巢湖流域雨涝时空特征分析

Analysis of the Spatial--Temporal Characteristics of Waterlogging in Chaohu Basin

利用巢湖流域7个国家气象站1961~2016年逐日降水量资料,用频率分析、Pearson-Ⅲ型分布曲线、趋势分析和滑动平均等方法分析了近56a来巢湖流域雨涝的时空分布特征和变化规律。结果表明,（1）巢湖流域4个子单元的年最大日降水量的月际变化均表现为典型的正态分布;用Pearson-Ⅲ型分布曲线拟合巢湖流域各子单元年最大日降水量的分布,得出5a、10a、20a、50a等4个重现期下日降雨量,并且呈自南向北减小的特点。（2）巢湖流域4个子单元均遭受过雨涝,流域雨涝频率从东南向西北减少;季节分布上,夏季是巢湖流域雨涝灾害频率最高、范围最广的季节,秋季多于春季,冬季没有出现过雨涝;各子单元雨涝最集中的季节都是夏季,均达到或超过15%。（3）巢湖流域雨涝站率气候趋势为0.79/10年,但呈现比较明显的分段年代际演变特征,第一阶段从1960年代中期到1980年代为明显增加趋势,其中1980年代中期达到峰值,第二阶段从1990年代到2010年代为不明显增加趋势。

Based on the Daily precipitation data of 7 national weather stations in Chaohu Basin during 1961 to 2000, the Pearson--Ⅲ distribution curve, trend analysis and moving average method were used to analyze the temporal and spatial distribution characteristics and change rules of waterlogging. The main results were summarized as follows：（1） Monthly variation of annual maximum daily precipitation in 4 sub units of Chaohu River Basin shows a typical normal distribution. The distribution of annual maximum daily precipitation in each sub unit of Chaohu River Basin is fitted by Pearson-Ⅲ distribution curve. The daily rainfall of 4 recurrence periods, such as 5a, 10a, 20a, 50a and so on, is calculated, which showed the cha-racteristics of decreasing from south to north.（2） 4 sub--units of Chaohu Basin are subjected to waterlog-ging, and the frequency of waterlogging decreases from southeast to northwest. As for the seasonal fea-tures of distribution, the period when waterlogging disaster occurs with the highest frequency, and the widest range of Chaohu Basin is in summer. In addition, there was no waterlogging disaster happened in winter before, while more disasters occurred in autumn than spring. Summer is the most centralized season of water logging disaster in various subunits, and the rate has reached or exceeded 15%. Summer is the most concentrated season of waterlogging in each sub unit, which had reached or exceeded 15%.（3） The climate trends rate of waterlogging in Chaohu Basin is 0.79/10 years, which shows obvious cha-racteristics of decadal evolution. It shows an obvious increasing trend in the first stage from the middle of 1960s to 1980s, which reaches the peak in the mid--1980 s, and the second stage from 1990s to 2010s is not significantly increased.