Avaliação do comportamento hidrológico de uma bacia de clima tropical úmido sob diferentes cenários de uso e ocupação da terra

Abstract

The monitoring of hydrological processes in coastal watersheds, particularly in the Northeast region of Brazil, plays an essential role. This monitoring is crucial due to the environmental factors and land use determinants that influence proper planning for the development of these areas, especially those contributing to the formation of water reservoirs. However, the limited availability of measured data on water flow and sediment transport for small and medium-sized watersheds is a pressing issue. In this context, the "Event-Based Approach for Small and Unmonitored Basins (EBA4SUB)" model was developed to assist in the assessment of hydrological processes and reduce subjectivity in the analyses. This study focused on the analysis of the hydrological behavior of one of the sub-basins of the Cupissura River, recently selected for the expansion of the water supply system for the metropolitan region of João Pessoa-PB. The analysis was conducted through simulations using a conceptual hydrological model for unmonitored basins and dynamic land use and land cover modeling, aiming to estimate surface runoff in future land use scenarios. The results indicate that, in the three years analyzed, the sub-basin was predominantly occupied by agriculture and pasture, covering from 78% to 81% of the total area. Additionally, the analyses revealed significant losses in forested areas and mosaic agriculture and pasture. Although the simulated hydrographs maintained similar shapes, there were variations in peak flows, indicating a potential increase in flows by the year 2038, suggesting frequent extreme rainfall events in the watershed. This study emphasizes the need for further investigation into the impact of land use and land cover changes in the watershed, considering possible mitigation measures and addressing the uncertainty associated with future projections. Ultimately, it promotes the efficient integration of water resources to ensure long-term sustainability. Finally, the study underscores the importance of considering uncertainties in projections and promotes the efficient integration of water resources to ensure sustainability.