Water erosion modeling using the SIMWE (Simulated of Water Erosion)

Abstract

<p>Water erosion analyzes to evaluate the spatio-temporal dynamics of erosive processes can be conducted from different approaches, such as SIMWE (Simulated of Water Erosion), a dynamic model, with a physical base, structured in two modules (surface hydrological flows and sediment flows), designed for a temperate environment, able to simulate erosion, transport and deposition by surface flow, and can be applied in complex situations of terrain, soil and land use. This study aimed to evaluate the dynamics of erosive and depositional processes using SIMWE for the tropical environment in the Alto Espraiado basin - São Pedro (São Paulo State). To evaluate the influence of the parameters selected and used by SIMWE in the generation of erosion/deposition scenarios, three scenarios were simulated with a fixed value of 190 mm/h for the excess precipitation rate and different values ​​for the Manning coefficient, the infiltration, permeability and shear stress. The product of the SIMWE model denominated Balance of Erosion and Deposition indicates that a large part of the area was classified as susceptible to erosive processes (positive values) and for the rest of it as area of ​​depositional processes (negative values). It is noteworthy that the high positive values ​​(erosion) were recorded on the rivers banks (main and tributaries) and sectors that predominate the concave curvature, which from the analysis with the overlay of the map of the erosive features it was also verified that great part of the erosive features polygons are located mainly in concave areas and riverbanks. The rest of the erosive features mapped is distributed mostly throughout the basin area, in sectors of the high, medium and low slope, where SIMWE also classified most of them as susceptible areas (positive values) but with lower values ​​and the other sectors classified as deposition (negative values). Such results demonstrated the feasibility and sensitivity of the application of SIMWE in a tropical environment, being an important tool for the diagnosis and prognosis land use issues, as well to aid for the evaluation and analysis of the distribution and formation of erosive and depositional processes.</p><p><strong>Key Words:</strong> Erosion; Deposition; Run off; Prognosis, Brazil.</p>