Abstract:

Based on the observed meteorological data from l981 to 2010 in Hebei province, the temporal and spatial distributions of haze days were analyzed according to the observation and forecast standard of haze. The forming reason was discussed using haze days in Shijiazhuang as a case study. The results indicate that the haze days appear frequently in the east of Taihangshan mountain area. The center of the great frequency haze days expanses with the time, and the frequency is in a increasing trend. The haze days have three changing styles in the representative station, namely, increasing, decreasing and stability. There is a significantly change between stations. The haze days are mainly light haze and its visibility is more than five kilometers in Hebei province. There is a significantly seasonal change for the middle and serious haze days in the representative station. Most haze days appear in autumn and winter and account for 64% of the total. The haze formation is a result of combing effects from many factors. The regional distribution of haze days is related with the geographical environment and climatic factors such as inversion temperature, wind speed, relative humidity, and annual precipitation days. Furthermore, air pollutant emissions caused by the local economy development and the human society action could also lead to the haze.

Key words: Haze, Visibility, Forming reason