| Based on the comparisons among agricultural indexes in common use and the analysis of measured data of agricultural drought in the various climatic regions in Gansu province, it was found that soil moisture indexes could reliably express the agricultural flood/drought. It was simulated by using precipitation, irrigation freguency, evaporation and previous soil moisture etc. Total soil moistures from 0 to 50 cm of four representative stations—Wuwei, Dingxi, Xifeng, Chengxian were simulated, and corresponding dynamic equations were established, ten-day soil moisture was calculated one by one, and process of drought was analysized according to the level of flood/drought in the various climatic regions. Results showed that the models could reliably monitor the dynamic changing trend of drought for agriculture of the various climatic zones in Gansu province. |