Nidal Salim, Walter Wildi Institute F.-A. Forel, University of Geneva, Switzerland Impact of global climate change on water resources in the Israeli, Jordanian and Palestinian region curriculum in natural environmental science, 2005

Regional map of North Africa and Meadle East curriculum in natural environmental science, 2005

1. Introduction and objectives. 2. Climate and variations in climate. 3. Water Resources. 4. Trend relation between climate change and water resources. 5. Impact 6. Vulnerability. 7. Conclusions and Results 8. Recommendations. Main Topics curriculum in natural environmental science, 2005

The study area is divided into three main geographical regions: 1.Coastal area 2.Mountain area 3. Desert area curriculum in natural environmental science, 2005

Schematic diagram of the Water Cycle, combination of climatic parameters and water resources curriculum in natural environmental science, 2005

Rainfall geographical distribution curriculum in natural environmental science, 2005

1. Coastal area 2. Mountain area. 3. Dessert Average monthly rainfall, potential evaporation, and average daily maximum and minimum temperatures for three different geographical regions curriculum in natural environmental science, 2005

Groundwater resources : the 20 basins curriculum in natural environmental science, 2005

Precipitation tends to be very seasonal; in the Middle East countries. Temperature shows a real increase trend Observed annual precipitation (top) and temperature (bottom) changes for the Middle East/Arid Asia region. curriculum in natural environmental science, 2005

4. Observed trend in climate 1. Precipitation: Trend to a decrease in some areas and an increase in others. Almost stable, combined with some features: markedly increased in intensity. Alpert et al. (2000) Increased frequency of extreme weather events increased seasonal variability due to a decrease in the (T max and T min, respectively). Shortened rainy season 2. Temperature: A spatial analysis shows warming (Ben-Gai et al. 1998a, 1999). 3. Evapotranspiration : a trend of decreasing was measured in the eastern Mediterranean. And a trend of increasing measured in the whole land area. curriculum in natural environmental science, 2005

The water level monitored continuously since Declined over 21 m from 1930 to Water Level of the Dead Sea curriculum in natural environmental science, 2005

Groundwater level trend ( ) – Mountain area Water level (m) curriculum in natural environmental science, 2005

Groundwater level trend ( ) – Desert area Water level (m) Water level (m) curriculum in natural environmental science, 2005

Changes in precipitation behavior attests to the sensitivity of systems to climate change in the following forms. 1.The increased rainfall intensity will increased surface run- off. 2.Increasing the frequencies and intensities of surface run- off events, causing: topsoil erosion and loss of water further loss of vegetation and higher run-off events Reduced infiltration rates which will also reduce aquifer recharge and water availability. curriculum in natural environmental science, 2005

3. Increased run-off, coupled with sea level rise lead to the creation of swamps and Salt water intrusion. 4. A decrease in the hydraulic slope between drainage systems (or streams) and sea level reduces the efficiency of water transfer and increases the probability of flooding. 5. changes in land use and vegetation significantly reduces the permeability of the underlying soil. Arid region could experience large decrease in runoff of up to 40% in some basins. Changes in precipitation behavior attests to the sensitivity of systems to climate change in the following forms (continued): curriculum in natural environmental science, 2005

Source and use of water curriculum in natural environmental science, 2005

Source and use of water curriculum in natural environmental science, 2005

Source and use of water curriculum in natural environmental science, 2005

 Traditionally, water resources systems are designed on the assumption that the statistical characteristics of the prevailing climatic and hydrometeorological processes never change stationary). It is absolutely necessary that future projects are designed, and all projects are operated, taking into account the fact that climate is non-stationary.  Climate change influence is completely dependent and it will not be easily studied seperated by other factors like climate, landuse, landcover, water cycle and anthropogenic factor. The dominant hydrological characteristic of the area is the combination of aridity and uncertainty. Conclusion curriculum in natural environmental science, 2005

Hydrology: requires better understanding of the impact of climate change on reservoirs and aquifers. Assessing water demand requires better understanding of climate change impacts on soil, vegetation, natural and agricultural ecosystems. Hydrological as well as socio-economic studies attempting to predict the gap between supply and demand should not only incorporate social, demographic and political changes, but also the impacts of climate change Recommendations curriculum in natural environmental science, 2005