MODELING SOIL EROSION POTENTIAL USING USLE AND GIS TOOLS IN THE WATERSHEDS OF COVILHÃ REGION (PORTUGAL)

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-05-8 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 32, 389-396 pp, DOI: DOI: 10.5593/sgem2017/32/S13.051

ABSTRACT

The erosion of the soil is characterized for the disaggregation and transport of the superficial material, promoted by the hydric or eolic action, leading to the impoverishment of the soil, and in extreme cases to the desertification. This process is complex and depends on a multiplicity of factors that differ in the time and space, whose universality and simultaneous particularities, becomes it difficult to equate and to quantify. Modeling can provide a quantitative and consistent approach to estimate soil erosion and sediment yield under a wide range of conditions. In the present study, the soil loss model, Universal Soil Loss Equation (USLE) integrated with Geographic Information System (GIS) has been used to estimate potential soil erosion in the Covilhã region. USLE factors (R, K, LS, C and P) were computed and presented by raster layers in a GIS environment, then multiplied together to predict potential erosion soil rate. It was observed that the potential erosion rate in the study area can be distributed over three levels ranging from 0 to 4 ton.ha-1/year, 4 to 9 ton.ha-1/year and erosion over 9 ton.ha-1/year. These results demonstrate that high terrain, slope steepness, gully and fluvial erosion are the most prominent causes of soil erosion. This study contributes to better management and implementation of soil conservation practices in the Covilhã region.

Keywords: Soil erosion, Modeling, USLE, GIS, Covilhã Region.