Avaliação da erosão hídrica actual e potencial do solo no distrito de Changara

Abstract

The determination of areas susceptible to water erosion is fundamental in decision-making involving land use-related activities. These decisions involve preventive measures, aimed at avoiding soil loss and conservation, or reactive measures when current soil degradation is observed, results that allow action on the territory to minimize this phenomenon. In Changara district, this issue has reached alarming proportions, with over 500 families living in high-risk collapse zones due to proximity to gullies, especially in Luenha administrative post. In this context, this work evaluates the spatial distribution of current and potential water erosion in Changara district, Tete Province. The adopted methodology combines remote sensing, GIS, and fieldwork. The SARCCUS method was applied to satellite images for current erosion assessment and the AHP method for potential erosion through the integration of five determining factors (Land Use and Cover, Soil, Slope, Rainfall Intensity, and Drainage Density). The results reveal that 19% of the district's total area is affected by current erosive processes, with a predominance of sheet erosion (9%), rill erosion (6%), fluvial erosion (3%), and gully erosion (1%). The erosion potential assessment showed that 22.3% of the district presents high and very high susceptibility to water erosion. Land use and cover emerge as the most influential factor, acting as a modulator of other factors, especially in shifting agriculture areas and bare soils. The localities of Mazoe, Luenha-sede, and Dzunga emerge as the most affected, both by current erosion and erosive potential