Analytical Solution Of Groundwater "Three Nitrogen" Migration And Transformation Model And Its Application

Groundwater is an valuable fresh water resource in our country,which is an important condition for the development of social economy and improvement of people’s life.However,with the rapid development of society,the groundwater environment has been destroyed,leading to the phenomenon of groundwater pollution is more and more common,and there is an increasing trend.There are many factors that cause the groundwater pollution in our country.Among them,"three nitrogen" pollution has been paid attention to as a typical pollution source of groundwater pollution.To prevent "three nitrogen" pollution is an important way to control or change the groundwater "three nitrogen" migration,and one of the solve these problems is make a quantitative study of the law through the mathematical models.At present,most of the groundwater "three nitrogen" migration and transformation studies are carried out by numerical method.Although it can solve complex problems,but time-consuming and expensive,there will be a lot of problems.However,the use of analytical method for groundwater "three nitrogen" migration and transformation research,the applicable conditions are not a wide range of numerical models,but the data requirements are relatively low,the calculation of small workload,easy to use.Now solve the "three nitrogen" migration and transformation of the analytical model is the separation of the three species to solve the single species,so ignore the "three nitrogen" between the interaction.In this paper,the "three nitrogen" is coupled together to obtain its analytical solution based on the problem of coupled multi-species migration and transformation,which provides a further basis for studying the relationship between "three nitrogen".In this paper,based on the research area of Li Guanbao water source area,groundwater "three nitrogen" migration and transformation model is established,and then the analytical solution of the model is obtained,and finally a simple application is made.In the first chapter,the research background and significance and research progress at home and abroad are introduced.In the second chapter,the study area hydrogeological model and preparation knowledge are introduced.In the third chapter,the mathematical model is established on the basis of hydrogeological model,and then the model is solved by Laplace transform and linear transformation.In the fourth chapter,based on the analytical solution,the corresponding program is compiled and the model is calculated,and the analytic solution is used to analyze the parameter sensitivity of the mathematical model.