title: Sustainable Stormwater Management in Complex Catchment: An Integrated Modelling Approach
Creators: name: Lin, Xiaohua
Publisher: name: University of Liverpool Repository
Year: 2029

description: Urbanisation and climate change pose challenges for stormwater management through exacerbating flood risks and introducing uncertainties in precipitation patterns. While Low Impact Development (LID) or Best Management Practice (BMP) approaches aim to address these issues, effective implementation remains a research priority, especially for heterogeneous catchments under changing conditions. Existing identification methods for LID placement focus on static indicators rather than dynamic hydrological processes influenced by diverse environmental factors. Large-scale hydrological modelling can overcome these limitations by quantifying spatial and temporal variations. This study proposes an integrated modelling-statistical framework to identify priority regions for LIDs within large, complex catchments considering multiple interactive factors. 

The Soil and Water Assessment Tool (SWAT) hydrological model is calibrated and validated for Qinhuai River Basin in China. Statistical analyses of monthly and annual runoff coefficients derived from model outputs delineate hydrologically sensitive areas based on runoff potential rather than static attributes alone. Several LID and BMP scenarios are then evaluated through the LID/BMP module to assess mitigation of flood risks across priority zones. Climate projections from six global climate models of the Coupled Model Intercomparison Project Phase 6 (CMIP6) force the model to project changing hydrological responses under different Shared Socioeconomic Pathways. Results demonstrated that the integrated modelling-statistical approach effectively captured dynamic hydrological sensitivities for the identification of priority zones. Urban expansion increased runoff markedly, whereas agricultural conversion decreased paddies’ contribution, though paddies remained dominant in evapotranspiration. All climate models projected amplified precipitation/runoff trends regardless of the socioeconomic pathway, with the most significant increases under SSP370. Ensemble analysis captured overall patterns, while individual models required bias correction. Validation of identified sensitive areas and management strategies remains crucial due to data limitations. Addressing gaps through targeted data collection and model refinements can strengthen predictive capabilities and applications. Overall, findings offer foundations for prioritising sustainable stormwater investments to enhance urban resilience under uncertainty.

Continued methodological refinements integrating long-term and finer-scale observational data and bias correction of individual climate models are needed to validate impact assessments under different pathways and provide more reliable regional forecasts supporting local adaptation planning. Expanding the variable scope to explore water quality, aquatic ecosystems and socioeconomic dimensions of sustainable management would broaden the understanding of management implications. Comparing catchment characteristics across diverse regions through trans-basin studies would generate transferable insights supporting diagnostic assessments, adaptive management efforts and resilience-building initiatives worldwide.