Groundwater Simulation-Optimization Study Based On ESRI Add-in Visual Design

Groundwater is a precious natural resource for human beings.However,the contaminated sites caused by human life and production have caused serious pollution to groundwater for a long time,which threaten the survival and development of human beings.Therefore,it is of great significance to treat groundwater pollution.The treatment methods for groundwater pollution at home and abroad can be divided into three categories:ectopic repair technology,in-situ remediation technology,and natural attenuation.The most commonly used PAT technology is one of the ectopic repair technologies.The PAT technology has the advantages of being simple and easy,and quick to respond to groundwater pollution incidents.It is especially suitable for the underground water systems functioning as groundwater source which are expected to reduce pollution levels quickly in the short term.However,its disadvantage is that the repair project is complicated and the operating cost is high.Therefore,effectively reducing the operating cost of the PAT system is of great significance for the promotion and application of the technology.Since the 1980s,the groundwater simulation-optimization model has been applied to determine the optimal strategy for groundwater PAT systems.However,compared with the modular groundwater simulation software widely available at home and abroad,there are relatively few modular simulation and optimization softwares.This situation greatly limits the optimization practice of groundwater simulation-optimization model for groundwater pollution control in actual sites.On the basis of introducing a simulation-optimization software-MGO(Modular Groundwater Optimizer),MGO was used to optimize a PAT system at a contaminated site at an air force base in Utah.The optimization process is divided into three stages to proceed in order to find the most optimal layout of well group,which will result in the lowest cost under satisfying the constraint condition,respectively,under the constraint condition under steady state strategy,the minimum operating cost under the steady state strategy and the minimum operating cost under the dynamic strategy.Stage 1 adds new wells to the original PAT repair system to find feasible solutions to meet the concentration constraints at the boundary units of pollution constraints;Stage 2 finds the optimal well locations and corresponding water injection rates for the newly added injection wells in Stage 1;Finally,stage 3 divides the entire simulation optimization stage into seven management stages,and realizes the dynamic optimization management of the restoration system,respectively searching for the optimal pumping/water injection volume in each management period,so as to achieve the goal of minimizing the cost of the entire project period.As shown by the optimization results,In stage 1,only four injection wells need to be added near the concentration constraint boundary,and only two initial pumping wells and one initial injection well are retained;Stage 2 finds the optimal position of the 4 new injection wells,which reduces the total pumping volume by 1.82%.In the dynamic management strategy of the stage 3,total pumping volume decreased by 5.34%compared to the steady-state strategy of stage 2,resulting in a 10.13%reduction in repair costs and at the same time,the repair efficiency was ensured.The results of the case study show that MGO can effectively improve the economical and efficient management measures for groundwater remediation,provide a reliable tool for the future groundwater remediation,and have a good application prospect.The results of the case study show that MGO can effectively provide an economical and efficient management measure for groundwater remediation and provide a reliable tool for future groundwater remediation.Therefore,MGO has a good application prospect.On the other hand,the data required by the MGO software is input in a text file format,and its result data is stored in a binary format file,ie neither the preprocessing stage nor the postprocessing stage is visualized.So this greatly affects the convenience of MGO in practical applications.For this state that there is a lack of visual research on MGO software,this article uses an object-oriented high-level programming language,C#,to design an ArcMap add-in based on the Add-in of ArcObjects,MGO Add-in.The Add-in not only achieves the visual input of the pre-processing stage,but also uses ArcMap to quickly visualize the result data.The MGO Add-in consists of three parts:(1)MGO visual input interface based on WinForm;(2)interactive conversion of result data format by calling MODFLOW/MT3DMS post-processing program;(3)automatic database creation,generation of point feature set,and loading to ArcMap view.And the MGO Add-in has the following advantages over the text file input method of input data:(1)the visualization of data input and output;(2)the reduction of data input operation amount;(3)the check of input data,The input of data has no order requirement;and(5)the result file is convenient to view.