The potential influence of drains on the recent sediment characteristics and sedimentation rates of Lake Qarun, Western Desert, Egypt

In recent decades, Lake Qarun significantly suffered from the adverse effects of climate change (e.g., high evaporation rate) and human activities (e.g., industrial and agricultural development within the catchment). The objectives of this work were to (i) evaluate the sediment characteristics due to the impact of the catchment on the lake and (ii) estimate the sedimentation rates and relate these to historical changes in sediment. Three sediment Cores collected in 2018 from Lake Qarun were sliced into 5 cm intervals, and the radionuclides Pb-210 and Cs-137 were measured using a & gamma; spectrometer. The best validated models were the constant rate of supply (CRS) and the correct CRS(C-CRS). The results provide evidence that grain size, sediment fractions, organic matter (OM), organic carbon (OC) and sedimentation rate are all significantly influenced by agricultural and industrial activities.The geochronology models of Pb-210 indicated changes in the sedimentation process of Lake Qarun for 100 years that could be a vital source of information regarding changes in the regional and global hydrology. The estimated mean sedimentation rate based on the Pb-210 model is 0.45 & PLUSMN; 0.1 cm yr(-1) that extremely close to the sedimentation rate of the Cs-137 marker is 0.55 cm yr(-1) that indicates an excellent agreement in terms of sedimentation rate.

Automated summary

This study aims to evaluate the sediment characteristics and estimate sedimentation rates of Lake Qarun due to the impact of the catchment. The results indicate that agricultural and industrial activities significantly influence grain size, sediment fractions, organic matter, and sedimentation rate.