Expected Future Precipitation in Central Iraq Using LARS-WG Stochastic Weather Generator


The Middle East (ME) is characterized by its water shortage problem. This region with its arid climate is expected to be the most vulnerable in the world to the potential impacts of climate change. Iraq (located in ME) is seriously experiencing water shortage problem. To overcome this problem rain water harvesting can be used. In this study the applicability of the long-term weather generator model in downscaling daily precipitation Central Iraq is used to project future changes of precipitation based on scenario of seven General Circulation Models (GCMs) outputs for the periods of 2011-2030, 2046-2065, and 2080-2099. The results indicated that December-February and September-November periods, based on the ensemble mean of seven GCMs, showed an increasing trend in the periods considered; however, a decreasing trend can be found in March, April, and May in the future.

Share and Cite:

Osman, Y. , Al-Ansari, N. , Abdellatif, M. , Aljawad, S. and Knutsson, S. (2014) Expected Future Precipitation in Central Iraq Using LARS-WG Stochastic Weather Generator. Engineering, 6, 948-959. doi: 10.4236/eng.2014.613086.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Nimah, M.N. (2008) Water Resources (2008) Report of the Arab Forum for Environment and Development. In: Tolba M.K. and Saab, N.W., Eds., Arab Environment and Future Challenges, Chapter 5, Arab Forum for Environment and Development, Cairo, 63-74.
[2] Al-Ansari, N.A. (2013) Management of Water Resources in Iraq: Perspectives and Prognoses. Engineering, 5, 667-668.
[3] Al-Ansari, N.A., Ali, A. and Knutsson, S. (2014) Present Conditions and Future Challenges of Water Resources Problems in Iraq. Journal of Water Resource and Protection, 6, 1066-1098.
[4] UN (2010) Water Resources Management White Paper, United Nations Assistance Mission for Iraq, United Nations Country Team in Iraq. 20 p.
[5] Al-Ansari, N.A., Knutsson, S. and Ali, A. (2012) Restoring the Garden of Eden, Iraq. Journal of Earth Sciences and Geotechnical Engineering, 2, 53-88.
[6] Al-Ansari, N.A., Ezz-Aldeen, M., Knutsson, S. and Zakaria, S. (2013) Water Harvesting and Reservoir Optimization in Selected Areas of South Sinjar Mountain, Iraq. Journal of Hydrologic Engineering, 18, 1607-1616.
[7] Al-Ansari, N.A., Zakaria, S., Mustafa, Y.T., Ahmad, P., Ghafour, B. and Knutsson, S. (2013) Development of Water Resources in Koya City, Iraq. 1st International Symposium on Urban Development of Koya, Koya City, 16-17 December 2013, 91-98.
[8] Zakaria, S. (2014) Rainwater Harvesting (RWH) North of Iraq. Ph.D. Thesis, Lulea University of Technology, Lulea.
[9] Zakaria, S., Al-Ansari, N., Mustafa, Y., Alshibli, M. and Knutsson, S. (2013) Macro Rain Water Harvesting Network to Estimate Annual Runoff at Koysinjaq (Koya) District, Kurdistan Region of Iraq. Engineering, 5, 956-966.
[10] Zakaria, S., Al-Ansari, N.A., Mustafa, Y., Mohammed, D.A., Knutsson, S., Ahmed, P. and Ghafour, B. (2013) Rainwater Harvesting at Koysinjaq (Koya), Kurdistan Region, Iraq. Journal of Earth Sciences and Geotechnical Engineering, 3, 25-46.
[11] Zakaria, S., Al-Ansari, N.A. and Knutsson, S. (2013) Historical and Future Climatic Change Scenarios for Temperature and Rainfall for Iraq. Journal of Civil Engineering and Architecture, 7, 1574-1594.
[12] Zakaria, S., Al-Ansari, N. and Knutsson, S. (2013) Wheat Yield Scenarios for Rainwater Harvesting at Northern Sinjar Mountain, Iraq. Natural Science, 5, 1057-1068.
[13] Wilby, R.L., Dawson, C.W. and Barrow, E.M. (2002) SDSM—A Decision Support Tool for the Assessment of Regional Climate Change Impacts. Environmental Modelling & Software, 17, 145-157.
[14] Dibike, Y.B. and Coulibaly, P. (2005) Hydrologic Impact of Climate Change in the Saguenay Watershed: Comparison of Downscaling Methods and Hydrologic Models. Journal of Hydrology, 307, 145-163.
[15] Kilsby, C.G., Jones, P.D., Burton, A., Ford, A.C., Fowler, H.J., Harpham, C., James, P., Smith, A. and Wilby, R.L. (2007) A Daily Weather Generator for Use in Climate Change Studies. Environmental Modelling and Software, 22, 1705-1719.
[16] Wilks, D.S. and Wilby, R.L. (1999) The Weather Generation Game: A Review of Stochastic Weather Models. Progress in Physical Geography, 23, 329-357.
[17] Racsko, P., Szeidl, L. and Semenov, M. (1991) A Serial Ap-proach to Local Stochastic Weather Models. Ecological Modelling, 57, 27-41.
[18] Bruhn, J.A., Fry, W.E. and Fick, G.W. (1980) Simulation of Daily Weather Data Using Theoretical Probability Distributions. Journal of Applied Meteorology, 19, 1029-1036.
[19] Bruhn, J.A. (1980) A Stochastic Model for the Simulation of Daily Weather. Protection Ecology, 2, 199-208.
[20] Nicks, A.D. and Harp, J.F. (1980) Stochastic Generation of Temperature and Solar Radiation Data. Journal of Hydrology, 48, 1-17.
[21] Richardson, C.W. (1981) Stochastic Simulation of Daily Precipitation, Temperature, and Solar Radiation. Water Resources Research, 17, 182-190.
[22] Richardson, C.W. and Wright, D.A. (1984) WGEN: A Model for Generating Daily Weather Variables. US Department of Agriculture, Agricultural Research Service, ARS-8, United States Department of Agriculture, Agricultural Research Services, Washington DC, 83 p.
[23] Schoof, J.T., Arguez, A., Brolley, J. and O’Brien, J.J. (2005) A New Weather Generator Based on Spectral Properties of Surface Air Temperatures. Agricultural and Forest Meteorology, 135, 241-251.
[24] Riha, S.J., Wilks, D.S. and Simoens, P. (1996) Impact of Temperature and Precipitation Variability on Crop Model Predictions. Climatic Change, 32, 293-311.
[25] Hartkamp, A.D., White, J.W. and Hoogentoom, G. (2003) Comparison of Three Weather Generators for Crop Modelling: A Case Study for Subtropical Environments. Agricultural Systems, 76, 539-560.
[26] Bannayan, M. and Hoogenboom, G. (2008) Weather Analogue: A Tool for Real-Time Prediction of Daily Weather Data Realizations Based on a Modified k-Nearest Neighbor Approach. Environmental Modelling & Software, 23, 703-713.
[27] Semenov, M.A. (2006) Using Weather Generators in Crop Modelling. Acta Horticulturae, 707, 93-100.
[28] Wilks, D.S. (1992) Adapting Stochastic Weather Generation Algorithms for Climate Changes Studies. Climatic Change, 22, 67-84.
[29] Bardossy, A. (1998) Generating Precipitation Time Series Using Simulated Annealing. Water Resources Research, 34, 1737-1744.
[30] Semenov, M.A. and Barrow, E.M. (1997) Use of a Stochastic Weather Generator in the Development of Climate Change Scenarios. Climatic Change, 35, 397-414.
[31] Semenov, M.A., Brooks, R.J., Barrow, E.M. and Richardson, C.W. (1998) Comparison of the WGEN and LARS-WG Stochastic Weather Generators for Diverse Climates. Climate Research, 10, 95-107.
[32] Semenov, M.A. (2008) Simulation of Extreme Weather Events by a Stochastic Weather Generator. Climate Research, 35, 203-212.
[33] IPCC (2007) Climate Change 2007: Climate Change Impacts, Adaptation and Vulnerability. Cambridge University Press, Geneva.
[34] Al-Ansari, N.A., Abdellatiff, M., Zakaria, S., Mustafa, Y.T. and Knutsson, S. (2014) Future Prospects for Macro Rain-water Harvesting (RWH) Technique in North East Iraq. Journal of Water Resource and Protection, 6, 403-420.
[35] Semenov, M.A. and Stratonovitch, P. (2010) Use of Multi-Model Ensembles from Global Climate Models for Assessment of Climate Change Impacts. Climate Research, 41, 1-14.
[36] Semenov, M.A. (2007) Development of High-Resolution UKCIP02-Based Climate Change Scenarios in the UK. Agricultural and Forest Meteorology, 144, 127-138.
[37] Semeov, M.A. and Barrow, E.M. (2002) LARS-WG—A Stochastic Weather Generator for Use in Climate Impact Studies. Version 3.0 User Manual, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK, 27 p.

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.