Scenario‐based hydrodynamic simulation of adaptive strategies for urban design to improve flood resilience: A case study of the Mingzhu Bay Region, Guangzhou, Greater Bay Area

Abstract

The Pearl River Delta is a complex ecological‐artificial system. The low‐elevation landform and land subsidence make the Guangdong‐Hong Kong‐Macao Greater Bay Area (GBA) more vulnerable to heavy rainstorms with sea‐level rise in the future. Therefore, this study discussed how to optimize the delta‐related built environment based on locality via cooperation between urban designers and hydrology researchers so that urban development in the GBA can adapt to water disasters. First, this study proposed three adaptive spatial strategies for urban design to improve flood resilience: (a) adding more sunken space and rearranging the locations of manholes; (b) adding more retention space to the waterway system; and (c) improving foundation elevation for suitable development intensity. With the prediction of sea‐level rise and land subsidence, four different scenarios were defined. Second, a coupled 1D/2D hydrodynamic model was built for scenario‐based urban inundation simulations. Third, a Python workflow was developed to reveal the water volume exchange, and an ArcMap workflow to realize the impact of inundation. The simulation results show that (a) more sunken space can lower the peak runoff discharges and decrease the runoff coefficient; (b) more retention space can extend the capacity of the urban drainage system and adapt to the rise of sea level; and (c) improving foundation elevation and more sunken green space can direct the surface water to submerge urban land in reasonable order, which can protect the significant infrastructures and development lands. This paper suggests that these adaptive spatial strategies can serve as solutions for resilience development.

Locality and the adaptation of river‐related built environment

“…In light of climate change and rapid urbanization, cities are facing more and more flood risks (Sutton et al, 2022). Some of these cities, located on river deltas, are also vulnerable to heavy rainstorms with sea‐level rise (Lu & Sun, 2021). Three papers in this special issue focus on the sustainable management of flood and water‐related infrastructure in built environments, simulate the dynamic processes of floods and damage generation, and discuss adaptive spatial strategies to reduce flood risks and improve water resilience.…”

“…Garack and Ortlepp (2022) developed a method based on the hydromorphological properties of watercourses to make transferable estimates of the economic damage potential of floods based on ecologically relevant parameters, and considered rivers in Germany and the Czech Republic as case studies. Lu and Sun (2021) suggested more sunken space, more retention space, and higher foundation elevation in order to enhance the flood resistance of delta‐related built environments as solutions for resilience development.…”

Review of Urban Flood Resilience: Insights from Scientometric and Systematic Analysis

“…Understanding the changing laws of urban flooding is of great significance to reduce and adapt to flood risk [ 35 ]. As the urban environment changes, the ecological footprint (EF) metric can also be used to evaluate the sustainable development of the original urban system [ 99 ], to increase the resilience of urban systems to flooding and improve flood protection through urban design in collaboration with researchers, including improving infrastructure levels and increasing hollow areas and drainage capacity [ 100 , 101 , 102 ]. These facilities, from the perspective of a city adapting to this strategy, can be part of the development of an urban flood-toughness plan.…”