| Using the data of 171 observations from 1961 to 2003 in Northwest China, the paper analyzes the impact of precipitation resources vacillation on agriculture in Northwest China. The results show that the annual precipitation and the precipitation in the growing season of overwintering crops, spring wheat and autumn crops was increased in the west part but decreased in the east part during 19872003 compared to that during 19611986, with Yellow River as the rough line of demarcation. The precipitation, flood frequency and available water resources in the west part tended to be increased, causing a positive impact on agriculture; while the precipitation in the east part tended to be decreased, causing the increase of drought occurrence and a negative impact on agriculture. The precipitation in winter was generally increased in Northwest China, being beneficial to soil moisture conservation, safe overwintering of crops and spring sowing, but increasing the hazard of snow disaster in pastoral areas and affected the safe overwintering of animals. |