The importance of digital elevation model resolution on granular flow simulations: a test case for Colima volcano using TITAN2D computational routine
The importance of digital elevation model resolution on granular flow simulations: a test case for Colima volcano using TITAN2D computational routine
复制标题
数字高程模型分辨率对颗粒流模拟的重要性：使用 TITAN2D 计算例程的科利马火山测试案例
DOI：
10.1007/s11069-011-9788-6
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
G. Norini
中科院分区：
文献类型：
--
作者：
L. Capra;V. Manea;M. Manea;G. Norini
重力驱动的颗粒流的流动性，如泥石流或火山碎屑密度流，对地形变化极其敏感，如坡度、障碍物或峡谷偏斜。在危险评估中，计算机代码可以重现过去的事件，并根据自然地形上模拟水流的淹没极限来评估危险区划。数字高程模型(DEM)是模拟算法的常用输入，其再现历史径流的准确性至关重要。在这项工作中，我们使用TITAN2D程序在不同单元大小(5，10，30，50和90米)的DEM上再现了墨西哥科里马火山过去的块状和灰烬流动，以说明分辨率对数值模拟的影响。结果表明，地形分辨率对流动路径和跳动有显著影响。此外，我们还发现，用相同的输入参数(如底摩擦角)模拟不同分辨率的地形上的过去流动时，模拟的流动路径、面积和厚度都不同。特别是，用5米和10米数字高程模型进行的模拟产生了类似的结果。此外，对于30米和50米的DEM，我们也获得了一致的模拟结果。然而，对于较粗的90-m DEM，结果有很大的不同和不准确。我们建议生成一个基准表，以获取所研究事件的基本摩擦角的特征值。在地形崎岖的情况下，应使用高分辨率的DEM以获得更有信心的结果。
The mobility of gravity-driven granular flows such as debris flows or pyroclastic density currents are extremely sensitive to topographic changes, such as break in slopes, obstacles, or ravine deviations. In hazard assessment, computer codes can reproduce past events and evaluate hazard zonation based on inundation limits of simulated flows over a natural terrain. Digital Elevation Model (DEM) is a common input for the simulation algorithm and its accuracy to reproduce past flows is crucial. In this work, we use TITAN2D code to reproduce past block-and-ash flows at Colima volcano (Mexico) over DEMs with different cell size (5, 10, 30, 50, and 90 m) in order to illustrate the influences of the resolution on the numeric simulations. Our results show that topographic resolution significantly affects the flow path and runout. Also, we found that simulations of past flows with the same input parameters (such as the basal friction angle) over topography with different resolutions resulted in different flow paths, areas, and thickness of the simulated flows. In particular, the simulations performed with the 5- and 10-m DEMs produced similar results. Also, we obtained consistent simulation results for the 30- and 50-m DEMs. However, for the coarser 90-m DEM results are largely different and inaccurate. We recommend generating a benchmark table in order to acquire characteristic values for the basal friction angle of studied events. In case of rugged topographies, a DEM with high resolution should be used for more confident results.