SOLE RELIEF RELATIONSHIP FOR UNDERSTANDING THE EROSIVE PROCESSES OF THE RIO DOCE / RN HYDROGRAPHIC BOWL
Hydrographic basin; Sweet River; erosion; Toposequence.
The catchment area of the Rio Doce is one of the most important basins for the supply of a significant portion of the population of the Metropolitan Region of Natal. In recent years, the Rio Doce basin has been affected by the urbanization process, through strong real estate growth in the Natal North Zone and mainly in the municipality of Extremoz and São Gonçalo do Amarante. The expansion of the Extremoz industrial district leads to inadequate land use, which further contributes to the development of erosion processes in certain areas within the basin. Already in the rural areas of the basin, the significant presence of small and medium farms leaves the terrain exposed to rainfall erosivity conditions. These interventions contribute to the acceleration of the erosive processes that end up influencing the pedological system that, consequently, will also affect the water conditions of the Rio Doce basin. This research aims to characterize the three - dimensional organization of the pedological cover present in the catchment area of the river Doce, as well as its relation with the erosive processes of the region. As a major factor for the analysis of erosive processes, this study addresses the relationship between relief and soil, starting from the idea that relief influences soil development and this in the evolution of relief. In order to carry out this research, we used the theoretical and methodological assumptions of Ab'Sáber (1969) and Ross (1990) for the compartmentalization of the basin in natural units and Ruellan & Queiroz Neto (1985) and Boulet (1993) . Three natural units were mapped in which positions were identified to identify the main soil characteristics of each unit. It was verified that the soils in the three units present great susceptibility to erosion, especially in the slopes near the beds of the Mudo, Guajiru and Doce rivers.