Applications of geographic information system for agricultural development in Phatthana Nikhom and Chai Badan Districts, Lop Buri Province

Applications of Geographic Information System for agricultural development in Phatthana Nikhom and Chai Badan districts, Lop Buri province were conducted in three sections, namely 1) base-line data collection 2) manipulation and digitization and 3) analysis of soil suitability classes for major economic crops. The base-line data for gricultural development included soil, water topography and crop type. The soil data are provincial soil map and detailed soil maps that were specially prepared to cover the study areas. These soil data were subdivided according the soil-crop requirements. The water data include surface water, rainfall and underground water. The surface water and the underground water have low potential for this development, therefore, only rainwater is available for crop growing. However, the amount and distribution of rainfall in the study areas are very erratic and the available rainfall data were not specific to the area. Hence, a rain gauge was installed to record the amount and distribution of rainwater. There were not sufficient data for statistical analysis at the present. The crop-type data were based on the existing crops in the area. The topographic maps did not provide enough detailed information for landform/topography mapping. Hence, topographical data obtained during the soil survey was employed in the analysis. Socio-economic data were surveyed and used as supplementary information in the GIS analysis. Landsat TM data and aerial photographs were applied for land use mapping. The spatial data were digitized and other information was classified for future analysis. Scoring and weighting techniques were assigned to each parameter in agricultural development. Overlaying of each data set for particularly suitable crops including paddy rice, sugar cane, maize, sorghum, soybean and sun flower were commenced by index and modeling modules of the GIS software. There were three suitability classes, namely suitable, moderately suitable and marginally suitable for specific major crop. Another class that has been masked at the earlier stage as unsuitable was not to be used for agriculture. In includes hills, steep slopes, water body and gravel pits. The derived suitability class for each crop was validated by comparing with the crop yields either by collecting yields from farmer's fields or from experiments. The accuracy is, at present not so satisfactory and needs further investigation.