Geohazards and the urban environment

Abstract

AbstractRecent escalation of urbanization throughout the world has increased the attention to geoscience in the urban setting. In the urban context, earlier attention to routine engineering geology and hydrogeology investigations was later augmented by the introduction of thematic mapping and the erection of urban databases to support environmental assessments and land use planning. More recently, the role of the urban environment in exporting pollution regionally and globally, and the problems of degradation of the urban environment itself, together with the immediately surrounding area on which the urban community depends for resources, have attracted attention; as has the mushrooming of megacities which threatens disastrous environmental problems. In this paper, the aim is to review the geohazards that threaten the urban setting (using the term ‘geohazard’ in the broadest sense, i.e. both natural and human-made, and both intensive rapid-onset and slow-onset pervasive geohazards).To illustrate the extent of urban problems, the principal natural geohazards which threaten towns and cities, most of them of the intensive, rapid-onset type, are briefly considered. However, the emphasis is on the various human-made geohazards, most of them pervasive and of slow onset. Examples are cited of these human-made problems, all of which involve the interaction between human activity and natural processes. Details are given of some of the acute problems facing cities and towns, as well as urbanized regions.