Estimativa do volume sedimentar em uma confluência fluvial do rio Araguaia utilizando plataformas aéreas não tripuladas

Abstract

Aerial surveys of the Earth's surface conducted using Remotely Piloted Aircraft Systems (RPAS, or drones) have been widely employed in volumetric calculations across various applications, including geology/mining activities, agriculture, and forest management (timber extraction and reforestation). In this study, photogrammetric techniques and three-dimensional landscape modeling were employed, combined with the use of an RPAS, to quantify the volume of sediments deposited and/or stored at the confluence of the Araguaia and Vermelho rivers, located in the municipality of Aruanã, state of Goiás, Brazil. The sediment dynamics in this region are configuredas a direct response to land use and land cover changes in the Araguaia River basin, particularly intensified since the 1960s, as well as to the influence of morphosedimentary units of the alluvial plain. The methodology was based on the processing of a set of aerial photographs acquired with a multirotor-type RPAS (DJI Phantom 4), a low-cost and user-friendly equipment. The images were processed using Pix4D Mapper software, enabling the generation of high-resolution Digital Surface Models (DSMs) and orthomosaics. In addition to aerial imagery and three-dimensional modeling, the technique proved effective for quantifying the sediments deposited and/or stored within the channel, allowing the identification of an area of 1.15 km² and an estimated volume of approximately 1,318,312.63 tons along a 4 km stretch of the middle course of the Araguaia River.