Book P.49-54

Question 1

what are natural hazards?

Answer 1

they are natural events that cause the loss of life and property.

Question 2

in what cases are ‘natural hazards’ considered as natural events?

Answer 2

if they happen in remote places and cause no harm to people.

Question 3

please name the three types of natural hazards.

Answer 3

geological hazards, climatic hazards, and biological hazards.

Question 4

define geological hazards.

Answer 4

they are caused by geological processes and earth movement.

Question 5

define climatic hazards.

Answer 5

they are caused by extreme climates.

Question 6

define biological hazards.

Answer 6

they are caused by living organisms.

Question 7

name three examples of geological hazards.

Answer 7

volcanic eruption, landslide, tsunami

Question 8

name four examples of climatic hazards.

Answer 8

drought, flooding, wildfire, typhoon

Question 9

name an example of a biological hazard.

Answer 9

locust swarm.

Question 10

What are the most common extreme weather conditions in summer?

Answer 10

rainstorms and typhoons.

Question 11

describe rainstorms.

Answer 11

strong winds and heavy rains.

Question 12

what is the cause of rainstorms?

Answer 12

they are brought by high summer temperatures and moist onshore monsoons.

Question 13

how are we affected by rainstorms?

Answer 13

large amounts of rainfall may disrupt traffic, and cause flooding or landslides.

Question 14

how do we prevent the losses of rainstorms?

Answer 14

to reduce losses and damage, the Hong Kong Observatory will issue rainstorm warning signals when there is a rainstorm.

Question 15

Please name and describe the three rainstorm warning signals.

Answer 15

amber rainstorm warning signals: heavy rain (>30mm/hr)
red rainstorm warning signals: heavy rain (>50mm/hr)
black rainstorm warning signals: very heavy rain (>70mm/hr)

Question 16

why can’t typhoons go to high pressure areas?

Answer 16

this is because they are low-pressure systems.

Question 17

describe typhoons.

Answer 17

they are strong tropical cyclones with dense clouds, very strong winds, heavy rain and sometimes thunder and lightning.

Question 18

where is the calmest place in a typhoon? describe the place.

Answer 18

the eye of the typhoon. it is calm and has no clouds at the center of the typhoon, and the pressure is the lowest there.

Question 19

what are spiral rain bands?

Answer 19

they are the strips of clouds or rain surrounding the eye.

Question 20

when is the typhoon season?

Answer 20

summer.

Question 21

describe the air motion of a typhoon, and its relationship with the earth’s rotation.

Answer 21

east to west; it is the opposite of the earth’s rotation, which is west to east.

Question 22

Where are most of the typhoons that affect Hong Kong and the eastern coast of Asia are formed?

Answer 22

they are formed over the ocean near the Philippines.

Question 23

Where is the tropical area?

Answer 23

the area between the tropic of cancer and the tropic of capricorn.

Question 24

what are the ‘birth places’ of typhoons?

Answer 24

warm tropical oceans.

Question 25

typhoons formed in the _______________/ ________________ hemisphere of the earth move ________________/ ________________/ ________________/ ________________.

Answer 25

northern, southern, north, northwest, west, southwest

Question 26

describe the formation process of a typhoon.

Answer 26

1. warm ocean surface with 26.5°C or above
2. moist air is heated by the warm ocean
3. air cools and condenses to form clouds
4. condensation releases heat to the surrounding air
5. air is kept warm and continues to rise, forming towering clouds
6. rising air results in a low-pressure centre
7. more air moves into low-pressure centre
8. air spirals upwards as it rises
9. intense low air pressure sucks in more moist air, causing very strong winds
10. a typhoon is formed

Question 27

on average, there are _____________ typhoons in Hong Kong each year.

Answer 27

5-7

Question 28

when a typhoon hits a place, it will ________________ ________________ ________________, ________________ and ______________ ____________ ___________. at its worst, typhoons can cause ________________, and ______________________________ and ________________.

Answer 28

disrupt economic activity, transport, people’s daily life

injuries, loss of life, property

Question 29

heavy rain brought by typhoon _________________________________________________________________ such as ________________ and _______________.

Answer 29

may sometimes trigger other natural hazards, flooding, landslides

Question 30

prevention for the destruction typhoons cause:
—
—
—
—

Answer 30

good monitoring and warning systems
typhoon-proof buildings
better land use planning
educating people to take precautionary actions

Question 31

Name an example of how did the Hong Kong Observatory establish good monitoring and warning systems.

Answer 31

warning signals

Question 32

name four examples of the facilities of typhoon-proof buildings.
—windows
—compared with
—walls
—built

Answer 32

windows are tempered glass with shatter-resistant film
compared with two-sided roofs, winds can flow smoothly over four-sided roofs; which prevents roofs from being lifted away by winds from any direction
walls are made of concrete to increase strength
build on stilt to protect the house from flooding.

Question 33

name an example of how the government engages in better land use planning.

Answer 33

moving settlements away from the shoreline, and further inland, to reduce the effects of storm surges

Question 34

name an example of how the Observatory educates people to take precautionary actions.

Answer 34

the observatory website.

Question 35

name the two remedies established by the government for the damage inflicted after a typhoon.

Answer 35

well-trained rescue teams and emergency aids

open temporary shelters to those affected

Question 36

how are hailstorms formed?

Answer 36

—when the land is very hot, air is heated up; water droplets aren’t heavy enough to fall so instead they continue to rise, and as they continue to rise they collect more droplets and become heavier. when they finally rise to the air where it is below 0 °C, they finally get heavy enough to fall. this is why hailstorms happen in summer