长江流域上游干旱特征分析

Analysis of Drought Characteristics in the Upper Reaches of the Yangtze River Basin

为分析长江流域上游干旱特征,利用1961年1月至2012年12月长江上游共69个气象站的气象数据资料,以帕尔默干旱指数(PDSI)为主要指标对长江上游流域的干旱强度、干旱持续时间、干旱频率等干旱特征进行比较分析。结果表明,长江上游区域PDSI的月际变化较大,旱涝期交替出现,同时年代干旱最强值呈现先减弱后增强的趋势,并在2006年达到干旱强度最强值;干旱持续时间较长的干旱事件主要发生在1960、1970年代,平均干旱持续月数为4.2个月;上游干旱频率主要以初始干旱为主,其中年际干旱集中在1960年代末期至1970年代初期和2000年代后期两个阶段,季节干旱主要发生在冬季。研究成果可为长江流域上游的干旱治理提供参考。

By using meteorological data from January 1961 to December 2012 of 69 meteorologic stations,and taking the Palmer Drought Severity Index(PDSI)as the main criterion,this paper analyzed the characteristics of intensity,duration and frequency of droughts for the upper reaches of the Yangtze River basin.The results show that the monthly PDSI in the upper reaches of the Yangtze River changed remarkable in each month between drought and floods,and the strongest value of the drought appears the trend of weakening in the strengthening,and reached the strongest value in2006.The long duration drought events mainly occurred in the 1960 sand 1970 s,and the average drought duration was4.2 months.The frequency of drought in the upper reaches dominated by initial drought in the late 1960 sto 1970 searly and the late 2000 s,while the seasonal drought mainly happened in winter.The research results can provide reference for drought management in the upper reaches of the Yangtze River Basin.