Fresh water is a life support. Yet over the past half-century the scale and pace of human influences on freshwater systems has accelerated rapidly, along with population and consumption growth. Worldwide water demands roughly tripled.
Pakistan ranks 20th in water resources, 127th out of 142 countries in water availability and 24th out of 140 in severe water stress. Water availability per person in Pakistan today is 1,000 cubic meters, down from 5,600 cubic meters per person in 1947.
Water tables are falling in Pakistan from over-pumping of groundwater. Pakistan has the highest per capita water consumption in the region because of inefficient use. It ranks 8th from amongst 209 countries in groundwater withdrawals. Major rivers now run dry for portions of the year. The impacts of rising water consumption are increasingly visible.
Pakistan has large dams with Tarbela is 5th and Mangla 15th largest in world. For a time, only the benefits of these engineering projects were registered—not their social and ecological costs, in terms of people displaced from their homes, fisheries destroyed, soils contaminated by salts, and aquatic species imperiled. Mangla Dam would silt up in 10 to 15 years.
Pakistan has the 14th highest per capita consumption of water in the world. As much as 97 percent of its water goes to feed its agriculture sector, which is very high. Pakistan’s water table is falling and wells are now being dug deeper and deeper which is not only bringing up salinity but also drying up wells that were shallower.
The exploitation of fossil water in the southern Baluchistan can lead to a disaster. Water is not found until a depth of 1,000 ft is reached in parts of Baluchistan, reflecting that the water table is declining rapidly. The levels of Baluchistan's underground aquifers are dropping at a rate of 3.5 meters annually, and will run out in 15 years, resulting in massive internal displacements.
There are some trends that make the regulation of water resources a much greater need today than it was in the past. The first of these is population growth. Currently the population is 144 million and projected to increase to 260 million by 2050. Added to this, the per capita consumption of water in Pakistan is the highest in the region, due to inefficient use. Urbanization from 1970 to 1994 has increased by 7 percent putting more stress on the resources of cities. Problems are emerging. Water supply development is also reaching its limits. The wells are being dug deeper and deeper, drying up the other wells that are shallower. The Mangla dam may become inoperative in 10 to 15 years time because of silting, and no new large dam is being built.
The most urgent task is to provide all people with at least the minimum amount of clean water and sanitation needed for good health. Yet the large gap in coverage worldwide has almost nothing to do with water scarcity. Globally, providing universal access to 50 liters per person per day by 2015 would require less than 1 percent of current global water withdrawals. There is more than enough water, but so far the political will and financial commitments to provide the poor with access to it have not been sufficient.
Raising the productivity of agricultural water use is critical to meeting people’s food needs as water stress deepens and spreads. In Pakistan agriculture is using 95 percent of our total water, the remaining four to five percent for drinking and industrial use. Of the 565,000 total tube wells in Pakistan, nearly 70 percent are now pumping hard water or saline water, because sweet water has been exhausted. If the drought persists for a year or so, it will mean that there will be more pressure on these tube wells.
To raise the productivity of water, it will be necessary to deliver and apply water to crops more efficiently and to increase crop yields per liter of water consumed. This can be done by using drip-sprinklers and other micro-irrigation systems, changing cropping patterns and growing methods to get more crop per drop, and adopting high-yielding and early-maturing crop varieties. Shifting diets, too, will enable people to satisfy nutritional needs with less water. It takes five times more water to supply 10 grams of protein from beef than from rice, and nearly 20 times more water to supply 500 calories from beef.
There is no mystery about why so much of the water extracted for human use is wasted and mismanaged: the policies that drive water decisions in most cases foster inefficiency and misallocation rather than conservation and sustainable use.
Achieving an optimal balance between meeting human needs and protecting valuable ecosystem functions requires allocating sufficient water throughout the year to sustain those functions. Setting limits on the use of rivers and other freshwater ecosystems is the key to sustainable economic progress because it protects the ecosystems underpinning the economy while spurring improvements in water productivity.
The government should fulfill the obligation to protect the public trust in water by passing laws and regulations that safeguard vital ecosystem functions. It ought to institute groundwater regulations. It also needs to promote more efficient and equitable use of water by using tiered water pricing—where the unit price of water to a user increases along with the volume used. It should restrict water use when necessary—for instance, when river flows drop to low levels. It should also develop markets for water to improve the efficiency of use and allocation. The ability to trade water can help reallocate available supply and encourages users to conserve, because they can sell saved water for extra income.
Pakistan must plan for a sustainable and secure society meeting its water needs without destroying the ecosystems upon the prospects of future generations. (www.asifjmir.com)
Traditional Control Systems - Traditional Control Systems are based on setting standards and then monitoring performance. These systems include three categories of controls: diagnostic ...
6 years ago