Fog collection
Encyclopedia
Fog collection refers to the collection of water from fog using large pieces of vera trough below the canvas.
, atmospheric
water vapour from the air naturally condenses on cold surfaces into droplets of liquid water known as dew
. The phenomenon is most observable on thin, flat, exposed objects including plant leaves and blades of grass. As the exposed surface cools by radiating its heat to the sky, atmospheric moisture condenses at a rate greater than that of which it can evaporate, resulting in the formation of water droplets.
(MSC) began constructing and deploying large fog collecting devices on Mount Sutton in Quebec
. These simple tools consisted of a large piece of canvas
(generally 12 m long and 4 m high) stretched between two 6 m wooden poles held up by guy wires, with a long trough underneath. Water would condense out of the fog onto the canvas, coalesce into droplets, and then slide down to drip off of the bottom of the canvas and into the collecting trough below.
's National Forest Corporation (CONAF) and Catholic University of Chile
. With funding from the International Development Research Centre
(IDRC), the MSC collaborated with the Chileans to begin testing different designs of collection facilities on El Tofo Mountain in northern Chile
. Once perfected, approximately 50 of the systems were erected and used to irrigate seedlings on the hillside in an attempt at reforestation. Once vegetation became established, it should have begun collecting fog for itself, like the many cloud forests in South America, in order to flourish as a self sustaining system.
project is unclear, but approximately five years after the beginning of the project, the nearby village of Chungungo began to push for a pipeline to be sent down the mountain into the town. Though this was not in the scope of CONAF, which pulled out at this point, it was agreed to expand the collection facility to 94 nylon mesh collectors with a reserve tank and piping in order to supply the 300 inhabitants of Chungungo with water.
The project, completed in 1992, initially achieved a spectacular success, with an average production of 15,000 litres of water per day (peaking at 100,000 liters) that could be stored or piped to the village for use in drinking, bathing and irrigating
. The accomplishment achieved high publicity, with frequent quotes from the townspeople, for whom water was dangerously scarce before, calling the collectors a “miracle.”
Unfortunately, the IDRC reports that ten years later in 2002, only nine of the devices remained and the system overall was in very poor shape. On the other hand, the MSC oddly states in its article that the facility was still fully functional in 2003, but provides no details behind this statement. In June 2003 the IDRC reported that plans existed to revive the site on El Tofo.
and central Chile
, while still others are under evaluation in Guatemala
, Haiti
, and Nepal
, this time with much more emphasis on the continuing involvement of the communities in the hopes that the projects will last well into the future. Villages in a total of 25 countries worldwide now operate fog collection facilities. There is also still potential for the systems to be used to establish dense vegetation on previously arid grounds. Overall, it appears that the inexpensive collectors will continue to flourish.
Technical explanation
Through a process known as condensationCondensation
Condensation is the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of vaporization. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition....
, atmospheric
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
water vapour from the air naturally condenses on cold surfaces into droplets of liquid water known as dew
Dew
[Image:Dew on a flower.jpg|right|220px|thumb|Some dew on an iris in Sequoia National Park]]Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening...
. The phenomenon is most observable on thin, flat, exposed objects including plant leaves and blades of grass. As the exposed surface cools by radiating its heat to the sky, atmospheric moisture condenses at a rate greater than that of which it can evaporate, resulting in the formation of water droplets.
Historical Origins - Natural or assisted fog collection
The organised collection of dew or condensation through natural or assisted processes is an ancient practice, from the small-scale drinking of pools of condensation collected in plant stems (still practised today by survivalists), to large-scale natural irrigation without rain falling, such as in the Atacama and Namib desert. Several man-made devices such as antique stone piles in the Ukraine, medieval "dew ponds" in southern England or volcanic stone covers on the fields of Lanzarote have all been thought to be possible dew-catching devices.Modern Development - Artificial fog collection
In the mid-1980s, the Meteorological Service of CanadaMeteorological Service of Canada
The Meteorological Service of Canada , also known as "The Canadian Weather Service", is a division of Environment Canada, which primarily provides public meteorological information and weather forecasts and warnings of severe weather and other environmental hazards...
(MSC) began constructing and deploying large fog collecting devices on Mount Sutton in Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
. These simple tools consisted of a large piece of canvas
Canvas
Canvas is an extremely heavy-duty plain-woven fabric used for making sails, tents, marquees, backpacks, and other items for which sturdiness is required. It is also popularly used by artists as a painting surface, typically stretched across a wooden frame...
(generally 12 m long and 4 m high) stretched between two 6 m wooden poles held up by guy wires, with a long trough underneath. Water would condense out of the fog onto the canvas, coalesce into droplets, and then slide down to drip off of the bottom of the canvas and into the collecting trough below.
Background
The intent was simply to use these devices to study the constituents of the fog that they collected. However, their success sparked the interest of scientists in ChileChile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
's National Forest Corporation (CONAF) and Catholic University of Chile
Pontifical Catholic University of Chile
The Pontifical Catholic University of Chile is one of the six Catholic Universities existing in the Chilean university system and one of the two Pontifical Universities in the country, along with the Pontifical Catholic University of Valparaíso. It is also one of Chile's oldest universities and...
. With funding from the International Development Research Centre
International Development Research Centre
The International Development Research Centre is a Canadian Crown Corporation created by the Parliament of Canada that supports research in developing countries to promote growth and development...
(IDRC), the MSC collaborated with the Chileans to begin testing different designs of collection facilities on El Tofo Mountain in northern Chile
Norte Grande, Chile
The Norte Grande is one of the five natural regions into which CORFO divided continental Chile in 1950. It borders Peru to the north, the Pacific Ocean to the west, the Altiplano, Bolivia and Argentina to the east, and the Copiapó River to the south, beyond which lies the Norte Chico natural...
. Once perfected, approximately 50 of the systems were erected and used to irrigate seedlings on the hillside in an attempt at reforestation. Once vegetation became established, it should have begun collecting fog for itself, like the many cloud forests in South America, in order to flourish as a self sustaining system.
Result
However, the success of the reforestationReforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....
project is unclear, but approximately five years after the beginning of the project, the nearby village of Chungungo began to push for a pipeline to be sent down the mountain into the town. Though this was not in the scope of CONAF, which pulled out at this point, it was agreed to expand the collection facility to 94 nylon mesh collectors with a reserve tank and piping in order to supply the 300 inhabitants of Chungungo with water.
The project, completed in 1992, initially achieved a spectacular success, with an average production of 15,000 litres of water per day (peaking at 100,000 liters) that could be stored or piped to the village for use in drinking, bathing and irrigating
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
. The accomplishment achieved high publicity, with frequent quotes from the townspeople, for whom water was dangerously scarce before, calling the collectors a “miracle.”
Unfortunately, the IDRC reports that ten years later in 2002, only nine of the devices remained and the system overall was in very poor shape. On the other hand, the MSC oddly states in its article that the facility was still fully functional in 2003, but provides no details behind this statement. In June 2003 the IDRC reported that plans existed to revive the site on El Tofo.
Cause of Failure
The reason for the failure of this project to achieve sustainability can be attributed to many factors. Because the project started off on a different path, the final route that it took was disorganized and lacked clear objectives once the facilities were built. The villagers of Chungungo formed a committee to see to the maintenance and repair of the collectors, funded by collections from the village households, but, ironically, the new water supply caused the population of the village to triple and the committee was unable to acquire the supplementary funds to expand the array of collectors and the reservoir, which would have solved any new water shortage problems easily and cost effectively. It is also suggested that this and other methods of water supply are shunned by the people of Chungungo and towns in other developing countries, who feel that collecting one’s own water lacks prestige and think that the state should pay for such services. In fact, this is exactly what the people of Chungungo wanted as of 2003 – a pipeline costing around USD 1 million to be built from Los Choros river, 20 km away.International Use
Despite the apparent failure of the fog collection project in Chungungo, the method has already caught on in various localities around the world. Nowadays the International Organization for Dew Utilization organization is working on foil-based effective condensers for regions where rain or fog cannot cover water needs throughout the year. Shortly after the initial success of the project, researchers from the various participating organizations formed the nonprofit organization FogQuest, which has set up operational facilities in YemenYemen
The Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....
and central Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, while still others are under evaluation in Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
, Haiti
Haiti
Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island...
, and Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
, this time with much more emphasis on the continuing involvement of the communities in the hopes that the projects will last well into the future. Villages in a total of 25 countries worldwide now operate fog collection facilities. There is also still potential for the systems to be used to establish dense vegetation on previously arid grounds. Overall, it appears that the inexpensive collectors will continue to flourish.
Sources
- International Development Research Centre article on the fog collection project
- Meteorological Service of Canada article on fog collection project
External links
- Fog Harvesting, chapter from Source Book of Alternative Technologies for Freshwater Augmentation in Latin America and the Caribbean, UNEPUnited Nations Environment ProgrammeThe United Nations Environment Programme coordinates United Nations environmental activities, assisting developing countries in implementing environmentally sound policies and practices. It was founded as a result of the United Nations Conference on the Human Environment in June 1972 and has its...
International Environmental Technology Centre - The Fog Collectors: Harvesting Water From Thin Air
- FogQuest: Sustainable Water Solutions, Canadian organization, historical information on fog collection projects in developing countries
- How Peru is netting water supplies BBC News