Exploitation Potential Evaluation on Region Shallow Groundwater with Support of GIS

摘要

Taking the Yellow Rive Delta as example, this paper discusses the establishment of potential assessment model for region shallow groundwater development based on GIS technology, and accesses the exploitation potential in the Yellow River Delta. The comprehensive evaluation model considers five factors, i.e. groundwater recharge, aquifer characteristic, groundwater quality, groundwater exploitation intensity and land use. According to the authors set up the basic data respectively. Then using weighted summation assessment model and spacial superposition function of GIS, they built the evaluation results of five influencing factors above (middle layer). Finally obtained a clear map of exploitation potential districts of shallow groundwater in the Yellow Rive Delta with weighted calculation and superposition calculation of space datum. Groundwater recharge considered four factors, i.g. amount of precipitation, buried depth of groundwater level, lithologic character of aeration zone and surface drainage system; aquifer characteristic considered storability of free water and transmissivity; Groundwater quality only considered total salinity; groundwater exploitation intensity was the ratio that exploitable groundwater was divided by practical exploitation of groundwater; land use considered four factors, i.g. farmland, alkaline land, salt lick and other use type of land. Weight of evaluation factors was calculated by Analyzing Hierarchy Process(AHP) and expert evaluation method. First formed a judge matrix, then proved randomicity and consistency of the judge matrix. As a result, the assessment results were divided into five grade districts: most potential, potential, relative potential, short potential and non-potential.