A Study On The Variational Characteristics And Forecast System Of Human Comfort Degree In Xingtai Area

The development of human society has led to the acceleration of urbanization progress, and urbanization process could bring the problem of urban environmental meteorology, Urban Environmental Meteorology is an emerging interdisciplinary research field of meteorology. Under the trend of global warming, the probability of extreme weather and climate events greatly increases, and they add more influence on human’s survival environment. Climate is an important part of human living environment, in the evaluation of living environment and tourism resources, human comfort degree has gradually become one of the most important factors. It is drawing more and more attention. In this paper, different geomorphologic features were chosen to study the change of human comfort degree in Xingtai area. Based on surface meteorological data of daily average temperature, average relative humidity and average wind speed which are close to human comfort degree from1981to2010in six meteorological observatories of Xingtai, Lincheng, Nanhe, Ningjin, Nangong and Linxi, the temporal and spatial variation characteristics were analyzed. According to the chosen formula, the human comfort degree and its grade of six meteorological observatories were calculated, and then the variation of human comfort degree was analyzed. On that basis, the correlation analyses between temperature, relative humidity, and wind speed with human comfort degree were done, and then the mutation of comfort days and its change in different years were researched by Mann-Kendall (M-K) test. The change of human comfort degree in urban area and suburban country was compared by calculated winter Wind chill index (WCI) and summer Temperature-humidity index (THI), and the Pearson correlation coefficient between average temperature, average humidity and average wind speed with WCI and THI were analyzed. Finally, the detailed human comfort degree forecast system was developed. The results are as follows:(1) Nearly30-year data analysis shows the temperature which is closely related to human comfort degree has obviously increasing trend and the distributions of monthly average temperature appear single-peak pattern in every meteorological observatory. The average relative humidity which is also closely related to human comfort degree has seasonal change in order of summer, autumn, winter and spring (from largest to smallest), and it is lager in plain area than that in mountain area. The average wind speed which is also closely related to human comfort degree has seasonal change in order of spring, summer, winter and autumn (from largest to smallest).(2) The change of monthly human comfort degree has the same trend as monthly average temperature, and also shows single-peak pattern. Average annual comfort day (human comfort degree grade-1,0, and1) is about40%of one year. The number of cold uncomfortable days (human comfort degree grade-3) is about1/3of one year. Thermal discomfort days (human comfort degree grade3、4) concentrate on summer and show a gradually increasing trend. The number of cold uncomfortable days (human comfort degree grade-3、4) show a decreasing trend. The Pearson correlation shows that the temperature is the most important factor affecting human comfort degree. The comfort day has obviously increasing trend and the M-K test shows the degree of suitable living conditions is improving in Nangong and Linxi.(3) Compared by WCI and THI index between urban area and suburban country, urban area has more muggy weather in summer and less cold weather in winter, there exists obvious heat island effect. There is better correlation between WCI with average temperature and average wind speed, showing obvious wind-chill effect in winter. The temperature is the main factor affecting THI and the humidity has synergy effect to THI by temperature in summer.(4) Based on interpreting Numerical Weather Prediction (NWP) products, using inverse distance weighting (IDW) method, the European Centre for Medium-Range Weather Forecasts (ECMWF) fine grid NWP product data are interpolated to whole meteorological observatories in Xingtai. And then the detailed human comfort degree forecast system is developed. The preliminary application shows better result.The study can provide theoretical foundation and technical support for the development of Environmental Meteorology and Medical Meteorology forecast work and for the creation of the livable city in Xingtai area.