Study On Prediction Model Of Groundwater Trinitrogen Pollution In Hohhot

Groundwater is one of the main water sources in Hohhot city.Due to the increasing demand and exploitation of groundwater and the large use of nitrogen fertilizer,a series of geological environment problems such as underground funnel and groundwater pollution have appeared in some areas of Hohhot city.Among them,the groundwater is particularly seriously polluted by "tri-nitrogen",which has become the research object of many scholars and attracted extensive attention from the society.In this paper,groundwater diving in Hohhot City,Inner Mongolia Autonomous Region was taken as the research object,and "tri-nitrogen" in groundwater was taken as the index.Arc GIS was used to conduct interpolation analysis on the monitoring data of "tri-nitrogen" concentration,and the pollution status of "tri-nitrogen" was analyzed.According to the hydrogeological survey data of Hohhot city,through the analysis of the quaternary geological characteristics and hydrogeological characteristics in the study area,the hydrogeological conceptual model is established,and the study area is generalized into heterogeneous isotropic three-dimensional unsteady flow.By using Visual Modflow software,the groundwater flow model is established,and the model is divided and disintegrated,and its reliability is identified and verified.It shows that the structure of aquifer,the generalization of boundary conditions and the selection of hydrogeological parameters are reasonable,and the model can truly reflect the local hydrogeological conditions.Based on the groundwater flow model,a multi-component solute transport model was established to quantitatively describe and predict the pollution status of "tri-nitrogen" in groundwater.Comparing the predicted results of pollutant migration with the measured data,the established mathematical model can simulate the current situation of groundwater phreatic flow and solute migration in the study area more scientifically and reasonably,and predict the future trend of groundwater change more accurately.The predicted results show that the pollution of "tri-nitrogen" decreases with time.Diving nitrate,nitrite exceeded the standard point more,mainly located in the suburbs and rural areas.