Characterization and comparison of landslide triggering in different tectonic and climatic settings

Abstract

International audienceThe spatial and temporal distributions of landslides in six catalogues are analyzed in order to better understand landslide triggering mechanisms. The six landslide catalogs are New Zealand, Yosemite (California), Grenoble (French Alps), Val d'Arly (French Alps), Australia, and Wollongong (New South Wales, Australia). Landslides are clustered in time for all catalogs. For New Zealand, Yosemite, Australia, and Wollongong, the frequency of landslides varies between 1 and 1000 events per day and is well fitted by a power law: there is no characteristic scale for daily rates. When the large rates of daily landslides are known to be rain or earthquake triggered, our results suggest the same triggering may hold for the small daily rates. Earthquakes are found to trigger landslides for the New Zealand, Yosemite, and Australia areas at distances as large as 20 times their fault lengths. There is no evidence of landslides triggered by earthquakes for the three other catalogs. Small M ≤ 4 earthquakes have little influence on landslide triggering, if any, for all catalogs. For New Zealand, Yosemite, Val d'Arly, Australia, and Wollongong, the number of landslides per month is significantly correlated with monthly rainfall. A correlation with temperature is found only for Grenoble and New Zealand. Landslide triggering (strong clustering in time and space) is more important in New Zealand than in Grenoble, probably because the forcing (seismicity and climate) is stronger in New Zealand than in the French Alps but possibly also because of a high sensitivity to landslides in New Zealand. We suggest that intensity of clustering in space and time can be used to assess the importance of landslide triggering and the processes responsible for triggering

Supervised Method of Landslide Inventory Using Panchromatic SPOT5 Images and Application to the Earthquake-Triggered Landslides of Pisco (Peru, 2007, Mw8.0)

“…Most studies have therefore been performed at a basin scale (typically 50 km 2 ) for rain-induced landslide inventories (e.g., [20]). In case of co-seismic landslides, the distance affected by landslides can be as much as 10 times the fault length for small earthquakes (Mw < 5) and 3 to 5 times the fault length for larger earthquakes [32]. That is, for an Mw 8.0 earthquake, landslides can be triggered up to 600 km away from the source.…”

Hydrology of the Upper Indus Basin Under Potential Climate Change Scenarios

“…The susceptibility modelling is based on a statistical logistic regression analysis (Atkinson and Massari 1998;Bell 2007;Van Den Eeckhaut et al 2006). First the current susceptibility was investigated.…”

“…Main triggers of landslides are extreme precipitation, snowmelt and seismic activity (e.g. Tatard et al 2010;Wieczorek and Glade 2005). Usually susceptibility maps are elaborated based on data from past events, serving as key to the future .…”

“…Therefore developing landslide susceptibility maps for different climate change scenarios is a challenging task. For this purpose precipitation is taken as an important proxy (Tatard et al 2010), since heavy rainfall events have been recognized as a major triggering factor in the study area (Remaître et al 2013;Schwenk 1992). Also damage reports in the building ground register (BGR) of the Geological Survey of Lower Austria refer to rainfall as a predominant triggering factor in that region (Petschko et al 2010).…”

New Zealand’s National Landslide Database

“…This information is helpful to land-use planners, policy makers and network operators in their managing of the landslide hazard and its associated environmental impacts. An example of use of data from the database can be found in Tatard et al (2010).…”