华北和印度夏季风降水变化的对比分析

 利用华北和印度夏季降水资料，采用趋势分析、小波变换等方法，对两地区夏季风降水进行了对比分析。结果表明：1) 华北和印度夏季风降水量都存在线性减少倾向，但华北更为显著，减少达16 mm/10 a；2) 华北和印度夏季风降水变化都以18 a周期为主，近年都有逐渐缩短的趋势，而印度的这种周期缩短得比华北更快，近年降水变化周期接近15 a；3) 华北和印度夏季风降水变化在1956、1976、1992/1993年发生了趋势转折；4) 华北和印度降水量主要集中在6-9月，夏季风降水特征非常明显，但两地变化特征表现不尽相同。

Comparison of Summer Monsoon Rainfall Changes Between North China and India

Based on summer precipitation data,by using trend analysis,wavelet transform methods,the changes of summer rainfall in North China and in India were analyzed. The results show that the summer monsoon rainfall has obviously linear decreasing tendency both in North China and in India,it is more obvious in North China than in India,with an average decreasing trend of 16 mm/10a in North China during the past 56 years and 2 mm/10a in India,respectively. The change of rainfall has a dominant 18-year period both in North China and in India. Turning of rainfall change occurred in 1956,1976 and 1992/1993. The precipitation mostly occurred from June to September in two regions,but their changes were not the same. In North China,the rainfall appeared a rapid enhancement in July,and an abrupt decrease in September. However,in India,the rainfall appeared a rapid enhancement in June and an abrupt decrease in October.