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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. Aridity index - Wikipedia

    en.wikipedia.org/wiki/Aridity_index

    In 1948, C. W. Thornthwaite proposed an AI defined as: = where the water deficiency is calculated as the sum of the monthly differences between precipitation and potential evapotranspiration for those months when the normal precipitation is less than the normal evapotranspiration; and where stands for the sum of monthly values of potential evapotranspiration for the deficient months (after ...

  5. 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 .

  6. Holdridge life zones - Wikipedia

    en.wikipedia.org/wiki/Holdridge_life_zones

    Potential evapotranspiration (PET) is the amount of water that would be evaporated and transpired if there were enough water available. Higher temperatures result in higher PET. [5] Evapotranspiration (ET) is the raw sum of evaporation and plant transpiration from the Earth's land surface to atmosphere. Evapotranspiration can never be greater ...

  7. Semi-arid climate - Wikipedia

    en.wikipedia.org/wiki/Semi-arid_climate

    It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-arid climates, depending on variables such as temperature, and they give rise to different biomes.

  8. Transpiration - Wikipedia

    en.wikipedia.org/wiki/Transpiration

    Drier surroundings give a steeper water potential gradient, and so increase the rate of transpiration. Wind: In still air, water lost due to transpiration can accumulate in the form of vapor close to the leaf surface. This will reduce the rate of water loss, as the water potential gradient from inside to outside of the leaf is then slightly less.

  9. 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.