A study of the influence of land subsidence on hydraulic parameters and water supply capacity
-
摘要: 地面沉降主要由深层地下水开采造成，含水层的压缩释水是深层地下水开采量主要构成来源，同时随其压缩变形孔隙比减小造成储水系数、渗透系数的减小，对弱透水层非弹性释水量、越流补给量造成影响。地面沉降过程中的水文地质参数非线性变化及对承压含水层系统的反馈作用也成为水文地质领域的前沿问题。为对地下水开采量、沉降量、地质参数变化以及给水能力变化之间的关系做一个较为定量定性的探究，以含水层压缩过程中的物理机制为依据，并基于沧州地区深层承压含水层的地下水位变化过程和水文地质参数，采用数学手段构建储水系数和渗透系数变化的一维非线性沉降模型。模拟结果显示随承压水头下降，储水系数最高可减小77%，含水层系统的给水能力和储水能力会随压缩变形减小50%甚至更多。研究成果为深入认识水文地质参数与应力变化相关关系、科学评价承压含水层地下水储水调节能力有重要借鉴意义。Abstract: Land subsidence is mainly caused by the exploitation of groundwater in deep-seated aquifers, which is mainly composed of the compressed water release from the aquitards. At the same time, the reduction in void ratio caused by the compression of the aquitards will further reduce the storage coefficient and the coefficient of permeability, which will affect the amount of non-elastic water release and leakage recharge of the aquitard. The nonlinear variation in hydrogeological parameters and the feedback effect on the confined aquifer systems during land subsidence have also become frontier issues in hydrogeology. In order to make a quantitative and qualitative exploration of the relationship between the amount of groundwater extraction, amount of sedimentation, changes in geological parameters and changes in water supply capacity, this paper constructs a 1-D nonlinear settlement model of the change in storage coefficient and coefficient of permeability based on the change in groundwater levels and hydrogeological parameters of the deep confined aquifer in the Changzhou area. The simulation results show that the storage coefficient can be reduced by up to 77% with the decrease in hydraulic head of the confined aquifer, and the water supply capacity and water storage capacity of the aquifer system will decrease by 50% or more with the compression deformation. The research results are of important reference significance for understanding the relationship between hydrogeological parameters and stress changes and scientifically evaluating the groundwater storage capacity of confined aquifers.
-
Key words:
- deep groundwater /
- land subsidence /
- storage coefficient /
- nonlinear model /
- water supply capacity
-
-
计量
- 文章访问数: 1671
- PDF下载数: 10
- 施引文献: 0
下载: