Northern Metropolis and Sea Level Rise
Prof. Christine LOH, Chief Development Strategist, Institute for the Environment, HKUST
Prof. Alexis LAU, Director of Institute for the Environment, HKUST
Prof. Zhongming LU, Assistant Professor, Division of Environment and Sustainability, HKUST
An urgent problem for all coastal cities is sea level rise (SLR) triggered by changes to the Earth’s climate. Hong Kong and the South China region will face more extreme weather, such as super typhoons and heavy rains. Storm surges during typhoons can cause flooding and coastal damage.
The Northern Metropolis is an exciting development project, still at its conceptual design stage. One issue it must address is how to deal with SLR.
The HKSAR Government has been considering SLR for some years. For example, Civil Engineering and Development Department (CEDD) first studied the implications of climate change on the design of coastal structures nearly 10 years ago and has updated its design manual for port-related works over time.
CEDD has also been conducting studies on what Hong Kong needs to do to adapt to climate change. It sets up the interdepartmental Climate Change Working Group on Infrastructure in June 2016 to coordinate studies of works departments in adapting to climate change, oversee the revision of design standards and examine the scope of enhancement works needed for strengthening the resilience of existing government infrastructure.
At HKUST, our CARe2018 Conference in 2018 made specific suggestions on studies needed for the HKSAR Government to formulate policies and projects related to climate adaptation. CEDD and Drainage Services Department (DSD) were partners for the event. In 2019, CEDD commissioned a consultancy study on the relevant risks faced by Hong Kong. We are pleased that CEDD just published in April 2022 the study report entitled “Study of Coastal Hazards under Climate Change and Extreme Weather and Formulation of Improvement Measures – Feasibility Study”.
This is an important document because it identified 26 vulnerable coastal low-lying and windy residential locations in Hong Kong. Areas of concern in the Northern Metropolis development plan are in parts of Yuen Long and Sha Tau Kok. The document also contained suggested measures that could alleviate the hazards.
The HKSAR Government should now encourage wide dissemination of this Study before making decisions on developing policies and implementation projects.
The Study recommends the government to adopt a progressive adaptive approach in designing coastal infrastructure that has “design allowance” to enable flexibility for changes to be made as conditions change or if impacts due to climate change are different from that anticipated, since climate impacts are highly non-linear and locally specific. Naturally, continuous monitoring of changes would be needed to assess risk levels.
As a general principle, the approach makes sense from an engineering perspective. Importantly, the Study also points out climate adaptation projects require both the public and private sectors to cooperate, and the public also needs to be engaged as they are property owners and users.
This is the right time for a thorough discussion about climate change and SLR in Hong Kong. It would be even better if there could be opportunities for the Greater Bay Area (GBA) to discuss its vulnerable areas for the whole region since the region is becoming increasingly integrated. This would need the support of the GBA authorities.
Some projects are already going ahead – in particular, the flood prevention Yuen Long Barrage Scheme . Beyond flood prevention, DSD is designing this large project to include “nature-based solutions (NBS)” so that it incorporates biodiversity considerations, for example revitalisation of water bodies to enhance the local environment quality of the existing Yuen Long nullah, as well as beautification to enable public enjoyment.
The eventual government policy should support strong NBS elements for all infrastructure projects. This means biodiversity becomes a key element, as biomimicry designs have been proven to work in Hong Kong and elsewhere in the world.
At HKUST, we look forward to continuing to work with the HKSAR Government.