Vulnerability of Water Resources in East-Mediterranean Environments
The research program ‘Global Change in the Hydrological Cycle’ (GLOWA) consists of long-term research projects with a perspective of 9 years. The overall aim of GLOWA is to develop simulation tools to develop strategies for sustainable and future-oriented water management at regional level, while taking into account global environmental changes as well as changing socio-economic conditions. GLOWA projects are currently carried out in five case study regions (Danube, Elbe, Volta, Jordan River, and Impetus with a regional emphasis on Morocco and Benin) under the prevailing specific natural, political and societal conditions.
Since 2005 the Centre for Environmental Systems Research (CESR) is involved in the GLOWA-Jordan River Project with projects dealing with scenario development, eco-hydrological modeling and land-use change modeling. In phase III of GLOWA JR which has started in 2009 the overall focus of the project is on integration and dissemination of project results. Here, the CESR plays a central role being responsible for integrative scenario development and land-use change modeling:
(1) The aim of the GLOWA JR scenario exercise is to develop and analyze scenarios of different water and land management strategies to cope with global and regional change. Scenario storylines are developed under decisive participation of stakeholders and other experts from Israel, Jordan and Palestine. Quantitative elements of storylines are provided by different sub-projects aiming at a useful integration of state of the art scientific results of the project.
(2) The land-use change model LandSHIFT.R is adapted to regional conditions and applied to compute scenarios of changes in land-use and cover that are based on the scenario assumptions derived from (1). These land-use change scenarios will serve as a basis for land-use based questions of water management, such as e.g. water demand and availability for agricultural purposes.
During phase two of the project, the four “GLOWA Jordan River Scenarios of Regional Development under Global Change” have been developed with stakeholders from the region by applying the so-called “Story and Simulation” or SAS approach. A characteristic of this approach is that it integrates qualitative knowledge and quantitative elements in a balanced way and consequently allows for the integration of mainly quantitative results from the different scientific sub-groups of the project. The quantified scenarios cover the area of all three participating countries and the time up to 2050. They serve as drivers for the different models applied in GLOWA JR. Simulation results were fed back to the process of scenario development so that the scenarios could be further developed and checked for their plausibility in an iterative way.
The land-use change model LandSHIFT.R was applied in a subsequent step to compute four scenarios of land-use- and –cover change in Israel, Jordan and Palestine. For this purpose the scenario driving forces that were developed during the scenario process were taken up as well as simulation results of other models of GLOWA JR as for example agro-economic models. These simulations result in four scenarios of land-use change with a spatial resolution of 1x1 km. They provide the basis for the evaluation of the impacts of different ways of land use on water resources in the Jordan River basin.
First simulation runs with the hydrological model TRAIN show spatially heterogeneous impacts of changing land cover on water availability. An expansion of grazing areas and sealed areas lead to increasing water availability whereas increasing areas for agricultural use result in decreasing water availability. Additionally, TRAIN simulations show a clear impact of changing climate conditions: Even a very probable increase of temperature results in a higher deficit between water availability and water demand. Simulation results also show that decreasing precipitation intensifies the decrease in water availability and that the drought susceptibility could increase considerably.
The project will be continued in GLOWA JR phase three by developing and analyzing scenarios for integrated water and land resource management which will build on the regional development scenarios developed in phase two. This scenario exercise will be guided by three questions:
(1) The “New Water” Question: How can various “new” water sources contribute to future water resource needs of the region?
(2)The “Land Use” Question: To what extent can land use planning contribute to sustainable water management under different scenarios?
(3)The “Climate Extreme” Question: What will be the effect of climatic extremes on the regional water balance and sustainable management of water resources in the region?
September 2005 − December 2011