School of Environment, Northeast Normal University, Changchun 130024, China; Key Laboratory for Vegetation Ecology, Ministry of Education, Changchun 130024, China; College of Geography, Inner Mongolia Normal University, Hohhot 010022, China.
School of Environment, Northeast Normal University, Changchun 130024, China; College of Geography, Inner Mongolia Normal University, Hohhot 010022, China; Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot 010022, China.
Sci Total Environ. 2018 Feb 15;615:1557-1565. doi: 10.1016/j.scitotenv.2017.09.121. Epub 2017 Sep 18.
Knowledge about variations of drought can provide a scientific basis for water resource planning and drought mitigation. In this study, the variations and patterns of drought identified by the Standardized Precipitation Evapotranspiration Index (SPEI) were investigated on the Mongolian Plateau for the period 1980-2014, based on intensity analysis, linear regression, the Mann-Kendall test, wavelet analysis, and Hurst exponent. The results show that: 1) the annual SPEI decreased at a rate of -0.0133/yr over the past 35years, and a major abrupt change occurred in 1999; 2) drought on the Mongolian Plateau intensified from 1980 to 2014, and the drought in Mongolia has been more serious than in Inner Mongolia since the beginning of the 21st century; 3) the rate of drought/wet changes in 1980s-1990s and 1990s-2000s were faster than in 2000s-2010s. In 1980s-1990s, the different drought levels were transformed into various wet levels. In 1990s-2000s, the wet levels were transformed into drought, and in 2000s-2010s, the losses of drought levels were larger than the gains in wet levels; 4) the Hurst exponent is a reliable way to predict drought tendency, with a predictive accuracy as high as 91.7%; 5) the mean H value of the SPEI time series during 1980-2014 was 0.533, indicating that the future drought trend is generally consistent with the current state. In the future, the proportion of area with increasingly severe drought (72.2%) will be larger than that with increasingly wetter conditions (27.8%) on the Mongolian Plateau.
关于干旱变化的知识可以为水资源规划和干旱缓解提供科学依据。本研究基于强度分析、线性回归、Mann-Kendall 检验、小波分析和赫斯特指数，利用标准化降水蒸散指数（SPEI）探讨了 1980-2014 年期间蒙古高原干旱的变化和特征。结果表明：1）过去 35 年，SPEI 呈每年减少 0.0133/yr 的趋势，1999 年发生了一次重大突变；2）1980 年至 2014 年，蒙古高原的干旱加剧，21 世纪初以来，蒙古国的干旱比内蒙古自治区更为严重；3）1980-1990 年代和 1990-2000 年代的干湿变化率快于 2000-2010 年代。在 1980-1990 年代，不同的干旱程度转化为各种湿润程度。在 1990-2000 年代，湿润程度转化为干旱，在 2000-2010 年代，干旱程度的损失大于湿润程度的增益；4）赫斯特指数是预测干旱趋势的可靠方法，预测准确率高达 91.7%；5）1980-2014 年 SPEI 时间序列的平均 H 值为 0.533，表明未来干旱趋势与当前状态大致一致。未来，蒙古高原上干旱程度日益严重（72.2%）的面积比例将大于湿润程度日益增加（27.8%）的面积比例。
