Jean Albergel

The Mediterranean region is characterized by a highly variable climate marked by prolonged dry spell interspersed with intense rainfall events mainly in autumn. Understanding the dynamics of water and sediment fluxes in this climatic context 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 km ² Kamech catchment in Cape Bon, Tunisia. The landscape is characterised by hilly terrain, and the soil type is dominated by Vertisols, which crack for approximately half of the year. This catchment's land is mainly used to cultivate annual cereals and leguminous crops. The monitoring system comprises four nested hydrological stations, ranging in scale from a 1.3 ha plot to the outlet of the 263 ha 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 homogenized 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).

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).

Under climate change conditions, optimizing water resources management in rainfed agricultural production systems requires the reasonable choice of crops. In this context, the adoption of crops diversification is promoted to increase the agricultural production and the added value per cubic meter of rain water (green water) used by crops. Contributing, therefore, to increase agricultural production and to preserve soil and water resources. The objective of this study is: (i) to identify mixed crops within agricultural fields and, (ii) to evaluate the biomass production and the water productivity in the Lebna watershed (Cap-Bon, Tunisia) using remote sensing and field measurements. The study area, covering 210 km², is characterized by the predominant of cereals, legumes and fodder cropping systems. The experiments allowed the quantification of crop evapotranspiration and the observed biomass production at the agricultural field plots. The use of the sentinel images and the observations at different agricultural fields allowed to produce NDVI maps. The results first confirmed a good correlation between biomass production and NDVI values. The exponential relationships showed a values of R² greater than 0.7. The use of sentinel images and GIS allowed to compute water productivity from field to watershed scale. The results revealed a considerable spatial variation in water productivity values for different crops. Compared to a single crop, the cereal-legume mixture cropping improved the water productivity. The maximum value with 9.07 kg m⁻³ is observed for the mixture crops. The lowest value (0.12 to 2.40 kg m⁻³) was obtained for the cereal crop. These results help to recommend adaptation measures in agricultural production systems to climate change.

In the Ferkla Oasis, much like in numerous other oases across the southeastern region of Morocco, a range of socio-economic and environmental challenges are intricately linked to the inadequate management of water resources. One proposed remedy to address these concerns is the implementation of...

The provided paper offers a comprehensive overview of the intricate relationship between water and energy resources, focusing on their interdependence and the challenges posed by climate change. It highlights the crucial need for integrated approache...

Hydropower is the world’s largest and most widely used renewable energy source. It is expected that climate and land use changes, as well as hydraulic engineering measures, will have profound impacts on future hydropower potential. In this study, the hydropower potential of the Bafing watershed was estimated for the near future (P1: 2035–2065) and the far future (P2: 2065–2095). For this purpose, the moderate scenario ssp 126 and the medium–high scenario ssp 370 were used to explore possible climate impacts. In three management scenarios, we tested the interaction of the existing Manantali Dam with two planned dams (Koukoutamba and Boureya) using an ecohydrological water management model. The results show that, under ssp 126, a 6% increase in annual river flow would result in a 3% increase in hydropower potential in the near future compared with the historical period of 1984–2014. In the far future, the annual river flow would decrease by 6%, resulting in an 8% decrease in hydropower potential. Under ssp 370, the hydropower potential would decrease by 0.7% and 14% in the near and far future, respectively. The investment in the planned dams has benefits, such as an increase in hydropower potential and improved flood protection. However, the dams will be negatively affected by climate change in the future (except in the near future (P1) under ssp 126), and their operation will result in hydropower potential losses of about 11% at the Manantali Dam. Therefore, to mitigate the effects of climate change and adjust the operation of the three dams, it is essential to develop new adaptation measures through an optimization program or an energy mix combining hydro, solar, and wind power.

This communication is dedicated to the Mediterranean agro-hydrological observatory OMERE (Mediterranean Observatory of Rural Environment and Water). It aims to explain the observation strategy and to highlight how this strategy and the associated research have contributed to a better understanding of the impact of agricultural and land management on water and soil resources in Mediterranean catchments. OMERE is a Franco-Tunisian observatory based on two agricultural catchments, one in northern Tunisia and the other in southern France, representing the diversity of agricultural and ecosystem situations in hilly Mediterranean regions. The observatory was created more than twenty years ago to answer key scientific questions concerning the impact of global changes on soil and water resources (Voltz and Albergel, 2002). More specifically, the motivation has been to study how hydrological processes involved in water cycles and in the mass transport, such as contaminants and sediments, are affected by changes in farming practices and landscape management . The processes underlying these changes may be slow, such as in land use or contaminant dynamics, or infrequent over time, such as erosion. Understanding these processes and their relationship requires long-term observations to capture slow dynamics or infrequent events, which motivated the OMERE observatory. The OMERE observatory belongs to the French national network OZCAR, dedicated to the observation of the critical zone. The observation strategy is motivated by monitoring the flow of water, sediments and contaminants and hydrological and climatic variables at different spatial scales from cultivated plots and landscape elements to the catchment scale (Molénat et al., 2018). These measurements were made with fine temporal resolution on a long-term scale and examining land use, agricultural practices and soil surface characteristics. The long-term observation strategy aims to support multidisciplinary integrative research to elucidate the conditions that improve soil and water management and the provision of ecosystem services in the Mediterranean context of rain-fed agriculture. The observatory helped to address three scientific questions: (i) better understand water flows, erosion and contaminants, in particular pesticides, and their natural and anthropogenic factors in the short and long term; (ii) analyze the overall effects of agriculture and land management on mass flows at different scales, from the plot to the watershed or the landscape; and (iii) develop new scenarios for sustainable agricultural management and better delivery of ecosystem services. Some of the main scientific advances of research conducted using the observatory obtained through OMERE are presented. The main perspectives in matter of the observation strategy are also drawn. References Molénat, J., Raclot, D., Zitouna R., ...., Albergel, J., and Voltz M., 2018, OMERE: A Long-Term Observatory of Soil and Water Resources, in Interaction with Agricultural and Land Management in Mediterranean Hilly Catchments, Vadose Zone J., 17:180086. doi:10.2136/vzj2018.04.0086 Voltz, M., and A. Albergel. 2002. OMERE: Observatoire Méditerranéen de l’Environnement Rural et de l’Eau- Impact des actions anthropiques sur les transferts de masse dans les hydrosystèmes méditerranéens ruraux. Proposition d’Observatoire de Recherche en Environnement. Minist. Français Rech., Paris more information at : www.obs-omere.org

Under climate change conditions, optimizing water resources management in rainfed agricultural production systerms requires the reasonable choice of crops. In this context, the adoption of crops diversification is promoted to increase the agricultural production and the added value per cubic meter of rain water (green water) used by crops. Contributing, therefore, to increase agricultural production and to preserve soil and water resources. The objective of this study is : i) to identify mixed crops within agricultural fields and, ii) to evaluate the biomass production and the water productivity in the Lebna watershed (Cap-Bon, Tunisia) using remote sensing and field measurements. The study area, covering 210 km2, is characterized by a semi-arid Mediterranean climate, the predominant of cereals, legumes and fodder cropping systems, and the degradation of soil resources. The field investigation and experiments allowed the quantification of crop evapotranspiration and the observed biomass production at the agricultural field plots. The use of the sentinel images and the observations at different agricultural fields allowed to produce NDVI maps. The results first confirmed a good correlation between biomass production and NDVI vlaues. The linear relationships showed a values of R² greater than 0.9 and  values of RMSE less than 0.35. The use of sentinel images and GIS allowed to compute water productivity from field to watershed scale.  The results revealed a considerable spatial variation in water productivity values  for different crops. Compared to a single crops, the cereal-legume mixture cropping improved the water productivity. Theses results help to recommed adaptation measures in agricultural production systems to climate change. Ongoing work coupling field experiments, remote sensing and agro-hydrological model aim to develop simulation and evaluate the agri-environmental impacts from field to regional scale.