Author Topic: Sources of Fresh water  (Read 4441 times)

engineer

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Sources of Fresh water
« on: February 11, 2010, 10:39:40 AM »
The quantity of water required for a community depends upon:

1.Forecasted population
2.Types and variation in demand (e.g. seasonal variation)
3.Maximum demand (Per day/Per month)
4.Fire demand
5.Rural demand and supplies
6.Appropriate / Available technology
Main sources of water are

■Surface water sources: Lakes impounding reservoirs, streams, seas, irrigation canals
■Ground water sources: Springs, wells, infiltration wells
Above are the common sources of clean drinking water, other different sources of drinking water are

Merits of surface sources
Merits of ground water sources
1.Being underground, the ground water supply has less chance of being contaminated by atmospheric pollution.
2.The water quality is good and better than surface source.
3.Prevention of water through evaporation is ensured and thus loss of water is reduced.
4.Ground water supply is available and can even be maintained in deserted areas.
5.The land above ground water source can be used for other purposes and has less environmental impacts.
Demerits of ground water source
1.The water obtained from ground water source is always pressure less. A mump is required to take the water out and is then again pumped for daily use.
2.The transport / transmission of ground water is a problem and an expensive work. The water has to be surfaced or underground conduits are required.
3.Boring and excavation for finding and using ground water is expensive work.
4.The modeling, analysis and calculation of ground water is less reliable and based on the past experience, thus posing high risk of uncertainty.

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Sources of Fresh water
« on: February 11, 2010, 10:39:40 AM »

engineer

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Re: Sources of Fresh water
« Reply #1 on: February 11, 2010, 10:39:57 AM »
Quantity of water:

The quantity of water available at the source must be sufficient to meet various demands and requirements of the design population during the entire design period. Plans should be made to bring water from other sources if the available water is insufficient.

Quality of water:

The water available at the source must not be toxic, poisonous or in anyway injurious to health. The impurities should be as minimum as possible and such that, can be removed easily and economically.

Distance of water supply source:

The source of supply must be situated as near to the city as possible. Hence, less length of pipes needs to be installed and thus economical transfer and supply of water.
The source nearest to the city is usually selected.

Topography of city and its surroundings:

The area or land between the source and the city should not be highly uneven i.e. it should not have steep slopes because cost of construction or laying or pipes is very high in these areas.

Elevation of source of water supply:

The source of water must be on a high elevation than the city so as to provide sufficient pressure in the water for daily requirements. When the water is available at lower levels, then pumps are used to pressurize water. This requires an excess developmental and operational tasks and cost. It may also have breakdowns and need repairs.

Water quality

■Impurities present in water and their health significance
■Water quality standards set by U.S and W.H.O
■Water quality tests

anthonygree

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Sources of Fresh water
« Reply #2 on: April 28, 2010, 08:32:33 PM »
Nature has blessed Pakistan with adequate surface and groundwater resources. However, rapid population growth, urbanization and the continued industrial development has placed immense stress on water resources of the country. The extended droughts and non-development of additional water resources have further aggravated the water scarcity situation. Consequently per capita water availability has decreased from 5600 m3 to 1000 m3/annum. The increasing gap between water supply and demand has led to severe water shortage in almost all sectors. The water shortage and increasing competition for multiple uses of water adversely affected the quality of water. In this regard, the results of various investigations and surveys by several agencies had indicated that water pollution has become a serious problem in Pakistan. Most of the reported health problems are directly or indirectly related to water. The quantitative and qualitative concerns of water call for an action plan for efficient development, utilization and monitoring of the water resources of the country.

samshamolian

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Re: Sources of Fresh water
« Reply #3 on: May 17, 2010, 11:56:39 PM »
Most of the water in the hydrosphere at any given time is in the oceans; most of the remaining fresh water is stored in ice sheets. Little water is found in lakes and streams. A portion of the fresh water on the continents-both surface water and ground water is diverted for human use.

Canada is often called a "water-rich" nation, as we are the stewards of 9 % of the world's renewable fresh water supply, and we have the longest ocean coastline of any country. In addition, Canada seems to have the second largest continental shelf along our coast. The fact is, however, in a global context, Canadians are the second-highest users and wasters of water in their day-to-day lives. Our high per capita water usage, coupled with other stressors such as population growth, has increased pressure on Canada's freshwater resources. Also, while we enjoy one of the highest standards of clean water in the world, pollution also remains an important problem in some of our waters. In some areas, people cannot swim or eat the fish they catch. In other areas of Canada people have suffered severe health problems and even died as a result of not having access to clean water.


WilliamHenry

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Re: Sources of Fresh water
« Reply #4 on: August 24, 2010, 06:47:36 AM »
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose.It is most frequently used by reference to a set of standards against which compliance can be assessed. The most common standards used to assess water quality relate to drinking water, safety of human contact and for the health of ecosystems.