太湖流域降水量年内分配不均匀性分析

Intra-annual Inhomogeneity Analysis of Precipitation in Taihu Lake Basin

利用太湖流域106个代表雨量站的1951-2010年的逐日降水资料,通过计算降水集中度和集中期,讨论了流域降水量的年内分配不均匀分布特征。结果表明,太湖流域的降水集中度和集中期变化过程相似,均具有自北向南递减的变化特点,从长期趋势看,各分区降水集中度均呈减小趋势,集中期的变化趋势有增有减,但这两种变化趋势均不显著。年降水量与降水集中度和集中期的相关系数表明,太湖流域年降水量与降水集中度呈中度正相关,即年降水量越多（少）,年内降水越集中（均匀）;年降水量与降水集中期相关系数在空间上也呈正相关,但相关程度整体上不如年降水量与降水集中度的相关程度,典型时段降水量与降水集中度关系密切。

Based on the daily precipitation data at 106 representative stations in Taihu Lake Basin from 1951 to 2010, the features of precipitation were analyzed by using the definitions of precipitation concentration degree （PcD） and precipitation concentration period （PcP）. The results show that the change processes of PCD and PcP in Taihu Lake Basin are similar, which both decrease from north to south. In view of the long-term change, the PCD of all districts appears the decreasing trend. But the change process of Pcp is inconsistent, which has trends of increasing and decreasing. However, the change processes of PCD and Pce do not display the obvious trend. It is also found that the annual amount of precipita- tion has moderate positive correlation with PcD, that is to say, the more （less） annual precipitation is, the bigger （smaller） the PCD is. The relationship between annual precipitation and PcP is also the positively correlated in space, but the degree of which is not as good as the degree of annual precipitation and PeP. The typical periods of precipitation have close relationships with PCD.