Impactos da vegetação na cobertura do solo e na perda de solo por erosão superficial na bacia do rio Guandu - ES

Abstract

Land use is one of the most important variables impacting river basin water and soil erosion. This study investigates the impacts of landcover changes on sediment transport in the Guandu river basin, Brazil after the implementation of a National Native Vegetation Restoration Policy. For this purpose, it was performed a multidisciplinary approach that combines sediment records and empirical model to estimate the potential soil loss for the years 2012 and 2021. The effect of land use/land cover modifications on sediment yield was studied using suspended sediment records and satellite images data. The pattern of two sediment periods samples from the main channel changed, which indicates that the NNVRP experienced progress after the land reclamation activity. Sediment yield observed from the monitoring gauges ranged from 0.26 t⋅ha-1⋅year-1 to 1.68 t⋅ha-1⋅year-1 in 2012, and 0.40 t⋅ha-1 ⋅year-1 to 0.76 t⋅ ha-1⋅year-1 for the year 2021. In terms of sediment delivery ratio, even with the lower mean annual rainfall depths and erosivity, the year 2012 presented the mean annual value of 8.5%, while 2021 showed a mean annual value of 6.2%. Those results have provided important information for measures associated with the management, conservation and planning of land use in the basin, which is highly relevant for predicting development of various scenarios for the GRB and the application of conservation policy in other basins.