The evaluation of geological structures by the vector analysis of valley axes

摘要

Summary. The paper describes the methodology of evaluating geological structures by the vector analysis of valley axes. Both geological structures and valley axes were determined by the azimuth and the dip which corresponds with the angle of the slope in the selected catchment in the central Czech Republic. The determination of the dip of valley axes has formed a base for the quantitative classification of valley axes analogous to geological structures. The following five types of valley axes were distinguished: sub-horizontal, gently inclined, moderately inclined, steeply inclined and sub-vertical. The orientations of both the valley axes and the geological structures were evaluated by the construction of outline diagrams in the programme Spheristat. The directions of valley axes were compared with geological structures by the statistical relationship using the x~2-test. The directions of sub-horizontal valley axes correspond with the azimuth of foliations in contrast to the azimuth of joints in the model area. The evaluation of geological structures by the vector analysis of valley axes is practicable in all kinds of landscape.