Application of morphotectonic indices for assessing active tectonics: A case study of Acheron river basin

Abstract

Rivers tend to alter the morphology of their bed and valley as a response to changes in their base level. The study of a drainage basin's tectonic activeness is very important. But especially in areas where rates of vertical tectonic movements are scarce, the morphometric analysis can be proved to be a very accurate method for assessing the effects of neotectonic movements on a drainage network. This method is easy to apply, as it does not require a lot of data. This study concerns the drainage basin of Acheron river in Epirus, Greece. In order to assess of river's response to active tectonic movements, a morphometric analysis was conducted, using a digital elevation model (DEM). Seven morphometric parametres and five geomorphic indices were calculated for the entire basin, as well as 9 sub-basins. Subsequently, each sub-basin was categorised into three categories regarding tectonic activeness (high-medium-low) for each index individually. The relative active tectonics index was also calculated, as the average of the aforementioned morphometric parametres and geomorphic indices. Based on that, each sub-basin was categorised into three categories regarding the overall tectonic activeness (low-medium-high). These results were compared with the drainage pattern and field observations, so as to gain insights on the tectonic activeness of the sub-basins and the entire basin of Acheron.