Modelagem e caracterização da dinâmica morfossedimentar da bacia hidrográfica do Rio Jundiaí- RN

Abstract

The Jundiaí River Basin (BHRJ), located in the state of Rio Grande do Norte, is a planning unit for water resource management, which is exposed to intensified erosion phenomena, which cause siltation of water bodies, among other problems. Although the area is relevant, there is a lack of detailed studies on its characterization and hydrosedimentological dynamics. In view of this, the study aimed to apply the Unit Stream Power Based Erosion Deposition (USPED) model to estimate soil erosion and deposition, integrating anthropogenic, biotic and abiotic factors, evaluate the sediment balance in the BHRJ, present environmental variables of the area, quantify water erosion and relate it to land use classes and identify erosion and sediment deposition zones. The research analyzed factors such as rainfall erosivity, soil erodibility, land use and management, topographic factors, sediment flow estimates and erosion and deposition, generating maps relating to environmental characteristics with the aid of a geographic information system (GIS). The results showed a net erosion/deposition rate of 10,876.65 tons/ha/year and an annual rate of 978.89 tons of soil per year. As for erosion activity, there was an estimated loss of 2,799,711.49 tons/ha/year and a loss of 251,974.03 tons per year, or 6,300 dump trucks with a total load of 40 tons. The areas of erosion are associated with regions of more undulating terrain and where there is extensive anthropogenic use of the soil, as well as high rainfall rates and more erodible soils, and the zones of deposition with areas of low rainfall and more conserved soil cover. The results indicated that the main areas of the basin with a visible and prominent influence of the factors analyzed are the source and the mouth, indicating that territorial planning and water management policies should be focused mainly on these zones.