Recent Erosion and Deposition Patterns and Countermeasures for Flood Control in Shenzhen River.

Autor: FENG Zhi-yong, WU Yong-yan, WANG Lei, YIN Zhi, ZHANG Guang-yue, TAN Guang-ming
Předmět:
Zdroj: China Rural Water & Hydropower; 2022, Issue 5, p24-30, 7p
Abstrakt: The channel morphology and flood control capacity of Shenzhen River have changed significantly in the past decades owing to the Shenzhen River Regulation Project and river basin urbanization. Based on measured water, sediment, and bathymetric data, this paper systematically analyzes the recent erosion and deposition patterns of Shenzhen River and the changes of flood control capacity in Shenzhen River and its back-siltation characteristics after the implementation of different channel dredging schemes is explored by using a two-dimensional numerical model of flow and sediment. The results show that significant back-siltation occurred in Shenzhen River during 2007-2017, with an accumulated deposition volume of 74.6x104 m³. The morphological changes featured alternate channel erosion and deposition and consistent shoal deposition, with the magnitude of erosion and deposition gradually decreased from the upstream to the downstream. The reduced sediment transport capacity after the implementation of the Shenzhen River Regulation Project was the main reason of recent rapid deposition in Shenzhen River, and the deposition rate was associated with the flood tide discharge at the river mouth and the upstream sediment load. The flood control capacity of Shenzhen River decreased owing to channel deposition, the proportion of river section on the sides of Shenzhen and Hong Kong that currently meet the 50-year return period of flood control capacity are 63.2% and 56.8% respectively. Modeling results show that the improvement extent of flood control capacity of different channel dredging schemes is positively correlated with their back-siltation amount. The optimization suggestion for the improvement scheme of the flood control capacity of Shenzhen River is therefore given from the view of benefits of flood control and economic costs. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index