Soil moisture drought detection and multi-temporal variability across China  

作　　者：LI MingXing MA ZhuGuo 

机构地区：[1]Key Laboratory of Regional Climate-Environment for East Asia, Institute of Atmospheric Physics,Chinese Academy of Sciences

出　　处：《Science China Earth Sciences》2015年第10期1798-1813,共16页中国科学（地球科学英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2012CB956202);the National Key Technology R&D Program of China(Grant Nos.2013BAC10B02,2012BAC22B04);the National Natural Science Foundation of China(Grant No.41105048)

摘　　要：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 China's Mainland.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,with77.3%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.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 China's Mainland. 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.

关 键 词：soil moisture droughts soil moisture CLM3.5 land surface process modeling 

分 类 号：S152.7[农业科学—土壤学]