Prediction of potential nitrate point pollution in shallow groundwater in plain area based on GMS in Qinhuangdao

To study potential development trend of nitrate pollution in shallow groundwater in Qinhuangdao plain area, a coupling model of groundwater flow and solute transport was constructed from GMS-based hydrogeology and measured data． The migration and pollution risk of nitrate in groundwater under potential point source pollution in the next 20 years was predicted． Different scenarios of cutting off pollution sources were discussed． The shallow groundwater model was well-fitted to 36 field data and can reflect regional groundwater flow． The main extension direction of nitrate pollution plume in shallow groundwater was found spreading from northwest to southeast coast． The local groundwater flow direction was influenced by exploitation in groundwater source and resulted in significant pollution risk in Houmengying groundwater source in Changli county. In addition, it was found that migration and dilution processes were the main factors to reduce the risk of nitrate pollution in groundwater sources． The timely cutting off of pollution sources could effectively reduce pollution risk． This study will help prevent and control nitrate pollution of groundwater in Qinhuangdao．