Study On The Evaluation And Prediction Of Groundwater Pollution In The Plain Area Of Jilin City

Groundwater is an important water source in Jilin City. The development andutilization degree of the water source is increasing year by year. Therefore, evaluatingthe groundwater quality in the city, identifying the variation characteristics ofpollutants, predicting the concentration of pollutants in groundwater and puttingforward reasonable prevention measures has important significance on the preventionand control of groundwater pollution and improve environmental quality ofgroundwater.In this thesis, on the basis of research topic of Investigation and evaluation ofgroundwater pollution in Jilin city, taking the shallow groundwater in Jilin city as theresearch object, we comprehensively analyzes the data collected in the groundwaterpollution investigation, evaluate the groundwater quality and predict the groundwaterquality.At first, according to the60sets of groundwater quality monitoring data in thegroundwater pollution investigation, the single index evaluation methods and thecomprehensive assessment of groundwater pollution are used to evaluate the qualityof groundwater in the study area. The evaluation results show that the maincontaminants in the groundwater of the study area is NO3--N、NO2--N、NH4+-N、F-、volatile phenol、TDS、Th and the number of the groundwater monitoring wells whosewater quality exceed grade III is65%of The total sum. On the basis of groundwaterenvironment background value of the study area, we use pollution index meThod toevaluate The groundwater pollution situation, the evaluation results show that thetypes of groundwater in study area is mainly secondary pollution and severe pollutionand the influencing factors is mainly NO3--N、NO2--N、NH4+-N and permanganateindices.According to the contamination rate of size, we measure the maincharacteristics of pollutants in the study area and determine. The characteristics ofpollutant is NO3--N. By using the Daniel trend test method. We do the concentrationchange trend analysis over the years（1984~2014） and analyze the sources of pollution combined with the pollution source distribution.Besides, according to the groundwater quality assessment results in the studyarea, we determin the typical pollutants in the groundwater is nitrate nitrogen andanalyze the dynamic variation of the annual (1984~2014years), we find the mainsource is agricultural pollution and life pollution. To this end, we establish thecontaminant transport model of shallow groundwater in the plain area of Jilin plain,and we use the GMS software to solve the problem. According to the observation wellquality of groundwater observation data and calculation results in the research area,we select the time series (2004~2014years) for the identification of the modelverification period and repeatedly debug parameters to improve the accuracy of themodel. We make a comparison of the measured data and simulation data, the results ofsimulation have good agreement with the observed one. Based on the situation offertilization condition, we predict migration and variation trend of underground water"nitrate" in the next ten years. The results showed that the majority of quality in thestudy area of suburban was polluted to a certain extent. Near pollution sources, theconcentration of pollutants is high, the change trends of water quality of groundwateris slow deterioration and more than the forth and fifth class groundwater area ratioincreases, the third class groundwater area ratio decrease Therefore, we shouldincrease the groundwater pollution control efforts to control groundwater pollution.At last, according to the evaluation results and prediction results, we put for wardsome control measures from economic measures, technical measures, engineeringmeasures and management measures in order to protect the water resources securityand this provide decision-making basis for the protection of groundwater resourcessecurity.