An assessment of warabandi (irrigation rotation) in Pakistan: a preliminary analysis *.
Qureshi, Sarfraz Khan ; Hussain, Zakir ; Zeb-un-Nisa 等
I. INTRODUCTION
A significant feature of Pakistan's agriculture is that it is
served by the Indus irrigation system, which is one of the largest
contiguous irrigation systems in the world. The system comprises of the
Indus River and its tributaries, three major storage reservoirs, 19
barrages/headworks, 43 canals, and 12 link canals and 43 canals covering
about 43,000 chaks or village settlements. The total length of the canal
system is about 40,000 miles with over 80,000 water courses, field
channels and ditches running for another million miles. About 100-106
million acre feet (MAF) of surface irrigation supplies are diverted
annually into the canal system. Only 60 percent of this water reaches
the farmgate due mainly to low efficiency in the delivery of water. The
historical review of the area, production and yield trends shows that
agricultural production in the past has increased mainly due to
expansion in irrigated acreage while the contribution of changes in
yields has been insignificant. In general, agricultural production can
be increased by either expanding the irrigated cropped area or by
raising the crop yields. It is highly unlikely that Pakistan will be
able to satisfy the food needs of the rapidly increasing population
through yield increases alone. This means that there ia a need to
increase the irrigated cropped area through additional water supplies
and by improving the efficiency of water use through using the water
resources in a scientific manner.
The possibilities of increasing irrigated area by developing more
land and new surface water supplies in the short-run are limited as it
requires huge capital investments and strong political will. Resource
constraints and the imperative of maintaining macro-stability imply low
levels of public expenditure in the medium term. Until structural
reforms generate additional revenue, it is imprudent to finance
construction of additional storage facilities for surface water. The
political controversy relating to Kalabagh Dam is indicative of the
sensitive nature of building additional storage facilities for water in
Pakistan. Therefore, the only feasible option for increasing the
irrigated acreage is to provide additional water supplies through
improved management and efficient operation of various components of the
existing irrigation system.
That the Indus irrigation system is performing poorly is now
conventional wisdom. The efficiency of the canal system is low and
stands at about 40 percent from canal head to the root zone. Age,
over-use, poor operation and maintenance and defective management of the
irrigation system explain the deteriorating system efficiency. Two
recent studies of the irrigated agriculture World Bank (1993) and John
Mellor Associates (1993) have made a significant contribution to an
improved understanding of the problems facing the irrigation system. The
two studies just referred and other literature in Pakistan has
concentrated on evaluating the irrigation system upwards of the
watercourses and has only tangentially dealt with the issue of how far
farmers have been successful in the management of on-farm distribution
of water.
This paper makes a modest effort to rectify the past neglect of
research relating to on-farm use of irrigation water by focussing on an
analysis of the irrigation rotation system generally known as Warabandi.
In Section II, we describe the main features of the warabandi system.
The objectives set for the system have been culled out from the existing
literature for developing an index to evaluate the performance in a
quantitative manner. Section III presents the analytics of the
performance index for assessing the warabandi system. Section IV
presents the data and the findings. The last section highlights
important policy implications.
II. THE WARABANDI SYSTEM AND ITS OBJECTIVES
The warabandi system was developed during British Rule in the
Indo-Pak Subcontinent in the middle of the 19th century to manage the
irrigation system built by them. The system serves areas in Pakistan and
the slates of Punjab, Haryana, Rajisthan, and Western Uttar Paradesh in
India. The warabandi system has been explained by Malhotra (1982) and
Seckler (1980).
Warabandi means fixing of turns for irrigation water for each
farmer on a watercourse. There are two types of warabandi namely
"Kacha" and "Pucca". The Kacha warabandi is arranged
by the farmers themselves. Its rotation varies from 10 to 15 days
depending upon the number of farms on a given watercourse. In each chak
or village, a watch keeper used to announce to time for the benefit of
each farmer through drum beating. With the passage of time, most farmers
now own watches and can keep track of their turns and time. This system
of water rotation has many problems. Big farmers exploit the small
farmers and do not adhere to the agreed upon arrangement of water
supplies. This results in conflicts and farmers get involved in
time-consuming and expensive litigation. The large farmers do not care
for the irrigation needs of the small farmers. The tailenders are the
main losers.
To overcome this problem, on the request of any farmer who is not
satisfied with the system, the canal department regulates the supply of
water and fixes the turn of each farmer in a give crop year. This is
called Pucca warabandi. If any farmer violates this arrangement, he/she
is liable to prosecution under the Canal Act. The farmers who receive
water from the watercourse, in the area of what is called the
"Chak", are on a seven-day rotation schedule. Each farmer is
assigned what is called a proprietary right to a period of time e.g.
from 10.00 a.m. to 12.00 noon every week for which he is entitled to all
of the flow in the watercourse. (1) After every year the turn of each
farmer is rotated i.e. if farmer X has a turn in the day time, in the
next rotation his turn is shifted to night time. In this way, this
system of irrigation turns is operated without any serious problem of
equity as far as irrigating one's fields during the night are
concerned. The rotation's duration varies from one week to 10 days
at a given watercourse in different areas. In ease of canal closure, a
farmer missing a turn loses his water.
In Pakistan, the irrigation system is supply-oriented and
irrigation turns are not demand-oriented. The outlets from the
distributory are designed to discharge a fixed supply of irrigation
water whenever the distributory is running. Water keeps flowing through
these outlets whenever the distributory is operating. These outlets
(called "Moghas") are fixed open at a given discharge rate and
are built of concrete and steel to avoid tampering by farmers.
The objective of the warabandi system is to provide only that
amount of water which enables a farmer to irrigate one-third of his
cultivable command area (CCA) during all season. In the central Punjab,
"Pucca warabandi" is in vogue while in the southern Punjab and
Sindh "Kacha warabandi" is still practiced in some areas as a
majority of the big landlords reside in these areas and resort to
tampering of outlets and exploit small and tenant farmers. This type of
warabanch" suits the irrigation needs of large farmers.
Determination of Water Allocation
The method of water allocation reflects a peculiar feature of the
warabandi system. Officials of the irrigation department record the area
to be irrigated of each farmer in a chak. This area is called the
cultivable command area (CCA). The amount of time allocated to each
farmer is calculated on the basis of a water "duty" of one
cusec per 416 acres of CCA. The unique feature of this system is that
this duty is sufficient only to provide adequate irrigation to one-third
of each farmer's CCA in a normal weather year. On average, each
farmer can only irrigate about one-third of his area. This system of
water allocation in the Subcontinent was evolved to promote extensive
settlement of the region and to avoid famine. The objective behind such
a pattern of distribution for water was to irrigate the maximum area and
service as many farmers as possible. This policy meant paying a price in
terms of huge costs of constructing an extensive conveyance system and
water losses through seepage along the long conveyance route. In the
Indus Basin, 40 percent of water is lost through conveyance [Government
of Pakistan (1992)]. On the other hand this system encouraged the
efficient use of irrigation water as it had imposed scarcity on each
farmer and, by doing so, had increased the shadow price of water for
each farmer. Some critics have argued that warabandi is not cropping
pattern oriented and that it does not cater to the crop water
requirements especially for the high-yielding varieties (HYVs) of crops
[Reidinger (1980)]. Given the water allocation, each farmer is free to
choose the cropping pattern. Although this matter requires detailed
empirical study, one can argue that each farmer can optimise yields by
choosing the right level of crop intensity. This objection may not hold
as a majority of the farmers in Pakistan have managed to switch to
growing HYVs even without supplement of groundwater and yields in
"Pucca warabandi" areas have increased after the system was
adopted. For the past one decade or so the improvement of canals,
distributories and watercourse through remodelling and lining coupled
with precision land levelling has reduced the losses in the irrigation
system. Conveyance efficiency of the irrigation system has consequently
increased which has led to increased supply of water for farmers. In
this paper we use an indicator of water supply based on observation of
irrigated (wetted) area. The irrigated area comprised of farmer's
land that is wetted by irrigation water. In the warabandi system,
farmers rotate watering by fields, so that once the fields are measured,
it is easy to ascertain the area wetted by observation. Wetted area is a
rough indicator of irrigation water supplied. Its usefulness needs to be
estimated by empirical validation, In our analysis the net irrigated
area (NWA) is the area of land that is watered at least once in an
irrigation season and total irrigated area (TWA) is the NWA times the
frequency of irrigations that the area receives. Under the warabandi
system the predicted outputs are: (i) NWA is equal to 33 percent of CCA;
and (ii) TWA is equal to (0.33 x CCA x 4 =) 133 percent of CCA.
Measuring the actual NWA and TWA and comparing it with predicted levels
of irrigated areas allows us to determine whether the results of the
warabandi system are within the acceptable range or error. However the
indicators of NWA and TWA are subject to error due to ecology, soil
condition and irrigation practices.
III. THE ANALYTICAL FRAMEWORK
The assessment of the managerial efficiency of any management
system can be made by looking at the difference between the predicted
outputs of the system as specified by its objectives and the actual
results. If there is no difference between the two, the system is
operating with 100 percent efficiency. In a real world situation,
perfection is never obtained. In the previous section, we have shown
that the designers of the warabandi system had planned that each farmer
should be able to irrigate 1/3 of his CCA in each season. Allowing for
the four seasons, each farmer should be able to irrigate 133 percent of
his CCA during each crop year.
Comparing actual irrigated area with the designated irrigated
areas, one can get an idea about how well the system of warabandi has
been operating. The mean value of the difference between the actual and
the desired performance and coefficient of variations (CV) of the ratio
for the warabandi system can sometimes lead to contradictory results.
Mean value may be low and CV high or vice versa.
Theil's inequality coefficient (TIC) that treats positive
errors and negative errors of water supply equally and penalises large
errors more than small errors is a handy way of combining the mean error
and the uniformity error denoting dispersion. The index given by Theil
(1966) is as follows:
TIC = [square root of [summation] [(TWA - [TWA.sup.*]).sup.2]]
where
TWA = Actual total wetted area as defined in Section II.
[TWA.sup.*] = Predicted total wetted area as defined in Section II.
When TIC = 0, performance is perfect and when TIC = 100 percent, no
water is being delivered and performance is zero.
IV. SOURCES OF DATA AND FINDINGS
The data pertain to a water course randomly selected from the
Tandlianwala distributory in Faisalabad district. Thirty farmers were
selected at random to collect the needed data.
Information was collected for two crop seasons, namely, Rabi and
Kharif for the crop year 1992-93. Data were personally collected by one
of the authors. With this basic data, a preliminary view of the
warabandi performance of the chak in hand could be obtained. (2) As
pointed above, one objective of the warabandi is that NWA should be
equal to 33 percent of CCA. Table 1 shows that mean value of NWA/CCA
ratio is 30.64 percent (Rabi: 15.98 percent and Kharif: 14.65 percent)
with a coefficient of variation (CV) of 40 percent. The TWA provides the
comprehensive picture and its ratio (TWA/CCA) should be equal to 133
percent. The actual data show that the mean value of this ratio is about
104 percent with a CV of 66 percent with a seasonal break-up of 50
percent in the Rabi and 54 percent in the Kharif season. In the Rabi
season, water is short of crop requirement by about 35 percent and in
the Kharif the gap is 25 percent [Hussain and Rao (1991)]. In India
[Seckler (1980)] NWA/CCA and TWA/CCA ratios standing at 39 percent and
136 percent respectively. This means that the warabandi system is more
efficient in the Indian Punjab as compared to West Punjab (Pakistan).
The TWA is a better indicator of water supply than NWA which varies
with soil type and other conditions stated above. For this reason, we
use TWA in our analysis.
The objective function of the warabandi system with respect to TWA
is [TWA.sup.*], with [TWA.sup.*] = 1.33 x CCA for each farmer. This has
been calculated for each farmer and is reported in Table 1. For perfect
performance, the ratio of TWA/[TWA.sup.*] should be equal to 1.00 plus
or minus specified level of error. This ratio is 78 percent with CV of
66 percent showing a sub-optimal performance of the warabandi in
Pakistan. In India the ratio is close to one (102 percent) showing
relatively better performance than Pakistan.
The mean value and CV of the ratio (TWA/[TWA.sup.*]) raises the
issue of creating an index of managerial performance for any management
system. There are two kinds of error, firstly the mean error (ME) or the
difference between the mean of the objective function and the mean of
the actual performance which in this case is 22 percent (100-78) in the
TWA/TWA * ratio. This means that less water was delivered to the farmer
than specified in the objective function. The second is the uniformity
error (UE) or the dispersion of values around the mean. This is depicted
by the CV. The high value of UE may be attributed to management errors
or measurement error or exogenous factors. With these different kinds of
errors, it is difficult to judge the performance of the system in an
unambiguous way. Therefore, there is need to find an index which could
merge these two sources of errors to a single term. The concept of TIC
used in the previous section helps us to resolve the matter. The TIC for
Pakistan, reported in Table 1, is 037 for the crop year, 0.52 for Rabi
and 0.56 for Kharif seasons. The warabandi in tiffs chak is performing
at 63 percent effectiveness for the crop year, 48 percent for the Rabi
season and 44 percent for the Kharif season. It should be noted that in
the case of India, warabandi is performing at 80 percent effectiveness-a
level that is significantly higher than Pakistan.
A recent study completed at the International Food Policy Research
Institute (IFPRI) shows frequent water trading and selling/buying of
tubewell water in Pakistan. The tailenders often sell their water rights
to upstream farmers although it is legally prohibited. In this study it
is shown that water markets can be especially beneficial in expanding
conjunctive use of groundwater within the command canal irrigation
systems [Ruth (1993)]. The poor performance of warabandi found by us
clearly makes a case for water markets. It has been found that fellow
farmers do informal trading on a common watercourse. There is a
demonstrated need to re-look at the century's old warabandi system,
to make it more flexible, demand-driven and cropping pattern-oriented.
Farmers should be assigned proprietary rights to the water like land so
that they can freely trade water. This should increase the allocative
efficiency of irrigation water.
V. CONCLUSIONS AND POLICY IMPLICATIONS
The performance of the warabandi system has been evaluated on one
watercourse in Faisalabad district. Data from 30 formers were collected
regarding cultivable command area, net irrigated area and frequency of
irrigation in both seasons namely Rabi and Kharif. Ratios of net
irrigated area and total irrigated area to CCA were estimated. Theil
Index (TIC) was computed to evaluate the performance of the warabandi
system. The TWA/CCA ratios show that the system is working at 104
percent as against expected output of 133 percent. The TIC is computed
at 37 percent, which implies that the system is working at 63 percent
effectiveness. The comparison with an Indian study [Seckler (1980)]
shows that Pakistan's warabandi system is less effective than that
in the Indian Punjab.
The results of the study confirm the widely held belief that the
system of warabandi in the Indus Basin is not flexible enough to use the
vital water resource in an efficient manner. The institutional rigidity
of the system causes large conveyance losses and hampers the consumptive needs of the crops. Farmers tend to under-irrigate the fields which,
given other things, adversely affects the yields of crops. There is
ample evidence of surface water trading and water markets for
underground water. The system of warabandi needs to be modified to allow
water trading and development of water markets for surface water.
The farmers should be assigned proprietary rights to irrigation so
that they can use this precious resource where it has high marginal
productivity. The use of this resource be demand-led than supply-driven.
It should be priced at least at its marginal cost so as to generate
enough resources for the proper maintenance of the canal network. This
policy change will also encourage the conjunctive use of surface and
underground water. Results from the IFPRI study Ruth (1993) indicate
that use of groundwater in conjunction with canal irrigation increases
productivity.
Based on the consumptive needs of crops and stress function, the
duration of the warabandi may also be changed from present 7 days
rotation to 15 days rotation. Accordingly allocation of water to each
farmer during his turn should be increased. In this way net irrigated
area can be increased and crops will get water according to the
consumptive needs. This will also reduce the water losses that occur
during weekly rotations.
Appendix Table 1
Basic Data for Each Fanner Located on a Water Course in
District Faisalabad for 1992-93 Crop Year
S. No. NWA FREQ TWA
of CCA Rabi Rabi Rabi
Farmers (Acres) (Acres) (No.) (Acres)
1 12.00 2.00 4.00 8.00
2 12.50 3.00 4.00 12.00
3 12.00 2.50 3.50 8.75
4 25.00 4.50 4.50 20.25
5 12.00 3.00 3.50 10.50
6 12.00 2.25 3.50 7.88
7 12.00 1.50 3.00 4.50
8 12.00 1.50 3.00 4.50
9 2.00 0.50 0.45 0.23
10 4.00 1.00 1.30 1.30
11 12.00 2.00 4.45 8.90
12 6.00 0.50 1.30 0.65
13 6.00 0.50 1.30 0.65
14 6.00 0.50 1.30 0.65
15 25.00 3.00 6.00 18.00
16 25.00 3.25 6.00 19.50
17 25.00 3.00 5.30 15.90
18 12.00 1.50 2.75 4.13
19 12.00 1.50 2.75 4.13
20 25.00 2.50 6.00 15.00
21 6.25 0.75 1.50 1.13
22 6.25 0.75 1.50 1.13
23 6.25 0.75 1.50 1.13
24 6.25 0.75 1.50 1.13
25 6.25 1.50 2.25 3.38
26 6.25 1.50 2.25 3.38
27 12.50 2.50 4.50 11.25
28 12.50 2.50 4.50 11.25
29 12.50 2.00 4.00 8.00
30 8.00 1.25 3.00 3.75
S. No. NWA FREQ TWA NWA/
of Kharif Kharif Kharif CCA
Farmers (Acres) (No) (Acres) Rabi (%)
1 2.50 5.00 12.50 16.67
2 4.00 5.00 20.00 24.00
3 3.00 4.50 13.50 20.83
4 5.00 5.00 25.00 18.00
5 4.00 4.50 18.00 25.00
6 3.00 4.50 13.50 18.75
7 1.25 3.00 3.75 12.50
8 1.25 3.00 3.75 12.50
9 0.25 0.45 0.11 25.00
10 1.00 1.30 1.30 25.00
11 1.75 4.45 7.79 16.67
12 0.50 1.30 0.65 8.33
13 0.45 1.30 0.59 8.33
14 0.45 1.30 0.59 8.33
15 2.50 6.00 15.00 12.00
16 2.50 6.00 15.00 13.00
17 2.50 5.30 13.25 12.00
18 1.00 2.75 2.75 12.50
19 1.00 2.75 2.75 12.50
20 2.00 6.00 12.00 10.00
21 0.50 1.50 0.75 12.00
22 0.50 1.50 0.75 12.00
23 0.50 1.50 0.75 12.00
24 0.50 1.50 0.75 12.00
25 1.00 2.25 2.25 24.00
26 1.00 2.25 2.25 24.00
27 2.00 4.50 9.00 20.00
28 2.00 4.50 9.00 20.00
29 3.00 5.00 15.00 16.00
30 1.00 3.00 3.00 15.63
S. No. NWA/ NWA for TWA/ TWA/
of CCA Crop Year CCA CCA
Farmers Kharif (%) /CCA (%) Rabi (%) Kharif (%)
1 20.83 37.50 66.67 104.17
2 32.00 56.00 96.00 160.00
3 25.00 45.83 72.92 112.50
4 20.00 38.00 81.00 100.00
5 33.33 58.33 87.50 150.00
6 25.00 43.75 65.63 112.50
7 10.42 22.92 37.50 31.25
8 10.42 22.92 37.50 31.25
9 12.50 37.50 11.25 5.63
10 25.00 50.00 32.50 32.50
11 14.58 31.25 74.17 64.90
12 8.33 16.67 10.83 10.83
13 7.50 15.83 10.83 9.75
14 7.50 15.83 10.83 9.75
15 10.00 22.00 72.00 60.00
16 10.00 23.00 78.00 60.00
17 10.00 22.00 63.60 53.00
18 8.33 20.83 34.38 22.92
19 8.33 20.83 34.38 22.92
20 8.00 18.00 60.00 48.00
21 8.00 20.00 18.00 12.00
22 8.00 20.00 18.00 12.00
23 8.00 20.00 18.00 12.00
24 8.00 20.00 18.00 12.00
25 16.00 40.00 54.00 36.00
26 16.00 40.00 54.00 36.00
27 16.00 36.00 90.00 72.00
28 16.00 36.00 90.00 72.00
29 24.00 40.00 64.00 120.00
30 12.50 28.12 46.88 37.50
S. No. TWA for
of Crop Year
Farmers /CCA (%)
1 170.83
2 256.00
3 185.42
4 181.00
5 237.50
6 178.17
7 68.75
8 68.75
9 17.00
10 65.00
11 139.08
12 21.67
13 20.67
14 20.67
15 132.00
16 138.00
17 116.60
18 57.33
19 57.33
20 108.00
21 30.08
22 30.08
23 30.08
24 30.08
25 90.08
26 90.08
27 162.00
28 162.00
29 184.00
30 84.38
CCA: Cutivable Command Area; NWA: Net Wetted Area; TWA: Total Wetted
Area; FREQ Rabi. No. of irrigation in Rabi season; FREQ Kharif No.
of irrigation in Kharif season.
REFERENCES
Hussain, Z., and S. R. Rao (1991) Water Supply, Distribution and
Economic Value of Irrigation Water in the Indus Basin. Published in the
book entitled Agricultural Strategies in the 1990s: Issues and Policies.
Islamabad: Pakistan Association of Agricultural Social Scientists.
John Mellor Associates, Inc. (1993) Washington D. C. and Asianics
Agro-Dev. International (Pvt.) Ltd. Islamabad: Institutional Reforms to
Accelerate Irrigated Agriculture. Islamabad, Pangraphics.
Malhotra, S. P. (1982) The Warabandi System and its Infrastructure.
New Delhi: Central Board of Irrigation and Power.
Reidinger, Richard B. (1980) Water Management by Administration
Procedures in an Indian Irrigation System. In Walter E. Coward (ed)
Irrigation and Agricultural Development in Asia. Ethica and London:
Cornell University Press.
Ruth Meinzen-Dick (1993) Performance of Groundwater Markets in
Pakistan. The Pakistan Development Review 32:4 833-845.
Seckler, David (1980) The New Era of Irrigation Management in
India. New Delhi: Ford Foundation Working Paper. A Condensed Version
Published in the Journal of Indian Water Resources Society, 1985.
Thiel, Henri (1966) Applied Economic Forecasting. In Studies in
Mathematical and Managerial Economics. Vol 4. Amsterdam-Chicago:
North-Holland Publishing Company and Rand McNally & Company.
World Bank (1993) Irrigation and Drainage: Issues and Options.
Washington, D. C.: (World Bank Report No. 11884-Pak.)
Authors' Note: We are grateful to Dr Sohail J. Malik for
extensive comments on an earlier draft.
* Owing to unavoidable circumstances, the discussant's
comments on this paper have not been received.
(1) Under the Canal Act, the sale of water is prohibited. The
farmer has to use the allocated water on his farm.
(2) Generalisations of findings to the entire warabandi system of
Punjab province is hazardous. There can be large variations between
canal commands and between villages within each canal command. The
results should be treated as indicative. There is a need to do similar
studies for different commands.
Sarfraz Khan Qureshi is Joint Director, Pakistan Institute of
Development Economics, Islamabad, Zakir Hussain is an ex-Project
Officer, USAID, Islamabad and Zeb-un-Nisa is Staff Economist at the
Pakistan Institute of Development Economics, Islamabad.
Table 1
Descriptive Statistics and Performance Indicators for Warabandi on
one Selected Water Course in Pakistan and India
CCA NWA FREQ
(Acres) Rabi Rabi
(Acres) (No.)
PAKISTAN
Mean 11.75 1.81 3.15
STD 6.77 1.02 1.58
CV 0.58 0.56 0.50
TIC -- -- --
Fraction Error Due
to Basis
Fraction Error Due
to Difference
Variation
Fraction Error Due
to Difference
Covariation
INDIA
Mean
STD
CV
TIC
Fraction Error Due
to Basis
Fraction Error Due
to Difference
Variation
Fraction Error Due
to Difference
Covariation
TWA NWA FREQ
Rabi Kharif Kharif
(Acres) (Acres) (No.)
PAKISTAN
Mean 7.03 1.73 3.36
STD 6.11 1.25 1.72
CV 0.87 0.72 0.51
TIC -- -- --
Fraction Error Due
to Basis
Fraction Error Due
to Difference
Variation
Fraction Error Due
to Difference
Covariation
INDIA
Mean
STD
CV
TIC
Fraction Error Due
to Basis
Fraction Error Due
to Difference
Variation
Fraction Error Due
to Difference
Covariation
NWA/ NWA/
TWA CCA CCA
Kharif Rabi Kharif
(Acres) (%) (%)
PAKISTAN
Mean 7.51 15.98 14.65
STD 7.10 5.47 7.62
CV 0.95 0.34 0.52
TIC -- 0.54 0.60
Fraction Error Due
to Basis 0.57 0.67
Fraction Error Due
to Difference
Variation 0.67 0.13
Fraction Error Due
to Difference
Covariation 0.22 0.25
INDIA
Mean
STD
CV
TIC
Fraction Error Due
to Basis
Fraction Error Due
to Difference
Variation
Fraction Error Due
to Difference
Covariation
NWA for TWA/ TWA/
Crop CCA CCA
Year/CCA Rabi Kharif
(%) (%) (%)
PAKISTAN
Mean 30.64 50.28 54.11
STD 12.36 27.21 44.21
CV 0.40 0.55 0.82
TIC 0.35 0.52 0.56
Fraction Error Due
to Basis 0.05 0.83 0.63
Fraction Error Due
to Difference
Variation 0.00 0.09 0.04
Fraction Error Due
to Difference
Covariation 0.95 0.07 0.32
INDIA
Mean 38.75
STD 18.72
CV
TIC 0.48
Fraction Error Due 0.34
to Basis 0.06
Fraction Error Due
to Difference
Variation 0.12
Fraction Error Due
to Difference
Covariation 0.82
TWA for
Crop
Year/CCA
(%)
PAKISTAN
Mean 104.42
STD 69.27
CV 0.66
TIC 0.37
Fraction Error Due
to Basis 0.02
Fraction Error Due
to Difference
Variation 0.28
Fraction Error Due
to Difference
Covariation 0.70
INDIA
Mean 135.49
STD 45.70
CV 0.34
TIC 0.20
Fraction Error Due
to Basis 0.02
Fraction Error Due
to Difference
Variation 0.03
Fraction Error Due
to Difference
Covariation 0.94
CCA: Cultivable Command Area; NWA: Net Wetted Area; TWA: Total Wetted
Area; FREQ Rabi: No. of irrigation in Rabi season; FREQ Kharif No.
of irrigation in Kharif season.