Climatic change characteristics in the latest 52 years in Luan River Basin

On the basis of the meteorological data from 34 meteorological stations from 1957 to 2008,the long-term trend of major climatic variables was analyzed by using M-K test method.The results showed that the annual precipitation showed a decreasing trend especially in summer.The annual air temperature experienced a significant increasing tendency,especially in winter and spring,while the annual sunshine hours exhibited a significant decreasing tendency.The mean annual relative humidity showed a slight decreasing trend,and there was a decreasing trend in summer while a increasing trend in winter.The results also showed that the Kendall slopes of precipitation,air temperature,sunshine hours and relative humidity were-12 mm/10a,0.31 ℃/10a,6.8 h/a and-0.11%/10a,respectively during the past 52 years.