Determination of Primary and Secondary Lahar Flow Paths of the Fuego Volcano (Guatemala) Using Morphometric Parameters
Determination of Primary and Secondary Lahar Flow Paths of the Fuego Volcano (Guatemala) Using Morphometric Parameters
复制标题
使用形态参数确定富埃戈火山（危地马拉）的一次和二次火山泥流路径
作者：
M. Cando;A. Martínez
2018年6月3日，危地马拉富埃戈火山强烈喷发，产生10公里高的浓密火山灰云和破坏性的火山碎屑流，导致该地区近200人死亡，造成巨大经济损失。随后，由于大雨，产生了破坏性的次生火山泥浆，而这些火山泥浆并未在使用 LAHAR Z 软件的灾害地图上绘制出来。在这项工作中，我们建议使用哨兵图像 1A 和 2A 中的遥感（差分干涉测量法，DINSAR）来补充此类火山泥浆的测绘，以定位火山侧面地形的变形区域，这些区域可能是这些火山泥浆的起源。为了确定火山泥流的轨迹，使用自动地球科学分析系统（SAGA）软件对参数和形态指数进行了分析。使用的参数和形态指数是累积流量（FCC）、地形湿度指数（TWI）、坡度长度大小因子（LS）。最后，基于莫尔-库仑理论及其参数：内部土壤饱和度和有效降水量，以及破坏山坡稳定所需的参数，使用浅层滑坡敏感性软件（SHALSTAB）进行边坡稳定性分析。在这种情况下，这种补充方法的应用为火山附近被原生和次生火山泥流破坏的区域提供了更准确的响应。
On 3 June 2018, a strong eruption of the Fuego volcano in Guatemala produced a dense cloud of 10-km-high volcanic ash and destructive pyroclastic flows that caused nearly 200 deaths and huge economic losses in the region. Subsequently, due to heavy rains, destructive secondary lahars were produced, which were not plotted on the hazard maps using the LAHAR Z software. In this work we propose to complement the mapping of this type of lahars using remote-sensing (Differential Interferometry, DINSAR) in Sentinel images 1A and 2A, to locate areas of deformation of the relief on the flanks of the volcano, areas that are possibly origin of these lahars. To determine the trajectory of the lahars, parameters and morphological indices were analyzed with the software System for Automated Geoscientific Analysis (SAGA). The parameters and morphological indices used were the accumulation of flow (FCC), the topographic wetness index (TWI), the length-magnitude factor of the slope (LS). Finally, a slope stability analysis was performed using the Shallow Landslide Susceptibility software (SHALSTAB) based on the Mohr–Coulomb theory and its parameters: internal soil saturation degree and effective precipitation, parameters required to destabilize a hillside. In this case, the application of this complementary methodology provided a more accurate response of the areas destroyed by primary and secondary lahars in the vicinity of the volcano.