scholarly journals Practical Estimation of Landslide Kinematics Using PSI Data

Geosciences ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 214
Author(s):  
Chiara Crippa ◽  
Federico Agliardi

Kinematics is a key component of a landslide hazard because landslides moving at similar rates can affect structures or collapse differently depending on their mechanisms. While a complete definition of landslide kinematics requires integrating surface and subsurface site investigation data, its practical estimate is usually based on 2D profiles of surface slope displacements. These can be now measured accurately using Persistent Scatterer InSAR (PSI), which exploits open access satellite imagery. Although 2D profiles of kinematic quantities are easy to retrieve, the efficacy of possible descriptors and extraction strategies has not been systematically compared, especially for complex landslides. Large, slow rock slope deformations, characterized by low displacement rates (<50 mm/year) and spatial and temporal heterogeneities, are an excellent testing ground to explore the best approaches to exploit PSI data from Sentinel-1 for kinematic characterization. For three case studies, we extract profiles of different kinematic quantities using different strategies and evaluate them against field data and simplified numerical modelling. We suggest that C-band PSI data allow for an effective appraisal of complex landslide kinematics, provided that the interpretation is (a) based on decomposed velocity vector descriptors, (b) extracted along critical profiles using interpolation techniques respectful of landslide heterogeneity, and (c) constrained by suitable model-based templates and field data.

Author(s):  
A. Buda ◽  
S. Mauri

<p><strong>Abstract.</strong> Historic buildings are fragile systems to be managed and protected during time: in the task of heritage restoration, efficiency improvement interventions should enable a more sustainable building conservation and use. Such measures might be defined within the combination of building survey and energy performance simulation. A good knowledge of materials and physics characteristics is fundamental to weigh correctly any improvement intervention. This can be supported also by documentary research and diagnostics, to detect existing resources and conservation issues. However, how to match all collected qualitative and quantitative data with a building energy model is still an open question. Energy simulation alone gives a partial vision of heritage needs, excluding information which do not affect the thermal performance of the model; on the contrary, a whole building approach is necessary for defining restoration interventions. With the aim of suggesting a methodology to combine both fields of investigation, a case study has been chosen to our purpose: Giuseppe Terragni’s Casa del Fascio (1936). A multidisciplinary process with the combination of building survey, monitoring campaign, on-site investigation and energy modelling has been functional to the understanding of the real building needs and the definition of interventions. Furthermore, the analysis has given to the rediscover of Terragni’s microclimatic control system (not more existing), leading to the choice of reinventing - in a modern way – the existing devices (as curtains), well-balanced on building needs.</p>


2021 ◽  
pp. 1-14
Author(s):  
Alessandro Medeiros ◽  
Andreza Sartori ◽  
Stfano Frizzo Stefenon ◽  
Luiz Henrique Meyer ◽  
Ademir Nied

Contamination in insulators results in an increase in surface conductivity. With higher surface conductivity, insulators are more vulnerable to discharges that can damage them, thus reducing the reliability of the electrical system. One of the indications that the insulator is losing its insulating properties is its increase in leakage current. By varying the leakage current over time, it is possible to determine whether the insulator will develop an irreversible failure. In this way, by predicting the increase in leakage current, it is possible to carry out maintenance to avoid system failures. For forecasting time series, there are many models that have been studied and the definition of which model is suitable for evaluation depends on the characteristics of the data associated with the analysis. Thus, this work aims to identify the most suitable model to predict the increase in leakage current in relation to the time the insulator is outdoors, exposed to environmental variations using the same database to compare the methods. In this paper, the models based on linear regression, support vector regression (SVR), multilayer Perceptron (MLP), deep neural network (DNN), and recurrent neural network (RNN) will be analyzed comparatively. The best accuracy results for prediction were found using the RNN models, resulting in an accuracy of up to 97.25%.


2020 ◽  
Vol 17 (170) ◽  
pp. 20200229
Author(s):  
Ruairí Donnelly ◽  
Christopher A. Gilligan

When increasing abundance of insect vectors is manifest across multiple fields of a crop at the landscape scale, the phenomenon is sometimes referred to as insect superabundance. The phenomenon may reflect environmental factors (i.e. environmentally mediated insect superabundance , EMiS), including climatic change. A number of pathogens, however, are also known to modify the quality of infected plants as a resource for their insect vectors. In this paper, we term increasing vector abundance when associated with pathogen modification of plants as pathogen-mediated insect superabundance (henceforth PMiS). We investigate PMiS using a new epidemiological framework. We formalize a definition of PMiS and indicate the epidemiological mechanism by which it is most likely to arise. This study is motivated by the occurrence of a particularly destructive cassava virus epidemic that has been associated with superabundant whitefly populations in sub-Saharan Africa. Our results have implications for how PMiS can be distinguished from EMiS in field data. Above all, they represent a timely foundation for further investigations into the association between insect superabundance and plant pathogens.


2018 ◽  
Vol 229 ◽  
pp. 04015
Author(s):  
Andy Sugianto

Application of Unmanned Aerial Vehicles (UAV) or drones to detect landslide Hazard and risk assessment becomes uncommon methodology in Indonesia. Nowadays, in Indonesia drones are still popular to use for commercial, news interest and advertisement purposes only. It is not mainly used for detecting landslide hazard or risk assessment purposes. Furthermore, the landslide in Indonesia is a common worldwide phenomenon that often occur and can have a great impact on the infrastructures and sometimes tragically result in fatalities. UAV provide a quick, safe, effective, and potentially superior means of inspecting large-scale, remote and difficult to access landforms with significant cost benefits compared to traditional inspection method by manual tracking. UAV can derive the aerial photography which represents actual condition and landslide hazard instantly. By using an aerial photograph, it can simplify the engineer to obtain viewpoint and presumption related with the mechanism of the landslide, some factors triggering the landslide (terrain and topography, drainage, river stream, logged area, slope height, structure, and community, etc). The result suggests that UAC can be one of most effective value in surveying and large-scale inspection to determine landslide hazard as well as general site condition.


2012 ◽  
Vol 214 (2) ◽  
pp. 121-131 ◽  
Author(s):  
A J Conley ◽  
R M Bernstein ◽  
A D Nguyen

Adrenarche is most commonly defined as a prepubertal increase in circulating adrenal androgens, dehydroepiandrosterone (DHEA) and its sulfo-conjugate (DHEAS). This event is thought to have evolved in humans and some great apes but not in Old World monkeys, perhaps to promote brain development. Whether adrenarche represents a shared, derived developmental event in humans and our closest relatives, adrenal androgen secretion (and its regulation) is of considerable clinical interest. Specifically, adrenal androgens play a significant role in the pathophysiology of polycystic ovarian disease and breast and prostate cancers. Understanding the development of androgen secretion by the human adrenal cortex and identifying a suitable model for its study are therefore of central importance for clinical and evolutionary concerns. This review will examine the evidence for adrenarche in nonhuman primates (NHP) and suggest that a broader definition of this developmental event is needed, including morphological, biochemical, and endocrine criteria. Using such a definition, evidence from recent studies suggests that adrenarche evolved in Old World primates but spans a relatively brief period early in development compared with humans and some great apes. This emphasizes the need for frequent longitudinal sampling in evaluating developmental changes in adrenal androgen secretion as well as the tenuous nature of existing evidence of adrenarche in some species among the great apes. Central to an understanding of the regulation of adrenal androgen production in humans is the recognition of the complex nature of adrenarche and the need for more carefully conducted comparative studies and a broader definition in order to promote investigation among NHP in particular.


2004 ◽  
Vol 4 (1) ◽  
pp. 133-146 ◽  
Author(s):  
J. L. Zêzere ◽  
E. Reis ◽  
R. Garcia ◽  
S. Oliveira ◽  
M. L. Rodrigues ◽  
...  

Abstract. A general methodology for the probabilistic evaluation of landslide hazard is applied, taking in account both the landslide susceptibility and the instability triggering factors, mainly rainfall. The method is applied in the Fanhões-Trancão test site (north of Lisbon, Portugal) where 100 shallow translational slides were mapped and integrated into a GIS database. For the landslide susceptibility assessment it is assumed that future landslides can be predicted by statistical relationships between past landslides and the spatial data set of the predisposing factors (slope angle, slope aspect, transversal slope profile, lithology, superficial deposits, geomorphology, and land use). Susceptibility is evaluated using algorithms based on statistical/probabilistic analysis (Bayesian model) over unique-condition terrain units in a raster basis. The landslide susceptibility map is prepared by sorting all pixels according to the pixel susceptibility value in descending order. In order to validate the results of the susceptibility ana- lysis, the landslide data set is divided in two parts, using a temporal criterion. The first subset is used for obtaining a prediction image and the second subset is compared with the prediction results for validation. The obtained prediction-rate curve is used for the quantitative interpretation of the initial susceptibility map. Landslides in the study area are triggered by rainfall. The integration of triggering information in hazard assessment includes (i) the definition of thresholds of rainfall (quantity-duration) responsible for past landslide events; (ii) the calculation of the relevant return periods; (iii) the assumption that the same rainfall patterns (quantity/duration) which produced slope instability in the past will produce the same effects in the future (i.e. same types of landslides and same total affected area). The landslide hazard is present as the probability of each pixel to be affected by a slope movement, and results from the coupling between the susceptibility map, the prediction-rate curve, and the return periods of critical rainfall events, on a scenario basis. Using this methodology, different hazard scenarios were assessed, corresponding to different rain paths with different return periods.


Author(s):  
Isra Haryati Diva ◽  
Usqo Irwanto ◽  
Khairul Nizam ◽  
Latifa Annur ◽  
Dhanu Sekarjati ◽  
...  

The survey geomorphology, it is the one apart of applied geomorphology. In case has done investigation character of geomorphological landscape of Mount Talang and mapping of landslide hazard potential. In this research has used some method, the first field observation and sampling for geomorphology character study were conducted. Second the mapping landslide hazard used method the MAFF Japan where integrating physical field data and spatial data using geographic information system. The results of this study where found some volcanic morphology, volcanic cones, upper slopes, middle slope, lower slopes, foot slope, and volcanic plain. The landslide hazard, where involving sources of observation and sampling for the study of geomorphological characters. From the research has found the landslide hazard in four zone, zone (I) land stable and low hazard potential large 9 ha, zone (II) land enough stable and middle hazard potential large 12.295 ha, zone (III) land less stable and high hazard potential large 1.118 ha, and Zone (IV) land unstable and highest hazard potential 0.1 ha. The typical of geomorphology, morphometry, and land use it has really influence to landslide potential to landslide hazard.


2006 ◽  
Vol 34 ◽  
pp. 63-72
Author(s):  
A. Strouth ◽  
E. Eberhardt ◽  
O. Hungr

A "Total Slope Analysis" methodology, that combines several numerical techniques, is adopted to investigate an unstable rock slope in Washington State, USA. For this specific study, the distinct-element code UDEC is used to assess the stability and potential failure volume of the rockslide. Once the potential rockslide volume has been estimated and failure mechanism assessed, the runout path, distance and velocity are assessed using the dynamic or rheological flow model DAN3D. Site investigation and data reconnaissance plays an important role for both stages in the "Total Slope Analysis", including outcrop mapping, aerial photograph interpretation, scanline joint surveys and 3-D laser scanning. The results of the "Total Slope Analysis" can be directly applied to assessment and mitigation of the landslide hazard, greatly aiding engineering judgment by providing key qualitative and quantitative insights into the risk analysis.


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