Episodes of climate change are responsible for profound reorganization of rates and spatial distributions of earth surface processes. In glaciated British Columbia the series of climate changes that occurred during the Quaternary have left a landscape characterized by a peculiar hierarchy of topographic anisotropies. Currently, fluvial and hillslope processes dominate the landscape, and are slowly reshaping these anisotropies. By means of extensive channel surveys, air photo interpretation, and GIS analysis we extracted slope-area transects along the main stem of drainage basins - area ranging between 1 km2 and 50 km2 - located in three different physiographic regions of British Columbia. Results display generalized process-form disequilibrium, where topographic signatures do not match with currently active geomorphic process domains. The landscape has not recovered yet from past glacial perturbations, accordingly, the combination of glacial legacies and the effects of ongoing earth surface processes generate a more complex geomorphic picture than that described elsewhere for unglaciated mountains. This emphasizes the importance of climatic and geomorphic history in interpreting contemporary landscape dynamics.
The Quaternary legacy in the organisation of contemporary geomorphic processes in forested mountain environments of British Columbia
BRARDINONI, FRANCESCO;
2004
Abstract
Episodes of climate change are responsible for profound reorganization of rates and spatial distributions of earth surface processes. In glaciated British Columbia the series of climate changes that occurred during the Quaternary have left a landscape characterized by a peculiar hierarchy of topographic anisotropies. Currently, fluvial and hillslope processes dominate the landscape, and are slowly reshaping these anisotropies. By means of extensive channel surveys, air photo interpretation, and GIS analysis we extracted slope-area transects along the main stem of drainage basins - area ranging between 1 km2 and 50 km2 - located in three different physiographic regions of British Columbia. Results display generalized process-form disequilibrium, where topographic signatures do not match with currently active geomorphic process domains. The landscape has not recovered yet from past glacial perturbations, accordingly, the combination of glacial legacies and the effects of ongoing earth surface processes generate a more complex geomorphic picture than that described elsewhere for unglaciated mountains. This emphasizes the importance of climatic and geomorphic history in interpreting contemporary landscape dynamics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
