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2. Potential evapotranspiration - Wikipedia

   en.wikipedia.org/wiki/Potential_evapotranspiration

   Monthly estimated potential evapotranspiration and measured pan evaporation for two locations in Hawaii, Hilo and Pahala. Potential evapotranspiration is usually measured indirectly, from other climatic factors, but also depends on the surface type, such as free water (for lakes and oceans), the soil type for bare soil, and also the density and diversity of vegetation.

3. Evapotranspiration - Wikipedia

   en.wikipedia.org/wiki/Evapotranspiration

   Evapotranspiration can never be greater than potential evapotranspiration, but can be lower if there is not enough water to be evaporated or plants are unable to transpire maturely and readily. Some US states utilize a full cover alfalfa reference crop that is 0.5 m (1.6 ft) in height, rather than the general short green grass reference, due to ...

4. Crop coefficient - Wikipedia

   en.wikipedia.org/wiki/Crop_coefficient

   Potential evapotranspiration (PET), is the evaporation and transpiration that potentially could occur if a field of the crop had an ideal unlimited water supply. RET is the reference ET often denoted as ET 0 .

5. Blaney–Criddle equation - Wikipedia

   en.wikipedia.org/wiki/Blaney–Criddle_equation

   Given the limited data input to the equation, the calculated evapotranspiration should be regarded as only broadly accurate. Rather than a precise measure of evapotranspiration, the output of the equation is better thought of as providing an order of magnitude. [2] The inaccuracy of the equation is exacerbated by extreme variants of weather.

6. Penman equation - Wikipedia

   en.wikipedia.org/wiki/Penman_equation

   Specifically the Penman–Monteith equation refines weather based potential evapotranspiration (PET) estimates of vegetated land areas. [1] It is widely regarded as one of the most accurate models, in terms of estimates. [citation needed] The original equation was developed by Howard Penman at the Rothamsted Experimental Station, Harpenden, UK.

7. Penman–Monteith equation - Wikipedia

   en.wikipedia.org/wiki/Penman–Monteith_equation

   E = Mass water evapotranspiration rate (g s −1 m −2) ET = Water volume evapotranspired (mm s −1) Δ = Rate of change of saturation specific humidity with air temperature. (Pa K −1) R n = Net irradiance (W m −2), the external source of energy flux G = Ground heat flux (W m −2), usually difficult to measure c p = Specific heat ...

8. Thornthwaite climate classification - Wikipedia

   en.wikipedia.org/wiki/Thornthwaite_climate...

   After being criticized for making climatic classification complex, Thornthwaite switched vegetation with the concept of potential evapotranspiration (PET), which represents both precipitation effectiveness and thermal efficiency. [5] Estimated PET can be calculated using Thornthwaite's own 1948 equation. [2]

9. HBV hydrology model - Wikipedia

   en.wikipedia.org/wiki/HBV_hydrology_model

   Third, the actual Evapotranspiration (ETPa) is calculated, first by using an external model (such as Penman-Montieth) for finding the potential ETP and then fitting the result to the temperatures and the permanent wilting point(PWP) of the catchment in question. A parameter C which reflects the increase in the ETP with the differences in ...