Climate change characteristics and its effect on ecological environment from 1971 to 2009 in the Jinsha river valley of Yunnan province

Based on the mean monthly air temperature, precipitation and evaporation of 35 weather stations along the Jinsha river valley of Yunnan province from 1971 to 2009, meteorological elements changes and their trends were analyzed in the upper, middle and lower reaches of the Jinsha river valley in Yunnan Province. The results show that the mean annual air temperature increases in recent 40 years with 0.29 ℃/10 a in the study valley. In the middle reaches of the Jinsha river valley, the mean annual air temperature is higher and its trend is 0.46 ℃/10 a, while it is lower in the upper reaches and has less change. The mean annual precipitation increases by 8.89 mm/10 a in the Jinsha river valley, and it is the highest in spring. It increases in the upper and middle reaches, while it decreases in the lower reaches. Inter-annual change trends of various meteorological elements are not significant. The effects of climate change on the natural ecosystem, water resource, and natural disaster and so on are significant, which intensify vulnerability of ecosystem in the valley and influence the local economic development to some extent.