Evaluation of vulnerability to loss of soil in watershed of Salobra river, MS, based on the forms of terrain

Abstract

The vulnerability landscape of loss of soil is understood as triggered ruptures by the actions of society in nature, characterizing thus a new organization of phenomena and dynamics in spatial forms that materialize in the landscape. The objective of this article is define the vulnerability of forms of terrain loss of soil, to evaluate the morphological characteristics of vertical and horizontal curvatures of the slopes and forms of terrain. Thus, from the analysis of the slopes established a relationship direct with erosive processes. We used geomorphometric data derived from processing images made in SRTM (Shuttle Radar Topography Mission) Project TOPODATA - INPE, as plan curvature, profile curvature and form of the terrain. Therefore, to define the classes of vulnerability landscape loss of soil, was evaluated that the water flows concentrate and increase the downslope, which was attributed to the lower parts of slopes, or the segments concave, the largest capacity sediment transport. The processing of the data SRTM-TOPODATA, resulting in thematic maps was realized using the Geographic Information System (GIS) SPRING. The results of Forms Terrain though they are qualitative attributes where likely weighing, considering that the dynamics and intensity of erosive processes are directly linked to the terrain forms and slopes of format, so much in analysis of shape format, concave , straight and convex, and in the analysis of the direction of flow of water runoff, convergent and divergent planar. Accordingly, it is considered possible to attribute from the forms of slope and of terrain a coherent a weighting, which can be used as a variable in the analysis of the vulnerability of the landscape to the loss of soil.