摘要
Abstract
[ Objective ] The research aimed to study the climatic characteristics of hail in the southern mountain area of Ningxia in recent 50 years. [ Method] Based on the hail observation data of 5 surface meteorological stations (Guyuan, Xiji, Jingyuan, Longde, Liupanshan) in the south of Ningxia during 1960 -2009, the spatial distribution rule of hail, the interarnual, monthly climatic characteristics and the variation trends of hail in the south of Ningxia were analyzed by using the statistical method. Moreover, the hail disaster prevention and reduction measures in Guyuan were put forward. [ Result] The hail in the south mountain area of Ningxia in recent 50 years had the obvious annual, seasonal, monthly and daily variation characteristics. The hail might occur from March to October and mainly concentrated during May-August which occupied 72.0％ in the whole year. The occurrence probability of hail in June was the biggest and occupied 21.7％ in the whole year. It was the typical multi-hail zone in summer. The interannual variation of hail occurrence in Guyuan was big and had three-year periodic characteristic. The secondary-order time trend of hail in Guyuan was the inverted parabola type, and the hail occurrence times during the 1960s - 1980s presented the increase trend. It was the hail multi-occurrence period in the 1970s and 1980s. After the 1990s, the hail presented the decrease trend. In recent 20 years, the hail significantly decreased. The hail in Guyuan mainly concentrated during 12:00 -21:00, and the hail occurrence times occupied 85％ of total times. The hail distribution in Guyuan area had the obvious regional characteristic. The hail in the mountain area, hilly area was more and in the stream valley, north Pingchuan area was less. The hail cloud mainly derived from the mountain areas,such as Liupanshan, Nanhua Mountain, Yueliang Mountain, Xifeng Mountain and Yunwu Mountain, etc. The move direction of hail cloud was mainly form northwest to southeast or from north to south. A part of hail cloud formed and disappeared in the original place. According to the regional distribution of hail, the hail risk in Guyuan City was divided into the high occurrence area, the moderate occurrence zone and the low occurrence zone by combining with the hail disaster data. [ Conclusion] The research provided the scientific basis for the forecast, early-warning of hail weather and the artificial hail suppression.关键词
冰雹/气候特征/变化趋势/宁夏南部山区Key words
Hail/ Climatic characteristics/ Variation trend/ South mountain area of Ningxia分类
天文与地球科学
