Consumptive Use Program (CUP) Model

Consumptive Use Program (CUP) was developed to improve Kc and crop evapotranspiration (ETc) to aid in California water planning. Site-specific total irrigation requirements for a crop are calculated by dividing the crop’s net water requirement by the weighted mean irrigation efficiency. CUP computes reference evapotranspiration (ETo) from monthly means of solar radiation, maximum, minimum, dew point temperature, and wind speed. The program uses a curve fitting technique to produce daily ETo and rainfall data for a year. Bare soil evaporation is used to estimate Kc values for the off-season and as a baseline for in-season Kc calculations. For many years, published Kc values have been used to estimate ETc from ETo. One improvement is to account for the influence of rainfall and/or irrigation frequency on Kc and ETc during initial growth. For tree crops, it is important to account for cover crops, which has not been done in the past. Another improvement is to compute and apply all ETo and Kc values on a daily basis to determine crop water requirements. Using new information on midseason Kc values and bare soil evaporation, a user-friendly Excel program, CUP, was developed to improve long-term estimates, which account for rainfall, cover crop, and immaturity effects. This paper presents the advantages of CUP

کلیدواژه ها:

Evapotranspiration ، Crop Coefficients ، Crop Water Requirements ، Irrigation