A long-term dataset on hydrology and suspended sediments in the Kamech catchment from the OMERE Observatory

Abstract. The Mediterranean region is characterized by a highly variable climate marked by prolonged dry spell interspersed with intense rainfall events mainly in autumn. These climatic extremes exacerbate droughts, flash floods and soil erosion, resulting in significant environmental and agricultural challenges across Mediterranean catchments. The dynamics of water and sediment fluxes in these environments are the result of complex interactions between climate, land use and management. Understanding these dynamics is crucial for recommending effective management strategies to mitigate erosion and runoff impacts. However, high-frequency datasets for both hydrology and sediment fluxes are often lacking for small Mediterranean catchments in North Africa, thus rendering these processes poorly understood.

In this context, the Kamech Critical Zone Observatory was established in 2004 to document high-frequency rainfall, discharge, and sediment fluxes across the 2.63 km² Kamech catchment in Cape Bon, Tunisia, which is dominated by Vertisols. The monitoring system comprises four nested hydrological stations, ranging in scale from the plot to the outlet of the catchment area. The longest time series covers almost 30 years. This article synthesizes the datasets of the observatory related to evaporation, rainfall, discharge and suspended sediment concentration. It describes the methodologies used to collect and process the data, including procedures for assessing data quality. It also suggests additional synthetic time series to facilitate subsequent hydrological analysis. Finally, it presents some preliminary explorations of the datasets and it suggests avenues for further studies. All datasets referenced in this work are openly accessible via the repository: https://doi.org/10.23708/PPPPDL (Raclot and Hamdi, 2025).