Mediterranean water resources are under significant stress due to climate change, leading to reduced water availability, altered river regimes, and challenges in water management. Climate models predict increased temperatures and decreased precipitation by the end of the 21st century, which will exacerbate water stress, increase evapotranspiration, and alter the balance between evapotranspiration, runoff, and groundwater flow. This will result in reduced soil moisture, less frequent saturation, and changes in snow accumulation and melting, particularly in mid-mountain areas. Future land use changes, such as forest and shrub expansion in mountainous regions due to farmland abandonment, will further impact water availability. In lowlands, increasing water demand from agriculture, urbanization, and tourism will strain water resources. Future scenarios suggest a decline in average streamflow, more frequent and severe droughts, and changes in river regimes, including earlier spring high flows and more irregular winter discharges. Reservoir management will face challenges due to reduced snowmelt and increased sedimentation, reducing reservoir efficiency. Coastal areas will experience water scarcity, groundwater depletion, and saltwater intrusion, necessitating improved water management, pricing, and recycling policies. Climate change has led to a general decrease in precipitation across the Mediterranean, with some regions experiencing more intense droughts. Temperature has risen significantly, particularly in summer, affecting snowpack and water availability. Land cover changes, such as deforestation and afforestation, have altered hydrological processes, influencing evapotranspiration, soil moisture, and groundwater recharge. These changes are as significant as climate variability in explaining hydrological alterations. Land use changes, including farmland abandonment and reforestation, have altered water balance and runoff patterns. In the Mediterranean, farmland abandonment has led to shrub and forest expansion, increasing runoff and soil erosion. Urbanization and tourism have concentrated water demand in coastal areas, leading to land degradation and water scarcity. In southern Mediterranean countries, population growth and market expansion have increased pressure on natural resources, affecting plant cover and water availability. Changes in river discharge and water resources are influenced by precipitation, temperature, and land cover. Reduced precipitation and increased temperatures have led to lower river discharge, with significant declines in some regions. Snowmelt and reservoir management have also altered river regimes, with earlier snowmelt and reduced snowpack affecting water availability. Reservoir construction and management have reduced downstream flows, increasing drought severity and affecting water supply. Land cover changes, such as deforestation and afforestation, have significant hydrological impacts. In the Spanish Pyrenees, the expansion of shrubs and forests has increased runoff and erosion, affecting water availability. Changes in vegetation cover influence evapotranspiration, soil moisture, and groundwater recharge, altering the water balance and affecting water resources. These changes, combined with climate variability, are critical in determining the future availability and management of water resources in the Mediterranean region.Mediterranean water resources are under significant stress due to climate change, leading to reduced water availability, altered river regimes, and challenges in water management. Climate models predict increased temperatures and decreased precipitation by the end of the 21st century, which will exacerbate water stress, increase evapotranspiration, and alter the balance between evapotranspiration, runoff, and groundwater flow. This will result in reduced soil moisture, less frequent saturation, and changes in snow accumulation and melting, particularly in mid-mountain areas. Future land use changes, such as forest and shrub expansion in mountainous regions due to farmland abandonment, will further impact water availability. In lowlands, increasing water demand from agriculture, urbanization, and tourism will strain water resources. Future scenarios suggest a decline in average streamflow, more frequent and severe droughts, and changes in river regimes, including earlier spring high flows and more irregular winter discharges. Reservoir management will face challenges due to reduced snowmelt and increased sedimentation, reducing reservoir efficiency. Coastal areas will experience water scarcity, groundwater depletion, and saltwater intrusion, necessitating improved water management, pricing, and recycling policies. Climate change has led to a general decrease in precipitation across the Mediterranean, with some regions experiencing more intense droughts. Temperature has risen significantly, particularly in summer, affecting snowpack and water availability. Land cover changes, such as deforestation and afforestation, have altered hydrological processes, influencing evapotranspiration, soil moisture, and groundwater recharge. These changes are as significant as climate variability in explaining hydrological alterations. Land use changes, including farmland abandonment and reforestation, have altered water balance and runoff patterns. In the Mediterranean, farmland abandonment has led to shrub and forest expansion, increasing runoff and soil erosion. Urbanization and tourism have concentrated water demand in coastal areas, leading to land degradation and water scarcity. In southern Mediterranean countries, population growth and market expansion have increased pressure on natural resources, affecting plant cover and water availability. Changes in river discharge and water resources are influenced by precipitation, temperature, and land cover. Reduced precipitation and increased temperatures have led to lower river discharge, with significant declines in some regions. Snowmelt and reservoir management have also altered river regimes, with earlier snowmelt and reduced snowpack affecting water availability. Reservoir construction and management have reduced downstream flows, increasing drought severity and affecting water supply. Land cover changes, such as deforestation and afforestation, have significant hydrological impacts. In the Spanish Pyrenees, the expansion of shrubs and forests has increased runoff and erosion, affecting water availability. Changes in vegetation cover influence evapotranspiration, soil moisture, and groundwater recharge, altering the water balance and affecting water resources. These changes, combined with climate variability, are critical in determining the future availability and management of water resources in the Mediterranean region.