An Evaluation of the Thornthwaite-Holzman Equation for Evapotranspiration

Abstract

Evapotranspiration involves a complex set of processes which relate to the loss of water to the atmosphere. It involves the uptake of water by the root system of plants, its movement through the plant, and its diffusion through the stomata into the atmosphere. The term evapotranspiration (Et) includes evaporation from the soil and transpiration from vegetation. Two of the basic reasons for studying evapotranspiration are as follows: 1) Since it is the reverse process of precipitation, it has major consequences in agriculture through its control on plant growth. 2) It is one of the important energy fluxes from the earth's surface and is an integral part of the energy balance.