Os desafios da compatibilização entre usos da terra e a segurança hídrica na região de Belo Horizonte – MG: pressões e implicações ambientais na bacia do manancial Serra Azul

Abstract

In 2013, the United Nations (UN) defined the concept of water security as “the ability of a population to ensure sustainable access to water in adequate quantity and quality for survival, human well-being, socioeconomic development, protection against pollution and related disasters to water, and preservation of ecosystems in an environment of peace and political stability”. In Brazil, this concept was adopted in 2019 by the National Water Agency (ANA) to integrate the National Water Security Plan (PNSH), which considers the human, ecosystem, economic and resilience dimensions as benchmarks for analysis. To assess water security in the national territory, the PNSH uses the Water Security Index (ISH), which considers indicators and statistical variables for each dimension. However, water management in the country needs to take into account the particularities of each region, as is the case of the Metropolitan Region of Belo Horizonte (RMBH), which has an integrated supply system supported by subsystems in the basins of the Velhas and Paraopeba. The abstraction of water for this system is of public interest and requires efficient and sustainable management to guarantee the water security of the RMBH. However, the pressure of human activities on public supply reservoirs can compromise the water supply, in addition to affecting other economic activities and ecosystems. In this context, the study focuses on the Serra Azul reservoir basin, responsible for about 16% of RMBH's supply, with the objective of investigating the connections between land use and the environmental quality of this source in relation to water security. Land use and occupation survey methods, water collection and laboratory analysis, as well as field activities were used. The results indicate impacts of human activities on the quality of surface water from the source and the inefficiency of conservation areas in water protection. Reflections are also made on the evolution of pressures in the water sources of the RMBH, identifying four stages along the useful life of the reservoirs.