The role of landslides in the evolution of a small mountain river valley (Polish Carpathians)

Abstract

In this work we describe the role of landslide processes in shaping river channels and the development of valley floors in 3 rd and 4 th order catchments in the Polish Flysch Carpathians. The main focus of the study was on the contact zone between the landslide system and the river channel, where it has been shown that 30.2% of the length of the river network are affected by landslides. Research shows that 93% of landslides have some form of contact with the river system. Research further shows that the most common contact types in the study are point and area types according to the Korup classification. The most common impacts of landslides on the river channel are riparian and partial occlusion types. Landslides very often cause complete or partial displacement of the river channel, which frequently leads to the blockage of flow, which in turn creates landslide lakes, followed by accumulation zones. The effect of such events is the transformation of the longitudinal profile of the river and the intensification of erosive processes in the contact zone and downstream. Increased activity of erosive processes can lead to the activation of landslide processes, including on the opposite slope.

Recent advances on geomorphology of the Gorce Mountains, the Outer Western Carpathians – state-of-the-art and future perspectives

“…The relation between landslides and stream channels was analyzed in seven catchments in the Gorce Mts. (Caputa & Gorczyca, 2020). The percentage of the area affected by the landslides was between 5.5-43% in these catchments, so it differs very strongly.…”

“…The percentage of the area affected by the landslides was between 5.5-43% in these catchments, so it differs very strongly. Influence of the landslides on the channels in the whole Polish Carpathians (30 catchments) is defined as seven types: occlusion, partial occlusion, riparian, cutting colluvium, obliteration, blockade, buffered (Caputa & Gorczyca, 2020).…”

Landslide type inference based on statistical analysis of a high-resolution digital elevation model in Gorce National Park, Poland

“…Most extensive landslides are associated with wet interglacial and Holocene periods. In the Polish Carpathians, landslides are mainly triggered by antecedent precipitation and low-magnitude earthquakes 8 , 9 , and 93% of landslides have some form of contact with a river system 10 . In relation to the geological structure, landslides are often developed due faults, joints and mechanical contrast of sandstons and shales 11 .…”