Observed changes of drought/wetness episodes in the Pearl River basin, China, using the standardized precipitation index and aridity index
Observed changes of drought/wetness episodes in the Pearl River basin, China, using the standardized precipitation index and aridity index
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DOI：
10.1007/s00704-008-0095-4
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发表时间：
2009-01
影响因子：
3.4
通讯作者：
Qiang Zhang;Chong-yu Xu;Zeng-xin Zhang
中科院分区：
文献类型：
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作者：
Qiang Zhang;Chong-yu Xu;Zeng-xin Zhang
利用珠江流域42个雨站1960-2005年逐月降水资料，采用标准化降水指数(SPI)和干旱指数(I)对珠江流域雨季(4-9月)和冬季(12-2月)的异常干湿状况进行了分类。用Mann-Kendall技术检测SPI所决定的干湿月数的变化趋势。此外，我们还通过分析NCAR/NCEP再分析数据集，研究了干湿变化背后的可能原因。结果表明：(1)珠江流域雨季偏干，冬季偏湿。(2)珠江流域在雨季以干旱为主，干旱指数(I)的变化进一步证实了这一点；(3)珠江流域的水汽通量、雨季和冬季的水分变化表明，水分变化对整个珠江流域的干湿状况有不同的影响。水分含量的增加会导致冬季潮湿月份的增加。然而，雨季水分变化与雨季雨月数之间没有固定的关系，这表明有多个因素可以影响研究区的干湿状况。本文的研究成果对气候变化条件下的流域水资源管理具有一定的参考价值。
Monthly precipitation data of 42 rain stations over the Pearl River basin for 1960–2005 were analyzed to classify anomalously wet and dry conditions by using the standardized precipitation index (SPI) and aridity index (I) for the rainy season (April–September) and winter (December–February). Trends of the number of wet and dry months decided by SPI were detected with Mann-Kendall technique. Furthermore, we also investigated possible causes behind wet and dry variations by analyzing NCAR/NCEP reanalysis dataset. The results indicate that: (1) the Pearl River basin tends to be dryer in the rainy season and comes to be wetter in winter. However, different wetting and drying properties can be identified across the basin: west parts of the basin tend to be dryer; and southeast parts tend to be wetter; (2) the Pearl River basin is dominated by dry tendency in the rainy season and is further substantiated by aridity index (I) variations; and (3) water vapor flux, moisture content changes in the rainy season and winter indicate different influences of moisture changes on wet and dry conditions across the Pearl River basin. Increasing moisture content gives rise to an increasing number of wet months in winter. However, no fixed relationships can be observed between moisture content changes and number of wet months in the rainy season, indicating that more than one factor can influence the dry or wet conditions of the study region. The results of this paper will be helpful for basin-scale water resource management under the changing climate.