Abstract
Long-term risk trend analysis for snow-related casualty cases in Niigata Prefecture for 46 winter seasons was carried out. Specifically risk and factor analysis of 1037 records of casualty cases in the most recent 16 winter seasons was conducted. The results are summarized as follows:
1. After the 1985-86 severe snowfall winter season, even though warm and snow-scarcity winter continued, the risk of snow-related casualty cases increased. On average, 127 persons suffer accidents, 16 of them fatal, in a winter.
2. After 1987, it could not find low frequency and high magnitude risk of fatal cases. but high frequency and low magnitude risk of injury cases is increased.
3. Casualty cases are classified into 7 categories: tumbling down from a height (64%), accidents involving rotary snow-plow operation (15%), falling snow/objects (11%) and so on. High fatality rates appear in the categories of falling into waterways and coming down with a disease, and to 70 years or older persons, and in the time between 19 pm and 21 pm.
4. 97 percent of casualty cases occurred in the area where 43% of the population lives. Especially, the personal risk rate in the mountainous snowy region is 1.8×10-5 person/yr.
5.The risk rate associated with meteorological conditions at the day becomes higher by lower temperature, and is particularly high when there is more than 1 meter snowfall rate for 3 days or 1.5 meters 7 days.
6.Comparing the 1980's and 1990's, the number of injuries to aged persons and younger persons is on the rise.
7.The risk of snow-related fatal accidents in the mountainous snowy region is almost equivalent to that of traffic accidents and 16 times that of occupational fatal cases.
