Multiscale drought monitoring and comparison using remote sensing in a Mediterranean arid region: a case study from west-central Morocco

Assessment of Drought Indexes on Different Time Scales: A Case in Semiarid Mediterranean Grasslands

“…Our results suggest that spring and autumn, and particularly May and September, are the most correlated time frames throughout the year. Similar conclusions were drawn from the work [13] that obtained higher correlations in the crop growth period. In our case, spring, and autumn are the seasons when the NDVI reaches its peak.…”

“…As a result of the statistical techniques applied in SPI estimation, a probabilistic approach uses a z-score transformation to convert the precipitation probability density function as a distribution with mean zero and variance of one [9,10]. SPI has been successfully applied in tracking drought effects on irrigated areas [11], drought monitoring in semiarid regions [12,13] and studying climate change trends through historical rainfall data [14]. The Standardised Precipitation Evapotranspiration Index (SPEI) is presented as an improvement of the SPI index [10] and is another standard index for monitoring drought episodes.…”

Prospective analysis of spatial heterogeneity influence on the concordance of remote sensing drought indices: a case of semi-arid agrosystems in Morocco (Moulouya and Tensift watersheds)

“…In recent years, under the combined and cumulative effect of climatic and anthropogenic factors, they have become particularly sensitive to extreme climate variability (Malone et al 2016;Le Page and Zribi 2019;Fragaszy et al 2020). In the particular context of Mediterranean arid and semi-arid agroecosystems, drought is the most doubtful climatic hazard (Cook et al 2016;Ouatiki et al 2019;Fragaszy et al 2020;Meliho et al 2020;Hadri et al 2021). The unpredictable occurrence in time and space of drought sequences has serious socioeconomic and ecosystem consequences in regions heavily dependent on rainfall (Lui et al 2018;Sinha et al 2017;Cartwright et al 2020;Liu et al 2020;Liu et al 2016;Wu et al 2020;Jiao et al 2021).…”

“…In Morocco, in semi-arid agrosystems, such as the Tensift watershed as well as desert agrosystems, such as the eastern highlands, drought episodes have become more intense and more frequent on average 49% of dry years at Guenfouda station and 45% at Oujda station over the period from 1970 to 2016 (El Hafid et al 2017). These drought episodes have had significant impacts on the productivity of agrosystems (Hanad e et al 2020;Hadri et al 2021). In these agroecosystems, the response of natural and anthropogenic units to drought is controlled by many processes.…”

“…Nevertheless, it should be noted that depending on the variables taken into account, the time scale and the approach used, there are very often contradictory conclusions as to the spatial concordance of biophysical indices and their statistical relationships with in situ measurements (Bushra et al 2019;Li, He, et al 2020;Bento et al 2020;Han et al 2020;Wu et al 2020;Mahyou 2020;Hadri et al 2021). Many studies worldwide showed that spatial coherence, as well as correlations between drought indices, vary greatly depending on the specific characteristics off each area (Naumann et al 2014;Zhuo et al 2016;Bento et al 2018;Zhong et al 2019;Huang et al 2020;Han et al 2020;Wu et al 2020;Cartwright et al 2020;Son et al 2020).…”