設計耕地建構評估及管理的地理資訊系統

iii ABSTRACT Crop-land management decision-making increasingly requires access to and the analysis of map-based spatial data. Some maps and data layers as land inventory data to accommodate these requirements are available. However, the maps and data layer can be used to compile and distribute spatial data, not to create tools to facilitate the analysis of the data or decision-making based on them. Decision-makers need tools to analyze the spatial data for making a certain crop-land management decision. The objectives of this study are: (1) to use some available spatial map-based data for land unit characteristics determination; (2) to use a semi-detail field land observation for improving the land unit characteristic information; (3) to develop a simple GIS tool for cropland suitability evaluation; and (4) to develop a simple GIS tool for crop-land management decision making. The method of this study would be a geographic information system (GIS) technique, semi-detail field observation procedure, crop-land suitability evaluation procedure, and cropland management decision making procedure. The GIS data analysis and processing in this study were in 3 (three) steps: (1) raw geographic data points analysis and tabulation done in Microsoft Excel and copied into txt file extension in Notepad; (2) interpolating and/or clustering, plotting and 2 dimension imaging processing done in Matlab; and (3) image geographical registration, digitizing and mapping processing done in Mapinfo. It would be a different processing in the first step, if the raw data were not pints data and/or an information data in some case, they would be transferred into quality points data through a scoring process. In the area study, there was found 5 land suitability classes for rice field farming system: (1) permanently not suitable (2,295.60 Ha); (2) currently not suitable (1,325.08 Ha); (3) marginally suitable (10,693.47 Ha); (4) moderately suitable (2,887.30 Ha); and (5) suitable (1,110.01 Ha) and 5 land suitability classes for upland crop farming system: (1) permanently iv not suitable (3,638.24 Ha); (2) currently not suitable (3,114.49 Ha); (3) marginally suitable (9,496.59 Ha); (4) moderately suitable (3,901.38 Ha). The crop-land management decision in the study area: (1) rice field farming system (6,508.08 Ha or 35.54%); (2) a combination of 2 times for rice field in the wet season and 1 time for annual upland crop in the dry season (3,900.46 Ha or 21.3%); (3) fish pond (2,589 Ha or 14.13%); and settlement with mix garden (3919.8 Ha or 21.41%). It is suggested that the GIS data analysis and processing in this study would be better to be applied for geographic data analysis and processing of the flat to undulating land form area because it would be not only high accuracy but also efficient of cost and time consumptions . For a rolling to hilly landform area, it would be better to apply a landform variability approach.