Adequabilidade e modelagem de sistemas de drenagem urbana sustentável na perspectiva do assentamento precário.

Abstract

In cities in the developing world, dense, precarious, and informal settlements are common. In these areas, the occurrence of intense rainfall and the increased impervious surfaces have led to disastrous flash floods, harassing roads, houses and public facilities. However, the main urban drainage solutions adopted by the government, in order to improve these areas, frequently focuses in highly centralized drainage systems based on the 19th-century sanitary philosophy. Sustainable urban drainage systems (SUDS) are an alternative to enhance stormwater management and runoff control, providing benefits related to social and environmental domains. This study simulates SUDS techniques (permeable pavements, infiltration trenches, biorretention systems and rainwater harvesting systems) at the Ramadinha catchment, located in the city of Campina Grande. This catchment is composed of precarious settlements and received urban drainage interventions financed by the government program PAC-UAP. We identify different spatial urban components and configurations throughout the Ramadinha catchment in order to target strategic locations for SUDS implementation. We also present a modeling framework of SUDS implementation, using the Storm Water Management Model (SWMM) to simulate different SUDS scenarios, introduced both in public and private areas. During the simulation, it was observed the spatial distribution of flooding hotspots and the decreasing of the total flooding volume in the urban configurations, for each scenario. Besides, it was analyzed the impact of flooding in the access to public facilities necessary to the community daily life. The results demonstrate that SUDS measures implemented in public spaces are not enough to completely avoid flooding in the denser parts of the catchment. In such cases, measures must be implemented in private lots due to the reduced amount of available public spaces. Such evidence shows that one of the key elements for flash floods management in consolidated dense and precarious urban settlements is the integration between SUDS measures and the mobilization and engagement of local inhabitants in planning and decisionmaking.