Factors affecting risk from natural hazards, Kullu Valley, Himachal Pradesh, India

Natural hazards are natural phenomena that produce net negative effects on people and their livelihoods and may include processes of flooding, landslides, debris flows and rock fall. Mountain regions are particularly susceptible to the occurrence of natural hazards owing to the frequent juxtaposition of human-built infrastructure with the release, transport or deposition zones of natural erosion processes. The Kullu Valley served as the study area for a comprehensive examination of the effects of changes in land use/cover, climate and seismic activity on the exposure of people and their livelihoods to risk posed by natural hazard processes between 1972 and 1999. Through field work, GIS-based land use/cover change and run-out zone modeling, a review of current literature and historical data, an examination of a 98-year climate record and 122-year seismic record, and interviews with local inhabitants it was established that land use/cover change in the deposition/inundation zones accounts for most of the apparent increase in risk due to natural hazard between 1972 and 1999.; Further analysis found little evidence to support the theory that much of the Himalaya is undergoing rapid deforestation leading to noticeable changes in the frequency and magnitude of slope erosion and denudation processes. Forest cover, climate and earthquake activity, the main factors influencing the material activity of slope processes and floods, have not changed appreciably in the study area over the past century.; The intended globally-applicable nature of the techniques developed and used here requires more research be carried out in order to validate the deposition model with data from other mountain areas. The GIS-based framework provides a convenient and flexible approach to the cataloguing and analysis of any spatially referenced data related to the occurrence, activity and change of natural hazards in any mountain area.