Abstract
The unidirectional trends in rainfall and rainfall-related extremes in Iraq have been assessed using long-term daily rainfall data (1965–2015). The modified version of Man-Kendall (m-MK) test which can discriminate the multi-scale variability from unidirectional trend was used along with Mann-Kendall (MK) test to confirm the trends in the presence of long-term persistence (LTP). The MK test revealed decrease in annual number of rainy days, heavy rainfall days, and consecutive wet days at 60, 53, and 47% stations, respectively, and the same indices during winter at 47, 47, and 33% stations, respectively. Significant decrease in annual and winter total rainfall was also found at a few stations. An increasing tendency in dry spell was observed due to the decrease in total rainfall and the number of rainy days; however, it was still not significant in most of the stations. The Student’s t test and F test revealed significant changes in daily rainfall mean and variability between two 30-year periods, 1965–1994 and 1986–2015. The m-MK test confirmed the results obtained using the MK test in most of the stations. However, the number of stations with significant change was found to decrease when the m-MK test was used. This indicates that some of the significant changes estimated by MK test were due to the presence of LTP. The obtained results confirmed the increase in dry spells and droughts in the region.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Aguilar E, Peterson TC, Obando PR, Frutos R, Retana JA, Solera M, …, Valle VE 2005) Changes in precipitation and temperature extremes in Central America and northern South America, 1961–2003. J Geophys Res: Atmos 110(D23). https://doi.org/10.1029/2005JD006119
Ahmed K, Shahid S, Chung E-S, Ismail T, Wang X (2017) Spatial distribution of secular trends in annual and seasonal precipitation over Pakistan. Clim Res. https://doi.org/10.3354/cr01489
Allan RP, Soden BJ (2008) Atmospheric warming and the amplification of precipitation extremes. Science 321(5895):1481–1484. https://doi.org/10.1126/science.1160787
Al-Qinna MI, Hammouri NA, Obeidat MM, Ahmad FY (2011) Drought analysis in Jordan under current and future climates. Clim Chang 106(3):421–440. https://doi.org/10.1007/s10584-010-9954-y
Al-Salihi AM, Al-Lami AM, Altimimi YK (2014) Spatiotemporal analysis of annual and seasonal rainfall trends for Iraq. Al-Mustansiriyah J Sci 25(1):153–168
AlSarmi SH, Washington R (2014) Changes in climate extremes in the Arabian peninsula: analysis of daily data. Int J Climatol 34(5):1329–1345. https://doi.org/10.1002/joc.3772
Amin MT, Mahmoud SH, Alazba AA (2016) Observations, projections and impacts of climate change on water resources in Arabian peninsula: current and future scenarios. Environ Earth Sci 75(10):1. https://doi.org/10.1007/s12665-016-5684-4
Batisani N, Yarnal B (2010) Rainfall variability and trends in semi-arid Botswana: implications for climate change adaptation policy. Appl Geogr 30(4):483–489. https://doi.org/10.1016/j.apgeog.2009.10.007
Davini P, von Hardenberg J, Corti S (2015) Tropical origin for the impacts of the Atlantic multidecadal variability on the Euro-Atlantic climate. Environ Res Lett 10(9):094010. https://doi.org/10.1088/1748-9326/10/9/094010
Ehsanzadeh E, Adamowski K (2010) Trends in timing of low stream flows in Canada: impact of autocorrelation and long-term persistence. Hydrol Process 24(8):970–980. https://doi.org/10.1002/hyp.7533
Fathian F, Morid S, Kahya E (2015) Identification of trends in hydrological and climatic variables in Urmia Lake basin, Iran. Theor Appl Climatol 119(3–4):443–464. https://doi.org/10.1007/s00704-014-1120-4
Giorgi F, Lionello P (2008) Climate change projections for the Mediterranean region. Glob Planet Chang 63(2):90–104. https://doi.org/10.1016/j.gloplacha.2007.09.006
Goodyear EJ (2009) The state of disaster risk reduction in Iraq
Hamed KH (2008) Trend detection in hydrologic data: the Mann–Kendall trend test under the scaling hypothesis. J Hydrol 349(3-4):350363–350363. https://doi.org/10.1016/j.jhydrol.2007.11.009
Hirsch RM, Slack JR (1984) A nonparametric trend test for seasonal data with serial dependence. Water Resour Res 20(6):727–732. https://doi.org/10.1029/WR020i006p00727
IPCC (2007) Climate Change 2007: impacts, adaptation and vulnerability. In: Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE (eds) Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge
IPCC (2013) Climate change 2013: the physical science basis. In: Stocker TF, Qin D, Plat-tner G-K, Tignor M, Allen SK, Boschung J, Nauels A, Xia Y, Bex V, Midgley PM (eds) Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge 1535 pp
Jaradat AA (2003) Agriculture in Iraq: resources, potentials, constraints, research needs and priorities. Food Agric Environ 1(2):160–166
Kendall MG (1948) Rank correlation methods. Griffin, Oxford
Khidher SA, Pilesjö P (2015) The effect of the North Atlantic oscillation on the Iraqi climate 1982–2000. Theor Appl Climatol 122(3–4):771–782. https://doi.org/10.1007/s00704-014-1327-4
Koutsoyiannis D (2003) Climate change, the Hurst phenomenon, and hydrological statistics. Hydrol Sci J 48(1):3–24. https://doi.org/10.1623/ hysj.48.1.3.43481
Kumar S, Merwade V, Kam J, Thurner K (2009) Streamflow trends in Indiana: effects of long term persistence, precipitation and subsurface drains. J Hydrol 374(1):171–183. https://doi.org/10.1016/j.jhydrol.2009.06.012
Lacombe G, Hoanh CT, Smakhtin V (2012) Multi-year variability or unidirectional trends? Mapping long-term precipitation and temperature changes in continental Southeast Asia using PRECIS regional climate model. Clim Chang 113(2):285–299. https://doi.org/10.1007/s10584-011-0359-3
Lelieveld J, Hadjinicolaou P, Kostopoulou E, Chenoweth J, El Maayar M, Giannakopoulos C, Hannides C, Lange MA, Tanarhte M, Tyrlis E, Xoplaki E (2012) Climate change and impacts in the eastern Mediterranean and the Middle East. Clim Chang 114(3):667–687. https://doi.org/10.1007/s10584-012-0418-4
Lu X, Wang L, Pan M, Kaseke KF, Li B (2016) A multi-scale analysis of Namibian rainfall over the recent decade—comparing TMPA satellite estimates and ground observations. J Hydrol: Reg Stud 8:59–68. https://doi.org/10.1016/j.ejrh.2016.07.003
Mann HB (1945) Nonparametric tests against trend. Econometrica 13(3):245–259. https://doi.org/10.2307/1907187
Mehta VM (2017) Modern observers riding decadal hydrologic cycle. In: natural decadal climate variability: societal impacts. CRC press, Florida
Milly PC, Dunne KA, Vecchia AV (2005) Global pattern of trends in streamflow and water availability in a changing climate. Nature 438(7066):347–350. https://doi.org/10.1038/nature04312
Modarres R, Sarhadi A, Burn DH (2016) Changes of extreme drought and flood events in Iran. Glob Planet Chang 144:67–81. https://doi.org/10.1016/j.gloplacha.2016.07.008
Najafi MR, Moazami S (2015) Trends in total precipitation and magnitude–frequency of extreme precipitation in Iran, 1969–2009. Int J Climatol 36(4):1863–1872. https://doi.org/10.1002/joc.4465
Pour SH, Harun SB, Shahid S (2014) Genetic programming for the downscaling of extreme rainfall events on the East Coast of peninsular Malaysia. Atmosphere 5(4):914–936. https://doi.org/10.3390/atmos5040914
Robaa ESM, Al-Barazanji Z (2015) Mann-Kendall trend analysis of surface air temperatures and rainfall in Iraq. IDOJARAS 119(4):493–514
Sa’adi Z, Shahid S, Ismail T, Chung E, Wang X (2017) Distributional changes in rainfall and river flow in Sarawak, Malaysia. Asia-Pac J Atmos Sci. https://doi.org/10.1007/s13143-017-0051-2
Salman AS, Shahid S, Ismail T, Chung E, Al-Abadi AA (2017) Long-term trends in daily temperature extremes in Iraq. Atmos Res 198:97–107. https://doi.org/10.1016/j.atmosres.2017.08.011
Samuels R, Smiatek G, Krichak S, Kunstmann H, Alpert P (2011) Extreme value indicators in highly resolved climate change simulations for the Jordan River area. J Geophys Res: Atmos 116(D24):1–9. https://doi.org/10.1029/2011JD016322
Sen PK (1968) Estimates of the regression coefficient based on Kendall's tau. J Am Stat Assoc 63(324):1379–1389. https://doi.org/10.2307/2285891
Shahid S (2011) Trends in extreme rainfall events of Bangladesh. Theor Appl Climatol 104(3–4):489–499. https://doi.org/10.1007/s00704-010-0363-y
Shahid S, Wang X-J, Harun SB (2014) Unidirectional trends in rainfall and temperature of Bangladesh. IAHS-AISH Proceedings on 7th World Flow Regimes from International and Experimental Network Data-Water Conference, FRIEND-Water 2014 - Montpellier. Copernicus GmbH Publishers, p 177-182
Shahid S, Wang X-J, Harun SB, Shamsudin S, Ismail T, Minhans A (2016) Climate variability and changes in the major cities of Bangladesh: observations, possible impacts and adaptation. Reg Environ Chang 16(2):459–471. https://doi.org/10.1007/s10113-015-0757-6
Soltani M, Laux P, Kunstmann H, Stan K, Sohrabi MM, Molanejad M, …, Zawar-Reza P (2015) Assessment of climate variations in temperature and precipitation extreme events over Iran. Theor Appl Climatol 126(3-4):1–21. https://doi.org/10.1007/s00704-015-1609-5
Su BD, Jiang T, Jin WB (2006) Recent trends in observed temperature and precipitation extremes in the Yangtze River basin, China. Theor Appl Climatol 83(1-4):139–151. https://doi.org/10.1007/s00704-005-0139-y
Thomas J, Prasannakumar V (2016) Temporal analysis of rainfall (1871–2012) and drought characteristics over a tropical monsoon-dominated state (Kerala) of India. J Hydrol 534:266–280. https://doi.org/10.1016/j.jhydrol.2016.01.013
UNDP, Ragab R (2013) Water Governance in the Arab Region: Managing Scarcity and Securing the future
Wang XJ, Zhang JY, Ali M, Shahid S, He RM, Xia XH, Jiang Z (2016a) Impact of climate change on regional irrigation water demand in Baojixia irrigation district of China. Mitig Adapt Strateg Glob Chang 21(2):233–247. https://doi.org/10.1007/s11027-014-9594-z
Wang X-J, Zhang J-Y, Shahid S, Guan E-H, Wu Y-X, Gao J, He R-M (2016b) Adaptation to climate change impacts on water demand. Mitig Adapt Strateg Glob Chang 21(1):81–99. https://doi.org/10.1007/s11027-014-9571-6
Weisheimer A, Schaller N, O'Reilly C, MacLeod DA, Palmer T (2017) Atmospheric seasonal forecasts of the twentieth century: multi-decadal variability in predictive skill of the winter North Atlantic Oscillation (NAO) and their potential value for extreme event attribution. QJR Meteorol Soc 143(703):917–926. https://doi.org/10.1002/qj.2976
WMO (1996) Climatological normals (CLINO) for the period 1961-1990 = Normales climatologiques (CLINO) pour la période 1961–1990. The World Meteorological Organization 1996. WMO, Geneva
WMO (2016) Provisional WMO Statement on the Status of the Global Climate in 2016. http://public.wmo.int/en/media/press-release/provisional-wmo-statement-status-of-global-climate-2016
You Q, Kang S, Aguilar E, Yan Y (2008) Changes in daily climate extremes in the eastern and central Tibetan plateau during 1961–2005. J Geophys Res: Atmos 113(D7):1–17. https://doi.org/10.1029/2007JD009389
Zakhem BA, Kattaa B (2016) Investigation of hydrological drought using cumulative standardized precipitation index (SPI 30) in the eastern Mediterranean region (Damascus, Syria). J Earth Syst Sci 125(5):969–984. https://doi.org/10.1007/s12040-016-0703-0
Acknowledgements
The authors are grateful to the Iraq meteorological organization & seismology (IMOS) for providing daily rainfall data of Iraq. The authors are also grateful to the Ministry of Education Malaysia and Universiti Teknologi Malaysia (UTM) for providing financial support for this research through GUP grant no. Q.J130000.2522.10H36.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Salman, S.A., Shahid, S., Ismail, T. et al. Unidirectional trends in daily rainfall extremes of Iraq. Theor Appl Climatol 134, 1165–1177 (2018). https://doi.org/10.1007/s00704-017-2336-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00704-017-2336-x