Deciphering the effect of climate change on landslide activity: A review

Increased landslide activity is commonly listed as an expected impact of human-induced climate change. This paper examines the theoretical and empirical bases for this assertion. It identifies the mechanisms by which climate can induce landsliding and examines the manner in which these mechanisms may respond to changes in a range of climatic parameters. It is argued that inherent limiting stability factors, which vary with different terrain conditions and landslide types, ultimately govern the nature of response to changing climate. Several modelling approaches are evaluated on the basis of their potential to predict landslide response to climate projections. Given reliable input data of appropriate form and resolution, the existing slope stability, hydrological, and statistical models are for the most part capable of yielding useful prognoses on occurrence, reactivation, magnitude and frequency of landsliding. While there is a strong theoretical basis for increased landslide activity as a result of predicted climate change, there remains a high level of uncertainty resulting from the margins of error inherent in scenario-driven global climate predictions, and the lack of sufficient spatial resolution of currently available downscaled projections. Examples from New Zealand are used to illustrate the extent to which changes resulting from human activity have affected slope stability. Changes resulting from human activity are seen as a factor of equal, if not greater, importance than climate change in affecting the temporal and spatial occurrence of landslides. (C) 2010 Elsevier B.V. All rights reserved.