Avaliação qualitativa da segurança hídrica do abastecimento de municípios fluminenses da Bacia do Rio Pomba

Abstract

The present work has the objective of analyzing the water security in terms of availability and water quality for public supply of the three municipalities of Rio de Janeiro that catch water directly in the Pomba River (Santo Antônio de Pádua, Miracema and Aperibé). Water security consists of analyzing the stress factors with the potential to destabilize the dynamics of environmental management of the Basin and impact the raw water at the catchment point, in quantity and quality, besides evaluating the compatibility of this water with the catchment and treatment system. The analysis was performed for the five stressors proposed in the analytical model developed by the research group "Water Management and Water Safety in Times of Global Environmental Change" of UERJ, of which the author is one of the members. These are: pressure on the environmental conditions of the river basin; Pollution load (pressure on water quality); Water demand (pressure on quantity); Extreme hydrological events; and environmental accidents. For each of these stressors, it was possible qualitatively to verify the potential impacts and associated risks for the quantity and quality of raw water at the point of abstraction of each municipal water supply system. The results indicate that the stressors of greater risk to water security for the urban supply of the municipalities of Santo Antônio de Pádua, Miracema and Aperibé in terms of quantity and quality of raw water at the respective catchment points are as follows: environmental conditions and extreme weather events, followed by pressure on water demand (quantity), pressure on water quality, and environmental accidents (tailings dams) that were considered acceptable risks. On the other hand, the study area is one of the most degraded areas from the environmental point of view in the State of Rio de Janeiro, with little vegetation cover and protected areas. Despite this situation, it was evaluated that the catchment systems of the municipalities present a good adaptive capacity to the level variations of the Pomba River in situations of droughts and floods based on the results obtained with the application of the analytical model; In the same way, it was reported that the treatment systems are being able to assimilate the water quality variation of the Pomba River