Change of flood morphological characteristics and its influencing factor over the river network plain region
The morphological characteristics of floods are important indicators for flood prevention and control,and have important indicative significance.Traditional hydrological studies mainly focus on the change of characteristics in flood magnitude under the changing environment,and the characteristics and mechanism of changes in flood morphological parameters under the influence of urbanization and climate change remain to be further explored.Taking the highly urbanized river network area of the Taihu plain as a typical example,this paper proposed a process-based method to identify flood events,and revealed the change in flood morphological characteristics and its driving mechanisms between 1971 and 2020.The results show that not only the flood magnitude(peak water level and water level increment)but also the morphological characteristics of flood fluctuation(such as rate of rising limb and recession)have changed significantly in the Taihu plain under the background of changing environment.Impervious area has a non-linear effect on the flood morphological characteristics.In the study area,the stations with significant breakpoint for peak water level occupy 61.5％,and 76.9％stations showed a significant upward trend.46.2％of the stations have a significant breakpoint for rate of rising limb,and all stations showed an increasing trend,among which,38.5％of the stations reach the significance level.A total of 53.8％of the stations have significant mutation and significant trends of recession rate,and the recession rate reaches 0.628 mm·d-1·a-1 in the whole period in the study area(p＜0.05).The antecedent water level conditions and rainfall characteristics are the main driving factors affecting the flood morphological pattern in the river network area of the Taihu plain.The results of this study could deepen the understanding of flood evolution in the Taihu plain region under a changing environment,and provide reference and support for flood disaster prevention and controlin similar plain river network areas.
flood morphological characteristicsexplainable machine learningchanging environmenturbanizationriver network plain region
万方数据
维普
