Human influence in geomorphology A2 - Vitek, John D

Abstract

ABSTRACT The human influence in geomorphology has a long history, and major contributions have, for example, been made by Shaler, McGee, Gilbert and Marsh. However, in the last two decades concern with global environmental change has brought the role of anthropogeomorphology into sharper focus. Global warming, if it occurs, will have important implications for many geomorphological processes and phenomena as a result of the direct effects of warming, as a consequence of other related climatic changes (e.g. precipitation change) and as a result of climatically moderated changes in major geomorphologically significant variables (e.g. vegetation cover). Large uncertainties exist with respect to such matters as hydrological response, the frequency of tropical cyclones, the speed and degree of permafrost degradation, the response of glaciers and ice caps, the extent of sea level rise, the reaction of beaches to rising sea levels, and the state of wetlands, deltas and coral reefs. Other human activities may serve to compound the effects of global warming on geomorphological processes. Given the uncertainties of so many of the environmental changes, there is a great need to obtain a greater understanding of the rates and mechanisms of landform response. Geomorphologists need, inter alia, to establish long-term study sites that will generate base-line data, to monitor the location and rate of change using sequential cartographic and remote sensing materials, to determine information on natural background levels and long-term trends by means of data gained from cores, to gain a more profound understanding of the operation of geomorphological systems particularly with regard to sensitivities and thresholds, and to appreciate the consequences of deliberate manipulation of environmental systems by humans.