Han J.,Shijiazhuang Meteorological Bureau of Hebei Province |
Qian W.,Shijiazhuang Meteorological Bureau of Hebei Province |
Li L.,Shijiazhuang Meteorological Bureau of Hebei Province |
Diao S.,Shijiazhuang Meteorological Bureau of Hebei Province
Journal of Natural Disasters | Year: 2014
Based on daily maximum and minimum temperature data of 16 county stations and 1 city district station of Shijiazhuang City, the spatiotemporal variation characteristics of extreme temperature indices and urbanization effect were analyzed by use of linear trend and Mann-Kendall mutation test. The results show that, extreme high-temperature event centers mainly occur in the station of Shijiazhuang city district and the urban south-western area, while extreme low-temperature event centers in the urban north-eastern area. The extreme low-temperature event presents a decrease trend and the extreme high-temperature event presents an increase trend in most areas. In ten years scale, the cold nights and cold days decrease, while the warm nights and warm days increase significantly. The extreme temperature indices had an abrupt change around 1990 except the cold days. Due to the urbanization effect, the cold nights and the cold days significantly decrease, and the warm nights and warm days significantly increase. The urbanization effects on cold days and warm days are mainly in spring, on warm nights is mainly in summer, and on cold nights is mainly in winter. The urbanization effects on day and night extreme temperature indices have obvious differences, which may be related to the asymmetry of urban heat island effect.