云南省冰冻灾害气候区划

Climate Zoning of Frozen Disasters in Yunnan Province

通过对1951-2007年云南124个测站的冰冻样本及其对应的气温、风速、相对湿度等数据进行了统计分析,根据冰冻样本概括率和冰冻天气概括率建立了冰冻天气判别式。利用Cressman客观分析方法,对1958-2007年11月～次年4月逐日地面气温、相对湿度和风速进行了1km×1km细网格插值,在插值中考虑了气象要素随地形高度的变化并以扫描半径范围为地形订正单元。在这些基础上对云南省冰冻灾害进行了精细化气候区划,结果表明:(1)云南冰冻天气最严重的是滇东北地区,其次是滇西北地区,滇中和滇东南地区较轻,滇西南除高海拔地区外,几乎没有冰冻天气;(2)自1958年以来云南省冰冻天气总的趋势在减少,特别是21世纪以来的7年,仅2005年偏多,其余6年均偏少;(3)云南省冰冻灾害最严重的地区是滇东北的镇雄、威信、昭通、鲁甸等地和永善县五莲峰山区;其次是滇东曲靖市大部分地区、滇东南泸西和邱北的高海拔地区、滇西北德钦、维西、贡山及其所在的云岭地区;滇东和滇西北其他地区为轻度灾害区;其余发生过冰冻天气区域均为轻微灾害区。

Using the freezing samples and corresponding temperature,wind and relative humidity data of all stations in Yunnan Province from 1951 to 2007,the discriminant of freezing weather was founded by analyzing the generalizing ratios of freezing samples and freezing weather.Applying Cressman objective analysis method,the day-to-day temperature,wind and relative humidity data were interpolated into 1 km 1 km fine-grid from November 1958 to April 2007.In interpolation,meteorological factors changing with altitude was considered and terrain correcting unit was defined by the scanning radius area.On the basis of above works,the refined climate zoning of frozen disaster in Yunnan Province was obtained.The results indicated that：（1）The northeast of Yunnan Province is the most severe area of freezing weather,the northwest is the second severe area,the middle and southeast is lesser area.With the exclusion of higher latitude area,there is not almost freezing weather in southwest of Yunnan Province.（2）The total trend of freezing weather has been decreasing since 1958,especially in seven years of 21st century.Except for the total was above normal in 2005,the total was below normal in other six years.（3）The most severe districts of frozen disaster in Yunnan Province include Zhenxiong,Weixin,Zhaotong,Ludian and Wulianfeng mountainous area of Yongshan of the northeast of Yunnan Province.The second severe districts include the majority of Qujing of the east of Yunnan Province,the higher latitude area of Luxi and Qiubai of the southeast of Yunnan Province and Deqin,Weixi,Gongshan and the mountain area of them of the northwest of Yunnan Province.The other districts of the east and northwest of Yunnan Province are light frozen disaster area.The other districts where had taken place freezing weather are lighter frozen disaster area.