Evapotranspiration is the combined process of evaporation from soil and transpiration from plants. It plays an important role in the water cycle and energy balance. There are three main types of evapotranspiration - potential, referential, and actual. Environmental factors like temperature, humidity, radiation, and wind, as well as plant factors like leaf area index and root depth, and soil factors like texture and moisture content influence the evapotranspiration rate. Direct measurement methods include water balance and energy balance approaches, while indirect methods include lysimeters and meteorological data equations. Accurately measuring and estimating evapotranspiration is important for irrigation management and assessing climate change impacts.
Influence of microclimate, plant, soil and cultural factors on ET; techniques...Abhilash Singh Chauhan
INTRODUCTION
The deficiencies and surpluses of water are often the most important of the various factors influencing plant growth.
They are, at the same time, the most difficult to control.
At present adequate theory and measuring techniques for predicting the rate of soil water loss by evapotranspiration exist for only a few special combinations of plant and climatic conditions.
A better understanding of the factors influencing this process is necessary to help pave the way for the development of methods for increasing the efficiency of water utilization by crops.
The rate of water loss by the processes of evaporation and transpiration is the resultant of five controlling factors, viz:
Climate
Soil Moisture
Plant Cover
Soil Texture and Structure
Soil and Crop Management
penman-monteith approach is the basis of this equation. it is used to calculate reference evapotranspiration for a particular area, there by we can calculate potential evapotranspiration
Influence of microclimate, plant, soil and cultural factors on ET; techniques...Abhilash Singh Chauhan
INTRODUCTION
The deficiencies and surpluses of water are often the most important of the various factors influencing plant growth.
They are, at the same time, the most difficult to control.
At present adequate theory and measuring techniques for predicting the rate of soil water loss by evapotranspiration exist for only a few special combinations of plant and climatic conditions.
A better understanding of the factors influencing this process is necessary to help pave the way for the development of methods for increasing the efficiency of water utilization by crops.
The rate of water loss by the processes of evaporation and transpiration is the resultant of five controlling factors, viz:
Climate
Soil Moisture
Plant Cover
Soil Texture and Structure
Soil and Crop Management
penman-monteith approach is the basis of this equation. it is used to calculate reference evapotranspiration for a particular area, there by we can calculate potential evapotranspiration
Introduction
Hydrology
Water cycle
Watershed Development
Integrated Watershed Management
Water Conservation & Harvesting
Basic introduction of hydraulic structures.
conclusion
references
Use of drones in monitoring of microclimate crisisWorkswell
✔ https://www.drone-thermal-camera.com/products/wiris-pro-sc-therma-camera-for-the-most-challenging-aerial-thermography/
We know, that not only the “greenhouse effect” is responsible for climate change. Although it is mentioned in this context very often and nearly often exclusively.
But warming due to land cover (vegetation) change may explain as much as 18% of current global warming trends.
Thermal imaging camera Workswell WIRIS ProSC allows to measure surface temperature over large areas very accurately, with high sensitivity and stability.
Adaptation to global change must include prudent management of groundwater as a renewable, but slow-feedback resource in most cases. Groundwater storage is already over-tapped in many regions, yet available subsurface storage may be a key to meeting the combined demands of agriculture, industry, municipal and domestic water supply, and ecosystems during times of shortage.
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.
Introduction
Hydrology
Water cycle
Watershed Development
Integrated Watershed Management
Water Conservation & Harvesting
Basic introduction of hydraulic structures.
conclusion
references
Use of drones in monitoring of microclimate crisisWorkswell
✔ https://www.drone-thermal-camera.com/products/wiris-pro-sc-therma-camera-for-the-most-challenging-aerial-thermography/
We know, that not only the “greenhouse effect” is responsible for climate change. Although it is mentioned in this context very often and nearly often exclusively.
But warming due to land cover (vegetation) change may explain as much as 18% of current global warming trends.
Thermal imaging camera Workswell WIRIS ProSC allows to measure surface temperature over large areas very accurately, with high sensitivity and stability.
Adaptation to global change must include prudent management of groundwater as a renewable, but slow-feedback resource in most cases. Groundwater storage is already over-tapped in many regions, yet available subsurface storage may be a key to meeting the combined demands of agriculture, industry, municipal and domestic water supply, and ecosystems during times of shortage.
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.
The loss of water from aerial parts of plants in the form of vapor is known as transpiration.
The loose arrangement of the living thin walled mesophyll cells, which results in an abundance of inter cellular space provides an ideal condition for the vaporation of water from internal leaf surface.
Part of the epidermal surface of the leaf is made up of a great number of microscopic pores called stomata.
The water balanced of a place, whether it be an agricultural field, watershed, or continent, can be determined by calculating the input, output, and storage changes of water at the Earth's surface. The major input of water is from precipitation and output is evapotranspiration. The water balance is intended for use as a screening tool to further evaluates water resources allocations within the watershed and to identify water balance components that may require further analysis during the next levels of watersheds planning. The study area chosen for the present study area is Doddavalabhi sub watershed which falls in Kolar taluk of Kolar district. The study areas geographically lies between 760 8’ 0” E and 760 23’ 0” E longitude and 120 20’ 0” N and 120 28’ 0” N latitudes with an area 15.20 sq.km. For the determination of crop water requirement for Kolar major crops considered are ragi and groundnut with the crop period of 120 days and 140 days respectively. The year and monthly wise potential evapotranspiration and actual evapotranspiration is calculated by using penman method, blaney-criddle method, pan evaporation and radiation methods. The year wise potential evapotranspiration calculated by Blaney-criddle is maximum 645.66 mm during 2014, in this year monthly PET is maximum in July month ie 150.4mm. The year wise potential evapotranspiration calculated by Pan Evaporation is maximum 236.43 mm during 2014, in this year monthly PET is maximum in July month ie 56.67mm. The Year wise actual evapotranspiration is also maximum during 2014 for both ragi and groundnut. Hence Blaney criddle method is best suitable since it provides the most satisfactory results compared to other methods because this method is suggested for areas where available climatic data cover air temperature data only.
Effect of Harvest of Air Relative Humidity on Water and Heat Transfer in Soil...IJERA Editor
In this work, the main objective is to analyze the effect of the harvest of air relative humidity on soil temperature, soil water storage and evaporation. An experiment work was conducted in order to evaluate the quantity of soil water adsorbed by harvesting of relative air humidity. This experimental work was conducted on hilly areas with various hypsographic and microclimatic conditions greatly affecting daily fluctuations of air humidity and soil characteristics. The metrological data needed by SISPAT model were obtained by using a Campbell Scientific equipments Station recorder on data loggers every half hour. A numerical model based on SiSPAT (Système d’Interaction Sol Plante Atmosphère) formulation is adopted. The general equations of the proposed model are based on heat and mass transfer in the soil, atmosphere and plant system. This study shows that Soil Water Adsorption (SWA) induce an increasing in the total evaporation and in soil water storage especially on the upper layers. The effect of Soil Water Adsorption on soil temperature appears for the first layers of soil and become absent in the profound zone because the vapour condensation phenomenon is very important at night for the first layers.
Effect of Harvest of Air Relative Humidity on Water and Heat Transfer in Soil...IJERA Editor
In this work, the main objective is to analyze the effect of the harvest of air relative humidity on soil temperature, soil water storage and evaporation. An experiment work was conducted in order to evaluate the quantity of soil water adsorbed by harvesting of relative air humidity. This experimental work was conducted on hilly areas with various hypsographic and microclimatic conditions greatly affecting daily fluctuations of air humidity and soil characteristics. The metrological data needed by SISPAT model were obtained by using a Campbell Scientific equipments Station recorder on data loggers every half hour. A numerical model based on SiSPAT (Système d’Interaction Sol Plante Atmosphère) formulation is adopted. The general equations of the proposed model are based on heat and mass transfer in the soil, atmosphere and plant system. This study shows that Soil Water Adsorption (SWA) induce an increasing in the total evaporation and in soil water storage especially on the upper layers. The effect of Soil Water Adsorption on soil temperature appears for the first layers of soil and become absent in the profound zone because the vapour condensation phenomenon is very important at night for the first layers.
Evapotranspiration partitioning components in an irrigated winter wheat field...Agriculture Journal IJOEAR
Abstract— The arid and semi-arid regions constitute roughly one third of the total earth’s surface. In these regions water scarcity is one of the main limiting factors for economic growth. The impact of such water scarcity is amplified by inefficient irrigation practices, especially since about 85% of available water is used for irrigation in these regions. Therefore, a sound and efficient irrigation practice is an important step for achieving sustainable management of water resources in these regions. In this regard, a better understanding of the water balance is essential to explore water-saving techniques. In the context CRP project, experimental setups were conceived to monitor seasonal water consumption on the wheat crop irrigated by flood irrigation in Sidi Rahal station (middle of morocco. The partitioning of evapotranspiration compounds shows that transpiration dominates the evaporation about 68 % for three days (22, 23 and 24 February 2012). In addition the wheat absorbs the soil water from 10 cm to 20 cm (90%) at this growing stage according to the multiple-source mass balance assessment.
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Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
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2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
2. EVAPOTRANSPIRATION
Presented to: Dr. Shakil Ahmad
Presented by: Maria Jabeen
MSBT-29F20(MS-Replica)
Water resources and its management in Pakistan
2
3. Contents:
◦ Introduction
◦ Importance
◦ Types of Evapotranspiration
◦ Factors affecting Evapotranspiration
◦ Methods and Estimation of Evapotranspiration
◦ Conclusion
◦ References
3
4. Evapotranspiration:
◦ Evapotranspiration is the process in which evaporation and transpiration occur simultaneously.
◦ Evaporation is the process in which liquid form of water is converted into vapor form and removed from the
evaporating surfaces such as soil, canopy interception and water bodies.
◦ In transpiration the movement of water take place in the plant and exit of water as vapor form through stomata in
the leaves. Transpiration is the evaporation of water from the leaves.
◦ It is symbolically represented by ET.
4
5. Continue…
◦ It is also defined as “transfer of energy from the earth surface
to the atmosphere in the form of latent heat due to the
evaporation of water from the ground and water bodies and
transpiration of water from plants.
◦ The role of transpiration is about the 10% of moisture in the
atmosphere and the evaporation from the oceans and water
bodies about the 90%.
5
6. Importance :
◦ Evapotranspiration is the important factor in the earth energy balance because it creates the balance of
energy between the evaporation and transpiration.
◦ It is the important part of water cycle.
◦ It is very important for the irrigation practices.
6
7. Water cycle /hydrologic cycle:
◦ The process involves in the water cycle are
◦ Evaporation
◦ Transpiration
◦ Condensation
◦ Precipitation
◦ Runoff
◦ Evaporation and transpiration both are present in
the water cycle. Therefore, it is the main
component of the water cycle.
7
8. Types of Evapotranspiration:
Potential Evapotranspiration
•It is defined as the loss of water from large area
which is uniformly area with actively growing
green crop when water is not limited. It is
considered as the upper limit of
evapotranspiration for a crop.
•This is applicable under humid conditions.
Referential Evapotranspiration
•When the potential evapotranspiration is
measured at a nearby climatic condition like a
reference surface, majorly short grass.
•It used to study evaporative demand of the
atmosphere independently of crop type, crop
development and management practices.
Actual Evapotranspiration
•The total amount of water used in evaporation
and transpiration by a crop during its entire
growth season is called the AET. It is the
availability of water to the plants.
•Actual evapotranspiration become less than the
maximum evapotranspiration when the soil
moisture is limited.
8
12. Soil Factors:
◦ Soil texture and soil structure
◦ Soil moisture content
◦ Soil moisture contents also influence the evapotranspiration. When soil is lacking the moisture, the plant
begin to transpire less water which further decreases the evapotranspiration.
12
13. Measurement and Estimation of Evapotranspiration:
◦ Direct Methods :
◦ Catchment water balance , Energy balance method
◦ Indirect Methods:
◦ Lysimeter Method
◦ Meteorological methods
◦ Pan Method
13
14. Catchement water balance:
◦ Evapotranspiration can be estimated by the water balance equation :
◦ ET= P-ΔS-Q-D
◦ ET= Evapotranspiration
◦ P= precipitation
◦ ΔS= change in storage
◦ Q= stream flow
◦ D= ground water recharge
14
15. Energy balance method:
◦ The actual evapotranspiration can be estimated by the energy balance equation.
λE = the energy needed to change the phase
of water from liquid to gas
Rn = Net radiation
G = Soil heat flux
H = Sensible heat flux
15
16. Continue…
◦ In this method an instrument is used Scintillometer, soil heat flux plates and radiation meters, the
components of the energy balance can be calculated and the energy available for actual
evapotranspiration can be solved.
16
17. Lysimeter:
◦ A lysimeter is a special water tight tank containing soil and set in a cropped field (so buried that the level
of soil is the same both inside and outside the container). The same type of plants as in the surrounding
field are grown in a lysimeter. The soil in the lysimeter along with the vegetation in it is hydrologically
isolated from the surrounding soil.
17
18. Construction of Lysimeter:
◦ Lysimeters shall be designed so as to accurately reproduce the soil and soil
moisture conditions, type and size of vegetation of the surrounding area.
◦ Lysimeter studies involve growing crops in large containers and measuring the
water losses and gains. ET can be estimated by determining the amount of
water required to maintain constant soil moisture conditions within the tank.
18
19. Measurement of Evapotranspiration:
◦ Input (Rainfall R and additional water A) and output (percolated water P)
collected in the receiver, then PE can be estimated by equation.
◦ PE=R+A-P
19
20. Meteriological data:
◦ ET is commonly computed from weather data.
◦ A large number of empirical or semi-empirical equations have been developed for assessing crop or
reference crop evapotranspiration from meteorological data.
◦ Some of the methods are only valid under specific climatic and agronomic conditions and cannot be
applied under conditions different from those under which they were originally developed.
◦ Penman-Monteith method is now recommended as the standard method for the definition and
computation of the reference evapotranspiration in th is method.
20
21. Pan evaporation:
◦ Evaporation from an open water surface provides an index of the integrated
effect of radiation, air temperature, air humidity and wind on
evapotranspiration.
◦ The pan has proved its practical value and has been used successfully to
estimate reference evapotranspiration by observing the evaporation loss from
a water surface and applying empirical coefficients to relate pan evaporation
to ETo.
21
22. Conclusion:
◦ Play role in the water balance of hydrologic cycle.
◦ It maintains the energy balance.
◦ It is useful for the irrigation practices.
◦ Due to climate change, global warming which has negative impacts on ecosystems. Increase temperature
increases the evapotranspiration , increasing the radiation, increasing the wind speed .
◦ Regional evaluation of climate change impacts is necessary to evaluate the impacts on
evapotranspiration, precipitation and runoff.
22
23. References:
◦ Evaporation and Evapotranspiration measurements and estimation by
◦ Wossenu Abtew and Assefa Melesse .
◦ Evapotranspiration in the Soil-Plant-Atmosphere System by Viliam Nova´k .
◦ R. Wolfson, (May 8, 2015). Energy, Environment and Climate, 2nd ed. New York, U.S.A.: Norton, 2012.
◦
23