Identification of postglacial dissection fronts using high-resolution DEMs and applications to geomorphological development

冰后期切割锋是日本更新世-全新世过渡期降雨强度突然增加而形成的山坡上的沟状地形。在整个全新世，锋面一直在后退。因此，坡面前缘可作为坡面分类、坡面泥沙供应量估算和坡面失稳预报的重要指标。由于前方的识别是根据航空照片判读进行的，因此结果可能因个人因素而有所不同。因此，本研究尝试使用高分辨率数字高程模型（DEM），其可用性近年来一直在增加的自动识别的前。锋面的识别需要准确地推导河网及其特性，提取主流的纵剖面，识别相对陡的河段，并分析流域的横剖面。 ...更多信息 文件.由于这些类型的基础研究是必不可少的，以达到最终的目标，自动识别冰后期解剖锋，本研究花了很长的时间和大量的努力，基础研究，包括方法的发展。然后，新开发的方法被应用到三个日本裸地（乌苏，草津白根和赤Kuzure）和三个广泛的丘陵和山区（多摩，滨田和盐尻地区）。基于DEM的地形分析也适用于一些地貌上的重要问题，即使它们不直接相关的冰后期解剖前。此外，在研究项目的早期阶段审查了现有的相关研究。虽然一些基本的地形分析方法，如推导山坡的角度和曲率，已经建立了DEM，以前的研究很少处理复杂的地形要素，在这项研究中。因此，本研究的基本尝试，提供一些通用的地貌分析方法，似乎是有意义的。少

The postglacial dissection front is a ditch-like topography on a hillslope formed in response to abrupt increase in rainfall intensity during the Pleistocene-Holocene transition in Japan. The front has been retreating throughout the Holocene. Therefore, the front can be regarded as an important indicator for hillslope classification, estimation of hillslope sediment supply, and prediction of slope failure in the near future. Because identification of the front has been performed based on airphoto interpretation, the results may differ depending on personal factors. Therefore, this study attempts the automatic identification of the front using high-resolution digital elevation models (DEMs), whose availability has been increasing in recent years. The identification of the front requires accurate derivation of stream-nets and their properties, extraction of longitudinal profiles of master streams, identification of relatively steep river segments, and analysis of watershed transverse pro … More files. As these types of basic research is indispensable to reach the final aim, automatic identification of the postglacial dissection front, this study spent a long time and lots of efforts for basic research including the development of methodologies. Then the newly developed methods were applied to three Japanese barelands (Usu, Kusatsu-Shirane and Aka-Kuzure) and three broad hilly lands and mountains (Tama, Hamada and Shiojiri regions). DEM-based terrain analysis was also applied to some geomorphologically important issues even if they are not directly related to the postglacial dissection front. In addition, existing relevant studies were reviewed at the early stage of the research project. Although some basic methods of terrain analysis using DEMs, such as derivation of hillslope angles and curvature have been established, previous studies have rarely dealt with complex topographic elements as examined in this study. Therefore, basic trials in this study to provide some universal methods for geomorphological analyses seem to be meaningful. Less