Question

Which of the following is not an outcome of irrigation projects in India?
a)Increased salinisation of the soil
b)Groundwater depletion
c)Triggering floods due to loss of capacity in the reservoirs caused by sedimentation
d)All of these

Answer 1

Hint: Two thirds of India’s agriculture is dependent on monsoons. However monsoons are not a reliable source of irrigation and hence irrigation projects are commissioned. These irrigations comprise dams, bunds, canals and other such schemes

Complete answer: Depending on the area it serves, irrigation projects in India are divided into major, medium and minor irrigation projects.
Though irrigation projects help to increase productivity and yield, it has certain negative consequences too. Let us look at the options given to us:
Option (a)Increased salinisation of soil is an outcome of intensive irrigation as use of saline water, poor drainage and excessive irrigation leaves out salt in the soil. Irrigation salinity occurs as intensive irrigation causes leakage and groundwater recharge causing the water table to rise. Rising water tables can bring salts into the plant root zone and this affects both plant growth and soil structure. The salt remains behind in the soil when water is taken up by plants or lost to evaporation.
Option (b)Groundwater depletion is a negative consequence one has to face in areas of tubewell irrigation as tubewells draw water from the neighbouring areas and this leads to fall in level of the water table. Tube well irrigation and growing of water intensive crops lead to drying up land and groundwater resources.
Option (c)Triggering floods due to loss of capacity in the reservoirs caused by sedimentation is another consequence of irrigation projects.Reservoirs are often made for irrigation purposes. This to ensure that there is enough water stored for the drier seasons as well. However with time silt gets deposited in these reservoirs which leads to sedimentation of these reservoirs. Sedimentation eventually leads to the overflowing of the canal/river and flooding of the neighbouring areas.

Option (d) all of these above is therefore the correct answer.

Note: Water resources are used for both hydropower generation and irrigation. Multipurpose projects are those projects which serve many purposes like irrigation, power generation, flood control etc. Many irrigation projects are hence part of a multipurpose project. Examples of multipurpose projects include Bargi project in Madhya Pradesh, Bhima project in Maharashtra and Bhadra project in Karnataka.