The Analysis Of Spatial And Temporal Characteristics Of Climate Change In Yangtze River Basin During 1970-2014

Climate change has far-reaching impact on global natural ecosystems and human society. Climate change has become the focus of governments and the scientific community and the general public of common concern in recent years. The Yangtze river is not only an important growth pole in the social and economic development of our country, but also the main commodity grain base in our country, in the social and economic development of our country in a very important position.This paper selects 131 meteorological stations in the Yangtze River Basin and use the Mann-Kendall nonparametric test, principal component analysis and R/S analysis to study the spatial and temporal variation of meteorological indicators of Yangtze River Basin.The main conclusions are as follows:(1)The average temperature was a significant increase in the trend, and the basin average temperature increased by a big margin of season mainly in spring and autumn, winter and summer followingfrom1970 to2014. The main index showed that warm main index showed a tendency to increase, cold index showed a downward trend. Except two indices, the annual mean of the diurnal temperaturerange(DTR)and warm nights(TN90, the remaining 10 indicators showed point mutation.(2)The heat resources of ?0?, ?5? and ?10?significantly increasing trend in the Yangtze River Basin from 1970–2014. Three climate zones mutation occurred in the 1990 s, the starting days, end days and durationwere advanced, pushed back and extend the trend heat resource conditions showed a significant increasing trend.(3)The result shows that, Consecutive Dry Days(CDD), Max1-day Precipitation Amount(Rx1day)(P<0.05), Very Wet Days precipitation(R95P), Very Wet Days(R95),Extremely Wet Days(R99), Extremely Wet Days(R99P) of Rainfall, Simple Daily Intensity Index(SDII)(P<0.05) showed a trend of increase, While other extreme precipitation indices showed a trend of decrease during 1970-2014.Heavy rain in the Taihu Lake Basin, the most part Poyang Lake Basin and the downstream area of Dongting Lake region faces the increased heavy precipitation, while the centre of Hanjiang basin and the south of the Min River and Tuo River showed a downward trend.(4)The trend of potential evapotranspiration increased significantlyfrom1970-2014. Only a few stations showing decrease in Yangtze RiverBasin. Decreaseing areas mainly aggregated in parts of the upper reaches of the Jinsha RiverBasin and the Min-TuoRiverBasin. The number of increasing stations of the potential evapotranspiration in spring and autumn were more. The wet and aridity condition in spring and autumn presented down in Yangtze riverBasin region during 1970-2014. The number drop stations in spring, autumn and winter more than summer.