Drought trends projection under future climate change scenarios for Iran region

duration of dry periods in warmer climates is longer than colder climates. Moreover, the tem- poral distribution of precipitation and potential evapotranspiration indicated that in a large number of stations, there is a significant difference between them in the middle months of the year, which justifies the importance of prudent water management in warm months. 1. Introduction Drought as one of the natural disasters has enormous socio-economic consequences all over the world. Its long-lasting effects on agriculture, the ecosystem, and the economy over broad regions have been reported in several investigations [1, 2]. Since determining the exact dates of the beginnings and endings of droughts is never possible, estimating the effects and losses of drought is difficult. Furthermore, droughts could cause or accentuate other dangerous events such as floods, storms, and hurricanes [3]. This expensive phenomenon is driven by a variety of unpredictable factors which in turn enhances the complexity of this poorly understood phe- nomenon [4, 5]. On the other hand, climate change as a reaction of nature to human activities is projected will likely increase in the future due to the global warming effect, which deterio- rates water shortage and threatens human lives and livelihoods [6]. Accordingly, climate change influences the ecosystem in terms of changing precipitation patterns and air tempera- tures, which may cause acute droughts. In the presented work [7], climate change would inten-

sify natural disasters such as drought or flood. These consequences are visible in either short- term or long-term processes [8, 9]. Given that, identifying, and discovering changes in drought and finding their culprits are complicated. Moreover, high spatial and temporal variability of drought conditions results in uncertainty in forecasting drought. These circumstances necessitate the study of this natural phenomenon in every area which has been done in several investigations [10]. The climate change effect evaluation conducted on meteorological drought indices including Standard pre- cipitation index (SPI) and Standardized precipitation-evapotranspiration index (SPEI) in Var- amin plain [11]. Kamali and Asghari (2023) investigated the impact of future drought events under climate change conditions on groundwater storage in Najafabad aquifer in Iran [12]. Muthuvel et al. (2023) assessed global concurrent drought traits and their effects on maize yield under climate change in the USA, China, Brazil, Mexico, Argentina, France, and India [13]. The impacts of climate warming on the future hydrological droughts employed in 6,688 catchments by Gu et al. [14], and revealed that precipitation stress controls the development of historical droughts over *87% of global catchments. Predictability of meteorological drought in the semi-arid region based on the standardized precipitation index (SPI) was investigated by Elbeltagi, et al. [15]. An evaluation established for the future drought in the west of Iran by

SPI under the A1B, B1 and A2 emission scenario of HadCM3 for the period 2011–2030 [10]. The result of their study indicated that the severity of drought will increase with longer return period. Quantifying the effect of climate change on characteristics of drought in Australia, Bra- zil, China, Ethiopia, India, Spain, Portugal and the USA showed that adaptation to drought risk will be vital in these regions for the first half of the twenty-first century [16]. Assessing fea- tures of future drought conditions over South Korea by [17] demonstrated an increase of 6% in frequency and severity of drought during the dry season. In the presented work [18], the authors investigated drought risk under climate and land use changes in the Frome catchment in the UK. In this survey, the drought indices predicted an increase in the severity of future drought events under the high emission scenarios. The study of [19] revealed an increasing PLOS ONE Drought trends projection under future climate change scenarios for Iran region PLOS ONE | https://doi.org/10.1371/journal.pone.0290698 November 9, 2023 2 / 24