The relationship between relative height and microrelief: three case studies from Northern Finland

Abstract

Three different drainage basins were studied with the aid of a quadratic grid consisting of 3439 data points. For each areal unit (4 km²) the relative height was calculated as the difference between the highest and the lowest point, and the microrelief, i.e. the variability in relief, was established by counting the numbers of contour lines at 10 m intervals intersecting the circumference of a circle 2 km², drawn in the centre of each data point. The material was analysed cartographically and statistically.

Relative heights provided a fairly true picture also of the variability in the relief of some areas, while others were obviously misrepresented.

The difference was greatest in the areas with the smallest relative height values, diminishing then gradually, and disappearing entirely at some point in the range 30–80 m depending on the area concerned. The figures of 30 m and 80 m emerged as two of the most appropriate boundary values for a relative height classification suitable for Northern Finland. In making conclusions the microrelief density (Mrd) values, as determined from the in­terrelation between the microrelief and corresponding relative heights, proved to be of practical use.