Determination of saturated areas using TOPMODEL in the Pequeno river watershed, Southern Brazil

Abstract

This work presents the determination of saturated areas in the Pequeno River watershed (104 km2), located in the São José dos Pinhais District, Metropolitan Region of Curitiba, Paraná State, Brazil. We employed the hydrological model TOPMODEL which assumes that the water dynamics are influenced by soil and hillslope characteristics of the entire watershed. It calculates the runoff and the spatial distribution (saturated and unsaturated areas) of the soil humidity in the system throughout the considered time period. The maps of the saturated areas were analyzed taking into account the land use and riparian vegetation (permanent preservation). The computations showed a good adherence between calculated and observed runoff (R²=0.75), thus confirming the model efficiency in regions of humid climate and smooth topography. The simulation results reveal a potential application for environmental planning because they allow the discussion and further orientation for human interventions in the environment based on the understanding of the natural processes.