地下水流场的3维数值模拟及可视化研究——以常州-武进地区为例

通过研究常州一武进地区地下水流场的3维数值模拟，揭示了该地区产生地面沉降的主要成因。首先分析了该地区的水文地质条件，在此基础上建立了第Ⅱ承压含水层地下水流场的3维数值模型，采用3维有限差分法对其进行数值求解，并利用体视化中的混合体绘制算法，结合计算机动画技术实现了地下水流场的3维动态可视化。经过研究发现：该地区第Ⅱ承压含水层是最主要开采层，其长期超采是产生地下水降落漏斗与地面沉降的主要原因；地下水降落漏斗中心主要分布在沪宁铁路沿线工农业发达的人口密集区，地面沉降范围与地下水降落漏斗范围基本吻合，且沉降量和沉降速率与地下水位下降幅度和下降速度趋势一致；但是当地下水位出现大幅回升时，地面回弹现象并不明显，这表明地面沉降基本上是不可逆的。因此，该地区必须严格控制第Ⅱ承压含水层的地下水开采量，以免造成环境地质灾害的进一步恶化。

The Research on 3D Numerical Simulation of the Groundwater Flow Field and Its Visualization--Take the Changzhou-Wujin District as an Example

This paper aims at the study of 3D numerical simulation of the groundwater flow field of the Changzhou-Wujin district, for revealing the main cause of the depression of the ground surface. First, the hydro-geological conditions of this area are analyzed. Based on this, a 3D numerical model of the groundwater flow field of the second confined aquifer is established. Then the numerical solution of this model is found using the 3D finite difference method. And finally, the 3D dynamic visualization of the groundwater flow field is realized using the hybrid rendering algorithm of the volume rendering combined with the techniques of computer animation. Through this study, it has been found that the main mined layer is the second confined aquifer of this district and its long term over exploitation is the main reason for giving birth to the cones of depression of the groundwater and the depression of the ground surface; the centers of the cones of depression of the groundwater are mainly distributed along the Shanghai-Nanjing railway where the industry and agriculture are flourishing and is heavily populated; the range of the depression of the ground surface and that of the cones of depression of the groundwater are basically identical, and the depression intensity and the depression rate of the ground surface are much related to the falling extent and the falling rate of the groundwater level. However, the phenomenon of the rebound of the ground surface is not prominent, when the groundwater level rises to great extent, that means the process of the depression of the ground surface is basically irreversible. Therefore, it is absolutely necessary to strictly control the mining amount of the groundwater of the second confined aquifer of this district, so as to avoid the further deterioration of the environmental geological catastrophes.