Desert photovoltaic power station region actual evapotranspiration estimation method

The invention discloses a method for estimating the actual evapotranspiration of a desert photovoltaic power station area. The method comprises the following steps: 1) collecting related data; 2) calculating daily scale reference evapotranspiration; 3) calculating monthly scale reference evapotranspiration ETo; 4) calculating a monthly-scale soil water storage capacity change delta S; 5) calculating monthly scale precipitation P; 6) calculating the monthly-scale actual evapotranspiration ET; 7) calculating a crop coefficient Kc; and 8) calculating the daily scale actual evapotranspiration ET. According to the method, only the meteorological observation equipment and the soil observation equipment are needed to collect basic data, and the dynamic characteristics of the daytime actual evapotranspiration in a long-time sequence can be accurately obtained; and meteorological and soil element data can be monitored synchronously, so that overall moisture balance analysis is facilitated, the water circulation proces