干旱区生态环境知识资源中心(Arid): 青藏高原深层土壤热扩散率的时空分布特征

Arid

	青藏高原深层土壤热扩散率的时空分布特征
其他题名	Spatio-temporal Distribution of Thermal Diffusivity in Deep Soil in Qinghai-Tibetan Plateau
	周亚 1; 高晓清 2; 李振朝 2; 杨丽薇 2; 惠小英 2
来源期刊	土壤学报
ISSN	0564-3929
出版年	2018
卷号	55 期号:2 页码:351-359
中文摘要	青藏高原是地气相互作用相对活跃的地区,深入了解青藏高原土壤热扩散率的变化,才能正确计算地表能量平衡进而准确认识青藏高原对全球和区域气候变化的影响。根据青藏高原19802001年39个观测站点实测的0.8 m和3.2 m土壤温度资料,利用热传导对流法结合最小二乘法拟合求得各站点的土壤热扩散率,并分析了土壤热扩散率的时空变化规律。结果表明,19802001年期间青藏高原土壤热扩散率在20世纪90年代以前波动较大,20世纪90年代以后波动较小。青藏高原东部地区的深层土壤热扩散率从春季至夏季增大,夏季至秋季减小,秋季至冬季减小;夏季最大值出现在青、川、甘三省的交界处,土壤热扩散率的值为810~(-6)m~2 s~(-1),冬季最大值为5.110~(-7)m~2 s~(-1);而除东部以外的青藏高原其他地区的土壤热扩散率,春季至夏季减小,夏季至秋季增加,秋季至冬季减小,该区域土壤热扩散率的变化范围为1.210~(-7)m~2 s~(-1)~9.210~(-7) m~2 s~(-1)。土壤热扩散率的多年平均最大值出现在青海省和甘肃省西南部以及四川西部的青藏高原东部地区,土壤热扩散率的极值为6.4 10~(-6) m~2 s~(-1)。最小值出现在祁连山地区,土壤热扩散率为1.2 10~(-7) m~2 s~(-1),中部地区为相对高值区。
英文摘要	【Objective】The Qinghai-Tibet Plateau is an area relatively active in ground-air interaction. Only through understanding in depth variation of soil thermal diffusivity in the Qinghai-Tibet Plateau, can the surface energy balance on the Plateau be correctly calculated and the impact of the Plateau on global and regional climate change be understood in depth.【Method】Based on the data of soil temperatures at 0.8 m and 3.2 m deep in soil profiles accumulated in the 39 observation sites in the Qinghai-Tibet Plateau during the years from 1980 to 2001,thermal diffusivity of each observation site was worked out through fitting of the heat conduction convection method coupled with the least square method, and spatio-temporal variation of soil thermal diffusivity figured out.The heat conduction convection method encompasses heat conduction and thermal convection in calculating soil thermal conductivity. The amplitude and phase was obtained through fitting of the measured soil temperatures at the two soil depth with the least squares method, and substituted into the formula to yield soil thermal diffusivities. [ Result】Results show that from 1980 to 2001, soil thermal diffusivity of the Qinghai-Tibet Plateau appeared to be on a declining trend. It fluctuated quite sharply before the 1990s and less in the 1990s. As affected by climate factors, soil properties and soil moisture content, soil thermal diffusivity vary in spatial distribution. Soil thermal diffusivity in the deep soil in the eastern part of the Qinghai-Tibet Plateau increased from spring to summer and decreased from summer to autumn and from autumn to winter. It peaked in summer up to 8 * 10~(-6) m~2 s~(-1) in summer at the junction of Qinghai Province, Sichuan Province and Gansu Province and in winter up to 5.1 * 10~(-7) m~2 s~(-1).In the rest of the Plateau, soil thermal diffusivity decreased from spring to summer, increased from summer to autumn and decreased again from autumn to winter, varying in the range of 1.2 * 10~(-7) m~2 s~(-1) to 9.2 * 10~(-7) m~2 s~(-1).For years the maximum mean monthly value of soil thermal diffusivity wasobserved in the eastern part of the Qinghai-Tibet Plateau,including Qinghai,Southwest of Gansu and West Sichuan,being 6.4 * 10~(-6) m~2 s~(-1),whereas the minimum was in the region of Qilian Mountains,being 1.2 * 10~(-7) m~2 s~(-1),and the mean monthly soil thermal diffusivity was relatively highin the central part of the Plateau. As affected by geographical location, soil properties, soil moisture content and number of snow coverage days, the central and eastern parts of the Plateau, to the northeast part of Nagqu, are sorted as alpine frigid humid climate zone, where the soil thermal diffusivity is high due to high precipitation and high soil water content, andthe area of the Qilian Mountains is as alpine frigid semi-arid climate zone, where the soil thermal diffusivity is low varying in the range of 1 * 10~(-7) ~4.8 * 10~(-7) m~2 s~(-1) because it is a permafrost region low in soil water content. In most parts of the Qinghai-Tibet Plateau, soil thermal diffusivity varies in the magnitude order of10~(-7) m~2 s~(-1), and in the central and eastern parts abeingrelatively high-valued regions, it does in the magnitude order of 10~(-6) m~2 s~(-1).【Conclusion】All the findings in this study demonstrate that soil thermal diffusivity varies sharply temporally and spatially, as affected by a complicated variety of factors,which merit further studies.
中文关键词	青藏高原 ; 土壤热扩散率 ; 空间分布 ; 季节差异 ; 土壤温度 ; 热传导对流法
英文关键词	Qinghai-Tibet Plateau Soil thermal diffusivity Spatial distribution Seasonal differences Soil temperature Conduction-convection method
语种	中文
国家	中国
收录类别	CSCD
WOS类目	METEOROLOGY ATMOSPHERIC SCIENCES
WOS研究方向	Meteorology & Atmospheric Sciences
CSCD记录号	CSCD:6209912
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/238417
作者单位	1.中国科学院西北生态环境资源研究院;;中国科学院大学, 中国科学院寒旱区陆面过程与气候变化重点实验室;;, 兰州;;, ;;北京 730000;;100049; 2.中国科学院西北生态环境资源研究院, 中国科学院寒旱区陆面过程与气候变化重点实验室, 兰州, 甘肃 730000, 中国
推荐引用方式 GB/T 7714	周亚,高晓清,李振朝,等. 青藏高原深层土壤热扩散率的时空分布特征[J],2018,55(2):351-359.
APA	周亚,高晓清,李振朝,杨丽薇,&惠小英.(2018).青藏高原深层土壤热扩散率的时空分布特征.土壤学报,55(2),351-359.
MLA	周亚,et al."青藏高原深层土壤热扩散率的时空分布特征".土壤学报 55.2(2018):351-359.