Great Plains Evapotranspiration by a Resistance Model Using Remotely Sensed Thermal Imagery.

摘要

Because evapotranspiration is usually a major component in the water balance, a method for estimating evapotranspiration of a large region is of major importance. Resistance forms of the energy balance equation require the measurement of a boundary layer resistance to heat or mass transport,crop and air temperature,net radiation,vapor pressure,and soil heat flux. The exact form of the equation may differ depending on the availability of input data and the specific assumptions used by the investigators. Four separate equations/techniques were tested against lysimetric and/or Bowen ratio-energy balance estimates of evapotranspiration to develop empirical equations under varying conditions. Resistance forms of the energy balance,in which data could be supplied,in part,by remote sensing,were also evaluated. Thermal scanner measurements were evaluated for estimating canopy temperature.