ArticlePDF Available

Reducing carbon emissions through improved irrigation management: A case study from Pakistan

Authors:

Abstract and Figures

Increasing use of groundwater for irrigation is linked to high energy demand, depleting resources and resulting in a high carbon footprint. This paper explores how improved on-farm irrigation management can help in reducing groundwater extraction, limiting energy consumption and CO2 emissions. In Pakistan, every year about 50 billion cubic metres (BCM) of groundwater is pumped for irrigation, which consumes more than 6 billion kWh of electricity and 3.5 billion litres of diesel. Carbon emissions attributed to this energy use amount to 3.8 million metric tons (MMT) of CO2 per year. Considerable research carried out in Pakistan has suggested that improved irrigation management can significantly reduce the irrigation water applied to different crops. This study revealed that by adopting improved irrigation schedules, water productivity will increase and groundwater withdrawals for irrigation can be reduced by 24 BCM. Reduced groundwater extraction will result in a 62% decline in energy demand (1.5 billion litres of diesel as most of the private tubewells run on diesel) and a 40% reduction in carbon emissions. In addition, a reduction in irrigation applications will also be beneficial for stabilizing groundwater tables and groundwater quality. Copyright (c) 2013 John Wiley & Sons, Ltd.
Content may be subject to copyright.
REDUCING CARBON EMISSIONS THROUGH IMPROVED IRRIGATION
MANAGEMENT: A CASE STUDY FROM PAKISTAN
ASAD SARWAR QURESHI*
Senior Environment Specialist, National Development Consultants (NDC), Lahore, Pakistan
ABSTRACT
Increasing use of groundwater for irrigation is linked to high energy demand, depleting resources and resulting in a high carbon
footprint. This paper explores how improved on-farm irrigation management can help in reducing groundwater extraction, limiting
energy consumption and CO
2
emissions. In Pakistan, every year about 50 billion cubic metres (BCM) of groundwater is pumped for
irrigation, which consumes more than 6 billion kWh of electricity and 3.5 billion litres of diesel. Carbon emissions attributed to this
energy use amount to 3.8 million metric tons (MMT) of CO
2
per year. Considerable research carried out in Pakistan has suggested
that improved irrigation management can signicantly reduce the irrigation water applied to different crops. This study revealed that
by adopting improved irrigation schedules, water productivity will increase and groundwater withdrawals for irrigation can be
reduced by 24 BCM. Reduced groundwater extraction will result in a 62% decline in energy demand (1.5 billion litres of diesel as
most of the private tubewells run on diesel) and a 40% reduction in carbon emissions. In addition, a reduction in irrigation applications
will also be benecial for stabilizing groundwater tables and groundwater quality. Copyright © 2013 John Wiley & Sons, Ltd.
key words: climate change mitigation; CO
2
emissions; groundwaterenergy nexus; groundwater table; Pakistan; agricultural practices; water management
Received 29 June 2012; Revised 7 June 2013; Accepted 7 June 2013
RÉSUMÉ
Laugmentation de lutilisation des eaux souterraines pour lirrigation induit une forte demande dénergie, épuise la ressource et
élève lempreinte carbone. Cet article explore comment lamélioration de la gestion de lirrigation à la ferme peut aider à réduire
lextraction deau souterraine, la consommation dénergie et les émissions de CO
2
. Au Pakistan, chaque annéeenviron 50 milliards
de mètres cubes (BCM) deau souterraine sont pompés pour lirrigation, qui consomme plus de 6 milliards de kWh délectricité et
3,5 milliards de litres de diesel. Les émissions de carbone attribuables à cette consommation dénergie sont 3,8 millions de tonnes
métriques (MMT) de CO
2
par an. Le travail de recherche considérable accompli au Pakistan a suggéré que lamélioration de la
gestion de lirrigation peut réduire considérablement leau dirrigation appliquée aux cultures. Cette étude a révélé quen améliorant
la programmation des horaires dirrigation, la productivité de leau va augmenter et les prélèvements deau souterraine pourront
être réduits de 24 BCM. Lextraction de leau souterraine se traduira par une réduction de 62 % baisse de la demande dénergie
(1,5 milliard de litres de diesel, la plupart des forages privés fonctionnant au diesel) et réduction de 40 % des émissions de carbone.
En outre, la réduction des applications dirrigation sera également bénéque à la stabilisation de la nappe phréatique et la qualité des
eaux souterraines. Copyright © 2013 John Wiley & Sons, Ltd.
mots clés: atténuation du changement climatique; émissions de CO
2
; nexus eau souterraineénergie; Pakistan; pratiques agricoles; gestion de leau
INTRODUCTION
Groundwater has emerged as an exceptionally important wa-
ter resource, and growing demand for its use in agriculture,
domestic and industrial contexts grades it as a resource of
strategic importance. In view of the high evapotranspiration
and salinity environment under which irrigated agriculture in
the Indus basin is practised, the availability of surface water
resources is only marginally sufcient for basin-wide, year-
round high-intensity cropping (Bhutta and Smedema, 2007;
Qureshi et al., 2009). This difference between crop water
requirements and surface water supplies, combined with gen-
erally unreliable and relatively inefcient water distribution
*Correspondence to: Dr Asad Sarwar Qureshi, Senior Environment Spe-
cialist (USAID Master Planning Project), National Development Consul-
tants (NDC), Lahore, Pakistan. E-mail: Sarwar65@yahoo.com
Réduire les émissions de carbone grâce à une meilleure gestion de
lirrigation: une étude de cas du Pakistan.
IRRIGATION AND DRAINAGE
Irrig. and Drain. (2013)
Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ird.1795
Copyright © 2013 John Wiley & Sons, Ltd.
systems, has led to the exploitation of groundwater where
conditions allow (World Bank, 2007; Qureshi et al., 2009).
The increasing role of groundwater in agriculture has
made it very energy-intensive. Groundwater exploitation
has enabled farmers to supplement their irrigation require-
ments and to cope with the vagaries of the surface supplies.
This allows them not only to increase their production level
and incomes but also enhance their opportunities to diver-
sify their income base and to reduce their vulnerability to
the seasonality of agricultural production, and to external
shocks such as droughts (Bhutta, 2002; Qureshi et al.,
2009). Groundwater use has also increased resilience to
climate change because surface storages have fared poorly
on these counts. These benets will become even more
important as climate change heightens hydrological variabil-
ity. From societys point of view, aquifer storage is also
advantageous because it minimizes water loss through non-
benecial evaporation for semi-arid countries like Pakistan,
where surface storages can lose 3 m or more of their storage
every year through pan evaporation (Shah, 2009).
The introduction of cheap technologies has played a key
role in the groundwater boom in Pakistan. As a result, farmers
tend to over-irrigate and a considerable amount of pumped
water evaporates, or goes back to the aquifer through deep
percolation. In both ways, a signicant amount of consumed
energy does not contribute to biomass production (Karimi
et al., 2012). Other disadvantages of excessive groundwater
use are declining groundwater tables and increasing salt
content in the pumped groundwater. Groundwater irri-
gation is also expensive as compared to gravity-run canal
irrigation. Furthermore, groundwater irrigation is also
considered an environmental hazard because the energy
used in pumping groundwater directly contributes to CO
2
discharge (Shah, 2009).
Pakistan is one of the lowest carbon emitters in the world
but the increasing use of groundwater for irrigation is put-
ting extra pressure on energy resources and directly contrib-
utes to an increase in CO
2
discharge. Therefore, productive
and efcient use of groundwater at farms and decreasing
pumping is benecial for stabilizing aquifers and reducing
carbon emissions, which could be a key climate change
adaptation strategy. This paper estimates the CO
2
emissions
as a result of groundwater extraction and quanties reduc-
tions in energy consumption and CO
2
emissions through
the adoption of improved irrigation management strategies.
OVERVIEW OF GROUNDWATER IRRIGATION
IN PAKISTAN
Groundwater evolution in Pakistan
The use of groundwater for irrigated agriculture in Pakistan
has a long history. Before 1960s, groundwater extraction
was carried out by means of open wells with rope and bucket,
Persian wheels, karezes, reciprocating pumps and hand
pumps. Large-scale extraction and use of groundwater for irri-
gated agriculture in the Indus basin started during the 1960s
with the launching of Salinity Control and Reclamation
Projects (SCARPs). Under this public sector programme, 16
700 wells (supplying an area of 2.6 million ha) with an
average capacity of 80 l s
1
were installed to control ground-
water and salinity problems (Bhutta and Smedema, 2007).
The demonstration of SCARP tubewells was followed by
an explosive development of private tubewells with an
average discharge capacity of about 28l s
1
. The provision
of subsidized electricity by the government and the intro-
duction of locally made diesel engines provided an impetus
for a dramatic increase in the number of private tubewells.
Currently, about 1.2 million small-capacity private tubewells
are in operation in Pakistan (Qureshi et al., 2008). Out of
these, 800 000 are located in Punjab (Figure 1). Investments
in the installation of private tubewells are of the order of US
$400 million whereas the annual benets in the form of
agricultural production are to the tuneof US$2.5 billion (Shah
et al., 2003). The estimated number of users is over 2.5 million
farmers, who exploit groundwater directly or hire the services
of tubewells from their neighbours. Groundwater currently
provides more than 50% of the total crop water requirements,
with exibility of availability on an as and when needed basis
(Shah, 2007).
Patterns and benets of groundwater use
In Pakistan, about 70% of the private tubewells are located
in the canal command areas where groundwater is used in
combination with the canal water, whereas the rest provide
irrigation based on groundwater alone. The combined use
of surface water and groundwater (usually referred as
conjunctive use) is now practised on more than 70% of the
irrigated lands in Pakistan. The area irrigated by groundwater
alone has increased from 2.7 to 3.4 million ha, whereas the
Figure 1. Development of private tubewells in the Punjab Province (Data
source: Punjab Irrigation Department)
A. S. QURESHI
Copyright © 2013 John Wiley & Sons, Ltd. Irrig. and Drain. (2013)
area irrigated by canal water alone has decreased from 7.9 to
6.9 million ha (Qureshi et al., 2004). In Pakistan large-scale
production of major crops such as wheat, cotton, rice and
sugar cane is only possible because of the supplemental use
of groundwater for irrigation. The average cost of irrigating
with groundwater is 30 times higher than that of surface irr-
igation (World Bank, 2007). The cost of canal water per year
per hectare is US$5.5, whereas groundwater is marketed as
US$67 ha
1
yr
1
.
The benets of groundwater in Pakistan are multi-
dimensional and range from drinking water supplies for the
urban and rural population, to economic development as a
result of higher agricultural production. The role groundwater
irrigation has attained in maintaining the agricultural boom is
unique and vital and will expand further in future due to
mounting pressure to grow more food and increasing inci-
dences of drought in the region. Qureshi et al. (2003) have
shown that more than 70% of the farmers in the Punjab
depend directly or indirectly on groundwater to meet their
crop demands. Therefore management of this resource
requires high level of attention and commitment both from
government agencies and from agricultural and domestic users.
Sustainability of groundwater resources
The unregulated and uncontrolled use of groundwater has
diminished its relative accessibility. The trend of continuous
decline of the groundwater table has been observed in many
areas of the Indus basin, which illustrates the serious imbal-
ance between abstraction and recharge. Figure 2 shows the
changes in groundwater table depths over a period of
10 years (19932003) in the Punjab province. As a result,
many wells have gone out of production, yet the water tables
continue to decline and the quality deteriorates. Excessive
exploitation of aquifers in fresh groundwater areas has
resulted in falling water tables and groundwater has become
inaccessible in 5 and 15% of the irrigated areas of Punjab
and Balochistan provinces, respectively. Although no recent
estimates exist, it was estimated that under the business as
usual scenario, this area is expected to increase to 15% in
Punjab and 20% in Balochistan by 2020 (Punjab Private
Sector Groundwater Development Project (PPSGDP),
2000). The variation between different canal commands is
mainly linked to groundwater quality. In relatively fresh
groundwater areas, extraction is greater because farmers
there tend to grow water-intensive crops such as rice and
sugar cane. In poor-quality groundwater areas, extraction
is low in order to avoid secondary soil salinization.
Energy use for groundwater extraction in Pakistan
In Pakistan, the use of electricity for groundwater pumping
started in the 1970s, when the rural electricity grid was
expanded and the government provided much-needed incen-
tives for farmers to install tubewells to boost agricultural
production. In 1980s, the tubewell population surged from
37 000 to 84 000, making it difcult for the government to
collect revenue through the metering system (Qureshi and
Akhtar, 2003). Increased electricity prices and unannounced
power cuts resulted in the stagnation of electric tubewells
and an increase in diesel tubewells. Although the cost of
water from diesel tubewells (2.20 US¢ m
3
) was still
Figure 2. Increase in area with a groundwater table depth of 300 cm over a period of 10years (19932003) in different canal commands of the Punjab and Sindh
provinces (Source: Qureshi et al., 2009)
REDUCING CARBON EMISSIONS THROUGH IMPROVED IRRIGATION MANAGEMENT
Copyright © 2013 John Wiley & Sons, Ltd. Irrig. and Drain. (2013)
higher than electric tubewells (0.70 US¢ m
3
), diesel
tubewells were preferred due to low initial installation and
operational costs.
The latest estimates suggest that in 2010, farmers
extracted 50 billion cubic metres (BCM) of groundwater
through 1.2 million diesel and electric tubewells (Qureshi
et al., 2010). Of this, about 0.8 million are located in Punjab.
About 200 000 tubewells are operated by electric motors
whereas the remaining 1 million are run by diesel engines
of various capacities.
1
Out of a total 50 BCM of ground-
water extraction, about 12 BCM is extracted using electric
pumps and the remaining 38 BCM using diesel pumps.
The depth to groundwater is directly linked to energy
requirements for water extraction. In a countrywide survey
of 1200 private tubewells, Qureshi et al. (2003) found that
in Pakistan, electric tubewells are used to extract water from
greater depths (4080 m) and diesel tubewells are used for
shallow water table areas (6.015 m). The farmers use
pumps which are not energy-efcient due to low capital
investment. Due to high friction losses in wells and inef-
cient water conveyance systems, energy losses are very
high. Energy requirements for extracting groundwater are
highly sensitive to the dynamic head over which the ground-
water is lifted. Therefore for energy calculations for this
paper, a conservative estimate of dynamic head for electric
and diesel pumps has been taken. For electric tubewells, a
dynamic head of 60 m is assumed. For diesel pumps, a
dynamic head of 1015 m is considered because beyond this
depth diesel pumps become extremely inefcient, forcing
irrigators to switch to electricity. Therefore for diesel
pumps, operational hours are more important for energy
requirement calculations than dynamic head.
Electricity consumption in groundwater irrigation can be
calculated based on the energy requirement to lift the water.
To lift 1000 m
3
water from 1-m depth at 100% efciency
(without considering friction losses), 2.73 kWh of energy
are required (Karimi et al., 2012). Thus energy consumption
can be calculated as follows:
Ec ¼2:73 DV=OPE 1TlðÞ1000 (1)
where
Ec = electricity consumption (kWh)
D= lifting height (m)
V= volume (m
3
)
OPE = overall pumping efciency, and
Tl = transmission and distribution losses (only in the
case of electric pumps; otherwise zero).
The average overall pumping plant efciency
2
(OPE) of
electric pumps in Pakistan is about 40% (Buksh et al.,
2000). Electricity transmission and distribution losses are
usually taken as 25% (Water and Power Development
Authority (WAPDA), 2009). Therefore, electricity that is
actually used to lift 1000 m
3
of water from 1 m depth is 9.1
kWh. If we consider an average dynamic head of 60 m, then
lifting 12 BCM of groundwater would require 6.0 billion
kWh of electricity. This estimate is highly sensitive to the
assumption about the dynamic head over which a representa-
tive electric pump lifts water.
Diesel-powered tubewells are even less efcient but
they lift water to a smaller head; moreover, diesel does
not face the transmission and distribution losses that
electricity suffers and a litre of diesel provides the equiv-
alent of 10 kWh of energy. Diesel tubewells are usually
installed in shallow groundwater table areas (6.015 m).
The fuel consumption of diesel engines (Chinese and slow
speed diesel engines) is 1.52.5 l h
-1
whereas tractor-operated
tubewells burn 3.55.0 l h
-1
(Qureshi et al., 2003). The utiliza-
tion factor of private diesel tubewells is between 10 and 15%
(1350 h yr
1
). Therefore total annual fuel consumption of 1
million diesel tubewells (assuming 2.5 l h
-1
and 1350 h yr
1
)
would be 3.5 billion litres. Therefore total energy consump-
tion for groundwater extraction amounts to 41 billion kWh.
Taking into account the consumption of 6 billion kWh elec-
tricity and 3.5 billion litres of diesel, it can be calculated that
on average extracting 1m
3
groundwater requires 0.820 kWh
of energy in Pakistan. This amount of energy is equivalent
to lighting up a 100 W bulb for more than 8 h.
Carbon footprints of Pakistans groundwater irrigation
Pakistans contribution to total global greenhouse gas (GHG)
emissions is miniscule (about 0.8%) and its per capita GHG
emissions stand at a level which corresponds to one-third of
the global average (Planning Commission, 2010). The total
GHG emissions of Pakistan in 1994 were 182 MMT of CO
2
equivalence, which increased to 309 MMT of CO
2
equivalence
in 2008, registering an increase of 3.9% yr
1
(Pakistan Atomic
Energy Commission, 2009). The biggest contributor to GHG is
the energy sector with 51% share, followed by the agriculture
sector (39%), industrial processes (6%) and other activities
(5%). Future estimates suggest that due to increasing energy de-
mand, CO
2
emissions from the energy sector will increase to
2685 MMT of CO
2
equivalence from the current level of only
157 MMT of CO
2
equivalence. This shows the importance for
Pakistan that it take serious steps to control GHG emissions in
the energy sector. Controlling groundwater extraction could be
one of the most effective strategies in this direction.
Carbon intensity of electricity and diesel is 0.4062 kg C
kWh
-1
and 0.732 kg C l
-1
, respectively (Shah, 2009). This
implies that annually a total sum of 3.8 MMT of CO
2
is
emitted as a result of groundwater irrigation in Pakistan. Of
this gure, which is roughly 1.2% of Pakistans total carbon
emissions, 1.4 MMT of CO
2
is emitted through electricity
consumption and 2.4 MMT of CO
2
through diesel
A. S. QURESHI
Copyright © 2013 John Wiley & Sons, Ltd. Irrig. and Drain. (2013)
combustion. In other words, on average, the extraction of ev-
ery cubic metre of groundwater in Pakistan comes with a hid-
den environmental cost of 80 g of carbon emissions. Therefore
controlling energy demand in the agriculture sector would be a
big step forward in limiting overall carbon emissions.
POTENTIAL FOR REDUCING CO
2
THROUGH
IMPROVED IRRIGATION MANAGEMENT
There are different potential ways of reducing energy use in
agriculture. The rst option is to improve energy efciency
by increasing overall pumping plant efciency through the
use of high-quality pumps and electric motors. However,
such interventions are expensive and, more importantly,
have limited scope. The second option is to introduce on-site
renewable energy sources such as wind and solar energy.
These sources will neither lead to transmission and distribu-
tion losses, like electric energy, nor will they produce CO
2
emissions, like diesel tubewells. The initial investments in
these resources might be high; however, considering their
long-term economic and environmental benets they should
be given serious consideration. The third option is to reduce
irrigation water demand through improved on-farm water
management practices. This option is particularly relevant
to Pakistan where on-farm water use efciencies are
extremely low. Average crop yields of major crops are low
in Pakistan, for example: 2770 and 3190 kg ha
-1
for wheat
and rice, respectively. There is great variability in crop
yields with some farmers achieving 5500 kg ha
-1
of wheat
and 3545 kg ha
-1
of rice (Qureshi et al., 2004). The produc-
tivity of water in Pakistan is among the lowest in the world.
For wheat, for example, it is 0.6 kg m
-3
as compared to
1.0 kg m
-3
in India. Maize yields in Pakistan (0.4 kg m
-3
)
are nine times lower than those in Argentina (2.7 kg m
-3
)
(Bastiaanssen, 2000). This reveals substantial potential for
increasing water productivity.
Irrigation practices in Pakistan and options
for improvement
Despite the shortage of water, over-irrigation is a major
problem in Pakistan. The impact of this is not only wastage
of water, which could be used by other sectors or used in
expansion of agriculture, but also waterlogging and soil
salinity problems. This means that a signicant amount of
the applied irrigation water is lost by seepage from the
irrigation canals and deep percolation in the elds (Bhutta
and Smedema, 2007). Even though much of this lost water
is now captured by extensive groundwater pumping and
used downstream, this does not apply to the saline
groundwater zone. From a basin perspective, improvements
in farm irrigation efciency may result in little gain in
saving water except for those areas where groundwater is
saline (Clemmens and Allen, 2005). Nevertheless, reducing
water delivery to farms and improving farm water use
efciency are important from the perspective of other con-
siderations like reducing energy consumption, costs and
improving production (Karimi et al., 2012).
Farmerscurrent irrigation practices in Pakistan are aimed
at applying the maximum amount of water in an attempt to
maximize their crop yields. Farmers having access to
groundwater in addition to canal water tend to apply more
water compared to those who are fully dependent on canal
water. Due to uncertainties in canal water supplies, farmers
usually do not plan their irrigations in advance. Their
decision to irrigate mainly depends upon the crop water need
and availability of water in the canal system and/or access to
groundwater. The water requirements of different crops
depend upon environmental conditions, soil types and other
factors that are equal across all the farms. However, different
studies have shown that the number of irrigations applied to
a wheat crop varies from 4 to 7, to cotton from 4 to 8, and to
rice from 16 to 25 (Vlotman et al., 1994; Raza and Choudhry,
1998). The depth of individual irrigation applications has been
the subject of many research studies. Vehmeyer (1992) found
that it ranged from 60 to 90mm. Vlotman and Latif (1993)
determined the average depth applied per irrigation at between
70 and 80mm. On the basis of eld measurements, Raza and
Choudhry (1998) reached a value of 6090 mm with an aver-
age of about 85 mm per irrigation. If, on average, 6 irrigations
to wheat and cotton and 20 irrigations to rice crop are consid-
ered with an amount of 80 mm per irrigation, irrigation water
applied to wheat and cotton will be equal to 480mm whereas
for rice it will be 1600 mm. The average irrigation application
in the Indus basin is 36% (Ahmad, 2009).
Considering the water scarcity in the Indus basin, many
researchers have tried to nd optimal irrigation schedules
for different crops. The modelling work of Qureshi and
Bastiaanssen (2001) has suggested that applying 300 mm
of water to wheat and cotton (instead of the current practice
of 420 mm) is enough to produce optimal crop yields with-
out increasing salinity levels in the soil. This saving can be
achieved by reducing amounts of individual irrigations.
Based on their eld experiments, Choudhary and Qureshi
(1991) have also shown that improved irrigation manage-
ment techniques such as furrow-bed and furrow-ridge can
reduce irrigation requirements by 40%. They have
recommended an irrigation application of 260300 mm for
wheat and cotton crops to achieve optimal yields.
Prathapar and Qureshi (1999) used the SoilWater
AtmospherePlant (SWAP) model (Van Dam et al., 1997)
to simulate optimal irrigation schedules for wheat and cotton
crops. They found that irrigation applications can be reduced
to 80% of the total crop evapotranspiration (ET) without
compromising on yields and soil salinization, and recom-
mended 300320 mm as the optimal irrigation amount for
REDUCING CARBON EMISSIONS THROUGH IMPROVED IRRIGATION MANAGEMENT
Copyright © 2013 John Wiley & Sons, Ltd. Irrig. and Drain. (2013)
wheat and cotton crops. Similarly improved irrigation
methods for rice such as direct seeding also reduce irrigation
amounts by 1520% (Qureshi et al., 2006). The amount of
water applied to rice was 1200mm as compared to the
1870 mm usually applied under traditional planting. High
efciency irrigation methods such as drip and sprinkler
systems have also proved successful in increasing water use
efciency. However, in a country like Pakistan where contin-
uous availability of water and energy are big issues, adoption
of these technologies will remain a challenge, especially for
small farmers (Qureshi et al., 2010). For this reason, on-farm
water conservation techniques which are less costly and
energy intensive should be encouraged more.
To summarize the results of the above studies, these
results suggest that 300 mm of irrigation water for wheat
and cotton and 1300 mm for the rice crop is sufcient to
produce optimal yields under the existing soil and climatic
conditions of the Indus basin. Table I compares the irriga-
tion amounts, total water use and water savings for current
and optimized irrigation practices.
Table I clearly shows that adoption of the above-
mentioned irrigation practices for wheat, cotton and rice
can save up to 24 BCM of water, which is about 14% of
the total renewable water available in the Indus basin.
Applying these improved irrigation techniques to other crops
can further reduce the water demand for irrigation and stress
on groundwater. Under the current surface-water-scarce
conditions of the Indus basin, this water is contributed through
groundwater extraction, as is evident from the declining
groundwater table conditions in most of the canal commands
(Figure 2). Farmers with access to groundwater tend to apply
more irrigation water than those farmers fully relying on
surface water (Shah et al., 2003). Reducing groundwater
extraction by 24 BCM will reduce diesel consumption by
2.2 billion litres (62%) and CO
2
emissions by about 40%
(1.5 MMT of CO
2
). With these reductions, total consumption
of diesel will be reduced to 1.3 billion litres and CO
2
emis-
sions to 2.3 MMT of CO
2
. These calculations have been made
assuming an irrigation application efciency of 65%. Under
the furrow irrigation method (the most widely practised in
the Indus basin) irrigation efciency ranged between 65 and
95% with an attainable level of 85% (United States Depart-
ment of Agriculture (USDA)). Therefore greater water savings
can be achieved by implementing optimized irrigation sched-
ules together with advanced farm levelling, application rate
control, and other management options.
The above analysis demonstrates that the adoption of
improved irrigation practices will not only help in
reducing energy consumption and CO
2
emissions but will
be a big step forward in stabilizing aquifers. Adoption of
these improved practices requires a shift in the thinking
of farmers from maximizing crop productionwith
increased irrigation supplies to optimize crop produc-
tionwith minimum irrigation supplies. Such a change
in farmersmentality could be facilitated by measures
such as revising the existing energy pricing system. For
instance, removing or limiting the subsidies on electricity
could help to reduce groundwater over-pumping and
encourage more efcient use of water.
CONCLUSIONS
Groundwater use in agriculture has increased signicantly in
the past few decades and it has become a lifeline to
Pakistans agricultural production. Currently, it provides
more than 50% of the total water available at the farm gate
and in many areas is the sole water resource for summer
crops. However, rapidly dropping groundwater water tables
in aquifers all over the country indicate that the extraction
rate is far greater than the real capacity of these resources.
Under these circumstances, groundwater availability
might decrease considerably in future, which will have
serious consequences for the food security of this country.
On the other hand, groundwater use is also linked with a high
energy demand and carbon footprint in Pakistan. In
Pakistan, the extraction of 50 BCM of groundwater consumes
30 billion kWh of energy. Carbon emissions attributed to this
energy use are 3.8 MMT of CO
2
yr
1
. Therefore reducing
irrigation water demand through improved irrigation
practices is vital for preserving the environment and sustaining
groundwater resources.
Table I. Comparison of total water use and water savings under current and improved irrigation practices (Data source: Punjab Agriculture
Department)
Crop Area (ha)
Current irrigation practices Improved irrigation practices
Total water
saving (BCM)
Irrigation (mm) Total water use (BCM) Irrigation (mm) Total water use (BCM)
Wheat 8 578 000 480 41.2 300 25.7 15.5
Cotton 3 100 000 480 14.9 300 9.4 5.5
Rice 1 016 000 1 600 16.3 1 300 13.3 3.0
Total 72.4 48.4 24.0
A. S. QURESHI
Copyright © 2013 John Wiley & Sons, Ltd. Irrig. and Drain. (2013)
Despite the fact that pumping is an energy-intensive
activity, so far very little attention has been given to the
carbon footprint of groundwater irrigation in Pakistan. This
study shows that adoption of improved irrigation practices
will save up to 24 BCM of irrigation water, which in turn, will
reduce the energy demand and carbon emissions by 40%. This
shows that enhancing water productivity through improved ir-
rigation management can help in coping with water, energy,
and climate change issues in Pakistans agricultural sector.
ENDNOTES
1
Mostly privately owned diesel tubewells are powered by
1024 hp engines. These engines are of two types, i.e. the
1216 hp Chinese engines known locally as Petter
enginesand 2024 hp slow speed engines known locally
as the Black (Kala) engine.
2
OPE is the product of power plant efciency (engine,
alternator, etc.), shaft efciency and pump efciency.
REFERENCES
Ahmad S. 2009. Water availability and future water requirements. Paper
presented at the National Seminar on Water Conservation, Present Situation
and Future Strategy. Ministry of Water and Power, Islamabad, Pakistan. May.
Bhutta MN. 2002. Sustainable management of groundwater in the Indus
basin. Paper presented at the Second South Asia Water Forum, 1416
December. Pakistan Water Partnership: Islamabad, Pakistan.
Bhutta MN, Smedema LK. 2007. One hundred years of waterlogging and
salinity control in the Indus valley, Pakistan: a historical review. Irriga-
tion and Drainage 56: 581590.
Bastiaanssen WGM. 2000. Water issues for 2025: a research perspective.
Research contribution to the World Water Vision report. Colombo, Sri
Lanka: International Water Management Institute.
Buksh D, Ijaz H, Ahmad S, Yasin M. 2000. EMz ceramics for improving
fuel efciency of diesel pump sets in Pakistan. Journal of Nature
Farming and Environment 1(2): 915.
Choudhary MR, Qureshi AS. 1991. Irrigation techniques to improve the application
efciency and crop yield. Journal of Drainage and Reclamation 3(1): 1418.
Clemmens AJ, Allen RG. 2005. Impact of agricultural water conservation
on water availability. In Proceedings of the EWRI World Water and
Environmental Resources Congress,2005:Impacts of Global Climate
Change,1519 May, Anchorage, Alaska, USA; 14 pp.
Karimi P, Qureshi AS, Bahramlo R, Model D. 2012. Reducing carbon
emissions through improved irrigation and groundwater management: a
case study from Iran. Agricultural Water Management 108(2012): 5260.
Pakistan Atomic Energy Commission. 2009. Greenhouse gas emission
inventory of Pakistan for 200708. (Internal report to be published.)
Punjab Private Sector Groundwater Development Project (PPSGDP). 2000.
Legal and Regulatory Framework for Punjab Province. Technical Report
No. 45. Lahore, Pakistan.
Prathapar SA, Qureshi AS. 1999. Modeling the effects of decit irrigation
on soil salinity, depth to watertable and transpiration in semi-arid zones
with monsoon rains. International Journal of Water Resources Develop-
ment 15(1/2): 141159.
Qureshi AS, Bastiaanssen WG. 2001. Long-term effects of irrigation
water conservation on crop production and environment in semi-
arid zones. ASCE Irrigation and Drainage Engineering 127(6):
331338.
Qureshi AS, Shah T, Akhtar M. 2003. The groundwater economy of
Pakistan. IWMI Working Paper No. 64. International Water Management
Institute, Colombo, Sri Lanka; 23 pp.
Qureshi AS, Akhtar M. 2003. Effect of electricity pricing policies on
groundwater management in Pakistan. Pakistan Journal of Water
Resources 7(2): 19.
Qureshi AS, Asghar MN, Ahmad S, Masih I. 2004. Sustaining crop produc-
tion under saline groundwater conditions: a case study from Pakistan.
Australian Journal of Agricultural Sciences 54(2): 421431.
Qureshi AS, Masih I, Turral H. 2006. Comparing water productivities of
transplanted and direct seeded rice for Pakistani Punjab. Journal of
Applied Irrigation Science 41(1): 4760.
Qureshi AS, McCornick PG, Qadir M, Aslam Z. 2008. Managing salinity
and waterlogging in the Indus Basin of Pakistan. Agricultural Water
Management 95:110.
Qureshi AS, McCornick PG, Sarwar S, Sharma BR. 2009. Challenges and
prospects for sustainable groundwater management in the Indus Basin,
Pakistan. Water Resources Management 24(8): 15511569.
Planning Commission. 2010. Final Report of the Task Force on Climate
Change. Government of Pakistan, Islamabad, Pakistan. 98 pp.
Raza ZI, Choudhry MR. 1998. Soil Salinity Trends under Farmers
Management in a Pipe Drainage Project. International Waterlogging
and Salinity Research Institute (IWASRI) Publication No. 189. Lahore,
Pakistan; 88 pp.
Shah T, Debroy A, Qureshi AS, Wang J. 2003. Sustaining Asias ground-
water boom: an overview of issues and evidence. Natural Resource
Forum 27: 130141.
Shah T. 2007. The groundwater economy of South-Asia: an assessment of
size, signicance and socio-ecological impacts. In Giordano M, Villholth
KG (eds). The Agricultural Groundwater Revolution: Opportunities and
Threat to Development. CABI Publications: United Kingdom; 736.
Shah T. 2009. Climate change and groundwater: opportunities for mitiga-
tion and adaptation. Environmental Research Letters 4(2009): 13.
United States Department of Agriculture (USDA). Irrigation efciency.
http://ddr.nal.usda.gov/bitstream/10113/4018/IND43939089.pdf.
Van Dam JC, Huygen J, Wesseling JG, Feddes RA, Kabat P, Van Walsum
PEV. 1997. Simulation of Transport Processes in the SoilWaterAir
Plant Environment. SWAP Users Manual. DLO-Winand Staring Centre:
Wageningen, the Netherlands.
Vehmeyer P. 1992. Irrigation Management Strategies at the Farm
Level in a Warabandi Schedule. IWASRI Publication No. 122.
International Waterlogging and Salinity Research Institute: Lahore,
Pakistan; 127 pp.
Vlotman WF, Latif M. 1993. Present and Suggested Water Management
Strategies in Fixed Rotational Irrigation System at S1B9 of Fourth Drain-
age Project, Faisalabad. IWASRI Publication No. 148. International
Waterlogging and Salinity Research Institute: Lahore, Pakistan; 90 pp.
Vlotman WF, Beg A, Raza ZI. 1994. Warabandi, theory and farmers
practices at S1B9, Fourth Drainage Project, Faisalabad. Working paper,
IWASRI Publication No. 141. Lahore, Pakistan; 281 pp.
Water and Power Development Authority (WAPDA). 2009. Hydropower
Potential in Pakistan. Lahore, Pakistan. www.wapda.gov.pk
World Bank. 2007. Punjab Groundwater Policy––Mission Report.
WB-SA-PK-Punjab GW mission report, June 2007. www.worldbank.
org/gwmate.
REDUCING CARBON EMISSIONS THROUGH IMPROVED IRRIGATION MANAGEMENT
Copyright © 2013 John Wiley & Sons, Ltd. Irrig. and Drain. (2013)
... Likewise, India utilizes 18% its of total electricity and over 5% of the total diesel for irrigation purposes [9]. Nearly 6 billion kWh of electricity and 3.5 billion liters of diesel are used to operate irrigation pumps in Pakistan [10]. It is worth mentioning that around 1.6 billion people live without electricity in developing countries, and among them, approximately one billion people are from Sub-Saharan Africa and South Asia [11]. ...
Article
Full-text available
Insufficient rainfall in the dry season and scarcity of surface water has resulted in firms’ reliance on groundwater for agriculture in the northern part of Bangladesh. Most irrigation systems in the country are diesel or electric, which raises the cost and demand for energy and pollutes the environment. Utilizing the abundant sunshine and disseminating solar-based irrigation systems is expected to be a fittingly rewarding experience for irrigation purposes. Therefore, this study identifies the factors influencing the adoption of solar irrigation facilities (SIFs) and the impacts of their adoption on irrigation cost, return on investment (ROI), and production costs, using survey data collected from 405 rice farmers of Dinajpur district. The study employed three treatment effect estimators, namely inverse probability weighting (IPW), regression adjustment (RA), and inverse probability weighted regression adjustment (IPWRA), to address the potential selection bias issue. The results revealed that farming experience, knowledge, environmental awareness, soil fertility, and irrigation machinery ownership significantly influenced adoption decisions. The treatment effect model result indicated that farmers who adopted this method could minimize irrigation costs by 1.88 to 2.22%, obtain 4.48 to 8.16% higher ROI, and reduce total production cost by 0.06 to 0.98% compared to non-adopters. Our findings suggested that policy interventions targeting scaling up SIFs should consider focusing on government and stakeholders’ greater attention on designing more appropriate schemes through experimentation and multiple iterations.
... For the pressurized irrigation system, energy demand is estimated by multiplying the energy required to run the irrigation system (kWh year −1 ) and the energy price (US$ kWh −1 ), being either diesel or electricity. The energy consumption is estimated from Eq. (5) where TDH indicates the total head required to run the irrigation system, i.e., the operational head, friction losses, and suction lift. Labor costs are calculated by summing up the product of labor charges (US$ ha −1 ) and the harvested area (ha year −1 ). ...
Article
Full-text available
Pakistan’s agriculture is characterized by insecure water supply and poor irrigation practices. We investigate the economic and environmental feasibility of alternative improved irrigation technologies (IIT) by estimating the site-specific irrigation costs, groundwater anomalies, and CO2 emissions. IIT consider different energy sources including solar power in combination with changes in the irrigation method. The status quo irrigation costs are estimated to 1301 million US$ year⁻¹, its groundwater depletion to 6.3 mm year⁻¹ and CO2 emissions to 4.12 million t year⁻¹, of which 96% originate from energy consumption and 4% via bicarbonate extraction from groundwater. Irrigation costs of IIT increase with all energy sources compared to the status quo, which is mainly based on diesel engine. This is because of additional variable and fixed costs for system’s operation. Of these, subsidized electricity induces lowest costs for farmers with 63% extra costs followed by solar energy with 77%. However, groundwater depletion can even be reversed with 35% rise in groundwater levels via IIT. Solar powered irrigation can break down CO2 emissions by 81% whilst other energy sources boost emissions by up to 410%. Results suggest that there is an extremely opposing development between economic and ecological preferences, requiring stakeholders to negotiate viable trade-offs.
... In such a way, Gonzalez Perea et al. [73] achieved a 15% reduction in energy consumption by implementing more efficient irrigation and water management practices, with no significant yield reduction. Qureshi [74], improving on-farm irrigation management, achieved a 40% reduction in CO 2 emissions in Pakistan. Cvejic et al. [75] also reduced the irrigation-volume consumption by 25% and the GHG emissions by 24%, through the adoption of irrigation-decision support systems tools in Vipava Valley (Slovenia). ...
Article
Full-text available
Curbing greenhouse gas (GHG) emissions to combat climate change is a major global challenge. Although irrigated agriculture consumes considerable energy that generates GHG emissions, the biomass produced also represents an important CO2 sink, which can counterbalance the emissions. The source of the water supply considerably influences the irrigation energy consumption and, consequently, the resulting carbon footprint. This study evaluates the potential impact on the carbon footprint of partially and fully replacing the conventional supply from Tagus–Segura water transfer (TSWT) with desalinated seawater (DSW) in the irrigation districts of the Segura River basin (south-eastern Spain). The results provide evidence that the crop GHG emissions depend largely on the water source and, consequently, its carbon footprint. In this sense, in the hypothetical scenario of the TSWT being completely replaced with DSW, GHG emissions may increase by up to 50% and the carbon balance could be reduced by 41%. However, even in this unfavourable situation, irrigated agriculture in the study area could still act as a CO2 sink with a negative total and specific carbon balance of −707,276 t CO2/year and −8.10 t CO2/ha-year, respectively. This study provides significant policy implications for understanding the water–energy–food nexus in water-scarce regions.
... Furthermore, 70-80% of total pesticide production is used on the cotton crops (Bakhsh et al. 2017;Nazli and David Orden 2012); chemical-intensive farming practices lead to negative impact on land, on farmers' health, and pollute water resources and are the most important environmental impacts (Aktar et al. 2009;Bakhsh et al. 2016;Joko et al. 2017;Kouser and Qaim 2011;Makhdum et al. 2011;Watto and Mugera 2016a). Additionally, intensive use of these external inputs over the years has led to enhanced greenhouse gases emissions, CC, ultimately resulting in increasing the water and carbon footprints (Fabiani et al. 2020;Imran et al. 2018;Qureshi 2014). These inefficient management practices have created serious environmental, social, and economic problems in the cotton-cropping zone of Pakistan. ...
Article
Full-text available
Traditional agricultural practices, extensive use of inputs, and abrupt changes in climate have been of great concern to agriculture production around the world, especially in developing countries. Therefore, it is very vital to adopt and expand Climate-Smart agricultural (CSA) practices. By the cross-sectional data of 350 cotton farmers from major cotton-growing districts of Punjab Pakistan, adoption of CSA practices such as irrigation and soil and crop management practices is evaluated, and factors which affect farmer adoption decision and its impact on poverty, income, and yield are estimated by using logistic regression and propensity score matching (PSM) respectively. The results found that education, access to credit, tubewell ownership, farming experience, and access to extension services positively influenced farmers’ adoption behavior. Further, PSM results revealed that adoption of CSA practices is economical, financially, environmentally desirable, and pro-poor. According to these findings, ultimately adoption would help in reducing the negative impact of climate change on the cotton crop by ensuring profits, removing the barriers in the adoption, disseminating the information about CSA, and strictly enforcing the regulations for CSA.
Article
Full-text available
Study on survey, characterization and classification of groundwater quality in the different districts of Madhya Pradesh was undertaken with total 6483 samples from 51 districts. Out of total samples, 4379 ground water samples from 17 districts were collected by AICRP on Management of Salt Affected Soils and Use of Saline Water in Agriculture (SAS&USW), Indore while data of remaining 2104 ground water samples from 34 districts were acquired from CGWB, New Delhi. The ground water samples were analyzed in the laboratory for electrical conductivity (EC), pH, concentrations of cations (Na+, K+, Ca2+ and Mg2+) and anions (CO3 2-, HCO3 -, Cl- and SO4 2-). The water samples were categorized into different irrigation water classes as per criterion provided by Central Soil Salinity Research Institute, Karnal on basis of EC, SAR and RSC. The irrigation water classes include good quality, three subclasses for saline type and three subclasses for alkali type. The data clearly indicated that 87.3% samples were found in good water class “A”, 6.7% in marginally saline (B1), 0.8% in saline (B2) and only 0.2% in high SAR saline water class (B3), respectively. Among alkali water samples, 183 samples (2.8%) come under marginally alkali (C1), 109 samples (1.7%) in alkali water (C2) and 34 samples (0.5%) in high alkali water class (C3), respectively. Most of the ground water samples under good water class had dominance Ca followed by Na and then Mg. In case of anions, Cl was dominant ion followed by HCO3 and CO3. Further spatial maps were prepared for EC, pH, SAR and RSC of groundwater using GIS software (ArcMap GIS software 9.3.1). Intersection of spatial maps of EC, SAR and RSC was done to prepare spatial map indicting suitability of groundwater quality for irrigation purpose on basis of different irrigation water classes.
Article
Tillage methods and nitrogen (N) application are critical for soil organic carbon (SOC) sequestration and crop production. However, both tillage and N are the main contributors to the carbon footprint (CF) in agricultural production. A 6-year-long field experiment was conducted under a winter wheat-summer maize cropping system in Northern China to test how tillage methods (RT, annual rotary tillage; DT, annual deep tillage; and TT, RT applied annually with a DT interval of two years) and N rates (300 kg ha–1, N300; 225 kg ha–1, N225; 165 kg ha–1, N165) affect SOC sequestration, greenhouse gas (GHG) emissions, and annual grain yield. And, the CF was used to evaluate ecological sustainability. RT preferentially sequestrated SOC in the 0–10 cm soil layer. In the 10–30 cm soil layers, 2.87–3.82 and 1.85–2.53 Mg ha–1 greater SOC were respectively observed under DT and TT than RT, which was conducive to maximizing annual grain yield with less N application (N225) relative to traditional farming practice (RT-N300). Both increasing N rate and deep tillage resulted in obvious increases in the total GHG emissions. N fertilizer production and transportation were the greatest contributors, accounting for 40.4–47.0% of the total GHG emissions, followed by direct N2O and CH4 emissions (23.5–30.5%). TT-N225 significantly reduced CF (CF including SOC sequestration was 0.49 Mg CO2 eq ha–1 year–1 lower than DT-N225, and was 1.87 Mg CO2 eq ha–1 year–1 lower than RT-N300) and maintained high crop productivity while creating appropriate soil conditions and thus may be a much cleaner agricultural strategy in Northern China. And, the strategy of reducing N application in agricultural production by improving soil properties of the plow layer in this study can also be referred to in other ecological regions.
Article
A study was undertaken to monitor the impact of crop diversification and groundwater pumping efficiency on carbon-dioxide (CO2) emission in the three blocks of SAS Nagar/Mohali district in Punjab. The groundwater pumping for paddy crop was observed to be the main source of CO2 emission for all the blocks of SAS Nagar. The results recorded about 40% reduction in CO2 emission in Dera Bassi block with increase in the pump efficiency from 30% to 50%. Similar was the trend for other blocks (Kharar and Majri). After diversification of area under paddy crop with the other kharif crops, the CO2 emission was reduced by 21.38% in Dera Bassi. Whereas, the increasing area under paddy crop after crop diversification, as done in case of Kharar block has a negative impact on energy requirement and CO2 emission, where the total CO2 emission increased by 7.97%. Overall, diversification of area under paddy crop with a suitable kharif crop in conjunction with increased pumping efficiency from 30 to 50% may greatly help to reduce the CO2 emission resulting from groundwater irrigation.
Article
Full-text available
In arid environments, water shortages due to over-allocation of river flow are often compensated by lift irrigation or pumping groundwater. In such environments, farmers using pumped irrigation can deploy on-farm energy-efficient and water-saving technologies; however, pumping water requiring extra energy is associated with carbon emissions. This study explores how to increase crop production using pumped irrigation with minimal energy and carbon emissions. The purpose of this research is twofold: first, to examine on-farm energy consumption and carbon emissions in gravity and groundwater irrigation systems; and second, to explore system-level alternatives of power generation and water management for food production based on the results from the farm-level analysis. This study employs a novel system-level approach for addressing water, energy, and carbon tradeoffs under pumped irrigation using groundwater. These tradeoffs are assessed at farm and system levels. On-farm level estimates showed that farm-level interventions were insufficient to produce mutual gains. According to the results of the system-level evaluation, system-level interventions for water and energy conservation, the use of renewable energy to pump water for irrigation, and river basin scale cooperation are all required to maintain crop production while reducing energy consumption and carbon emissions.
Article
Climate change is a reality, and irrigated agriculture is a significant human activity that contributes to greenhouse gas (GHG) emissions and, therefore, to global warming. Traditionally, the carbon footprint associated with GHG emissions has been computed by fixed electrical energy transformation rates (kgCO2e kWh⁻¹). However, this transformation rate is not constant because it depends on a country's power generation mix, which combines of the energy sources supplying a country (coal, nuclear, wind, photovoltaic, hydraulic, natural gas, etc.). Fixed transformation rates have been traditionally employed to estimate the carbon footprint that derives from irrigated agricultural activity. Nevertheless, these fixed rates can be inaccurate for not considering variations over time. Thus, in this work, a new decision support system called Carbon_in_WaterDSS was developed in Python and applied to a real-world scenario to determine a dynamic and realistic energy transformation rate and to compute an accurate carbon footprint. Different time periods were considered according to irrigation stakeholders' water management criteria, crop water requirements, energy costs and pricing electricity tariff periods. The results show that the energy transformation rate and, therefore, the carbon footprint value vastly vary during the irrigation season and over for a day (from 0.066 kgCO2e kWh⁻¹ to 0.490 kgCO2e kWh⁻¹), unlike the values found in other works. This work also highlights how farmers choose the most economical energy periods to use conventional electricity. However, this hourly choice criterion is not the option that generates the lowest carbon footprint value in most analysed years.
Article
Full-text available
Soil is a world in itself and can be understood and deepened and its various characteristics only through the breadth of the horizon of human knowledge and soil is the product of multiple geographically and interrelated elements such as (air, water, rocks, biology, climate, terrain and time) The importance of this study to use an applied analytical methodology in Detecting, monitoring, analyzing and producing maps of the spatial variation of the geological manifestations represented by the physical and chemical properties of many mineral elements within the soil and their impact on the nature of the soil within the study area and the basic problem represented by the problem of salinity facing the soil in Iraq It is located within an area characterized by a dry climate, especially the area of the plain sedimentary plain low slope, Highlights the role of natural and human geographic factors and their impact on the spread of the problem of salinity in some governorates of Iraq and therefore its impact on agricultural land. The study shows that the cultivated areas suffer from severe salinization in many governorates, especially the central parts of them. Arable areas and thus low dunum productivity
Conference Paper
Full-text available
Water and energy are the prime needs of human beings living on the earth. The burning of fossil fuels for the production of electricity releases vast amount of greenhouse gas emissions into the atmosphere due to which global warming and sea level are on the rise and has eventually caused the human civilization to suffer. Water resources can be used for irrigation purpose and also be utilized to produce electricity in the form of hydropower. Though Pakistan is deficient in oil and gas but it has a vast potential of hydropower, coal, wind, and solar energy resources. It is estimated that Pakistan has hydropower potential of about 60,000 MW but only 11% of it is utilized for the production of electricity and the remaining potential is still untapped. According to the data analyzed in this paper, the share of hydropower can become more than 40% and indigenous energy resources as a whole can contribute up to 80.7% in the supply mix for electricity production in Pakistan by the year 2030. At the same time the share of oil and gas which is currently more than 64% can be reduced to 11.8% percent which is favorable for the sustainable development of the country.
Article
Full-text available
In the Indus Basin of Pakistan, multi-strainer shallow tubewells often called 'skimming wells' are used to extract groundwater from thin fresh lenses underlain by saline groundwater. Most of these wells face problems such as deteriorating water quality and reduction in discharge due to inadequate design and poor operational and management strategies. This paper evaluates the current practices of farmers in the Chaj doab area of Pakistani Punjab and suggests improvements in design and operation of skimming wells to ensure long-term sustainability of irrigated agriculture in the area. The effect of existing design and operation of skimming wells on pumped groundwater quality was evaluated using MODFLOW. To study the long-term effects of skimmed groundwater use on crop production and soil salinity development, the soil water flow and solute transport model SWAP was applied. The results revealed that farmers could reduce the number of strainers from 16 to 6 without reducing the anticipated discharges. For the conditions considered, the maximum discharge of skimming wells should be 4–8 L/s and they should not be operated for more than 2–4 h per day. Increasing discharge rate or daily operational hours can disturb the interface between fresh and saline groundwater resulting in reduced quality pumped groundwater. Weekly operational schedules together with recommended discharge rate and operational hours will be the best strategy to use skimmed groundwater for achieving optimal crop yields while maintaining root-zone salinity within acceptable limits. To avoid aquifer degradation, skimming wells should be used for supplemental irrigation rather than full irrigation of crops. Due to low discharge rates, skimming wells cannot be used to irrigate crops through surface irrigation methods. Therefore, pressurised irrigation methods should be used. The results also suggest that continuation of present irrigation practices could lead to serious problems of land and aquifer degradation. Therefore, farmers need to adjust their irrigation and leaching requirements annually considering crop evapotranspiration, precipitation, and salinity status of soils.
Article
Full-text available
As water is becoming a scarcer commodity, savings in the irrigation sector could enhance water development in areas currently not being irrigated, and arrest the rapid environmental degradation due to waterlogging in and areas. The agro-hydrological model SWAP is used to investigate possible water reductions for wheat and cotton crops under shallow water table conditions prevailing in the Fourth Drainage Project in Punjab, Pakistan. The simulations are performed for both drained and undrained conditions considering three different irrigation water qualities. The overall objective is to save good-quality irrigation water. The results indicate that when good-quality canal water is available, a reduced application to wheat (195 mm) and cotton (260 mm) will keep the soil healthier under both drained and undrained conditions. For poor-quality irrigation waters (mixed canal and tubewell or tubewell alone), this water conservation strategy will be insufficient. Therefore, more water (325 mm for wheat and 325 mm for cotton) should be applied to keep crop production and soil salinity within desirable limits. However, this will only be applicable to the areas where proper subsurface drainage systems are present. For undrained areas, this strategy will not be feasible due to rising water tables; other options like growing more salt-tolerant crops should be considered. Drainage cannot solve salinity buildup problems under all circumstances because relatively dry monsoons provide insufficient leaching water, and salts added by tubewell irrigation can only be evacuated from the soil profile if the drainage system is very intense. Reduced irrigation inputs is a proper short-term solution, although wheat production tends to decline in all areas without drainage, even when irrigated with canal water. Large-scale drainage investments associated with adjusted irrigation planning seem unavoidable in the long run.
Article
Full-text available
2 ABSTRACT: In Pakistan over exploitation of groundwater for irrigation has emphasized the need to take immediate action to ensure sustainability of this precious resource. In recent decades the fortunes of groundwater and energy economies are closely linked. Little can be done in the groundwater economy that will not affect the energy economy. And the struggle to make the energy economy feasible is upset by often-violent opposition from farmers to cut down energy prices. As a result Pakistan's groundwater economy has boomed by bleeding the energy economy. This paper highlights the impacts of changing energy policies of the government on groundwater irrigation. In Pakistan there seem no practical means for direct management of groundwater, laws are unlikely to check the chaotic race to extract groundwater because of logistical problems of regulating a large number of small dispersed users, water pricing reforms tool will not work for the same reasons. Power supply and pricing policies offers a powerful toolkit for indirect management of both groundwater and energy use. However, using this tool effectively requires a blend of energy and water outlook which today is lacking. This paper also provides in-depth analysis of the tubewell owner's priorities for the Flat Tariff and the Flat-cum-Metered Tariff policies.
Article
Full-text available
A soil water and solute transport model, calibrated for a dominant soil series in the Punjab of Pakistan, was used to evaluate consequences of deficit irrigation in semi-arid areas with a shallow water table. Simulations were carried out to determine the influence of irrigation amounts and subsurface drainage conditions on root zone salinity, depth to water table and transpiration. Additional simulations were made to evaluate a range of irrigation practices adopted by farmers under field conditions. The simulation results show that provision of 80% of the cumulative evapotranspiration requirements as irrigation will result in acceptable limits of root zone salinity and depth to water table, without significantly affecting transpiration of wheat and cotton crops. Under such circumstances, subsurface drainage will not be necessary. Results also show that current irrigation practices in the Punjab are resulting in yield reductions in general, due to either water shortage or waterlogging.
Article
Full-text available
For millennia, India used surface storage and gravity flow to water crops. During the last 40 years, however, India has witnessed a decline in gravity-flow irrigation and the rise of a booming 'water-scavenging' irrigation economy through millions of small, private tubewells. For India, groundwater has become at once critical and threatened. Climate change will act as a force multiplier; it will enhance groundwater's criticality for drought-proofing agriculture and simultaneously multiply the threat to the resource. Groundwater pumping with electricity and diesel also accounts for an estimated 16–25 million mt of carbon emissions, 4–6% of India's total. From a climate change point of view, India's groundwater hotspots are western and peninsular India. These are critical for climate change mitigation as well as adaptation. To achieve both, India needs to make a transition from surface storage to 'managed aquifer storage' as the center pin of its water strategy with proactive demand- and supply-side management components. In doing this, India needs to learn intelligently from the experience of countries like Australia and the United States that have long experience in managed aquifer recharge.