关键词: 笛卡尔切割单元法, 环境影响评价, 地理信息系统, 可视化, 地面水环境

Abstract:

The numerical simulation of pollution dispersion within complex river course and its visualization on Geographic Information System (GIS) are very important to surface water Environmental Impact Assessment (EIA). But there still remain many difficulties and problems, such as grid generation, numerical simulation model of pollution dispersion and the visualization of result. To resolve these problems of area river pollution calculation and GIS-based visualization for point source side discharge situation, the ways of surface water EIA visualization based on Cartesian cut cell method were presented. The Cartesian cut cell method was applied to generate grid, by using cut cell intersection point chasing algorithm and choosing approach of background Cartesian grid in river course boundary, the Cartesian grids of complex river course were achieved. A self-adaptive grids refinement algorithm with steady state pollution decay model was proposed. Based on unstructured Cartesian grids, a point source river water pollution simulation model of side discharge was provided and an area filling algorithm was developed to achieve the visualization of EIA result. Through the visualization and analysis of a river pollution EIA example, the practicability and efficiency of the proposed methods were confirmed.

Key words: Cartesian cut cell method, Environmental Impact Assessment (EIA), Geographic Information System (GIS), visualization, surface water environment