Impact Of Climate Change And Human Activity On Water Resources In The Heihe River Basin

Heihe River is located in the northwest arid area in China, with climate drought, fragile ecological environment and water shortage. With human production capacity improving and industry and agriculture rapidly developing, water resources have become an important factor which restricts economic development and impacts ecological environment stabilization in the basin. Currently, there have been many researches about impacts of climate change and human activities on water resources, but most are focused on qualitative research, lacking of quantitative evaluation. How to identify influence degree of climate change and human activities on water resources, by quantifying their weight coefficient, to analysis the main factors of water resources has some research significance for sustainable use of water resources and making rational water management policy.Based on precipitation and temperature monitoring data of Qilian, Yeniugou, Gaotai, Zhangye, Sunan, Shandan and Minle weather stations from 1956 to 2005, runoff data of Yingluoxia and Zhengyixia hydrological stations from 1956 to 2005, and national economic statistic data of middle reaches of the Heihe River from 1976 to 2005, and adopt regression analysis, residual mass curve, and Man-kendall method to analyze in the climate change and human activities characteristics of Heihe River which may provide a good reference for selecting correlation indicators. So weight coefficient are calculated by using combination weighting method. The results show that:both annual precipitation and annual mean temperature of upper and middle reaches of Heihe River present an increasing trend, especially entering the 90s the increasing trend are more significant; furthermore, based on this trend, analyzing impacts of climate change on hydrology and water resources, annual precipitation has a large correlation to annual runoff of Heihe River Basin, which may refer to that precipitation is the main supply sources to runoff in arid area; using regression analysis to analyze development trend, which shows that human activities indicators are increasing significantly, leading to water consumption increasing in the middle reaches of Heihe River. For the middle reaches of Heihe River basin, human activities are the main factors on affecting water resources, and its weight coefficient reach 66.63% which is higher than the factors of climate change whose cumulative weight coefficient is 33.37%. Analyzing main reasons, with population growing, industrial and agricultural output value improving, production and domestic water demand increasing, and lacking of effective management during the process of using, which leads to a series of water problems so that water resources imbalance between supply and demand is becoming increasingly prominent in the middle reaches of Heihe River.