地面沉降对永定河中下游防洪安全影响分析

The impact of ground settlement on the flood control in middle and lower reaches of Yongding River

地面沉降是我国平原地区的重要地质灾害之一,严重的地面沉降使堤防、闸等防洪工程设施同步下沉。永定河流域地面沉降主要分布在中下游地区,该地区的地面沉降降低了永定河流域防洪工程的防洪、防潮标准,削弱了防灾功能,直接影响天津市和河北省广大地区的防洪安全。为分析地面沉降对永定河系行洪安全影响,本文通过对不同时期测量基准点资料及地形图资料进行比对,分析永定河中下游地区沉降趋势,并采用一、二维嵌套的非恒定流洪水演进数学模型,对永定河泛区行洪能力进行复核。

Ground subsidence is one of the important geological disasters in the plain areas of China. The serious ground subsidence makes the flood control works such as levees and sluices settle synchronously.The ground subsidence of the Yongding River is mainly distributed in the middle and lower reaches, which has reduced the project standard of protection against floods and tides in the Yongding River, weakened the hazard resistant function, and directly influenced the safety of large areas of Tianjin and Hebei province. In order to analyze the impact of ground settlement on the safety of flood discharge in the Yongding River, this paper studies the settlement tendency of the middle and lower reaches of the Yongding River through comparison of the survey reference points in different periods and topographic maps, and checks the flood-carrying capacity in the floodplain of the Yongding Rriver with one-dimensional and two-dimensional nested unsteady flow flood routing mathematical model.