基于GIS的地下水资源分区研究及承载本底评价

Evaluation of natural carrying capacity and zoning of groundwater resources based on GIS

地下水资源承载本底与自然属性密切相关,地下水资源分区是评价地下水资源承载本底的重要基础工作。文章以新一轮地下水资源评价成果和主要平原盆地、部分省(区市)地下水资源最新调查评价成果为基础,综合地形地貌、构造单元、气候分带、地表水流域、含水层介质等多项指标,把地表水和地下水看作一个整体,将全国划分为26个一级区、143个二级区、412个三级区。通过将地下水资源分区与县级行政区划耦合确定了4942个计算单元,利用地下水可开采模数指标,实现了地下水资源承载本底评价由以自然单元的评价到县级行政单元的成果表达,从而建立了地下水资源承载本底评价空间数据基础,可服务于地下水资源承载能力动态评价和地下水合理开发利用与管理。地下水资源承载本底结果显示:我国地下水资源承载本底总体表现出平原盆地区为中-高水平,北方干旱区为低水平,区域差异性较大。承载本底等级为高、较高、中、较低、低的县(区、市)分别为774,332,798,387,573个,面积占比分别为11.15%、5.87%、19.56%、12.09%、52.34%,基本反映出我国地下水资源禀赋条件和区域分布规律。

Natural carrying capacity of groundwater resources is closely related to natural attributes,and groundwater resource zoning is the important and basic work for evaluating the natural carrying capacity of groundwater resources.Based on the results of the recently completed national project of groundwater investigation as well as the latest survey and evaluation results of groundwater resources in the main plain or basins and a number of provinces(autonomous regions),this paper takes the surface water and groundwater as a whole,and divides the mainland areas into 26 first-level zones,143 second-level zones and 412 third-level zones,according to a few indicators such as topography,geological structural unit,climate zoning,surface water basin and aquifer medium.The mainland areas are further divided into 4942 calculation units by combining groundwater resource zoning with county administrative areas.By using the exploitable modulus index,the evaluation results of the natural carrying capacity of groundwater resources are thus assigned to every counties,and a sound basis of spatial data of the natural carrying capacity of groundwater resources evaluation is set up,which can serve for the dynamic evaluation of carrying capacity of groundwater resources and support the rational utilization and management of groundwater.The evaluation results show that the natural carrying capacity of groundwater resources in China is medium-high level in plain basin area,and low-level in the arid areas in north China.There are 774,332,798,387 and 573 counties(districts and cities)with high,mid-high,medium,mid-low and low levels,and the area accounts for 10.15%,5.87%,19.56%,12.09%,and 52.34%,respectively.The results basically reflect the natural conditions and regional distribution of groundwater resources in China.