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ECOSYSTEM RESTORATION
FOR DISASTER PREVENTION
AND MITIGATION
Natural ecosystems that help prevent disasters include natu-
ral vegetation and forests on slopes and hill sides and catch-
ment forests hindering erosion and slowing passage of water
from rainfall (Zhao
et al
., 2009), wetlands providing buffers for
floods (Costanza
et al
., 2008), riparian zones influencing wa-
ter chemistry (Dosskey
et al
., 2010); mangroves and coral reefs
for waves, tsunamis and storms (Badola and Hussain, 2005;
UNEP, 2007; 2009), vegetation in drylands hindering erosion
(UNEP, 2006; Lal, 2009), forests and mangroves in estuar-
ies buffering flood effects (Tallis
et al
., 2008) not to mention
the function of ecosystems in buffering further land degrada-
tion and providing live-able conditions for people and animals
worldwide by protecting the local climate.
The value of coastal wetlands for hurricane protection has
been estimated at 250–51,000 USD/ha/year, with an average
of 8240 USD/ha/year, with coastal wetlands in the US current-
ly providing storm protection services valued at 23.32 billion
USD annually (Costanza
et al
., 2008). Mangroves have been
estimated to reduce damage of storm floods to impoverished
by an average of 33.31 USD/household compared to unprotect-
ed villages with damages over 153.74 USD/household (Badola
and Hussain, 2005).
Potential damage from storms, coastal and inland flooding and
landslides can be considerably reduced by a combination of
careful land use planning and maintaining/restoring ecosys-
Ecosystems play a crucial role in reducing, mitigating and avoiding major hazards and di-
sasters worldwide – while their destruction and degradation may both exacerbate or even
cause catastrophes: Every year 270 million people in the world, 85% of them in Aisa are
exposed to natural disasters and some 124 000 people are directly or indirectly killed.
Affected
Killed
Africa
22 173 000
7623
Americas
14 315 000
38 281
Asia
801 634 000
38 735
Europe
1 273 000
1245
Table 3:
Relative vulnerability to floods across continents (1998–
2008) (World Disaster Report 2009)
Source: FAO 2001, Benniston 2003, Jianchu
et al
. 2007, USAID 2007, UNU-IAS
2008, Eriksson
et al
. 2009 a, b. ICIMOD 2009, Pacific Disaster Center 2009, World
Disaster Report 2009.
Type of disaster
Flash floods
Seasonal floods
Droughts
All natural hazards
WORLD
No. affected/year
100 000 000
80 000 000
230 000 000
ca. 270 000 000
No. killed/year
5000
4000
30 000
100 000
ca. 124 000
Table 2:
Number of people affected by natural disasters in Asia
(row 1–4) and the world (row 5) 1998–2008
tems to enhance buffering capacity. Planting and protecting
nearly 12,000 hectares of mangroves cost USD 1.1 million but
saved annual expenditures on dyke maintenance of USD 7.3
million.(Tallis
et al
., 2008; TEEB, 2009).