Morphological Changes Detection of a Large Earthflow Using Archived Images, LiDAR-Derived DTM, and UAV-Based Remote Sensing

Massimo Conforti,Luigi Borrelli,Michele Mercuri

doi:10.3390/rs13010120

Abstract

In mountainous landscapes, where strongly deformed pelitic sediments outcrop, earthflows can dominate denudation processes and landscape evolution. This paper investigated geological and geomorphological features and space-time evolution over a 65-year time span (1954–2019) of a large earthflow, representative of wide sectors of the Apennine chain of southern Italy. The landslide, with a maximum length of 1.85 × 103 m, affects an area of 4.21 × 105 m2 and exhibits two source zones: a narrow and elongated transport zone and a lobate accumulation zone. Spatial and temporal morphological changes of the earthflow were assessed, comparing multi-source and multi-temporal data (aerial photographs, Google Earth satellite images, Light Detection and Ranging (LiDAR) and Unmanned Aerial Vehicles (UAV) system data). Geomorphic changes, quantified using Digital Terrain Models (DTMs) of differences, highlighted an extensive lowering of the topographic surface in the source area and a significant uplift at the landslide toe. Moreover, the multi-temporal analysis showed a high increase of landslide surface (more than 66%) during the last 65 years. The volumetric analyses showed that different sectors of the earthflow were active at different times, with different rates of topographic change. Overall, the used approach highlighted the great potentiality of the integration of multi-source and multi-temporal data for the diachronic reconstruction of morphological landslide evolution.

Highlights

Earthflows are among the most common and widespread mass movement phenomena in nature; they occur in many of the world’s hilly and mountainous areas [1,2,3] where they represent the primary agent of erosion and contribute large amounts of sediment to streams and rivers [4]
The geologicalsetting settingof ofthe thestudy studycatchment catchment
For the landslide investigated in this work, the entity of displacements of mass movements is of the same order of magnitude as the accuracy of historical aerial photos

Summary

Introduction

Earthflows are among the most common and widespread mass movement phenomena in nature; they occur in many of the world’s hilly and mountainous areas [1,2,3] where they represent the primary agent of erosion and contribute large amounts of sediment to streams and rivers [4]. Such type of landslides can cause extensive damage to property and infrastructure [5,6,7]. Pulses of movements characterize the temporal behavior of the earthflows, which exhibit relatively short periods of intense activity followed by longer quiescent periods of reduced or no measurable movement [5,16,17]

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Conclusion