PROPOSTA DE PROCEDIMENTOS PARA O ZONEAMENTO QUANTO A ADEQUABILIDADE PARA SISTEMAS DE DRENAGEM SUSTENTÁVEIS (SDS) BASEADA EM CARACTERÍSTICAS GEOLÓGICAS E GEOTÉCNICAS: APLICAÇÃO NA BACIA DO CÓRREGO DO GREGÓRIO, SÃO CARLOS (SP), BRASIL

Proposal of procedures for suitability zoning for sustainable drainage systems (SuDSs) based on geological and geotechnical characteristics: application in the Gregório Stream Basin, São Carlos (SP), Brazil

Abstract

This work presents the results obtained with the application of a set of procedures proposed to assess areas for the adequacy of sustainable drainage systems (SUDS) based on data obtained through principles and methods of the engineering geological mapping. The application was developed in the Córrego do Gregório basin, in the urban area of ​​the city of São Carlos with an extension of 19km². The basin was selected because frequent floods have occurred with significant economic and social losses due to changes in the environmental components imposed by the urbanization processes. The assessment was based on the initial division of the area into hillsides and on the analysis of 39 attributes related to the relief, waters, unconsolidated materials, bedrock, potential hazards, anthropogenic aspects and protection zones. The attributes are associated with the infiltration conditions that control the functionality and construction of the systems, subsurface drainability, stability and the potential for groundwater contamination which control the degree of suitability of each land unit. The data obtained through procedures and principles of engineering geological mapping allowed the characterization in terms of the aspects involved, which resulted in the division of the basin into 5 zones of suitability for sustainable drainage systems (SUDS). About 60% of the basin has characteristics of the environmental components that provide different degrees of suitability for systems based on infiltration (Zones 1, 2 and 3), while 25% has more restrictive conditions and with potential for the installation of accumulation and collection systems to control the flow of runoff (Zone 4) and about 15% with restrictions that do not indicate the use of these drainage resources. The results obtained come in favor of the idea that it is possible to adopt these systems and, as a consequence, control the flooding process with low-cost and environmentally efficient technological resources.