In this study, drought tendency in Southeastern Anatolian Project (GAP) area was analyzed by using the Mann-Kendal (MK) and Theil-Sen Slope estimator (TSE) approaches. For this purpose, the data sets of the 3- and 12-month timescales, based on monthly rainfalls of rain gauging stations in the area, was considered in the study. There is a decreasing trend in the 53% of total number of months concerning with the data sets of the 3-month timescale for nine sites when the entire months of seven stations have a downward trend for the data sets related to the 12-month timescale. This shows that the tendency of drought increases at the longer periods of timescale. The direction and magnitude of trend in any station was detected with the TSE method.

Detection of Drought Tendency Based on Precipitation in Southeastern Anatolian Project (GAP) Region, Turkey

In this study, drought tendency in Southeastern Anatolian Project (GAP) area was analyzed by using the Mann-Kendal (MK) and Theil-Sen Slope estimator (TSE) approaches. For this purpose, the data sets of the 3- and 12-month timescales, based on monthly rainfalls of rain gauging stations in the area, was considered in the study. There is a decreasing trend in the 53% of total number of months concerning with the data sets of the 3-month timescale for nine sites when the entire months of seven stations have a downward trend for the data sets related to the 12-month timescale. This shows that the tendency of drought increases at the longer periods of timescale. The direction and magnitude of trend in any station was detected with the TSE method.

___

  • Abaurrea J, Asín J, Cebrián C C and García-Vera M A (2011). Trend analysis of water quality series based on regression models with correlated errors. Journal of Hydrology, 400: 341–352.
  • Abdul Aziz OI and Burn DH (2006). Trends and variability in the hydrological regime of the Mackenzie River Basin. Journal of Hydrology, 319: 282–294.
  • Altınbilek D (2004). Development and management of the Euphrates–Tigris basin. Water Resources Development 20: 15-33.
  • Beaumont P (1998). Restructuring of Water Usage in the Tigris-Euphrates Basin: the Impact of Modern Water Management Policies. Ed. Albert J, Bernhardsson M and Kenna R. Transformations of Middle Eastern Natural Environments: Legacies and Lessons. Yale School of Forestry and Environmental Studies, Bulletin Series No. 103, New Haven, Connecticut, USA, pp. 168–186.
  • Cox DR and Stuart A (1955). Some quick sign tests for trend in location and dispersion. Biometrika. 42, 80–95.
  • Dinpashoh Y, Jhajharia D, Fakheri-Fard A, Singh VP and Kahya E (2011). Trends in reference crop evapotranspiration over Iran. Jounal of Hydrology, 399: 422–433.
  • Duhan D and Pandey A (2013). Statistical analysis of long term spatial and temporal trends of precipitation during 1901–2002 at Madhya Pradesh, India. Atmospheric Research, 122: 136-149.
  • Espadafor M, Lorite IJ, Gavilán P and Berengena J (2011). An analysis of the tendency of reference evapotranspiration estimates and other climate variables during the last 45 years in Southern Spain. Agriculture Water Management 98: 1045–1061.
  • Giorgi F (2006). Climate change Hot-Spots. Geophysical. Research Letters, 33: L08707.
  • Hamed KH (2008). Trend detection in hydrologic data: The Mann-Kendall trend test under the scaling hypothesis. Journal of Hydrology, 349: 350–363.
  • Hamed KH and Rao AR (1998). A modified Mann-Kendall trend test for autocorrelated data. Journal of Hydrology, 204: 182-196.
  • Huth R (1999). Testing for trends in data unevenly distributed in time. Theoretical and Applied Climatology, 64: 151–162.
  • IPCC. (2007). Climate Change 2007: Synthesis Report, Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge.
  • Karabulut M and Cosun F (2009). Precipitation trend analyses in Kahramanmaras province. Cografi Bilimler Dergisi, 7: 65-83. (In Turkish)
  • Kibaroglu A and Unver IHO (2000). An institutional framework for facilitating cooperation in the Euphrates-Tigris River Basin. International Negotition: A Journal of Theory and Practice, 5: 311-330.
  • Kutiel H, Maheras P, Turkes M and Paz S (2002). North Sea – CaspianPattern (NCP) – an upper level atmospheric teleconnectionaffectingthe eastern Mediterranean – implications on the regional climate. Theoretical and Applied Climatology, 72: 173–192.
  • Liang LQ, Li LJ and Liu Q (2010). Temporal variation of reference evapotranspiration during 1961–2005 in the Taoer River Basin of Northest China. Agricultural and Forest Meteorology, 150: 298–306.
  • Ljung GM and Box GEP (1978). On a measure of lack of fit in time series models. Biometrika. 65, 297–303.
  • McKee TB, Doesken N J and Kleist J (1993). The Relationship of Drought Frequency And Duration of Time Scales. Eighth Conference on Applied Climatology, American Meteorological Society, Jan17-23, 1993, Anaheim CA, pp.179-186.
  • Morvaridi B (1990). Agrarian reform and land use policy in Turkey: Implications for the Southeast Anatolia Project. Land Use Policy. 7: 303-313.
  • Ozdogan M (2011). Climate change impacts on snow water availability in the Euphrates-Tigris basin. Hydrology and Earth System Sciences Discussions, 8: 3631-3666. Partal T and Kahya E (2006). Trend analysis in Turkish precipitation data. Hydrological Processes, 20: 2011-2026.
  • Sayemuzzaman M and Jha MK (2014). Seasonal and annual precipitation time series trend analysis in North Carolina, United States. Atmospheric Research, 137: 183–194.
  • Sen PK (1968). Estimates of the regression coefficient based on Kendall's tau. Journal of the American Statistical Association, 63: 1379–1389.
  • Some'e BS, Ezani A and Tabari H (2012). Spatiotemporal trends and change point of precipitation in Iran. Atmospheric Research, 113: 1–12.
  • Tabari H and Talaee PH (2011). Temporal variability of precipitation over Iran: 1966–2005. Journal of Hydrology, 396: 313–320.
  • Tang B, Tong L, Kang S and Zhang L (2011). Impacts of climate variability on reference evapotranspiration over 58 years in the Haihe river basin of north China. Agricultural Water Management, 98: 1660-1670.
  • Tatli H (2006). Analysis Mediterranean Precipitation Associated with the North Atlantic Oscillation Index (NAOI) via Hilbert-HuangTransformation. In Proceedings of the Conference on Water Observation and Information System for Decision Support (BALWOIS-2006). Ohrid, Republic of Macedonia, Paper No.A-329, 11.
  • Theil H (1950). A Rank Invariant Method of Linear and Polynomial Regression Analysis, part 3. Netherlands Akademie van Wettenschappen, Proceedings, 53, pp. 1397–1412.
  • Toros H (2012). Spatio-temporal precipitation change assessments over Turkey. International Journal of Climatology, 32: 1310-1325.
  • Turkes M and Erlat E (2003). Precipitation changes and variability inTurkey linked to the North Atlantic Oscillation during the period1930–2000. International Journal of Climatology, 23: 1771–1796.
  • Türkes M, Koç T and Sarıs F (2009). Spatiotemporal variability of precipitation total series overTurkey. International Journal of Climatology, 29: 1056-1074.
  • Unal YS, Deniz A, Toros H and Incecik S (2012). Temporal and spatial patterns of precipitation variability for annual, wet, and dry seasons in Turkey. International Journal of Climatology, 32: 392-405.
  • Unver IHO (1997). Southeastern Anatolia Project (GAP). Water Resources Development, 13: 453-483.
  • Von Storch H (1995). Misuses of Statistical Analysis In Climate Research. Ed. Storch HV and Navarra A. Analysis of Climate Variability: Applications of Statistical Techniques, Springer, Berlin, pp. 11–26.
  • Yenilmez F, Keskin F and Aksoy A (2011). Water quality trend analysis in Lake Eymir, Ankara. Journal of Physics and Chemistry of the Earth, 36: 135-140.
  • Yue S and Wang CY (2002). Applicability of prewhitening to eliminate the influence of serial correlation on the Mann–Kendall test. Water Resources Research, 38: 1068, doi:10.1029/2001WR000861.
  • Yue S and Pilon P (2003). Canadian streamflow trend detection: impact of serial and cross-correlation. Hydrological Sciences Journal, 48: 51–63.
  • Yurekli K. (2015). Impact of climate variability on precipitation in the Upper Euphrates–Tigris Rivers Basin of Southeast Turkey. Atmospheric Research, 154: 25-38.
  • Zhang Q, Xu CY, Zhang Z and Chen YD (2008). Changes of temperature extremes for 1960–2004 in Far-West China. Stochastic Environmental Research and Risk Assessment, 23: 721-735.
  • Zhang XT, Kang SZ, Zhang L and Liu JQ (2010). Spatial variation of climatology monthly crop reference evapotranspiration and sensitivity coefficients in Shiyang river basin of northwest China. Agricultural Water. Management, 97: 1506–1516.