Today, thanks to a very simple technique, we can collect the water contained in the fog and provide the villagers two or three times more water than they used before and this, at a lower cost. The thick fog (camanchaca), which spreads almost permanently along the coast of Chile and creates sheets of stubborn mist when the prevailing winds blow from the sea and cross the mountains, makes it possible to use this technique.
http://archive.idrc.ca/nayudamma/fogcatc_72f.html
Fog sensors
Introduction
implications
prerequisites
Potential users
Contact points
Resources
Introduction
In Chungungo, Chile, a small village in one of the driest regions in the world, water is a precious commodity. Transported by truck from distant wells, it has long been normal to use it drop by drop. Water, often contaminated, was very expensive and was responsible for poor hygienic conditions, the proliferation of diseases and insufficient food production.
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With financial assistance from IDRC, Chilean and Canadian scientists have developed an inexpensive and sustainable water supply system: a polypropylene net stretched between two poles, much like on a gigantic volleyball court. Water droplets form on the cracks crossed by the fog. They then fall into gutters which supply a reservoir and a network of pipes in Chungungo.
Chungungo is currently supplied by 80 sensors that produce an average of 10 liters of water per day. Meanwhile, researchers have developed and tested a new sensor prototype that is easy to build and maintain. Twenty sensors based on the new concept were installed on a new site in 000.
The success of the Chungungo project has aroused the interest of several other countries for this new technique. We installed fog sensors in the province of Islay and in the hills of Manchay, on the coast of Peru, in collaboration with the Instituto Nacional de Investigación Agraria y Agro-Industrial of the Ministry of Agriculture and the Asociación TECNIDES. In Ecuador, systems are in service at Pululahua and Pachamama Grande. Trials underway in certain regions in Namibia and South Africa are aimed at determining whether these sensors can be used there.
implications
* Water from the fog completely replaced the water previously transported by truck to Chungungo. Since the installation of the fog sensors in 1992, the availability of water has exceeded expectations. The population expected that the new technique would allow it to increase its consumption from 27 liters per person per day to 33 liters. Each now consumes around 340 liters per day on average and there is enough water to grow vegetables for local consumption and sale. This technique improved the state of health and raised the level of income of the population. (By comparison, Canadians consume an average of XNUMX liters of water per day.)
* Fog sensors provide a more reliable and safe water supply. In the past, tankers sometimes broke down or were delayed if the road to Chungungo was impassable. The same trucks were also used to transport other liquids which could leave residues in the tank and contaminate the water delivered to the village.
* The water quality in Chungungo now meets all the criteria of the Chilean government and the World Health Organization. Locals say the water looks better and tastes much better.
* Today, the Chungungo water supply network is administered entirely by the community. The tariffs imposed on consumers allow the network to self-finance its operation and maintenance. The Ministry of Public Works of Chile is responsible for the system, providing institutional support and the investments necessary for future expansion and improvement.
* Previously poor, the village now draws other benefits from the system. Electricity was installed there in 1993 and houses have been built around a new tourist area called Villa Canadá. Chungungo also attracts vacationers, indisputable proof of the improvement in the quality of life in the village.
* Two ten-day courses organized in Chungungo allowed participants from Peru, Ecuador, Namibia and Chile to acquire practical training on site selection, construction, operation and economics of fog sensor technology. In 1994, IDRC also sponsored an international technology promotion workshop in Serena, Chile, attended by representatives from ten interested countries.
* Chungungo's success has prompted other organizations (including the European Union) to fund similar fog sensor projects and to publicize the benefits of this technique elsewhere. IDRC co-sponsored the first International Conference on Mist and Mist Collection in Vancouver in July 1998.
prerequisites
This technique is best suited to areas where there is constant fog that can be intercepted inland. Fog should prevail during the season when water is most needed. Five other conditions are also important: a mountain range that has an average altitude of at least 500 meters; the main axis of the chain should be perpendicular to the prevailing winds (which increases the volume of water collected); the water collection point should be as close as possible to the target community; the presence, on the other side of the mountains, of a vast basin where the high temperatures during the day help to attract air from the ocean which crosses the mountains, is certainly an asset; the direction of the prevailing winds must be constant throughout the year.
Potential users
Communities in all regions of the world (usually in coastal regions or on islands, but sometimes inland) where rainfall is low and atmospheric conditions resemble those described above. Besides Chile, Peru and Ecuador, the regions that could benefit the most include the Atlantic coast of southern Africa (Angola, Namibia), South Africa, Cape Verde, China, Yemen eastern, Oman, Mexico, Kenya and Sri Lanka.