Modelling Nature-Based Solutions for Urban Stormwater Management

Abstract

This master's thesis focuses on the modelling of Nature-Based Solutions (NbS) at an urban scale for stormwater management. In the context of climate change and the increasing occurrence of urban flooding, alternative solutions are required to complement conventional grey infrastructure. NbS represent a growing research field, as they rely on natural processes to mitigate runoff and partially restore hydrological functions altered by urbanisation.

This work was carried out within the framework of the Water Smart Cities (WSC) project, which aims to develop a software tool to plan and design sustainable stormwater interventions. The main objective of the thesis was to expand the existing library of the WSC solver by implementing and validating new flow control modules (weirs, orifice and perforated riser) through simple tests with predictable outcomes. They were then applied to several case studies derived from the SPW Référentiel de gestion des eaux pluviales, allowing the evaluation of their behaviour in more realistic configurations and comparison with traditional Excel-based approaches.

The solver could be a flexible tool that allows users to model their projects requiring a manageable amount of input data while still capturing key hydraulic processes and system interactions. Compared to simplified Excel-based methods, the solver allows a more refined representation of the system and can help limit excessive oversizing. Overall, this work highlights the potential of the WSC solver as an intermediate tool between simple design methods and highly detailed hydraulic models for urban NbS projects.