SPATIAL MODELING FOR SOIL EROSION ASSESSMENT IN UPPER LAM PHRA PHLOENG WATERSHED, NAKHON RATCHASIMA, THAILAND (original) (raw)

Phra Phloeng watershed in Nakhon Ratchasima. The study basically aimed to spatially model soil loss to be used for soil conservation purposes. Herewith, two Landsat-5 TM imageries in 2000 and 2008 were classified by using hybrid techniques for land use and land cover classes for vegetation cover and field support practice factors of USLE. Also, other USLE factors which included rainfall-runoff erosivity, slope length and steepness and erodibility were extracted based on mean annual rainfall, DEM, soil and geological data. The land use and land cover in 2000 and 2008 were extracted with their change. Soil loss maps in 2000 and 2008 were produced based on USLE indicated the amount of soil loss in 2000 was more than 2008. Furthermore, severity of soil loss was reclassified into 5 classes: very low, low, moderate, severe and very severe. The result obtained 19.25% moderate, 5.68% severe and 0.02% very severe in year 2000. While the result obtained 17.84% moderate, 5.35% severe and 0.02% very severe in year 2008. Moderate, severe and very severe locations were here emphasized for the soil and water conservation practices. The change of soil loss severity between 2000 and 2008 map was also generated for indicating both increase and decrease in soil loss rate.