Hydro-ecological modeling and landscape analysis for high-altitude wetland classification and assessment of climate change impacts on high-altitude wetlands across environmental and elevational gradients
Zusammenfassung der Projektergebnisse
The research project was focusing on the assessment of hydro-ecological functions of high-altitude wetlands and its implication for wetland classification, the scale-related relevance of wetland process dynamics in high-altitude catchment hydrology as well as impacts of climate change on the hydrological dynamic of high-elevation wetlands across environmental and elevational gradients. Thus, nine nested sub-catchments located in the upper Merced and Tuolumne Rivers and with catchment areas ranging from 8 to 831 km^2 at elevations between 1166 m and 3985 m asl. were simulated. To assess spatially distributed hydrological runoff and storage dynamics, the hydrological modelling was performed by applying the Hydrological Response Units approach and the processoriented JAMS/J2000 model which was adapted to high-altitude conditions. The model parameters were available from previous studies, literature and field work. The model results achieved with high accuracies indicate that the basins differing in catchment characteristics show significant scale-related differences in their spatial and temporal pattern of ground water recharge, storage dynamics, evapotranspiration and subsurface/surface runoff generation. When compared to snowmelt the overall contribution of wetlands to runoff totals is relatively small. However, the modelling reveals that meadows affect the timing and the amount of runoff at all scales, but those effects vary with tributary catchment characteristics as well as wetland percentage (0.3 - 6.8%) within the basin. The combined analysis of field data, existing data provided by the host institution and collaborating partners as well as model results was used to identify different wetland types occurring in the Sierra Nevada and to develop a better understanding of their hydrological functions. In addition, the modelling of climate change scenarios showed that some hydrological dynamics (runoff response and dryout) will be affected by climate change, but those will vary depending on wetland size, size of contributing area, elevation, soil and vegetation characteristics and the state of degradation. The research project was conducted within a DFG scholarship for Jörg Helmschrot who was working with the Mountain Hydrology Research Group led by Prof. Dr. Jessica Lundquist at the Department of Civil and Environmental Engineering at University of Washington. Further research activities focusing on forecast models for Sierra Nevada basins were initiated in collaboration with UW Seattle, US Geological Survey and San Francisco Powers and Waters.
Projektbezogene Publikationen (Auswahl)
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(2010). Analyzing the Locations, Severity and Frequency of Cold Air Pools (CAP) in the Sierra Nevada, California. AGU Fall Meeting, San Francisco, USA, 13-17 December
Kunz, A., Helmschrot, J., Lundquist, J.D.
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(2010). Impact of High-altitude Meadows on Runoff Dynamics Across Environmental and Elevational Gradients in the Sierra Nevada, California. AGU Fall Meeting, San Francisco, USA, 13-17 December
Helmschrot, J., Lundquist, J.D., Krause, P.
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(2010). Impact of high-altitude meadows on runoff dynamics across environmental and elevational gradients in the Sierra Nevada, California. Yosemite Hydroclimate Meeting, Yosemite Valley, 7/8 October 2010
Helmschrot, J., Lundquist, J.D.
