RECORDING OF SLOPE PROCESSES FROM HISTORICAL TIMES ON THE EXAMPLE OF TWO CLOSED DEPRESSIONS IN THE VICINITY OF JASIEŃ LAKE (NORTHERN POLAND)

Abstrakt

The authors of the article, based on field studies conducted within two closed depressions located to the east of Jasień Lake (northern Poland), attempted to identify periods of increase in the intensity of denudation processes. Hillslope sediments identified in depressions and material dating using 14C method enabled distinguishing two periods of intensification of the 108
slope processes. The first period fell on the sixth century and was synchronous with the beginning of the early medieval settlement phase in Pomerania. Increased flushing of hillslope material during this period could have been affected by increased humidity and cooling of the climate. The second recognized phase began in the fourteenth-fifteenth century, i.e. during the heyday of the village of Jasień and simultaneous deforestation process in order to acquire new areas for the development of agriculture. This phase was accompanied by the cooling of the climate, which could have led to the dilution of vegetation, which facilitated the movement of sediments on the slopes. It should be emphasized that in the case of both periods, the economic activity of man is considered the main reason for the growth of hillslope processes.