This paper analyses the linkage between slope wash and sediment and solute export from the Stara Rzeka foothill catchment. Transport of sediment on slopes and its supply to the stream channel vary in time and depend on morphology and agricultural use of the area. Three thresholds important for morphodynamics in a foothill catchment have been established as well as the role of slopes and valley bottoms in the supply of suspended matter to stream channels. When the first threshold is exceeded, occasional transport of material on a particular slope is initiated. When the second threshold is exceeded, local erosion is triggered on a slope. When the third threshold is exceeded, general transport of material on a slope takes place and is deposited in the valley bottom. When the second threshold is exceeded, the linkage between the slope and the channel is local. When the third threshold is exceeded, the connection between the two systems is general but still the majority of material transported from the slope is deposited on the footslope proluvial plains and in flat valley bottoms.In the Stara Rzeka foothill catchment, chemical denudation is dominant. However, the proportion of solute and sediment export is significantly larger in its subcatchment. This indicates that proluvial plains impede free sediment flux from the watershed divide to the channel and also that the solute transported by streams comes from the whole area of the catchment, while the source of the sediment is channel erosion.

This paper examines the influence of plant cover and land use on slope-channel decoupling in the Stara Rzeka Stream catchment (22Ð4 km 2 ) and its subcatchment Dworski Potok Stream (0Ð3 km 2 . The Stara Rzeka catchment is situated in the marginal part of the Carpathian Foothills and is characterized by a relief of low and medium hills. The catchment is used for agriculture but unlike other foothill catchments, it has a relatively extensive unfragmented area of forests (41Ð3 per cent). Grasslands and pastures (13Ð8 per cent) are mainly along the broad and flat valley floor. In the cultivated area (38Ð5 per cent) of the northern low hill part of the catchment, the fields are long, narrow and separated by boundary strips. They stretch from the hilltops to the valley bottom and are traditionally ploughed along the slopes.The research into slope wash was carried out at six sites downslope (August 1989 to October 1990) and on experimental plots (1989)(1990)(1991). Transport of suspended matter was determined in the channels of the Stara Rzeka and Dworski Potok Streams (1987Streams ( -1991.The results show that transport and export of the material on the slopes depend on the morphology of the slope and on the agricultural use of the area. The mosaic of fields which are used differently makes the soil wash process very intensive only if the slopes are ploughed and unprotected by a dense cover of vegetation. The material displaced is mostly accumulated at the foot of the slopes or at the bottom of the valley. Footslope areas and flat valley bottoms covered with grass function as a barrier separating the slope and the river bed. These features generally negate the transfer of slope-originated material to the bed of the stream.

No abstract

The paper presents activity of contemporary geomorphic processes in the Polish Carpathians, taking into account human impact on relief transformation in the past several centuries. Landsliding in the flysch Carpathians is a principal process in slope transformation, posing the most serious threat to man, both in the mountains and the foothills. On the other hand, unsuitable housing on slopes initiates mass movements, frequently with catastrophic consequences. Land use changes, in particular deforestation, have over the past 200 years fostered intensive slopewash and linear erosion, with this playing an important role in shaping foothill relief. Following changes in land use and channel regulation initiated at the beginning of the 20th century, a tendency to river bed deepening prevails. Moreover, floods, and not only extreme instances, continue to pose a threat to man, with their effects enhanced by housing in floodplain areas. A tendency consisting in the reduction of arable land and an increase in grassland and forest area, observed over the past two decades, will lead to a gradual limitation of slope-wash and wind erosion as well as a simultaneous increase in linear erosion on slopes and river bed deepening.

No abstract