Case study-Hong Kong Prevention

Question 1

Hard Engineering

Answer 1

The Landslip Prevention and Mitigation Programme (LPMitP), launched in 2010, aims to reduce landslide risks on both man-made and natural slopes. The program upgrades approximately 150 substandard slopes annually, using engineering solutions such as soil nailing, where steel bars reinforce unstable slopes. Additional measures include retaining walls and reinforced barriers to provide structural support. These interventions have reduced landslide occurrences by 75%, significantly improving slope safety and protecting infrastructure. However, the approach is costly and requires continuous maintenance to remain effective.

Question 2

Soft Engineering

Answer 2

To complement hard engineering methods, soft engineering focuses on natural and sustainable solutions to reduce landslide risks. The Geotechnical Engineering Office (GEO) has implemented slope greening techniques, such as planting deep-rooted vegetation to bind soil and prevent erosion. These eco-friendly measures not only stabilize slopes but also enhance biodiversity and improve aesthetics in urban areas. Additionally, public education campaigns have been introduced to promote slope safety awareness, encouraging proper drainage maintenance and community involvement. While these strategies are cost-effective and environmentally friendly, they are less effective in areas with severe slope instability.

Question 3

Forecast

Answer 3

Advancements in landslide prediction technology have played a crucial role in risk mitigation. The city-scale slope digital twin integrates real-time data to monitor ground conditions, allowing for early detection of slope failures. Authorities use machine learning models to analyze rainfall patterns, soil saturation, and slope movements, improving the accuracy of landslide forecasting. Additionally, weather-based early warning systems provide alerts before high-risk periods, enabling proactive safety measures. Despite these advancements, forecasting remains uncertain, especially during extreme rainfall events, which can exceed predicted thresholds and overwhelm preventive measures.

The combination of hard engineering, soft engineering, and forecasting has significantly reduced landslide risks in Hong Kong. However, climate change and rapid urbanization continue to pose new challenges, requiring constant improvements and innovations in slope management strategies.