URBAN CONFIGURATION AND WATER BALANCE WITH AQUACYCLE MODEL IN THE BELÉM CATCHMENT, SOUTHERN BRAZIL

Abstract

The influence of anthropogenic activities on drainage basins increases the complexity of hydrological systems in urban watersheds due to the increased amount of impervious surfaces and the interaction between natural and constructed drainage systems. Herein, the aim is to verify how water balance components respond to anthropogenic changes in different configurations of urban space. The study focuses on the Belém catchment, located in Curitiba, Southern Brazil city. Simulations were performed using the Aquacycle model to evaluate the water balance of fourteen Hydrologic Similarity Areas, which were delimited based on the integrated analysis of zoning law, and demographic density data. The results show a direct and linear interaction between an increase in impervious areas with an increase in surface runoff and decreases in infiltration and evapotranspiration, demonstrating the relationship among urban configuration and components of hydrological cycle. Linear regression analysis indicates R² of 0.986 between impervious surfaces and surface runoff, 0.956 for evapotranspiration and 0.934 for groundwater recharge. However, streamflow and baseflow parameters showed no sensitivity to the percentage of impervious surfaces, with R² 0.557 and 0.244, respectively. Finally, the results indicate a significant contribution to the water balance resulting from water-supply system leakage and wastewater discharge into the drainage system.