Ocena przydatności zdjęć lotniczych w badaniach osuwisk na przykładzie Beskidu Śląskiego i Małego

Abstract

Distribution of landslides on slopes of the flysch Carpathians is different and irregular. There are areas in which more than 50% of slope surface is modelled by landslide processes. The Beskid Śląski and Mały which are built of flysch (sandstone and slates alternating) belong to such areas. The aim of the work to show possibilities of air photographs use for mapping and analysis of landslide areas dynamics. Panchromatic air photographs of these areas were watched with the help of the stereoscope and then with the help of LUZ projector boundaries of the landslides were marked on topographic maps at a scale 1:10 000. Such cartographic material allowed interpretation of forms and structure of landslide areas. Interpretation of air photographs may be of great importance in researches on landslide processes. This method, allows to mark boundaries of landslides more precisely, to make a detailed map of a landslide and allows to make analytic calculations concerning dynamics of landslide relief and in the result, the quantity control of processes is possible. It is also possible to evaluate changes in slope relief on large areas in a short period of time. On the basis of information obtained from the air photographs interpretation it was stated that boundaries of landslides, course of landslide edges and scarps can be easily noticed because phototones are changed in these places. Big landslide ridges can be also easily seen as well as depressions inside landslides and erosional dissections. New slides within old forms may also be indentified. This new method in comparison to the traditional landslide mapping shows that landslide areas are larger and that niches which course is accordant to joint fissures and tectonic zones predominate in their morphology.