A Multi-Sensor Remote Sensing Framework to Track Agricultural Drought in the Souss-Massa Basin, Morocco

Agricultural drought is a growing concern in Morocco, especially in the Souss-Massa basin, where the economy is heavily reliant on increasingly limited water resources. As climate As climate variability intensifies and groundwater levels decline, traditional drought monitoring tools (mainly based on rainfall alone) no longer provide a comprehensive representation of the evolution of water stress in crops and soils. Based on remote sensing, we developed a framework to facilitate understanding of these intricate interactions.

We combine four satellite indicators to reflect different aspects of drought stress: vegetation greenness (VCI), land surface temperature (TCI), soil moisture availability (SMCI), and photosynthetic activity (GPP anomaly). These datasets, derived from MODIS and ESA-CCI products, were processed into a consistent time series from 2000 to 2023. Utilising the seasonal Standardized Precipitation Evapotranspiration Index (SPEI-6) as a reference, we trained a Random Forest model to generate a Remote Sensing Drought Index (RSDI) specifically tailored to the wheat-growing season in the Souss-Massa basin.

The developed index demonstrates robust performances across the region, effectively capturing both rapid shifts in meteorological conditions and the slower cumulative effects of water stress on vegetation.

The model exhibits strong predictive accuracy (R² ≈ 0.75) and remains stable even when applied to stations not utilized during the training process.

Importantly, the RSDI aligns closely with observed wheat yield anomalies (r ≈ 0.9), indicating its relevance for agricultural decision-making. The framework also reproduces major drought years, such as 2015–2016 and 2023–2024, revealing clear spatial contrasts linked to topography and irrigation patterns.

The combined use of multiple remote-sensing indicators provides a reliable measure of drought evolution and supports regional actors in planning and managing water and agricultural activities under growing climatic pressure.