Impacts of Climate Change on Water Resources of Greater Zab and Lesser Zab Basins, Iraq, Using Soil and Water Assessment Tool Model

Authors: Nahlah Abbas, Saleh A. Wasimi, Nadhir Al-Ansari

Abstract:

The Greater Zab and Lesser Zab are the major tributaries of Tigris River contributing the largest flow volumes into the river. The impacts of climate change on water resources in these basins have not been well addressed. To gain a better understanding of the effects of climate change on water resources of the study area in near future (2049-2069) as well as in distant future (2080-2099), Soil and Water Assessment Tool (SWAT) was applied. The model was first calibrated for the period from 1979 to 2004 to test its suitability in describing the hydrological processes in the basins. The SWAT model showed a good performance in simulating streamflow. The calibrated model was then used to evaluate the impacts of climate change on water resources. Six general circulation models (GCMs) from phase five of the Coupled Model Intercomparison Project (CMIP5) under three Representative Concentration Pathways (RCPs) RCP 2.6, RCP 4.5, and RCP 8.5 for periods of 2049-2069 and 2080-2099 were used to project the climate change impacts on these basins. The results demonstrated a significant decline in water resources availability in the future.

Keywords: Tigris River, climate change, water resources, SWAT.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1132274

References:

[1] H. Tabari, and P. Willems, 2016. Daily Precipitation Extremes in Iran: Decadal Anomalies and Possible Drivers. Journal of American Water Resources Association 52 (2): 541-599, DOI: 10.1111/1752-1688.12403.
[2] M. A. Mimikou, E. Baltas, E. Varanou, and K. Pantazis, 2000. Regional Impacts of Climate Change on Water Resources Quantity and Quality Indicators. Journal of Hydrology 234(1): 95-109, DOI:10.1016/S0022-1694(00)00244-4.
[3] J. M. Winter and E. A. B. Eltahir, 2012. Modeling the Hydroclimatology of the Midwestern United States. Part 1: Current Climate. Climate Dynamics 38(3-4): 573-593, DOI:10.1007/s00382-011-1182-2.
[4] S. Selvanathan K. R. Sreetharan, D. Smirnov, J. Choi and M. Mampara, 2016. Developing Peak Discharges for Future Flood Risk Studies Using IPCC's CMIP5 Climate Model Results and USGS WREG Program. Journal of the American Water Resources Association 52 (4): 979-992, DOI: 10.1111/1752-1688.12407.
[5] UN-ESCWA and BGR, 2013. United Nations Economic and Social Commission for Western Asia; BundesanstaltfürGeowissenschaften und Rohstoffe. Inventory of Shared Water Resources in Western Asia. Beirut.
[6] N. Al-Ansari, S. Abdellatif, Ali and S. Knutsson, 2014. Long Term Effect of Climate Change on Rainfall in Northwest Iraq. Central European Journal of Engineering 4 (3): 250-263.
[7] I. E.Issa, N. Al-Ansari, G. Sherwany& S. Knutsson, Expected future of water resources within Tigris-Euphrates rivers basin, Iraq. Journal of Water Resource and Protection, 6, 2014, 421-432.
[8] J. G. Arnold, R. Srinivasan, R. S. Muttiah and J. R. Williams, 1998. Large Area Hydrologic Modeling and Assessment Part I: Model Development, Wiley Online Library.
[9] S. L. Neitsch, J. G Arnold, J. R Kiniry, R Williams and K. W King, 2005. Soil and water assessment tool theoretical documentation. Grassland. Soil and Water Research Laboratory, Temple, TX.
[10] W. H Green and G. A. Ampt, 1911. Studies on Soil Physics, Journal of Agricultural Science 4 (1): 1-24.
[11] J. L. Monteith, 1965. Evaporation and the Environment, in the State and Movement of Water in Living Organisms. Symposia of the Society of Experimental Biology 19:205-234.
[12] C. H. B. Priestley and R. J. Taylor, 1972. On the Assessment of Surface Heat Flux and Evaporation Using Large-Scale Parameters. Bulletin of American Meteorological Society 100(2): 81-92.
[13] G. L. Hargreaves, G. H. Hargreaves and J. P. Riley, 1985. Agricultural Benefits for Senegal River Basin. Journal of Irrigation and Drainage Engineering 111(2): 113-124.
[14] Jet Propulsion Laboratory California of Institute, 2012. Advanced Spacebome Thermal Emission and Reflection Radiometer, viewed 12, May 2015, https://asterweb.jpl.nasa.gov/gdem-wist.asp.
[15] European Environment Agency,2006, Spatial development of land use, viewed 23 May 2015, https://www.eea.europa.eu/data-and-maps.
[16] Food and Agriculture Organization, 1995. The digital soil map of the world and derived soil properties, Version 3.5, Rome
[17] K. C. Abbaspour, J. Yang, I. Maximov, R. Siber, K. Bogner, J. Mieleitner, J. Zobrist and R. Srinivasan, 2007. Modelling Hydrology and Water Quality in the Pre-Alpine/Alpine Thur Watershed Using SWAT. Journal of Hydrology 333(2-4): 413-430, DOI: 10.1016/j.jhydrol.2006.09.014.
[18] J. E. Nash and J.V. Sutcliffe, River flow forecasting through conceptual models part I—A discussion of principles. Journal of hydrology, 10(3), 1970, 282-290.
[19] D. N. Moriasi, J. G. Arnold, M. W. Van Liew, R. L. Bingner, R. D. Harmel and T. L Veith, 2007. Model evaluation guidelines for systematic quantification of accuracy in watershed simulations. Transactions of the ASABE 50(3): 885-900.
[20] E. P. Maurer, L. Brekke, T. Pruitt, B. Thrasher, J. Long, P. Duffy, M. Dettinger, D. Cayan& J. Arnold, An enhanced archive facilitating climate impacts and adaptation analysis. Bulletin of the American Meteorological Society, 95(7), 2014, 1011-1019.
[21] R. Cibin, K. P. Sudheer and I. Chaubey, Sensitivity and identifiability of stream flow generation parameters of the SWAT model. Hydrological processes, 24(9), 2010, 1133-1148.
[22] T. L. Veith, M. W. Van Liew, D. D. Bosch, and J. G. Arnold, 2010. Parameter Sensitivity and Uncertainty in SWAT: A Comparison across Five USDA-ARS Watersheds. Transactions of the ASABE 53 (5): 1477-1486.
[23] Z Li, Z. Xu, Q. Shao and J. Yang, 2009. Parameter Estimation and Uncertainty Analysis of SWAT Model in Upper Reaches of the Heihe River Basin. Hydrological Processes 23(19): 2744-2753.
[24] C. Santhi, J. G. Arnold, J. R. Williams, W. A. Dugas, R. Srinivasan and L. M. Hauck, 2001. Validation of the Swat Model on a Large Rwer Basin with Point and Nonpoint Sources1. Journal of the American Water Resources Association 37 (5):1169-1188.
[25] P. Ndomba, F. Mtalo and A. Killingtveit, 2008. SWAT Model Application in a Data Scarce Tropical Complex Catchment in Tanzania. Physics and Chemistry of the Earth Parts A/B/C 33 (8): 626-632.