Establishment And Application Of Regional Soil Information System Based On The SOTER And COMGIS

The changes of soil and land resources induced by human being activity, which influence the environment quality and existence space of human being, have been put great attention. With the rapid development of computer technology, integration system of "3S" (GIS, RS, GPS), Soil Information System, Decision Support System and Expert System have been quickly rising. These techniques are the powerful tools to manage the soil and land resources. Anew and international project of 1:100M Soil and Terrain Digital Database (SOTER) have being developed rapidly. First, based on the theory and method of SOTER and combined on the prevalent ComGIS technique and the modem mathematic models, the regional soil information system (HBSOTER) is developed. The HBSOTER incorporates the SOTER attribute database management, spatial database management and professional application models. And the system is applied in suitability assessment of land resources in Hubei province. Then, based on the HBSOTER, the Soil Information System of local scale is established. Furthermore, the soil fertility and natural productivity of cultivated lands are evaluated. In this research, some significative results are obtained and shown as follows:1. Designing and Development of SOTER Database Management SystemFor the first time, a newly SOTER database management system is established based on complete-newly object-oriented software development method and rigorous development process of analyzing, designing, coding and examining. The new one has the following advantages: (1) inheriting and enlarging attribute data management function of original SOTER, and enhancing the integrality and safety of SOTER; (2) integrating the attribute database, spatial database and model storehouse into a uniform system, and using the windows graphic user interface (GUI) as interactive tools which make establishment and maintenance of SOTER database convenient; (3) promoting the digitization, model standardization and automation of soil information.2. Establishment and application of SOTER in Hubei Province (HBSOTER)2.1 After the partition steps of Terrain-Terrain Components-Soil Components, the SOTER units are obtained in terms of main terrains, stone characters and soil types. And the SOTER unit map of 1:100M scale of Hubei Province is mapped. Then the spatial database of HBSOTER is established.2.2 After the information of the national second general soil survey and other results of researches filtrated and transformed, and the SOTER handbook referenced, the necessary attributive data of SOTER is obtained. Using HBSOTER, the attribute data are input into the system, and the attribute database is established. Then it is connected with the spatial database of HBSOTER.2.3 Based on the established HBSOTER and using the SOTER units as the assessment units, the soil resource suitability of Hubei Province about the cropland and the woodland is assessed. In the process of assessment, the Material Element Analysis (MEA) model is used. The results display that the spatial units of 3 levels (terrain, terrain component, soil component) can be stored in SOTER. In the attribute database of SOTER, each SOTER unit includes all the information of different partition levels. And the spatial relations of both in the deferent partition of 3 levels and among them can be indicated. The SOTER can offer the necessary data from the detailed representative soil profile information and the terrain component information for the different level analysis of soil and land resources to apply in deferent scales. Using the MEA as the assessment model eliminates impact of the human preference, so the results are more exact and objective. The results illustrate that the suitable cropland areas in 1, 2 and 3 grades are 2.437Mhm2, 3.495Mhm2 and 1.257Mhm2 respectively. Their percent in the total cropland areas of Hubei Province is 33.9%, 48.6% and 17.5% correspondingly. There are no unsuitable croplands. The suitable woodland areas in 1, 2 and 3 grades are 5.708Mhm2, 2.987Mhm2 and 2.124Mhm2 respecti...