Impact of predicted climate change on landslide reactivation: case study of Mam Tor, UK

Global change is expected to result in worldwide increases in temperature and alteration of rainfall patterns. Such changes have the potential to modify stability of slopes, both natural and constructed. This paper discusses the potential effect of global climate change on reactivation of landslides through examination of predicted changes in rainfall pattern on the active landslide at Mam Tor, Derbyshire, UK. This landslide is of Pleistocene origin and is crossed by a road that is now abandoned. Damaging winter movement is known to occur when precipitation reaches both 1-month triggering and 6-month antecedent thresholds. Return periods for threshold exceedence is modelled statistically, and the climate change data from the UKCIP 2002 report (Hulme et al. 2002) is applied to this model. For the predicted changes in precipitation, it is shown that the instability threshold could decrease from 4 to 3.5 years by the 2080s for the medium–high climate change scenario. However, predicted temperature changes could influence the response of the landslide through increased evapotranspiration leading to a change in the triggering precipitation thresholds, and this will help counter the impact of changes in precipitation. Analysis of sources of uncertainty in the model has been used to establish the factors that contribute to the predicted changes in stability. Assessment of these factors can provide an indication of the potential impact of climate change on landslides in other areas of the UK.