Evapotranspiration

Thornthwaite Mather method

Step 1. Calculate the monthly heat index (i): Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle i=\left ( \frac{T}{5} \right )^{1.514}} where: T = mean monthly temperature.

Step 2. Calculate the annual heat index (I): Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle I=\sum_{i=1}^{12}i}

Step 3. Calculate an uncorrected Potential Evapotranspiration (PET_uncorrected): Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle PET_{uncorrected}=1.6\cdot \left ( \frac{10\cdot T}{I} \right )^{\alpha }}

where: α = 6.75 x 10^-7 I³ - 7.71 x 10^-5 I²+ 0.0179 I + 0.49

The quantity of water transpired (given off). Retained in plant tissues, and evaporated from plant tissues and surrounding soil surfaces. Quantitatively it is usually expressed in terms of depth of water per unit area during a specified period. e.g. mm/day

The combined loss of water to the atmosphere from land and water surfaces by evaporation and from plants by transpiration.