Standardized precipitation evapotranspiration index shows drought trends in China.
Standardized precipitation evapotranspiration index shows drought trends in China.
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DOI：
10.3724/sp.j.1011.2012.00643
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发表时间：
2012-01-01
期刊：
影响因子：
--
通讯作者：
Chen, Z. L.
中科院分区：
文献类型：
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作者：
Li WeiGuang, Li WeiGuang;Yi Xue, Yi Xue;Chen, Z. L.
标准降水蒸散指数(SPEI)是根据潜在蒸散量与降雨量之差计算的，它显示了与正常情况下的干湿偏差。这通常被用作干旱评估、水资源管理和其他水文学领域干旱演变趋势的指标。利用中国全市160个气象站1951-2009年的月平均地面气温和降水资料，利用SPAI软件分析了该地区的季节干旱趋势和极端干旱事件频数的空间分布特征。结果表明，中国全区呈现干燥趋势。最严重的干旱发生在中国的西部、北部和东北部。然而，在新疆北部的一些地区以及四川和云南的边境地区，天气很潮湿。四季均有干燥趋势，春季和秋季最为明显。在过去的15年里，夏季一直是干燥的，尽管在0.05水平上干燥的趋势不显著。此外，极端干旱的频率显著增加。在中国东北部和北部的许多站，气温有明显的上升趋势，降水量有中度下降的趋势。降水和气温的共同作用造成了该国的严重干旱。在四川盆地，降水明显减少，气温变化不大。四川盆地的干旱很大程度上归因于降水量的减少。近年来，中国多地极端干旱事件增多，降水事件频次减少。大范围的干旱趋势和极端干旱事件的显着增加可能阻碍了中国的经济发展。SPI监测到的干旱趋势与中国观测到的干旱趋势基本一致，表明SPI是监测干旱趋势的理想指标。
Standardized precipitation evapotranspiration index (SPEI), calculated from the difference between potential evapotranspiration and precipitation, showed dry and wet deviations from normal conditions. This is generally used as an indicator for drought evolution trends in drought assessments, water resources management and other fields of hydrology. Using monthly mean surface air temperature and precipitation collected from 160 meteorological stations across China for 1951-2009, spatial distributions of seasonal drought trends and frequencies of extreme drought events were analyzed via SPEI. The results showed drying trends across the whole of China. The most significant drought was in the west, north and northeast of China. It was, however, wet in some regions of northern Xinjiang and the border regions of Sichuan and Yunnan. Drying trends existed for all four seasons, and were more obvious in spring and autumn. Summer was always dry in the last 15 years, although with a drying trend insignificant at the 0.05 level. Furthermore, the frequency of extreme drought increased significantly. Significant trends in temperature increase along with moderate trends in precipitation decline were noted for many stations in the northeast and north of China. The combined effects of precipitation and temperature caused significant droughts in the country. In the Sichuan Basin, precipitation significantly decreased with no significant change in temperature. Drought in Sichuan Basin was largely attributed to decreasing precipitation. In recent years, extreme drought events increased with decreasing frequencies of precipitation events in many areas of China. Widespread drought trends and significant increases in extreme drought events probably hindered China's economic development. SPEI-detected drought trends were mostly consistent with observed droughts in China, indicating that SPEI was an ideal index for monitoring drying trends.