Climate Change and Its Environmental Effects in the Surrounding Area of Qinghai Lake

Through quantitative analysis of annual mean temperature,annual precipitation,annual evaporation amount,wind speed,windy days,grassland change,lake transition and land desertification trend in recent 44 years in the surrounding area of Qinghai Lake,this paper reveals the effects of regional ecological environment resulted from climate change.1) During the last 44 years,annual and seasonal mean temperatures(at the speed of 0.262℃/10a) represent a trend of evident increase.Annual precipitation decreased 3.8% in the 1960s and 5.2% in the 1970s,but increased by 1.37mm/10a in the 1980s,reaching the average value in the 1990s and beginning of 21st century.Annual evaporation amounts in spring, summer and winter reduced with a rate of 66.53mm/10a.Average wind speed decreased with a rate of 0.01(m/s)/10a,while windy days decreased with a rate of 4.5 d/10a;2) The regional forage biomass and precipitation is positively correlated.Significant increase of temperature and strong variation of seasonal precipitation affected the forage's growth period,and posed a fluctuation of pasture biomass;3) Coverage area of water in Qinghai Lake is significantly negatively correlated with annual mean temperature and seasonal temperatures in autumn and winter,while positively correlated with water surface evaporation of the lake.During the 1960s and the 1970s,a positive correlation existed between water coverage area of the lake and spring precipitation.Since the 1990s,with the warming of climate,the temperature has been playing a dominant role on the impact of the water coverage area of Qinghai Lake;4) Warming and drying climate in the surrounding area of Qinghai Lake is the dominant factor that resulted in rapid development of desertification.