干旱区生态环境知识资源中心(Arid): 黄土夹砂层的持水机制

Arid

	黄土夹砂层的持水机制
其他题名	Water-holding mechanism of sand layer in loess
	陈建生; 张健; 詹泸成; 黄德文; 张超; 张家甫
来源期刊	河海大学学报. 自然科学版
ISSN	1000-1980
出版年	2016
卷号	44 期号:5 页码:412-417
中文摘要	为研究黄土高原西北干旱区农业采用的压砂保墒方法机理,进行3种室内土柱(均质土柱、夹3 cm厚砂层的土柱、夹5 cm厚砂层的土柱)的降雨入渗试验,并建立微观模型对夹砂层阻水现象进行分析。通过烘干法和MAT253稳定气体同位素质谱仪测定土柱不同深度2个时间点(13 d、197 d)的含水率和土壤水的deltaD、delta~(18) O,得到不同时间含水率随深度变化规律和土壤水deltaD~delta~(18)O关系。结果表明:(a)黄土中夹砂层的存在起到了减缓水流下渗的作用,而不是阻止水分下渗。 (b)夹砂层的这种阻水效果一方面是由于砂层薄膜水的持水量远小于黄土,从而阻滞了水流的下渗;另一方面是由于在介质突变界面处过水断面面积突然减小,以致降低了水流的下渗速度。
英文摘要	In order to study the mechanism of agricultural soil moisture conservation through sand injection in the northwest arid region of the Loess Plateau, rainfall infiltration tests on three kinds of indoor soil columns (a homogeneous soil column, a soil column with a 3 cm-thick sand layer, and a soil column with a 5 cm-thick sand layer) were performed, and the water-resisting phenomenon of the sand layer was analyzed through establishment of a micro model. The water contents in different layers of soil columns at two times (13 days and 197 days) and the deltaD and delta~(18) O values of soil water were measured with the drying method and MAT253 gas isotope ratio mass spectrometer. The change in water content with the depth and the relationship between deltaD and delta~(18) O of soil water were obtained. The results show that the sand layer can retard water infiltration rather than prevent water infiltration. The reasons for this are that the water-holding capacity of sand is far less than that of loess, retarding water infiltration, and the sudden decrease in the wetted cross-sectional area at the interface with abruptly changed medium causes the water infiltration velocity to decrease.
中文关键词	黄土夹砂层 ; 含水率 ; 同位素 ; 持水机制 ; 微观层面 ; 薄膜水运移
英文关键词	sand layer in loess water content isotope water-holding mechanism micro level film water migration
语种	中文
国家	中国
收录类别	CSCD
WOS类目	AGRICULTURAL ENGINEERING
WOS研究方向	Agriculture
CSCD记录号	CSCD:5859179
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/234469
作者单位	河海大学土木与交通学院, 南京, 江苏 210098, 中国
推荐引用方式 GB/T 7714	陈建生,张健,詹泸成,等. 黄土夹砂层的持水机制[J],2016,44(5):412-417.
APA	陈建生,张健,詹泸成,黄德文,张超,&张家甫.(2016).黄土夹砂层的持水机制.河海大学学报. 自然科学版,44(5),412-417.
MLA	陈建生,et al."黄土夹砂层的持水机制".河海大学学报. 自然科学版 44.5(2016):412-417.