Investigation on flood event variations at space and time scales in the Huaihe River Basin of China using flood behavior classification

Abstract

Flood is one of the severest natural disasters in the world and has caused enormous causalities and property losses. Previous studies usually focus on flood magnitude and occurrence time at event scale, which are insufficient to contain entire behavior characteristics of flood events. In our study, nine behavior metrics in five categories (e.g., magnitude, duration, timing, rates of changes and variability) are adopted to fully describe a flood event. Regional and interannual variations of representative flood classes are investigated based on behavior similarity classification of numerous events. Contributions of geography, land use, hydrometeorology and human regulation on these variations are explored by rank analysis method. Results show that: five representative classes are identified, namely, conventional events (Class 1, 61.7% of the total), low discharge events with multiple peaks (Class 2, 5.3%), low discharge events with low rates of changes (Class 3, 18.1%), low discharge events with high rates of changes (Class 4, 10.8%) and high discharge events with long durations (Class 5, 4.1%). Classes 1 and 3 are the major flood events and distributed across the whole region. Class 4 is mainly distributed in river sources, while Classes 2 and 5 are in the middle and down streams. Moreover, the flood class is most diverse in normal precipitation years (

Spatio-temporal accuracy evaluation of MSWEP daily precipitation over the Huaihe River Basin, China: A comparison study with representative satellite- and reanalysis-based products

“…The annual mean precipitation in the BB is approximately 920 mm, and it gradually decreases from south to north. Precipitation in the rainy season (June to September) accounts for 50%-75% of the total annual-precipitation (Zhang et al, 2020).…”

Analysis of Small and Medium–Scale River Flood Risk in Case of Exceeding Control Standard Floods Using Hydraulic Model

“…The flood will spread to the floodplain along the breach and inundate the depressions, which can be considered as the two-dimensional hydrodynamic evolution of flood in floodplain [4,9] The MIKE FLOOD model is used to combine the one-dimension model and two-dimension model to simulate the flood process in the floodplain. The results suggest that overflowing starts after 6 h in the four cases, and this time is taken as the starting point of outflow in floodplain and recorded as 0th hour.…”

“…Flood poses a serious threat to social security and economic development [1,2]. The riparian zone is generally densely populated and highly economically developed, while it is particularly susceptible to flooding [3,4]. To reduce the probability of flood disaster, structural measures such as dams and levees are extensively employed [5,6].…”

Understanding meteorological and physio-geographical controls of variability of flood event classes in China

“…Flood events usually show tremendous spatial and temporal variabilities in behavior due to heterogeneities in meteorological and underlying surface conditions over large basins or entire regions (e.g., county, continent and world) (Berger and Entekhabi, 2001). It is a huge effort and unrepresentative to investigate the flood change characteristics at event scale ( Tarasova et al, 2019;Zhang et al, 2020). Flood event similarity analysis is beneficial to investigate comprehensive dynamic characteristics of flood events in space and time by grouping massive homogeneous events into some manageable classes with significantly statistical differences of flood behaviors (e.g., great or small floods, fast or slow floods, rain or snowmelt floods) (Brunner, 2018).…”

“…The inductive approach directly focuses on the shape similarity of flood events by clustering the behavior characteristics extracted from the flood event hydrographs. The behavior characteristics include magnitude, frequency, duration, timing and seasonality, variability metrics, which are considered as the critical components to characterize the entire range of flood events (Poff et al, 1997;Kuentz et al, 2017;Zhang et al, 2020). The reported flood event classes are the fast events with steep rising and falling limbs, the slow events with both elongated rising and falling limbs, the sharp or fast flood event, the flash flood (Kuentz et al, 2017;Brunner et al, 2018;Zhai et al, 2021;Zhang et al, 2020).…”