Study On Design And Development Of WebGIS System For Soil Erosion Model

China is one of the countries with the most serious soil erosion in the world,and the impact of soil erosion on the sustainable development of our society and economy can not be ignored.In order to analyze the factors affecting soil erosion and its mechanism,many scholars at home and abroad have studied the relationship between erosion and sedimentation and the influence factors,and established several soil erosion models on the basis of prototype observation since the twentieth century.Time to the twenty-first century,"3S" technology,computer science and network technology began to be applied gradually to soil erosion research process,soil erosion involves a large number of spatial data and the cooperation of the relevant departments,requiring spatial data can be updated in the shortest possible time and timely monitoring and forecasting,which makes the traditional stand-alone model of soil erosion system unable to meet the needs of multi-sectoral collaboration and efficient operation.With the continuous improvement and development of Web technology,Web Service has become the W3 C recommendation method to realize the inter site resource invocation.Web Service does not consider the difference between the platform,nor the programming language,while the Web Service provider does not need to consider calling the client,different users through their respective clients can be applied.In the field of soil erosion,although a variety of stand-alone application systems have been established in many research cases,the application of soil erosion model based on Web Service has many advantages.The model based on Web on the one hand does not need to be installed on the client,so the model updating can be realized only by modifying the server model,the model based on Web is based on a unified browser interface,easy to operate,to facilitate the application of soil erosion model,which is of theoretical and practical value in the field of soil erosion prediction.In this paper,the annual experience forecast model of soil erosion is taken as an example.The system uses Web Service technology,combined with ArcGIS API for Flex to build front end application,and based on ArcGIS Server to develop soil erosion year experience model web service.The system realizes the network sharing and online calculation of soil erosion model,and supports the application of it.The main results are as follows:(1)This paper systematically analyzes the data demand and functional requirements of the Web GIS model of soil erosion experience model,and sorts out the calculation of each factor of the model and the calculation process of soil erosion.On this basis,the system design is carried out,including the definition of the system spatial database structure,the design of the overall system function module and the system logic structure,and the system environment configuration.(2)The system designs the factor computing Web service of the annual empirical model of soil erosion,based on ArcGIS Server,analyzes the service release based on geoprocessing model and method based on Python script,and discusses the key technologies such as service interface,service parameter and service response.(3)Using the ArcGIS API for Flex,the annual experience model of soil erosion is constructed,which realizes the application of basic data browsing,model factor calculation,soil erosion model calculation and result query and visualization.Based on the analysis of the mainstream Web Service and WebGIS technology,this paper defines the soil erosion model service interface which conforms to the network service standard,provides different application calls,and realizes the online sharing and calculation of the soil erosion model based on the ArcGIS Server platform,which the model updating can be realized only by modifying the server model.The annual experience model of soil erosion is constructed based on ArcGIS API for Flex technology,which realizes the application of basic data browsing,model factor calculation,soil erosion model calculation and result query and visualization.The soil erosion empirical model WeGIS system provides a complete solution for soil erosion model prediction and forecasting in big data era,which provides the basic support for soil erosion application.