大渡河中下游洪水过程时空演变规律研究

Study on Spatio-Temporal Evolution of Flood Process in Dadu River

近年来在气候变化和人类活动等因素综合影响下,大渡河流域洪水过程的时空分布特征发生了变化。本文以沙坪站为代表,分析了1937~2019年大渡河中下游历次洪水的洪峰、洪量、峰现时间等特征,利用线性回归、滑动平均、小波分解、Moving-T检验、Mann-Kendall检验和Morlet小波分析,对洪水过程的趋势、突变与周期等特征进行了全面分析。结果表明,大渡河中下游洪水洪峰与洪量时间序列均呈现显著的减小趋势,年最大洪峰出现时间有明显的前移倾向,洪峰、洪量突变时间主要集中于20世纪50~60年代,峰现时间没有明显的突变年份,5个洪水过程评价指标的第一主周期为24年左右。

In recent years,under the comprehensive influence of climate change and human activities,the spatial and temporal distribution characteristics of the flood process in Dadu River Basin have changed.Taking Shaping Station as the representative,this paper analyzes the characteristics of the flood peak,flood volume and peak occurrence time of the previous floods in the middle and lower reaches of Dadu River from 1937 to 2019,and makes a comprehensive analysis of the characteristics of the flood process,such as trend,mutation and period,by using linear regression,sliding average,wavelet decomposition,moving-T test,Mann-Kendall test and Morlet wavelet analysis.Results show that the middle and lower reaches of dadu river flood peak flow and tend to significantly reduce the time of the actual sequence,annual maximum flood peak time has obvious tendency of forward,flood peak,the mutation of the actual time mainly concentrated in the 1950 s and 1960 s,the peak time now there was no significant mutation of the year,five evaluation index of the first main flood process cycle for 24 years.