Mekong Flashcards
1
Q
How many nations does the Mekong cross?
A
- 6 nations
2
Q
What is the source of the Mekong River?
A
- Tibetan Plateau
- meltwater
- also sustained by monsoon rainfall
3
Q
Why is the Mekong important?
A
- Supports 60 million people directly
- many more indirectly
- Hosts rich biodiverse community
- Used for HEP generation
4
Q
Who manages the Mekong?
A
- only lower course is managed
- by Mekong River Commission
- China is not a member
- proposed 10 year ban on building of dams
- has very limited funds
- thus has no way of actually enforcing
- China has held back water from flowing through member states when it is most needed
5
Q
How large is the scale of HEP construction on the Mekong River?
A
-
China has completed 8 dams
- 5 more under construction
- 11 planned
-
Laos and Cambodia have 2 under construction
- 9 planned
6
Q
What benefits do dams come with?
A
- HEP
- generates income
- can be essential for landlocked countries such as Laos
7
Q
What are the downsides of HEP in the Mekong?
A
- Only meets 8% of projected power needs
- Harms ecosystems
- migratory fish cannot move freely
- hinders natural processes
- Pollutants are not flushed out downstream
- less fertile sediment carried by river downstream
- worse for farmers as they depend on sediment to act as fertiliser
- other farmland may be flooded instead
- may increase regional tensions between countries
8
Q
How has an increasing population in Vietnam affected the Mekong?
A
- 90% of Vietnamese forest has been cut down
- severely increased local runoff levels
9
Q
What effect has China’s building of dams had on the Mekong?
A
- reduced sediment load in the lower Mekong from 160MT to 75MT in 15 years
- causes widespread riverbank erosion
- less sediment carried by river
- less settles on floodplain when flooding
- reduced floodplain fertility
10
Q
How has the water quality of the Mekong been changed?
A
-
Lanping Lead-Zinc mine
- Mercury and arsenic have been released
- Mekong dolphins have died from bacterial illnesses caused by these chemicals
-
Phnom Penh
- Urban sewage and rubbish has been dumped into the Mekong
- resulted in cultural eutrophication
- build up of nitrogen and phosphorus in water
-
Pesticides run off from fields
- resulted in algal blooms
- water hyacinth outbreaks
- reduce water oxygen levels
- resulted in carp and shrimp levels dropping off in Vietnam, Cuulong Delta
- bad for subsidence fishers
11
Q
How has the flow of the Mekong been changed and what affect has it had?
A
- Mekong flow has reduced
- By damming + use of water
- flow into Tonle Sap lake has been reduced
- harder for people in Phnom Penh to get fresh drinking water
12
Q
How has trade been enhanced along the Mekong?
A
- Sandbars and rocks within river have been cleared
- allows ships and large ferries to travel along Mekong
- However, results in devastating floods as these structures would have obstructed water flow
13
Q
What effect has building had on the Mekong Delta?
A
- 17 million people live in delta
- 18cm subsidence in delta over past 25 years
- resulting in seawater encroachment into rice padddies
14
Q
What is cultural eutrophication?
A
- Eutrophication due to human induced disposal of rubbish