Soil moisture drought detection and multi-temporal variability across China
Soil moisture drought detection and multi-temporal variability across China
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DOI：
10.1007/s11430-015-5076-8
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发表时间：
2015-04
期刊：
影响因子：
--
通讯作者：
Mingxing Li;Zhuguo Ma
中科院分区：
文献类型：
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作者：
Mingxing Li;Zhuguo Ma
土壤水分干旱会引发土壤-植被-大气系统中物质和能量循环的异常变化，对当地的生态系统、天气和气候产生重要影响。干旱的探测和了解有助于减灾，以及在了解陆地-大气相互作用的基础上进行天气和气候预测。在此基础上，利用中国观测气候驱动的陆面模式CLM3.5模拟土壤水分，并在土壤水分参数化方案中引入土壤孔隙度参数，修正土壤水分模拟中的湿偏。然后，我们定义了土壤水分干旱来量化干旱的时空变异性。在1951年至2008年期间，40%的月份(总计12×58)遭受干旱，平均面积占大陆中国陆地总面积的54.6%。干旱地区年月旱情明显减少，半干旱半湿润地区明显增加，湿润地区有所减少，但差异不显著。大陆整体旱情呈上升趋势，77.3%的面积比例由降转升。月干旱以冬季最强，夏季最弱，分别影响内地总面积的54.3%及8.4%。持续3个月以上的干旱主要发生在半干旱半湿润地区，概率为51.7%，平均为77.6%；持续6个月和12个月以上的干旱主要发生在干旱半干旱地区。
Soil moisture droughts can trigger abnormal changes of material and energy cycles in the soil-vegetation-atmosphere system, leading to important effects on local ecosystem, weather, and climate. Drought detection and understanding benefit disaster alleviation, as well as weather and climate predictions based on the understanding the land-atmosphere interactions. We thus simulated soil moisture using land surface model CLM3.5 driven with observed climate in China, and corrected wet bias in soil moisture simulations via introducing soil porosity parameter into soil water parameterization scheme. Then we defined soil moisture drought to quantify spatiotemporal variability of droughts. Over the period from 1951 to 2008, 40% of months (to the sum of 12×58) underwent droughts, with the average area of 54.6% of total land area of Mainland China. The annual monthly drought numbers presented a significant decrease in arid regions, but a significant increase in semi-arid and semi-humid regions, a decrease in humid regions but not significant. The Mainland as a whole experienced an increasing drought trend, with 77.3% of areal ratio of decrease to increase. The monthly droughts in winter were the strongest but the weakest in summer, impacting 54.3% and 8.4% total area of the Mainland, respectively. The drought lasting three months or more occurred mainly in the semi-arid and semi-humid regions, with probability >51.7%, even >77.6%, whereas those lasting 6 and 12 months or more impacted mainly across arid and semi-arid regions.