Evaluation Of Groundwater Function In The Northwest Plain Of Ili River Valley

The evaluation of groundwater function is an extension and supplement of groundwater resources evaluation,which is based on the emphasis on resources in the past and the neglect of groundwater ecology and geological environment function.Through functional evaluation,the status quo of regional groundwater function is identified to guide the development and utilization of groundwater,so as to realize the sustainable development and utilization of groundwater resources,which is the threshold of groundwater development under the condition of maintaining ecological environment and protecting geological environment.This study takes the theory and method of groundwater system as the guide,takes the Quaternary groundwater system in the northwestern plain of the Ili River valley as the research object,takes the sustainable system of the comprehensive function of groundwater as the overall goal of the system,and uses the theory and method of groundwater function evaluation.Systematic analysis of the characteristics of the Quaternary groundwater system,combined with the status of development and utilization of groundwater resources in the study area,selected indicators that characterize the functional status of resources,ecology,and geological environment of the groundwater system in the study area,and constructed three functional layers by hierarchical structure.Indicators,9 attribute layer indicators and 18 basic layer indicators constitute a groundwater function evaluation system.Through comprehensive analysis of hydrogeological conditions,based on the analysis of groundwater recharge,runoff and excretion characteristics of the main two-level units,and the division of the small watershed in the region and the position of surface water body,geological structure,and the transformation of groundwater and river,the research area is divided into 28 basic evaluation units.The weights of each index in the evaluation system are determined by analytic hierarchy process.Based on the calculation of the base value of the index,the MAPGIS software is used to analyze the base grid of the evaluation area,and the index base value is given to the center point of the split grid,then the groundwater function result is calculated by GFS software,and the calculation results are partitioned into graphs.The evaluation results showed that:As far as resource function evaluation is concerned,from north to south,there is a relatively strong-relatively weak-relatively strong change trend,mainly in the general functional area of resources,with an area accounting for 62.92%;followed by a weaker resource function area,stronger and more Strongly-typed areas are distributed in front of the northern mountains and can be mined.In terms of ecological functions,the main areas are weak and weak,followed by general areas of ecological function,and strong types of ecological functions are mainly distributed in the central and northern deserts and along the Ili River.In terms of geological functions,the main areas are mainly poorer types,accounting for about 82.03% of the area,followed by general types of areas.The stronger areas are scattered only near the Yaomo Mountain and the LiangFanchang.There are no geological features and poor type areas.The results of comprehensive function evaluation indicate that the overall sustainability of the research area is general,the area of stronger and weaker areas is similar,and the weak sustainable areas are only distributed in the middle of the desert area.Based on the general regularity of groundwater function of inland basins and exploitation potential of the research area,the evaluation results of groundwater function are validated and the reliability of the evaluation results is proved.