Proglacial and Paraglacial Fluvial and Lacustrine Environments in Transition

Abstract

Geomorphology has two interlocking paradigms; the first is a process paradigm where there is a hierarchy of knowledge through the physics of a medium, the mechanics of process, to the landscape form; the second is a temporal paradigm from the history of the landscape, to the present condition, and with a prediction capacity. These are central to concepts of landscape transitions and landform assemblages. The paper explores landscape transitions occurring in proglacial and paraglacial environments based on the horizontal link of sediment transfer rather than on the traditional vertical division into glaciology, hydrology and periglacial geomorphology. In glacierized mountain areas the superimposition of transitions at different scales can readily be demonstrated within the regional landscape. Transitions may occur slowly, rapidly or instantaneously but their frequency of change will vary depending on the underlying cause of the transition. The concept of landform assemblages should integrate the ideas of process activity at different spatial, quantitative and temporal scales. Landform assemblages are therefore infmitely variable. The ways in which the concepts of transition and landform assemblages influence geomorphological interpretation is illustrated by reference to the glacierized environments of the southwest Yukon.