Geomorphic connectivity within abandoned small catchments (Stolowe Mts, SW Poland)

Studying 5 small catchments (0.6-2.7 km(2)) located in the central part of the Stolowe Mountains (SW Poland), which are partly or totally abandoned, has revealed the substantial changes of connectivity within the catchments. Field investigation (geomorphic mapping, morphometric analyses) and GIS based analyses of historical data show that slope-channel coupling is much less efficient than in the past, mainly due to the decrease of unpaved road network, especially roads linked directly with streams. Also land-use change with considerable loss of arable land does not support erosion from slopes. The general direction of geomorphic change due to depopulation and lack of maintenance of anthropogenic features tends towards higher stability and lower efficiency of morphological processes, connected with a sustained decrease in slope-channel coupling. This tendency is evidenced by relict landscape features (e.g. road gullies, abandoned roads) formed in the period of more intensive land use, for which higher dynamics of the morphogenetic system may be inferred. The evidence of contemporary erosion and mineral material transport is very local and spatially limited to a few roads which are still in use. Sediment transfer is additionally slowed down by the presence of numerous anthropogenic barriers within slope and valley-floor domains. Even though their total impact may seem only local and negligible at the catchment scale, their contribution to increase the diversity of morphological processes is significant. Especially the neglect of hydrotechnical constructions enhances trapping of material within the catchments. (C) 2013 Elsevier B.V. All rights reserved.