Influence of infiltration and soil moisture models on urban hydrological model reliability

Abstract

This study investigates the influence of infiltration and soil moisture models on the reliability of urban hydrological models, focusing on guiding the selection of Blue-Green Infrastructure (BGI) for stormwater management. Infiltration models such as Horton and Green-Ampt, combined with dynamic representation of soil moisture, fundamentally affect predictions of runoff generation and flood risks in urban catchments. Given that the Kinawataka catchment contains compacted urban soils, heterogeneous pervious–impervious patterns, and frequently saturated low-lying areas, accurately modelling infiltration and soil moisture becomes essential for improving flood prediction reliability. The results from these hydrological models provide critical insights that help in choosing appropriate BGI solutions by indicating how infiltration and soil moisture conditions impact urban runoff and flood mitigation potential. This approach supports optimized BGI selection to enhance urban flood resilience and sustainable water management strategies. The study aims to enhance the understanding of runoff and infiltration processes within the Kinawataka catchment by conducting rainfall simulations and applying hydrological modelling techniques. This research provides a novel contribution by jointly evaluating infiltration models and soil moisture dynamics specifically for an urban Ugandan catchment, an aspect that has received limited attention in previous studies. The research will generate reliable data to support the strategic selection and design of Blue-Green Infrastructure (BGI) interventions that are appropriate for the local urban context. Ultimately, by clarifying how infiltration and soil moisture representations influence hydrological model reliability, the study contributes to improving flood forecasting, model calibration, and urban flood resilience in data-scarce and rapidly urbanizing cities such as Kampala.