Construction Of Soil Information System For Qinling-Bashan Mountainous Area

Since the emergence of Geographic Information System (GIS) technology and its application in the soil research has brought new tool for the development of soil science. Soil Information System (SIS) is a kind of technology system which processed and analyzed the geography data of soil resources properties and the connotation of space, and it has become one of the hot topics in soil science. Under the soil data conservation status of the Qinling-Bashan Mountainous Area, a large number of large scale soil-related data and maps in this region have been collected. Then, Qinling-Bashan Mountainous Soil Database has been established, and as a basis for development of the Qinling-Bashan Mountainous Soil Information System (QBSIS). The QBSIS integrated a number of common GIS analysis and other function models like data management, soil thematic evaluation and so on. It can provide strong data support and basis for conservation and mining use of soil-related data, sustainable agriculture and related agriculture decision analysis in this region. Following with main conclusions:(1) Based on farmland productive evaluation project of Shaanxi province, a large number of soil maps, land use maps, counter maps, soil nutrient maps and other maps in 1:50000 scale and 1:100000 scale have been collected, besides soil samples data, household survey data, soil analysis data, typical section data and so on. All maps have been scanned into raster images and then did some process like coordinate registration, digitization, topology checking, etc. in ArcGIS Desktop 9.3. After preprocessing, the shape vector data should be sort out by the counties. Attribute data should process with internationally accepted units for standardization. Before being inputted into database, the soil-related data also should be classification and encoding.(2) To analyze the situation of the collected soil data, according the principles and methods of database design, it was designed respectively in management, collaborative approach, internal structure and relationship among tables with spatial data and attribute data. Then the detailed design would be make on that basis. The prepared data was input into database to established Qinling-Bashan mountainous area soil database which the personal geodatabase as the spatial data model and the Access software as the attribute database.(3) Have analyzing the integrated requirement of QBSIS, it was determined that QBSIS would be developed by the secondary development way with the Visual Studio 2008 integrated development environment and ArcGIS Engine 9.3 component objects. Thus, the QBSIS was developed which the C# language was the main programming language and the ADO.net technology was used to access the soil database. Its main functions contained were consisted of data management, query and analysis, soil thematic evaluation and mapping and reporting.(4) The level analysis model and membership function model were full implemented in the soil thematic evaluation module. Some counties'farmland productivity and crop suitability were assessed on the basis of existing data; Object-oriented design of the class and optimized algorithms made the system run more efficiently, and to have strong portability and scalability.