TY  - JOUR
A1  - Pfister, L.
A1  - Kwadijk, J.
A1  - Musy, A.
A1  - Bronstert, Axel
A1  - Hoffmann, L.
T1  - Climate change, land use change and run-off prediction in the Rhine-Meuse basins
N2  - As a consequence of increasing winter rainfall totals and intensities over the second half of the 20th century, signs of increased flooding probability in many areas of the Rhine and Meuse basins have been documented. These changes affecting rainfall characteristics are most evidently due to an increase in westerly atmospheric circulation types. Land use changes, particularly urbanization, can have significant local effects in small basins (headwaters) with respect to flooding, especially during heavy local rainstorms, but no evidence exists that land use change has had significant effects on peak flows in the rivers Rhine and Meuse. For the 21st century, most global circulation models suggest higher winter rainfall totals. Most hydrological simulations of the Rhine-Meuse river basins suggest an increased flooding probability, with a progressive shift of the Rhine from a 'rain-fed/meltwater' river into a mainly 'rain-fed' river. A very limited effect of changes in land use on the discharge regime seems to exist for the main branches of the Meuse and Rhine rivers. For mesoscale basins, future changes in peak flows depend on the changes in the variability of extreme precipitations in combination with land use changes. Copyright (C) 2004 John Wiley Sons, Ltd
Y1  - 2003
SN  - 1535-1459
ER  - 
TY  - JOUR
A1  - Zehe, E.
A1  - Ehret, U.
A1  - Pfister, L.
A1  - Blume, Theresa
A1  - Schroeder, Boris
A1  - Westhoff, M.
A1  - Jackisch, C.
A1  - Schymanski, Stanislauv J.
A1  - Weiler, M.
A1  - Schulz, K.
A1  - Allroggen, Niklas
A1  - Tronicke, Jens
A1  - van Schaik, Loes
A1  - Dietrich, Peter
A1  - Scherer, U.
A1  - Eccard, Jana
A1  - Wulfmeyer, Volker
A1  - Kleidon, Axel
T1  - HESS Opinions: From response units to functional units: a thermodynamic reinterpretation of the HRU concept to link spatial organization and functioning of intermediate scale catchments
JF  - Hydrology and earth system sciences : HESS
N2  - According to Dooge (1986) intermediate-scale catchments are systems of organized complexity, being too organized and yet too small to be characterized on a statistical/conceptual basis, but too large and too heterogeneous to be characterized in a deterministic manner. A key requirement for building structurally adequate models precisely for this intermediate scale is a better understanding of how different forms of spatial organization affect storage and release of water and energy. Here, we propose that a combination of the concept of hydrological response units (HRUs) and thermodynamics offers several helpful and partly novel perspectives for gaining this improved understanding. Our key idea is to define functional similarity based on similarity of the terrestrial controls of gradients and resistance terms controlling the land surface energy balance, rainfall runoff transformation, and groundwater storage and release. This might imply that functional similarity with respect to these specific forms of water release emerges at different scales, namely the small field scale, the hillslope, and the catchment scale. We thus propose three different types of "functional units" - specialized HRUs, so to speak - which behave similarly with respect to one specific form of water release and with a characteristic extent equal to one of those three scale levels. We furthermore discuss an experimental strategy based on exemplary learning and replicate experiments to identify and delineate these functional units, and as a promising strategy for characterizing the interplay and organization of water and energy fluxes across scales. We believe the thermodynamic perspective to be well suited to unmask equifinality as inherent in the equations governing water, momentum, and energy fluxes: this is because several combinations of gradients and resistance terms yield the same mass or energy flux and the terrestrial controls of gradients and resistance terms are largely independent. We propose that structurally adequate models at this scale should consequently disentangle driving gradients and resistance terms, because this optionally allow sequifinality to be partly reduced by including available observations, e. g., on driving gradients. Most importantly, the thermodynamic perspective yields an energy-centered perspective on rainfall-runoff transformation and evapotranspiration, including fundamental limits for energy fluxes associated with these processes. This might additionally reduce equifinality and opens up opportunities for testing thermodynamic optimality principles within independent predictions of rainfall-runoff or land surface energy exchange. This is pivotal to finding out whether or not spatial organization in catchments is in accordance with a fundamental organizing principle.
Y1  - 2014
U6  - https://doi.org/10.5194/hess-18-4635-2014
SN  - 1027-5606
SN  - 1607-7938
VL  - 18
IS  - 11
SP  - 4635
EP  - 4655
PB  - Copernicus
CY  - Göttingen
ER  -