Transcript Flood Management by Development Control

Is the world getting to be a more
hazardous place?
Professor Adrian McDonald
University of Leeds
Structure
• Some general principles
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Flooding
Fire
Fisheries
Ecology
Real or perceived?
• Unchanged hazards
• Improved observation
• Improved recording
• Improved communication
Definitions
• Hazard
A danger or prospect of harm
• Risk, vt.
Exposure to mischance.
• Management, n.
Trickery, deceitful connivance.
Risk is quantified hazard
• Probability
•X
• Consequence
• = RISK
1 80
Floods
1 60
1 40
Aval an ches /l and s li de s
D ro ugh ts /fa m in es
Number of Events
1 20
Ea rthq uake s
1 00
Extrem e te m peratures
Fl ood s
80
Fo re s t/s crub fires
Vo lcan ic erup ti ons
60
W i nd s torm s
O the r na tura l dis as ters
40
20
0
199 1
1 992
19 93
199 4
1 995
199 6
1 997
199 8
1 999
20 00
Year
Reported Disasters IFRC 2001
Third World and First World
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Impacts in the first world cost money.
Impacts in the third world cost lives.
But
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3rd world flooding is also an opportunity
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Crop diversity
Crop security
These conclusions come from field studies by
Matt Chadwick of the 1998 floods in India.
Population
• Even if the hazards
YEAR
remain the same, the
AD1
impacts will increase
as the population
1750
increases and the value
1900
at risk increases
PEOPLE
300
800
1650
1970
3678
2000
6199
Urbanisation
• The world is
becoming increasingly
urbanised. People and
property are becoming
increasingly
concentrated and
perhaps divorced from
escape options.
Flooding
Is there evidence that flooding is
getting worse?
1991-2000
1981-1990
1971-1980
1961-1970
1951-1960
1941-1950
1931-1940
1921-1930
Decadally-averaged annual precipitation (mm)
900
Data from the
River Ouse
850
800
750
700
650
600
550
500
Decadally averaged annual maximum
floods (m above Newlyn)
7
1991-2000
1981-1990
1971-1980
1961-1970
1951-1960
1941-1950
1931-1940
1921-1930
1911-1920
1901-1910
1891-1900
1881-1890
10
9.5
9
8.5
8
7.5
Number of peaks over 8.058 m threshold
1991-2000
1981-1990
1971-1980
1961-1970
1951-1960
1941-1950
1931-1940
1921-1930
1911-1920
1901-1910
1891-1900
1881-1890
50
45
40
35
30
25
20
15
10
5
0
Annual rainfall (mm)
2000
1500
1000
500
0
1965
1975
1985
1995
Hydrological year
To summarise
• Hidden in a time series of more variable
annual rainfall totals is a picture of
• declining rainfalls yet
• bigger floods
• more floods
Fires
Good intentions?
The fire story
• 2002 was a typical fire
year in Canada
compared against the
ten year average.
Canada recorded
7,824 fires destroying
2,757,174.91 hectares.
Reaction has been to contain fire
• Firebreaks
• Water bombers
Response
• Rapattack teams
(smokejumpers)
• Firecrews
• Aim is control within
an acre
Adverse reaction
• Fires are natural
• Now with a 20 year
history of rapid
response, enlarged fuel
store
• Current fires are
bigger and hotter.
From 10 to 50 1‘000
KW/m flame front
Cause and Effect
Every action has a consequence
In forest operations that consequence may not be seen for a generation
Fireweed may compete with forest
regrowth. Fireweed will attract
insects, grazers and predators.
Sproat Lake, Vancouver Island 1978.
Old growth Douglas Fir consumed 1967
by 7,000 ha Taylor River fire
Natural Regeneration.
Snag trees remain
Fisheries
Sustainable yield
Cost
Value
Catch
Effort
Catch capacity
The development of the potential of a
fleet to catch fish. It is a measure of
capability rather than actual catch.
Development of Catch Capacity
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Spear
Hook
Boat
Speed
Experience
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Communication
Detection
Interpretation
Storage
Technology
Regulation
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Quotas
Implementing the quota
By-catch
Reality