Suchergebnisse

Abstract. Climate change is one of the greatest threats currently facing the
world's environment. In Norway, a change in climate will strongly affect the
pattern, frequency, and magnitudes of stream flows. However, it is
challenging to quantify to what extent the change will affect the flow
patterns and floods from small rural catchments due to the unavailability
or inadequacy of hydro-meteorological data for the calibration of
hydrological models and due to the tailoring of methods to a small-scale level. To
provide meaningful climate impact studies at the level of small catchments,
it is therefore beneficial to use high-spatial- and high-temporal-resolution
climate projections as input to a high-resolution hydrological model. In
this study, we used such a model chain to assess the impacts of climate
change on the flow patterns and frequency of floods in small ungauged rural
catchments in western Norway. We used a new high-resolution regional climate
projection, with improved performance regarding the precipitation
distribution, and a regionalized hydrological model (distance distribution
dynamics) between a reference period (1981–2011) and a future period (2070–2100). The flow-duration curves for all study catchments show more wet periods in the future than during the reference period. The results also show that in the future period, the mean annual flow increases by 16 % to 33 %. The mean annual maximum floods increase by 29 % to 38 %, and floods of 2- to 200-year return periods increase by 16 % to 43 %. The results are based on the RCP8.5 scenario from a single climate model simulation tailored to the Bergen region in western Norway, and the results should be interpreted in this context. The results should therefore be seen in consideration of other scenarios for the region to address the
uncertainty. Nevertheless, the study increases our knowledge and understanding of the hydrological impacts of climate change on small
catchments in the Bergen area in the western part of Norway.