Climatic Assessment of the Arid Southwestern United States for Use in Predicting Evapotranspiration of Turfgrass

Abstract

Climatic conditions were assessed at three locations in the arid southwestern United States over a two year period. The three locations were Las Vegas, NV, Tucson, AZ and Palm Desert, CA. Automated weather stations monitored maximum and minimum temperature, relative humidity, solar radiation, wind run and rainfall. Data were input into the empirical based Penman combination equation to predict potential evapotranspiration (ETo). Surveys were conducted at all three locations to evaluate the soil conditions, water availability, turfgrass management and crop coefficients used. Only slight differences existed beween average monthly minimum temperatures, maximum temperatures and solar radiation at the three sites. However, differences in average monthly wind run and relative humidity at the three sites led to greater separation in the ETo estimates during summer months. These differences resulted in a 7% and 13% error in estimating monthly ETo at the Palm Desert and Tucson sites respectively, based on using th...