A Study On Groundwater Vulnerability Assessment In Shapotou District Of Zhongwei City

Shapotou district is a special agricultural products base and a famous desert tourist destination in China.Located in western China,it is also a highland undertaking the industrial transfer from eastern China.However,the Yellow River Irrigation District of the region produces a large amount of farmland receding water all year round.What's more,the discharge of industrial sewage and domestic wastewater increase year by year because of the industrial parks rise and the population increase these years.The groundwater environment in Shapotou district is faced with a huge pollution crisis.Groundwater vulnerability assessment is a kind of crisis assessment of the possible pollution in groundwater system and a basic work to protect groundwater resources.Based on the summary of present research on groundwater vulnerability both at home and abroad,the paper gathers and summarizes the influencial factors of groundwater environment in Shapotou district with spatial analysis ability of GIS.It is the basic data of the paper.The paper conducts the related research as follows:(1)The paper chooses 5 traditional indexes such as:groundwater depth and net replenishment to construct the essential vulnerability assessment model(DRSTC)in Shapotou district.In addition,it also takes human factors into account,adding two indexes(land utilization type,groundwater pollution sources intensity)to construct the special vulnerability assessment model(DRSTCLH),resulting a reliable evaluation achievement.(2)In the process of special vulnerability assessment,the paper combines analytic hierarchy process and entropy method to get the comprehensive weight of special vulnerability evaluation index.The results show that land utilization,groundwater depth,net recharge and groundwater pollution sources intensity are the main factors affecting groundwater vulnerability in the study area.(3)By comparing and analyzing the results of essential vulnerability assessment and special vulnerability assessment,the paper reaches two conclusions.First,some areas with low groundwater vulnerability under their own natural conditions could be changed into high groundwater vulnerability areas under the influence of human activities.Second,the higher the essential vulnerability is of an area,the more vulnerable its groundwater system is from human activities.Based on the results of the two kinds of vulnerability assessment,this paper puts forward some suggestions and measures for the relevant groundwater management departments of Shapotou district in rational exploitation and groundwater resources protection,which has certain scientific guiding significance to ensure the safety of groundwater resources in Shapotou district and promote the sustainable development of regional economy.