State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100039, China; Department of Geography, Ghent University, Ghent 9000, Belgium; Sino-Belgian Joint Laboratory of Geo-information, Urumqi, China; Sino-Belgian Joint Laboratory of Geo-information, Ghent, Belgium.
State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Sino-Belgian Joint Laboratory of Geo-information, Urumqi, China; Sino-Belgian Joint Laboratory of Geo-information, Ghent, Belgium.
Sci Total Environ. 2018 May 15;624:1523-1538. doi: 10.1016/j.scitotenv.2017.12.120. Epub 2017 Dec 28.
In drought-prone regions like Central Asia, drought monitoring studies are paramount to provide valuable information for drought risk mitigation. In this paper, the spatiotemporal drought characteristics in Central Asia are analyzed from 1966 to 2015 using the Climatic Research Unit (CRU) dataset. Drought events, as well as their frequency, duration, severity, intensity and preferred season, are studied by using the Run theory and the Standardized Precipitation Evapotranspiration Index (SPEI) at 3-month, 6-month, and 12-month timescales. The Principle Components Analysis (PCA) and the Varimax rotation method, the Sen's slope and the Modified Mann-Kendall method (MMK), as well as the wavelet analysis are adopted to identify the sub-regional drought patterns and to study the drought trend, periodicity and the possible links between drought variation and large-scale climate patterns, respectively. Results show that the drought characteristics in Central Asia vary considerably. The Hexi Corridor region and the southeastern part suffered from more short-term drought occurrences which mostly occurred in summer while the northeastern part experienced fewer droughts with longer duration and higher severity. Central Asia showed an overall wetting trend with a switch to drying trend since 2003. Regionally, the continuous wetting trend is found in north Kazakhstan while a consistent drying in the Aral Sea and Hexi Corridor region is observed in the last half-century. For 2003-2015, a significant drying pattern is detected in most Central Asia, except the northern Kazakhstan. A common significant 16-64-month periodical oscillation can be detected over the six sub-regions. The drought changes in Central Asia are highly associated with ENSO but less related to the Tibetan Plateau pressure. The North Atlantic Oscillation has an influence on drought change in most Central Asia but less for the Hexi Corridor and the drought variation in eastern Central Asia is affected by the strength of the Siberian High.
在中亚等干旱频发地区，干旱监测研究对于减轻干旱风险至关重要。本研究利用气候研究单位（CRU）数据集，分析了 1966 年至 2015 年中亚地区的时空干旱特征。采用 Run 理论和标准化降水蒸散指数（SPEI），研究了干旱事件及其频率、持续时间、严重程度、强度和偏好季节。采用主成分分析（PCA）和 Varimax 旋转方法、Sen 斜率和修正 Mann-Kendall 方法（MMK）以及小波分析，分别识别亚区域干旱模式，研究干旱趋势、周期性以及干旱变化与大尺度气候模式之间的可能联系。结果表明，中亚的干旱特征差异很大。河西走廊地区和东南部地区遭受了更多的短期干旱，主要发生在夏季，而东北部地区则较少发生干旱，但持续时间更长，严重程度更高。中亚整体呈变湿趋势，自 2003 年以来转为变干趋势。区域上，哈萨克斯坦北部呈持续变湿趋势，半个世纪以来，咸海和河西走廊地区持续变干。2003-2015 年，除哈萨克斯坦北部外，中亚大部分地区均出现显著干旱模式。六个亚区域均检测到一个共同的 16-64 个月周期振荡。中亚的干旱变化与厄尔尼诺-南方涛动密切相关，但与青藏高原气压关系不大。北大西洋涛动对中亚大部分地区的干旱变化有影响，但对河西走廊和中亚东部的干旱变化影响较小，西伯利亚高压的强度对其有影响。
