近50年贵德县旱涝灾害变化特征分析

利用青海省贵德气象站1961—2010年逐日平均气温、逐月降水资料以及逐日最高、最低气温资料,分析近50a气温、降水以及最高最低气温的变化趋势,并对其突变年份进行了检测。用降水量来确定贵德县旱涝等级,进而确定出贵德县气温突变前后旱涝等级出现的年份及所占的比例。结果表明:贵德地区偏旱、正常和偏涝的状态不断增加,增加的比例为旱>正常>偏涝。运用马尔柯夫模型对未来5a的旱涝状态进行了预测,2011—2015年处于"偏涝"的概率较大。

Changes of Drought and Waterlog Disasters over the Last 50 Years in Guide County,Qinghai Province

The data for this study were collected at the weather station of Guide,Qinghai Province,including average daily temperatures of every day,monthly precipitation,and the daily highest and lowest temperatures from 1961 to 2010.According to these data,trends of atmospheric temperatures,precipitation and the daily highest and lowest temperatures over the last 50 years were analyzed,and the years of abrupt changes were checked.We judged drought or waterlog degrees from concurrent precipitation,so as to compare the years of drought or waterlog disasters and their ratios before and after the abrupt changes.The results showed that drought and waterlog disasters became more frequent over the last 50 years.The results of Markovian analysis indicated that waterlog disasters would be in greater probabilities in 5 years from 2011 to 2015.