Abordagem multicritério híbrida dos recursos hídricos no semiárido: Proposta metodológica de gestão sistemática

Abstract

The water scarcity in the Brazilian semiarid region is a multifaceted crisis, involving environmental, social, and economic aspects. Efficient water management in this area becomes crucial to meet present and future needs sustainably. The thesis proposes an innovative methodological approach, using hybrid models to identify and assess the vulnerability of water systems, classifying management alternatives in terms of quantity and quality of water. This approach aligns with the Sustainable Development Goals (SDGs) proposed by the United Nations and the Systematic Management of Water Resources (SMWR). This study focused on watersheds located in the semiarid region of Northeast Brazil, considering the uniqueness of this scenario. The methodology is divided into three fundamental stages aligned with the targets of SDG 6 Clean Water and Sanitation. Initially, a hybrid multicriteria model, based on GIS, is employed to map regions vulnerable to water scarcity in both donor and recipient regions of water in the semiarid. Subsequently, a hybrid model combining flow network modeling and entropy-multicriteria is developed to assess water demand management alternatives at a reservoir scale. Finally, hybrid multicriteria models are developed and compared for the selection and classification of wastewater treatment technologies. The results indicate that vulnerability to water scarcity in the donor region for transposition may be more critical than in the recipient region, influenced by the choice of weighting method. The results of flow network simulations, based on the reference scenario (A0), showed that the system without management measures has a human demand fulfillment frequency of only 65% of the simulated period. The classification of alternatives suggests mechanisms for water conservation and increased efficiency in water use, emphasizing the need for rational, modernization, and sustainable approaches. The hierarchy of wastewater treatment ranked Filtration Gardens as the top-performing alternative, while the Activated Sludge system occupied the lowest position. This hybrid approach can guide decision-makers and water managers in the studied regions, providing management measures in response to the proposed models.