深圳河“8·29”特大暴雨及高水位成因分析

Cause analysis on“8·29”torrential rainfall and high water level in Shenzhen River

研究深圳河干流雨量量级相同时河道水位偏高原因,可为深圳河防洪决策提供技术支持。根据2018年8月28~30日深圳河流域降雨资料,选取深圳河干流罗湖、梧桐河、鹿丹村、深圳河口等站点的水位及流量特征资料,分析了该场洪水的降雨特性、洪水特征,并与2008年6月相同降雨量级形成的洪水进行对比分析。结果表明:虽然2008,2018年降雨量级相同,但受河道淤积、河道边滩范围扩大且植物生长、河口泄洪阻力增大和海平面上升等影响,2018年8月降雨致使河道水位明显偏高。同时深圳河流域呈扇形分布,平原河、梧桐河、布吉河等支流洪水易在鹿丹村附近汇聚,使得深圳河干流,尤其是鹿丹村一带河段面临严重的洪水威胁,该区域成为深圳河干流的防洪重点区域。

Finding out reasons that the water levels were higher in the main stream of Shenzhen River when the rainfall magnitude was same as before could provide support for flood control decision-making of Shenzhen River.On the basis of the rainfall data of the Shenzhen River Basin on August 28 to 30,2018(“8·29”torrential rainfall),we selected the water levels and flow characteristics data of Luohu,Wutong River,Ludancun,Shenzhen Estuary and other stations on the main stream of the Shenzhen River to analyze rainfall and flood characteristics of“8·29”torrential rainfall and compared them with the flood under the same rainfall level in June 2008.The results showed that the river water level in“8·29”torrential rainfall was significantly higher than that in 2008,even though the rainfall level in 2008 was the same as 2018.This was caused by river channel sedimentation,the expansion of the river beach and the growth of emergent plants,as well as increase of the estuary flood discharge resistance and the rise of sea level.Also,the Shenzhen river valley was distributed in a fan shape,so flood of some tributaries such as Pingyuan River,Wutong River and Buji River tended to converge near Ludancun,which made the main stream of Shenzhen River face serious flood threat,especially the river section near Ludancun,where has become a key point for flood control in the main stream of Shenzhen River.