南水北调中线工程地下水排水数值模拟研究

Study on numerical simulation of groundwater drainage in the middle route of South-to-North Water Transfer Project

基于南水北调中线一期工程地下水排水设计及其渠道与地下水之间的相互关系,本次研究选取中线工程磁县渠段,建立了研究区三维水文地质结构模型及其内排段地下水向渠道排水的三维数值模型,针对地下水水位动态变化条件下地下水向渠道的水量转化规律进行了定量模拟研究。结果表明:参照中线工程设计排水能力,地下水排水量将畅通排入渠道,确保中线工程渠道的安全稳定运行;地下水向渠道的排水主要受渠段区域水文地质条件和地下水水位变化等因素的影响;在满足排水条件的情况下,从空间角度而言,与南水北调中线工程相关含水层位存在向渠道的排水量,从时间角度而言,排水过程与研究区潜水水位的年内动态相符合。

Cixian section of the main canal was selected as a case study of the middle route of South-to-North Water Transfer Project（SNWT）,based on groundwater drainage design and exchange between canal water and groundwater.A three-dimensional hydrogeologic architecture model of the study area and a three-dimensional numerical model of groundwater flow into the canal with interior drainage were developed to analyze the water exchange under groundwater table fluctuations.Results show that in the design conditions of groundwater discharge and drainage capacity,groundwater drains into the main canal smoothly,ensuring safe operation of the main canal.The major drainage-influencing factors are regional hydrogeologic conditions and dynamic variation of groundwater level.The drainage is closely related to the aquifer where the canal is excavated,and during a year the drainage varies dynamically with phreatic water level.