AN APPROACH TO ANALYZING THE VULNERABILITY TO ENVIRONMENTAL CHANGE IN CATCHMENTS IN SOUTHWESTERN NORWAY - RESEARCH DESIGN AND PRELIMINARY RESULTS

The modelled change in precipitation distribution and intensity warrant efforts to improve our understanding of the dynamics between geomorphology, climate, hydrology and society on the catchment level. This is particularly important for western Norway as this is where the most significant increase in precipitation is expected. The southwestern coast owes its topography to repeated quaternary glaciations carving out steep catchments in primarily hard Precambrian rocks and softer rocks of Paleozoic age. Following the non-linear retreat of the Fennoscandian ice sheet, the valley floors have been covered by glacial and glaciofluvial sediments of varying facies and mass wasting deposits. This provides an interesting setting with very different potential for landscape development depending on the geological history of the catchment. This presentation is a part of a larger project aiming to improve our understanding of how catchments respond to environmental change with particular focus on geohazards and hydropower potential.

In the current presentation, we outline an integrated approach to analyzing catchments in southwestern Norway, based primarily on remote sensing data, existing data (meteorological, hydrological) and collected field data. Here we present some preliminary results applying parts of the methodology. By using a DEM (lidar and photogrammetric) and derived products in conjunction with aerial photography and contextual information such as Holocene sea level change and glacial history, prominent landscape features are delineated and classified. Measurements of temperature and conductivity in springs estimate the surface and subsurface flow of water in the hillslopes. These measurements can then be compared to data in the instrumental record. As the hydrological properties of slopes of different compositions are measured and stored, these attributes can be generalized and applied to different landscape units in different catchments with similar properties. This involves the integration of different types of data acquired at different resolutions presenting some interesting possibilities and methodological challenges.