适用于我国华南广西区域冬季的冷湿指数计算方法研究

根据我国华南冬季气温、降水的气候特点,使用广西国家级地面气象站的逐日平均气温和降水量数据,进行了我国南方湿冷程度表征指标的计算方法分析研究,通过细分不同量级的降水量对冬季低温冷害程度的影响,提出一种适用于华南广西区域冬季的冷湿指数计算方法,将这种新的冬季冷湿指数计算方法与以往的计算方法进行对比分析,结果表明,新指数在很大程度上修正原冷湿指数受降水量干扰太大的缺陷,是一种更为合理的适用于华南广西区域的冬季低温冷湿指数计算新方法。利用这种新方法计算的冷湿指数,以区域性低温雨雪冰冻事件为基础,同时兼顾低温雨雪冰冻事件的时间持续性,识别出一般区域性低温雨雪冰冻事件89例,严重区域性低温雨雪冰冻事件12例。识别结果与实际灾情记录比较符合。

Calculation Method of Cold-wet Index for the Winter in Guangxi Region of South China

According to the winter climatic characteristics of air temperature and precipitation in South China,we study the calculation method of wet and cold degree index in southern China by using daily mean temperature and rainfall data from Guangxi National ground weather Station.By subdividing the influence of precipitation of different magnitudes on the degree of cold damage in winter,we propose a cold-wet index calculation method suitable for winter in the Guangxi region of South China.Comparing the new winter cold-wet index calculation method with the previous calculation method,the results show that the new index can more accurately characterize the strength of low temperature chilling damage including dry-cold and cold-wet conditions.To a large extent,the new index corrects the defect that the original cold-wet index is too much interfered by the precipitation,and is a more reasonable new method for calculating the low temperature cold-wet index in winter in the Guangxi region of South China.Using the new cold-wet index based on the regional low-temperature and freezing rain event with the consideration of time-sustainable regional low-temperature rain and freezing rain,89 cases of general regional low temperature and freezing rain events and 12 cases of severe regional low temperature and freezing rain events were identified.The resulting recognition is in well accord with the observed disaster record.