Spatial and temporal evolution of co-seismic landslides after the 2005 Kashmir earthquake

Abstract

Large earthquakes in mountainous regions often trigger widespread landslides, some of which remain active for years to decades. This study has evaluated the spatial and temporal evolution of the 2005 Kashmir earthquake-induced landslides using pre-earthquake and post-earthquake landslide inventories. Temporal landslide inventories were developed from the SPOT satellite images, using the visual image interpretation supported with field validation. It is observed that after the earthquake, the landslide area and number showed a surge, however, decays in the subsequent years. The rate of decline in the landslide area was relatively slower until 2010, however, it dropped considerably during 2010–2018. The spatial variation of the landslides was traced and analyzed to classify them based on the activity. The temporal evolution of the landslides was compared with the geology, earthquake triggering fault and topographic attributes of slope, aspect, and elevation, to evaluate their influence on the distribution of landslides. The landslide inventories were related to the major triggering factors including rainfall and earthquakes, to determine their impact on the temporal dynamics of the landslides. Regeneration of vegetation is analyzed using the temporal NDVI images as one of the drivers for the decline in the landslide area. The knowledge of temporal dynamics of landslides and their major contributing factors shall assist to understand their triggering mechanism and effective mitigation measures.