a Spatial maps of DSI from 2001 to 2015. b Spatial maps of DSI from 2016 to 2019

a Spatial maps of DSI from 2001 to 2015. b Spatial maps of DSI from 2016 to 2019

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Unlike most disasters, drought does not appear abruptly. It slowly builds over time due to the changes in different environmental and climatological factors. It is one of the deadly disasters that has plagued almost every region of the globe since early civilization. Droughts are scientifically being studied with the help of either simple or compos...

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... With the unprecedented volume of different remote sensing datasets, the shift from ground-based observations to satellite-based sensors provides near real-time measurements, global coverage, and consistent and improved spatial resolution data records for the monitoring of droughts from a wide array of perspectives, such as agricultural and meteorological droughts [31,32]. In addition, the launch of Google Earth Engine (GEE), a big data cloud-based processing platform, in 2010 enabled users to access vast satellite datasets, and makes it possible to process such data for drought characterization and assessment [33][34][35][36][37]. Apart from the repeated observation capacity of the land surface, remote sensing sensors can provide measurements in regions that are either inaccessible or lack in-situ monitoring facilities for drought assessment [30]. ...
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... In other words, Iran has been confronted not only with a shortage but also with an unequal geographical distribution of precipitation. The increasing trend in drought years' frequency and the decreasing trend in precipitation amount can also be observed in different parts of the world, including the middle latitudes of the Northern Hemisphere (Adler et al. 2017), Asia, Africa, and Australia (Khan and Gilani 2021), northern Ethiopia (Asfaw et al. 2017), Sardinia, Italy (Caloiero et al. 2019), Cauca River, southwestern Columbia (Ávila et al. 2019), Aegean, and western Turkey (Bacanli 2017). The increasing trend in global warming has played an important role in the changes in elements and the occurrence of extreme climatic phenomena over different parts of Iran (Alizadeh et al. 2010;Karimi et al. 2018;Daneshvar et al. 2019). ...
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