Using L-moments Approach to Conduct Regional Flood Frequency and Associated Spatial Patterns Analysis in the Pearl River Delta Region

Abstract

The Pearl River Delta (PRD) has one of the most complicated deltaic drainage systems with probably the highest density of crisscross-river network in the world. In this study, the index flood L-moments approach is applied to the regional flood analysis and detection of spatial behaviors in the PRD region. Results indicate that: (1) the whole PRD region is definitely heterogeneous according to the heterogeneity test and can be divided into 3 homogeneous regions; (2) The spatial maps of annual maximum flood stage corresponding to different return periods in the PRD region suggest that the flood stage decreases gradually from the riverine system to the costal areas; (3) From a regional perspective, the spatial patterns of flood variations imply that the coastal region is most likely to suffer extraordinary flood hazards and catastrophes. While extreme rainfall in the upstream basins may lead to moderate flood risks in the upper and middle PRD region. The rest parts are identified as the lowest flood risk area. These findings will contribute to formulating the regional development strategies for policymakers and stakeholders in water resource management against the menaces of frequently emerging floods and well-evidenced sea level rising.