Overcoming Data Scarcity Related Issues for Landslide Susceptibility Modeling with Machine Learning

peer reviewedLandslide susceptibility maps can be a useful tool to support holistic urban planning in mountainous environments. Data-driven methods for landslide susceptibility modeling work well even in data scarce areas, and there is an increasing relevance of machine learning methods that help analyze efficiently large and complex datasets. In this contribution we present some of our study examples to show how data quality, quantity, complexity, and preparation can have major effects on the outcomes of landslide susceptibility modeling. The aforementioned aspects are too often neglected in spite of their relevance, both in data scarce, but also data rich areas. We also use these examples to discuss the way we evaluate landslide susceptibility models, as the spatial performance of landslide susceptibility maps often differs from the mathematical performance. We finally discuss the necessity of standards for input data, modeling results and result communication to improve the usability of landslide susceptibility models in urban planning

Movement detectors provide sufficient information for local computation of 2-D velocity field

Reichardt W, Egelhaaf M, Schlögel RW. Movement detectors provide sufficient information for local computation of 2-D velocity field. Naturwissenschaften. 1988;75(6):313-315

SENSOR- AND SCENE-GUIDED INTEGRATION OF TLS AND PHOTOGRAMMETRIC POINT CLOUDS FOR LANDSLIDE MONITORING

Terrestrial and airborne 3D imaging sensors are well-suited data acquisition systems for the area-wide monitoring of landslide activity. State-of-the-art surveying techniques, such as terrestrial laser scanning (TLS) and photogrammetry based on unmanned aerial vehicle (UAV) imagery or terrestrial acquisitions have advantages and limitations associated with their individual measurement principles. In this study we present an integration approach for 3D point clouds derived from these techniques, aiming at improving the topographic representation of landslide features while enabling a more accurate assessment of landslide-induced changes. Four expert-based rules involving local morphometric features computed from eigenvectors, elevation and the agreement of the individual point clouds, are used to choose within voxels of selectable size which sensor’s data to keep. Based on the integrated point clouds, digital surface models and shaded reliefs are computed. Using an image correlation technique, displacement vectors are finally derived from the multi-temporal shaded reliefs. All results show comparable patterns of landslide movement rates and directions. However, depending on the applied integration rule, differences in spatial coverage and correlation strength emerge

Writing Europe : the Dutch case

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Sensor- and scene-guided integration of TLS and photogrammetric point clouds for landslide monitoring

open7siTerrestrial and airborne 3D imaging sensors are well-suited data acquisition systems for the area-wide monitoring of landslide activity. State-of-the-art surveying techniques, such as terrestrial laser scanning (TLS) and photogrammetry based on unmanned aerial vehicle (UAV) imagery or terrestrial acquisitions have advantages and limitations associated with their individual measurement principles. In this study we present an integration approach for 3D point clouds derived from these techniques, aiming at improving the topographic representation of landslide features while enabling a more accurate assessment of landslide-induced changes. Four expert-based rules involving local morphometric features computed from eigenvectors, elevation and the agreement of the individual point clouds, are used to choose within voxels of selectable size which sensor’s data to keep. Based on the integrated point clouds, digital surface models and shaded reliefs are computed. Using an image correlation technique, displacement vectors are finally derived from the multi-temporal shaded reliefs. All results show comparable patterns of landslide movement rates and directions. However, depending on the applied integration rule, differences in spatial coverage and correlation strength emerge.openT. Zieher, I. Toschi, F. Remondino, M. Rutzinger, Ch. Kofler, A. Mejia-Aguilar, R. SchlögelZieher, T.; Toschi, I.; Remondino, F.; Rutzinger, M.; Kofler, Ch.; Mejia-Aguilar, A.; Schlögel, R

Past and potential future socioeconomic impacts of environmental hazards in Kyrgyzstan

This chapter presents an overview on the past socioeconomic impacts of natural hazards, locally combined with severe ecological consequences, in Kyrgyzstan, starting with the end of the 19th century. It will also provide a prospective view on the type of natural events that could have major impacts with nationwide consequences. The analysis of past events shows that compared, e.g., to countries in Western Europe the environmental situation of this relatively small Central Asian country is clearly aggravated through the regular occurrence of multiple geological hazards. Those hazards include numerous disastrous landslides that occur almost every year, and strong (M > 6.3) to very strong (M > 7) earthquakes that are observed once per decade or once per quarter-century, respectively. The review of past events will show that some past earthquakes had fundamental impacts on the governmental structure; this is exemplified by the change of name of the present capital of Kyrgyzstan, Bishkek, in connection with the reconstruction of the city after major impacting seismic events. In this regard, it is important to situate Kyrgyzstan in the general Central Asian context as similar governmental impacts occurred also in the neighbouring countries. The second factor increasing environmental hazards at local or subregional scale is related to the presence of mining and nuclear waste tailings and dumps in several areas distributed all over the country. Here, we will focus on some hotspots such as the Mailuu-Suu River valley. In those areas, ecological disasters are closely depending on natural hazard impacts. Due to the combined presence of multiple types of waste and of active landslides that can be reactivated by earthquakes, most efforts of environmental hazard remediation are presently concentrated on those areas, partly with support of multi-million USD projects. Finally, a third point will be highlighted as it will have the most predictable future negative impacts in many parts of the country - those related to climate change on the water resources and multiple highmountain hazards (snow avalanches, glacier lakes, landslide dam stability and outburst floods). Those impacts can be considered as the most predictable ones as climate change cannot be denied anymore; therefore, related hazards are less aleatory than those induced by geological hazards, earthquakes, in particular. Some changing high-mountain hazards are also likely to impact more and more the aforementioned environmental hotspots in Kyrgyzstan, including also dam structures and reservoirs, through the intermediate of increased flood hazards. Providing a quantitative verification of social and economic impacts of geological, climatic and general environmental hazards is not always possible. Therefore, part of the chapter will be dedicated to a critical analysis of available statistics describing those impacts. This is necessary in order to make reliable predictions of future consequences of hazards that also need to take into account the social changes to which Kyrgyzstan is exposed: rural exodus, decreasing general population, changing economic situation of private persons and public institutions, as well as the changing risk perception in the population. © 2017 Nova Science Publishers, Inc

Structural control on the kinematics of the deep-seated La Clapière landslide revealed by L-band InSAR observations

International audienceThe objective of this work is to document the deformation pattern of the deep-seated La Clapière landslide for the period 2007–2010 from the combination of L-band synthetic aperture radar (SAR) interferograms, ground-based total station measurements and identification of the slope geomorphological structures. The interferograms are calculated for pairs of ALOS/PALSAR images at a time interval of 46 days. The displacement field derived from the interferograms reveals a non-uniform displacement gradient from the top (subsidence) to the bottom (accumulation). Vertical velocities are calculated from the unwrapped phase values and are in good agreement with ground-based measurements. The results demonstrate the potential of L-band ALOS/PALSAR imagery for the monitoring of active landslides characterized by complex kinematic patterns and by important changes in the soil surface backscattering in time

Movement detectors of the correlation type provide sufficient information for local computation of the 2-D velocity field

Reichardt W, Schlögel RW, Egelhaaf M. Movement detectors of the correlation type provide sufficient information for local computation of the 2-D velocity field. In: Haken H, ed. Neural and synergetic computers: proceedings of the international symposium at Schloß Elmau, Bavaria, June 13 - 17, 1988. Springer series in synergetics ; 42. Berlin: Springer; 1988: 170-179