GCSE Geography | Case Study: Indus River Basin (Resource Management - Food 6)

The Indus River flows through Pakistan to the Arabian Sea - it has a huge river basin covering around 1 million km2, including parts of India and China. The river is fed by heavy rain and snowmelt and is a really important source of water for both India and Pakistan, providing plenty of water for irrigation in the drier land further south. As a result the Indus Water Treaty was signed in 1960 to give India control of the eastern rivers within the basin, and Pakistan the Indus itself and the western tributaries.

What is the Indus River Basin System (IBIS)?

The IBIS is a huge irrigation system - the largest continuous system in the world. It was initially built when this area was part of the British Empire and started off as a series of irrigation canals, but has been expanded over time. There are now three large dams and more than a hundred small dams that control the flow of the water, with 3 huge reservoirs behind the main dams, including the Tarbela Dam (pictured below) and reservoir which can hold 11 billion cubic metres of water. Water is transferred between rivers through 12 major link canals. In addition, there are 64,000 km of minor canals distributing water across the countryside, and more than 1.6 million km of streams and ditches that are used to irrigate farmland in Pakistan.

The IBIS was constructed for a number of reasons. Firstly, the region is pretty arid with low and unreliable rainfall, which cannot meet the demands of local food production. Before the IBIS food security was an issue due to the rapidly growing population, whereas now food can be grown on a large scale, so there is less need to import foods from other countries. Secondly, the IBIS has also helped with economic development, by increasing farm productivity through irrigation, and using the dams to generate hydroelectric power (HEP), to provide the energy needed to develop industries. This has enabled Pakistan to become a NEE. Finally, the IBIS is important for water management as the dams regulate the flow of water, reducing the risk of flooding, which has been an issue along the Indus River; and reservoirs store water when there is a plentiful supply following snow melt or monsoon rains, to use at times when supply is low.

Benefits of the Indus River Basin System

• It has increased the amount of land available for agriculture by 40%, which means food security has increased significantly - the system irrigates over 14 million hectares of land
• Food supply has been boosted with a huge increase in crop yields - wheat yields have increased by 36%, rice by 39% and fruit by 150%
• People in this region now have access to a wider variety of nutritious foods so their diets and health have vastly improved, including the increased availability of fish which are farmed in storage reservoirs (good for protein)
• Farming has increased export revenue with cash crops grown
• The IBIS provides many job opportunities, including increased jobs in farming, but also in HEP generation
• HEP provides green energy to use in industries that will aid Pakistan's economic development
• Water management reduces the risk of flooding and increases the ability to store water, which aids climate change resilience

Drawbacks of the Indus River Basin System

• Some farmers upstream take more than their fair share, which leads to over-abstraction, reducing the amount of water available downstream, affecting food production there
• Evaporation due to the intense heat in the summer leads to high levels of water loss
• Poor irrigation techniques leads to water wastage, as well as waterlogging and salinity, which both cause long-term damage to the soil, reducing fertility
• The reservoirs, barrages and canals all need constant maintenance - this is very expensive
• The IBIS depends on snow melt and the monsoon rains - climate change in the future may affect these reducing the water available
• Displacement of local communities - the dams will have flooded large valleys which means the loss of homes and farmland for many people
• Dams disrupt the natural flow of rivers and lead to sedimentation, as well as interrupting fish migration
• Dams also affect the depth of water, with the reservoir being much deeper than the original river, meaning the water is much colder, which could affect the marine habitat with animals unable to adapt to the change in temperature, which could lower biodiversity