20世纪陇南洪涝灾害特征分析

历史上发生的自然灾害可以作为今后防灾减灾的重要参考资料。通过整理统计历史文献资料,对陇南20世纪洪涝灾害的时空分布特征、区域差异性进行分析、灾害序列趋势持续性计算。结果表明:20世纪陇南共发生洪涝灾害33次,平均3.3年1次;中度灾害最多,为11次,特大灾害共发生3次;灾害多发生在1949年到1990年,月份主要集中在6、7月,连年洪涝灾害也有发生;本区内的西和为高发区,礼县、两当、武都次之;徽县、成县最少。R/S分析法计算结果表明陇南市洪涝灾害时间序列具有长期相关的特征,未来有增加的趋势。

Analysis on the Flood Disaster Characteristics in the Longnan City in the 20 th Century

Natural disasters in history may be the important reference for future disaster prevention and mitigation.Based on the statistic of historical documents and materials,it was analyzed the spatial and temporal distribution of the flood disasters characteristics and regional differences in Longnan City in the 20 th century. Meanwhile,the disaster sequence trend in sustainability was also calculated. The results showed that,there were 33 times flood disasters in Longnan City in the 20 th century,once per 3. 3 years in average. Of which,there were 11 times moderate hazards and3 times of catastrophic flood disasters. Most of the hazards happened from 1949 to 1990,concentrated in June and July each year. In addition,consequent floods also occurred. Xihe County was the highest risk area for floods and the Li County,Liangdang County and Wudu County took the second place. Hui County and Cheng County were the lowest risk areas for flood disasters. In accordance with the R / S analysis method,it showed that the time series of flood of Longnan City has the features of long- term relativity with the trend of increase in the future.