Venezuela debris flow Flashcards
1
Q
debris flow defintion
A
coarse regalith (including boulders) and other debris. rates of flow reach 50km/h. associated with heavy rainfall. Produce alluvial flows along mountain fronts
2
Q
year took place?
A
1999
3
Q
physical factors leading to debris flow
A
- between 8-19th decemeber, slow moving cold front deposited 914mm rain
- seaward facing slopes are very steep=rapid run-off and streams have high energy
- igneous rock on mountains had been weathered=easily erode and add sediment to debris flows (fine clays)
4
Q
human factors leading to debris flows
A
- government blamed corrupt politicians from previous government who allowed shanty towns to grow in steep valleys surrounding the coast and the capital
- rapid population growth had concentrated urban development on the alluvial flows (6.3% in 10 years risen)
- poor education/lack of preparedness
- deforestation had increased run off and erosion
5
Q
social impacts
A
- > 150,000 made homeless
- 10,000-50,000 dead, no real finalised figure
6
Q
economic impacts
A
- ruined the countries tourist industry
- destroyed roads, bridges, factories, telecommunications, buried crops
- international airport Caracos closed
- damage estimated a >$3 billion
7
Q
environmental impacts
A
- mudslides were 30ft deep
- trees uprooted
- debris deposited
8
Q
short term responses
A
- search for survivors in the mud flows
- provided emergency relief e.g. accommodation, water, purification tablets, food and medicines
9
Q
long term responses
A
- government want people to move from overcrowded coast to interior
- rebuild thousands of homes, expand airport and construct canals diverting rivers away from communities
- towns devastated/swept away were turned into parks, bathing resorts and other outdoor facilities
- rivers aren’t suitable for settlements unless checked dams are built in the mountains to hold back debris flows and floods
