Antofagasta, Chile:
Local report from math teacher Mr. Claudio Galindo and coordinator
Mr. Félix Alvarez and their students, Elizabeth and
Carola (age 14-17) from the Club "Grandesideas"
[Great Ideas].
Fog Collectors in the Atacama
Desert
Hi, we
are Elizabeth and Carola, coordinators of the project in Antofagasta.
We are sending you a summary of the presentation we did at
the First English Language Conference on Science and Technology
from the Atacama Desert.
Thanks
for your interest in our work. To see photos, we invite you
to visit our recently updated web site: http://www.grandesideas.cl
.
According to WHO at 2 years old, children
with the worst conditions for water source, water storage
and sanitation were one centimeter shorter than children in
the best conditions.Bacteria and viruses present in the water
are vectors for diseases such as cholera, typhoid, dysentery
and viral hepatitis A.
Chile is the first country where the fog collection system
has been successfully experimented with positive results.
The small desert fishing village of Chungungo on the coast
of northern Chile lies in one of the driest areas of the world
- the Atacama Desert.
The coast of Chile in enveloped in a shroud of persisting
cloud covered for much of the year, know locally as "camanchaca",
the prevailing winds carry this inland creating a continual
fog as it rises over the mountains, but the clouds lacks enough
moisture to produce rains.
Without an adecuate local water supply, the fishing community
was dependent on water brought in by truck from distant wells
at great expense. The supply was often contaminated, as the
truck were also used for transporting other liquids, as well
as unreliable.
Fog collectors are simple, flat, rectangular net of nylon
supported by a post at either end and arranged perpendicular
to the direction of the prevailing wind.
The fog condenses on the mesh and the water drips into a trough.
As fog passes through the net it forms larger water droplets.
The droplets drop down the mesh by force of gravity and drip
into gutters. The water then flows into pipes, which feed
into a container near caleta Chungungo, about four miles away.
The idea of harvesting fog as a source of
drinking water has been studied for decades. In 1987, there
were 50 fog collectors - each one 4 metres wide and 12 metres
long - located on a ridge line above the fishing village of
Chungungo. Today, a total of 75 collectors are expected to
provide more than 40 litres of water per person per day -
compared with just 14 litres before the project began.
The amount of water taken out of the fog is so tiny, and it
is used were it is collected, so it does not damage the delicate
ecosystem of the area.
The success of the Chungungo project has
led to similar projects in Peru, South Africa, the Dominican
Republic, Israel, Cape Verde, the Canary Islands and Nepal.
.
