DEM-based directional statistical examination of linear features: the case study in Bukk Mountains (NE Hungary)

Analysis of linear features such as faults, valleys, interfluves, and escarpments is a commonly used method in structural morphologic and structural geologic research. The aim of our study was to investigate the relationship between the linear features by directional statistical analysis, and we also examined the applicability of this method in a research area with a complex geological structure. The study area was the Bukk Mountains (NE Hungary) and its two catchment areas. The analysed features (drainage network, lineaments and dominant aspect) were derived from a DEM. As a result of the research, we found that in the Sajo catchment, the direction of lineaments does not coincide with the direction of the valleys and structural elements, nor the dominant aspect, while in the Tisza watershed, the orientation of the main structural features notably differs from the direction of the other 3 feature sets. In our opinion, this finding can be explained in three possible ways. The first possibility is that the applied method does not provide reliable results in a geologically complex area. The second explanation is that regional structural processes may affect drainage network evolution and the dominant aspect. The other explanation is that there may have been unknown structural elements in the research area, which affect the recent geomorphological settings and processes. The results draw attention to the fact that besides the unmapped faults, there might be other factors affecting geomorphological processes (e.g., resistance to denudation of different rock types, microclimate), which have not been taken into account so far. The research was based only on directional statistical examinations; further geological and geophysical analyses are required to prove the existence of these hypothetical morphotectonic features.