Vegetation Density Mapping of Urban Solid Waste Landfill Coverage Using Vegetation Indexes Obtained with UAV

Abstract

Objective: The objective of this study is to map the vegetation cover of a municipal solid waste landfill using high-resolution vegetation index images obtained with UAV, as a tool for geotechnical monitoring. Theoretical Framework: The theoretical framework describes the state of the art of vegetation indexes, starting from the first proposal of NVDI by Rouse et al. (1973), through to the NDWI by McFeeters (1996). Additionally, it presents the method of representing radiometric variables, considering that these indexes operate based on the ratio between spectral bands, which are displayed within intervals ranging from -1 to +1. Method: The study used a UAV equipped with MAPIR multispectral camera to capture images of the landfill. NDVI and NDWI indexes were applied to assess vegetation health and coverage. Field control points determined with GNSS-RTK, along with protogrametry software, ensured mapping accuracy, creating high-resolution orhomosaics for monitoring and determining vegetation indexes. Results and Discussion: The results indicate variation in vegetation cover, revealing areas of exposed soil ang vegetation at different stages of vigor, from senescence to full growth. The NDVI and NDWI indexes highlighted regions with water stress and soil exposure, demonstrating the effectiveness of the method in environmental and geotechnical monitoring. Conclusions: It is concluded that the use of UAVs and vegetation indexes are effective for monitoring vegetation health and landfill stability, enanbling the identification of erosion areas and the need for vegetation cover restoration.