A SYSTEM FOR SUPPORTING SOIL MAPPING ON THESLOPING LANDS OF NORTHERN THAILAND

摘要

In this paper, a system for supporting soil survey on the sloping lands of northernThailand is described. Geographic information system (GIS) is used for landform classificationand delineation from terrain attributes in preparation for field inventory and mapping of thesoils. The automated delineation of soil-landscape elements is accomplished by a user interfaceoperated in ArcGIS environment. Spatial databases and necessary parameters for theunsupervised classification may be altered to fit the scale of soil mapping and the nature ofterrain being mapped. The resulting soil-landscape units are transferred into a personal digitalassistant (PDA) connected with a global positioning system (GPS) and equipped with a userinterface for assisting the sampling plan for field inventory of the soils. The system alsofacilitates the entry of soil descriptions at the sample sites and stored as a soil polygon attributetable. The field data are transferred back to GIS in a desktop environment to edit the soilpolygons and correlate them with taxonomic classification as required in soil mapping process.A typical landscape on the highland of northern Thailand was selected as the study area. Theresults of unsupervised classification soil-landscape elements were compared with thosedelineated by aerial photo interpretation of the same area.