|The Impacts of Opencast Mining on the Rivers and Coasts of New Caledonia (UNU, 1984, 53 pages)|
Mineral exploitation, especially of nickel and chromium ores, and to a lesser extent of iron, cobalt, manganese, and coal, has been the essential basis on which the economy of New Caledonia (an Overseas Territory of the Republic of France) has developed during the past century. Within this period the production of nickel from New Caledonia has represented a significant proportion of world nickel production, exceeded only by that of Canada and, at times, by that of the Soviet Union. Extraction of nickel and iron ores by opencast mining has been extensive in New Caledonia, and, as many of the sites where these ores occur are on hilltops, there has been a major impact on the island's landscape. Mining waste generated from opencast hilltop workings has spread down slopes into bordering valleys, into river channels, and thence to the coast, in some cases filling in river mouths, augmenting deltas, and modifying the sediments and ecology of the nearshore areas.
Our aim in the present monograph has been to document the extent of this landscape modification in terms of the history of mining in New Caledonia and of economic factors that have influenced its development, and fluctuations in its intensity. The first chapter describes the environmental context, with special reference to geomorphology. The second reviews the history of mining activity in economic terms. The third examines each of the major river catchments of New Caledonia and traces the extent and impacts of mining activities, and the fourth considers mining in terms of landscape management, outlining some possible developments in the future.
Within the scope of such a review, we can do no more than indicate the geomorphological, sedimentological, and ecological consequences of mining and the dispersal of mining waste materials in New Caledonia. Our aim has been to present the overall picture. Detailed, local studies and assessments must follow.
We are grateful to the United Nations University, whose project on coastal resources management focused attention on coastal environments in New Caledonia; to the Office de la Recherche Scientifique et Technique Outre-Mer in Nouméa, which supported field research and documentation; and to the Société Métallurgique Le Nickel (SLN), especially MM. Le Goff and Cheyrezy, who provided permits and information. We also thank a number of colleagues, including Teh Tiong Sa of the University of Malaysia, Kuala Lumpur, for discussions and scientific advice; M. Philippe Ribère, photographer of the ORSTOM Centre in Nouméa; and Mr. Robert Bartlett and Miss Wendy Godber, Department of Geography, University of Melbourne, for the preparation of maps, diagrams, and photographs.
Eric C.F. Bird
Jacques A. Iltis