3D GIS下地下水流有限元数值模拟方法与应用

Finite Element Numerical Simulation Method of Groundwater Flow and Its Application under 3D GIS

目前缺乏针对较强空间特性水文地质计算参数的高效采集方法与管理机制,而且现有孔隙地下水流有限元数值模拟在三维可视化与空间分析等方面仍存在很多不足。因此,本文以有限元数值计算方法和三维地理信息平台为基础,结合GIS空间分析算法和计算机图形学理论,针对孔隙承压地下水有限元分析过程的关键步骤(概念模型构建、空间离散、水文地质参数提取与赋值等),提出了孔隙地下水有限元数值模拟过程在3D GIS下的实现方法和技术框架。基于水文地质钻孔数据和GTP(Generalized Tri-Prism)空间数据模型,以盐城市滨海平原水文地质区为研究区域,实现了地下水系统空间结构特征的三维表达,同时与地下水流有限元数值模型相耦合,提出了3D GIS模型与地下水非稳定流有限元数值模型耦合的核心处理算法,并在此基础上开发了3D GIS地下水流数值模拟系统。应用实例表明,该技术框架可有效简化有限元分析流程、优化模型计算效率、实现地下水有限元数值模拟过程及计算结果的三维可视化。

The existing finite element numerical simulation method of groundwater flow has some defects in the three-dimensional visual spatial analysis and the expression of numerical calculation process and simulation results. In order to solve this issue, the key steps of the finite element analysis process including the conceptual model construction, spatial discretization, hydrogeological parameters extraction and initial condition assignment are taken into consideration respectively. Based on the finite element method and 3D GIS platform, the method and technique framework of the groundwater finite element numerical simulation under 3D GIS are proposed with the supports of GIS spatial analysis algorithms and computer graphics theory. In addition to describe the technique framework, the core algorithms＇ implementation details are given and the complete process of 3D GIS groundwater flow simulation is presented. The groundwater simulation example demonstrates that the proposed method and technique framework are capable of simplifying the finite element analysis process and improving the calculation efficiency of the model. The whole technique framework can be integrated into 3D GIS platform, and furthermore the visualization of simulation process and calculation results can be achieved eventually.