F2 - SEM1 - What Is Flooding - 3.2 Flashcards
What are the Natural factors of flooding in China?
F2 - SEM1 - What Is Flooding - 3.2
- Heavy and prolonged rainfall
- Snowmelt
- Climate change
- Low-lying relief
F2 - SEM1 - What Is Flooding - 3.2
Which nature factor is the main cause of flooding in China?
F2 - SEM1 - What Is Flooding - 3.2
Heavy and prolonged rainfall
F2 - SEM1 - What Is Flooding - 3.2
In China, how Heavy and prolonged rainfall causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
In Summer, rainstorms hits the Eastern and Southern parts of China
Moist onshore winds (monsoon winds) and typhoons bring abundant rainfall to the coastal regions
a rapid increase in river discharge
F2 - SEM1 - What Is Flooding - 3.2
In China, how Snowmelt causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
In Spring, snow in the high mountains of western China melts
large amounts of meltwater flow into the rivers,
increase in river discharge
F2 - SEM1 - What Is Flooding - 3.2
In China, how Climate change causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
Global climate change
bring more extreme rainfall events to China
glaciers in the west are melting more quickly due to warmer temperatures
F2 - SEM1 - What Is Flooding - 3.2
In China, how Low-lying relief causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
lower courses of major rivers in East China
flat and gentle relief of region favours the deposition of the sediments
riverbeds become shallower which reduces channel capacity
Rivers overflow easily when heavy rain
F2 - SEM1 - What Is Flooding - 3.2
In China, what are the Human factors causes flooding
F2 - SEM1 - What Is Flooding - 3.2
over-exploiting natural resources
changing land uses
F2 - SEM1 - What Is Flooding - 3.2
In China, what are the Human factors of flooding?
F2 - SEM1 - What Is Flooding - 3.2
- Deforestation
- Reclamation of lakes
- Impermeable urban surfaces
- Poor maintenance of flood defences
In China, how Deforestation causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
no trees to intercept rainwater (vegetation cover reduces)
> infiltration decrease
> surface runoff increases
> raindrop hit the soil directly and soil erosion increases (soil erosion intensifies)
> more soil particles are washed into the river
> river becomes shallower and more prone to flooding
F2 - SEM1 - What Is Flooding - 3.2
In China, how Reclamation of lakes causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
capacity to hold water is greatly reduced
> flooding occurs more easily after heavy rainfall
F2 - SEM1 - What Is Flooding - 3.2
In China, how Impermeable urban surfaces causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
many ground surfaces in China have been packed with concrete (urban development)
> impermeable surfaces prevent the infiltration of water
> surface runoff increases during heavy rain
> flooding occurs when the rainwater cannot be drained away quickly
F2 - SEM1 - What Is Flooding - 3.2
In China, how Poor maintenance of flood defences causes flooding?
F2 - SEM1 - What Is Flooding - 3.2
some flood defences in China are poorly maintained
> during rainstorm, unable to hold the rainwater or even collapse
F2 - SEM1 - What Is Flooding - 3.2
According to USEPA, what is the percentage of water infiltration and surface runoff on concrete surface comparing with soil?
F2 - SEM1 - What Is Flooding - 3.2
water infiltration is 70% less on concrete surface than in soil
surface runoff is 500% more on concrete surface than in soil
F2 - SEM1 - What Is Flooding - 3.2
What are the flood defences that are built to protect cities against flooding?
F2 - SEM1 - What Is Flooding - 3.2
- Dams
- Dykes
F2 - SEM1 - What Is Flooding - 3.2
In general, how do the natural factors and human factors impact?
F2 - SEM1 - What Is Flooding - 3.2
river discharge increases
channel capacity decreases
risk of flooding increases
F2 - SEM1 - What Is Flooding - 3.2
