The spatial and temporal distribution of the sediment accretion upon a young (less than 100 years old), predominantly inorganic back barrier salt marsh has been studied based on leveling in 1973, a re-survey in 1998 and observations from 1931 to 1954 of the same area. The surface of the back barrier of Skallingen is not sloping gradually, from the dune ridges to the marsh edge, but is separated into three zones: an inner and an outer marsh at a level of about 1 m DOD (Danish Ordnance Datum), and a lower section in between at 0.9 m DOD. During the last 25 years the rate of sedimentation has been 3 mm a 1 on the inner and outer part and about 2 mm a -1 on the lower. The accretion on recently developed salt marsh areas along the marsh edge has been 8 mm a -1 , a rate which looks characteristic for new marsh building on Skallingen as early investigations in the 1930s indicate a similar magnitude. This relatively high rate may be partly a result of sediment imported by sea ice rafting. Different methods used to measure the rate of sedimentation (marker layers, profiling and 210 Pb isotope dating) all agree quite well. The average rate of sedimentation since 1931 on established marsh surfaces has almost been uniform, 3 mm a -1 which is well above the average sea-level rise of 1.3 mm a -1 during the last century. However, concerning the last 25 years, the hydrographical conditions have change dramatically. There has been an increased frequency of inundation, more storm surges, and the sea-level rise has increased to 4.2 mm a -1 . But the accretion rate has not change, it is still 3 mm a -1 . No evidence of stagnation or degradation of the salt marsh, however, has been observed yet.
Rasch, Morten, Jørgen Nielsen & Niels Nielsen: Variations of Spacings between Beach Cusps discussed in relation to Edge Wave Theory. Geografisk Tidsskrift 93:49–55. Copenhagen 1993. Variations in cusp spacings of beach cusp systems have been examined, and the conclusion is that the apparent regularity of the spacings is not always real. Established edge wave theory predicts equal cusp spacings, and accordingly, the theory needs to be improved or alternative theories accepted. Field measurements of beach cusp formation under reflective morphodynamic conditions confirmed that established edge wave theory was not always capable of explaining beach cusp formation. The beach cusps grew from small irregularly spaced mounds, and the regularity of the cusp spacings seemed to increase during beach cusp development. Correlation between observed average cusp spacing and the average cusp spacing predicted on the basis of edge wave theory might suggest that edge waves were the initiating mechanism causing beach cusp development. However, the observed water circulation pattern and the variations of the individual spacings between the beach cusps were both contradictory to existing edge wave theory.
Abstract An automatic meteorological station has been operating at the Arctic Station (69°15'N, 53°31'W) in West Greenland since 1990. This paper summarizes meteorological parameters during 1997, including snow and sea ice cover, ground temperatures and active layer development, and presents comments on the local permafrost thickness. In March 1997 an automatic climate and water balance station was established on the peninsula Skallingen, 55°30'N, 8°15'E. The data can be retreived by a cellular phone and a modem. The station and selected data are described. Abstract The present paper sketches out a method for a quantitative description of landscape structure, which can be used for biologically optimal landscape management. The approach suggested is based on a landscape ecological framework and emphasis is laid on spatial characterisation of the landscape. It aims at supplementing conventional landscape descriptive parameters of biological importance, which are derived from a range of empirical data, with a spatial characterization. The method is implemented in a vector-based GIS (ArcView) and allows quantification of landscape structure in different landscape types. Suggestions to further development of the method are discussed.
