Conference Agenda

Climate change, by altering rainfall patterns and intensities, exacerbates the risk of pluvial flooding in urban areas. Efficient planning of mitigative measures necessitates advanced methods for urban drainage modelling. Accurate representation of sub-catchments with their actual boundaries is a key aspect in this process. Current methods for sub-catchment delineation often produce sub-catchments encompassing entire urban districts. However, it is well-established that only portions of these districts contribute to runoff, as water from other areas fails to reach inlets due to ground obstacles or soil depressions. This study introduces and evaluates a methodology for delineating high-fidelity sub-catchments in urban areas. The process accounts for ground surface depressions and major obstacles, such as street curbs and buildings, creating a sub-catchment for each inlet in the study area. It also generates key properties required by modelling software e.g. EPA SWMM. The methodology is tested on a combined wastewater system model of the City of Tallinn’s. Results indicate that the proposed method is effective, and the modelling outcomes using high-fidelity catchments are reliable.