Abstract

Landslides can be mapped for purely academic reasons to understand their nature and properties, or for engineering purposes because they constitute a hazard to an existing human activity or a proposed development. The scale of the mapping to be carried out will be influenced by the requirements of the investigation. For engineering investigations large-scale mapping (>1:10000) is generally the most appropriate whereas for academic studies smaller-scale mapping can be just as valuable as it can reveal much about the role landsliding has in overall landscape development. In this paper three examples of mapping landslides at different scales are presented and the implications for the mapping procedures employed are explored. These examples are: (1) large-scale mapping of an active landslide affecting a road and mobile home site on the SW coast of the Isle of Wight, UK; (2) medium-scale mapping of landslides in the proximity of a river capture site in SE Spain; (3) small-scale mapping of large coastal landslides in northern Chile and the implications for mass sediment transfer along an active subduction margin. All three mapping programmes had a clear focus and intent but the method employed varied with the purpose of the investigation and the scale of the mapping that was carried out. It was concluded that it is important for any landslide mapping programme to have clearly identified objectives from the outset if time, and money, is not be wasted. However, even in site-specific investigations it is imperative for landslides to be seen in the wider context of their geomorphological situation with their role in landscape development assessed so as to understand the likelihood and potential magnitude of any hazards.