干旱区生态环境知识资源中心(Arid): 乌兰布和沙区不同下垫面的土壤风蚀特征

Arid

	乌兰布和沙区不同下垫面的土壤风蚀特征
其他题名	Characteristics of Soil Wind Erosion under Different Underlying Surface Conditions in Ulanbuh Desert
	刘芳; 郝玉光; 辛智鸣; 徐军; 黄雅茹; 赵英铭; 孙非
来源期刊	林业科学
ISSN	1001-7488
出版年	2017
卷号	53 期号:3 页码:128-137
中文摘要	【目的】研究荒漠生态系统典型植被群落对近地层风沙活动的影响,揭示荒漠生态系统中不同下垫面条件的土壤风蚀特征。【方法】在乌兰布和沙区东北缘荒漠-绿洲过渡带内,选取油蒿半固定沙丘(盖度约20%) 、白刺半固定沙丘(盖度约30%) 、油蒿固定沙丘(盖度约40%) 、白刺固定沙丘(盖度约40%) 、流动沙丘(CK) 5种典型下垫面,运用风蚀钎和风沙流采集系统,实时监测5种下垫面的风蚀动态,定量分析不同下垫面条件下的土壤风蚀量、风蚀物的垂向分布及粒度组成的差异性。【结果】乌兰布和沙区不同下垫面同期土壤风蚀深度为:流动沙丘>油蒿半固定沙丘>白刺半固定沙丘>油蒿固定沙丘>白刺固定沙丘,当风速达到4.1 m·s~(-1)时,流动沙丘即可观察到沙粒蠕动,当风速达5.1 m·s~(-1)时积沙仪可收集到风蚀物。油蒿半固定沙丘、白刺半固定沙丘、油蒿固定沙丘、白刺固定沙丘的风速分别达到6.3,6.5,6.8,7.9 m·s~(-1)时方可发生风蚀; 5种下垫面0 ~ 100 cm垂直断面上,67.6% ~ 90.0%的风蚀输沙均分布于30 cm高度范围之内,挟沙气流中输沙率随高度增加呈幂函数规律递减,随风速增大呈幂函数规律递增,各高度层风蚀物粒度组成呈单峰态分布,峰值处在250 ~ 100 mum之间,0 ~ 20 cm高度层峰值与其余各层的峰值范围差异明显且偏向粒径趋大的方向;自下而上,极细沙的粒度构成比例呈递增趋势,中沙的粒度构成比例呈递减趋势。【结论】随着植被盖度的增加,土壤风蚀程度显著减轻,流动沙丘、半固定沙丘、固定沙丘年风蚀深度依次降低。盖度为40%的油蒿、白刺群落,其地表风蚀深度仅为流动沙丘同期风蚀深度的1.73% ~ 1.52%,0 ~ 100 cm高度范围内的输沙率仅为流动沙丘输沙率的6.6% ~ 5.1%。在荒漠生态系统中,植物群落主要通过覆盖地表、提高下垫面的粗糙度和拦截沙粒的运动来缓解气流对地表的侵蚀作用。因此,在防沙治沙工程实施过程中,要充分考虑和利用植被防风抗蚀的生态效应。
英文摘要	【Objective】Influences of typical vegetation communities in desert ecosystems on the aeolian activities in the near surface were studied to reveal soil wind erosion characteristics of desert ecosystem under different underlying surface conditions. 【Method】Five typical underlying surfaces,including semi-fixed dunes (coverage 20%) of Artemisia ordosica,semi-fixed dunes (coverage 30%) of Nitraria tangutorum,fixed dunes (coverage 40%) of A. ordosica and fixed dunes (coverage 40%) of N. tangutorum,and mobile sand dunes (served as the control),were selected in the desert-oasis ecotone at the northeast margin of the Ulanbuh desert. By using the wind erosion brazing and sand flow acquisition system,five kinds of underlying surfaces wind erosion dynamic were real-time monitored to quantitatively analyze the differences of soil wind erosion,vertical distribution and grain size composition under the different underlying surface conditions. 【Result】Soil wind erosion thickness on different underlying surface during the same period in Ulanbuh desert was mobile sand dunes > semi-fixed dunes of A. ordosica > semi-fixed dunes of N. tangutorum > fixed sand dunes of A. ordosica > fixed sand dunes of N. tangutorum. Sand peristalsis could be observed in mobile sand dunes when the wind speed reached to 4.1 m·s~(-1),and the wind erosion material was able to be collected when the wind reached to 5.1 m·s~(-1). In semi-fixed dunes of A. ordosica,semi-fixed dunes of N. tangutorum,fixed dunes of A. ordosica and fixed dunes of N. tangutorum,the wind erosion happened when wind speed reached to 6.3,6.5,6.8 and 7.9 m·s~(-1), respectively. In the vertical section of 0 - 100 cm on the five bed surfaces,sediment runoff of 67.6% - 90.0% distributed in 30 cm height,carrying airflow in the transport rate expressed as a power function declined with the increase of height,and increased with the increase of wind speed. The grain size composition of the wind erosion in each layer was in a unimodal distribution,with the peak between 250 - 100 mum; The peak value of the grain size composition in 0 - 20 cm height layers was obviously different from that of the other layers,and tended to be larger. From below to top,the proportions of very fine sand particles showed an increasing trend,but the proportions of medium sand grain size showed a decreasing trend. 【Conclusion】With the increase of vegetation coverage,soil wind erosion decreased significantly,and the annual wind erosion depth of mobile sand dunes,semi-fixed dunes and fixed sand dunes decreased. With coverage of 40% A. ordosica and N. tangutorum community,the soil wind erosion depth was only about 1.73% - 1.52% of the wind erosion depth of mobile sand dunes at the same time,and the sediment transport rate in the range of 0 - 100 cm height was only 6.6% - 5.1% transport rate of mobile dune sand. Vegetation alleviated stream erosion to the surface mainly by covering the surface,increasing the roughness of the underlying surface and blocking the movement of sand. Therefore,in the process of implementing anti-desertification project,we should fully consider and use the ecological effects of vegetation in resisting wind erosion.
中文关键词	风沙流结构 ; 输沙率 ; 土壤风蚀 ; 粒度分析 ; 乌兰布和沙漠
英文关键词	sand flow structure sand transport rate soil wind erosion size analysis Ulanbuh desert
语种	中文
国家	中国
收录类别	CSCD
WOS类目	FORESTRY
WOS研究方向	Forestry
CSCD记录号	CSCD:5982179
来源机构	中国林业科学研究院沙漠林业实验中心
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/236262
作者单位	中国林业科学研究院沙漠林业实验中心, 内蒙古磴口荒漠生态系统定位观测研究站, 磴口, 内蒙古 015200, 中国
推荐引用方式 GB/T 7714	刘芳,郝玉光,辛智鸣,等. 乌兰布和沙区不同下垫面的土壤风蚀特征[J]. 中国林业科学研究院沙漠林业实验中心,2017,53(3):128-137.
APA	刘芳.,郝玉光.,辛智鸣.,徐军.,黄雅茹.,...&孙非.(2017).乌兰布和沙区不同下垫面的土壤风蚀特征.林业科学,53(3),128-137.
MLA	刘芳,et al."乌兰布和沙区不同下垫面的土壤风蚀特征".林业科学 53.3(2017):128-137.