Flood Season Staging and Adjustment of Limited Water Level for a Multi-Purpose Reservoir

Chongxun Mo,Juan Deng,Shufeng Lai,Xingbi Lei,Guikai Sun,Yuli Ruan,Zhenxiang Xing

doi:10.3390/w14050775

Abstract

A reasonable flood season delineation can effectively implement staged reservoir scheduling and improve water resource efficiency. Therefore, this study is aimed at analyzing the flood period segmentation and optimizing the staged flood limit water levels (FLWLs) for a multi-purpose reservoir, the Longtan Reservoir, China. The rainfall seasonality index (SIP) and the runoff seasonality index (SIR) are used to evaluate the feasibility and rationality of the flood period staging. The fractal method is then used to segment the flood season. Finally, the design flood is carried out to optimize the staged FLWLs. The results show that the SI is an effective indicator for judging the feasibility and verifying the rationality of flood segmentation. The flood period can be segmented into the pre-flood season (12 April–29 May), the main flood season (30 May–3 September), and the post-flood season (4 September–9 November). The FLWLs in the main flood and the post-flood season can be raised by 2.05 m and 3.45 m, and the effective reservoir capacity is increased by 5.810 billion m3 and 6.337 billion m3, according to the results of the flood season division.

Highlights

Accepted: 24 February 2022The frequency of extreme flood events has increased significantly under the influence of global warming [1,2]
The results indicate that the SIP and the SIR show no clear tendency to increase or decrease, reflecting the random nature of hydrological phenomena
Fractal calculations based on the rainfall and runoff data of Longtan Reservoir from

Summary

Introduction

Accepted: 24 February 2022The frequency of extreme flood events has increased significantly under the influence of global warming [1,2]. Areas rich in water resources, but especially the region behind the economy is more vulnerable to the hazard of floods. Sustainability, resilience, and climate change adaptation flood control strategies have emerged [7], such as low impact development (LID) [8,9], sustainable drainage systems (SUDS) [10,11], green infrastructure (GI) [12–14], water sensitive urban design (WSUD) [15,16], etc., which have received positive responses in developed countries. For developing countries faced with population pressure and food shortages, forcing societies to use floodplains, engineering measures, such as dredging rivers, strengthening drainage systems, and building flood walls, continue to be taken to reduce the impact of flooding [17–19]. Reservoirs are one of the most effective components of critical infrastructure [20], but traditional reservoir operation and scheduling often use a single

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Discussion

Conclusion