Analysis of socio-environmental problems in the La Silla River, Monterrey, México: An approach with UAV geospatial data (LiDAR and RGB)

Abstract. This study examines socio-environmental issues in the La Silla River, situated in the Metropolitan Area of Monterrey (MAM), Nuevo León, Mexico, utilizing advanced technologies such as unmanned aerial vehicles (UAVs) as platforms with onboard sensors, elevation profiles, and a population analysis based on a national database. Like other urban rivers, the La Silla River faces significant challenges, including illegal dumpsites, wastewater discharges, irregular settlements, and solid waste accumulation, all of which are exacerbated by accelerated urban growth. To document these issues, UAVs equipped with an RGB camera and a LiDAR sensor captured high-resolution data, enabling the generation of orthophotos and point clouds, which were then processed for detailed spatial analysis. This information enabled the photo-interpretation mapping of pollution sources and the study of their spatial distribution. Ground-based observations were also collected to compare the effectiveness of field-level data with that of UAV-acquired imagery. A population analysis is presented to understand the social context of the residents living in the river basin, many of whom are vulnerable. This integrated approach strengthens the link between technology and society, offering a valuable and replicable tool for environmental monitoring in urban areas.