Anomalies of precipitation and drought in objectively derived climate regions of Iran

Keywords: hierarchical cluster analysis, anomaly of precipitation, drought trend, Iran


By regionalizing precipitation in 113 synoptic stations in Iran, the characteristics of precipitations and the occurrence of droughts in each region were investigated over a period of 30 years, 1988–2017. Elevation, latitude and distance from moisture source have caused strong East–West and South–North gradients of precipitation across the territory of Iran so that the average annual precipitation increases from 55 mm in the eastern and central regions to 1,730 mm in the south-west coast of the Caspian Sea. Hierarchical cluster analysis identified six precipitation regions in Iran, including the arid, semi-arid, moderate, semi-humid, humid, and high humid regions. An investigation of the standardized precipitation index (SPI) showed that the trend in about 19 per cent of stations was significantly decreasing. It was non-significantly decreasing in 65 per cent, significantly increasing in less than 1 per cent, and non-significantly increasing in 15 per cent of the stations. While the occurrence of drought has increased in most parts of Iran, it has decreased in some stations only in the northern strip of the country. The line slope in more than 84 per cent of the stations represent negative values in SPI, which confirms an increase in the occurrence of droughts in Iran.


Abarghouei, H.B., Zarch, M.A.A., Dastorani, M.T.,Kousari, M.R. and Zarch, M.S. 2011. The survey of climatic drought trend in Iran. Stochastic Environmental Research and Risk Assessment 25 (6): 851-853.

Ahmadi, M., Salimi, S., Hosseini, S.A., Poorantiyosh, H. and Bayat, A. 2019. Iran's precipitation analysis using synoptic modelling of major teleconnection forces (MTF). Dynamics of Atmospheres and Oceans 85. 41-56.

Aliabad, F.A. and Shojaei, S. 2019. The impact of drought and decline in groundwater levels on the spread of sand dunes in the plain in Iran. Sustainable Water Resources Management 5. (2): 541-555.

Amirataee, B. and Montaseri, M. 2017. The performance of SPI and PNPI in analyzing the spatial and temporal trend of dry and wet periods over Iran. Natural Hazards 86. (1): 89-106.

Bahrami, M., Bazrkar, S. and Zarei, A.R. 2019. Modelling, prediction and trend assessment of drought in Iran using standardized precipitation index. Journal of Water and Climate Change 10. (1): 181-196.

Dai, A. 2011. Drought under global warming: a review. Wiley Interdisciplinary Reviews. Climate Change 2. (1): 45-65.

Dai, A., Zhao, T. and Chen, J. 2018. Climate change and drought: a precipitation and evaporation perspective. Current Climate Change Report 4. 301-312.

Daneshmand, H. and Mahmoudi, P. 2017. Estimation and assessment of temporal stability of periodicities of droughts in Iran. Water Resources Management 31. (11): 3413-3426.

Daneshvar, M.R.M., Bagherzadeh, A. and Khosravi, M. 2013. Assessment of drought hazard impact on wheat cultivation using standardized precipitation index in Iran. Arabian Journal of Geosciences 6. (11): 4463-4473.

Darijani, F., Veisi, H., Liaghati, H., Nazari, M.R. and Khoshbakht, K. 2019. Assessment of resilience of pistachio agroecosystems in Rafsanjan Plain in Iran. Sustainability 11. (6): 1656.

Dashtpagerdi, M.M., Kousari, M.R., Vagharfard, H., Ghonchepour, D., Hosseini, M.E. and Ahani, H. 2015. An investigation of drought magnitude trend during 1975-2005 in arid and semi-arid regions of Iran. Environmental Earth Sciences 73. (3): 1231-1244.

Degirmendžić, J. and Kożuchowski, K. 2017. Mediterranean cyclones, the atmospheric moisture content and precipitation in Poland. Geographia Polonica 901. 5-20.

Fazel, N., Berndtsson, R., Uvo, C.B., Madani, K. and Kløve, B. 2018. Regionalization of precipitation characteristics in Iran's Lake Urmia basin. Theoretical and Applied Climatology 132. (1-2): 363-373.

Ghaedi, S. 2019. The variability and trends of monthly maximum wind speed over Iran. IDŐJÁRÁS 4. 521-534.

Ghaedi, S. and Shojaiean, A. 2020. Spatial and temporal variability of precipitation concentration in Iran. Geographica Pannonica 244. 244-251.

Ghaedi, S. 2021. Underground spaces: a step towards sustainable development in Khuzestan Province, Iran. Problemy Ekorozwoju 16. (1): 193-200.

Gulácsi, A. and Kovács, F. 2018. Drought monitoring of forest vegetation using MODIS-based normalized difference drought index in Hungary. Hungarian Geographical Bulletin 67. (1): 29-42.

Hao, Z. and Singh, V.P. 2015. Drought characterization from a multivariate perspective: a review. Journal of Hydrology 527. 668-678.

Khajeh, S., Paimozd, S. and Moghaddasi, M. 2017. Assessing the impact of climate changes on hydrological drought based on reservoir performance indices case study: Zayandeh Rud River basin, Iran. Water Resources Management 319. 2595-2610.

Khoshakhlagh, F., Shakouri Katigari, A., Hadinejad Saboori, S., Farid Mojtahedi, N., Momen Poor, F. and Asadi Oskuee, E. 2016. Trend of the Caspian Sea surface temperature changes. Natural Environment Change 2. (1): 57-66.

Lengyel, A. and Botta‐Dukát, Z. 2019. Silhouette width using generalized mean - A flexible method for assessing clustering efficiency. Ecology and Evolution 9. (23): 13231-13243.

McKee, T.B., Doesken, N.J. and Kleist, J. 1993. The relationship of drought frequency and duration to time scales. Applied Climatology 17. (22): 179-183.

Modarres, R., Sarhadi, A. and Burn, D.H. 2016. Changes of extreme drought and flood events in Iran. Global and Planetary Change 144. 67-81.

Moghbeli, A., Delbari, M. and Amiri, M. 2020. Application of a standardized precipitation index for mapping drought severity in an arid climate region, south-eastern Iran. Arabian Journal of Geosciences 13. (5): 1-16.

Najafi, M.R. and Moazami, S. 2016. Trends in total precipitation and magnitude-frequency of extreme precipitation in Iran, 1969-2009. International Journal of Climatology 36. (4): 1863-1872.

Nouri, M. and Homaee, M. 2020. Drought trend, frequency and extremity across a wide range of climates over Iran. Meteorological Applications 27. (2): e1899.

Rostamian, R., Eslamian, S. and Farzaneh, M.R. 2013. Application of standardized precipitation index for predicting meteorological drought intensity in Beheshtabad watershed, central Iran. International Journal of Hydrology Science and Technology 3. (1): 63-76.

Sharafi, L., Zarafshani, K., Keshavarz, M., Azadi, H. and van Passel, S. 2020. Drought risk assessment: towards drought early warning system and sustainable environment in western Iran. Ecological Indicators 114. (106276): 1-12.

Some'e, B.S., Ezani, A. and Tabari, H. 2012. Spatiotemporal trends and change point of precipitation in Iran. Atmospheric Research 113. 1-12.

Somorowska, U. 2017. Soil water storage in Poland over the years 2000-2015 in response to precipitation variability as retrieved from GLDAS Noah simulations. Geographia Polonica 90. (1): 53-64.

Szabó, S., Szopos, N.M., Bertalan-Balázs, B., László, E., Milošević, D.D., Conoscenti, C. and Lázár, I. 2019. Geospatial analysis of drought tendencies in the Carpathians as reflected in a 50-year time series. Hungarian Geographical Bulletin 68. (3): 269-282.

Tabari, H., Abghari, H. and Hosseinzadeh Talaee, P. 2012. Temporal trends and spatial characteristics of drought and rainfall in arid and semi-arid regions of Iran. Hydrological Processes 26. (22): 3351-3361.

Zarei, A.R., Moghimi, M.M. and Mahmoudi, M.R. 2016. Analysis of changes in spatial pattern of drought using RDI index in south of Iran. Water Resources Management 30. (11): 3723-3743.

Zarei, A.R. 2018. Evaluation of drought condition in arid and semi-arid regions, using RDI index. Water Resources Management 32. 1689-1711.

Zarei, A.R. and Masoudi, M. 2019. Trend assessment of climate changes in Iran. EQA-International Journal of Environmental Quality 34. 1-16.

How to Cite
GhaediS. (2021). Anomalies of precipitation and drought in objectively derived climate regions of Iran. Hungarian Geographical Bulletin, 70(2), 163-174.
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