GLOWA-Elbe - Impacts of Global Change on the Water Cycle in the Elbe Region | Umweltbundesamt

Scenarios concerning the future trends of essential parameter affecting the water quantity and water quality in the Elbe drainage area have been developed. Beside the climate change related scenarios, scenarios for population development and settlement structure, the development of the energy sector, agricultural policy and land use have been developed as well. IPCC emission scenarios A1 and B2 had been used. Scenario calculations are based on the ECHAM4/OPYC3 model. By means of the statistical downscaling method (STAR), climate parameters are simulated per day up to 2055 using local monitoring data from 1951 to 2000. In addition, the climate changes in the Elbe region have been simulated for 2020-2049 using the regional climate model REMO, which is driven by the global ECHAM4/OPYC3 model as well.

wind speed, humidity, sunshine

2049, 2052, 2055

Direct and indirect impacts of global change have been considered, such as those on the surface water quality, the quality of the environment and the socio-economic capacity of the Elbe region. This includes nutrient and pollutant emissions into surface waters, water supply, water demand and surface water availability. Another consequence is the decrease in annual precipitation, reduced evaporation, reduced surface and subsurface water runoff and reduced groundwater recharge, which affects agricultural yields (e.g. winter crop). Stronger and more frequent heavy rainfall events lead to consequences for flood protection.

Vulnerability analysis for different areas of conflict are performed to evaluate and assess the socio-economic impact (e.g. for surface water use by thermal power plants, industry, water transfers, watergates, nitrogen retention, wetlands, grassland management, water plants, aquaculture, and tourism on mining lakes). Therefore, the vulnerability of each user group regarding to low or declining surface water availabilities will be analyzed by means of quantitative and qualitative surveys and literature studies. In addition, integrated strategies for the sustainable management of water use conflicts will be considered, which may include adaptive capacity to global change in the broader sense as well.

As part of a global change adaptation measures for the water management need to be developed.

The Integrative Methodological Approach (IMA), which was developed in the first phase of the GLOWA-Elbe project, plays a central role in structuring the research content, in the temporal organization and in assuring the convergence and consistency of the different working areas. It is a methodological formalism of systems analysis, which allows target-oriented scenario analyses through involvement of users and other persons affected. IMA includes definitions and categories for the formulation of problems and lays down an order for the steps to be taken in the scenario analysis. At the same time IMA represents an application- and practice oriented research philosophy to evaluate action strategies under the uncertainties of global change. There are four research steps:

(1) "Scenarios": Developing scenarios of possible future trends based on changes in general and regional almost uncontrollable conditions on the one hand (climate, global market) and measures by the actors (according to the courses of action) on the other hand.

(2) "Definition of indicators and criteria": Establishing specific sustainability indicators and criteria for assessing the impact.

(3) "Impact analysis": Analyzing of consequences using available data, models, expert knowledge, literature, etc.

(4) "Evaluation": Evaluation using multi-criteria analysis and derivation and evaluation of long-term recommendations and strategies concerning the conflicting areas of surface water availability, surface water quality and flood risk, which can serve as guidelines for politics and economy of the region.

Related to these four steps the IMA shall enable the participation of all persons involved in the research and decision-making process (such as stakeholders, decision makers in politics and economy, conservationist and citizens).

Conflict analyzes will be carried out for the conflict areas of surface water availability (the energy sector in particular), surface water quality and flood risk. There are conflicts, especially concerning the water use and thus integrated strategies for a sustainable and proactive management of water and water bodies are needed. In the Spree region conflicting uses of water between water-related sectors and federal states such as following, will be investigated as well: inland fisheries, agriculture, tourism in the Spree Forest and the Lusatian lakes, nature conservation, water conservation and lignite mining and between the interests of the states of Saxony, Brandenburg and Berlin (conflicts can be exacerbated due to the enormous water demand for flooding of the open-cast mines).