A linked geomorphological and geophysical modelling methodology applied to an active landslide
A linked geomorphological and geophysical modelling methodology applied to an active landslide
复制标题
DOI：
10.1007/s10346-021-01666-w
复制
发表时间：
2021-05-05
期刊：
影响因子：
6.7
通讯作者：
Binley, Andrew
中科院分区：
文献类型：
--
作者：
Boyd, Jimmy;Chambers, Jonathan;Binley, Andrew
湿气引起的滑坡是一种全球性的地质灾害;减轻滑坡造成的风险需要了解特定斜坡内的水文和地质条件。近年来，许多地球物理研究试图探测缓慢移动的滑坡，重点是发展地电方法作为水文监测工具。然而，滑坡对在长期监测环境中处理地电数据提出了具体的挑战，因为传感器阵列可以随着斜坡移动而移动。在这里，我们提出了一种方法，用于处理长期（超过8年）的地电监测数据，从一个活跃的缓慢移动的滑坡，Hollin山，位于Lias岩石在南部的豪沃山，英国。这些斜坡移动扭曲了监测阵列的初始设置，需要纳入延时电阻率处理工作流程，以避免成像伪影。我们回顾了七个数字地形模型，以告知我们的成像体积的地形，这些地形是由基于无人机（UAV）的摄影测量或地面激光测距系统获得的。一个不规则的网格木钉定期调查与全球定位系统，从扭曲的地形模型和电极的位置可以模拟薄板样条。为了有效地模拟时间序列电阻率图像，在反演方案中应用了基线约束;研究的结果是一个时间推移系列的电阻率体积，其中也包括斜坡运动。这里提出的工作流程应适用于其他研究，侧重于地球物理/岩土监测不稳定的斜坡。
Moisture-induced landslides are a global geohazard; mitigating the risk posed by landslides requires an understanding of the hydrological and geological conditions present within a given slope. Recently, numerous geophysical studies have been attempted to characterise slow-moving landslides, with an emphasis on developing geoelectrical methods as a hydrological monitoring tool. However, landslides pose specific challenges for processing geoelectrical data in long-term monitoring contexts as the sensor arrays can move with slope movements. Here we present an approach for processing long-term (over 8 years) geoelectrical monitoring data from an active slow-moving landslide, Hollin Hill, situated in Lias rocks in the southern Howardian Hills, UK. These slope movements distorted the initial setup of the monitoring array and need to be incorporated into a time-lapse resistivity processing workflow to avoid imaging artefacts. We retrospectively sourced seven digital terrain models to inform the topography of our imaging volumes, which were acquired by either Unmanned Aerial Vehicle (UAV)-based photogrammetry or terrestrial laser ranging systems. An irregular grid of wooden pegs was periodically surveyed with a global position system, from which distortions to the terrain model and electrode positions can be modelled with thin plate splines. In order to effectively model the time-series electrical resistivity images, a baseline constraint is applied within the inversion scheme; the result of the study is a time-lapse series of resistivity volumes which also incorporate slope movements. The workflow presented here should be adaptable for other studies focussed on geophysical/geotechnical monitoring of unstable slopes.