VI-3 Mapping of soil salinity and soil erosion in Thailand with emphasis on computer-assisted techniques

Abstract

The environmental problems of soil salinity and erosion represent two major challenges to agriculture in Thailand. Both problems require careful assessment of their in situ status and spatial variation in order to implement appropriate control measures. Here, we review the current state of relevant research on the mapping of these two problems, placing an emphasis on computer-assisted techniques. Salt-affected soils are mapped based on the percentage of salt crusts formed in the area. The techniques used are related to simple digital classification of multispectral remotely sensed data. In soil erosion mapping, the erosion risk caused by water is determined, and most such maps in Thailand are based on values that are derived from various factors through the universal soil loss equation. However, the methods used to determine the levels of each of the factors vary according to different producers. Although computer-assisted mapping of soil salinity and soil erosion has yielded useful results, further improvement is needed. In addition, promising new techniques must be fully tested prior to their adoption in Thailand.