Landslide inventory in a rugged forested watershed: a comparison between air-photo and field survey data
Landslide inventory in a rugged forested watershed: a comparison between air-photo and field survey data
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DOI：
10.1016/s0169-555x(02)00355-0
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发表时间：
2003-09
期刊：
影响因子：
3.9
通讯作者：
F. Brardinoni;O. Slaymaker;Marwan A. Hassan
中科院分区：
文献类型：
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作者：
F. Brardinoni;O. Slaymaker;Marwan A. Hassan
山泥倾泻清单是以航空照片判读（API）的方式定期编制的。当检查照片对时，森林树冠（特别是在古老的森林中）隐藏着一群“不可见”的山体滑坡。在本研究中，我们试图估计如何重要的是不可检测的滑坡的贡献，从航空照片到全球大量的沉积物生产的大规模故障的森林地形的Capilano盆地，沿海不列颠哥伦比亚省。API与密集的实地工作相结合，以识别和测量所有山泥倾泻。通过了一个30年框架。我们发现，“不可见”的滑坡可以代表高达85%的故障总数和占30%的体积的碎片动员。这些百分比显示出次盆地的高度变异性，研究区域两个次盆地之间的沉积物生成率相差一个数量级。这是定性地解释了基于GIS的分析的斜坡频率分布，排水密度，和空间分布的表层物质。这些观察结果在运输有限和供应有限流域的定义中得到进一步的支持。作为土地管理人的实际考虑因素，我们预计只有在交通有限的系统中，才必须进行额外的实地工作，以确定山泥倾泻。现场工作表明，与冲沟相关的故障比API所能预期的更为重要。
Landslide inventories are routinely compiled by means of aerial photo interpretation (API). When examining photo pairs, the forest canopy (notably in old-growth forest) hides a population of “not visible” landslides. In the present study, we attempt to estimate how important is the contribution of landslides not detectable from aerial photographs to the global mass of sediment production from mass failures on forested terrain of the Capilano basin, coastal British Columbia. API was coupled with intensive fieldwork for identification and measurement of all landslides. A 30-year framework was adopted. We show that “not visible” landslides can represent up to 85% of the total number of failures and account for 30% of the volume of debris mobilised. Such percentages display high sub-basin variability with rates of sediment production varying by one order of magnitude between two sub-basins of the study area. This is explained qualitatively by GIS-based analysis of slope frequency distributions, drainage density, and spatial distribution of surficial materials. Such observations find further support in the definitions of transport-limited and supply-limited basins. As a practical consideration to land managers, we envisage that supplementary fieldwork for landslide identification is mandatory in transport-limited systems only. Fieldwork has demonstrated that gully-related failures have a greater importance than one could expect from API.