Development of Water Resources

Q. Write a detail note on the uses of water

Uses of Water
The major uses of water are agricultural, domestic and industrial. The most important use
of water in Pakistan is for agriculture. At present 95% of water is used for irrigation
purposes.
Domestic Uses of Water
It includes:
1. Drinking
2. Cooking
3. Washing
4. Sanitation
Industrial Uses of Water
These are as follows:
1. It is used in Pharmaceutical industry for Injections and syrups.
2. In tanning industry for washing and Dyeing.
3. In food processing industry for preparing juices, squashes, syrups and Beverages
etc.
4. In chemical industry for making Acids, liquid bleach and solution etc.
5. In Textile industry for washing, bleaching, dyeing and printing,
6. In mineral water industry it is used.
7. In iron and steel industry to cool down the furnace for making steel etc.
8. In Thermal Power Stations to produce steam that make the turbine move.
Agricultural Uses of Water
In agriculture it is used for Irrigation. Irrigation is the artificial supply of water to the land
to encourage plant growth.
Q. Why we need Irrigation?
Most of the areas of Pakistan experience arid or semi-arid conditions, aridity increasing
from north to south. Rainfall is ineffective in many ways in Pakistan. For example, annual
rainfall is low(less than 250mm) in the whole of the Sindh, most of Balochistan except for
the high altitude areas, and a large part of Punjab. Spell of high temperature increases the

1
rate of evapo-transpiration. In most of the areas, especially in the south, the number of
rainy days is less than ten. Monsoon winds bring most of the rainfall but these are also
variable in timings. After the end of the rainy season there are long and frequent dry spells.
Such conditions demand a well developed irrigation system. Apart from canal irrigation
tube wells and some old traditional methods like Persian wheel, Charsa and Karez are also
used for irrigation.
Q. Explain some physical and human factors which help to extend the canal irrigation
in upper and lower Indus plain
These factors are as follows:
1. By canal irrigation we can save millions of gallons of water that would flow into
the Arabian Sea.
2. Cheap labour and availability of cement reduces the cost of canal construction.
3. It irrigates vast area even the deserts have been made productive.
4. Soft soil and level land of the Indus plain makes digging of canals easier than in the
rough land of Balochistan.
5. Southward slope of the river makes construction of canals easier, because water
flow southwards naturally.
6. Huge quantities of water from monsoon rainfall & melting of snow can be stored
in reservoirs during summer season.
Q. Explain some conventional system of Irrigation
Some conventional irrigation systems are as follows:
1- Shaduf: In the Shaduf system water is drawn from a well, river or canal by a bucket
which is attached to a pole on one side and weight on the other side. A small area
can be irrigated by this method.
2- Charsa: In Charsa, animal power is used to pull water from the well. It is not used
by many farmers now.
3- Persian Wheel: It is powered by blindfolded bullock. It turns a horizontal wooden
wheel geared to a vertical wheel at the distant end of the shaft. This carries the
vertical metal wheel in the left foreground, to which is attached a chain of earthware
pots. The pots raise water from the well and split their contents into the channel that
leads to the fields.

2
 4- Karez: A karez is a horizontal underground canal in the foothills that brings
underground water to the surface. It is practiced in Balochistan. Vertical shaft are
also dug so that it can be cleared and repaired to prevent any blockage in the flow
of water. Karez is dug by group of peoples.
5- Inundation Canals: Long canals taken off from large rivers are called inundation
canal. They receive water when the river is high enough and especially when it is
in flood. A diversion channel is a narrow version of an inundation canal.
6- Tank Irrigation: Tank irrigation is practiced by constructing mud banks across
small streams to make a small reservoir which collect excess water during the rainy
season.
Q. Write some disadvantages of conventional methods
Some disadvantages of conventional methods are as follows:
➢ Irrigated limited areas of land as only small amount of water can be obtained.
➢ Require manual labour or animals and are more time consuming.
➢ Are difficult to build, maintain and use (e.g. Karez ).
➢ Inundation canals only flow during rainy periods or when water from melting snow
and ice enters the rivers.
Q. Write some Modern Methods of Irrigation
Some Modern Methods of Irrigation are as follows:
➢ Perennial Canals: They are linked to dams and barrages to provide water
throughout the year and they irrigate a vast area.
➢ Tube wells: Tube wells have diesel or electrically operated pumps that can raise
water from the depth of 92 metres (300 feet) or more to irrigate farms of more than
1000 hectares. Tube wells also help to lower the water-table thereby protecting the
land from water logging and salinity.
➢ Sprinkler: Sprinkler or Spray Irrigation Sprinklers are connected to public water
supply pipes. They are centrally placed in fields to water the plants. They are used
mainly in orchards and market gardening.
➢ Tankers: Tankers collect water from the ponds and lakes and provide it to
households and fields in case of emergency. This method is very expensive and is
rarely used for irrigation.

3
Q. Write a detail note on Indus Water Treaty.
Ans. In 1947, with the creation of Pakistan, the province of Punjab was also divided into
East and West Punjab. The headworks of the canals of the Sutlej and Ravi remained in
India as the share of India while their drained areas became part of Pakistan. In 1948 India
threatened to stop the water supply from these headworks. That would have endangered
the prosperity of the Indus Plain. The water dispute was eventually resolved through the
help of the World Bank. In September 1960, an agreement was signed that is known as the
Indus Water Treaty. Under this treaty Pakistan received exclusive rights to the water of the
three western rivers (Indus, Jehlum and Chenab) and India to that of the eastern rivers
(Ravi, Beas and Sutlej). During the transitional period India agreed to supply water to
Pakistan till 1973. During the transitional period Pakistan was expected to construct two
storage dams, five barrages, one gated siphon and eight link canals. The construction cost
was to be met by Australia, Canada, USA, UK, West Germany and Newzealand. India was
also expected to pay some of the cost. The remaining expenditure was to be met by
Pakistan. WAPDA (Water and Power Development Authority) of Pakistan was entrusted
to supervise the projects. The following dams, barrages ands link canals have been
completed.
Dams
1. Mangla Dam
2. Tarbela Dam
Barrages
1. Chashma Barrage
2. Rasul Barrage
3. Marala Barrage
4. Qadirabad Barrage
Link Canals
1. Marala-Ravi
2. Rasul-Qadirabad
3. Qadirabad-Balloki
4. Balloki-Sulaimanki 1
5. Balloki-Sulaimanki 2

4
 6. Chashma-Jehlum
7. Trimmu-Sidhnai
8. Taunsa-Panjnad
Q. Write a short note on Mangla, Tarbela and Warsak Dam.
Ans.
Mangla Dam
The Mangla Dam is located on the river Jehlum. It is one of the longest earth-filled dams
in the world. It is designed to control and conserve the flood-waters of the Jehlum for
irrigation and to generate hydro-electric power.
Tarbela Dam
The Tarbela Dam is built on the Indus at Bara near the village of Tarbela. It is about thirty
km from the town of Attock. It is the world largest earth filled dam.
Warsak Dam
It is situated on the river Kabul near Peshawar.
Q. Differentiate between Small and Large Dams.
Ans.
Small Dams Large Dams
Store water for irrigation. Store water for irrigation.
Irrigates local areas only. Irrigates a vast area.
Supply water for Industrial and domestic use. Supply water for Industrial and domestic use.
Supply little or no electricity. Major suppliers of HEP.
Silting problem is easier to solve. Silting problem is difficult to solve.
Maintenance cost is low. Maintenance cost is high.
Less important for flood control. More important for flood control.

Q. Define Siltation and also write some causes, effects and control of Siltation.
Ans.
Siltation
It is the deposition of silt in the barrages and dams that can destroy the purpose of dams
and barrages i.e. irrigation and generation of HEP.

5
 Causes Effects Control
Abundance of silt eroded Blockage of canals because Large scale Afforestation
from the Karakoram, Hindu silt accumulated. especially on the foothills
Kush and Himalayan of Himalayas.
mountains.
Deforestation – ruthless Choking of irrigation Cement embankment of
cutting of trees for fuel and canals. canals to make cleaning
tiumber. easier.
Rivers from narrow and It also results in availability Installation of silt trap
deep valleys in the of less water for irrigation before the water flows to
mountainous areas. A purpose. the dams.
material is deposited into
the plains and piles up in
reservoirs of the dams.

Q. How you will differentiate Barrages from Dams.

Ans. Barrages in Pakistan are very long structures used for irrigation and flood control.
They do not involve the generation of electricity. The cost of construction of a barrage is
less than that of Dam. Unlike dams barrages can be made even in flat areas. There are
several barrages in Pakistan for e.g Marala barrage on River Chenab, Rasul barrage on
river Jehlum and Qadirabad barrage on river Chenab.
Q. Define Water-logging and Salinity.
Ans.
Water-logging and Salinity
The rise of the water table to the surface level is called water-logging and salinity is the
appearance of the salty patches is called salinity. Salty patches appears when water
evaporates from the surface of the earthy and leaves the salt behind.

6
Q. What is SCARP Project?
Ans. A detail plan was framed in 1959 to solve the problem of water-logging and salinity.
It divided the Indus Basin into 28 zones of reclamation. The program is called SCARP
(Salinity Control and Reclamation Project).
Q. Write some cures and preventions of Water-logging and Salinity.
Ans. Water-logging and salinity can be prevented and cure by the following methods.
1. Lining of canals to control seepage of water.
2. Canal closure on temporary basis so that water passes through only when needed
for irrigation purpose.
3. Installing tube wells to lower the water-table and to provide extra water to flush out
salts from the soil.
4. Planting eucalyptus tree.
5. Surface drain to divert surface water to nearby river or lake.
Q. Write a short note on surface water pollution.
Ans. Dumping of industrial and agriculture waste and inadequate sewage disposal systems
cause surface water pollution. In cities like Karachi, Lahore and Faisalabad the problems
are more severe than other areas. In Karachi oil seepage from ships is another cause of
water pollution. With increasing use of chemical and fertilizers agricultural waste is also
adding to the water pollution.
Q. How can we conserve and sustain the scarce water resources?
Ans. In order to conserve and sustain the scarce water resources, the following steps
should be taken.
• National priorities such as the maximisation of agricultural production should be
considered to the distribution of water between the provinces.
• Sites for small dams should be developed to store surplus flow during the monsoon
season.
• Canals should be lined to avoid water loss.
• Rivers and lakes should not be used as dumping sites of solid and liquid waste.
• Desalination of sea water to overcome the shortage of water.
• Natural fresh water lakes should be conserved to develop local water resources.
• Awareness should create among the people about the use of water.