Drainage density, slope angle, and relative basin position in Japanese bare lands from high-resolution DEMs
Drainage density, slope angle, and relative basin position in Japanese bare lands from high-resolution DEMs
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DOI：
10.1016/j.geomorph.2004.03.012
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发表时间：
2004-12
期刊：
影响因子：
3.9
通讯作者：
Zhou Lin;T. Oguchi
中科院分区：
文献类型：
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作者：
Zhou Lin;T. Oguchi
在日本的三个裸露的土地排水密度和坡度之间的关系进行了分析，特别注意在早期侵蚀阶段的渠道和渠道的荒地型地形。其中两块裸露的土地是1年或30-40年前的火山喷发造成的，另一块是100多年前形成的山体滑坡伤痕。光栅数字高程模型（DEM）与1米的分辨率和正射航空照片生成使用数字摄影测量，使详细的流网络提取和地形分析。排水密度，坡度角，和相对高度的88个子流域的DEM和派生流网的数据。各子流域的排水密度与坡度的关系可分为两种类型：向下倾斜型和向上凸起型。虽然以往的研究表明，排水密度正相关的坡度，如果坡面流是占主导地位的，这种关系很少发生在研究地区。这两种类型的排水密度-坡度角关系对应于不同的渠化阶段，反映了现有渠道的扩展和整合，以及新的低阶流的形成，以响应基准面降低。每个研究区域内的子流域的位置似乎发挥了重要作用，在确定渠道发展的阶段，反过来，排水密度-坡度角关系的类型。
Relationships between drainage density and slope angle for three bare lands in Japan were analyzed with special attention to channels at early erosion stages and channels in a badland-type terrain. Two of the bare lands were caused by volcanic eruptions 1 or 30–40 years ago, and the other one is a landslide scar formed more than 100 years ago. Raster digital elevation models (DEMs) with a 1-m resolution and ortho aerial photos were generated using digital photogrammetry to enable detailed stream-net extraction and topographic analyses. Data for drainage density, slope angle, and relative height for 88 subwatersheds were obtained from the DEMs and derived stream-nets. The relationship between drainage density and slope angle for each subwatershed can be divided into two types: downward sloping and convex upward. Although previous studies suggested that drainage density positively correlates with slope angle if overland flow is dominant, this correlation seldom occurs in the study areas. The two types of drainage density–slope angle relationships correspond to differing channelization stages that reflect the extension and integration of existing channels, as well as the formation of new low-order streams in response to base-level lowering. The location of subwatersheds within each study area seems to play a major role in determining the stages of channel development and, in turn, the types of drainage density–slope angle relationships.