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Flashcards in Boscastle Deck (19):
1

when did the flooding occur?

16th August 2004

2

where is it located?

on the coast of cornwall at mouth of the river valency, in the south west of Britain

3

on which day did the meterological agency forecast heavy rainfall?

16th however couldn't say where it would develop

4

how long for and how much rain dropped?

200mm in around 24 hours

5

how did the storm occur?

from a large depression of low pressure over the atlantic . warm air from the sea met with warm sunshine producing huge clouds

6

what type of rainfall occurred?

convectional

7

how does convectional rainfall occur?

warm moist air rising and cooling causing water vapour to condense and rain to fall

8

how much water flowed through Boscastle?

2 million tonnes

9

what was the peak discharge?

100 cumecs

10

how long was the lag time?

3 hours

11

what type of rock is in the area?

Millstone grit - sandstone however was impermeable due to antecedent conditions

12

size and shape of the drainage basin for the river valency?

small and round around 30km^2

13

physical factors?

topography - steep
high relief
antecedent conditions 50mm in 2 hours early afternoon

14

Human Factors?

cars - one trapped under bridge water build up
little flood defences
land use - urbanisation

15

how were local ecosystems affected?

debris from buildings may have damaged the ecosystems

16

how many buildings were destroyed?

6 causing temp loss of economy

17

how many homes were destroyed?

100 homes

18

how much debris was removed in the clean up operation?

1,850 tonnes

19

what was removed out of the river channel and by what method?

vegetation was burned