Existing drainage systems have limited capacity to mitigate future climate change-induced flooding problems effectively. However, some studies have evaluated the effectiveness of integrating Water-Sensitive Urban Design (WSUD) with existing drainage systems in mitigating flooding in tropical regions. This study examined the performance of drainage systems and integrated WSUD options under current and future climate scenarios in a sub-catchment of Saltwater Creek, a tropical catchment located in Cairns, Australia. A combination of one-dimensional (1D) and two-dimensional (1D2D) runoff generation and routing models (RORB, storm injector, and MIKE+) is used for simulating runoff and inundation. Several types of WSUDs are tested alongside different climate change scenarios to assess the impact of WSUD in flood mitigation. The results indicate that the existing grey infrastructure is insufficient to address the anticipated increase in precipitation intensity and the resulting flooding caused by climate change in the Engineers Park sub-catchment. Under future climate change scenarios, moderate rainfall events contribute to a 25% increase in peak flow (95% confidence interval = [1.5%, 0.8%]) and total runoff volume (95% confidence interval = [1.05%, 6.5%]), as per the Representative Concentration Pathway 8.5 in the 2090 scenario. Integrating WSUD with existing grey infrastructure positively contributed to reducing the flooded area by 18–54% under RCP 8.5 in 2090. However, the efficiency of these combined systems is governed by several factors such as rainfall characteristics, the climate change scenario, rain barrel and porous pavement systems, and the size and physical characteristics of the study area. In the tropics, the flooding problem is estimated to increase under future climatic conditions, and the integration of WSUD with grey infrastructure can play a positive role in reducing floods and their impacts. However, careful interpretation of results is required with an additional assessment clarifying how these systems perform in large catchments and their economic viability for extensive applications.
Details
Title
Impact of Climate Change on Water-Sensitive Urban Design Performances in the Wet Tropical Sub-Catchment
Authors
Sher Bahadur Gurung - James Cook University
Robert J Wasson - James Cook University
Michael I Bird - James Cook University
Ben Jarihani (Corresponding Author) - University of the Sunshine Coast, Queensland, School of Science, Technology and Engineering
The field data used in this study are available from the corresponding author upon request.
Grant note
The authors gratefully acknowledge the support of James Cook University for providing funding through the International Research Training Program (IRTPS-081386F) for this research. Additionally, the authors would like to acknowledge the Cairns Regional Council (PD23041 Saltwater Creek Flood Mitigation Project) and the Queensland Government Department of Environment and Science for funding this project. Furthermore, the authors would also like to thank the Hunter Research Grant [00117] for providing the additional funds to purchase the software tools.
Organisation Unit
School of Science, Technology and Engineering; Sustainability Research Cluster