Research On Early Warning Of Karst Groundwater Pollution Based On GIS

The karst aquifer groundwater is one of the most important resources for the world's population drinking water supply.China's karst groundwater resources are very rich,accounting for about 1/4 of the country's groundwater resources.There are many springs in Jinan,which is typical of the karst springs in northern China.It has high ornamental value and scientific research value.Due to pollution problems,Jinan Springs can no longer be used as a source of drinking water,which directly reduces the amount of groundwater available for development and use.The deterioration of the quality of spring water also affects the coordinated development of the city.The pollution of karst groundwater in Jinan is due to the discharge of pollutants from human activities on the one hand;on the other hand,due to the thin or absent surface soil in karst areas,the protection capacity is insufficient.Groundwater pollution risk assessment and early warning and assessment of groundwater pollution are important means for the protection of regional groundwater resources.Prior to the further deterioration of groundwater,effective and timely warnings should be given to help decision makers and managers to formulate management strategies and guidelines for groundwater protection so as to achieve the sustainable use of groundwater resources.This dissertation investigates the risk assessment of karst aquifer pollution in the karst groundwater pollution warning system.It contains three levels of content: one is the risk of pollution source loads;the second is the inherent vulnerability of aquifers;and the third is the harm of pollution.Pollution source load assessment is the evaluation and quantification of pollution sources;groundwater vulnerability assessment is an assessment of pollution pathways and groundwater susceptibility is considered;pollution hazards are mainly the evaluation of targets and consideration of the consequences of pollution.Based on the hydrogeological investigation of Jinan karst aquifer in the study area,this paper sets up a groundwater pollution warning system suitable for karst aquifers in Jinan from the local actual conditions,and evaluates the karst groundwater pollution risk and groundwater pollution warning in the Jinan spring area.Compared with previous work,the characteristics of this paper's research are as follows:(1)According to the hydrogeological conditions of the karst aquifer in Jinan,the COP method suitable for the intrinsic vulnerability assessment of the northern karst is selected;the pollution source load risk is analyzed from the sources of pollution sources,the amount of pollutants generated,and the probability of release of pollutants,and a comprehensive index of downstream migration is proposed.F to determine the point source pollution affected area,including the size and direction,the application of GIS overlay analysis to take into account all the sources of pollution in the study area of the risk distribution.(2)Based on the traditional risk assessment methods for grading and re-stacking,a method for calculating the risk intensity factor of groundwater pollution that can determine the priority level is proposed,and then the grading evaluation is performed,which is conducive to obtaining the priority of the control of groundwater pollution risk sources and avoiding the Subjectively human-induced impacts on groundwater pollution risk.Using the obtained groundwater pollution risk intensity factor and pollution hazard,the groundwater pollution risk assessment is more in line with the actual situation,which is convenient for practical application.Utilize groundwater pollution risk assessment results,comprehensively consider the groundwater quality status,groundwater quality trends,and provide comprehensive early warning of groundwater pollution.The results showed that:groundwater pollution without police,police,police,heavy police and giant police area accounted for 22.38%,24.54%,28.42%,11.33% and 13.32% of the demonstration area.For areas with different groundwater pollution warning levels,targeted pollution risk management and control technologies have been put forward,and the results have a certain guiding significance for the scientific management and risk control of groundwater quality in the study area.