Relationships in Geomorphology

In many respects, the theory of the normal cycle of erosion remains an unproven one, although it was based on extensive and detailed field observations of landforms in the eastern US and Europe, it remained assentially a descriptive conceptual model. The most notable objections came from the disbelief that such rapid uplift could occur to initiate a new cycle and that examples of the end-point could not be identified at or near any current base level of erosion. The objections were strongly expressed, elaborating on slope form and erosion, were controlled primarily by varying rates of uplift and the balance achieved between the rate of down cutting of a valley floor and the angle of the valley – side slope. Slopes were thus independent of a cycle but were in a state of dynamic equilibrium controlled by the energy of a river in relation to the rate of uplift of the land surface.

This idea was later embraced through landscape evolution – the end point of which was a land form termed a pediplain. A work on the erosional development of streams and their drainage basins and a quantitiative approach in which landforms would be measured and erosional processes analysed was put forward. Meanwhile considerable work had been initiated on the mapping of slopes and the morphometric analysis heralded in a new thinking which was to establish geomorphology as a quantitative science. Other developments in progress was remarks on a number of morphogenetic regions characterized by differeing climatic controls based on mean annual temperature and rainfall in which frost action, chemical weathering, mass movement, wind action and pluvial erosion all played a part. Interest in climatic geomorphology did initiate a number of more detailed studies of weathering and erosional processes operating in differing climatic regimes through time.

Explanations of slope form and slope processes were also a feature of shift towards a more thorough interpretation of the role of processes rather than structure or time in landscape studies. In Britain relationships were explored interlinking soils, regolith formation, denudation and slope form. A further systematic approach to the topic was presented, examining slope development through time, soil and rock instability, surface and subsurface erosion and rates of operation and formation as applied to different climatic regimes.

The “final affair” is that with the systems approach in which, the move towards quantification inherent in the empirical work and the shift away from descriptive denudation chronology elsewhere represented the attractive “chemistry” which pulled geomorphology into this new liaison. Systems theory was seen as providing a methodology around which all aspects of physical geography could unite and in so doing join the mainstream of scientific progress. In some respects, geomorphology was the last branch of physical geography to become attracted to this new thinking. Thus morphological, cascading, process response and control systems were all defined and exemplified, which in turn generated a plethora of further research in nearby all aspects of geomorphology, which had by now firmly nailed the process flag to its mast. The systems approach is furthered by an interdisciplinary convergence on environmental matters. The socio-economic aspects are integrated with physical and biological theory and in so doing a range of environmental matters are spawned. Many applied aspects of hydrology and fluvial geomorphology were addressed and the relationships across “the divide” between physical and human geography were discussed. In some respects this contributed to the literature of physical geography as well as heralding the rise of environmetal concerns which were to establish themselves onwards.

The progress and control that process studies exerted continued, increasing the fragmentation of the branches of geomorphology. There were even accusations that process orientated geomorphologists had “Lost the Plot” and forgotten that the main purpose of process studies was to explain the origins of landforms. Neverthless, the trend is ongoing and there remains considerable division between the reductionist approach and those who see processes as either an essential part of an over all picture of landscape evolution or as a necessary underpinning to applied studies which attempt to address the role of human influences on natural systems.


References:

King, L.C., 1950: A study of the world’s plainlands: a new approach in geomorphology quarterly journal of the Geological Society of London

King, L.C., 1953: Canons of landscape evolution, Bulletin of the Geological Society of America

Tricart, J., and Cailleux, A., 1972: introduction to climatic geomorphology; translated by C.J.K de Jonge. Longman, London

Chorley, R. J. and Kennedy, B. A., 1971: Physical Geography: A systems approach, Prentice Hall, London

Chorley, R. J., 1969: Water, Earth and Man, Methven, London