A framework to support flood prevention and mitigation in the landscape and urban planning process regarding water dynamics

Abstract

The urbanization process heavily changes the natural landscape, increasing built areas and impervious rates, consequently aggravating floods and suffering from the co-related degradation. Recent initiatives regarding sustainable drainage and river restoration seek a compromise solution between cities and nature. In this context, this research examines a possible analytical framework for urban planning and design of flood control alternatives, using a multifunctional open space system that incorporates water dynamics into current and future urban solutions. This framework starts with a diagnosis of the current situation, analyzing three main aspects: urban floods and their consequences; urban plans and legal environmental constraints; and available open spaces and multifunctional opportunities. Then, a set of guidelines is proposed to articulate urban needs with environmental limits, intending to help in the design of urban flood control alternatives, while increasing environmental value and retrofitting urban vicinity. These guidelines include multi-scale solutions in the watershed context, using sustainable urban drainage concepts in multifunctional open spaces, which can also act as environmental connections and protective fluvial parks. Next, the current situation is taken as reference and a hydrodynamic mathematical model is used to map the behavior of possible scenarios developed to represent future conditions driven by the proposed guidelines. This proposal is applied in an exploratory case study in the Rio de Janeiro Metropolitan Region to validate the proposed premises. The obtained results show that a multifunctional open space system, supported by an orderly and sustainable land use, was able to reduce significantly the water levels in the main river, diminishing flooded areas and responding in a more resilient and less risky way.