摘要
为探明内蒙古地区历年干旱演变特征及其趋势,利用内蒙古地区43个测站51 a(1960—2010年)的逐日降水资料计算各站的标准化降水指数,在此基础上分析了全年及各季节的干旱发生频率、干旱站次比及干旱强度的年际变化,并通过Hurst指数对内蒙古地区的干旱化趋势进行预测.结果表明:年尺度上干旱频率在10.46%~33.66%,其中呼伦贝尔的干旱频率最高,位于阿拉善盟的额济纳干旱频率最低,干旱发生不明显,各月、季与年的干旱频率基本一致.年尺度干旱站次比最高为45.74%,最低为15.50%,51 a中分别有11,26和14 a发生区域性、部分区域性和局域性干旱.干旱强度以轻度干旱和中度干旱为主,其中有15 a出现中度干旱,干旱强度最大值是1.14.内蒙古地区春季、夏季和秋季干旱发生频率相对较高,平均为30%左右,冬季干旱频率平均为25.41%,并且冬旱各测站干旱频率分布不均,额济纳等4个测站冬旱的干旱频率为0.干旱站次比夏季和秋季分别以0.177/10 a和0.006/10 a的趋势增加,春季和冬季以0.033/10 a和0.156/10 a的趋势减少.季尺度干旱强度的变化趋势与干旱站次比变化趋势基本一致.内蒙古地区的SPI序列呈明显的Hurst现象,指数值0.568 7大于0.500 0,表明该区干旱化程度还有可能持续一段时间,中旱及以上发生的频率有减少趋势.
To explore the evolution characteristics and trends of drought over the years in Inner Mongolia, standardized precipitation index （SPI） in the recent 51 years （1960-2010） was calculated with the daily precipitation data from 43 weather stations in Inner Mongolia, the annual and seasonal drought frequency, its station frequency ratio and drought intensity were analyzed, and the trend of drought was predicted by using the Hurst index. The results show that the annual drought frequency was in the range of 10.46% -33.66% , the highest frequency （33.66%） occurred in Hulun Buir, and the lowest one （ 10.46% ） was in Ejina of Alxa League, additionally, the monthly and seasonal drought frequencies were consistent with the yearly drought frequency. The highest station frequency ratio was 45.74% , and the lowest one was 15.50% , particularly, the regional, partly regional and lo- cal droughts occurred in 11,26 and 14 years, respectively. The drought intensity was mainly mild and moderate, and the maximum intensity was 1.14 in 15 years. Drought frequency was relatively high in spring, summer and autumn with a mean of about 30%, while in winter the frequency was 25.41%, moreover the drought frequency was distributed unevenly among the weather stations, for example, the drought frequency was 0 at 4 stations including Ejina. Station frequency ratio increased at the rates of 0. 177/10 a and 0. 006/10 a in summer and autumn, decreased at the rates of 0.033/10 a and 0. 156/ 10 a in spring and winter, respectively. The variation trend of drought intensity was basically the same as the station frequency ratio in seasonal scale. The SPI sequence exhibited a remarked Hurst pheno- menon in Inner Mongolia, and the index （0. 568 7 ） was more than 0.5 000, indicating that the drought degree could sustain for some time, while the frequency of the occurrence of moderate drought and above showed a decreasing trend.
出处
《排灌机械工程学报》
EI
CSCD
北大核心
2017年第5期430-439,共10页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51109102
51469010)
云南省应用基础研究项目(2014FB130)
云南省教育厅科学研究基金重点项目(2011Z035)
关键词
内蒙古
干旱
降水
标准化降水指数
趋势预测
时空分布
Inner Mongolia
drought
precipitation
standardized precipitation index
trend prediction
spatial and temporal distribution
