DevelopmentsinEarthSurfaceProcesses ...

Climate and Geomorphologic-related Disasters in Latin America 19
more floods than just the exceptional ones are, in reality, severe floods, often
associated with El Niño-ENSO events. In contrast to the Parana River Basin, the
Amazon Basin, the largest and most complex fluvial network in the world, is
characterized by large rivers in a rainforest area with a very low population density.
The largest Amazon cities are concentrated along the main rivers, but they are
strategically located in areas that are not drastically affected by floods. A few cities in
the southwestern Brazilian Amazon, where floods affect some urban areas because
of a lack of urban planning, can be considered exceptions. For example, lowland
rivers produce floods in Rio Branco, the capital city of the State of Acre, which
affect thousands of people, as described in this book by Stevaux et al. (Chapter 13).
However, the recurrence and magnitude of floods are very regular, and river
management is relatively easier to solve. The main problem here is not the
catastrophic characteristics of exceptional floods but insufficient urban planning,
as the cities have grown very quickly, with humans occupying the floodplains
(risk areas).
3.4. Tropical Cyclones and Disasters
The relatively narrow portion of Latin America that extends from Central America
to Mexico is in the unenviable position of being affected by tropical storms and
hurricanes that form both to their west in the eastern Pacific Ocean and to their east
in the Atlantic Ocean (Fig. 1.6). The worst hurricane disaster in Central America
was caused by Hurricane Mitch in 1998, which formed in the Caribbean Sea on
October 22, 1998, and made landfall in Honduras on October 29, 1998. The
hurricane moved very slowly through Honduras and Nicaragua, producing enormous
amounts of rainfall. Some towns received in one day the amount of rainfall
they usually receive in one year, leading to catastrophic flooding and landslides.
Hurricane Mitch is one of the deadliest hurricanes in history, with nearly 11,000
people killed and over 8,000 left missing. In addition to the loss of human life,
flooding and landslides caused an estimated $6 billion in damage. Floods related to
hurricanes and cyclonic circulations had been affecting Central America on a large
scale and part of Mexico as well (Alcántara Ayala, Chapter 4).
Tropical cyclones seldom affect South America, and when they do, they are
confined to the Atlantic Basin, at low latitudes on the coast of Colombia and
Venezuela. About 15 tropical cyclones have affected Colombia and Venezuela in
the past 100 years, with only three making landfall (Tropical Storm Alma in 1974,
Tropical Storm Bret in 1993 and Hurricane Joan in 1988). All three had tropicalstorm
intensity at the time of landfall in Colombia. Hurricane Joan hit Colombia
and Venezuela as a tropical storm in October 1988, causing flooding and landslides
that killed 36 people and left an estimated 27,000 people homeless. No precise data
on Joan’s economic damage or human impact were estimated (Pielke et al., 2003).
The first hurricane ever reported in the South Atlantic was Catarina, which
reached category 2 on the Saffir-Simpson scale just before making landfall in Santa
Catarina State on the southern coast of Brazil on March 28, 2004. Hurricane
Catarina damaged some 36,000 homes, destroyed 1600 homes, and caused severe
damage to agriculture in small coastal cities (Coelho Netto and Avelar, Chapter 12).