IMPACTS OF CLIMATE CHANGE ON CROP WATER REQUIREMENT UNDER MULTI - REPRESENTATIVE CONCENTRATION PATHWAYS DURING MID-CENTURY: A CASE STUDY OF D. I. KHAN
Climate change is a major problem which directly affects agricultural economy of a region as the crop water
requirements of major crops is increased. This study was conducted to estimate evapotranspiration (ETo) and crop
water requirements (CWR) of wheat and maize crops of the study area during mid (2040-2059) century under emission
scenarios based on Representative Concentration Pathways (RCPs). The methodology employed here involves
the comparison of temperature and precipitation data projected by different GCM with the observed data. The delta
change and ratio method was used to obtain the corrected value of temperature and Precipitation (PPT) for the
future. The ETo calculator of Food and Agriculture Organization was used to calculate evapotranspiration. The CWR
of wheat and maize crops was computed using CROPWAT 8.0. Results showed that out of sixteen GCMs, only four
models i.e., bcc_csm1_1_m, gfdl_cm3, miroc5 and noresm1_m, were considered suitable for simulating the present
day climate for the study area. The Ensemble average of these four selected models showed an increase in mean
temperature of 2.07 oC and 2.47 oC, and an increase in PPT of 8% and 10% under RCP 4.5 and 8.5, respectively.
Similarly, ETo showed an increase of 17% and 21% under both scenarios. Ensemble seasonal CWR of wheat crop
under RCP 4.5 is projected to be increased by 10%, while under RCP 8.5 it increased by 8%. The CWR of maize
crop is projected to increase by 10% and 15% under RCP4.5 and RCP8.5, respectively.
(2013), “Climate change 2013: The Physical Science
Basis”, Contribution of working group 1 to the forth
Assessment Report of Intergovernmental Panel on
climate change. Cambridge University Press, UK.
2. Intergovernmental Panel on Climate Change (IPCC),
(2007a), “Climate change 2007: The Physical
science Basis” Contribution of working group 1 to
the forth Assessment Report of Intergovernmental
Panel on climate chang,. Cambridge University
3. Moss, R., Babiker, M., Brinkman, S., Calvo, E.,
Carter, T.R., Edmonds, J., Elgizouli, I., Emori,
S., Erda, L., Hibbard, K., Jones, R., Kainuma,
M., Kelleher, J., Lamarque,J-F., Manning, M.R.,
Matthews, B., Meehl, J., Meyer, L., Mitchell, J.F.B.,
Nakicenovic, N., O’Neill, B., Pichs, R., Riahi, K.,
Rose, S.K., Runci, P., Stouffer, R.J., van Vuuren,
D.P., Weyant, J.P., Wilbanks, T.J., van,Y.,persele,
J.P., Zurek, M., (2008), “Towards new scenarios
for analysis of emissions, climate change, impacts,
and response strategies”, IPCC Expert Meeting
Report, 19–21 September 2007. Noordwijkerhout,
The Netherlands, pp: 155.
4. Moss, R.H., Edmonds, J.A., Hibbard, K.A., Manning,
M.R., Rose, S.K., van Vuuren, D.P., Carter, T.R.,
Emori, S., Kainuma, M., Kram, T., Meehl, G.A.,
Mitchell, J.F.B., Nakicenovic, N., Riahi, K., Smith,
S.J., Stouffer, R.J, Thomson, A.M., Weyant, J.P.,
Wilbanks, T.J., (2010), “The next generation of scenarios
for climate change research and assessment”,
Nature, Vol.463(7282), pp: 747–756.
5. Van Vuuren, D.P., Edmonds, J., Kainuma, M.L.T.,
Riahi, K., Thomson, A., Matsui, T., Hurtt, G.,
Lamarque, J-F., Meinshausen, M., Smith, S., Grainer,
C., Rose, S., Hibbard, K.A., Nakicenovic, N., Krey,
V., Kram, T., (2011a), “Representative concentration
pathways: An overview”, Climatic Change.
6. Nakicenovic, N., Swart, R (eds) (2000), “IPCC
special report on emissions scenarios”, Cambridge
University Press, Cambridge
7. Taylor, K., Stouffer, R.J., Meehl, G.A., (2009),
“A summary of the CMIP5 Experiment Design”available online at (http://cmip-pcmdi.llnl.gov/
8. Iqbal.W., Zahid, M., (2014), “Historical and Future
trends of Summer mean air temperature over South
Asia”, Pakistan Journal of Meteorology, Vol.10,
Issue 20, pp: 67-74.
9. Khattak, M.S., (2011), “Impacts of climate change
on the water resources and irrigation water demand
in the upper Indus river basin, Pakistan”, Ph.D
Thesis, WEM, AIT, Thailand.
10. Ahmed, T., Scholz, M., Al-Faraj F., and Niaz W.,
(2016), “Water-Related Impacts of Climate Change
on Agriculture and Subsequently on Public Health:
A Review for Generalists with Particular Reference
to Pakistan”, International Journal of Environmental
Research and Public Health, Vol.13; pp1051
11. Marwat, S.K., Usman, K., Shah, R.A., Shah, A and
Khan, E.A., (2013), “Floristic account of Emergent-
Aquatic and Marshland Angiosperms of D.I. Khan
District, KPK, Pakistan”, Pak. J. Bot., Vol.45(SI),
12. Rahman, A., Khan,A.N. and Ali, Z., (2012),
“Evaluating Impacts of Chashma Right Bank
Irrigation project on the cropping intensity of District
D.I. Khan”, Journal of Managerial Sciences, Vol.6,
No. 1, PP: 93-112.
13. Marwat, S.K., Fazal-ur-Rehman., Usman, K.,
AbdurRasheed and Ghulam, S., (2012), “Biodiversity
of grassy weeds and their Ethnobotanical importance
in D.I. Khan, KPK”, Pakistan. Pak. J. Bot.,
Vol.44(2), pp: 733-738.
14. Khan, M., Khan, M.Q., Saifurrehman., Niamatullah,M.,
Sadiq,M., and Mian, I.A., (2011), “Characterization
of rhod kohi soil of D.I. Khan”, Pakistan, Sarhad
J. Agric., Vol.27, No.4.
15. Ashraf, A., Iqbal, M.B and Mustafa, N., (2009),
“Investigating potential artesian aquifers in Rod-
Kohi area of D.I. Khan, NWFP using GIS and
Geo-Processing Techniques”, Mehran University
Research Journal of Engineering and Technology,
Vol. 31, No. 3, pp: 361-370.
16. FAO (Food and Agriculture Organization), 2009.
CROPWAT Software, Food and Agriculture
Organization, Land and Water Division; Available
17. Allen, R.G., Pereira, L.S., Raes, D., Smith, M.,
(1998), “Crop evapotranspiration – guidelines for
computing crop water requirements” , FAO Irrigation
and Drainage Paper 56. ISBN 92-5-104219-5
18. Climate change knowledge portal 2.0 (http://
ThisCcode=PAK#ar5) access date March 3,
19. Teutschbein, C., and Seibert, J., (2013), “Is bias
correction of regional climate model (RCM) simulations
possible for non-stationary conditions?”,
Hydrol. Earth Syst. Sci., Vol.17, pp.5061–5077
20. Rasmussen, J., Sonnenborg, T. O., Stisen, S., Seaby,
L. P., Christensen, B. S. B., and Hinsby, K., (2012),
“Climate change effects on irrigation demands and
minimum stream discharge: impact of bias-correction
method”, Hydrol. Earth Syst. Sci., Vol.16,
21. Johnson, F. and Sharma, A. (2011), “Accounting for
interannual variability: A comparison of options for
water resources climate change impact assessments”,
Water Resour. Res., Vol.47, W04508.
22. Irrigation water requirements. (1967), “Tech.
Release No. 21”, United States Dept. of Agr., Soil
Conservation Service, Washington, D.C.
23. George, B., Shende, S., Raghuwanshi, N., (2000),
“Development and testing of an irrigation scheduling
model”, Agric. Water Manag., Vol. 46 (2),