基于地面沉降控制的区域性松散沉积层地下水可采资源规划评价

为了满足区域性松散沉积层地区地面沉降的防控要求，规划评价地下水的可采资源量，根据渗流理论和土力学理论，建立了地下水三维非稳定渗流与地面沉降耦合数学模型，并考虑了含水层孔隙度、渗透系数、储水率随含水层发生固结沉降的变化特征。采用三维有限元数值分析方法，以江苏省南通市地下水开采为例，基于地面沉降的控制要求，规划评价出了各乡镇各含水层的地下水可采资源量。结果表明：地下水开采布局科学规划后，总的可采资源量为17 870.56×10⁴ m³/a，较现状开采量10 902.32×10⁴ m³/a有较大幅度的增加。地下水三维变参数非稳定流与地面沉降耦合模型可以更加精确地刻画三维水文地质体的特征，更加符合实际情况。

Plan and Evaluation of Groundwater Exploitable Resources on the Basis of Land Subsidence Control in the Regional Loose Sediment Area

In order to combine the plan and evaluation of the groundwater exploitable resources with the requirement of the protection of land subsidence in regional loose sediment area,based on the theory of seepage and soil mechanics,a coupling mathematical model between the three-dimensional non-steady groundwater seepage flow and land subsidence which considers the change characteristic of porosity,permeability coefficient and water storage rate of aquifers with consolidation subsidence of aquifer was established.A three-dimensional finite element analysis method was applied to the mining of groundwater in Nantong of Jiangsu Province,based on the control requirements of land subsidence,the groundwater exploitable resources of each aquifer in all the villages was evaluated.It is shown that the total groundwater exploitable resources is 17 870.56×104 m3/a on the basis of the scientific plan of the groundwater exploitation allocation,compared with 10 902.32×104 m3/a of the groundwater exploitation quantity in the present state,the groundwater exploitable resources on the basis of the scientific plan of the groundwater exploitation allocation is increased greatly.The feature of the three-dimensional hydrogeology system is able to be described more accurately by the coupling model between the three-dimensional variable parameters non-steady groundwater and land subsidence,which is more suitable for the practical situation.