Groundwater is among the most valuable water resources in the entire world,
especially in arid and semiarid regions (Todd and Mays 2005; Mukherjee et al.
2012). It is commonly considered as the best quality water for drinking and irrigation
everywhere (Hoque et al. 2009; Adiat et al. 2012). Besides these domestic, agricultural, and industrial uses, the in situ functions of groundwater are also significant:
feeding the flow of springs and streams, as well as maintaining the stability of the
land surface and preventing the migration of saline water or other poor-quality water
into fresh aquifer domains (Gun and Lipponen 2010). Groundwater has several
advantages such as consistent temperature, wide availability, decentralized access,
limited vulnerability, outstanding natural quality, low extraction cost, and drought
protection capacity (Jha et al. 2007; Arkoprovo et al. 2012). Another quality of
groundwater in comparison to surface water is that it is the least affected by
disastrous events and can be tapped when required (Manap et al. 2013). Consequently, exploitation of groundwater as the alternative to the insufficiency and
irregularity of surface water is ever increasing (Manap et al. 2013).
Groundwater has a significant function in fulfilling the water requirements of the
agriculture, industrial, and domestic sectors in India. About 85% of India’s rural
domestic water requirements, 50% of its urban water needs, and more than 60% of
its irrigation requirements are being met from groundwater resources (Mall et al.
2006; Chinnaiah 2015; CGWB 2019a). Hence, India has become the world’s largest
consumer of groundwater by extracting 248.69 BCM (billion cubic meters) groundwater annually, one fourth of the total global annual groundwater extraction, about
90% (221.46 BCM) of which is used in irrigation (CGWB 2019a). In 1995, net
groundwater draft from irrigation uses was about 115 BCM, which indicates almost
doubling of groundwater extraction within a time span of 15 years (CGWB 2011).
Although groundwater-based irrigation accounts for about 60% of the total irrigated
area of India, 80% of the country’s total agricultural production is still dependent on
groundwater in one form or another (Dains and Pawar 1987; Wani et al. 2009). Also,
crop productivity in groundwater-irrigated areas is higher (often double) in comparison to that in surface water-based irrigated areas (Shah 1993; Meinzen-Dick 1996;
Wani et al. 2009). So, groundwater extraction in the irrigation sector has been
accelerated significantly in India, mainly controlled through decentralized private
activity rather than under strict government policy. Hence, the groundwater
resources of the country are now facing crisis, urgently requiring attention and
understanding of the situation (Gandhi and Bhamoriya 2011).
According to the United Nations Convention Framework on Climate Change, “a
change of climate which is attributed directly or indirectly to human activity that
alters the composition of the global atmosphere and which is in addition to natural
climate variability observed over comparable time periods” (UNFCC 1992; Karl
et al. 2009; Anupam and Shinjiro 2013). Climate change leads to changes in
precipitation and evapotranspiration rates, which have a deep impact on the hydrological cycle, resulting in large-scale modifications in the amount and status of water
present in glaciers, rivers, lakes, and oceans (Panwar and Chakrapani 2013). Such
changes will influence subsurface hydrological dynamics and cause changes in
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S. Mukhopadhyay and A. K. Mandal
especially in arid and semiarid regions (Todd and Mays 2005; Mukherjee et al.
2012). It is commonly considered as the best quality water for drinking and irrigation
everywhere (Hoque et al. 2009; Adiat et al. 2012). Besides these domestic, agricultural, and industrial uses, the in situ functions of groundwater are also significant:
feeding the flow of springs and streams, as well as maintaining the stability of the
land surface and preventing the migration of saline water or other poor-quality water
into fresh aquifer domains (Gun and Lipponen 2010). Groundwater has several
advantages such as consistent temperature, wide availability, decentralized access,
limited vulnerability, outstanding natural quality, low extraction cost, and drought
protection capacity (Jha et al. 2007; Arkoprovo et al. 2012). Another quality of
groundwater in comparison to surface water is that it is the least affected by
disastrous events and can be tapped when required (Manap et al. 2013). Consequently, exploitation of groundwater as the alternative to the insufficiency and
irregularity of surface water is ever increasing (Manap et al. 2013).
Groundwater has a significant function in fulfilling the water requirements of the
agriculture, industrial, and domestic sectors in India. About 85% of India’s rural
domestic water requirements, 50% of its urban water needs, and more than 60% of
its irrigation requirements are being met from groundwater resources (Mall et al.
2006; Chinnaiah 2015; CGWB 2019a). Hence, India has become the world’s largest
consumer of groundwater by extracting 248.69 BCM (billion cubic meters) groundwater annually, one fourth of the total global annual groundwater extraction, about
90% (221.46 BCM) of which is used in irrigation (CGWB 2019a). In 1995, net
groundwater draft from irrigation uses was about 115 BCM, which indicates almost
doubling of groundwater extraction within a time span of 15 years (CGWB 2011).
Although groundwater-based irrigation accounts for about 60% of the total irrigated
area of India, 80% of the country’s total agricultural production is still dependent on
groundwater in one form or another (Dains and Pawar 1987; Wani et al. 2009). Also,
crop productivity in groundwater-irrigated areas is higher (often double) in comparison to that in surface water-based irrigated areas (Shah 1993; Meinzen-Dick 1996;
Wani et al. 2009). So, groundwater extraction in the irrigation sector has been
accelerated significantly in India, mainly controlled through decentralized private
activity rather than under strict government policy. Hence, the groundwater
resources of the country are now facing crisis, urgently requiring attention and
understanding of the situation (Gandhi and Bhamoriya 2011).
According to the United Nations Convention Framework on Climate Change, “a
change of climate which is attributed directly or indirectly to human activity that
alters the composition of the global atmosphere and which is in addition to natural
climate variability observed over comparable time periods” (UNFCC 1992; Karl
et al. 2009; Anupam and Shinjiro 2013). Climate change leads to changes in
precipitation and evapotranspiration rates, which have a deep impact on the hydrological cycle, resulting in large-scale modifications in the amount and status of water
present in glaciers, rivers, lakes, and oceans (Panwar and Chakrapani 2013). Such
changes will influence subsurface hydrological dynamics and cause changes in
126
S. Mukhopadhyay and A. K. Mandal