SP 5: Water Resources Scenarios for Case Study Regions

‘Water Resources Scenarios for CS regions’ provides national planners and water basin managers a unique insight in the process of scenario development on water shortage and gives estimations of future water stress based on socio-economic and climate changes at global, continental and river basin scale.

The most recent scenarios of IPCC concluded that “continued greenhouse gas emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th century”. This will lead to more widespread water stress in areas affected by drought increases.

This synthesis study makes an assessment of WaterGAP simulations, which have been executed in an earlier stage in the NeWater project. For this assessment improved and downscaled climate scenarios will be compared with the original climate scenarios in a qualitative way by evaluating and comparing their PDSI-index for certain river basins. The PDSI-index (Palmer Drought Severity Index) is a meteorological drought index which is calculated using temperature, precipitation and the local available water content of the soil see figure:

PDSI index for climate scenarios

The results over certain periods (e.g 2050) concerning water shortage and water stress for different river basins can be simulated based on recent climate scenarios, providing drought information on a 25 X 25 km2 on a monthly basis, which make seasonal fluctuation visible and predictions of the extreme droughts events for the NeWater river basins.

River basin managers and national planners from water related sectors can use the results in their future planning. EU policy may use the outcome for 2050 for visions on their long term development and the consequent review of water related legislation (directives). The study will be presented as a journal paper to be published in 2009 guided by a policy teasing branch activity.