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SPATIAL MODELING FOR SOIL EROSION ASSESSMENT IN THE PALOUSE REGION, WASHINGTON, IDAHOSoil degradation has been a major problem that regions around the globe face including several areas of the United States of America. Extensive researches were conducted to address the issue of soil erosion around the world and across the United States; however few focused on the visualization and quantification of the phenomenon despite available tools and methodologies. The purpose of this study is to estimate and map, on a yearly basis, the amount of soil loss, in the Palouse region, located between Washington and Idaho States. In fact, the area comes first over the whole country in terms of soil deterioration. In order to attain those objectives, the Universal Soil Loss Equation (USLE) (Wischmeier & Smith, 1978) was used into the ArcGIS environment. Digital Elevation Model (DEM) combined with factor maps such as rainfall and land use land cover as well as tabular data from published sources served as input to build the soil loss model. As a result, a map (see Map 10) showing the spatial distribution of soil loss was produced highlighting the Southeastern of Whitman, Eastern Spokane and Northern Latah Counties as the most hit. Also, five different classes of loss were set: 0-10, 11-20, 21-50 and 51-500 tons per hectare and per year. Despite the fact that most of the losses are comprised from 0 through 10 tons, significant amount are recorded between the 51-500 intervals particularly in the locations mentioned above. The findings are not contradictory to the 46 tons average that is given in literature. They suggest, however, that any generalization of one value for the entire region is to be avoided despite the relatively uniform distribution of the issue. Fichier: 
Rubrique: Mémoire/Travaux Auteur: Guetchine Gaspard | Date: 17 Dec 2012 |
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