Gertraud Meißl

Investigating the impact of initial soil moisture conditions on total infiltration by using an adapted double-ring infiltrometer

ABSTRACT This study presents an adaptation of the double-ring infiltrometer (DRI) device, which allows several infiltration experiments to be conducted at the same location. Hence, it becomes possible to use the DRI method to investigate infiltration behaviour under different initial soil moisture conditions. The main feature is the splitting of the inner ring into two parts. While the lower part remains in the soil throughout the investigation period, the upper part is attached to the lower one just before the infiltration experiment. This method was applied to eight test sites in an Alpine catchment, covering different land-use/cover types. The results demonstrated the applicability of the adapted system and showed correlations between total water infiltration and initial soil moisture conditions on pastures, independent of the underlying soil type. In contrast, no correlation was found at forest sites or wetlands. Thus, the study emphasizes the importance of paying special attention to the impact of initial soil moisture conditions on the infiltration—and consequently the runoff behaviour—at managed areas. Given the differences in the total infiltrated water of between 30 and 1306 mm, consideration of the interplay between initial soil moisture conditions, land-use/cover type, and soil properties in rainfall–runoff models is a prerequisite to predict runoff production accurately. EDITOR Z.W. Kundzewicz; ASSOCIATE EDITOR not assigned

Climate change effects on hydrological system conditions influencing generation of storm runoff in small Alpine catchments

1 Institute of Geography, University of Innsbruck, Innsbruck, Austria 2 Institute of Meteorology, University of Natural Resources and Life Sciences, Vienna, Austria Department of Natural Hazards, Federal Research and Training Centre for Forests, Innsbruck, Austria 4 Institute for Earth and Environmental Sciences, University of Potsdam, Potsdam, Germany Correspondence Gertraud Meißl, Institute of Geography, University of Innsbruck, Innsbruck, Austria. Email: gertraud.meissl@uibk.ac.at

Modelling peak runoff in small Alpine catchments based on area properties and system status

Floods are an often occurring natural hazard in the Alps and other mountainous regions. Thereby, also small mountain torrents can pose a major threat. Torrent catchments normally incorporate several altitudinal belts and often exhibit a steep relief and react rapidly to precipitation, particularly to small scale events of high intensity in the form of convection cells. If a catchment is affected by such an event then increased surface runoff and rapid subsurface flow take place and consequentially induce a rapid and strong rise in discharge.

Modelling forest snow processes with a new version of WaSiM

ABSTRACT We present a new model extension for the Water balance Simulation Model, WaSiM, which features (i) snow interception and (ii) modified meteorological conditions under coniferous forest canopies, complementing recently developed model extensions for particular mountain hydrological processes. Two study areas in Austria and Germany are considered in this study. To supplement and constrain the modelling experiments with on-site observations, a network of terrestrial time-lapse cameras was set up in one of these catchments. The spatiotemporal patterns of snow depth inside the forest and at the adjacent open field sites were recorded along with snow interception dynamics. Comparison of observed and modelled snow cover and canopy interception indicates that the new version of WaSiM reliably reconstructs the variability of snow accumulation for both the forest and the open field. The Nash-Sutcliffe efficiency computed for selected runoff events in spring increases from −0.68 to 0.71 and 0.21 to 0.87, respectively.