Rheraya watershed already suffers from the impacts of climate variability and will be further affected by climate change. Severe water shortages and extremely fragile ecological conditions necessitate careful attention to water resources management. The aim of this study is to analyze Rheraya's future water situation under different scenarios of socio-economic development and climate change until 2100. The Water Evaluation and Planning System model (WEAP) has been applied to estimate the current water demands and the increased water demands resulting from climate change. WEAP was calibrated using meteorological and demand observations, then, updated with present-day and future climatic conditions using the Statistical Down-scaling Model with two projections (A2, B2) of the Intergovernmental Panel on Climate Change. Those projections show an increase in temperature of about 2-3 °C and a reduction in precipitation of 40-60% with respect to baseline. The results show that the pressure on Rheraya's water resources will increase, leading to greater competition for surface water, and that domestic, tourist, OPEN ACCESSWater 2012, 4 29 livestock and agricultural demands will not be met by the year 2100. The Results also demonstrate that the assessments of adaptation strategies proposed by decision makers are effective but not sustainable for the watershed.

This work analyzes satellite and socioeconomic data to explore the relationship between food and wood demand and supply, expressed in terms of net primary production (NPP), in Morocco. A vulnerability index is defined as the ratio of demand to supply as influenced by population, affluence, technology and climate indicators. The present situation (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007), as well as projections of demand and supply, following the Intergovernmental Panel on Climate Change, Scenarios A2 and B2, are analyzed for a 2025 horizon. We find that the food NPP demand increased by 34.5%, whereas the wood consumption NPP demand decreased by 19.3% between 1995 and 2007. The annual NPP required to support the population's food and wood appropriation was 29.73 million tons of carbon (MTC) in 2007, while the landscape NPP production for the same year was 60.24 MTC; indicating that the population appropriates about 50% of the total NPP resources. Both scenarios show increases in demand and decreases in supply. Under A2, it would take more than 1.25 years for terrestrial ecosystems in Morocco to produce the NPP appropriated by populations in one year. This number is 0.70 years under B2. This already high vulnerability for food and wood products is likely to be exacerbated with climate changes and population increase.