Venkatachalam, A. J. (Alicia Jane) (2010) Environmental assessment of the south coast of Sri Lanka, with special reference to the 2004 tsunami. PhD thesis, University of Warwick.

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Abstract

Following the 2004 tsunami in Sumatra, Sri Lanka experienced >30,000 confirmed
deaths and disruption of livelihood. Damage to coastal ecosystems was less than
anticipated, especially in comparison with reported impacts from unsustainable
development. This research examines tsunami related damage against a background of
anthropogenic pressures. Fishery changes were determined through interview of three
generations of fishers targeting frigate tuna. Significantly higher values for best day’s
catch and largest specimen ever caught were obtained by older fishers than younger ones.
Values were also significantly higher during early years, providing clear evidence of
resource decline and the ‘shifting baseline syndrome’. Most fishers reported posttsunami
decline in frigate tuna, but mainly from a larger new generation of fishers, rather
than extra boats provided by aid money or (direct or indirect) biophysical impacts from
the tsunami. The number of boats post-tsunami increased significantly in all research
areas, which could result in further catch decline.
The perceptions of 500 Sri Lankan fishers about the influence of risk factors on tsunami
death toll and house damage are quantified). Mangroves, coral reefs and sand dunes
afforded protection against tsunami damage (67–94% of fisher responses), as did
housing and roads. Fishers believed rivers/estuaries, concave coastlines and hotels
exacerbated impacts. For comparison, multi-variable models for death toll, housing
damage, inundation area and distance are built, incorporating both natural and
developmental risk factors. Bathymetry is the only factor significantly associated with
all indicators of impact. Mangroves and marsh were not a significant factor in final
multivariable models. However, in terms of inundation, sand dunes were identified as
protective, while bodies of water exacerbated damage. The extent of agreement and
variance between modelling results and the opinions of fisher questionnaires is critically
examined.
Research findings highlight the need for better coastal management. While the role
mangroves in tsunami protection remains equivocal, their known role in providing many
other ecosystem services suggests that mangroves warrant greater conservation attention
in Sri Lanka, in the face of coastal development pressures. Coastal policy and
conservation priorities should be influenced by scientific research (e.g. the tsunami
model in this thesis) as well as traditional ecological knowledge and opinions from indigenous people. Factors shown to provide tsunami protection often cannot be altered
by human intervention (e.g. topography and bathymetry). However, sand dunes could
potentially be preserved to reduce future impacts. Tsunamis are rare events and further
research should be carried out to determine which risk factors are important for more
frequent events (e.g. monsoon). The needs of coastal communities should always remain
paramount in considerations of future tsunami and environmental policies.

Item Type:	Thesis (PhD)
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences
Library of Congress Subject Headings (LCSH):	Indian Ocean Tsunami, 2004, Tsunami damage -- Sri Lanka, Fishers -- Sri Lanka, Coastal zone management -- Sri Lanka
Official Date:	October 2010
Dates:	Date Event October 2010 Submitted
Institution:	University of Warwick
Theses Department:	School of Life Sciences
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Price, Andrew, 1950-
Extent:	xii, 153, [53] leaves : ill., charts, maps
Language:	eng

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