WATER SOURCES IN PAKISTAN

M .Nadeem Ashraf

Soil & Environmental sciences

Faculty of Agriculture, Rawalakot

Ravi

IntroductionWater covers 71% of the earth’s surfaceWater moves continually through a cycle of evaporation, precipitation and runoffEssential for all forms of life.

Water sourcesSources from which water is available for water supply schemes are called water sources.The most common sources of water for irrigation includes:Surface Water (Rivers, Reservoirs and Lakes).Ground water.

the chanab

Surface waterWater in a river, lake or fresh water wetland.Naturally replenished by precipitation, lost through discharge to the oceans, evaporation, and subsurface seepage.The total quantity of water in a system may depends onStorage capacityPermeabilityRunoffPrecipitation and evaporation rateHuman activities can have large and devastating impact on these factor byincrease storage capacity by Constructing damDecrease it by draining wetlands

Total quantity of available water depends on seasons like

1)Winter2)SummerHumans can cause surface water to be “lost” (i.e.

become unusable) through pollution.

DesalinationArtificial process by which Saline water is

converted into fresh waterDistillation and reverse osmosisExpensive process

Water availabilityVary a lot over the year, or even between one year and anotherSupply depends on the capacity of withdrawing technique.Methods of tapping water from water sourcesBy making use of gravityBy using a pump

Haripur dam

RiversSources of irrigation water all over the world.The flow of river fluctuates over time.The discharge of rivers is commonly expressed in cubic meters per second.Tapping water from riversDirect river diversionRiver diversion using a weirPumping from a river

Hub dam

LakesNatural depressions of land.Lakes are supplied with water byrainfall that falls directly on the surface of lakes.By water run-off from adjacent land.Lakes loses water via Evaporation.Through percolation from the bottom of the lake to the groundwater.The amount of irrigation water required must be less than the quantity of water available in lakes

The Jhelum

ReservoirsAmount of water in a reservoir depends onRiver discharge Height of the damArea of the reservoirOn-stream storageOff-stream storage

Pumping from a Lake or ReservoirWater can be taken from lakes or reservoir viaDirect diversionConcrete or steel pipePumps Indus river from

Karakouram highway

GroundwaterAn important source of irrigation waterGroundwater may be found close to the surface or at profound depthIn coastal plains the groundwater is often brackish or saline due to the proximity of the seaInland groundwater may also be brackish in places where the soil contains many soluble saltsPumping from wellsTo tap groundwater a well must be dig deeper than the groundwater level.Shallow groundwaterDeep groundwater

Kabul attock

Surface water of Pakistan

The Ravi

DamsBefore Partition:

Khushdil Khan Dam (1890).Spin Karaiz (1945).Namal Dam (1913).

After Partition:Mangla Dam.Tarbela Dam.

Mangla dam

RiversWater Sources measurement at Rim Station.Rim StationIndus RiversBrings 154 MAF of Water annually (144.91 MAF from Western Rivers and 9.14 MAF from Eastern River).104.73 MAF used for irrigation.39.4 MAF flows to sea.9.9 MAF is consumed by the system losses.

s Sutlej river

It comprises of Major reservoirs : 3Barrages : 16Head Works : 2Siphons : 2 Inter river link canals : 12Canal system : 44 •Punjab : 23•Sindh : 14•NWFP : 5•Balochistan : 2Watercourses : 107,000Aggregate length of canals is about 56,073 km.Watercourses, Form Channels and Field Ditches, covers 1.6 million km.Tube wells : 500,000 The chanab

Ground Water Sindh and Balochistan : 40 ft depth.Rachna Doab : 100 ft .1950’s SCARP introduced deep tube wells to control salinity and water logging. Within 30 years 13,500 tube wells were installed (9300 in Punjab).Now about 41.6 MAF water supply is from 500,000 tube wells . In Punjab 79%, in Sindh 28% of the area is underline by freshwater.Ground water become a major supplement of canal supplies in last 25-30 years. Tarbela spillway

Quality of ground water.Fresh (salinity less than 1000 mg / l TDS).Saline (salinity less than 3000 mg / l TDS). Punjab79% fresh water.9.78 million acres are underline with ground water of less than 1000 mg/ l TDS.3 million acres with salinity ranging from 1000-3000 mg / l TDS. 3.26 million acres with salinity more than 3000 mg / l TDS.Saline water in central Doab area.Brackish water in Cholistan area.Ground water with high fluoride contents in Kasur, Mianwali and Bhawalpur

Rawal dam

Sindh28 % fresh groundwater.Found at depth of 20-25 m.Large area with groundwater of poor quality.Thar, Nara and Kohistan with non-portable, highly brackish water.Tharparker and Umerkot with high fluoride contents in ground water.

NWFPIn NWFP, certain areas such as Karak, Kohat , Bannu and D.I. khan has lowered the water table and resulted in contamination.

BalochistanMakran coastal zone with highly brackish groundwater.Local communities use groundwater with TDS as high as 3000 mg / l for drinking purposes. Mastung Valley, Makran Coast and Kharan with high flouride contents in groundwater. Lahore canal

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