Case study-Hong Kong landslides causes/impacts

Question 1

Why Hong-Kong?

Answer 1

The entrepôt of Hong Kong has long been associated with landslides due to rapid urbanisation, steep topography and a sub-tropical climate bringing warm, wet conditions in summer.

Question 2

Causes?

Answer 2

1. Heavy Rainfall:
   
   • Hong Kong’s subtropical climate brings intense rainfall, especially during typhoon seasons. Rainfall rates exceeding 70 mm per hour can saturate soil, reducing its stability and triggering landslides. 
2. Steep Topography:
   
   • Over 60% of Hong Kong’s terrain has slopes steeper than 15 degrees, and 30% steeper than 30 degrees. This rugged landscape is inherently susceptible to landslides, particularly when combined with heavy rainfall. 
3. Human Activities:
   
   • Urban Development: Rapid urbanization has led to construction on unstable slopes, increasing landslide risks. The 1972 Po Shan Road landslide, for example, was exacerbated by such development, resulting in significant casualties and property loss. 
   • Deforestation: Removal of vegetation for construction diminishes root systems that stabilize soil, heightening landslide susceptibility.

Question 3

Impacts?

Answer 3

1. Loss of Life and Injuries:
   
   • Landslides have caused numerous fatalities and injuries. For instance, the 1972 landslides led to at least 156 deaths, highlighting the severe human toll of such disasters. 
     2. Economic Consequences:
   • The financial burden includes infrastructure repairs, emergency response costs, and economic disruptions. The 2023 rainstorm and subsequent landslides caused extensive damage, leading to significant economic losses. 
     3. Environmental Degradation:
   • Landslides result in habitat destruction, loss of biodiversity, and soil erosion, leading to long-term ecological consequences.

Question 4

Human Impacts?

Answer 4

1. Increased Vulnerability:
   
   • Construction on hilly terrains due to housing pressures has placed communities in high-risk areas, making them more susceptible to landslides. 
     2. Policy and Planning Challenges:
   • Balancing urban development with environmental conservation poses significant challenges. Inadequate land-use planning can exacerbate landslide risks, necessitating comprehensive strategies to mitigate such hazards.
     3. Community Displacement:
   • Landslides can force evacuations and displace residents, leading to social and economic hardships. The 2023 rainstorm, for example, caused landslides that isolated communities, requiring government intervention for evacuations.