FINAL REPORT PHASE I VULNERABILITY OF WATER RESOURCES IN EASTERN MEDITERRANEAN ECOSYSTEMS

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1 FINAL REPORT PHASE I VULNERABILITY OF WATER RESOURCES IN EASTERN MEDITERRANEAN ECOSYSTEMS 1 INTRODUCTION AND SUMMARY OVERALL PROJECT GOAL AND STRUCTURE FOCUS REGIONS PARTNER INSTITUTIONS KEY RESULTS IN PHASE WP1: Climate and global change scenarios WP2: Water resources, availability/demand/quality WP3: Water and (semi-)natural ecosystems WP4: Water and agriculture WP5: Integration and stakeholder participation Publications OUTLOOK TO PHASE

2 1 INTRODUCTION AND SUMMARY 1.1 OVERALL PROJECT GOAL AND STRUCTURE The mandate of GLOWA is to provide scientific support for sustainable water management under global change. The GLOWA Jordan River Project (GLOWA JR) addresses the vulnerability of water resources in eastern Mediterranean environments under global change and evaluates adaptation options. Natural water availability (per capita) in the Jordan River region is among the lowest in the world and spatially and temporally highly variable (Fig. 1.1). Therefore, the study region is highly vulnerable to changes in availability of water. Fig. 1.1: Spatial variability of precipitation in the study region ( low average annual rainfall correlates with high inter-annual variability in precipitation. Vulnerability to global change will further increase, due to several trends that affect water availability, demand and quality: For example, climate trend analyses have indicated that natural water availability has decreased over the past decades and climate models increasingly agree on further aridification of the eastern Mediterranean under climate change. Also, climate variability and frequency and intensity of hydrometeorological extremes are expected to increase further. At the same time, water demand has increased, following population growth and economic development. Given that population growth rates are among the highest in the world, further increases in demand are expected. Water quality is impacted, too, in particular with respect to salt content, largely due to agricultural activities, irrigation and wastewater management. This pressing water scarcity has immediate impacts on the region s development and the integrity of ecosystems. In particular during drought periods, not all of the competing demands can be fulfilled. Water allocations under increasing scarcity are closely interlinked with the political situation. Given these water-related pressures, regionspecific adaptation options need to be identified and evaluated for their potential to reduce vulnerability of humans and ecosystems and to ensure future water security. Due to the multi-dimensionality of the problem, a large number of transdisciplinary studies are integrated within the GLOWA Jordan River project. Phase 1 of GLOWA JR (which started in Israel and Germany in 2001, in PA and Jordan in 2003) has consolidated available data, provided new baseline data and information and has tested and established empirical and theoretical methods for monitoring, assessing and simulating the regional water resources and their interactions and feedbacks with natural ecosystems and agriculture. Also, phase 1 has initiated the collaboration of the partners and has established the research teams, upon which phase 2 activities rely. GLOWA JR phase 1 had five work packages (Fig 1.2): 3

3 WP1: Climate and global change scenarios WP2: Water resources, availability/demand/quality WP3: Water and (semi-) natural ecosystems WP4: Water and agriculture WP5: Integration and stakeholder participation Fig. 1.2: Project structure (five work packages) of GLOWA Jordan River phase 1. The five work packages are closely interlinked. A central work package concentrates on water resources quantity and quality (WP2) under global change scenarios (climate change and land use change). The input scenarios for WP2 are generated both in WP1 (downscaled climate scenarios for the region) as well as in WP3 and WP4 (land use and land cover scenarios under global change). Further integration between scientific disciplines and between science and water management is achieved through the development of scenarios and an evaluation and decision support tool (WP1 and WP5). Scenarios, in particular climate scenarios, provide the basis for the activities in all other work packages. The two adaptation work packages dealing with natural ecosystems (WP3, focus on green water) and agriculture (WP4, focus on green and blue water), receive scenarios as input from WP1. Modelling activities as well as manipulation experiments simulate the impacts of different climate scenarios in the receiving work packages (2-4). For example, the translation of climate and other scenarios into water availabilities is part of the water resources work package, through the use of hydrological models, eventually also coupled climate and hydrological models. The resulting spatio-temporal patterns of water availability serve as additional input for the other work-packages. At the same time, WP3 and WP4 provide to the hydrological models in WP2 scenarios of land use and land cover in agricultural systems. The translation of climate and other scenarios into water demand of natural and agricultural ecosystems is achieved in the respective work packages with the help of experiments and modeling tools. Feedback to the climate scenarios is generated by developing scenarios of land cover scenarios. All water availability and demand (and water quality) information is integrated in the decision support and evaluation tool, which much like the scenarios is developed jointly between GLOWA scientists and stakeholders. This approach is largely strengthened in phase 2 at the expense of baseline data collection. The results of WP1 to WP5 as well as specific linkages and data flow between work packages are presented in detail in sections 2 to 6 of this report. 4

4 1.2 FOCUS REGIONS For phase 1, we have selected three focus regions for detailed baseline studies (Fig. 1.3). These regions are representative for investigating the main drivers of changes in the water systems in the three countries involved in GLOWA JR. Fig. 1.3: The three focus regions for detailed baseline studies: Upper Jordan River Catchment, Wadi Faria and Wadi Shueib. The three focus regions are: The Upper Jordan River catchment (UJRC) Wadi Faria Wadi Shueib The upper Jordan River catchment represents the less arid part of the catchment, with relatively high precipitation and runoff, and with intensive irrigated agriculture. This focus region in Israel is well suited to assess the effects of land management in combination with climate change on water quality. Further, climate effects on runoff in the headwaters of the Jordan River, including changes in snowfall are simulated. Wadi Faria in the West Bank drains into the lower Jordan River and belongs to the more arid part of the basin, with low precipitation though steep climatic gradients, and intermittent runoff only during rainfall events. Agriculture in the West Bank is mostly rain-fed and water supply relies primarily on ground water. A focus of GLOWA JR for this region is on the conjunctive use of ground and surface water and on the management of wastewater. Similar to Wadi Fariah, Wadi Shueib in Jordan also drains into the lower Jordan River. It also belongs to the more arid part of the basin, but is characterized by a steep climatic gradient ranging from dry Mediterranean climate to arid conditions. Wadi Shueib, with its reservoir and a wastewater treatment plant in the catchment, represents one of the highly modified wadis in the basin with little natural runoff left. GLOWA JR assesses, for example, different irrigation practices and related water productivities. For more detailed descriptions of the three focus regions, see WP5. 5

5 1.3 PARTNER INSTITUTIONS The following institutions participated in phase 1 of GLOWA JR: Bochum University wastewater (WP4) GSF, National Research Center for Environment & Health isotopes (WP2) Hannover University water productivity (WP4) IME, Schmallenberg water quality (WP2) IMK-IFU climate scenarios (WP1) Kassel University SVAT modelling (WP2) PIK Potsdam Institute for Climate Impact Research climate scenarios (WP1) Potsdam University vegetation modelling, vegetation and global change (WP3), coordination Tübingen University vegetation and global change (field experiments) (WP3), coordination Al Quds University crop experiments (WP4) An Najah University hydrological monitoring & modelling (WP2) PALAST Palestinian Academy of Science, climate scenarios (WP1) PHG Palestinian Hydrology Group, data synthesis, integration, stakeholders (WP5) EcoConsult - data synthesis, scenarios, integration, stakeholders (WP5) Mutah University crop experiments (WP4) University of Jordan - hydrological monitoring (WP2) Bar-Ilan University soil experiments (WP3) Ben Gurion University agricultural experiments & modelling (WP4) Haifa University economic modelling (WP4), vegetation modelling (WP3) Hebrew University vegetation experiments (WP3), wastewater experiments (WP4) Kineret Limnological Laboratory hydrological data & modelling (WP2) STAV-GIS hydrological data & modelling (WP2) Tel Aviv University climate scenarios (WP1), vegetation experiments (WP3) Tel Hai College groundwater modelling, water quality (WP2) Volcani Center wastewater experiments (WP4) Weizman Institute vegetation experiments and modelling (WP3) 1.4 KEY RESULTS IN PHASE 1 Phase 1 of GLOWA JR has established key relationships of water, climate, natural ecosystems and agriculture for selected sites in the Jordan River region. 6

6 1.4.1 WP1: Climate and global change scenarios A climate database for GLOWA JR was consolidated, climate trends were analyzed and initial climate scenarios were produced by means of statistical analyses and statistical and dynamic downscaling of global climate models. Over the past decades an increase Red-Sea-Trough frequency connected to an increasing number of dry spells has been observed as well as an increase in hot spells. While there is still considerable uncertainty about climate trends, in particular for precipitation intensity and distribution, in the long run (several decades) further aridification of the region (higher temperatures and possibly lower precipitation, increasing climate variability) are expected for the eastern Mediterranean (e.g. Milly et al. 2005, Lionello et al 2006). These findings have highlighted the need for further downscaling of global climate simulations. In phase 2 of GLOWA JR, regional climate simulations at increasingly higher resolution (eventually 6 km), will be employed to represent key regional features (in particular topography) and provide input for subsequent hydrological, ecological, agricultural and socioeconomic vulnerability assessments WP2: Water resources, availability/demand/quality Surface water balances have been established for the focus regions Wadi Faria, Wadi Shueib and the Upper Jordan River Catchment (UJRC). Horizontal and vertical water fluxes, rainfall-runoff relationships and baseflow separation (and trend analysis), all derived from field measurements in combination with hydrological models (SVAT models, rainfall-runoff models and water balance models that were calibrated for the focus regions for current climate and land use), are now available as a basis for hydrological simulations for different (climate, land use and other) scenarios. Further, differences between above and below ground watershed size of Jordan tributaries were determined. Additional hydrological equipment (parshall flumes with data loggers and rainfall gauges) were installed in Wadi Faria contributing to a nested runoff and precipitation measurement and monitoring network. Phase 2 builds upon this consolidation of data and development and adaptation of models, in order to regionalize the simulation of horizontal and vertical water fluxes and eventually provide water availabilities for different scenarios, as input to the WEAP and SAS integration tools WP3: Water and (semi-)natural ecosystems Since natural ecosystems in the region are mainly driven by water and climatic gradients are very steep, even small climatic changes will have drastic effects on plant and animal species. A set of interrelated integrative studies investigates climate change effects and land use change effects on structure, function, and economic value of natural ecosystems in the entire Jordan River Basin, contributing to the GLOWA goal of evaluating water productivity under global change. 7

7 Our overall results indicate that transitional ecosystems (semi-desert) may be the most vulnerable to the projected changes in rainfall patterns. Small-scale effects of vegetation on soil moisture shift from positive to negative along the gradient with the semi-arid system being located at the switching point. In parallel, the semi-arid is the turning point at which positive interactions among plants change to negative ones. This is important since the type of interactions determines the plant spatial pattern with a more clumped pattern under positive interactions and regular spacing with competition. This in turn has drastic effects on hydrology and on soil erosion, i.e. the projected scenarios may lead to increased runoff and less retention of water by plants, which in turn could lead to a positive feedback loop of desertification. Mes. Med. Mediterranean semi-arid arid Fig. 1.4: Climate change scenario: Nonlinear increase in erosion risk Another consequence of the shifts in interaction strength is that plants which are adapted to competitive environments may go extinct when facing less competitive but more stressful abiotic conditions. Intriguingly, this may apply also to species with a very wide distribution range, since populations may be highly adapted to local climatic conditions. Our socio-economic studies indicate that the transition from the semi-arid to arid landscapes implies the largest loss in economic services, when compared to all other pairwise transitions. Therefore, we conclude that management efforts to adapt to or mitigate climate change effects on open space should focus on the semi-arid regions. In studies on afforestations in formerly grazed land in the semi-arid regions, we could show that water use efficiency of this substitute vegetation can be very high. Therefore, if water use efficiency were a high priority for stakeholders, afforestation may be a management alternative for reducing unproductive water loss. These positive effects must be, however, balanced against potential negative effects on plant species diversity. Studies focusing on single species of plants and animals indicated a high extinction risk for species inhabiting semi-arid and Mediterranean areas. These scenarios will enter the SAS scenario discussion in phase 2 as qualitative or quantitative data (e.g. extinction probabilities of species, biodiversity change). In an inter-work package study focusing on the sustainability of alternative cropping systems, we could show that modern, intensively treated fields of the West Bank harbor a lower overall number of wild vascular plant species and a lower number of species per unit area than traditionally used fields. Additionally, the fields under traditional use are very important for the conservation of a number of rare and economically important crops. Therefore, we conclude that the ongoing intensification of the agricultural landuse in the West Bank would lead to a greatly reduced regional biodiversity and the loss of a very special kind of cultural heritage of Palestine, i.e. the species that evolved under human influence. Phase 2 will be devoted to validating the findings from the climate gradient studies by expanding the spatial scale of our studies to (a) wetter forested areas and (b) to highly overgrazed areas in Jordan, and by expanding the spatial scale of our vegetation models to a catchment scale. Our ultimate goal will be basin-wide vulnerability maps for natural 8

8 ecosystems under different scenarios of climate and land use change. Water productivity maps will be produced, as an input to WEAP, to enable trading off management options as different as agricultural use and ecosystem protection against each other. From an ecosystem point of view, water productivity will be quantified in terms of ecosystem services (e.g. productivity, non-market value, biodiversity) and function (e.g. productivity, resistence and resilience in response to changes) WP4: Water and agriculture Water fluxes in agriculture were quantified, using field measurements, remote sensing and SVAT modelling. Impacts of reduced water availability on agriculture from rainfall reduction and/or temperature increase were quantified with respect to productivity and farmer s profits, using a bioproductivity module coupled to a SVAT model and additionally by using an economic model. Initial results indicate an increased yield at the cost of higher water demand and subsequently lower profitability for irrigated agriculture. Intercropping was shown to reduce runoff and soil erosion and enhance farmer s income during dry years. Similarly the return to traditional, local varieties of vegetable can increase productivity under rainfed conditions, due to higher water use efficiency. Water quality effects of agriculture were determined, in particular with respect to wastewater reuse. It was shown that the effects of wastewater on soil properties, including loss of organic matter due to enhanced microbial activity are very site specific and therefore can not be generalized. At the soil surface, wastewater irrigation can cause hydrophobicity and may reduce aggregate stability, making the soils more susceptible to run-off generation and erosion. The risk of groundwater contamination from wastewater-borne pollutants such as heavy metals or nutrients such as N or P seems to be rather low. Further, in the UJRC an increase in nutrient concentrations mostly as a result from agricultural practices was observed. Macropores and groundwater flow were identified as potential pathways for nutrient transport to the Jordan river, depending on land management and groundwater levels, e.g. due to mobilization from changes in redoxpotential. Natural and synthetic hormones were tested as tracers for the fate of organic pollution from agricultural activities and municipal wastewater. It was found that they are useful to trace pollution in surface waters, but not in soils and groundwater, due to retention effects. Phase 2 will continue to focus on (1) agricultural water productivity under different scenarios, using a combination of hydrological and agro(eco)nomic models and (2) improved wastewater reuse, providing e.g. land suitability maps for reuse of wastewater of different qualities. Agricultural water demand and productivity as well as wastewater reuse information will feed into the WEAP and SAS integration tools. 9

9 1.4.5 WP5: Integration and stakeholder participation Due to the fact that the proposed coherent and region-wide integrated modelling in GLOWA JR phase 1 was not funded, separate integration efforts took place in each of the focus regions, i.e. in Wadi Faria, Wadi Shueib and UJRC. For these focus regions, GIS-based databases were compiled, e.g. on meteorology, hydrology and land use, and the focus regions were characterized with respect to water availability, demand and quality. These compilations will serve as input for more systematic integration in phase 2 by means of the WEAP data and decision support tool and the SAS scenario development and analysis. Despite the lack of systematic integration activities, a wide range of cross-work package and international collaborations were achieved. Data sets and initial regional climate modelling results were made available project-wide. Within each of the focus areas, inter-disciplinary assessements of water availability, demand and quality were achieved in phase 1, that provide a basis for upscaling of the water systems to the full region in phase 2, using the WEAP tool. Also, in each of the focus regions, stakeholder involvement was promoted through a series of workshops which were intended to better understand stakeholder s perspectives and to match the GLOWA JR research capacity and emphasis with local or national information requirements. Also initial scenarios were developed together with the stakeholders. This was also done in preparation of more systematic and region-wide stakeholder involvement in phase 2 of the project by means of the SAS scenario approach Publications 198 publications have been produced in phase 1, which include 127 peer-reviewed papers, 8 book chapters and 64 conference abstracts (see appendix 8.3). 1.5 OUTLOOK TO PHASE 2 Based upon the results of phase 1, all contributions of phase 2 will be integrated in a common framework that is designed for the GLOWA mandate to provide scientific support for water management. This integration is based upon the key tools, WEAP, the Water Evaluation and Planning tool and SAS, the Story and Simulation scenario development. 10

10 Fig.: 1.5: Initial concept of integration with WEAP, SAS (and newly added:) LandShift in phase 2. WEAP will integrate and visualize all water supply, demand and quality information generated in GLOWA JR, and allows to simulate and assess the system-wide effects of global change effects and management interventions. SAS, the Story and Simulation approach will integrate GLOWA JR data with stakeholders knowledge, by generating fully quantitative and at the same time realistic and agreed upon scenarios of the future water system. Both tools are adapted for the region and will be developed and applied in constant cooperation with key stakeholders. They are designed to support decision making by providing integrated views of the regional water system at reduced complexity, also addressing inherent uncertainties. The integration in phase 2 is based on the green and blue water concept (Falkenmark and Rockström 2004), aiming at a better understanding of the eco-hydrological links and feedbacks between water, vegetation and land use, for evaluating different water management and allocation options, in order to maximize the benefits for humans and ecosystems under different scenarios. In phase 2, basic data collection will be reduced to a minimum, except for cases where new field work was established in phase 1 and long-term effects need to be established (WP3). Instead, we will largely build on data obtained in phase 1, and ain efforts are concentrated on integrating available data and information from GLOWA and beyond, and simulating different scenarios. Results will be generalized and regionalized beyond the focus regions of phase 1 to the full Jordan River basin. 11