The rapid expansion of urban areas has heightened concerns about urban flooding due to increased paved surfaces, aging drainage infrastructure, and rising rainfall intensity. Researchers employed a GIS-driven hybrid modeling approach combining the Soil and Water Assessment Tool (SWAT) and Storm Water Management Model (SWMM) to analyze flood behavior in the Wakad Watershed of the Mula River within the Pimpri Chinchwad Municipal Corporation (PCMC), Pune District, Maharashtra, India. The SWAT model used historical rainfall data from 1993 to 2023 for calibration and validation of hydrological simulations at the catchment level. To simulate urban drainage during the major flood events of 2007 and 2019, SWMM was integrated with the SWAT outputs. Model performance was evaluated using the Nash-Sutcliffe Efficiency (NSE) and Root Mean Square Error (RMSE). The hybrid SWAT–SWMM model showed excellent predictive accuracy, with NSE scores above 0.85 and peak flow estimation errors under 3%. Notably, the combined optimization reduced RMSE by 41%, marking a significant improvement over individual models and emphasizing its suitability for urban flood research. Integrating SWAT and SWMM within a GIS framework provides a powerful decision-support tool for urban planners, water managers, and policymakers. This approach delivers more precise, spatially detailed flood forecasts, supporting proactive drainage planning, climate-resilient infrastructure development, and sustainable resource management in expanding cities.
Jawale et al. (Thu,) studied this question.