Three-decade assessment of dry and wet spells change across Iran, a fingerprint of climate change

Abstract

Extended periods of hydro-climate extremes with excessive or scarce rainfall associated with high or low temperatures have resulted in an imbalanced water cycle and inefficient socio-economic systems in several regions of Iran. However, there is a lack of comprehensive investigations on short-term to long-term variations in timing, duration, and temperature of wet/dry spells. This study bridges the current gap through a comprehensive statistical analysis of historical climatic data (1959–2018). Results indicated that the negative tendency of the accumulated rainfall (− 0.16/ − 0.35 mm/year during the past 60/30 years) in 2- to 6-day wet spells had made significant contributions to the ongoing downward trend in annual rainfall (− 0.5/ − 1.5 mm/year during the past 60/30 years) owing to a warmer climate condition. Warmer wet spells are likely responsible for precipitation patterns changes in snow-dominated stations since their wet spells temperature has more than threefold growth with increasing distance to coasts. The most detected trends in climatic patterns have started in the last two decades and become more severe from 2009 to 2018. Our results confirm the alteration of precipitation features across Iran due to anthropogenic climatic change, and suggest expected increase in air temperature would likely result in further dry and warm conditions over the coming decades.

Heatwave Duration and Heating Rate in a Non‐Stationary Climate: Spatiotemporal Pattern and Key Drivers

“…It is worth mentioning that the heatwaves odds experienced insignificant (P value > 0.05) changes for 23% of stations, including Abadan, Arak, Birjand, Urmia, Zahedan, and Zanjan. Other studies confirmed similar positive tendencies in heatwaves characteristics, summer temperature, and maximum dry spell temperature in different regions around the world (Basha et al, 2017;Deng et al, 2018;He et al, 2022;Jamali et al, 2022;Jyoteeshkumar Reddy et al, 2021;Motamedi et al, 2023;Sato & Nakamura, 2019;Trancoso et al, 2020).…”

“…Over the past decades, numerous studies have indicated that climatic records exhibit some non‐stationarity characterized by trends and shifts (Gohari et al., 2022; Jamali et al., 2022; Motamedi et al., 2023; Rougé et al., 2013; Ruibal‐Conti et al., 2013; Wagesho et al., 2012; Y. Wang et al., 2021). Several approaches, such as frequency analysis with time‐varying distribution functions, have been proposed to tackle non‐stationarity in hydrometeorological and climatological extremes (Ju et al., 2021; Lee et al., 2020; Ouarda et al., 2019; Ragno et al., 2019; Sarhadi & Soulis, 2017; Sun et al., 2022; Vinnarasi & Dhanya, 2022; Vu & Mishra, 2019).…”

A Social Dimension of Adaptation and Mitigation of Climate Change: Empowering Local Rural Communities to Confront Extreme Poverty

“…Drylands in Iran are likely to be affected more adversely than other countries in the Middle East [10], with predictions of increasing frequency and duration of extremely dry periods and extremely hot days [11]. These trends have already been identified in climatic records when comparing the two 30-year periods between 1959 and 2018 [12]. Since 1970 in the arid rangelands of Khorasan (southeastern Iran), annual rainfall variability has increased along with a rising precipitation index, indicating greater risk of droughts and intense rainfalls [13].…”

Stability of Agronomic Traits of Barley Evolutionary Populations under Drought Conditions in Iran

“…Iran is particularly vulnerable to climate change because about 33.5% of its agricultural land (6.2 million hectares) is rainfed, and 76% of the rainfed area receives less than 400 mm of annual rainfall [8]. Iran is expected to experience an increase of 2.6 • C in mean temperatures and a 35% decline in precipitation in the next several decades [9] and there is evidence of a downward trend in precipitation in recent decades [10][11][12]; therefore, there is a need to increase the resilience of crops to reduce the effect of the frequent intensive dry episodes [13].…”