沅水流域强降水面雨量及来水量特征分析

The Analysis of the Characteristics of the Heavy Rainfall and Inflow on the Surface in Yuanshui River

基于2000—2017年沅水流域41个国家气象观测站逐日08:00—08:00降水数据及1980—2017年凤滩水库逐月/年平均来水量数据,利用算术平均法、Mann-Kendall趋势分析法和突变检验法对沅水流域7个子流域逐日面雨量的强降水频次分布、极值分布及凤滩水库1980—2017年来水量、降水量的时间变化序列进行检验分析。结果表明:沅水7大子流域强降水面雨量的频次具有明显的月分布变化,5—6月出现的频次最多,7月次之,1月强降水频次出现最少,仅为21次;凌津滩流域强降水日面雨量出现频次最高,碗米坡流域次之,三板溪流域最少,4—10月为强降水集中期;碗米坡流域月平均面雨量和凤滩水库月平均来水量相关性极高,变化规律基本一致。利用5 a滑动平均、Mann-Kendall趋势分析法和突变检验法对凤滩水库1980—2017年来水量、降水量的时间变化序列的检验分析以及UF和UB曲线中的统计量显示,两者的变化趋势都是减少的,且降水量的减少趋势显著。

Based on the daily precipitation data of 41 national meteorological observation stations in Yuanshui basin from 2000 to 2017 and the monthly/annual average inflow data of Fengtan reservoir from 1980 to 2017,using the arithmetic average method,Mann-Kendall trend analysis method and mutation test method were and analyzing the frequency distribution and extreme value distribution of daily precipitation in seven sub basins of Yuanshui basin,and the time series of water quantity and precipitation in Fengtan reservoir from 1980 to 2017.The results show that the frequency of heavy rainfall in 7 sub basins of Yuanshui has obvious monthly distribution change,the frequency of heavy rainfall is the most from May to June,followed by July,and the frequency of heavy rainfall in January is the least,only 21 times.Among them,the frequency of daily heavy rainfall in Lingjintan basin is the highest,followed by that in Wanmipo basin,and that in Sanbanxi basin is the lowest.April October is the period of heavy rainfall concen⁃tration.The monthly average areal rainfall in Wanmipo basin is highly correlated with the monthly average inflow of Fengtan reservoir,and the variation law is basically the same.The test and analysis of the time series of water quanti⁃ty and precipitation in Fengtan reservoir from 1980 to 2017 and the statistics in the UF and UB curves by using the 5 a moving average,Mann Kendall trend analysis method and mutation test method show that the trend of both chang⁃es is decreasing,and the trend of precipitation reduction is significant.