551 Geologie, Hydrologie, Meteorologie
Exploring Transboundary Water Dependencies: Identifying the Berlin–Brandenburg Precipitationshed
(2025)
Developing a deeper understanding of the interconnected atmospheric systems distributing the Earth's water resources is critical for managing scarce water supplies and maintaining water security in a changing climate. This study identifies and analyzes Berlin–Brandenburg’s precipitationshed, the primary evaporative moisture sources contributing to regional rainfall, using the WAM2layers moisture tracking model with ERA5 reanalysis data for the period 2000–2024.
By analyzing both seasonal patterns and interannual variability, including anomalous years marked by droughts and excessive rainfall, the study explores shifts in the balance between oceanic and terrestrial sources of moisture. Findings reveal a seasonally dynamic but stable precipitationshed: the North Atlantic Ocean dominates in winter, while terrestrial contributions from Germany, France, Poland, and the United Kingdom intensify during warmer months. Hydroclimatic extremes disrupt seasonal norms by reshaping the spatial distribution and relative intensity of key moisture sources, at times amplifying marine influence or reinforcing terrestrial recycling, depending on the nature and timing of the event. This is the first study to explicitly map Berlin–Brandenburg’s precipitationshed and assess the spatio-temporal consistency of its sources.
The results highlight the need to embed atmospheric moisture transport considerations into transboundary water governance frameworks, recognizing that land-use decisions and ecosystem management in both local and distant source regions directly influence regional water availability. As climate variability intensifies, coordinated action across these spatially connected landscapes will be essential to safeguard long-term water security.
Da ca. 4 % der deutschen Treibhausgasemissionen und mehr als ein Drittel der aus der Landwirtschaft stammenden Treibhausgasemissionen durch die entwässerungsbasierte Nutzung von Moorböden verursacht sind, besteht aus Klimaschutzsicht dringender Handlungsbedarf einen alternativen Umgang mit diesen Flächen umzusetzen. Dies gebieten auch die Anforderungen an nachhaltige Nutzungsformen mit Blick auf den Boden-, Biodiversitäts- und Wasserschutz. Zur Erreichung dieser Ziele ist es zwingend notwendig die Wasserstände auf Moorböden großflächig bis 2030 auf mindestens 30 cm unter Flur und bis 2050 generell oberflächennah anzuheben.
Im Land Brandenburg werden 165.000 Hektar Grünland auf Moorböden oder Moorfolgeböden in einem mehr oder weniger entwässerten Status genutzt. Um Schritt für Schritt dem oben genannten Ziel näher zu kommen und auf nassere Bewirtschaftung umzustellen, wurde als Anreiz 2016 die Agrarumwelt- und Klimaschutzmaßnahme (AUKM) Moorschonende Stauhaltung angeboten. Mithilfe dieser Maßnahme sollen Treibhausgasemissionen eingespart und der Landschaftswasserhaushalt durch den Wasserrückhalt in der Agrarlandschaft stabilisiert werden. Dies ist insbesondere im Land Brandenburg von besonderer Bedeutung, denn durch den Klimawandel werden zukünftig auch die regionalen Wasserressourcen stark beeinflusst. Die Broschüre stellt die AUKM Moorschonende Stauhaltung vor, erläutert Förderrahmen und Antragsstellung, gibt Handlungsempfehlungen und geht auf mögliche Netzwerke und Finanzierungsmöglichkeiten ein.
To develop measures to reduce the vulnerability of forests to drought, it is necessary to estimate specific water balances in sites and to estimate their development with climate change scenarios. We quantified the water balance of seven forest monitoring sites in northeast Germany for the historical time period 1961–2019, and for climate change projections for the time period 2010–2100. We used the LWF-BROOK90 hydrological model forced with historical data, and bias-adjusted data from two models of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) downscaled with regional climate models under the representative concentration pathways (RCPs) 2.6 and 8.5. Site-specific monitoring data were used to give a realistic model input and to calibrate and validate the model. The results revealed significant trends (evapotranspiration, dry days (actual/potential transpiration < 0.7)) toward drier conditions within the historical time period and demonstrate the extreme conditions of 2018 and 2019. Under RCP8.5, both models simulate an increase in evapotranspiration and dry days. The response of precipitation to climate change is ambiguous, with increasing precipitation with one model. Under RCP2.6, both models do not reveal an increase in drought in 2071–2100 compared to 1990–2019. The current temperature increase fits RCP8.5 simulations, suggesting that this scenario is more realistic than RCP2.6
1. Forest management influences a variety of ecosystem structures and processes relevant to meso- and microclimatic regulation, but little research has been done on how forest management can mitigate the negative effects of climate change on forest ecosystems.
2. We studied the temperature regulation capacity during the two Central European extreme summers in 2018 and 2019 in Scots pine plantations and European beech forests with different management-related structural characteristics.
3. We found that the maximum temperature was higher when more trees were cut and canopy was more open. Logging 100 trees per hectare increased maximum temperature by 0.21–0.34 K at ground level and by 0.09–0.17 K in 1.3 m above ground. Opening the forest canopy by 10% significantly increased Tmax, measured 1.3 m above ground by 0.46 K (including pine and beech stands) and 0.35 K (only pine stands). At ground level, Tmax increased by 0.53 K for the model including pine and beech stands and by 0.41 K in pure pine stands. Relative temperature cooling capacity decreased with increasing wood harvest activities, with below average values in 2018 (and 2019) when more than 656 (and 867) trees per hectare were felled. In the pine forests studied, the relative temperature buffering capacity 1.3 m above ground was lower than average values for all sample plots when canopy cover was below 82%. In both study years, mean maximum temperature measured at ground level and in 1.3 m was highest in a pine-dominated sample plots with relatively low stand volume (177 m3 ha−1) and 9 K lower in a sample plot with relatively high stock volumes of Fagus sylvatica (>565 m3 ha−1). During the hottest day in 2019, the difference in temperature peaks was more than 13 K for pine-dominated sample plots with relatively dense (72%) and low (46%) canopy cover.
4. Structural forest characteristics influenced by forest management significantly affect microclimatic conditions and therefore ecosystem vulnerability to climate change. We advocate keeping the canopy as dense as possible (at least 80%) by maintaining sufficient overgrowth and by supporting deciduous trees that provide effective shade.