Land-use changes and longer-term human–environment interactions in a mountain region (Sudetes Mountains, Poland)

Long-term socio-economic changes in the mountain communities, best documented as land-use changes, have been reflected in alternating functioning of the environmental system in the upper valleys in the Sudetes Mountains. The main role that human activity played on morphogenetic processes was to intensify or to weaken the linkages between hillslope and river systems. All stages of environmental change as a result of increasing or decreasing human impact, are easily recognisable in the area, both as human-made landforms and as sediment records. Therefore they provide archives of past and present human activities, allowing for the reconstruction of morphogenetic processes in the past. Detailed sedimentological and geomorphological analyses, along with studies on archival documents, topographic maps and aerial photographs from various periods, reveal many local variations, even within one small drainage basin. Occasionally, human impact might be of the same type and intensity in the entire catchment, but coeval environmental records, for example the thickness of colluvial or alluvial sediments, may differ substantially. The role of local topography (hillslope and valley length, hillslope gradient and microrelief, etc.) considerably influences sediment transfer and depositional processes. Hillslope–channel coupling is of importance as only in some places transport and sediment export from the catchment was favoured. In other places, local topographic conditions favoured sediment storage, limiting transport distance. Human impact turned out to be more important and much more widespread than previously assumed. Despite fewer human-induced sediments in the upper valley reaches, these are actually better archives for reconstructing the linkages between land-use changes and hillslope and channel response. Small-size catchments in the upstream parts of the study area are therefore suitable areas for reconstructing, assessing and quantifying past morphological human–environment interactions.