Argentina - Sea Rise Risks Are Small But Tangible
Limited development of the Argentine coastline affords a great
opportunity to plan for the future, according to the first quantitative
national assessment of the nation's vulnerability to sea level
rise. While Argentina is less at risk than other countries studied
using Aerial Videotape-assisted Vulnerability Analysis (AVVA)
- Senegal, Nigeria, Uruguay, Venezuela - there are still important
impacts: the erosion of tourist beaches, the erosion and inundation
of low-lying urban, industrial and harbor areas, including the
capital city of Buenos Aires with one million inhabitants, and
loss of wetlands. However, only two percent of the shoreline requires
protection; about 3400 km2, or 0.1 percent of the national land
area is rated vulnerable.
Most tourist resorts are in Buenos Aires Province, stretching
south of the capital city, along sandy beaches. The major impact
of sea level rise would fall on this province, especially north
of the city of Mar del Plata, with destruction of buildings, degradation
of tourist beaches, inundation of farmland and wetlands and less
efficient harbors. This is where 95 percent of the land and value
at risk - about $5.2 to 5.6 billion - is situated. Some damage
would also occur in other tourist resorts along the Atlantic.
Sand extraction for construction is a major activity in this area
and one cause of beach degradation. At Mar Chiquita it is linked
to rapid beach recession of up to 5 meters a year. The beaches
and dunes contain aquifers used by coastal communities for their
fresh water.
Buenos Aires itself, on La Plata River, is on fairly high ground,
although the airport, soccer stadium and university have been
constructed on land along the river recently built up by sediment.
Flooding would have major consequences because of low-lying land
and buildings, and high water levels of 3 1/2 to nearly 5 meters
from extra tropical storms have occurred in the last 50 years
with half a million people suffering property loss and damage.
Erosion would be confined to a small area but with significant
impact on cities, towns and tourist areas.
The most realistic response to sea level rise would be the protection
of important developed areas costing $580 to $1,298 million, from
0.1 to 0.3 percent of Gross National Investment per year. The
major cost, from about half to three quarters, would be spent
on tourist beach nourishment. Some funds would also be used for
the upgrading of harbors which are essential to the country's
overseas trade. The vulnerable wetlands could not be feasibly
protected and would be considered lost. Because of large variability
among the areas at risk, the study suggests that protection might
best be managed at the state level.
Accelerated sea level rise would mostly exacerbate existing problems
that would best be handled by Integrated Coastal Zone Management
measures, considering all problems of the coast including the
rapid urbanization of northern Buenos Aires Province. Possibly
a retreat for wetlands could be planned. Other measures which
might be considered after follow-up studies include appropriate
building setbacks along the Atlantic coast; a vulnerability assessment
to evaluate flooding, sediment availability, and completed or
planned defense works of the Parana delta at Buenos Aires; and
a detailed study of the economic values at risk in the port and
surroundings of Bahia Blanca, a major city in the southern part
of the province with a port built on reclaimed land whose elevation
is barely above mean high tide.
(K.C. Dennis, U. Of Maryland, USA and E.J. Schnack, laboratorio
de Oceanografia Costera, Argentina)
