Groundwater Resources Evaluation And Development Risk Assessment In Shawan District Of Leshan City

Shawan District is located in the north of Leshan City,is Leshan's industrial area.The original Tujiang coal mine,the existing Desheng Group,Southwest stainless steel plant are located in Shawan District,groundwater pollution has become its unavoidable problem.With the rapid development of social economy,the proportion of urbanization population increased,urban construction and heavy industry investment and a series of development,the groundwater resources problems of Shawan District continue to deteriorate.How to strengthen water resources protection,real-time monitoring of groundwater pollution,and to rational development and utilization of groundwater resources to protect the sustainable development and utilization of groundwater has become an urgent task.In this paper,the risk assessment of groundwater development and utilization in Shawan area is taken as the main research content.Based on the current situation of water resources,this paper analyzes the natural geography,geological background,hydrogeological conditions,water resources and water quality evaluation,the results obtained as the basis for the evaluation of groundwater development risk,and taking into account the natural situation,development and utilization of the status,socioeconomic status,the use of mutation evaluation method to assess the risk of groundwater development in Shawan District,The results were improved,and the individual analysis and comprehensive evaluation of the groundwater exploitation and utilization risk in Shawan District of Leshan City were carried out.The main results of this paper are as follows:(1)A detailed description of the physical geography,geological background,hydrogeological conditions of Shawan District of Leshan City,the tropical monsoon humid climate zone in Shawan area,the north and south of the Dadu River basin cross the sandy bay area,and the southwest Northeast,exposing the formation of the whole,in addition to the Devonian,Carboniferous,Silurian missing,from the Upper Proterozoic Sinian to the Quaternary of the loose strata are exposed.Groundwater is divided into three categories according to lithology and occurrence,water quality and hydraulic characteristics: loose rock pore water,bedrock fissure water and carbonate rock fractured karst water.The groundwater chemistry type is mainly HCO3-Ca,HCO3-Ca·Mg.(2)the hydrogeological parameters required for the evaluation data values,and the relevant data are calculated in detail.The total amount of groundwater natural resources is 7840.20×104m3,and the amount of groundwater exploitation is 4449.73×104m3.Water quality,according to the "groundwater quality standards.GB/T14848-93",the main indicators of pollution were analyzed,51 samples taken,17 were heavily polluted,the main indicators of excessive iron,manganese,sulfate,the total solubility Solid and total hardness,of which the most prominent sulfate exceeded.(3)discusses the methods and principles of the groundwater development risk evaluation index system construction in detail,and introduces the principle of the catastrophe theory and the primary abrupt change model.On the basis of this,taking the sandy area of Leshan City as an example,using the catastrophe theory,And the results of the analysis were analyzed.The results of the analysis were analyzed,and three kinds of A-level indexes and 15 C-level indexes were selected,such as the natural condition,the development and utilization status,the socio-economic status,the permeability coefficient,the thickness of the aquifer,the groundwater Depth,precipitation infiltration coefficient,diving evaporation coefficient,annual average precipitation,annual average evaporation,groundwater recharge modulus,groundwater recoverable modulus,groundwater exploitation level,groundwater quality grade,groundwater total water use ratio,population growth Rate,urbanization rate,GDP growth rate.Then the data are normalized,and then the seven basic models are calculated layer by layer,and finally the total target layer evaluation value is obtained.The calculation process does not require any subjective weight,the result is more objective(4)According to the characteristics of terrain and geomorphology of Shawan area and the rich water characteristics of groundwater,13 administrative regions are divided into eight evaluation areas.Overall,the risk value of groundwater development in Shawan area is between 0.1922 and 0.4788,The risk of regional risk is as follows:I-1(0.1922),I-2(0.1934),II-1(0.3291),II-2(0.4034),II-3(0.3823),III-1(0.4788),III-2(0.3777),III-3(0.2309)?III-1?II-2?II-3?III-2?II-1?III-3?I-1?I-2?...