1998年长江流域特大洪水的降水分析

ANALYSIS OF PRECIPITATION DURING THE 1998 CATASTROPHIC DELUGE IN THE CHANGJIANG RIVER BASIN

利用长江流域 ( 1 0 2°E以东 ) 1 2 5个站的实测降水资料 ,分析了 1 998年夏季长江流域降水的时空分布和气候统计特征 ,并与历史同期进行了比较 ,特别是和 1 931、1 954年等特大洪水年份进行了较全面的对比 .结果表明 ,1 998年夏季长江流域的强降水主要分为 4个时段 ;总降水量的分布成不对称的鞍型场 ;上、中、下游地区异常频繁的、特别集中的强降水是造成长江持续高水位和特大洪涝灾害的最主要原因 .

WT5BZ]By using the precipitation data of 125 stations in the Changjiang River basin, the temporal and spatial distribution characteristics and climatological statistic characteristics of precipitation in the summer of 1998 are analyzed. Comparison is conducted with the previous data for the same period, especially with the data of deluge years such as 1931 and 1954. The results show that the precipitation process in the summer of 1998 includes four stages. The distribution pattern of total precipitation appeared to be an asymmetry saddle. The abnormally frequent and concentrated severe precipitation in the upper, middle and lower reaches is the most important cause of the continued high water level and catastrophic deluge of the Changjiang River.[WT5BZ] [WT5HZ]