The Welfware Of Climate Comfortable Period In Mainland China:Its Spatial Pattern And Evolution

The welfare of climate comfortable period is an important type of climate welfare, it considers the climate comfortable period and distribution of population, is a typical characterization of climate change. The research of climate comfortable period is to evaluate an area whether it is comfortable or not and to quantify the length of climate comfortable time by climate comfortableness indices. Recent years, under the global warming, different regional response and changes of climate comfortableness and climate comfortable period have occurred, leading to different changes in welfare of climate comfortable period, while demographic changes will further strengthen the changes in welfare of climate comfortable period, and therefore nationwide research should be carried out on the mainland about welfare of climate comfortable period.This paper firstly presents the empirical model and rational model emerged in the climate comfort research briefly, introduces the Temperature Humidity Index in empirical model in detail, including its origin and modified course. According to the special climate condition of Chinese Mainland, this paper conducts relevant improvement on the evaluation standard of THI on the basis of daily observation data (such as temperature, wind speed, relative humidity and sunshine duration, etc.) of recent 30 years (1981-2010) from 824 basic and benchmark meteorological sites. The index is divided into seven classes of torrid, hot, warm, lukewarm, cool,cold, glacial to fit the daily feelings of Chinese residents. WEI is another representative empirical model. This paper figures out the average climate comfortable period and the uncomfortable period of hot/cold by the observation data of recent 50 years (1961-2010) with the combination of this two models. Besides, it combines the result with demographic census (local population) to calculate the climatic comfortable period’welfare of population. The responding mechanism on climate comfortable period of population and evolution of climate comfortable period’welfare can be analyzed through the dynamic data of the third, fourth, fifth and sixth demographic census. The main conclusions are:1) The annual average climate comfortable period and discomfort period of heat has been increasing while the discomfort of cold is reducing.2) The distribution of climate comfort period welfare showing that the northwest is less than southeast, spring, summer and autumn days are respectively taking up a 1/3 of the totle days, least in winter; uncomfortable period losses of cold are mainly concentrated in the winter, accounting for 81% of the totle days; discomfort period of heat concentrated in the summer.3) From the third to sixth demographic census climate comfortable period’welfare increased 6.4 days, uncomfortable period losses of cold have reduced 5.8 days, uncomfortable period losses of heat have increased 1.2 days. The areas where chemotaxis index increased are mainly located in the northwest and the southeast coast and the Yunnan-Guizhou Plateau except for the Himalayas region.