Abstract
Water management and environmental protection is vulnerable to extreme low flows during streamflow droughts. During the last decades, in most rivers of Central Europe summer runoff and low flows have decreased. Discharge projections agree that future decrease in runoff is likely for catchments in Brandenburg, Germany. Depending on the first-order controls on low flows, different adaption measures are expected to be appropriate. Small catchments were analyzed because they are expected to be more vulnerable to a changing climate than larger rivers. They are mainly headwater catchments with smaller ground water storage. Local characteristics are more important at this scale and can increase vulnerability.
This thesis mutually evaluates potential adaption measures to sustain minimum runoff in small catchments of Brandenburg, Germany, and similarities of these catchments regarding low flows. The following guiding questions are addressed: (i) Which first-order controls on low flows and related time scales exist? (ii) Which are the differences between small catchments regarding low flow vulnerability? (iii) Which adaption measures to sustain minimum runoff in small catchments of Brandenburg are appropriate considering regional low flow patterns?
Potential adaption measures to sustain minimum runoff during periods of low flows can be classified into three categories: (i) increase of groundwater recharge and subsequent baseflow by land use change, land management and artificial ground water recharge, (ii) increase of water storage with regulated outflow by reservoirs, lakes and wetland water management and (iii) regional low flow patterns have to be considered during planning of measures with multiple purposes (urban water management, waste water recycling and inter-basin water transfer). The question remained whether water management of areas with shallow groundwater tables can efficiently sustain minimum runoff. Exemplary, water management scenarios of a ditch irrigated area were evaluated using the model Hydrus-2D. Increasing antecedent water levels and stopping ditch irrigation during periods of low flows increased fluxes from the pasture to the stream, but storage was depleted faster during the summer months due to higher evapotranspiration. Fluxes from this approx. 1 km long pasture with an area of approx. 13 ha ranged from 0.3 to 0.7 ls-1 depending on scenario. This demonstrates that numerous of such small decentralized measures are necessary to sustain minimum runoff in meso-scale catchments.
Differences in the low flow risk of catchments and meteorological low flow predictors were analyzed. A principal component analysis was applied on daily discharge of 37 catchments between 1991 and 2006. Flows decreased more in Southeast Brandenburg according to meteorological forcing. Low flow risk was highest in a region east of Berlin because of intersection of a more continental climate and the specific geohydrology. In these catchments, flows decreased faster during summer and the low flow period was prolonged. A non-linear support vector machine regression was applied to iteratively select meteorological predictors for annual 30-day minimum runoff in 16 catchments between 1965 and 2006. The potential evapotranspiration sum of the previous 48 months was the most important predictor (r2 = 0.28). The potential evapotranspiration of the previous 3 months and the precipitation of the previous 3 months and last year increased model performance (r2 = 0.49, including all four predictors). Model performance was higher for catchments with low yield and more damped runoff. In catchments with high low flow risk, explanatory power of long term potential evapotranspiration was high.
Catchments with a high low flow risk as well as catchments with a considerable decrease in flows in southeast Brandenburg have the highest demand for adaption. Measures increasing groundwater recharge are to be preferred. Catchments with high low flow risk showed relatively deep and decreasing groundwater heads allowing increased groundwater recharge at recharge areas with higher altitude away from the streams. Low flows are expected to stay low or decrease even further because long term potential evapotranspiration was the most important low flow predictor and is projected to increase during climate change. Differences in low flow risk and runoff dynamics between catchments have to be considered for management and planning of measures which do not only have the task to sustain minimum runoff.
Literaturrecherche und Analyse der Bewirtschaftungspläne von 18 deutschen und europäischen Flussgebietseinheiten. Der Bericht untersucht inwieweit die zu erwartenden Auswirkungen des Klimawandels in die ökonomischen Analysen gemäß Wasserrahmenrichtlinie integriert wurden.
Der Bericht beschreibt die Aktivitäten des Projekts RADOST in den fünf Modulen „Netzwerk und Dialog“, „Natur- und ingenieurwissenschaftliche Forschung“, „Sozio-ökonomische Analyse“, „Nationaler und europäischer Politikrahmen/ nationaler und internationaler Austausch“ und „Kommunikation und Verbreitung der Ergebnisse“ und deckt den Zeitraum von April 2012 bis Januar 2013 ab.
Inhalt:
Regionale Aktivitäten:
Klimabündnis Kieler Bucht erhält BMU-Förderung;
Norddeutsche Regionalkonferenz;
Neue Webseite informiert über Küstenschutzbedarf;
RADOST-GIS präsentiert Indikatoren zur Gewässerqualität;
Küstenforschung, Küstennutzung und Küstenschutz;
Überregionale Aktivitäten:
KLIMZUG-Abschlusskonferenz;
Internationale Aktivitäten:
HELCOM-Workshop in Warnemünde;
RADOST auf dem Dupont Summit 2012;
Publikationen:
Ergebnisse der RADOST-Tour 2012;
Integration des Klimawandels in die ökonomischen Analysen nach WRRL
Content:
Regional Activities:
The Bay of Kiel Climate Alliance Receives BMU Support;
Northern German Regional Conference;
New Website Provides Information about the Need for Coastal Protection;
RADOST GIS Presents Water Quality Indicators;
Coastal Research, Use, and Protection;
National Activities:
KLIMZUG Final Conference;
International Activities:
HELCOM Workshop in Warnemünde;
RADOST at the Dupont Summit 2012;
Publications:
Results of the 2012 RADOST Tour;
Integrating Climate Change into Economic Analyses under the EU Water Framework Directive
One of the important parts of the final conference of ‘nordwest2050’ has been the scientific exchange sessions in the House of Science and the Industryclub Bremen. Contributions were based upon a call for papers from October 2013. The scientific committee received almost 100 abstracts where 36 were chosen for oral presentations and 15 for poster presentations (see overview tables below).
Four main topics were discussed in parallel workshops:
• Analysing Impacts and Assessing Vulnerabilities
• Designing and Testing Solutions for Regional Climate Adaptation and Resilience
• Implementing Climate Adaptation and Paths to a Resilient Future
• Resilience for Business: Climate Adaptation Challenge and Strategies of Sectors and Companies
Dieses Rechtsgutachten umfasst 6 Kapitel aus dem Bereich Raum- und Bauplanung mit Bezug zur Anpassung an den Klimawandel und seinen Folgen:
A) Bauleitplanung
B) Bauordnungsrecht
C) Raumordnungsrecht
D) Naturschutzrecht
E) Wasserrecht
F) Anpassung in den Umweltprüfungen
- Bis zum Jahr 2018 kann von einer Stationarität des Füllungsregimes gesprochen werden, erst danach sind größere und mit der Zeit wachsende Absenkungen zu verzeichnen.
- Die klimabedingten Vergrößerungen der Absenkungen sind teilweise erheblich: die maximalen Absenkungen steigen im extremen Fall von 0,5 m im Jahr 2018 bis auf 4,2 m im Jahr 2053 an, diejenigen mit 10% ÜWk. von 0,4 m bis auf 2,4 m. Die wasserfreien Seeflächen betragen maximal über 40% der Fläche bei Vollfüllung.
- Diese Klimafolgen sind am größten in den Seen im Südosten Berlins und nehmen zum Nordwesten ab.
- Die Zunahme der Absenkungen ist am stärksten für Seen, welche im Vergleich zum Zufluss ein großes Volumen besitzen.
Die Obstbauversuchsanstalt Jork hat im Rahmen von KLIMZUG-NORD die Verwundbarkeit von Apfelbäumen gegenüber den Auswirkungen des Klimawandels untersucht. Im Fokus standen dabei neue Schaderreger. Nach der Diagnose erfolgten die Erforschung der Biologie sowie die Erarbeitung einer Bekämpfungsstrategie. Die Ergebnisse fanden unmittelbar Eingang in die Beratungspraxis.
Kurzbeitrag über das im Modellgebiet Elmshorn und Umland angewandte partizipative Verfahren zur Sensibilierung der Akteure vor wasserbezogenen Klimafolgen.