Characteristics Variation of Human Comfort Index in Tibet Region

This paper analyzed the temporal and spatial distribution of human comfort index in Tibet region based on the observation at 38 meteorological stations from 1980 to 2009.Result shows that whatever the annual or seasonal distribution,the variation of human body index expressed decreasing tendency gradually from the southeast part to the northwest part of Tibet.The general comfortable areas were mainly located in the southern and southeast part of Tibet.The human body index presented increasing tendency in the past 30 years over Tibet region and it closely related with altitude,latitude,air temperature and relative humidity.Considering the number of comfort days,Tibet region were basically in cold or cool situation and it has fewer days of extremely cold or general comfortable.The number of uncomfortable days in grade 1 and grade 2 appeared decreasing tendency,but the number of uncomfortable days in grade 3,grade 4 and comfortable days in grade 5 displayed increasing tendency in the past 30 years.From the number of comfortable days for tourism,it was suitable for traveling during June to September in the northwest part of Tibet,May to September or October in the middle areas of Tibet region.The transition to the southeast part of Tibet,it was suitable for traveling during May to October,even can advanced to April.The number of suitable months and days for traveling indicated increasing tendency gradually from the north to the south areas.