Reservoir siltation and sediment characterization for reuse as construction material in a semi-arid area

Abstract

Anibi S, Ellouze S, Zairi M. 2024. Reservoir siltation and sediment characterization for reuse as construction material in a semi-arid area. Lake Reserv Manage. XX:XXX–XXX.

In this study, we investigated the siltation rate, evolution, and spatial distribution of sediments within the Siliana Dam reservoir, north-west Tunisia. We analyzed the geotechnical, chemical, mineralogical, and trace metal content properties of sediment samples collected from the reservoir. Additionally, we examined the potential valorization of reservoir sediments in road construction and the effects of hydrated lime treatment on their bearing characteristics. The Siliana dam reservoir is currently 50% silted up, and the sedimentation rate is approximately 1.52% per year. The sediments are mainly fine-grained, low organic with medium to high plasticity and high content of calcium carbonate. The sediments consist of calcite and quartz, with minor amounts of dolomite, hematite, and phyllosilicate minerals. Chromium, zinc, and copper contents in the sediments exceed environmental standards. The lime treatment improved the materials bearing capacity. Adding lime (5% by weight) resulted in an immediate bearing ratio of 26%, a higher ratio compared to the raw sediments. The study of the spatial and temporal evolution of sediment accumulation provides information to develop strategies for mitigating the accumulation of sediments. The sediment characterization evaluated the suitability of sediments to be used as construction materials, offering potential cost savings and contributing to informed decision-making for reservoir management.

Keywords:

• Reservoir siltation
• laboratory tests
• sediment characterization
• valorization
• Siliana Dam

Acknowledgments

We would like to express our gratitude to the staff of the Direction des Barrages et des Grands Travaux Hydrauliques, and the staff of the Direction du barrage Siliana, for their precious assistance and provision of necessary data. We also extend our appreciation to the laboratories of ESIM, ENSIT, the Faculté de Science de Bizerte, Centre des Recherches et des Technologies des Eaux (CERTE), and the Direction du sol, for their help in conducting the experimental tests.

Disclosure statement

The authors declare that they have no competing interest.