Hong Kong - Landslip Prevention and Mitigation (LPMit) Project at Mid-levels under LPMit Programme (LPMitP)

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Challenges

The LPMitP is the first of its kind, so the framework for the programme had to be developed from scratch. Furthermore, the region in question is particularly complex and requires a deep understanding of complex geological and groundwater conditions and potentially unstable terrain. The new infrastructure also needed to account for the projected increase in rainfall due to climate change; to address this challenge and prepare for worsening conditions, the programme has evaluated a range of possible scenarios through a quantitative risk assessment. The state-of-the-art projection is that extreme rainfall in Hong Kong, with a return period in excess of 1,000 years, could trigger more than 50,000 landslides and stress testing using this scenario in different parts of Hong Kong has provided much insight into the catastrophic impact on the community and the crisis situation.

Actions

Before implementing any risk mitigation works on hillsides, the LPMit project team consulted the District Council and local residents to address identified objections and concerns. The programme also used a risk-based priority ranking system to plan follow-up studies for vulnerable areas to ensure the efficacy and cost effectiveness of their retrofits.

 

The LPMitP seeks to minimise the threat posed by landslides, by constructing risk mitigation measures including innovative barriers. By design, the barriers are able to resist debris flows and boulders in the event of a landslide, and suitable drainage provisions and reinforcement can make the terrain more resilient to rainfall.  The project has set annual targets, aiming to retrofit 150 man-made slopes, carry out 100 safety-screening studies of man-made slopes, and mitigate the risk of 30 natural hillside catchments each year.

Projected Outcomes

Given the extensive attention paid to risk management, the LPMitP is well-prepared to adapt to new challenges brought forth by climate change. The project protects City residents from potentially fatal landslides and alleviates both direct and indirect economic losses, making Hong Kong a more resilient and safer city. This systematic programme serves as an example of effective long-term thinking and sets an example for other climate adaptation initiatives in Hong Kong and beyond. Recognizing that this project is also an educational and knowledge management opportunity, the LPMitP also produced technical publications, guidebooks, an app, and videos to showcase landscaping case studies and best practices in slope engineering.