WATER- THE MOST ESSENTIAL ITEM OF LIFE

DR.S.M.ALAM
Nov 26 - Dec 02, 2007

Allah has created every living creature from water (Surah Noor-24, Ayat- 45). It is surprising to note that 362 million kilometers or 70 per cent of the global surface is water. The uses of water are numerous and life without water is impossible. A person can live without food for longer than but he cannot live without water or air. Given that 80 per cent of all life forms are found under the oceans, it has been estimated that agriculture uses 47 per cent of fresh water available or about 200 billion litters a day. Water feeds plants and irrigates lands, allowing farmers to produce crops. Industry accounts for 40 per cent of all fresh water use. Industry uses water to transport goods, cool machinery, dispose off waste as power source and refining of natural resources. An example of industry huge water consumption can be seen by the amount of water, it takes to make steel for one washing machine, which are 15,000 litters.

Water is the earth's most distinctive constituent, natural resource and is an essential ingredient of all lives, deficit is one of the most common environmental factors that limit crop productivity. Most of the water in the hydrosphere is salty and much of the fresh water is frozen. It has been estimated that oceans all over the d contain about 97 per cent of the planet's water, in continents of about 2.8 per cent, and the atmosphere about 0.001%, Similarly, about 77 per cent of the water associated with land is found in ice-caps and glaciers and about 22% is found in ground waters, much of which is uneconomical to retrieve. This scenario leaves only a percentage of readily manageable fresh r as a resource of the water supply for the population. Plants transpire about 100-300 times more water the assimilation of CO2 than is required for their the and the production of a usable yield. It has been estimated that 600 kg of water is transpired to produce of dry maize, and to produce 1 kg dry bio mass, ally 225 kg of water is transpired 454 kg of water, n produce 1 kg dried bio mass, they transpire 230 kg water. The world's land surface occupies about 13.2 x 109 ha, of which 7 x I09 ha is arable; only 1.5 x 109 ha of which is cultivated land. The cultivated lands, about 109 ha (23%) is saline and another 0.56 x 109 ha (37%) is sodic. Although, the data are tenuous, it has been estimated that one-half of all irrigated lands (about 2.5 x 108 ha) are seriously affected by salinity or water logging.

Availability of water through efficient water management is the main path for crop production. The Indus Basin irrigation system encompasses the Indus River and its three major water storage reservoirs, 19 barrages/head work, 12 link canals, and 43 canal commands covering about 90,000 villages/chafes. It covers about 39,000 miles. The three major reservoirs Mangla. Tarbela and Chashma were built by Pakistan on signing the World Bank-sponsored Indus Water Basin Treaty between India and Pakistan. Irrigation in this country' depends on both surface and underground water resources. The quantum of water entering the rivers aggregates to about 145 million acres feet per year, of this about 110 million acres feet is transferred look canals for irrigation annually (72 per cent) and remaining 35 million acres feet flows down into the sea, because of lack of storing facilities. The quantum of water entering irrigation watercourses from the canals amounts to 98 million acres feet per annum. Water obtained from 700,000) public and private tube wells for irrigation purposes have been estimated at 45 million acres feet annually. Thus, the total quantum of water entering the watercourses, both from canals and tube wells aggregates to 122 million acres feel annually. Of the 145 million acre-feet, water entering the canals each year, about 28 million-acre feet (i.e. one-fourth) is lost in transit due to a number of factors. Besides, about 40 million acres feet water reaches the field. Also, about 18 million acres feet water is wasted in the fields. Taking into account all the losses as indicated above, only 55 MAP water is normally left for the irrigation of crops. While 90 MAP water annually go waste. Thus the wastage comes to about 62 per cent. The farmers normally need 3.5 MAP water per acre for cultivation, our crops get only 1.5 MAP water per cent.

The magnitude of the problem can be gauged from the fact that the area of productive lands was being damaged by salinity at a rate of about 40,000 ha/year at one stage. On the other hand, our population is increasing at a very fast rate of 3.0 per cent per annum. It is expected that our population will grow to 165.1 million in the year 2007 and we shall need at least 40 per cent to 80 per cent more wheat, edible oil, sugar, milk and wood products at the present rate of consumption.

The two central dilemmas facing agriculture in Pakistan are limited amounts of water of irrigation, and increased salinity. The water budget shows that of the 145 million acres feet of water, which flows annually in Pakistan's rivers, only 12 million acres feet reach the farmer's fields. This figure is supplemented by a further 14 million-acre feet of effective rainfall, and 45 million acres feet tube wells. Leakage of canals and inappropriate irrigation practices have resulted in large in crease in water tables in many areas of Pakistan as : result of this, the Indus plain now has 6.3 million hectares of salt affected land. Both salinity and water logging are the twin menace for the agricultural productivity of the country.

The northern regions of Pakistan are full of world' largest glaciers. They are almost at the height of 4,720 meters above the sea level. They form the biggest function of glaciers on earth giving bind to a pool of Snow Lake, in the surrounding mountains. The Himalayas, the Karakorams. The Hindukush and the Pamirs in the north of Pakistan gave birth to highest peaks and largest glaciers in the world besides the Polar regions. The valleys of mighty Karakorams to the west of Himalayas are more than 1,500 square miles. About 37 per cent of the surface area of Karakoram is under glaciers as compared to 17 per cent of the Himalayas in Nepal, India and China put together and 22 per cent of the European Alps. There are also about 3000 small glaciers and tributaries. The hundred miles of cool, plush, splashing and scintillating winnowing torrents gushing out of these glaciers mingle together to form about 3,180-kilometre long Indus River, which flows to the plains of Pakistan into Arabian Sea, near Karachi.

Water is among the most essential requisites that nature provides to sustain life of plants, animals and humans. The total quantity of fresh water on earth can satisfy all the needs of human population if it is evenly distributed and becomes accessible to all. However, the fact is that water is not evenly distributed or accessible to large sections of global population. This defines the central resource management problem. Water is a substance of paramount ecological, economic and social importance. Water is the essence of life and a constant supply of clean, healthy water is essential for all citizens of the country. It is the most important element in the figurative pipeline of life and with more than 80 per cent of every living thing (from human body to a lonely plant in a desert) on planet earth will, rather literally wither away. Water acts as a carrier, supplying nutrients to our cells and delivering waste products to our excretory organs. The human body contains about 45 to 60 per cent of water. Infants have the highest and the elderly the lowest amount of water in their tissue. To lead a healthy life,drinking of sufficient amounts of uncontaminated water, which contains adequate amounts of mineral. Rivers, springs, wells, the sea and other sources differ in mineral content.

Safe drinking water is essential for good health and is a pre-requisite to the control of diseases most commons in developing countries. One of the main objectives of management of water is to provide safe water to people in adequate quantities for drinking, food preparation, and personal hygiene, at a low cost keeping in view the economic level of the community. Disposal of wastewater creates another problem. In humid area pools of such water breed mosquitoes and in case of open drains, human and animal wastes can contaminate the groundwater, which can be protected by proper and effective management of water resources.

Drinking water is one of the human body's primary and basic need, so much so that a man can go on living for up to 50 days or more without food, but it will be almost impossible for him to live, if he is not given water for more than two days. The criteria for drinking water are different from those as fixed for crops. The World Health Organization (WHO) has fixed certain standards. The US Public Health Services Standards are also very similar to those of the WHO. The total dissolved solids (TDS) being considered desirable for drinking purpose are 500 mg/l, and those permitted are 1000 mg/l. The recommended permissible limits and in some cases considered necessary are presented below (mg/l).

A drinking water must be safe to drink, pleasant to taste and usable for domestic purposes. Polluted or contaminated water contains microorganisms. Chemicals or other industrial waters. Many bacteria (Salmonella, Enterococcus, Pseudomonas) and many other harmful microorganisms are found in water. Same are harmless and other cause diseases such as typhoid fever, meningitis is, bloody diarrhoea, dysentery, cholera, food poisoning, urinary tract infections, gastrointestinal diseases, vomiting, serve headache and muscular abdominal cramps, etc. One type of bacteria grows in iron bearing water and help in precipitating iron oxide or rot.

For safe drinking and maintaining the general health, the water should be boiled for at least 25 minutes because boiling removes germ: boiled water should be filtered before drinking and covered while cooling containers for storing water must b cleaned each time before filling. According to WHO standards, one pound of chlorine should be used for one million gallon of potable water in normal season, while its quality should almost be doubled in the rainy season.

TABLE
COMPOSITION OF DRINKING WATER

CONSTITUENTS

PERMISSIBLE

LIMITS

EXECUTIVE

 

WHO

AMP

HEALTH

Total dissolved solids (TDS)

500

500

1500

Iron (Fe)

0.3

0.3

1.0

Manganese (Mn)

0.1

0.1

0.5

Copper (Cu)

1.0

3.0

1.5

Zinc (Zn)

5.0

15.0

15.0

Calcium (Ca)

50

---

150.0

Magnesium (Mg)

50

125.0

150.0

Sulphate (SO4)

200

250.0

400.0

Chloride (Cl)

200

250.0

400.0

Lead (Pb) Toxic Substances

0.1

---

 

Arsenic (Ar)

0.2

0.05

---

Selenium (Se)

0.05

0.05

---

Chromium (Cr)

0.05

0.05

---

Fluorine (F)

1.0

1.5

---

Nitrates (NO3`)

10.0

---

---

CONCLUSION : Water is one of the most fundamental of natural resources that; country must harness in its efforts for rapid economic development. The role of water in the development process can not be over-emphasized. The demand for water in the country has increased tremendously over the year: and will continue to increase in view of the accelerating pace of population growth, urbanization, and industrialization. Comprehensive water resource management is necessary for the benefit of citizens in the country.