The Evaluation Of Groundwater Quality And Health Risk Under The Influence Of Agricultural Activities In Songyuan Irrigation Area

An important part of water resource is goundwater,whose quality and environment health have a significant influence on the local human life,social economy and ecological environment.Songyuan Irrigation Area is a key project of Jilin province to increase the production capacity of a million tons of commercial grain,located in the western plains of Jilin province.The construction of irrigation area effectively guarantees water quantity for the agricultural production of the research area.But with the heavy use of chemical fertilizers to improve the agricultural output,large quantities of agricultural non-point source pollutions pollute the regional water environment.On the issues of the possible effects and risks of the agricultural non-point source pollutions to the quality and health of water in Songyuan immigration area,combined with Johnes output coefficient model and water chemical analysis software,the paper assesses the quality of the groundwater and the possible health risks of agricultural activities in the research area and provides scientific basis for water resource development and the management of agricultural production in irrigation areas.This paper mainly carries out the following research:(1)According to the statistical yearbook and pollution census database from Jilin province,first,the paper systematically analyses the pollution of the planting,livestock breeding and the rural life.Second,it establishes a Johnes output coefficient model for agricultural non-point source pollution load.Third,it calculates the pollution load to quantify the possible entry of pollutants into the water.The conclusion is that the agricultural nitrogen and phosphorus pollutants produced by the research area and brought into the groundwater by means of runoff have a great effect on the water environment.(2)Based on the 60 groundwater sample points and surface water chemical test data in irrigation area,on the one hand,the paper uses SPSS software to calculate the water chemistry parameters and analyses the chemical characteristics of groundwater water and its forming function.On the other hand,it utilizes Aquachem software to study the changes in the chemical causes of water.(3)Based on the analysis of the agricultural background pollution and hydrochemical characteristics in the irrigation area,the paper uses the single index evaluation method and fuzzy mathematical evaluation method to evaluate the present situation of groundwater quality in study area.The study area is composed of neogene confined water,quaternary confined water and quaternary unconfined water.From deep to shallow,the results show that the class IV and class V water which exceed the drinking standard gradually increase,the polluted water expands and the groundwater quality gradually becomes worse.(4)According to the test data and the evaluation results,the nitric nitrogen in groundwater is selected as the main pollutant.Using the non-carcinogenic evaluation risk model provided by the environmental protection agency(EPA),the paper evaluates the health risk of nitrate in groundwater from the research area.The results show that the extent of the health risk index(THI)is 0.00-24.01,while the exceeding standard rate is 41.67%.Based on the results of the health risk assessment of nitrate from ArcGIS software,the risk area is 59.18%.