Characteristics of Climate Change in Huolin River Basin, Inner Mongolia,1951-2010

Based on monthly mean air temperature and monthly precipitation data from nine meteorological stations in Huolin River basin from 1951to 2010,using climatic linear trend,Mann-Kendall test and correlation analysis methods,the spatialtemporal characteristics of climatic change in this region were analyzed in this paper.The results indicated that the annual temperature had increased 2.3 ℃,with an increasing rate of 0.38 ℃·(10a)-1,showing an upward trend in general from 1951to 2010in the basin.The increase of temperature in spring was most obvious,with a changing rate of 0.50 ℃·(10a)-1.The annual mean temperature had an abrupt change mainly in 1986,and the temperature averaged from 1987to 2010 was more than 1.3 ℃ higher than that from 1951to 1986.There were significant cyclical changes with 6～8and 15aperiod.Annual precipitation had fallen 83.9 mm,with a decreasing rate of 13.98 mm·(10a)-1 and a downward trend in general from 1951to 2010.The decrease of precipitation was most pronounced in summer,with a decreasing rate of 11.41mm·(10a)-1.Annual precipitation abrupt was mainly observed in 1998,and the precipitation averaged from 1998to 2010 was 76 mm less than that from 1951to 1997.There were significant cyclical changes with 4years and 8～9 years periods.It is found that the change in temperature has positive correlation with AO index and the change in precipitation negatively correlates with EAP index.