Identification of Micro-Scale Landforms of Landslides Using Precise Digital Elevation Models

Julián Tomaštík,Martin Mokroš,Martina Slámová,František Chudý,Roberta Prokešová

doi:10.3390/geosciences9030117

Abstract

An active gully-related landslide system is located in a deep valley under forest canopy cover. Generally, point clouds from forested areas have a lack of data connectivity, and optical parameters of scanning cameras lead to different densities of point clouds. Data noise or systematic errors (missing data) make the automatic identification of landforms under tree canopy problematic or impossible. We processed, analyzed, and interpreted data from a large-scale landslide survey, which were acquired by the light detection and ranging (LiDAR) technology, remotely piloted aircraft system (RPAS), and close-range photogrammetry (CRP) using the ‘Structure-from-Motion’ (SfM) method. LAStools is a highly efficient Geographic Information System (GIS) tool for point clouds pre-processing and creating precise digital elevation models (DEMs). The main landslide body and its landforms indicating the landslide activity were detected and delineated in DEM-derivatives. Identification of micro-scale landforms in precise DEMs at large scales allow the monitoring and the assessment of these active parts of landslides that are invisible in digital terrain models at smaller scales (obtained from aerial LiDAR or from RPAS) due to insufficient data density or the presence of many data gaps.

Highlights

Applications of Remote Sensing Technologies in Multiscale Surveys of Small LandslidesUndetected landslides may be considered as elements at risk if they threaten urbanized areas and related infrastructure [1]
In a field survey beneath a densely vegetated area, data acquired by the light detection and ranging (LiDAR) technology proved to be of high density and quality [9]
The model was constructed from the following overlaid raster files: digital elevation models (DEMs) derived from LiDAR point clouds, topographic wetness index, and sky-view factor highlighting shades and lights of sharply-curved landforms

Summary

Introduction

Applications of Remote Sensing Technologies in Multiscale Surveys of Small LandslidesUndetected landslides may be considered as elements at risk if they threaten urbanized areas and related infrastructure [1]. Applications of Remote Sensing Technologies in Multiscale Surveys of Small Landslides. Remote sensing techniques are commonly used to detect, map, and monitor slope failures [2,3,4,5,6,7]. Recognizing micro-scale landforms indicative for slope instabilities as tension cracks, minor scarps, or undulating terrain remains a challenge for field surveys performed by remote sensing technologies, especially when forested and rugged terrains are subjects of field surveys [8]. Each landslide investigation requires properly designed methodology, even when conventional technologies are applied. In a field survey beneath a densely vegetated area, data acquired by the light detection and ranging (LiDAR) technology proved to be of high density and quality [9]. An Geosciences 2019, 9, 117; doi:10.3390/geosciences9030117 www.mdpi.com/journal/geosciences

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