河南省引黄受水区极端降水时空演变及变异特征分析OA

The aim of this study is to reveal the evolutionary patterns of extreme precipitation in the Yellow River Water Receiving Area of Henan Province,to scientifically understand the risks of flood and drought disasters at the regional scale,and to provide a scientific basis for water resources allocation and for disaster prevention and mitigation in the water receiving area.Based on daily precipitation data from 20 me-teorological stations during 1973-2022,eight extreme precipitation indices were calculated using the RClimDex model,and analyzed via the Mann-Kendall trend test,Morlet wavelet analysis,and Range of Variability Approach(RVA).This study systematically analyzed the spatio-temporal evolution characteristics,periodic variation patterns,and the degree of variability of extreme precipitation indices in the region.The results show that:Seven precipitation indices,including annual precipitation,increase from northwest to southeast,while the consecutive dry days index shows an opposite distribution,indicating a higher drought risk in the northwestern region.All indices exhibit no significant linear trends and are mainly characterized by strong interannual fluctuations,with extreme value indices fluctuating drastically and the suddenness of extreme precipitation becoming highly significant after the abrupt change in 2010.A long-period evolution characteristic of 15-17 years ex-ists during the study period.The region is currently in a relatively wet season,suggesting relatively high precipitation and a frequent trend of extreme events in the near future.The variation degrees of extreme value indices are significantly higher than those of total amount indices.Among them,the maximum 1-day precipitation is the only index reaching a moderate degree of variation,indicating that regional climate risks mainly stem from the enhanced suddenness of single-day extreme heavy precipitation.