城市化对长江三角洲地区降水变化趋势影响初探

Urbanization impact on precipitation change trend in the Yangtze River Delta

根据长江三角洲地区城市化程度,选择1956—2007年和城市化发展较为迅速的1981—2007年两个时段进行研究,基于长江三角洲地区35个国家基本/基准站1956—2007年52a日降水量资料,分析了两个时段长江三角洲降水量的年和季节变化特征、降水的气候趋势系数和气候倾向率的空间分布差异,以及城市化对降水变化趋势的影响。初步的研究结果表明:1956—2007年长三角地区年降水呈减少趋势,城市化快速期减少趋势明显加快。两时期季节降水量有相同的变化趋势,但变化趋势明显程度和变化速率差别很大,城市化快速期变化剧烈,年降水变化趋势在城市化快速期几乎呈现出与整个52a时段相反的空间分布,城市化快速期长江三角洲中部大片区域变干趋势显著。

Based on the degree of urbanization selected, one is from 1956 to 2007, the other of the Yangtze River Delta, two kinds of periods are is from 1981 to 2007, during which the urbanization is rather rapid. It is analyzed that annual and seasonal precipitation characteristics, spatial distribution difference of precipitation trend coefficient and climate tendency rate, and the impact of urbanization on precipitation, based on the 52 years daily precipitation data from 35 national basic/reference meteorological stations. Preliminary studies suggest that the annual precipitation in the Yangtze River Delta has a decreasing tendency in the whole period（1956--2007）, while it has an obvious reduction during the rapid urbanization. The seasonal precipitation of the two periods has similar trend but they had great difference in change rate, which changes more severe in the rapid urbanization period. The distribution of annual precipitation trends in the rapid urbanization period is almost contrary to that in the 52 years, which means that large areas of the central Yangtze River Delta has the obvious trend to become dry.