摘要
泥沙颗粒特征是表征泥沙表面形态、泥沙机械组成、排列模式及泥沙絮凝现象的主要物理属性之一。在水土流失严重的水蚀风蚀交错区,不同地表覆被类型的侵蚀产沙方式和粗泥沙的侵蚀产沙强度很不均衡,导致其泥沙粒径分布的差异很大。以黄土高原典型淤地坝为例,采用分形原理和多重分形理论研究淤地坝坝控小流域泥沙粒径的分形特征,结果表明:淤地坝坝内泥沙与坡面泥沙存在线性关系,相关系数高达0.93;泥沙粒径分形维数D在淤地坝坝内垂直方向上随泥沙颗粒的增大而减小;分形的5个特征参数D,D(0),D(1),D(2),D(0)/D(1)均表明不同地表覆被类型下,草地的粒度分布较均匀,裸地次之,分布最狭窄的是砂岩,该结果可为小流域泥沙来源和水土保持治理措施提供重要依据。
Grain size is one of the most important physical attributes due to its influence on sediment proper- ties related to surface morphology of sediment, the mechanical composition of sediment, the arrangement of grains and flocculation of cohesive of sediment. So in the water-wind erosion crisscross region, ways of sedi- ment generation have strong discrepancy with different patterns of surface cover, which lead to the differ- ences in grain size distribution. In this paper, special dam on the Loess Plateau was taken as an example. The fractal dimension and multifractal theory were applied to study the fractal characteristics of grain size distribution in the checkdam and potential sediment sources. The results show that a good linear relationship between the sediment deriving from the slope and the sediment which deposited in the checkdam were found. Fractal dimension （D） in the checkdam decrease with the increase of sediment particles in the vertical direc tion. The same result is reflected by the five parameters such as D, D（O）, D（1）, D（2）, D（O）/D（1）. Under different types of surface cover, the grain size distribution of the grassland is uniform, bare land is the sec- ondary, and the most narrow distribution is observed in sandstone. So the grassland, bare land and sand- stone can allow the determination of sediment sources. Our results could be used to study the sediment source of small watershed and provide an important basis with soil and water conservation.
出处
《水土保持研究》
CSCD
北大核心
2014年第1期12-17,共6页
Research of Soil and Water Conservation
基金
中国科学院重点部署项目"近百年黄土高原侵蚀环境与水沙变化"(KZZD-EW-04)
国家自然科学基金"皇甫川流域泥沙来源的复合指纹示踪研究"(41201266)
中国科学院2011年西部之光项目"气候变化与人类活动对皇甫川水沙变化贡献的定量评价(2011ZD03)
关键词
淤地坝
泥沙粒径
分形维数
多重分形
黄土高原
checkdam
sediment size
fractal dimension
multifractal characteristics
Loess Plateau
