Estimativa de erosão hídrica a partir de aerolevantamento remotamente pilotado

Abstract

with annual losses between 20 and 37 billion tons. The process includes a decrease in soil fertility and an increase in erosion, especially in tropical and subtropical areas. Siltation causes economic and environmental damage, and an important factor in controlling soil degradation is its structural stability. The use of Unmanned Aerial Vehicle (UAV) makes it possible to generate cost-effective data with high spatial resolution, as well as allowing it to be used to monitor the environment and assess the risk of soil erosion. The aim of this study was to estimate soil movements that cause erosion and siltation in water reservoirs using information captured by Remotely Piloted Aircraft. The study area was the Barro Branco reservoir, located in Curral de Cima, Paraíba, Brazil. The flight plans were configured with a 70% lateral and 80% longitudinal overlap, a cruising speed of 5 m/s, with two grids, a single one at 50 m from ground level and a double one at a height of 30 m, using ground control points (GCP). Field prospecting revealed the presence of acrisols, plinthosols and arenosols soils around the reservoir, with a predominance of structurally degraded soil and erosion more than 1 meter deep. Estimates of soil loss were made based on the images captured by ARP and the universal soil loss equation (RUSLE), assigning monetary values to erosion losses at two sites, the road and the sugarcane field. The results indicated that a volume of 165.29 m³, approximately 281 tons, eroded, and losses that could exceed a cost of 23 thousand reais. These figures were estimated in just one year. Thus, the importance of using ARP to quantify soil movement causing erosion and siltation, providing valuable information for environmental preservation and proper soil management.