为研究气候因子变化下的锡林河流域干旱风险,并为当地水资源与生态管理提供有效依据。通过计算锡林浩特、东乌珠穆沁旗等11个气象站点1982—2018年不同时间尺度(1,3,6,12个月)的标准化降水蒸散指数(SPEI),分析了锡林河流域年、季、月尺度上的干旱发生的频率和干旱强度,揭示了锡林河流域多年来的干旱时空演变特征。结果 表明:近37 a来锡林河流域SPEI整体呈现增长趋势,特、重旱的发生频率在逐年减小,轻、中旱的发生频率有波动起伏的不确定性,且存在发生季节性集中干旱的可能。从空间分析来看,锡林河流域在年、季、月尺度上均有干旱发生,在季节变化方面,干旱出现既有冬季的大范围干旱,也有春季的局部干旱,总体分布特征是西多北少; 干旱呈现出夏季最为严重,秋季次之的特点,总体分布从西北到东南表现为弱—严重—弱的特点。
To study the drought risk of the Xilin River Basin under the change of climatic factors, and provide an effective basis for local water resources and ecological management, by calculating the standardized precipitation evapotranspiration index(SPEI)of 11 meteorological stations in Xilinhot and Dongwuzhumuqi from different time scales(1, 3, 6 and 12 months)from 1982 to 2018, the frequency of drought and the intensity of drought on the annual, seasonal and monthly scales were analyzed to reveal the characteristics of drought and space-time evolution over the years in the Xilin River Basin. The results showed that the SPEI of the Xilin River Basin presented the growing trend in the past 37 years, the frequency of special and severe droughts had been decreasing year by year, the frequency of light and moderate droughts had the fluctuating uncertainty, and the seasonal concentrated drought occurred; from the perspective of spatial analysis, the droughts in Xilin River Basin occurred on the annual, seasonal and monthly scales, in terms of seasonal changes, large-scale droughts occurred in winter and local droughts occurred in spring, the overall distribution of drought was characterized as that the frequency of drought was low in the north is and high in the west; the drought was the most severe in summer, and followed by the autumn, the overall distribution was weak-severe-weak pattern from northwest to southeast.
