D23 Two case studies documenting spatial distribution of landslides – UCAM-DES

The following data sets have been acquired:

9,000 landslides in the western Southern Alps of New Zealand. Data set is complete for landslides larger than 5×10³ m². A subset of 3,500 landslides is complete for landslides larger than 1×10³ m². Most landslides were triggered by precipitation.

4,500 Landslides in the Finisterre Mountains of Papua New Guinea. One subset (~1,000 events) represents rainfall-triggered mass wasting. Another subset (~3,500 events) contains earthquake-triggered landslides. The latter shows distinct clustering of landslides around ridge crests and slope toes. The former shows uniform distribution of landslides across hillslopes.

22,000 landslides in the Central Mountains of Taiwan. These landslides were triggered by the 1999, M7.6 Chi-Chi earthquake. The spatial distribution of mass wastage shows strong topographic and lithologic controls. Additional data sets have been acquired for typhoon-triggered landslides after 1999. Rates of mass wasting for given precipitation events have increased dramatically after the Chi-Chi earthquake. River gauging data is used to constrain the spatial and temporal patterns of removal of seismically-generated debris from hillslopes.