干旱区生态环境知识资源中心(Arid): 半干旱区榆中地表粗糙度年变化及影响机理

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	半干旱区榆中地表粗糙度年变化及影响机理
其他题名	The Annual Variation and Its Influencing Mechanism of Surface Roughness Length of Yuzhong in Semi-arid Areas
	姚彤 1; 张强2 ; 尹晗 3
来源期刊	应用气象学报
ISSN	1001-7313
出版年	2014
卷号	25 期号:4 页码:454-462
中文摘要	利用2006年6月ー2010年12月兰州大学半干旱气候与环境观测站(SACOL)观测资料,分析了黄土高原自然植被下垫面榆中地表粗糙度时间变化特征,考虑到地形、植被物理特征以及降水和热力条件的影响,分析了东南风向和西北风向粗糙度年变化规律及其影响机理,并分别给出这两个风向归一化粗糙度与时间的拟合关系式。研究发现:对于非均一下垫面,由于地形起伏和下垫面植被差别造成的不同风向粗糙度差异显著。选取东南风向和西北风向,这两个风向的地表粗糙度无论是量级还是年变化特征都有很大差别,且由于地形和植被的差别,东南风向粗糙度年变化趋势与稳定度年变化趋势一致,粗糙度与稳定度存在一定相关关系,而西北风向粗糙度年变化趋势与降水量年变化趋势一致,粗糙度与降水量相关性较好。
英文摘要	Based on data observed at the Semi-arid Climate and Environment Observatory of Lanzhou University (SACOL) from June 2006 to December 2010,temporal characteristics of aerodynamic roughness length over the natural vegetation surface of Yuzhong are analyzed. Annual change characteristics of roughness length and influencing mechanisms in the southeast and northwest are analyzed, taking the impact of terrain, vegetation, precipitation and thermal conditions into account, and the fitting relationships between normalized roughness and time are given. It shows that for heterogeneous underlying surface,the difference of aerodynamic roughness length in different wind directions caused by undulating terrain and vegetation difference is very significant. According to the prevailing wind direction, two wind directions which are southeast and northwest are selected. Both magnitude and changing trends of roughness length of two selected wind directions are remarkable different. The averaged roughness length in southeast is 0. 015 m, whose magnitude is equal to the roughness length over sparsely vegetated underlying surface like deteriorated grassland, while the averaged roughness length in northwest is 0. 123 m, whose magnitude is equal to the roughness length over farmland underlying surface. To eliminate effects of the inter-annual variation of roughness length, the normalized roughness length is injected into the discussion. The time-distributing characteristics in two wind directions vary considerably, which can be considered showing opposite trends. The annual changing trend of roughness length in southeast decreases first and then increases, while it increases first and then decreases in northwest. And due to differences in terrain and vegetation, influencing mechanisms of the time variation of roughness length in the two wind directions are different. The annual variation trend of normalized roughness is consistent with the annual variation of atmospheric stability and the roughness length has a certain relationship with atmospheric stability in southeast due to the stunted sparse vegetation. While the annual variation trend of roughness length is consistent with the annual variation of precipitation and the roughness length has a good relationship with precipitation in northwest due to the impact of vegetation, and the vegetation is mainly effected by the precipitation. The time parametric relationship between normalized roughness and time in two directions can be described by a set of sinusoidal functions, and the related coefficient can reach 0. 49 and 0. 82,respectively.
中文关键词	半干旱区 ; 粗糙度 ; 年变化规律 ; 参数化关系
英文关键词	semi-arid area aerodynamic roughness length annual variation parametric relationship
语种	中文
国家	中国
收录类别	CSCD
WOS类目	MULTIDISCIPLINARY SCIENCES
WOS研究方向	Science & Technology - Other Topics
CSCD记录号	CSCD:5195090
来源机构	兰州大学 ; 中国气象局兰州干旱气象研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/231975
作者单位	1.兰州大学大气科学学院, 甘肃省干旱气候变化与减灾重点实验室;;中国气象局干旱气候变化与减灾重点开放实验室, 兰州, 甘肃 730000, 中国; 2.中国气象局兰州干旱气象研究所, 甘肃省干旱气候变化与减灾重点实验室;;中国气象局干旱气候变化与减灾重点开放实验室, 兰州, 甘肃 730020, 中国; 3.中国人民解放军93801部队, 武功, 712200
推荐引用方式 GB/T 7714	姚彤,张强,尹晗. 半干旱区榆中地表粗糙度年变化及影响机理[J]. 兰州大学, 中国气象局兰州干旱气象研究所,2014,25(4):454-462.
APA	姚彤,张强,&尹晗.(2014).半干旱区榆中地表粗糙度年变化及影响机理.应用气象学报,25(4),454-462.
MLA	姚彤,et al."半干旱区榆中地表粗糙度年变化及影响机理".应用气象学报 25.4(2014):454-462.