Spatio-temporal evolution of the surface dynamics and the underground water flow of the natural lake Tamda (Middle Atlas, Morocco)

Lake Tamda is a temporary endorheic lake located in the central Middle Atlas (Morocco) that exhibits pronounced seasonal filling and drying phases. This study aims to quantify the respective roles of climatic forcing and subsurface drainage in controlling the lake’s hydrological dynamics within a semi-arid mountain environment. We combine multi-temporal satellite observations (2011–2021) with field measurements, piezometric data, and rainfall records to track variations in lake surface area and groundwater response. Results show that lake expansion is strongly controlled by winter–spring precipitation and snowmelt, while rapid summer drawdown cannot be explained by evaporation alone. Instead, drainage through karstified carbonate bedrock and permeable zones within the landslide dam plays a major role in water loss, with structural lineaments aligning the lake with downstream wells and springs. During recent dry years (2019–2021), reduced rainfall and rising temperatures led to recurrent complete desiccation by late summer. These findings demonstrate that Lake Tamda functions as a precipitation-filled, fracture-drained seasonal lake highly sensitive to climate variability. The lake represents both a valuable geoheritage site and a vulnerable hydrosystem, highlighting the need for integrated hydrogeological monitoring to assess future impacts of climate change.