Effectiveness of mangroves as nature-based coastal defences in the Pearl River Delta
- 1National Oceanography Centre, Liverpool, United Kingdom (micdom@noc.ac.uk)
- 2Department of Estuarine and Delta Systems, NIOZ Yerseke, Royal Netherlands Institute for Sea Research, Yerseke, The Netherlands
- 3Department of Physical Geography, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
- 4Tianjin research institute for water transport engineering, Ministry of Transport, Tianjin, China
- 5School of Engineering, University of Liverpool, Liverpool, United Kingdom
- 6School of Marine Sciences, Sun Yat-Sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
- 7Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou, China
- 8Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Zhuhai, China
Coastal vegetation can reduce extreme water levels during storm events, but the controlling factors and processes in complex estuary or delta systems are still unclear. This limits an effective implementation of nature-based coastal defences in delta mega-cities in low-lying coastal areas.
To explore the effects of vegetation on storm surge dynamics and currents, we used a Finite Volume Community Ocean Model implementation for the South China Sea and the Pearl River Delta. We numerically modelled how mangroves can offer coastal protection to the large coastal cities located in the delta, such as Guangzhou and Shenzhen, during strong typhoons, like Hato (2017).
Additionally, we analyzed how the effectiveness of mangroves changes under different sea level rise scenarios.
Water level attenuation by mangroves is effective during extreme water level conditions and differences in mangrove forests' properties drive their coastal protection function. The local (within-wetland) attenuation of extreme water levels is more effective with wide vegetation patches and higher vegetation drag. Narrower vegetation patches can still provide non-local (upstream) water level attenuation if located in the upper estuary channels, but their design needs to avoid amplification of water levels in other delta areas.
How to cite: De Dominicis, M., Wolf, J., van Hespen, R., Zheng, P., and Hu, Z.: Effectiveness of mangroves as nature-based coastal defences in the Pearl River Delta, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6519, https://doi.org/10.5194/egusphere-egu23-6519, 2023.
