Análise de suscetibilidade a alagamento no perímetro urbano da sub-bacia do Córrego da Lagoa e os registros de ocorrências no Jardim Pantanal, Dourados – MS

Abstract

The development and consolidation of neighborhoods lacking efficient drainage systems, disregarding geophysical characteristics and not serviced by adequate urban cleaning policies, often result in areas susceptible to flooding. This condition impacts residents directly linked to the system in the short, medium, and long term if no interventions occur. In this context, the urban space of Dourados, located in the southern state of Mato Grosso do Sul, has a history of flooding incidents in neighborhoods like Jardim Pantanal. Confronting these challenges, addressing urban environmental issues becomes essential for promoting social well-being, population quality of life, and sustainable urban growth. This study analyzes the relationship between flood-prone areas in the Sub-basin of Córrego da Lagoa, locations with flooding records, and the conditions of the stormwater drainage network in the urban development of Jardim Pantanal, Dourados, from January 2015 to April 2023. Employing an analytical-descriptive approach, the research utilizes geo-environmental data, remote sensing products, geospatial files of Dourados' urban framework, and applies the hierarchical process analysis method to identify flood susceptibility levels. Additionally, a documentary analysis was conducted as a complementary measure. Advanced techniques such as digital image processing and map algebra were employed, and on-site visits were conducted in the study area. These visits included inspections of stormwater drains and visits to residences affected by flooding, whether officially recorded by civil defense or not. It was observed that a narrow-scale analysis of flooding, relying solely on remote sensing, might paradoxically highlight areas requiring more attention in terms of strategic urban planning. For example, the northeast portion of the Córrego da Lagoa sub-basin exhibited very high flood susceptibility, while the more upstream area showed medium to intermediate susceptibility indices. On the mapped scale, Jardim Pantanal is situated in an area with intermediate susceptibility levels; however, mapping results did not provide a clear explanation for the flooding situation in the neighborhood. Fieldwork data indicated that understanding flooding processes could be enhanced through local analyses. In Jardim Pantanal, obstructed stormwater drains were identified, topographic features and their influence on surface runoff were analyzed, and photographs of urban interventions in residences affected by flooding were taken. The combination of flood susceptibility analysis with the evaluation of points for collecting surface drainage provides a more comprehensive understanding of flood-prone areas in Jardim Pantanal. It is concluded that, based on available data, flooding occurrences are not exclusively linked to precipitation issues. In the study area, a combination of factors influences the possibility of occurrences, including slope associated with the location of stormwater drains. Furthermore, the absence of a cleaning routine, resulting in obstructions in the stormwater drainage system, tends to generate flooding events.