Design And Implementation Of Risk Assessment System For Soil Heavy Metal Pollution Based On ArcGIS Engine

Soil is an indispensable part of ecological environment and the material basis for sustainable development of agriculture and human survival.Soil quality has always been an important issue affecting the ecological safety and sustainable and healthy development of the country.In recent years,with the rapid development of social economy,unreasonable human activities are frequent,which makes the pollution of heavy metals in the soil become increasingly serious in the region.The main reason for the formation of heavy metal pollution in soil is that the microorganisms in the soil can not be decomposed in time,which results in the enrichment of heavy metal elements and converted into more harmful compounds.Some of them are accumulated in human body by food chain,which seriously endangers human health.Lack of understanding of soil conditions will lead to the decline of crop quality and yield,soil degradation and pollution.Therefore,relevant departments urgently need to master the regional soil quality and health status,and adopt appropriate evaluation indicators for regional differences,and formulate appropriate prevention and control measures,aiming at scientific and accurate solution to the problem of heavy metal pollution in soil,The soil quality and productivity level will be further improved.At present,the research on heavy metal pollution assessment in soil is increasing gradually.With the wide application of statistical methods such as correlation analysis,regression analysis and systematic cluster analysis,the evaluation indexes and methods have been developed and improved constantly,but only the improvement in the application of methods and indicators selection has not made great breakthrough in the technical research,There are some limitations.Therefore,considering the huge amount of soil data information and the complex evaluation process,the object-oriented and specific function technology integration can be adopted.Through the development of ArcGIS Engine component,according to the needs of users,the modules that realize various GIS functions can be combined to realize the flexible application and expansion of GIS.Based on the current situation of heavy metal pollution in soil at home and abroad,this paper makes feasibility analysis and demand analysis for the system.On this basis,the algorithm model of the system is selected,including the evaluation model of soil single factor pollution index,the pollution index evaluation model of soil inner Merlot and the evaluation model of soil potential ecological risk index.Based on the algorithm model,the spatial database and attribute database are constructed by using Geodatabase and SQL Server software respectively.Combined with ArcGIS Engine component,the.net is used as the development platform,and C#is the development language.The system design function module is completed by GIS component,and the risk assessment system of heavy metal pollution in soil based on ArcGIS Engine is realized.The system is designed and implemented by five main functional modules,including basic GIS operation functions(roaming,panorama,data creation,saving,saving as,exiting the system,etc.);Query statistics(spatial query,attribute query,adjacency element query,etc.);Spatial interpolation function(IDW,Krige,Spline,Trend,Naturalneighbor and other interpolation methods);The ecological risk assessment function(soil single factor pollution index method,soil inner Merlot pollution index method,soil potential ecological risk index method);The system output function of drawing(map symbolization,map finishing,etc.).Finally,taking the soil heavy metal data of Ningxia Hui Autonomous Region as an example,the system is verified by an example.The spatial distribution trend of heavy metal pollutants is analyzed by interpolation function module,and the map output of the layer is carried out.The system risk evaluation function module is run.The results show that the risk level of heavy metal pollution in the soil in this region is low,But Pb contributes a lot to pollution,accounting for 58.74%.Through this system,it can adjust soil resources efficiently,timely process and update soil resources information,and comprehensively evaluate regional soil resources,so as to provide some theoretical and technical support for the efficient recycling and accurate management of soil resources.The system has high practical value and scientific significance,mainly reflected in the system can provide scientific information and data support for relevant departments and staff,on the one hand,it provides sufficient scientific guidance for regional agricultural structure adjustment and agricultural activities,on the other hand,it provides evaluation basis for verifying the effectiveness of soil project construction and heavy metal pollution prevention and control,The system aims to lay a foundation for the research of soil quality,the development of agricultural science and the rational utilization of soil resources.