Abstract: Based on the 1960-2008 meteorological and hydrological data in the upper and middle reaches of Heihe River basin, and by the methods of linear regression, nonparametric MannKendall test, accumulative anomaly, annual accumulation, and change rate of accumulation slope, this paper analyzed the variations and trends of the runoff and climate in this region, and calculated the contribution rates of climate change and human activity on the runoff. In the upper reaches of Heihe River basin, the annual runoff, precipitation, and evaporation presented an overall increasing trend, with a significant increase of the annual runoff and evaporation. In the midstream, the annual runoff and evaporation exhibited a decreasing trend while the annual precipitation was in adverse, but the trends were not obvious. The abrupt change year of the runoff in the upper and middle reaches was 1979 and 1984, respectively. According to the abrupt change year of runoff, the time series were divided into upstream (1960-1979 and 1980-2008) and midstream (1960-1984 and 1985-2008), and the linear equations of the accumulated runoff, accumulative precipitation, and accumulative evaporation and the time series were obtained. In the upstream, climate change played dominant role, human activity had lesser effects, and their contribution rates to the increase of runoff were 59.71% and 40.29%, respectively. In the midstream, the effects of climate change on runoff were lesser, while human activity played dominant role, with their contribution rates to the decrease of runoff being 25.23% and 74.77%, respectively. This study could provide a guide for the future water resources development and utilization in Heihe River basin.  

Key words: p-hydroxy benzoic acid, cinnamic acid, continuous cropping obstacle, peanut, soil available nutrients,  , soil enzyme, yield.