Journals / Journal of Agricultural Sciences / 2026 / Volume: 32 Issue: 4

Drought Trends in Türkiye Under Global Warming Conditions

Fatih Sekendur(Meteoroloji Genel Müdürlüğü)0000-0001-6509-2952
Pages
—
Publication Date
2026-10-12
🏛️Bibliographic metadata and full text access for this article are provided via DergiPark.
DergiPark Record ↗
✨

AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

The findings revealed that the humid periods were more prevailing than the dry periods in these areas that have downward drought trend.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:The methods used in monitoring the increasing drought are vitally significant.
📊
Key Findings & Data:In this study, spatio-temporal comparison of drought trend and trend magnitude at 1, 6 and 12-month time scales according to SPI and SPEI indices was aimed by using meteorological observation data of 81 meteorological stations in Türkiye between 1980-2019.
💡
Conclusion & Impact:The findings revealed that the humid periods were more prevailing than the dry periods in these areas that have downward drought trend.
🔬Design:Research Article
📍Scope:2019 Verileri
⚙️Variables:Drought · SPI · SPEI

Abstract

The methods used in monitoring the increasing drought are vitally significant. In order to determine and monitor drought, many scientific studies have been carried out in our country, especially using the standardized precipitation index (SPI). However, due to increasing temperatures and evaporation, there is a need for studies showing the spatio-temporal change of drought at the country scale according to the standardized precipitation evapotranspiration index (SPEI), which also takes evaporation into account. The change in drought indices according to different evapotranspiration methods is also of interest. In this study, spatio-temporal comparison of drought trend and trend magnitude at 1, 6 and 12-month time scales according to SPI and SPEI indices was aimed by using meteorological observation data of 81 meteorological stations in Türkiye between 1980-2019. FAO-56 Penman-Monteith (PM) and Hargreaves (HG) reference evapotranspiration methods were used to calculate the SPEI index. Temporal trend analyses were conducted by Modified Mann-Kendall method and drought slope magnitude analyses by Sen’s Slope Estimator and spatial analyses by IDW method. According to the SPI index trend analysis for a 1, 6 and 12- month time scale, especially the drought in the Black Sea, the Marmara and Aegean Regions of Türkiye showed a significant downward trend while a significant upward trend of drought was seen in the other regions. The findings revealed that the humid periods were more prevailing than the dry periods in these areas that have downward drought trend. Unlike the SPI, the trend analysis of SPEIPM and SPEIHG index, downward trend of drought was only encountered in the coastal provinces of the Aegean region, the Central Black Sea, and the West Marmara Region. A significant upward trend of drought was observed in the majority of Central Anatolia, Eastern Anatolia, and Southeastern Anatolia Regions according to the SPEIPM and SPEIHG index.

🔖

Cite This Article

Sekendur, F., Ünlükara, A. (2026). Drought Trends in Türkiye Under Global Warming Conditions. Journal of Agricultural Sciences, Volume: 32 Issue: 4. https://doi.org/10.15832/ankutbd.1779288

📄 Full Text PDF Viewer

📄

PDF görüntüleyici hazırlanıyor...

References (60)

  1. Akacak A K & Taş İ (2021). Calculation of spatial precipitation with different spatial interpolation methods: A Case Study of The North Aegean Basin. (In Turkish) Turkish Journal of Agricultural and Natural Sciences 8(2): 528–539. https://doi.org/10.30910/turkjans.877581
  2. Aksoy H, Cetin M, Eris E, Burgan H I, Cavus Y, Yildirim I & Sivapalan M (2021). Critical drought intensity–duration–frequency curves based on total probability theorem–coupled frequency analysis. Hydrological Sciences Journal 66(8): 1337–1358. https://doi.org/10.1080/02626667.2021.1934473
  3. Allen R G, Pereira L S, Raes D & Smith M (1998). FAO irrigation and drainage paper No. 56. Food and Agriculture Organization of the United Nations.
  4. Beguería S, Vicente-Serrano S M, Reig F & Latorre B (2014). Standardized precipitation evapotranspiration index (SPEI) revisited: Parameter fitting, evapotranspiration models, tools, datasets and drought monitoring. International Journal of Climatology 34: 3001–3023. https://doi.org/10.1002/joc.3887
  5. Bera B, Shit P K, Sengupta N, Saha S & Bhattacharjee S (2021). Trends and variability of drought in the extended part of Chhota Nagpur plateau (Singbhum Protocontinent), India applying SPI and SPEI indices. Environmental Challenges, 5, 100310. https://doi.org/10.1016/j.envc.2021.100310
  6. Buishand T A (1982). Some methods for testing the homogeneity of rainfall records. Journal of hydrology 58(1-2): 11-27
  7. Çetin M, Aksoy H, Önöz B, Eriş E, Yüce M İ, Selek B, Aksu H, Burgan H İ, Eşit M, Çavuş Y & Orta S (2018). Deriving accumulated precipitation deficits from drought severity–duration–frequency curves: A case study in Adana province, Türkiye. In 1st International Congress on Agricultural Structures and Irrigation, Proceedings and Abstracts Book (pp. 39–48). Antalya, Türkiye. Çetin M (2020). Agricultural Water Use. Water Resources of Turkey, vol.2, 257-302.
  8. Collaud Coen M, Andrews E, Bigi A, Martucci G, Romanens G, Vogt F & Vuilleumier L (2020). Effects of the prewhitening method, the time granularity, and the time segmentation on the Mann–Kendall trend detection and the associated Sen's slope. Atmospheric Measurement Techniques 13(12): 6945–6964. https://doi.org/10.5194/amt-13-6945-2020
  9. Cox D R & Stuart A (1955). Some quick sign tests for trend in location and dispersion. Biometrika, 42(1–2): 80–95. https://doi.org/10.2307/2333424
  10. Dadaşer Çelik F, Cengiz E & Guzel O (2016). Trends in reference evapotranspiration in Turkey: 1975–2006. International Journal of Climatology, 36(4), 1733–1743. https://doi.org/10.1002/joc.4455
  11. Dai A (2011). Drought under global warming: A review. WIREs Climate Change, 2(1), 45–65. https://doi.org/10.1002/wcc.81
  12. El-Nesr M N, Abu-Zreig M M & Alazba A A (2010). Temperature trends and distribution in the Arabian Peninsula. American Journal of Environmental Sciences 6(2): 191–203.
  13. Gocic M & Trajkovic S (2013). Analysis of changes in meteorological variables using Mann–Kendall and Sen's slope estimator statistical tests in Serbia. Global and Planetary Change 100: 172–182. https://doi.org/10.1016/j.gloplacha.2012.10.014
  14. Guo E, Liu X, Zhang J, Wang Y, Wang C, Wang R & Li D (2017). Assessing spatiotemporal variation of drought and its impact on maize yield in Northeast China. Journal of Hydrology 553: 231–247. https://doi.org/10.1016/j.jhydrol.2017.07.060
  15. Hamed K H & Rao A R (1998). A modified Mann–Kendall trend test for autocorrelated data. Journal of Hydrology 204(1–4): 182–196. https://doi.org/10.1016/S0022-1694(97)00125-X
  16. Hargreaves G H & Samani Z A (1985). Reference crop evapotranspiration from temperature. Applied Engineering in Agriculture 1(2): 96–99.
  17. Heim R R (2002). A review of twentieth-century drought indices used in the United States. Bulletin of the American Meteorological Society, 83(8): 1149–1165. https://doi.org/10.1175/1520-0477-83.8.1149
  18. Hernandez E A & Uddameri V (2014). Standardized precipitation evaporation index (SPEI)-based drought assessment in semi-arid south Texas. Environmental Earth Sciences 71(6): 2491–2501. https://doi.org/10.1007/s12665-013-2897-7
  19. Jhajharia D, Dinpashoh Y, Kahya E, Singh V P & Fakheri-Fard A (2012). Trends in reference evapotranspiration in the humid region of northeast India. Hydrological Processes 26(3): 421–435. https://doi.org/10.1002/hyp.8140
  20. Kaur N, Yousuf A & Singh M J (2021). Long-term rainfall variability and trend analysis in lower Shivaliks of Punjab, India. Mausam, 72(3): 571–582. https://doi.org/10.54302/mausam.v72i3.1307
  21. Keskiner A D, Çetin, M, Şimşek M & Akın S (2020). Design of Small Earthen Dam reservoirs lying in drought-prone areas: An application to the Seyhan River Basin. (In Tukish) Teknik Dergi 31(5): 10189-10210. https://doi.org/10.18400/tekderg.505584
  22. Keskiner A D & Çetin M (2022). Determination of trend and magnitude of drought events in time and space: An application in the area of the Southeastern Anatolia Project (GAP). (In Turkish) Journal of Polytechnic. https://doi.org/10.2339/politeknik.1000596
  23. Kızılelma Y, Çelik M & Karabulut M (2015). Trend analyses of temperature and precipitations in Central Anatolia. (In Turkish) Turkish Geographical Review, 64: 1–10. https://doi.org/10.17211/tcd.90494
  24. Lettenmaier D P, Wood E F & Wallis J R (1994). Hydro-climatological trends in the continental United States, 1948–88. Journal of Climate, 7(4): 586–607. https://doi.org/10.1175/1520-0442(1994)007 2.0.CO;2
  25. Liu X & Zhang D (2013). Trend analysis of reference evapotranspiration in Northwest China: The roles of changing wind speed and surface air temperature. Hydrological Processes, 27(26), 3941–3948. https://doi.org/10.1002/hyp.9527
  26. McKee T B, Doesken N J & Kleist J (1993). The relationship of drought frequency and duration to time scales. In Proceedings of the 8th Conference on Applied Climatology (Vol. 17, No. 22, pp. 179–183). American Meteorological Society.
  27. Ortiz-Gómez R, Flowers-Cano R S & Medina-García G (2022). Sensitivity of the RDI and SPEI drought indices to different models for estimating evapotranspiration potential https://doi.org/10.1007/s11269-022-03154-9 in semiarid regions. Water Resources Management, 36(7): 2471–2492.
  28. Ölgen M K (2010). Spatial distribution of annual and seasonal rainfall variability over Turkey. (In Turkish) Aegean Geographical Journal 19(1): 85–95
  29. Özçelik Ş (2019). Drought analysis in Aegean Region with the standardized precipitation evapotranspiration index (In Turkish) (Master’s Thesis). Ege University, Graduate School of Natural and Applied Sciences.
  30. Palmer W C (1965). Meteorological drought (Research Paper No. 45). U.S. Weather Bureau.
  31. Pettitt A N (1979). A non‐parametric approach to the change‐point problem. Journal of the Royal Statistical Society: Series C (Applied Statistics), 28(2): 126-135
  32. Philip S, Kew S F, van Oldenborgh G J, Otto F, O′Keefe S, Haustein K, King A, Zegeye A, Eshetu Z & Hailemariam K (2017). Attribution analysis of the Ethiopian drought of 2015. Journal of Climate 31(6): 2465–2485. https://doi.org/10.1175/JCLI-D-17-0274.1
  33. Said A A, Cetin M & Yurtal R (2019). Drought assessment and monitoring using some drought indicators in the semi-arid Puntland State of Somalia. Fresenius Environmental Bulletin 28(11A): 8765–8772
  34. Salmi T, Maatta A, Anttila P, Ruoho-Airola T & Amnell T (2002). Detecting trends of annual values of atmospheric pollutants by the MannKendall test and Sen’s slope estimates – The Excel template application MAKESENS. Finnish Meteorological Institute.
  35. Sellinger C E (1996). Computer program for estimating evapotranspiration using the Thornthwaite method.
  36. Sen P K (1968). Estimates of the regression coefficient based on Kendall's tau. Journal of the American Statistical Association 63(324): 1379 1389. https://doi.org/10.1080/01621459.1968.10480934
  37. Shaker Sureh, F., Sattari, M. T., Rostamzadeh, H., & Kahya, E. (2024). Meteorological Drought Assessment and Prediction in Association with Combination of Atmospheric Circulations and Meteorological Parameters via Rule Based Models. Journal of Agricultural Sciences, 30(1), 61-78. https://doi.org/10.15832/ankutbd.1067486
  38. Sheffield J, Wood E J & Roderick M L (2012). Little change in global drought over the past 60 years. Nature, 491(7424): 435–438. https://doi.org/10.1038/nature11575
  39. Tabari H, Marofi S, Aeini A, Talaee P H & Mohammadi K (2011). Trend analysis of reference evapotranspiration in the western half of Iran. Agricultural and Forest Meteorology 151(2): 128–136. https://doi.org/10.1016/j.agrformet.2010.09.009
  40. Thom H C S (1958). A note on the gamma distribution. Monthly Weather Review, 86(4): 117–122. https://doi.org/10.1175/1520 0493(1958)086 2.0.CO;2
  41. Thornthwaite C W (1948). An approach toward a rational classification of climate. Geographical Review, 38(1): 55–94. https://doi.org/10.2307/210739
  42. Tirivarombo S, Osupile D & Eliasson P (2018). Drought monitoring and analysis: Standardised precipitation evapotranspiration index (SPEI) and Standardised precipitation index (SPI). Physics and Chemistry of the Earth, 106: 1–10. https://doi.org/10.1016/j.pce.2018.07.001
  43. Tonkaz T, Çetin M & Tülücü K (2007). The impact of water resources development projects on water vapor pressure trends in a semi-arid region, Turkey. Climatic Change 82(1–2): 195–209. https://doi.org/10.1007/s10584-006-9160-0
  44. Topçu E & Karaçor F (2020). Drought analysis of Erzurum station by using Standardized Precipitation Evapotranspiration Index and Aggregated Drought Index. Politeknik Dergisi, 24(2): 565–574. https://doi.org/10.2339/politeknik.682168
  45. Tran T V, Tran D X, Myint S W, Latorre-Carmona P, Ho D D, Tran P H & Dao H N (2019). Assessing spatiotemporal drought dynamics and its related environmental issues in the Mekong River delta. Remote Sensing, 11(23): 2742. https://doi.org/10.3390/rs11232742
  46. Tsakiris G, Pangalou D & Vangelis H (2007). Regional drought assessment based on the Reconnaissance Drought Index (RDI). Water Resources Management, 21(5), 821–833. https://doi.org/10.1007/s11269-006-9105-4
  47. Ülke A & Özkoca T (2018). Trend analyses of temperature data of Sinop, Ordu and Samsun provinces. (In Turkish) Gümüşhane University Journal of Science and Tecnology, 8(2), 455–463. https://doi.org/10.17714/gumusfenbil.351294
  48. Van der Schrier G, Jones P D & Briffa K R (2011). The sensitivity of the PDSI to the Thornthwaite and Penman–Monteith parameterizations for potential evapotranspiration. Journal of Geophysical Research: Atmospheres, 116(D3). https://doi.org/10.1029/2010JD015001
  49. Vicente-Serrano S, Beguería S & López-Moreno J I (2010). A multiscalar drought index sensitive to global warming: The standardized precipitation evapotranspiration index. Journal of Climate, 23(7): 1696–1718. https://doi.org/10.1175/2009JCLI2909.1
  50. Von Neumann J (1941). Distribution of the ratio of the mean square successive difference to the variance. The Annals of Mathematical Statistics, 12(4): 367-395
  51. Wable P S, Jha M K & Shekhar A (2019). Comparison of drought indices in a semi-arid river basin of India. Water Resources Management, 33(1): 75–102. https://doi.org/10.1007/s11269-018-2089-z
  52. Wang X, Zhuo L, Li C, Engel B A, Sun S & Wang Y (2019). Temporal and spatial evolution trends of drought in northern Shaanxi of China: 1960–2100. Theoretical and Applied Climatology, 139(3–4): 965–979. https://doi.org/10.1007/s00704-019-03024-2
  53. Wijngaard J B, Klein Tank A M G & Können G P (2003). Homogeneity of 20th century European daily temperature and precipitation series. International Journal of Climatology: A Journal of the Royal Meteorological Society 23(6): 679-692 World Meteorological Organization (2018). Guide to climatological practices (2nd ed.). WMO.
  54. Yang M, Yan D, Yu Y & Yang Z (2016). SPEI-based spatiotemporal analysis of drought in Haihe River Basin from 1961 to 2010. Advances in Meteorology, 2016, 1–10. https://doi.org/10.1155/2016/7658015
  55. Yin Y, Wu S, Chen & Dai E (2010a). Attribution analyses of potential evapotranspiration changes in China since the 1960s. Theoretical and Applied Climatology, 101(1): 19–28. https://doi.org/10.1007/s00704-009-0197-7
  56. Yin Y, Wu S & Dai E (2010b). Determining factors in potential evapotranspiration changes over China in the period 1971–2008. Chinese Science Bulletin, 55(29): 3329–3337. https://doi.org/10.1007/s11434-010-3289-y
  57. Yue S & Hashino M (2003). Temperature trends in Japan: 1900–1996. Theoretical and Applied Climatology, 75(1–2): 15–27. https://doi.org/10.1007/s00704-002-0717-1
  58. Yürekli K & Ünlükara A (2013). Comparing of SPI and SPEI for evaluating of global warming effects on drought. (In Turkish) In 3. International Bursa Water Congress (pp. 225–233). Bursa, Türkiye.
  59. Zhang X, Ren Y, Yin Z Y, Lin Z & Zheng D (2009). Spatial and temporal variation patterns of reference evapotranspiration across the Qinghai Tibetan Plateau during 1971–2004. Journal of Geophysical Research: Atmospheres, 114(D15). https://doi.org/10.1029/2009JD011753
  60. Çetin M, Aksoy H, Önöz B, Eriş E, Yüce M İ, Selek B, Aksu H, Burgan H İ, Eşit M, Çavuş Y & Orta S (2018). Deriving accumulated precipitation deficits from drought severity–duration–frequency curves: A case study in Adana province, Türkiye. In 1st International Congress on Agricultural Structures and Irrigation, Proceedings and Abstracts Book (pp. 39–48). Antalya, Türkiye. Çetin M (2020). Agricultural Water Use. Water Resources of Turkey, vol.2, 257-302.