What is the definition of an Earthquake??
The shaking of the ground
The definition of Volcanic eruption??
Ejection of gases,magma,debris from the mantle through the volcanic vent
What is another word for typhoon ??
Tropical cyclone
The definition of typhoon ??
Severe storms formed over the tropical ocean
Where do typhoons form??
They mainly focus on over the ocean of tropical regions
In what conditions are typhoons formed ?? Name 2
- The temperature of the sea water being higher than 26 degrees Celsius
- Strong air convection current
The definition of Flood??
Overflow of river water/ sea water
The definition of drought ??
No rain for a prolonged period of time / consistently low rainfall
The definition of wildfire ??
Fire occur in woodland which spreads fast and is difficult to control
The definition of Landslide ??
Quick / fast downward slide of slope materials
What are the features of Hong Kong’s relief ??
Hilly 60% of its land is natural slope and there are only a few flatland
What are the locations of the few flatland in hk ?? Name 2
- North western part of new territories
- Along the coast of Victoria Harbour
Where are the highest hills located in hk?? How tall is it ??
They are located in Tai ho sham they are 957 meters tall
What are the 4 reasons of landslide ?? Explain each one
- Heavy Rainfall : rainwater seeps into the solid which increases the burden of the soil which means the cohesion and friction is low
- Less vegetation : rainwater seeps into the solid which increases the burden of the soil which means the cohesion and friction is low
- Rock type : With granite being the most common rock type in hk it is very prone to weathering because of its joints leading it to break up and dissolve into loose weathered materials causing landslide
- Development activities : The cutting and filling of the slope destroys the base structure and increase the burden of the slope
What are the impacts of landslide ??
- Loss of life and property: as the mud will bury the building near the slope
- Traffic congestion: the mud will bury the road surface
- Damage to the water pipes and electricity cables
Prevention of landslides . Name 4 ways
- Drainage channels
- Concrete covers
- Soil nails
- Retaining wall
What does drainage channel do ??
To drain the rainwater
⬇️ amount of rainwater that seeps into the slope
What does concrete cover do ??
To prevent rocks from falling down
Prevent infiltration of rainwater
What does soil nails do ??
Reinforce the slope
⬆️ slope stability
What does retaining wall do ??
It prevents water from infiltrating into soil
Support the slope
What are the other 3 methods of preventing landslide ??
- Regulation of slope development
Meaning all construction projects have to be approved by GEO - Establishing warning signs
The hk observatory and GEO will issue warning signs to aware ppl to stay away from slope during high rainfall or storms - Public education
Government will promote slope safety and organise public education activities
