Zoning Map of Drought Characteristics under Climate Change Scenario using Copula Method in the Zayandeh Roud River Catchment

Document Type : Research Paper


1 Ph. D Student, Department. of Hydrology and Water Resources, Faculty of Water Science, Shahid Chamran University of Ahvaz, Iran

2 Professor, Department. of Hydrology and Water Resources, Faculty of Water Science, Shahid Chamran University of Ahvaz, Iran.

3 Associate Professor, Department. of Hydrology and Water Resources, Faculty of Water Science, Shahid Chamran University of Ahvaz, Iran.

4 Professor, Department of Water Engineering, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.


Drought is one of the extreme events that can impact vast areas gradually over time. Also understanding the implications of climate change on drought is important for water resources management in order to manage the available water resources in the basin appropriately. Having better understanding of drought condition, drought indices were developed. Several drought indices are used for identifying and quantifying droughts that among them the standardized precipitation index (SPI) provides proper results. Based on each drought indices, drought characteristics can be calculated namely drought duration and drought severity. Drought characteristics are highly correlated to each other. Trusting on one of the drought characteristics for managing the water resources may lead to inappropriate understanding of drought condition. Therefore, it is important to notice all characteristics together by using a joint distribution function that among them copula function is prevalently used in hydrology studies. Several studies were examined the impact of climate change on the drought conditions by using different drought indices in many basins in the word and Iran (Bazrafshan et al., 2015, Kouchaki ei al. 2007, Mahsafar, 2011, Eghtedarnejad et al., 2016, Naserzadeh and Ahmadi, 2012, Hoffman et al., 2009, Kirono et al., 2011, Selvaraju and. Baas, 2007, Lee et al., 2013, Serinaldi et al., 2009, Mirabbasi et al., 2013). There have been many studies which using copula function in order to compute the return period of the drought (Abbasian et al., 2014, Golian, 2010, Serinaldi et al., 2009, Mirabbasi et al., 2016, Maddadgar and Moradkhani, 2011, Chen et al., 2011).
Therefore, in this study drought condition was analyzed by using copula under climate change condition to have a better understanding of future drought situation and the return periods of drought events in the future. The SPI was used to extract the drought duration and drought severity in the ZayandehRoud River basin for a historical period (1979-2008), and the far future (2058-2099) by using 15 GCM models from the IPCC Fifth Assessment Report (AR5) scenarios. A significant past drought event in the basin was used as a benchmark with severity of -4.39 and duration of 6 months. The Archimedean and Elliptical families of copula functions were used to construct the joint distribution functions for evaluating the drought return periods in the basin. Results from historical analysis show that the return period of significant past drought is about 5 years and this period will increase to about 25 years in the future.


Main Subjects

1-Abbasian, M., Jalali, S., Mousavi Nadoushani, S., 2014. Multivariate Flood Frequency Analysis Using Copula Function and Parametric and Nonparametric Margin Distributions. Modares Civil Engineering Journal, 14(4),pp.81-92 . (In Persian).
 2-Bazrafshan, J., Hojaji, S. and Hasheminasab, A., 2015. Impact of Future Climate Change on the Possibilities of Transferring Drought Classes in Iran's Limited Climate (Case study: Bandar Anzali and Bushehr stations). Journal of Water and Soil Conservation, 22(1), pp.131-150. (In Persian)
3-Chen L, Singh V.P, and Guo S. 2011. Drought Analysis Based on Copulas. Symposium on Data-Driven Approaches to Droughts, Paper 45.
4-Chen, L. Singh, VP. Guo, S. Mishra, AK. Guo, J. 2012. Drought analysis using copulas. Journal of Hydrologic Engineering, 18, pp.797-808.
5-Chen, YD. Zhang, Q. Xiao, M. Singh, VP, 2013. Evaluation of risk of hydrological droughts by the trivariate Plackett copula in the East River basin (China). Natural Hazards, 68, pp.529-47.
6-Eghtedarnejad, M., Bazrafshan, A., Sadeghi Lari, A., 2016. In the analysis of meteorological drought characteristics and SDI and RDI, SPI and Comparative Evaluation of Hydrological Indices (Case Study: Bam Plain). Water and Soile Science, 26(2),pp.69-81. (In Persian).
7-Golian, S., 2010. Flood Prediction Using Rainfall Threshold Method Based on Spatial Distribution. Thesis, AmirKabir Tecnology University of Tehran, Iran. (In Persian).
8-Hoffman, MT. Carrick, P. Gillson, L. West, A. 2009. Drought, climate change and vegetation response in the succulent karoo, South Africa. South African Journal of Science ,105,pp.54-60.
9-Kirono, D. Kent, D. Hennessy, K. Mpelasoka, F. 2011. Characteristics of Australian droughts under enhanced greenhouse conditions: Results from 14 global climate models. Journal of Arid Environments, 75, pp.566-75.
10-Kouchaki, A., Nasiri, M. and Kamali, G., 2007. Study of Iran Index in Climate Change Conditions. Iranian Journal of Field Crops Research, 5(1), pp.133-142. (In Persian).
11- Lee, T. Modarres, R. Ouarda, T. 2013. Data‚Äźbased analysis of bivariate copula tail dependence for drought duration and severity. Hydrological Processes, 27, pp.1454-63.
12- Li, C. Singh, VP. Mishra, AK. 2013. A bivariate mixed distribution with a heavy-tailed component and its application to single-site daily rainfall simulation. Water Resources Research, 49, pp.767-89.
13- Madadgar, S. Moradkhani, H. 2011. Drought analysis under climate change using copula. Journal of Hydrologic Engineering, 18, pp.746-59.
14-Mahsafar, H., 2011. Climate change effects on Water Bill on Lake Urmia. Iran Water Resources Research, 7(1), pp.47-58. (In Persian).
15- McKee, TB. Doesken, NJ. Kleist, J. 1993. The relationship of drought frequency and duration to time scales. Proc. Proceedings of the 8th Conference on Applied Climatology. American Meteorological Society Boston. MA. 17:179-83.
16- Mirabbasi, R. Anagnostou,  E. N. Fakheri-Fard, A. Dinpashoh, Y. Eslamian, S. 2013. Analysis of meteorological drought in northwest Iran using the Joint Deficit Index. Journal of Hydrology, 492, pp.35–48.
 17- Mousavi, S-F. 2005. Agricultural drought management in Iran. Proc. Water Conservation, Reuse, and Recycling: Proceedings of an Iranian-American Workshop. National Academies Press, pp.106-13.
18- Naserzadeh, M., Ahmadi, A., 2012. Performance Evaluation of Meteorological Drought Indicators in Drought Evaluation and its Zoning in Qazvin Province. Scientific Journals Management System, 12(162), pp.27-141. (In Persian).
19- Nelsen, RB. 2007. An introduction to copulas. Springer Science & Business Media.
20- Safavi, HR. Esfahani, MK. Zamani, AR. 2014. Integrated index for assessment of vulnerability to drought, case study: Zayandehrood River Basin, Iran. Water Resources Management, 28, pp.1671-88.
21- Selvaraju, R. Baas, S. 2007. Climate Variability and Change: Adaptation to Drought in Bangladesh: a Resource Book and Training Guide. Food & Agriculture Org.
22- Serinaldi, F. Bonaccorso, B. Cancelliere, A. Grimaldi, S. 2009. Probabilistic characterization of drought properties through copulas. Physics and Chemistry of the Earth, Parts A/B/C 34, pp.596-605.
23- Shiau, J. 2006. Fitting drought duration and severity with two-dimensional copulas. Water Resources Management, 20, pp.795-815.
24- Thrasher, B. Xiong, J. Wang, W. Melton, F. Michaelis, A. Nemani, R. 2013. Downscaled climate projections suitable for resource management. Eos. Transactions American of Geophysical Union, 94, pp.321-3.
25- Wayne, G. 2013. The beginner’s guide to representative concentration pathways. skeptical science. Version 1.0. http://www.skepticalscience.com/rcp.php.
26- Xu, K. Yang, D. Xu, X. Lei, H. 2015. Copula based drought frequency analysis considering the spatio-temporal variability in Southwest China. Journal of Hydrology 527:630-40.
27- Yan, J. 2007. Enjoy the joy of copulas: with a package copula. Journal of Statistical Software, 21, pp.1-21.
28- Yang W. 2010. Drought analysis under climate change by application of drought indices and copulas, Dissertations and Theses, Portland State University, Portland. 716P.
29- Yevjevich, VM. 1967. An objective approach to definitions and investigations of continental hydrologic droughts. Hydrology Papers (Colorado State University).no. 23.
Volume 42, Issue 1
March 2019
Pages 145-160
  • Receive Date: 05 January 2017
  • Revise Date: 14 July 2017
  • Accept Date: 16 July 2017
  • Publish Date: 21 March 2019