance estimation is an important tool for assessing water resources and supporting water management decisions.
This study explains the use of remote sensing data for spatially distributed hydrological modeling using the MIKE-SHE software used in Tarim River Basin CHINA
Waterlogging refers to soil saturation from high water tables, preventing air and oxygen flow needed by crops. It is caused by over-irrigation, inadequate drainage, flooding, and high water tables during monsoons. Waterlogging can be permanent, periodic, or temporary, and often leads to soil salinization in irrigated areas due to prevented leaching of salts. Major waterlogged areas in Bangladesh include wetlands, floodplains, coastal areas, and areas with artificial irrigation. Waterlogging hampers soil microbial activity, reduces nutrient availability, increases soil pH, and favors weed growth. Reducing measures include dams, embankments, and bridges/culverts to restrict water flow.
Along with changes in temperature, climate change will bring changes in global rainfall amounts and distribution patterns. And since temperature and water are two factors that have a large influence on the processes that take place in soils, climate change will therefore cause changes in the world’s soils
Geographic information systems (GIS) are organized collections of computer hardware, software, and geographic data used to capture, store, update, manipulate, analyze, and display geographically referenced information. GIS provides spatial data depicted as points, lines, or polygons with attributes stored in tables, and can take data from various sources and integrate them into multiple layers for analysis. Common applications of GIS include agriculture, natural resource management, disaster management, and urban planning.
Hydrologic cycle and field water balance dathan cs
The document discusses the hydrologic cycle and field water balance. It provides details on:
1) The hydrologic cycle, which describes the circulation of water between the atmosphere, land, oceans and biosphere through processes like evaporation, condensation, precipitation, and runoff.
2) Components of the hydrologic cycle like green water, blue water, infiltration, recharge, and groundwater flow.
3) The field water balance accounts for all water inputs, outputs, and storage within a soil area over a period of time based on the law of conservation of mass. It considers precipitation, runoff, evapotranspiration, and changes in water storage.
This document presents an overview of water balance calculations. It defines water balance and its components such as precipitation, evapotranspiration, soil moisture, surplus and deficit. It describes different types of water balances including surface water, groundwater, soil water, lake water and oceanic water balances. The document discusses applications of water balance calculations and limitations. It concludes that water balance estimation is an important tool for assessing water resources and supporting water management decisions.
This study explains the use of remote sensing data for spatially distributed hydrological modeling using the MIKE-SHE software used in Tarim River Basin CHINA
Waterlogging refers to soil saturation from high water tables, preventing air and oxygen flow needed by crops. It is caused by over-irrigation, inadequate drainage, flooding, and high water tables during monsoons. Waterlogging can be permanent, periodic, or temporary, and often leads to soil salinization in irrigated areas due to prevented leaching of salts. Major waterlogged areas in Bangladesh include wetlands, floodplains, coastal areas, and areas with artificial irrigation. Waterlogging hampers soil microbial activity, reduces nutrient availability, increases soil pH, and favors weed growth. Reducing measures include dams, embankments, and bridges/culverts to restrict water flow.
Along with changes in temperature, climate change will bring changes in global rainfall amounts and distribution patterns. And since temperature and water are two factors that have a large influence on the processes that take place in soils, climate change will therefore cause changes in the world’s soils
Geographic information systems (GIS) are organized collections of computer hardware, software, and geographic data used to capture, store, update, manipulate, analyze, and display geographically referenced information. GIS provides spatial data depicted as points, lines, or polygons with attributes stored in tables, and can take data from various sources and integrate them into multiple layers for analysis. Common applications of GIS include agriculture, natural resource management, disaster management, and urban planning.
Hydrologic cycle and field water balance dathan cs
The document discusses the hydrologic cycle and field water balance. It provides details on:
1) The hydrologic cycle, which describes the circulation of water between the atmosphere, land, oceans and biosphere through processes like evaporation, condensation, precipitation, and runoff.
2) Components of the hydrologic cycle like green water, blue water, infiltration, recharge, and groundwater flow.
3) The field water balance accounts for all water inputs, outputs, and storage within a soil area over a period of time based on the law of conservation of mass. It considers precipitation, runoff, evapotranspiration, and changes in water storage.
Impact of Climate Change on Groundwater ResourcesC. P. Kumar
This document summarizes the impact of climate change on groundwater resources. It discusses how climate change can affect factors like precipitation, temperature, and evapotranspiration, which then impact groundwater recharge and levels. Higher temperatures and variability in rainfall from climate change could mean more fluctuations in groundwater levels and potential saline intrusion in coastal aquifers. Quantifying the full impact on groundwater requires downscaling climate models and coupling them with hydrological models to estimate changes in groundwater recharge over time. Key concerns are potential decreases in groundwater supplies and quality issues, as groundwater serves as a major global source of potable water.
This document summarizes Palestinian water resources, including surface water like the Jordan River, and groundwater. It discusses the Western, Eastern, and Northeastern groundwater basins in the West Bank, and the coastal aquifer in Gaza. It notes that while the Jordan River is the most important surface water, groundwater is the primary source due to rainfall fluctuations. It also outlines processes that contribute to salinization of Gaza's groundwater and discusses artificial groundwater recharge as a way to address saltwater intrusion and water shortages. The document provides definitions for key water-related terms in Palestinian law.
Introducing Groundwater Management PowerPoint Presentation Slides. Analyze information about water quality and underpin decisions about water resource management with this PPT slideshow. Demonstrate the process of planning, developing, and managing the optimum use of water by using this visually appealing PPT layout. The survey data for determining water quality can be easily presented by using our professionally designed water cycle management PowerPoint slideshow. Describe the natural processes and human processes that affect water quality. Understand sources of water pollution, natural and human processes affecting water quality by taking the advantage of this PPT slideshow. Provide data on the optimization of deterioration in water quality and pollutants that deteriorate the quality of water on a global scale with the help of our water quality management PowerPoint infographics. You can easily explain further topics like wastewater treatment process, wastewater reuse, global wastewater reuse by sector, etc. by downloading this ready-to-use PowerPoint slide deck. https://bit.ly/2RCTUun
The document defines and discusses several terms related to hydrology:
1. Potamology is the study of rivers, which examines rivers from five perspectives including the physics of running water and rivers as habitats for organic life.
2. Limnology is the study of biological, chemical, and physical features of lakes and other bodies of fresh water.
3. Cryology is the scientific study of ice, including areas like snow and ice mapping and classification.
The Physical Properties of the Soil
Inckuding,
1. Soil Texture
2. Soil Structure
3. Soil Color
4. Soil Density
5. Soil Porosity
6. Soil Consistence
7. Soil Temperature
River bank erosion, its migration, causesNazim Naeem
Riverbank Erosion is an endemic natural hazard in our country.
When rivers enter the mature, they become sluggish and
meander or braid. These oscillations cause extreme riverbank
erosion. It is a perennial problem in our country.
• It has been estimated that tens of thousands of people are
displaced annually by river erosion in Bangladesh, possibly up to
100,000. Many households are forced to move away from their
homesteads due to riverbank erosion and flood.
• As per different sources, 500 kilometres of riverbank face
severe problems related to erosion. The northwest part of the
country is particularly prone to riverbank erosion, which has
turned the region into an economically depressed area.
Iirs overview -Remote sensing and GIS application in Water Resources ManagementTushar Dholakia
Remote sensing and GIS application in Water Resources Management- By S.P. Aggarval spa@iirs.gov.in Indian Institute of Remote sensing ISRO, Department of space, Dehradun
Presented by IWMI's Lal Muthuwatta (Regional Researcher – Hydrological Modeling & Remote Sensing) to a group of European Union (EU) delegations in Asia at a discussion on 'Using research on agriculture climate and water to support sustainable food systems', held at IWMI Headquarters in Colombo, Sri Lanka, on June 8, 2016.
The document discusses infiltration, which is the process by which water enters soil. It defines infiltration as the rate at which soil can absorb rainfall or irrigation, measured in mm/hr or inches/hr. An infiltrometer is used to measure infiltration rates. The infiltration capacity depends on factors like the soil type and moisture level, with dry soil having a higher capacity than moist soil. Infiltration is important for understanding groundwater recharge and runoff. Other factors like vegetation cover, land use, temperature, and water quality can also impact infiltration rates.
The document summarizes the empirical USLE and RUSLE models for predicting long-term soil loss on fields. The USLE model, developed in 1978, estimates soil erosion based on 5 factors: rainfall erosivity, soil erodibility, slope length and steepness, cover management, and conservation practices. The RUSLE revision in 1992 incorporated new research using computers and GIS to update factors and the calculation algorithm. Both models assist with soil conservation planning but have limitations as they only estimate rill and sheet erosion, not deposition or gully erosion.
CLIMATE change affects the components of water cycle such as evaporation, precipitation and evapotranspiration and thus results in large-scale alteration in water present in glaciers, rivers, lakes, oceans, etc. The effects of cli-mate change on subsurface water relates to the changes in its recharge and discharge rates plus changes in quantity and quality of water in aquifers. Climate change refers to the long-term changes in the components of climate such as temperature, precipitation, evapotranspiration, etc. The major cause of climate change is the rising level of greenhouse gases (GHGs) in the atmosphere such as CO2, CH4, N2O, water vapour, ozone and chlorofluorocarbon. These GHGs absorb 95% of the longwave back radiations emitted from the surface, thus making the Earth warmer. Except CO2, the effects of other GHGs are minor because of their low concentration and also because of low residence times (e.g. water vapour and methane). The rise in CO2 level causing global warming was first proposed by Svante Arrhenius, a Swedish scientist in 1896 and now it is a widely accepted fact that the concentration of CO2 is the primary regulator of temperature on the Earth and leads to global warming.
Randy Lehr (Northland College), presented at the Adapting Forested Watersheds to Climate Change Workshop, at The Waters, Minocqua, WI on March 15-16, 2017. The workshop was hosted by the Northern Institute of Applied Climate Science (NIACS), USDA Climate Hubs, and the Wisconsin Initiative on Climate Change Impacts (WICCI).
A drainage basin is defined as an area of land drained by a river and its tributaries, with watersheds separating adjacent basins, and any precipitation falling beyond a watershed will drain into a neighboring basin; the drainage basin hydrological cycle involves inputs like precipitation, storage in surface waters and groundwater, transfer through runoff, groundwater and subsurface flow, and outputs through rivers draining into seas and losses from evapotranspiration.
The document describes the components and processes involved in the drainage basin hydrological cycle, including inputs, storage, transfer, and outputs of water within a bounded drainage basin area.
A drainage basin is an area of land where surface water converges to a single point, usually the exit of the basin. There are several types of drainage systems that form depending on the terrain and geology, including dendritic, parallel, rectangular, trellis, radial, and annular systems. Stream ordering schemes classify streams in a hierarchy based on how they join together. Quantitative analysis of drainage basins uses metrics like bifurcation ratio, length ratio, and drainage density to characterize aspects of the basin.
The document discusses watershed management and deterioration. It notes that watershed deterioration occurs due to faulty management practices related to agriculture, forestry, mining, construction, and apathy. This results in less production, increased erosion, reservoir siltation, lowered water tables, and poverty. Watershed development techniques aim to address this through soil and water conservation methods tailored for different land types, like contour trenches, bench terracing, check dams, plantation, and agroforestry. The goal is integrated management of human resources, land, water, crops, livestock, and other components for sustainable watershed development.
The document summarizes a study that used the WEPP (Water Erosion Prediction Project) model to simulate runoff and sediment yield from a hilly watershed in the eastern Himalayas region of India. The study involved calibrating and validating the WEPP model using data from 2003-2004, which achieved a model efficiency greater than 0.87. The model successfully simulated runoff and sediment yield in the high rainfall and steep slope conditions. Simulation results indicated that certain crops and reduced tillage practices could significantly reduce sediment yield, and installing porous rock fill check dams could also control sediment yield.
The document discusses hydraulic conductivity, which measures the ability of a material like soil or rock to transmit fluids through pores and fractures under an applied hydraulic gradient. It describes hydraulic conductivity as being important for calculating groundwater movement rates and outlines experimental and empirical methods for determining it in the field or laboratory, such as constant head tests, falling head tests, or correlations with soil properties. Hydraulic conductivity is the constant in Darcy's Law and is defined as the volume of water that will move through a porous medium per unit time under a unit hydraulic gradient through a unit area measured perpendicular to flow.
Groundwater occurs beneath the Earth's surface in pore spaces and fractures in rocks and sediments. It originates from rainfall and snowmelt percolating into the ground. Groundwater is found everywhere but is usually within 750 meters of the surface. It makes up about 1% of the total water on Earth but 35 times the amount of water in streams and lakes. Groundwater flows through the hydrologic cycle, entering the ground as precipitation and eventually emerging in streams, lakes, or oceans.
WATERSHED NOTES IN BOTH HYDROLOGY AND GEOMORPHOLOGY COURSES.pptxFormulaMw
This document discusses different types of watersheds based on size, land use, and geography. It describes:
1) Watersheds are classified by size as small (<250 km2), medium (250-2500 km2), or large (>2500 km2). Small watersheds have more land phase runoff while large watersheds have more developed channel networks.
2) Watersheds can also be classified by land use as urban, agricultural, forested, mountainous, desert, coastal, or mixed. Each land use type influences the watershed's hydrology differently.
3) Additional factors like geography, vegetation, soil type, and rainfall patterns determine a watershed's runoff and
Impact of Climate Change on Groundwater ResourcesC. P. Kumar
This document summarizes the impact of climate change on groundwater resources. It discusses how climate change can affect factors like precipitation, temperature, and evapotranspiration, which then impact groundwater recharge and levels. Higher temperatures and variability in rainfall from climate change could mean more fluctuations in groundwater levels and potential saline intrusion in coastal aquifers. Quantifying the full impact on groundwater requires downscaling climate models and coupling them with hydrological models to estimate changes in groundwater recharge over time. Key concerns are potential decreases in groundwater supplies and quality issues, as groundwater serves as a major global source of potable water.
This document summarizes Palestinian water resources, including surface water like the Jordan River, and groundwater. It discusses the Western, Eastern, and Northeastern groundwater basins in the West Bank, and the coastal aquifer in Gaza. It notes that while the Jordan River is the most important surface water, groundwater is the primary source due to rainfall fluctuations. It also outlines processes that contribute to salinization of Gaza's groundwater and discusses artificial groundwater recharge as a way to address saltwater intrusion and water shortages. The document provides definitions for key water-related terms in Palestinian law.
Introducing Groundwater Management PowerPoint Presentation Slides. Analyze information about water quality and underpin decisions about water resource management with this PPT slideshow. Demonstrate the process of planning, developing, and managing the optimum use of water by using this visually appealing PPT layout. The survey data for determining water quality can be easily presented by using our professionally designed water cycle management PowerPoint slideshow. Describe the natural processes and human processes that affect water quality. Understand sources of water pollution, natural and human processes affecting water quality by taking the advantage of this PPT slideshow. Provide data on the optimization of deterioration in water quality and pollutants that deteriorate the quality of water on a global scale with the help of our water quality management PowerPoint infographics. You can easily explain further topics like wastewater treatment process, wastewater reuse, global wastewater reuse by sector, etc. by downloading this ready-to-use PowerPoint slide deck. https://bit.ly/2RCTUun
The document defines and discusses several terms related to hydrology:
1. Potamology is the study of rivers, which examines rivers from five perspectives including the physics of running water and rivers as habitats for organic life.
2. Limnology is the study of biological, chemical, and physical features of lakes and other bodies of fresh water.
3. Cryology is the scientific study of ice, including areas like snow and ice mapping and classification.
The Physical Properties of the Soil
Inckuding,
1. Soil Texture
2. Soil Structure
3. Soil Color
4. Soil Density
5. Soil Porosity
6. Soil Consistence
7. Soil Temperature
River bank erosion, its migration, causesNazim Naeem
Riverbank Erosion is an endemic natural hazard in our country.
When rivers enter the mature, they become sluggish and
meander or braid. These oscillations cause extreme riverbank
erosion. It is a perennial problem in our country.
• It has been estimated that tens of thousands of people are
displaced annually by river erosion in Bangladesh, possibly up to
100,000. Many households are forced to move away from their
homesteads due to riverbank erosion and flood.
• As per different sources, 500 kilometres of riverbank face
severe problems related to erosion. The northwest part of the
country is particularly prone to riverbank erosion, which has
turned the region into an economically depressed area.
Iirs overview -Remote sensing and GIS application in Water Resources ManagementTushar Dholakia
Remote sensing and GIS application in Water Resources Management- By S.P. Aggarval spa@iirs.gov.in Indian Institute of Remote sensing ISRO, Department of space, Dehradun
Presented by IWMI's Lal Muthuwatta (Regional Researcher – Hydrological Modeling & Remote Sensing) to a group of European Union (EU) delegations in Asia at a discussion on 'Using research on agriculture climate and water to support sustainable food systems', held at IWMI Headquarters in Colombo, Sri Lanka, on June 8, 2016.
The document discusses infiltration, which is the process by which water enters soil. It defines infiltration as the rate at which soil can absorb rainfall or irrigation, measured in mm/hr or inches/hr. An infiltrometer is used to measure infiltration rates. The infiltration capacity depends on factors like the soil type and moisture level, with dry soil having a higher capacity than moist soil. Infiltration is important for understanding groundwater recharge and runoff. Other factors like vegetation cover, land use, temperature, and water quality can also impact infiltration rates.
The document summarizes the empirical USLE and RUSLE models for predicting long-term soil loss on fields. The USLE model, developed in 1978, estimates soil erosion based on 5 factors: rainfall erosivity, soil erodibility, slope length and steepness, cover management, and conservation practices. The RUSLE revision in 1992 incorporated new research using computers and GIS to update factors and the calculation algorithm. Both models assist with soil conservation planning but have limitations as they only estimate rill and sheet erosion, not deposition or gully erosion.
CLIMATE change affects the components of water cycle such as evaporation, precipitation and evapotranspiration and thus results in large-scale alteration in water present in glaciers, rivers, lakes, oceans, etc. The effects of cli-mate change on subsurface water relates to the changes in its recharge and discharge rates plus changes in quantity and quality of water in aquifers. Climate change refers to the long-term changes in the components of climate such as temperature, precipitation, evapotranspiration, etc. The major cause of climate change is the rising level of greenhouse gases (GHGs) in the atmosphere such as CO2, CH4, N2O, water vapour, ozone and chlorofluorocarbon. These GHGs absorb 95% of the longwave back radiations emitted from the surface, thus making the Earth warmer. Except CO2, the effects of other GHGs are minor because of their low concentration and also because of low residence times (e.g. water vapour and methane). The rise in CO2 level causing global warming was first proposed by Svante Arrhenius, a Swedish scientist in 1896 and now it is a widely accepted fact that the concentration of CO2 is the primary regulator of temperature on the Earth and leads to global warming.
Randy Lehr (Northland College), presented at the Adapting Forested Watersheds to Climate Change Workshop, at The Waters, Minocqua, WI on March 15-16, 2017. The workshop was hosted by the Northern Institute of Applied Climate Science (NIACS), USDA Climate Hubs, and the Wisconsin Initiative on Climate Change Impacts (WICCI).
A drainage basin is defined as an area of land drained by a river and its tributaries, with watersheds separating adjacent basins, and any precipitation falling beyond a watershed will drain into a neighboring basin; the drainage basin hydrological cycle involves inputs like precipitation, storage in surface waters and groundwater, transfer through runoff, groundwater and subsurface flow, and outputs through rivers draining into seas and losses from evapotranspiration.
The document describes the components and processes involved in the drainage basin hydrological cycle, including inputs, storage, transfer, and outputs of water within a bounded drainage basin area.
A drainage basin is an area of land where surface water converges to a single point, usually the exit of the basin. There are several types of drainage systems that form depending on the terrain and geology, including dendritic, parallel, rectangular, trellis, radial, and annular systems. Stream ordering schemes classify streams in a hierarchy based on how they join together. Quantitative analysis of drainage basins uses metrics like bifurcation ratio, length ratio, and drainage density to characterize aspects of the basin.
The document discusses watershed management and deterioration. It notes that watershed deterioration occurs due to faulty management practices related to agriculture, forestry, mining, construction, and apathy. This results in less production, increased erosion, reservoir siltation, lowered water tables, and poverty. Watershed development techniques aim to address this through soil and water conservation methods tailored for different land types, like contour trenches, bench terracing, check dams, plantation, and agroforestry. The goal is integrated management of human resources, land, water, crops, livestock, and other components for sustainable watershed development.
The document summarizes a study that used the WEPP (Water Erosion Prediction Project) model to simulate runoff and sediment yield from a hilly watershed in the eastern Himalayas region of India. The study involved calibrating and validating the WEPP model using data from 2003-2004, which achieved a model efficiency greater than 0.87. The model successfully simulated runoff and sediment yield in the high rainfall and steep slope conditions. Simulation results indicated that certain crops and reduced tillage practices could significantly reduce sediment yield, and installing porous rock fill check dams could also control sediment yield.
The document discusses hydraulic conductivity, which measures the ability of a material like soil or rock to transmit fluids through pores and fractures under an applied hydraulic gradient. It describes hydraulic conductivity as being important for calculating groundwater movement rates and outlines experimental and empirical methods for determining it in the field or laboratory, such as constant head tests, falling head tests, or correlations with soil properties. Hydraulic conductivity is the constant in Darcy's Law and is defined as the volume of water that will move through a porous medium per unit time under a unit hydraulic gradient through a unit area measured perpendicular to flow.
Groundwater occurs beneath the Earth's surface in pore spaces and fractures in rocks and sediments. It originates from rainfall and snowmelt percolating into the ground. Groundwater is found everywhere but is usually within 750 meters of the surface. It makes up about 1% of the total water on Earth but 35 times the amount of water in streams and lakes. Groundwater flows through the hydrologic cycle, entering the ground as precipitation and eventually emerging in streams, lakes, or oceans.
WATERSHED NOTES IN BOTH HYDROLOGY AND GEOMORPHOLOGY COURSES.pptxFormulaMw
This document discusses different types of watersheds based on size, land use, and geography. It describes:
1) Watersheds are classified by size as small (<250 km2), medium (250-2500 km2), or large (>2500 km2). Small watersheds have more land phase runoff while large watersheds have more developed channel networks.
2) Watersheds can also be classified by land use as urban, agricultural, forested, mountainous, desert, coastal, or mixed. Each land use type influences the watershed's hydrology differently.
3) Additional factors like geography, vegetation, soil type, and rainfall patterns determine a watershed's runoff and
Groundwater originates as rainfall or snowmelt that seeps into the ground and fills pore spaces and fractures in rocks and sediments below the Earth's surface. It makes up about 1% of the water on Earth but over 35 times as much water as is contained in all lakes and streams. Groundwater occurs nearly everywhere and generally to depths less than around 750 meters. The global volume of groundwater is equivalent to a 55-meter thick layer spread over the entire planet. The occurrence and flow of groundwater is influenced by factors such as topography, climate, geology, and the properties of underground materials. There are four main sources of groundwater: connate water trapped during rock formation, rainfall, irrigation water, and tidal
Hydrology and irrigation engineering cel 303Gaurav Mittal
This document summarizes information about infiltration, including definitions of key terms, factors that affect infiltration, and the infiltration capacity curve. It defines infiltration as the process by which water enters the soil surface and moves downward towards the water table. Key terms discussed include infiltration capacity, infiltration rate, field capacity, and equivalent moisture. Factors that influence infiltration include soil texture, crusting, compaction, organic matter, and pores. The infiltration capacity curve illustrates the relationship between infiltration rate and time during rainfall.
It includes the definition, properties, classification of groundwater with appropriate examples and figures in details. It also deals about the formation of groundwater. The properties of aquifers (all of 7) are described here in details with figures and mathematical terms.
What is the river discharge and what factorsMischa Knight
The document discusses factors that affect river discharge. It explains that river discharge is calculated based on the cross-sectional area of the river channel and flow velocity. Physical factors like rock type, drainage basin size and relief, and vegetation can impact discharge by affecting runoff and flow speed. Human activities such as urbanization and deforestation can also impact discharge by increasing runoff. Flood hydrographs illustrate how discharge changes during rain events, with peak discharge occurring after a lag time determined by drainage basin characteristics. Case studies can show how changes in discharge impact the drainage basin over time.
This document discusses groundwater concepts including:
- Groundwater occurs below the earth's surface and its movement is controlled by the porosity and permeability of geological materials.
- Aquifers are geological formations that yield significant water quantities while aquitards impede groundwater movement.
- The water table delineates the saturated and unsaturated zones. It fluctuates seasonally and due to pumping which causes cones of depression.
- Groundwater flow depends on factors like hydraulic gradients, bedding planes, faults and the permeability of geological materials.
This document discusses soil erosion, its types, causes, and impacts. There are two major types of erosion: geological (natural) erosion and accelerated erosion caused by human activities. Water erosion is caused by raindrop impact and flowing water, detaching and transporting soil particles. It occurs as sheet, rill, gully, ravine, landslide, and stream bank erosion. Wind erosion lifts and transports detached particles through saltation, surface creep, and suspension. Climate, topography, vegetation, soil properties, and human activities influence erosion rates. The Universal Soil Loss Equation is used to estimate water erosion.
This document provides an overview of ground water hydrology. It defines key terms like aquifers, aquitards, the water table, porosity, permeability and discusses the movement and storage of groundwater. It explains that groundwater is an important source of water, especially in arid areas, and outlines the water balance concept and different zones of subsurface water like the saturated and aeration zones.
Hydrology and Fluvial Geo morphology for CAMBRIDGE AS level Yonas Gemeda
This power point lesson describes about the hydrology and rivers work in detail with different tools, which is more important for students and candidates of Cambridge Examination at AS level.
Soil & water conservation.pptx for agricultural departmentsharanjain0
Soil erosion is the removal and transportation of soil from its original location by water, wind, or other forces. There are two main types of soil erosion: geological erosion which occurs naturally under vegetation cover; and accelerated erosion which occurs at a much faster rate when vegetation is removed and land is cultivated. Factors like deforestation, overgrazing, and poor agricultural practices can lead to accelerated water and wind erosion. Water erosion specifically occurs through raindrop splash, sheet wash, rill formation, gullying, and stream/river bank erosion. The universal soil loss equation is commonly used to estimate average annual soil loss. Unchecked erosion has negative environmental and economic impacts through loss of fertile topsoil and siltation of
CAMBRIDGE GEOGRAPHY AS - HYDROLOGY AND FLUVIAL GEOMORPHOLOGY; 1.1. DRAINAGE B...George Dumitrache
Introductory presentation of the drainage basin systems in the first chapter of Hydrology and Fluvial Geomorphology, suitable for AS students, consisting in the following: the global hydrological cycle, store, flows, the drainage systems, precipitation, evapotranspiration, interception, infiltration, percolation, drainage patterns, the water balance.
paper about the underground water and its geotechnical problems and how to control it
This is a large and complex topic and I have to focus on some key points that you need it to finish the project of the tunneling subject that you're working on it
The presentation includes the following subtopics:
*FLUID STORAGE AND MOBILITY: POROSITY AND PERMEABILITY
* FLUID STORAGE AND MOBILITY: POROSITY AND PERMEABILITY
*SUBSURFACE WATERS
*AQUIFER GEOMETRY AND GROUNDWATER FLOW
*DARCY’S LAW AND GROUNDWATER FLOW
*CONSEQUENCES OF GROUNDWATER WITHDRAWAL
*OTHER IMPACTS OF URBANIZATION ON GROUNDWATER SYSTEMS
*OTHER FEATURES INVOLVING SUBSURFACE WATER
*WATER QUALITY
*EXTENDING THE WATER SUPPLY
The document discusses various topics related to hydrologic cycles and groundwater including:
1) The water cycle is driven by energy from the sun and involves evaporation, transpiration, condensation, precipitation, and runoff.
2) Groundwater occurs below the ground surface in voids and fractures in rocks and soil based on porosity and permeability.
3) Aquifers are underground areas that store and transmit groundwater while aquicludes and aquitards have low permeability and transmit water slowly or not at all.
4) Different rock types like sedimentary, igneous, and metamorphic rocks can serve as aquifers depending on their porosity and permeability.
This document discusses groundwater and aquifers. It defines groundwater as water located below the earth's surface in spaces between rock particles and fractures. Precipitation infiltrates through the unsaturated zone and collects in the saturated zone below. The saturated zone contains groundwater, which can be extracted via wells. Groundwater flow is described by Darcy's Law, with velocity proportional to hydraulic gradient. Groundwater generally flows from areas of high elevation to low elevation, following the slope of the water table. The document also defines different types of aquifers and their characteristics, including unconfined, confined, perched, and artesian aquifers. Wells can tap unconfined or confined groundwater sources.
This document discusses hydrogeology, which is the study of groundwater. It begins by explaining the hydrologic cycle, in which water evaporates from bodies of water and transpirates from plants, condenses into clouds and precipitates back to the ground as rain or snow. Some precipitation infiltrates into the ground to become groundwater. The document then discusses groundwater occurrence, movement through aquifers, and factors that influence it like porosity, permeability and lithology. Finally, it describes the vertical distribution of groundwater into the unsaturated zone above the water table and saturated zone below it.
This document discusses groundwater, including:
- Groundwater is water found beneath the Earth's surface, filling spaces in rock and sediment. It is a major source of water supply.
- Groundwater originates from precipitation that infiltrates underground. It moves through the hydrologic cycle and is stored in aquifers.
- Aquifers are permeable rock formations that can supply significant water to wells and springs. Properties like porosity and permeability determine how much water rock can hold and transmit.
Similar to Chapter 2 (Watershed Characteristics).pptx (20)
This document discusses key concepts in statistical analysis, including parameters, statistics, and their uses. It provides examples to distinguish between population parameters and sample statistics. Parameters represent entire populations and are studied using all data, while statistics represent samples and are used to estimate parameters. The document also discusses defining problems, data collection methods like census and sampling, and the four basic steps of statistical data analysis: defining the problem, collecting data, analyzing data, and reporting results.
Rapid population growth is occurring due to higher birth rates and lower mortality rates. The main causes of population growth are the decline in death rates due to better medical facilities, technological advancements prolonging lifespans, and immigration. The effects of rapid population growth include depletion of natural resources, degradation of the environment, rise in unemployment, high living costs, and faster climate change. Scientific solutions to control population growth involve increasing education levels, especially for girls, raising awareness of family planning methods through social marketing programs, and educating people about the impacts of overpopulation.
1) The document discusses sustainable livelihoods and food security, outlining indicators of livelihoods and major theories around food availability decline and food security/insecurity.
2) It summarizes Malthusian and neo-Malthusian perspectives on population growth outstripping food production as well as Easter Boserup's optimistic view that population growth spurs agricultural innovation.
3) Natural disasters like drought and flooding are described as climatic theories for food shortage, while Adam Smith viewed anything disrupting food production as a cause of famine.
The document discusses major development issues and strategies to address poverty. It identifies the top three development issues as poverty, unemployment, and inequality. It defines poverty as individuals whose incomes fall below a certain threshold or poverty line, lacking access to basic needs. Poverty can be measured as either absolute, not having enough to survive, or relative, having less than others. Deprivation of assets and capabilities is another way to measure poverty. Institutional and indigenous/community-based strategies are also discussed as approaches to address development issues and poverty.
This document discusses vulnerability and resilience in the context of livelihoods and food security. It defines vulnerability as the degree to which people or assets are exposed to harm from hazards, which is determined by their location. Resilience refers to the ability to recover from hardship. Several factors influence livelihoods, including hazards, poverty, environmental degradation, urbanization, and climate change. Hazards disproportionately impact the poor, who often live in more hazardous areas with less capacity to cope. The document analyzes how different elements like gender, age, assets and facilities are vulnerable to various hazards.
There is a two-way relationship between climate change and environmental change. Climate change can drive environmental changes through factors like changes in temperature and precipitation. However, environmental changes like pollution can also trigger further climate change. The chapter discusses both natural and human causes of climate change such as variations in Earth's orbit, volcanic eruptions, and increased greenhouse gas emissions from human activities. It also describes how climate change impacts the atmosphere by increasing global surface temperatures and temperature variations around the world.
1. The document discusses ecological models and invasive species. It provides information on the desert locust and water hyacinth as examples of invasive species. Ecological models recognize multiple levels of influence on health and behavior. Invasive species can harm ecosystems and economies. The desert locust causes agricultural damage and famine while water hyacinth clogs waterways. Controlling invasive species involves mechanical, chemical and biological methods.
Chapter 4 (Climate Change and Human Health).pptxhuseinmuzayen
This document discusses how climate change affects human health in various ways. It outlines how increases in temperature, changes in air quality, and more extreme weather events can negatively impact human health by exacerbating existing health issues like respiratory and cardiovascular disease and introducing new health threats. Certain populations, like the elderly, children, and economically disadvantaged groups, are especially vulnerable. The document provides examples of how climate change is already increasing health risks in the United States from issues like heat waves, poor air quality, wildfires, and altered allergen exposure.
Ecological models allow exploration of alternative policies and their environmental consequences. They recognize multiple levels of influence on health, from intrapersonal to policy levels. The ecological model framework identifies reasons for public health problems and plans interventions addressing factors at intrapersonal, interpersonal, institutional, community, and policy levels. Ecological models integrate behavioral and environmental changes, and consider interactions between personal and environmental influences on health.
This document summarizes how climate change affects human health in various ways. It discusses how increases in temperature, changes in air quality, and more extreme weather events can negatively impact human health by exacerbating illnesses like heat stroke, respiratory diseases, and increasing risks from events like wildfires. Certain populations are especially vulnerable. The health impacts are projected to intensify over the century as the climate continues changing unless action is taken to reduce emissions and adapt to the changing conditions.
This document discusses payment for ecosystem services (PES). It begins by defining ecosystem services and the four main categories. It then discusses the concept of valuing nature and complexity in determining ecosystem services. It questions whether the value of services like water filtration changes if alternatives become cheaper. It provides estimates of billions of dollars spent through PES programs and biodiversity funding. It concludes that while PES has limited impact currently, it could evolve but decisions should focus on conservation, not cost-benefit analysis, and protect nature overall rather than short-term gains. Caution is needed to avoid trading long-term success for marginal short gains through ecosystem services.
This document discusses payment for ecosystem services (PES). It begins by defining ecosystem services and outlining the four main categories. It then considers whether directly paying for ecosystem services is a useful conservation tool. While PES programs have channeled over $6.5 billion annually, the concept's impact is currently limited. PES has potential if decision-making prioritizes nature conservation rather than cost-benefit analysis. Overall, ecosystem services can support conservation goals but the main focus should be protecting nature itself.
The document discusses environmental change and its relationship to disasters and risk. It defines key terms like environment, environmental change, disaster, environmental disaster, and risk. It describes the major systems that make up the environment - the geosphere, biosphere, lithosphere, hydrosphere, atmosphere, and anthroposphere. It outlines the main natural and human-induced causes of environmental change, including population growth, economic growth, technology, political systems, and human behavior/attitudes. The consequences of environmental change discussed include increased heat, drought, wildfires, declining water supplies, reduced crop yields, and various health impacts.
Evolving Lifecycles with High Resolution Site Characterization (HRSC) and 3-D...Joshua Orris
The incorporation of a 3DCSM and completion of HRSC provided a tool for enhanced, data-driven, decisions to support a change in remediation closure strategies. Currently, an approved pilot study has been obtained to shut-down the remediation systems (ISCO, P&T) and conduct a hydraulic study under non-pumping conditions. A separate micro-biological bench scale treatability study was competed that yielded positive results for an emerging innovative technology. As a result, a field pilot study has commenced with results expected in nine-twelve months. With the results of the hydraulic study, field pilot studies and an updated risk assessment leading site monitoring optimization cost lifecycle savings upwards of $15MM towards an alternatively evolved best available technology remediation closure strategy.
Improving the viability of probiotics by encapsulation methods for developmen...Open Access Research Paper
The popularity of functional foods among scientists and common people has been increasing day by day. Awareness and modernization make the consumer think better regarding food and nutrition. Now a day’s individual knows very well about the relation between food consumption and disease prevalence. Humans have a diversity of microbes in the gut that together form the gut microflora. Probiotics are the health-promoting live microbial cells improve host health through gut and brain connection and fighting against harmful bacteria. Bifidobacterium and Lactobacillus are the two bacterial genera which are considered to be probiotic. These good bacteria are facing challenges of viability. There are so many factors such as sensitivity to heat, pH, acidity, osmotic effect, mechanical shear, chemical components, freezing and storage time as well which affects the viability of probiotics in the dairy food matrix as well as in the gut. Multiple efforts have been done in the past and ongoing in present for these beneficial microbial population stability until their destination in the gut. One of a useful technique known as microencapsulation makes the probiotic effective in the diversified conditions and maintain these microbe’s community to the optimum level for achieving targeted benefits. Dairy products are found to be an ideal vehicle for probiotic incorporation. It has been seen that the encapsulated microbial cells show higher viability than the free cells in different processing and storage conditions as well as against bile salts in the gut. They make the food functional when incorporated, without affecting the product sensory characteristics.
Epcon is One of the World's leading Manufacturing Companies.EpconLP
Epcon is One of the World's leading Manufacturing Companies. With over 4000 installations worldwide, EPCON has been pioneering new techniques since 1977 that have become industry standards now. Founded in 1977, Epcon has grown from a one-man operation to a global leader in developing and manufacturing innovative air pollution control technology and industrial heating equipment.
Climate Change All over the World .pptxsairaanwer024
Climate change refers to significant and lasting changes in the average weather patterns over periods ranging from decades to millions of years. It encompasses both global warming driven by human emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. While climate change is a natural phenomenon, human activities, particularly since the Industrial Revolution, have accelerated its pace and intensity
Kinetic studies on malachite green dye adsorption from aqueous solutions by A...Open Access Research Paper
Water polluted by dyestuffs compounds is a global threat to health and the environment; accordingly, we prepared a green novel sorbent chemical and Physical system from an algae, chitosan and chitosan nanoparticle and impregnated with algae with chitosan nanocomposite for the sorption of Malachite green dye from water. The algae with chitosan nanocomposite by a simple method and used as a recyclable and effective adsorbent for the removal of malachite green dye from aqueous solutions. Algae, chitosan, chitosan nanoparticle and algae with chitosan nanocomposite were characterized using different physicochemical methods. The functional groups and chemical compounds found in algae, chitosan, chitosan algae, chitosan nanoparticle, and chitosan nanoparticle with algae were identified using FTIR, SEM, and TGADTA/DTG techniques. The optimal adsorption conditions, different dosages, pH and Temperature the amount of algae with chitosan nanocomposite were determined. At optimized conditions and the batch equilibrium studies more than 99% of the dye was removed. The adsorption process data matched well kinetics showed that the reaction order for dye varied with pseudo-first order and pseudo-second order. Furthermore, the maximum adsorption capacity of the algae with chitosan nanocomposite toward malachite green dye reached as high as 15.5mg/g, respectively. Finally, multiple times reusing of algae with chitosan nanocomposite and removing dye from a real wastewater has made it a promising and attractive option for further practical applications.
ENVIRONMENT~ Renewable Energy Sources and their future prospects.tiwarimanvi3129
This presentation is for us to know that how our Environment need Attention for protection of our natural resources which are depleted day by day that's why we need to take time and shift our attention to renewable energy sources instead of non-renewable sources which are better and Eco-friendly for our environment. these renewable energy sources are so helpful for our planet and for every living organism which depends on environment.
Microbial characterisation and identification, and potability of River Kuywa ...Open Access Research Paper
Water contamination is one of the major causes of water borne diseases worldwide. In Kenya, approximately 43% of people lack access to potable water due to human contamination. River Kuywa water is currently experiencing contamination due to human activities. Its water is widely used for domestic, agricultural, industrial and recreational purposes. This study aimed at characterizing bacteria and fungi in river Kuywa water. Water samples were randomly collected from four sites of the river: site A (Matisi), site B (Ngwelo), site C (Nzoia water pump) and site D (Chalicha), during the dry season (January-March 2018) and wet season (April-July 2018) and were transported to Maseno University Microbiology and plant pathology laboratory for analysis. The characterization and identification of bacteria and fungi were carried out using standard microbiological techniques. Nine bacterial genera and three fungi were identified from Kuywa river water. Clostridium spp., Staphylococcus spp., Enterobacter spp., Streptococcus spp., E. coli, Klebsiella spp., Shigella spp., Proteus spp. and Salmonella spp. Fungi were Fusarium oxysporum, Aspergillus flavus complex and Penicillium species. Wet season recorded highest bacterial and fungal counts (6.61-7.66 and 3.83-6.75cfu/ml) respectively. The results indicated that the river Kuywa water is polluted and therefore unsafe for human consumption before treatment. It is therefore recommended that the communities to ensure that they boil water especially for drinking.
Presented by The Global Peatlands Assessment: Mapping, Policy, and Action at GLF Peatlands 2024 - The Global Peatlands Assessment: Mapping, Policy, and Action
Recycling and Disposal on SWM Raymond Einyu pptxRayLetai1
Increasing urbanization, rural–urban migration, rising standards of living, and rapid development associated with population growth have resulted in increased solid waste generation by industrial, domestic and other activities in Nairobi City. It has been noted in other contexts too that increasing population, changing consumption patterns, economic development, changing income, urbanization and industrialization all contribute to the increased generation of waste.
With the increasing urban population in Kenya, which is estimated to be growing at a rate higher than that of the country’s general population, waste generation and management is already a major challenge. The industrialization and urbanization process in the country, dominated by one major city – Nairobi, which has around four times the population of the next largest urban centre (Mombasa) – has witnessed an exponential increase in the generation of solid waste. It is projected that by 2030, about 50 per cent of the Kenyan population will be urban.
Aim:
A healthy, safe, secure and sustainable solid waste management system fit for a world – class city.
Improve and protect the public health of Nairobi residents and visitors.
Ecological health, diversity and productivity and maximize resource recovery through the participatory approach.
Goals:
Build awareness and capacity for source separation as essential components of sustainable waste management.
Build new environmentally sound infrastructure and systems for safe disposal of residual waste and replacing current dumpsites which should be commissioned.
Current solid waste management situation:
The status.
Solid waste generation rate is at 2240 tones / day
collection efficiently is at about 50%.
Actors i.e. city authorities, CBO’s , private firms and self-disposal
Current SWM Situation in Nairobi City:
Solid waste generation – collection – dumping
Good Practices:
• Separation – recycling – marketing.
• Open dumpsite dandora dump site through public education on source separation of waste, of which the situation can be reversed.
• Nairobi is one of the C40 cities in this respect , various actors in the solid waste management space have adopted a variety of technologies to reduce short lived climate pollutants including source separation , recycling , marketing of the recycled products.
• Through the network, it should expect to benefit from expertise of the different actors in the network in terms of applicable technologies and practices in reducing the short-lived climate pollutants.
Good practices:
Despite the dismal collection of solid waste in Nairobi city, there are practices and activities of informal actors (CBOs, CBO-SACCOs and yard shop operators) and other formal industrial actors on solid waste collection, recycling and waste reduction.
Practices and activities of these actor groups are viewed as innovations with the potential to change the way solid waste is handled.
CHALLENGES:
• Resource Allocation.
2. CHAPTER 2: ANALYSIS OF WATERSHED
CHARACTERISTICS
2
Characteristics of a watershed are broadly
divided into:
i. Biophysical characteristics
ii. Socioeconomic characteristics
2.1 Bio-physical Characteristics of a Watershed
These include:
Watershed hydrological cycle
Geology
Soil characteristics
Topography
Geomorphology
Climate
land use/land cover
3. A. Watershed Hydrological Cycle
• The watershed hydrological cycle is an open
system which has a range of inputs, storages,
transfers/flows, and outputs.
• Energy from the sun and precipitation
(including rain and snow) enter the system and
water leaves it.
• The figure below illustrates the inputs, storages,
transfers, and outputs of the watershed
hydrological cycle.
4.
5. a. Inputs – water coming into the system
• Precipitation – all forms of moisture that reach
the Earth’s surface e.g. rain, snow, sleet and hail.
b. Storage – water stored in the system
• Interception – this is when precipitation lands on
buildings, vegetation and concrete before it
reaches the soil.
• Interception storage is only temporary as it is
often quickly evaporated.
• Vegetation storage – this is water taken up by
vegetation. It is all the moisture in vegetation at
any one time.
6. • Surface storage – the total volume of water held
on the Earth’s surface in lakes, ponds and
puddles.
• Groundwater storage – the storage of water
underground in permeable rock strata.
• Channel storage -the water held in a river or
stream channel.
c. Flows and Processes – water moving from one
place to another
• Base flow – water that reaches the channel by fast
through flow and from permeable rock below the
water table forms base flow.
• Channel flow – the movement of water within
the river channel. This is also called a river’s
discharge.
7. • Groundwater flow – the deeper movement of
water through underlying permeable rock strata
below the water table.
• Limestone is highly permeable with lots of joints
and can lead to faster groundwater flow.
• Infiltration – the downward movement of water
into the soil surface.
• Interflow – water flowing downhill through
permeable rock above the water table.
• Percolation – the gravity flow of water within
soil.
• Stem flow – water running down a plant stem or
tree trunk.
8. • Surface Runoff – the movement of water over the
surface of the land, usually when the ground is
saturated or frozen or when precipitation is too
intense for infiltration to occur.
• Through flow- the movement of water down
slope within the soil layer.
• Through flow is fast through pipes (cracks in the
soil or animal burrows).
d. Outputs – water leaving the system
• Evaporation – the transformation of water
droplets into water vapor by heating.
9. • Evapo-transpiration – the loss of water from a
drainage basin into the atmosphere from the
leaves of plants + loss from evaporation.
• Transpiration – evaporation from plant leaves.
• River discharge – the amount of water that
passes a given point, in a given amount of time.
10.
11. B. Geology
Geology refers to the bedrock underlying
an area or the type of rock or mineral
formations of the watershed.
These bedrock formations developed as a
result of geologic processes that have
operated for many years.
The geology of the watershed must be
known in order to estimate the watershed’s
hydrological reaction.
The geology of the watershed substrate
influences both the runoff and the
groundwater flow.
The main geologic characteristic is the
permeability of the soil substrate.
11
12. A watershed that has an impermeable
substrate presents a faster and more violent
increase of the runoff in comparison to a
watershed with a permeable substrate.
A watershed with a permeable substrate
will provide a base run-off during dry
periods that will last longer.
Weak geology of the watershed combined
with rainfall and human activities lead to
various forms of landslide in the watershed.
12
13. Other characteristics related to geology:
Historical geology of the watershed
Local and regional structural formations
(e.g., faults, basins, etc.)
Types of rock groups present in the
watershed
Stratigraphy of the rock types
A geologic cross-section
Near-surface geology, including
descriptions of the major soil units;
glacial and/ or depositional history
13
14. C. Soil
Soil consists of material weathered in place
from the underlying parent material (i.e.,
bedrock) and mixed with organic material
near the surface.
The knowledge of soils, their physical and
chemical properties are important in
watershed management planning.
Because,
It helps in understanding the soil fertility
and productivity of a watershed.
Soil particles and their sizes are
important factors for soil erosion.
14
15. The detachability and transportability of soil in
the erosion process is based on kind and size of
soil particles.
For example, the clay particles are
difficult to detach than sand but easier to
transport.
Infiltration capacity of soil play
important role in soil erosion.
When rainfall intensity exceeds the
infiltration capacity of soil, runoff or
overland flow occurs, which causes erosion.
If the infiltration capacity of soil is higher
than the intensity of rainfall, then the runoff
or overland flow will be lower and less
erosion occurs.
15
16. • Soils are classified according to their infiltration
rate after prolonged wetting with all vegetation
removed. They are divided into four hydrologic
groups:
• Group A soils have low runoff potential and
high infiltration rates even when thoroughly
wetted.
• They consist chiefly of deep, well to excessively
drained sands or gravels.
• These soils have a high rate of water transmission
(greater than 0.30 in/hr).
17. • Group B soils have moderate infiltration rates
when thoroughly wetted and consist chiefly of
moderately deep to deep, moderately well to well
drained soils with moderately fine to moderately
coarse textures.
• These soils have a moderate rate of water
transmission (0.15 - 0.30 in/hr).
• Group C soils have low infiltration rates when
thoroughly wetted and consist chiefly of soils
with a layer that impedes downward movement
of water and soils with moderately fine to fine
texture.
• These soils have a low rate of water transmission
(0.05 - 0.15 in/hr).
18. • Group D soils have very high runoff potential.
• They have very low infiltration rates when
thoroughly wetted and consist chiefly of clay
soils with a high swelling potential, soils with a
permanent high water table, soils with a clay
pan or clay layer at or near the surface, and
shallow soils over nearly impervious material.
• These soils have a very low rate of water
transmission (0.0 - 0.05 in/hr).
19. D. Topography
Topography is a product of the
underlying geologic formations and the
geologic history of an area, as well as
human activities that alter the natural
landscape.
The topography or terrain of an area has
a significant influence on:
Infiltration rate
Runoff rate
Erosion rate
Sedimentation
Vegetation type
Flood storage and conveyance
19
20. Natural storage of water in depressions on
the ground surface during rainfall reduces
surface runoff volume and velocity.
On relatively flat terrain, precipitation stored
in surface depressions has the opportunity to
infiltrate into the soil.
Depending on soil characteristics and
vegetative cover, the rainwater may be taken
up by plants and transpired back to the
atmosphere, flow subsurface down the slope,
and/or percolate to the groundwater.
However, as the surface slope increases, the
water storage decreases.
20
21. In small watersheds on steep hilly slopes,
most surface depressions are filled to
capacity very quickly, reducing
opportunities for infiltration and increasing
overland runoff.
Increasing surface slope not only decreases
surface storage and infiltration, but also
increases the velocity of overland runoff
generated.
Increased runoff velocity means that
erosion rates increase as soil particles are
more easily detached and transported down
the slope.
21
22. The topography of the watershed also
determines the character of the stream
valleys and streams themselves.
For example,
The steeper headwater areas of a watershed
tend to have steeper stream channels
confined by adjacent hilly slopes.
As a result, headwater streams generally
have more energy available to erode and
transport stream bank and streambed
materials.
They also have relatively few areas to store
flows that overtop the stream banks.
As a consequence, floodwaters are
conveyed quickly to downstream reaches.
22
23. Lowland areas (downstream of the watershed)
tend to be flatter, with broader valleys.
unaltered streams flowing across broad, flat
valleys tend to have less energy available for
erosion and transport of materials.
they usually have significant areas available
for storing and slowing the downstream
conveyance of floodwaters.
23
24. E. Geomorphology
Geomorphology refers to the physical features
of the surface of the earth and their relation to
its geological structures.
It includes size, length, shape, slope, etc. of the
watershed.
Size of a watershed reflects the volume of water
that can be generated from a rainfall.
Length of the watershed is the distance traveled
by the surface drainage and sometimes more
appropriately labeled as hydrologic length.
Shape of a watershed reflects the way that
runoff will be collected at the outlet.
Slope of a watershed affects the force of runoff.
24
25. i. Size of a Watershed
• A large watershed takes longer time for draining
the runoff to the outlet than smaller watershed
and vise-versa.
a. Drainage area-watershed area
• The drainage area/watershed area is the single
most important factor affecting the magnitude of
peak flows.
• Watershed area is used to indicate the potential
for rainfall to provide a volume of runoff,
whereas length of watershed indicates the time
taken by runoff through watershed.
26. • Accordingly, large watershed area indicates high
volume of runoff and long watershed indicates low
volume of runoff.
• In general, a large watershed area implies a large peak
flow; however, human activities like urbanization can
modify this behavior.
Factors responsive to watershed size:
• Overland flow is more in small watersheds as
there is less network of drainage systems while in
large watersheds channel flow is dominant
• Sheet and rill erosion is dominant in small
watersheds while in large watersheds gully
erosion could be more significant
• Channel/Stream storage is more significant in
larger watersheds
27. • Development of erosion: sheet erosion, rill
erosion, gully/channel erosion, stream flow
b. Channel/stream Length
• The effective length of a channel depends on flow
magnitude.
• Large flows overtop the banks and fill the
floodplain whose length is usually shorter than
that of the meandering streambed.
• A long drainage channel usually indicates a long
runoff removal time.
• Therefore, longer channels cause a response to
rainfall slower than for shorter channels.
28. c. Shape of a Watershed
• The shape of the watershed has an effect on the
rate of runoff.
• The rate of runoff will be lower for a long narrow
watershed than for a fan-shaped watershed.
• Watersheds have an infinite variety of shapes,
and the shape supposedly reflects the way that
runoff will “bunch up” (gathered) at the outlet.
• A circular watershed would result in runoff from
various parts of the watershed reaching the outlet
at the same time.
• Long and narrow watersheds are likely to have
longer time of concentration, resulting in lower
runoff rates than broad and compact watersheds
of the same size.
29. Example:
i. Fan-shape- shape looks like part of a circle
[tends to produce higher runoff very early]
ii. Fern shape- shape looks like feathers of birds
[tends to produce less runoff]
• In general terms, in more compact watershed, the
runoff hydrograph is expected to be sharper with
a greater peak and shorter duration.
• For a watershed that is partly long and narrow
and partly compact, the runoff hydrograph is
expected to be a complex composite of the above
mentioned hydrographs
30. ii. Slope of a Watershed
• The principal effect of land slope is on the rate of
runoff.
• Runoff will flow faster on a steeper slope.
• This results in higher peaks at downstream
locations.
• The effect of land slope on the volume is usually
minor.
• Slope determines the flood magnitude and
speed: naturally, the steeper the slope of a field,
the greater the speed of runoff.
• Soil erosion by water also increases as the slope
length increases due to the greater accumulation
of runoff.
36. • The slope is obtained by dividing the rise over run.
• Multiply this ratio by 100 to express slope as a
percentage.
• The slope angle expressed in degrees is found by
taking the arctangent of the ratio between rise and
run.
• Here we want to find the average slope of the face of
this mountain (the section from point A to point B).
• The vertical distance or rise is the elevation difference
between point A and point B.
• Checking the topo map below Point A is at 2500m.
• Contour interval is 20m (five contour lines per 100m
elevation difference).
• Therefore, elevation of point B is 2780m.
Rise = 2780m – 2500m = 280m.
37. • The run or the horizontal distance between two points
is found by using the map's scale bar.
• Using a ruler we can measure the scale bar of a Google
Map at bottom left corner.
• 17mm or 1.7cm on the map is equal to 100m in the real
world.
• Again using a ruler, the next step is measuring the
horizontal distance between point A and point B on
the map: 42mm or 4.2cm.
• Calculating the real world distance: Run = 4.2cm *
(100m / 1.7cm) = 247m.
• (Note that the numbers corresponding to
measurements on the image may be different on your
computer monitor due to resolution difference or
when the image is printed. The end result however
should be the same).
38. • Gradient (decimal) = Rise / Run = 280m / 247m
= 1.1336
Here, for every 1 unit (e.g. meter, foot, etc.) of
horizontal travel, there is 1.1336 units of altitude
gain or vertical increase.
• Alternatively for every 0.882 unit horizontal
travel, there is one unit of vertical gain.
• Therefore, as a ratio, the gradient would be
expressed as (1 in 0.882).
Gradient (percentage) = 1.1336 * 100 = 113.4%
• Slope angle is the angle α in the diagram.
• By definition of tangent in trigonometry:
tan α = Rise / Run
39. Slope classification on the basis of % values
Code Class Description
A Little or none Little or none slope: 0-3%
gradient
B Gentle Gentle slopes: 4-9% gradient
C Moderate Moderate slopes: 10-15%
gradient
D Steep Steep slopes: 16-30% gradient
E Extremely steep Extremely steep slopes: 31-60%
gradient
F Excessively steep Excessively steep slopes: > 60%
40. Slope angle classification
• Slope angles are classified on the basis of
geomorphological parameters.
• Although the continuous variables of slope angle
are arbitrary, but it delineates the micro units of
landform.
• For the hydrological purpose, the slope angles are
best determiner of sediment load transported by
a stream.
• Taking all these into consideration, the slope
angles are divided into five categories
41. Slope gradient classification on the basis of angle classes
Angle class Description
< 12° Gentle slope
12-22° Moderate
23-31° Moderately steep slope
32-45° Steep slope
> 45° Very steep slope
42. • Some slope features are important in field studies
like geomorphology, avalanches and backcountry
travel decision making.
• Examples include convex and concave slopes.
• Convex slopes roll from less steep (gentler) to
steeper terrain.
• Depending on the contour interval and the size of
the feature, convexities on terrain may be detected
by wider contour spacing on top and closer
contour lines on the bottom of the roll.
• Concave slopes go from steeper to gentler terrain
with movement down slope.
• There are closer contour spacings at the top and
wider spacings at the bottom indicating steeper
and gentler slopes, respectively.
43.
44.
45. • In watershed rehabilitation and management, it
is important to determine how much proportion
of the watershed lies within each class of the
slope gradient.
46. iii. Roughness
• Roughness affects the velocity of overland flow
and stream flow.
• A rough channel will cause smaller peaks than a
smooth channel.
• For a given discharge, stage levels (water surface
elevations) in a stream are higher for rough
channels.
iv. Stream Order
• Stream order is a measure of the degree of
branching of streams within a Watershed.
• First order streams are defined as those channels
that have no tributaries.
47. • In this case, the flow is depended entirely on
surface overland flow to them.
• The junction of two first order stream forms a
second order channel.
• Please note that when a low order stream
segment joins the higher order stream segment,
then the order of the stream remained as it is
• Second order channel receives flow from the two
first order channels that form it and from
overland flow from the ground surface and
might receive flow from another first order
channel that flow directly in to it.
48. • Third order channel is formed by the junction of
two second order channels.
• It receives flow not only from the two second
order channels that form it, but also direct
overland flow and possibly from first order
channels that flow directly into it and possibly
from other second order stream that might join
it.
• In general, an nth order stream is a tributary
formed by two or more streams of order (n-1)
and streams of lower order.
• Numerical ordering begins with the tributaries
at the streams headwaters being assigned the
value one.
50. Stream/channel and basin Order
• The bifurcation ratio (Rb) is defined as the ratio of
the number of streams of any order to the number
of streams of the next higher order.
• The bifurcation ratio is calculated as:
Rb = Ni/Ni+1
• Values of Rb typically range from the theoretical
minimum of 2 to around 6.
• The bifurcation ratio of a whole watershed is the
average of the bifurcation ratios of each stream
order
• The lower the value of bifurcation ratio, the flatter
or rolling the drainage basin/watershed is.
• It is also suggestive that the area is underlain by a
homogenous rock
• The higher the value of bifurcation ratio, the
steeper and more dissected the drainage basin.
52. v. Drainage Density
• The drainage density is a measure of the total
length of well defined channels/streams that
drain the watershed (sometimes measured as the
blue lines representing the streams on a
topographic map).
Drainage density affects the response of the
watershed to rainfall.
High densities usually allow fast runoff removal.
Mathematically, drainage density is defined as the
sum of the lengths of all the streams (in km or
miles) divided by the total watershed area (km2 or
mile2).
53. Where,
–Dd is drainage density (km km-2)
–L is length of stream segment (km)
–A is basin area/watershed area
(km2) or (mi²)
• This ratio can be determined from
topographic maps.
• A high drainage density reflects
highly dissected basins, and relatively
rapid response to a rainfall input,
while low drainage density reflects a
poorly drained basin with low
hydraulic response.
54. Therefore, greater peaks and hydrographs with
shorter durations are expected for watersheds
with higher drainage densities.
The effect of drainage density on runoff volume
is associated with the time during which the
runoff remains in the watershed.
Low densities allow for long residence times;
therefore, abstraction mechanisms have more
time to remove water.
55. • Stream density – also known as stream
frequency over the basin, and it is expressed as
the ratio of the total number of streams to the
area of the basin.
• Stream density (Sd) = No. of streams/Basin
Area.
• It is also possible to calculate Sd of first order
streams over the watershed, as
• Sd1 = No. of 1st order streams/basin Area
56. vi. Drainage Patterns
This refers to the arrangement of streams in a
drainage, which often reflects structural and/ or
lithological control of underlying rocks.
–Drainage patterns tell much about the
substance of which the land surface is made
• The drainage pattern of an area is the outcome of
– the geological processes,
– nature and structure of rocks,
– topography,
– amount of flow
– periodicity of the flow
57. Some examples of drainage pattern: dendritic,
parallel, rectangular, radial, centripetal, …
a. Dendritic drainage pattern
–Develops in area where the type of rocks remain
the same all over the basin and where no
geological processes, like folding or faulting
have created structures that would control the
development of river system
–Weak rock structure usually form dendritic
drainage pattern
–Dendritic drainage pattern is characterized by
the fact that tributaries flow in the same
direction as the main stream, joining at an acute
angle
58. b. Radial drainage pattern
- it is made up of a pattern of stream flowing
outward, down the slopes of a dome or cone-
shaped upland
c. Rectangular drainage pattern
- The rectangular pattern is found in regions that
have undergone faulting.
- Movements of the surface due to faulting offset
the direction of the stream.
- As a result, the tributary streams make sharp
bends and enter the main stream at high angle
d. Trellis drainage pattern
- It develops in area where softer and harder rocks
alternate with one another or where folding and
faulting results in the formation of structures that
control the development of river system
63. F. Climate
Climate refers to the prevailing weather
conditions in an area for long period of
time, which affects the flow, pattern, and
shape of streams.
Climate influences:
Amount and type of precipitation
Timing of runoff
Evaporation rate
Vegetation type
Erosion rate
Groundwater recharge rate
Climate influences the amount and seasonal
distribution of precipitation and thereby determines
other processes. 63
64. Rainfall and temperature play crucial
roles in watershed condition.
There is direct relationship between the
amount of rainfall and erosion in a
watershed.
Rainfall intensity influences both the rate
and volume of runoff and then the scale
of erosion.
Temperature affects climatic type, which
governs the types of crop grown and the
amount of ground cover that exists in
watershed.
Temperature is important in producing
desired level of ground cover to protect
soil from erosion and landslides in the
watershed.
64
65. Climate also affects stream flow and
sediment by influencing the type and
density of vegetation in a watershed.
In addition, climate has a significant effect
on the chemical characteristics of streams.
The chemical composition of streams
derives from atmospheric, soil and rock
sources.
Chemical and physical weathering of rock
and soil contribute the greatest proportion
of dissolved and suspended material to
natural stream systems.
65
66. G. Land use/ land cover
Land cover refers to the types of
vegetation found in an area.
A related factor is land use, which refers
to the types of activities which people
conduct on a given land area.
Land use and land cover are major
factors controlling the volume and rate of
runoff from a watershed, soil erosion and
sediment loadings, the stability of
valley/hilly slopes, stream channel
morphology, and overall water quality.
The location and intensity of a particular
land use activity will determine its effect
on the watershed.
66
67. Interception on leaves, stems, and surface
litter of vegetation allows water to be
retained during smaller storms,
evaporating back into the atmosphere
without ever reaching the ground.
It also reduces the impact of raindrops by
preventing the detachment of soil particles.
Vegetation increases infiltration by
preserving loose soil structure and
scattering the flow of water.
Vegetation also interrupts overland flow,
slowing the velocity, physically binding the
soil and inhibiting erosion.
67
68. 2.2 Socioeconomic Characteristics of a Watershed
This includes the social, cultural and economic
condition of the watershed community.
a. Socio-cultural factors
The information on the people's social and
cultural norms and activities should be collected
and analyzed for watershed management.
A planner must carefully collect and study socio-
cultural information before making any
recommendations for drastic change.
Population growth in a watershed results
degradation of watershed and its environment.
68
69. Population growth results in deficit of
food, fodder, wood and land.
This will result in cultivation of marginal
land, over grazing, over cutting and
removal of trees.
The consequence of such activities result
in land degradation like soil erosion/
watershed/ environmental degradation.
Cultural information of watershed is
equally important for the development of
watershed management.
Because, watershed management programs
can bring cultural transformation in the
society. 69
70. To consider local culture in planning is to
minimize possible resistance in future
implementation.
Farmers are relatively conservative.
Any improvement which is compatible with the
local culture and with a gradual path will have
better potential for success.
b. Economic factors
Among other factors, economic factors also
play crucial role in soil conservation and
watershed management.
Soil conservation and watershed management
programs need investment.
Poor farmers cannot invest in soil and water
conservation because of low level of economy.
70