华南地区河道边滩植物阻力特性研究——以深圳河为例

Resistance Characteristics of Riparian Plants in South China:A Case Study of Shenzhen River

河道边滩植物的阻水特性是影响河道行洪能力的重要因素。以深圳河为例,利用遥感影像解析2008—2018年间河道边滩植物生长范围变化,基于实测洪水资料和一维数学模型,通过设置不同河道综合糙率的研究组合,定量分析边滩挺水植物对河道断面综合糙率的影响,进而研究边滩挺水植物对河道洪水流速和洪水位的影响程度。研究发现:2008—2018年,深圳河中下游边滩植物在向河道内扩展了近30 m,河道综合糙率增大约0.005,在200、100、50年一遇洪水条件下河道水位分别增加1.1、0.7、0.5 m。

The water-blocking characteristics of riparian plants are an important factor affecting the flood discharge capacity of the river.Taking the Shenzhen River as an instance,this paper adopts image analysis remote sensing to analyze the changes in the growth range of riparian plants from 2008 to 2018.Based on the measured flood data and a one-dimensional mathematical model,research combinations of different channel composite roughness are set to quantitatively analyze the influence of the riparian plants on the composite roughness of the river section and then study the degree of influence of riparian plants on flood flow velocity and flood stage.The study shows that from 2008 to 2018,the riparian plants in the middle and lower reaches of the Shenzhen River expanded by nearly 30 m into the river channel.The composite roughness of the river channel increased by about 0.005.In flood conditions of once in 200,100,and 50 years,the water level of the river channel increased by 1.1 m,0.7 m,and 0.5 m,respectively.