EVAPOTRANSPIRATION Flashcards
(22 cards)
the process by which water moves from the land to the atmosphere, combining evaporation from soil and water surfaces with transpiration from plants.
Evapotranspiration
the process by which water from water bodies (such as rivers and lakes) or soil is converted to vapor.
Evaporation
the evaporation of water from a plant’s leaves, stem, or flowers.
Transpiration
the loss of water from the soil, both by evaporation from the soil surface and by transpiration from the leaves of the plants growing on it.
Evapotranspiration
Factors Affecting Evapotranspiration
(a.) Energy Availability (Radiation)
(b.) Humidity Gradient
(c.) Wind above Surface (Aerodynamics)
(d.) Water/Moisture Availability
(e.) Vegetation
(f.) Stomatal Resistance
(g.) Soil Characteristics
(h.) Plant Maturity
Sunlight is the source of energy in evapotranspiration where it cannot go to the process if there’s no sunlight. The more you near the equator, the higher the rate of evapotranspiration.
Energy Availability (Radiation)
The gradual change in moisture levels in the air, often measured as a difference in humidity over a specific distance or area.
Humidity Gradient
The effect of wind to break the surface tension in which the group of water molecules break to have a faster process of evaporation in air.
Wind above Surface (Aerodynamics)
Presence of water is needed. No water/moisture, no process of evaporation will happen. It is based on a certain places (e.g. desert countries, high temperature countries)
Water/Moisture Availability
Act or process of vegetation or growing as a plant found in a particular area.
Vegetation
Factor in which plants have different kinds of mechanism and transpiration depending on the type of it (e.g. plants with open and closed stomata).
Stomatal Resistance
Ability of plants to grow based on the different soil types, soil infiltration capacity, etc.
Soil Characteristics
The stage of development of plant. When a plant is newly planted, it only needs a little water requirement, but when it is about to be harvested, it needs a higher water requirement.
Plant Maturity
varies with latitude,
season of the year, time of day, and cloud cover.
Evapotranspiration
METHODS IN ESTIMATING EVAPOTRANSPIRATION
- Water Budget Equation
- Penman-Monteith Equation
- Pan Evaporation
The area of land draining into a steam or a water course at a given location
Catchment Area
also called as drainage area or drainage basin.
Catchment Area
a widely used method for estimating evapotranspiration (ET), which is the combined process of evaporation from the soil and plant surfaces and transpiration through plant stomata.
The Penman-Monteith equation
This equation is particularly important in fields such as agriculture, hydrology, and climate science for managing water resources, irrigation scheduling, and understanding the water cycle.
The Penman-Monteith equation
The Penman-Monteith equation was developed by combining earlier work by ______ who devised a method to estimate evaporation from open water, bare soil, and grass, with modifications by Monteith (1965), who adapted it to account for plant physiology—specifically resistance to vapor flow through stomata.
Howard Penman (1948)
standardized the Penman-Monteith method to estimate reference evapotranspiration (ET₀) from a hypothetical reference grass crop
The Food and Agriculture Organization (FAO) of the United Nations
The FAO Penman-Monteith Equation
is a measurement method used to estimate the evaporation component of evapotranspiration. It involves observing the water loss from a standardized container
Pan evaporation
