利用多孔抽水试验确定承压-无压流条件下承压含水层的水文地质参数  

Hydrogeological Parameter Determination of the Confined Aquifer under Confined-Unconfined Conditions by Means of Multiple-well Pumping Test

作　　者：李丞 王宁涛 胡成[2] 常威 孙伟 黄琨[2] LI Cheng;WANG Ningtao;HU Cheng;CHANG Wei;SUN Wei;HUANG Kun(Graduate School,China University of Geosciences(Wuhan),Wuhan 430074,China;School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430074,China;Wuhan Center of Geological Survey,China GeologicalSurvey(Central South China Innovation Center for Geosciences),Wuhan 430205,China)

机构地区：[1]中国地质大学(武汉)研究生院,湖北武汉430074 [2]中国地质大学(武汉)环境学院,湖北武汉430074 [3]中国地质调查局武汉地质调查中心(中南地质科技创新中心),湖北武汉430205

出　　处：《安全与环境工程》2020年第4期1-7,共7页Safety and Environmental Engineering

基　　金：中国地质调查局地质调查项目(DD20160290、DD20190315)。

摘　　要：在平原第四系孔隙承压含水层开展抽水试验时常发生抽水井中地下水水位降至隔水顶板以下而出现承压-无压流并存的现象,如何利用多孔抽水试验确定承压含水层的水文地质参数是地下水动力学研究中的一个重要问题。利用江汉平原北部肖家港地区第四系上更新统(Qp3^al)孔隙承压含水层中开展的多孔抽水试验,探讨了承压-无压流并存条件下确定承压含水层水文地质参数的方法。结果表明:利用多孔抽水试验数据,综合运用泰斯承压井流模型和Chen承压-无压井流模型可同时确定承压含水层的导水系数、弹性释水系数和重力给水度等关键水文地质参数,据此得到肖家港地区上更新统孔隙承压含水层的导水系数在77.28~109.64 m^2/d之间,弹性释水系数为3.17×10^-4,重力给水度为1.97×10^-1。利用泰斯承压井流模型计算承压含水层的导水系数和弹性释水系数时,应尽量选取抽水后期或者距离抽水井较远的观测井地下水水位降深数据,以尽量减少承压含水层无压区重力释水对计算结果的影响。During the pumping test in the Quaternary pore confined aquifer,concurrent existence of confined and unconfined zones of an aquifer often arises when ground water withdrawal causes the hydraulic head of the pumping well to fall below the top of the confining bed.How to use well flow test in confined-unconfined aquifer to determine the hydrogeological parameters of the aquifer is an important problem in groundwater dynamics.This article presents the details of using the multiple-well pumping test conducted in the upper pleistocene(Qp3^al)pore confined aquifer in Xiaojiagang area in the northern Jianghan Plain to discuss the method of determining hydrogeological parameters of confined-unconfined aquifer.The results indicate that crucial parameters such as the hydraulic conductivity,elastic storativity and the specific yield of the aquifer can be simultaneously determined by the combination of Theis model and Chen model.Based on this,the value of hydraulic conductivity of the upper pleistocene pore confined aquifer in Xiaojiagang area is 77.28~109.64 m^2/d,the elastic storativity is 3.17×10^-4,and the specific yield is 1.97×10^-1.And the conclusions are as follows:when using Theis model to calculate the hydraulic conductivity and elastic storativity,the data of late pumping stage or data of observation wells far away from pumping wells should be selected as far as possible to minimize the influence of gravity water release in the unconfined zones on the calculation results.

关 键 词：承压含水层 水文地质参数 多孔抽水试验 泰斯承压井流模型 承压-无压井流模型 

分 类 号：X141[环境科学与工程—环境科学] P641[天文地球—地质矿产勘探]