Uso do VANT no aterro de resíduos sólidos do Jangurussu – Fortaleza, CE – para fins de análise de risco potencial à erosão

Abstract

With the growth related to new technologies of Remote Sensing, the detail level of the surveys using aerial photographic also evolved. In the search for tools with higher efficiency and lower cost, the use of Unmanned Aerial Vehicles (UAVs) stands out mainly for safety, time and low operating costs in executing a mapping. Therefore, it is intended to use geoprocessing techniques to analyze the geomorphometric variables of the solid waste landfill of Jangurussu - Fortaleza-CE. These variables are derived from a Digital Elevation Model (DEM) produced from the aerial photographic obtained by the use of a UAV and thereby help prevent probable risks by creating a Morphological Erosion Risk Map (MERM). The flight was performed with the DJI’s UAV Phantom 4. Pre-processing flight data was performed in the software Agisof PhotoScan for DEM generation. The modeling of the thematic maps was elaborated using tools of the software ArcGis® 10.3.1, where four geomorphometric variables (slope, aspect and profile and plan curvatures) were extracted from the DEM. These variables analyzed showed in general a result that assist in the interpretation of the geomorphometry at the study area and when integrated it was possible to make the Morphological Erosion Risk Map where it was allowed to classify the areas in degrees of erosion risk. The image processing provided a DEM with a pixel of 63,5 cm, which proves the high spatial resolution defined by the use of the UAV and an easy, fast and low cost data acquisition. When analyzing the erosion risk map, the south, east, southeast and part of the north slope presented high and very high risk levels, which coincide with areas where residences were built inside the limits of the landfill and with a distance of the river banks of approximately 25 meters. Although there were no occurrences of mass movements through the analysis of the images, we cannot exclude the influence of the higher risk slopes and anthropogenic factors causing these movements in a landfill that is disabled but is in a densely urbanized context of a large capital.