Hydrological Modeling of the Catumbela Watershed in Angola Using the SWAT Model

2. Group of Hydrology and Water Resources, Faculty of Engineering, Agostinho Neto University, Angola

Abstract: This project aims to develop a hydrologic model that characterizes the Catumbela Basin and performs water balance. The Soil and Water Assessment Tool (SWAT) model was chosen to test its applicability in small urban watersheds. Using this model, simulated hydrographs were assessed for accuracy over a twenty-year period. Data from January 1944 to June 2019 was used to evaluate the model performance. This work provides a case study for simulating hydrologic processes on a small scale close to the Catumbela outlet. However, the model was insensitive to seasonal water budget drivers such as evapotranspiration. Such a level of hydrological modeling could improve authorities’ understanding the historical flood events, and the lack of hydrological data that has conditioned the scope and success of hydrological models of the basin. The model performance evaluation also showed ranges of values (e.g., Nash Suctile was 0.76 and R2 was 1). The process was extended between 1997 and 2017 with a warm-up period of two years, fifteen years for calibration, and four years for validation. Sequential Uncertainty Fitting model 2 (SUFI2) computed calibration of rules approach on sensitivity analysis. The calibration and validation processes were performed on SWAT-CUP, and results from the uncertainty analysis indicated acceptable values.