干旱区生态环境知识资源中心(Arid): 青海共和盆地不同发育阶段风蚀坑表面气流场与形态反馈研究

Arid

	青海共和盆地不同发育阶段风蚀坑表面气流场与形态反馈研究
其他题名	Form-flow Feedback within Blowouts at Different Developing Stages in the Gonghe Basin,Qinghai Province
	车雪华; 罗万银; 邵梅; 王中原
来源期刊	地球科学进展
ISSN	1001-8166
出版年	2021
卷号	36 期号:1 页码:95-109
中文摘要	风蚀坑是沙质草原沙漠化的主要地貌响应和驱动,但目前我们对其形成演化的动力机制知之甚少。利用二维超声风速仪和积沙仪观测了共和盆地不同发育阶段风蚀坑表面气流和风沙流特征,研究其形态-动力反馈过程。结果表明:①风蚀斑与碗状坑内气流沿主风向先减速后加速,槽形坑内气流则先辐散减速-中部气流加速-积沙体迎风坡风速降低-背风坡风速有所恢复;且发育初期风蚀坑内风速与风速变异系数和风向稳定系数均呈负相关,而发育中期坑内风速与前者呈正相关,与后者呈负相关。②受坑体内的涡流影响,槽形坑内风速廓线不符合对数分布规律。③槽形坑内不同部位的输沙率随高度均呈指数式递减,但受气流-形态间的反馈作用,各部位输沙通量差异明显,坑底最低、积沙体迎风坡前端最大。风蚀坑内气流场与形态间存在反馈关系,坑体越大反馈效果越明显。
英文摘要	Blowouts are the primary geomorphologic manifestation and driving force of sandy grassland desertification in the Gonghe Basin.However,their feedback mechanism between the flow dynamics and geomorphology is unclear.Two-dimensional ultrasonic anemometers and gradient sand traps were used in this study to measure the characteristics of wind flows and sediment transport at different blowouts of different developing stages in the Gonghe Basin.The feedback between the morphology-dynamic processes of the blowouts was discussed.Results show as follows.①After entering the sand patch and small bowl blowout along the prevailing wind direction,air flow expanded and decelerated,and then accelerated until going outside the blowout;when entering a trough blowout of a small or medium size,it expanded and decelerated at the headwall,accelerated at the bottom of blowout,decelerated at the windward slope of the depositional lobe,and then recovered somewhat at the leeside slope of the depositional lobe.Besides,the wind speed was negatively correlated with steadiness of flow and directional steadiness in the early stage of blowout,but was positively correlated with the steadiness of flow and negatively correlated with the directional steadiness in the middle stage of blowout.②Due to the rotating vortices in the blowout,the wind speed profiles in the trough blowout displayed a nonlogarithmic behavior.③The measured sand flux density at different stations decreased exponentially with height.However,due to the feedback effect between flow dynamics and morphology,the sediment transport fluxes at different positions were obviously different,with the lowest at the bottom of the blowout and the largest in front of the windward slope of the deposition lobe.In conclusion,there is a form-flow feedback in the blowout,and the bigger the blowout is,the more obvious the feedback effect is.
中文关键词	风蚀坑 ; 沙漠化 ; 表面气流 ; 形态反馈
英文关键词	Blowout Desertification Surface air flow Form-flow feedback
类型	Article
语种	中文
收录类别	CSCD
WOS类目	Geology
CSCD记录号	CSCD:6918907
来源机构	中国科学院西北生态环境资源研究院 ; 北京师范大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/354215
作者单位	车雪华, 中国科学院西北生态环境资源研究院;;中国科学院大学, 中国科学院沙漠与沙漠化重点实验室;;, 兰州;;, 甘肃;;北京 730000;;100049, 中国. 邵梅, 中国科学院西北生态环境资源研究院;;中国科学院大学, 中国科学院沙漠与沙漠化重点实验室;;, 兰州;;, 甘肃;;北京 730000;;100049, 中国. 罗万银, 中国科学院西北生态环境资源研究院, 中国科学院沙漠与沙漠化重点实验室, 兰州, 甘肃 730000, 中国. 王中原, 北京师范大学地理科学学部, 北京 100875, 中国.
推荐引用方式 GB/T 7714	车雪华,罗万银,邵梅,等. 青海共和盆地不同发育阶段风蚀坑表面气流场与形态反馈研究[J]. 中国科学院西北生态环境资源研究院, 北京师范大学,2021,36(1):95-109.
APA	车雪华,罗万银,邵梅,&王中原.(2021).青海共和盆地不同发育阶段风蚀坑表面气流场与形态反馈研究.地球科学进展,36(1),95-109.
MLA	车雪华,et al."青海共和盆地不同发育阶段风蚀坑表面气流场与形态反馈研究".地球科学进展 36.1(2021):95-109.