A new precipitation dataset is provided since 2014 by the Global Precipitation Measurement (GPM) satellite constellation measurements combined in the Integrated Multi-satellite Retrievals for GPM (IMERG) algorithm. This recent GPM-IMERG dataset provides potentially useful precipitation data for regions with a low density of rain gauges. The main objective of this study is to evaluate the accuracy of the near real-time product (IMERG-E) compared to observed rainfall and its suitability for hydrological modeling over a mountainous watershed in Morocco, the Ghdat located upstream the city of Marrakech. Several statistical indices have been computed and a hydrological model has been driven with IMERG-E rainfall to estimate its suitability to simulate floods during the period from 2011 to 2018. The following results were obtained: (1) Compared to the rain gauge data, satellite precipitation data overestimates rainfall amounts with a relative bias of +35.61% (2) In terms of the precipitation detection capability, the IMERG-E performs better at reproducing the different precipitation statistics at the catchment scale, rather than at the pixel scale (3) The flood events can be simulated with the hydrological model using both the observed and the IMERG-E satellite precipitation data with a Nash–Sutcliffe efficiency coefficient of 0.58 and 0.71, respectively. The results of this study indicate that the GPM-IMERG-E precipitation estimates can be used for flood modeling in semi-arid regions such as Morocco and provide a valuable alternative to ground-based precipitation measurements.

This research aims at establishing an integrated modelling framework to assess the impact of climate change on water supply and demand across an arid area in the western Haouz plain in Morocco. Five general circulation models (GCMs) are used to evaluate the availability of future water resources under Representative Concentration Pathways (RCP4.5 and RCP8.5 emission scenarios). The projected crop water demand and irrigation water demand were analysed using the Aquacrop software, taking into account the impact of climate change on both reference evapotranspiration and crop cycle lengths. The future water balance is simulated by means of the Water Evaluation And Planning (WEAP) tool, including several socio-economic and land use scenarios under RCP4.5 and RCP8.5 scenarios. The results reveal an important decrease in net precipitation with an average of −36.2% and −50.5% under RCP4.5 and RCP8.5 scenarios, respectively. In terms of water balance, the ‘business as usual’ scenario would lead to an increasing unmet water demand of about +22% in the 2050 horizon and to an increased depletion of the water table that could reach 2 m/year. Changing water management and use practices remains the only solution to ensure sustainable water use and deal with the projected water scarcity.

Extreme climate events often have a significant and direct impact on social, economic, and environmental systems. This study is an attempt to characterize the current trends and future projections of extreme climatic indices in an arid region of Morocco on both an annual and a seasonal scale using 12 precipitation and temperature-based indices. The Mann–Kendall test was used to assess the trends, and the inverse distance weighted interpolation method was employed to analyze the spatial distribution of extreme precipitation indices. The results showed that the most extreme climate indices are spatially distributed with a clear gradient from the mountainous area toward the plains. Furthermore, the analysis indicates nonsignificant downward trends in the number of days with a rainfall amount greater than 10 or 20 mm. However, a significant negative trend in the consecutive dry days was observed at the Iloujdane and Sidi Bouathmane stations. The temperature indices have recorded statistically significant upward trends at all the stations. Finally, based on the RCP4.5 and RCP8.5 scenarios, future climate change simulations show, respectively, annual precipitation decreases of 23 and 34% and temperature increases of 1.9 and 2.8 °C, which could imply substantial losses of cereal yield in the rainfed agriculture.

Morocco has recently witnessed a surge in drought occurrences, leading to considerable socioeconomic damage. The standardized precipitation index (SPI) at three- and 12-month timescales was employed to assess spatiotemporal drought characteristics across the Marrakech-Safi arid region. Mann–Kendall and Sen's slope methods were adopted to assess SPI trends. Furthermore, the Gumbel copula was employed to construct the joint distribution function of three drought variables: duration, severity, and intensity. The spatial distribution of drought return period for different scenarios was carried out. Results revealed notable interannual fluctuations of wet and drought cycles, with the driest years being 1983 and 2005 and a mixture of positive and negative trends of SPI-12 and SPI-3 over the 1972–2018 period. Nevertheless, statistical significance was observed in only 50% of the SPI-12 trends and 27% of the SPI-3 trends. The drought severity in the region was highest in the plain area, with droughts lasting 6–20 months for 75% of all drought events for SPI-12. The coastal strip exhibited the lowest drought recurrences. Furthermore, dry periods exhibited greater temporal variability over shorter timescales. Finally, trivariate return periods of drought events were the longer, averaging 93 months for SPI-12.