【摘要】 黄土沟谷是黄土高原物质和能量交换最频繁、形态和形状变化最剧烈的区域。黄土沟沿线作为沟蚀的重要地形特征线,是研究黄土沟蚀特征的重要切入点。该文以黄土峁区(窑家湾)、黄土梁区(安塞)和黄土塬区(长武)3个典型小流域为研究样区,以低空摄影测量生成的1 m分辨率DEM为实验数据,采用集合经验模态分解(EEMD)-瞬时频率变换方法分析各样区黄土沟沿线地形剖面的变化特征。结果表明,黄土高原不同地貌类型区沟沿线地形剖面变化特征差异明显,各样区的沟蚀活跃区多分布于沟头,沟蚀方式以沟头的溯源侵蚀最为活跃,反映了黄土高原地貌的发育进程和沟蚀活跃性,3个样区中黄土梁区(安塞)的沟蚀和沟谷发育最活跃,与实地调查结果一致。更多还原

【Abstract】 Gully is characterized by the frequent material exchange and strong morphological changes in the Loess Plateau.As an important topographic characteristic line of gully erosion, the shoulder line is an important entry point to study the characteristics of loess gully erosion.In this paper, three typical topographic loess watersheds in the loess hill area(Yaojiawan),loess ridge area(Ansai) and the loess tableland area(Changwu) were used as the study sample regions, and the 1 m resolution DEM generated by low-altitude photogrammetry was used as the experiment data.The EEMD-instantaneous frequency transform was used to analyze the variation characteristics of the terrain profiles of the shoulder lines.The results show that there are obvious differences in the variation characteristics of the shoulder line profiles in different geomorphic regions of the Loess Plateau.Most of the active gully erosion areas are distributed at the gully head.As the most active gully erosion mode in the Loess Plateau, the headward erosion can not only reflect the gully erosion activity of the Loess Plateau, but also reflect the landform development process of the Loess Plateau.Among the three sample regions, the gully erosion in the loess ridge area(Ansai) is the strongest, and the gully development is the most active, which is consistent with the results of field investigation.EEMD-instantaneous frequency transform can be applied to the processing of nonlinear and unstable characteristic signals in the Loess Plateau, and has certain theoretical and practical value for quantifying the instantaneous frequency about shoulder lines of different geomorphologic types.更多还原