Recent hydrological variability of the Moroccan Middle Atlas Mountains inferred from microscale sedimentological and geochemical analyses of lake sediments

2019

Article référencé dans le Web of Science WOS:000488837500027

Jouve G., Vidal L., Adallal R., Rhoujjati A., Benkaddour A., Chapron E., Tachikawa K., Bard E., Courp T., Dezileau L., Hebert B., Rapuc W., Simonneau A., Sonzogni C., Sylvestre Florence

Quaternary Research, 2019, 91 (1), p. 414-430 ISSN 0033-5894

Study of the hydro-sedimentary dynamics of lakes provides key information on hydrological changes. In this work, we investigate Lake Azigza in the Moroccan Middle Atlas, a region that suffers from a scarcity of observational hydrological data necessary for a coherent management of water resources. Sedimentary deposits of Lake Azigza (32 degrees 58 ' N, 5 degrees 26 ' W, 1,550 m above sea level) were dated and analyzed by combining geochemical and mineralogical measurements coupled with microfacies characterization for the last 134 yr. The detrital component derived from X-ray fluorescence elemental composition and microstructures analysis of the lake sediments provided proxies of runoff activity and lake-level changes, respectively. These proxies were calibrated with regional hydro-climatic and instrumental measurements available over the last 50 yr and used to reconstruct past hydrological changes on inter-annual to decadal time scales between 1879 and 2013. Since 1879, lake level and runoff proxies responded in phase to regional inter-annual precipitation variations. We also show that after the major lake-level drop observed in 2008, the response of the runoff proxy to variable precipitation regime is enhanced. Such an approach emphasizes the potential of these hydro-climate-sensitive sedimentary archives to assess the impact of climate change in the Mediterranean region.

Limnologie physique / Océanographie physique [032] ; Hydrologie [062]

MAROC

Fonds IRD [F B010077083]

fdi:010077083