Integrated risk assessment of snow disaster over the Qinghai-Tibet Plateau

摘要

After analysing systematically formation mechanism of snow disaster (SD), this study revealed spatial-temporal characteristics of historical disasters, snowfall events, disaster-formation environment, livestock overload, vulnerability of livestock and adaptability, finally evaluated integrated risk index (IRI) of the SDs over the Qinghai-Tibetan Plateau (QTP) using ArcGIS method. Over the past more than 50?years, the recorded large scale SDs occurred 238 times. Overall, the large scale SDs decreased, yet the small scale SDs increased in frequency. Particularly, the year of extreme snowfall event’s occurrence did not correspond to the large scale SDs, in which a serious overloading rate with high livestock density is the key driver of the SD formation. The regions at higher IRI are mainly concentrated on mid-eastern and southwestern TP and appear a contiguous risk belt from northeast to southwest. Thinking about snowfall events and overload rate influencing mainly SD risk, it is necessary to improve forecasting and monitoring level of snowfall and snow cover extent, increase forage reserves, control strictly overload rate, implement livestock and grass balance strategy and enhances the scale of cattle and sheep housing and other infrastructures.