The Impacts
> environmental
> economy
> humanity [1] [2] [3] [4] [5]
[6]
> world/us maps
> eyewitnesses' interviews
> positive impacts
Interactive Timeline
La Niņa
Prediction Methods
The Preparation
About the Site
Archives
Search
Learn Anything?
Forum
______________________
Floods in Peru
Countries along the Pacific coast of South America are often affected by severe weather
during El Niņo years, particularly torrential rain and high winds that lead to flooding
and land slides. As well as disrupting transport, communications, agriculture and
industry, these weather anomalies are a direct threat to life.
During the 1982-83 El Niņo, two normally dry northern Peruvian regions, Piura and Tumbes,
experienced heavy rain for nearly six months. In some regions there had previously been no
rain for 10 years, and adobe buildings literally melted away in the downpour. Road built
on sand were eroded away, and water, electricity and drainage systems broke down. A state
of emergency was declared.
A survey on health during the dry, first six months of 1982 compared with the wet
conditions in 1983, showed that death rates from all causes increased by more than 90
percent in 1983. Increases in respiratory and gastrointestinal diseases were particularly
sharp and the death rate doubled in the 1-4 years-old age group.
Malaria is endemic in the northern coastal areas of Peru. The flooding, combined with an
increase in temperature and humidity, let to a sharp increase in mosquito populations. At
the same time flood damage to property caused increased exposure of the human population
to bites. The result was a malaria epidemic.
On the other hand, the incidence of malaria actually declined in the inland Andean
valleys, and remained stable in the jungle areas, indicating that the dramatic increase
was confined to the regions affected by El Niņo rains and flooding. In the coastal
regions, the increase was 191 cases per 100 000 population. Malaria incidence increased
most in the two regions, Piura and Tumbes, that were most severely affected by flooding.
In the latter, there were 1119 cases of malaria in 1983 compared with a yearly average of
just 20 during the previous 6 years.
Heavy floods are common in many parts of South America, though they are not usually
followed by such increases in endemic illness. The Trinidad and Beni provinces of Bolivia
often suffer flooding, yet no epidemics were reported there even after the heavy 82-83
floods. It may be that where floods are recurrent problem, communities adapt.
In northern Peru, however, only the very old could remember rains as heavy as those in
82-83, and it was very abnormality of the weather conditions that exacerbated the death
rate. For example, a sandy ravine crossed the center of the town of Sullana. Some could
remember water flowing down it 70 years previously, but in the intervening period, shops
and houses and a market had been built along the water way. All these buildings were
destroyed or inundated during the 1982-83 floods.
Intermittent, severe El Niņo induced flooding is probably a long-standing destructive
force in Peru. Michael Mosley of the Chicago Field Museum of natural History believes
systems on the Peruvian plains may have been destroyed by El Niņo rains as early as AD
1100. Without the irrigation systems, the area gradually became arid, as it is today.
Previous Page: El Niņo and Indian Monsoons
Next Page: Rainfall and Drought in Brazil