Assessment of sediment sources throughout the proglacial area of a small Arctic catchment based on high-resolution digital elevation models
Assessment of sediment sources throughout the proglacial area of a small Arctic catchment based on high-resolution digital elevation models
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基于高分辨率数字高程模型评估北极小流域整个冰河区的沉积物来源
DOI：
10.1016/j.geomorph.2016.09.011
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发表时间：
2017
期刊：
影响因子：
3.9
通讯作者：
W. Kociuba
中科院分区：
文献类型：
--
作者：
W. Kociuba
本文通过(i)确定重要沉积物来源的空间分布，（ii）评估沉积物体积和地貌形态的时空变化，以及（iii）评估特定子系统在沉积物分布中的作用，对冰谷选定子系统形态的定量修正进行了计算。该研究比较了2010年至2013年在斯匹次卑尔根岛西北Wedel Jarlsberg地的斯科特冰川集水区（10.1平方公里）进行的实地测量结果。地形表面变化的评估是通过精确的地面激光扫描（TLS）调查来完成的。斜向激光扫描的应用现场和后处理技术允许获取分辨率为0.01 m和密度为500pt m−2的数字高程数据。这允许开发详细的地形模型，并平衡六个研究试验区（10,000平方米）的空间定量变化，这些试验区位于汇水的两个子系统中，呈梯级排列。在冲积谷底子系统中，调查范围包括：1)冰川末端，2)边缘内冲积平原，3)边缘外辫状平原和4)冲积扇；在斜坡子系统中，调查范围包括：5)通过终端冰碛形成的峡谷侵蚀-沉积斜坡，6)溶蚀斜坡。在两个分析的山谷子系统中，根据地貌过程的时空动态区分出三个不同的区域。在谷底子系统中，它们是：(i)基本补给区（分布在整个融化季节）和（ii）再沉积区（分布在洪水期间）；在斜坡子系统中，（iii）周期性补给区（主要分布在夏季降水增加和气温快速上升的时期以及冬季雪崩期间）。在短/3年的时间尺度上，冰川、河道和谷底的地貌以及由于大量的浪费过程和活跃的永久冻土层的活动而搬运的斜坡沉积物构成了沉积物供应的重要来源。地表形态（斜坡、洪泛平原和河道平台）的重大变化导致了泥沙收支的变化。对位于冲积谷子系统的试验区的连续dem进行减法，揭示了下游的空间和体积差异，从侵蚀优势（占体积的79%，占面积的43%）到底部上部的沉积优势（分别为90/91%），再到底部中部（88/95%）和底部（87/82%）的侵蚀优势。位于斜坡分系统的试验区表现出相反的关系：峡谷上游以沉积为主（占体积的88%，占面积的80%），下游（溶蚀坡）以侵蚀为主（分别占99/99%）。对短时间重复调查（3周调查）的分析显示，冲积扇和溶蚀坡的沉积增加（分别占体积的82%和面积的79%）（分别占70%和57%）。
The article presents calculations of quantitative modifications of the morphology of selected subsystems of a glacial valley through: (i) identification of the spatial distribution of important sources of sediment, (ii) assessment of the spatiotemporal variety of sediment volume and landform morphology, and (iii) assessment of the role of particular subsystems in sediment distribution. The study involved a comparison of the results of field measurements from 2010 to 2013 performed in the Scott Glacier catchment (10.1 km2) in NW Wedel Jarlsberg Land (Spitsbergen). The assessment of the landform surface changes was performed by means of a precise Terrestrial Laser Scanning (TLS) survey. The applied field and post-processing techniques for oblique laser scanning permitted the acquisition of digital elevation data at a resolution 0.01 m and density > 500 pt m− 2. This allowed the development of a detailed terrain model, and balancing spatial quantitative changes in six research test areas (10,000 m2) located within two subsystems of the catchment in a cascade arrangement. In the alluvial valley-floor subsystem, the survey covered: 1) the glacier terminus, 2) the intramarginal outwash plain, 3) the extramarginal braid-plain and 4) the alluvial fan, and in the slope subsystem: 5) the erosional-depositional slope in the gorge through terminal moraines, and 6) the solifluction slope. Three zones differing in terms of the spatiotemporal dynamics of geomorphic processes were distinguished within the two analysed valley subsystems. In the valley floor subsystem, these are: (i) the zone of basic supply (distribution throughout the melting season) and (ii) the redeposition zone (distribution particularly during floods), and in the slope subsystem: (iii) zone of periodical supply (distributed mainly in periods of increased precipitation and rapid increases in temperature in summer and during snow avalanches in winter). The glacier and the landforms of the channel and valley floor, as well as slope sediments transported as a result of mass wasting processes and activity of the active permafrost layer, constitute important sources of sediment supply over a short/3-year timescale. Evidence of major changes of the surface morphology (slopes, floodplain and channel platform) resulted in varied sediment budgets. The subtraction of consecutive DEMs of the test areas located in the alluvial valley subsystem revealed downstream spatial and volumetric differentiation, from the predominance of erosion (79% of volume; 43% of area) to the dominance of deposition (90/91%, respectively) in upper part of the valley floor to erosion predominance in the central (88/95%) and lower (87/82%) part of valley floor. The test areas located on the slope subsystem showed the opposite relationship: deposition dominance (88% of volume; 80% of area) in the upper gorge and erosion dominance (99/99%, respectively) in the lower part (solifluction slopes). The analysis of short-time repeated surveys (3-week survey) where volumes were calculated following DEM subtraction showed increased deposition (82% of volume; 79% of area) for the alluvial fan, and for solifluction slopes (70/57%, respectively).
事件后不平衡状态下高山沉积物储量的变化及其对下游水文和底质输送的影响
DOI：
10.1080/00291950802095079
发表时间：
2008
期刊：
Norsk Geografisk Tidsskrift - Norwegian Journal of Geography
影响因子：
--
作者：
Morche;Schmidt;Sahling;Herkommer;Kutschera
通讯作者：
Kutschera
影响因子：
3.9
作者：
Bremer, Magnus;Sass, Oliver
通讯作者：
Sass, Oliver