scholarly journals A MULTIDISCIPLINARY LANDSLIDE CASE STUDY: DEVREK LANDSLIDE

2018 ◽  
Vol XLII-3/W4 ◽  
pp. 227-230
Author(s):  
K. S. Gormus ◽  
S. H. Kutoglu ◽  
G. Gurbuz ◽  
O. F. Capar ◽  
V. Akgul
Keyword(s):  
Laser Scanning ◽  
Action Plan ◽  
Mass Movement ◽  
Northern Region ◽  
Angle Of Repose ◽  
Mass Movements ◽  
Landslide Occurrence ◽  
Aerial Photogrammetry ◽  
Active Landslide

<p><strong>Abstract.</strong> Landslides are one of the leading causes of loss of life and property in the World. Landslides are the most profound ones within other mass movements. Especially in the Northern region of Turkey is severely threatened by landslides. Mass movements can be divided several main classes which are falls, slides, creeps, flows and complex movements. Landslides can occur due to a variety of reasons and most basic one of them is the angle of repose or slope of the hillside. If the angle is overly steep, gravity will pull the material downward, causing a mass movement. Many studies have been carried out in Turkey to monitor landslides, prevent and reduce landslides damage. These studies mostly focused on forecasting of landslides and damage determination after landslides. Activities required to be carried out in the field can be resulted with unwanted consequences for work safety while the landslide is still active. A landslide is triggered at Devrek, Zonguldak on July 16th, 2015 which affected an area of 40 hectares. For this reason, 88 buildings and a school are evacuated by authorities. To support emergency action plan while ongoing active landslide occurrence at Devrek, apart from the geotechnical approach, aerial photogrammetry, terrestrial laser scanning, land-based SAR methods are used. This study is a summary of studies carried out simultaneously with an active landslide at Devrek, Zonguldak on July 20th &amp;ndash; August 8th, 2015.</p>

scholarly journals GEOSPATIAL MODEL FOR LARGE SCALE SEA CLIFF ROCKFALL SUSCEPTIBILITY MAPPING

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 341-347
Author(s):  
P. Redweik ◽  
R. Matildes ◽  
F. Marques
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Mass Movement ◽  
Susceptibility Map ◽  
Mass Movements ◽  
Aerial Photogrammetry ◽  
The Status ◽  
Logistic Regression Method ◽  
Definition Of ◽  
Gis Software

<p><strong>Abstract.</strong> Due to their relevance to the environment and economy, coastal areas are considered national strategic segments that should be preserved. Since erosion phenomena occur intensively in those areas, it is capital to monitor them in order to identify risk zones. In addition to national and regional studies, it is also necessary to conduct local monitoring of erosion prone areas, especially those which are often frequented by people, such as beaches limited by high cliffs. Large scale vertical mapping is necessary to model their susceptibility to mass movements, in order to provide adequate prevention, protection and assistance.</p> <p>Recent techniques like laser scanning or aerial photogrammetry using UAVs allow the definition of the status quo of a cliff wall and its situation a few years back. But to assess the susceptibility to rock mass movements in such cliff segments, inventories of past events are of primordial importance. These inventories allow applying several statistic models to better understand susceptibility together with a set of variables of internal and external nature regarding the cliff site.</p> <p>We present a case study focused on the beach of Ribeira d’Ilhas (Mafra, Portugal), where a workflow of terrestrial photogrammetry for present day situation and recovery of old analogue stereoscopic pairs (1999, 2000, 2003) was implemented. A mass movement inventory (1999-2014) was compiled by multitemporal comparison followed by a detailed characterization of the cliff using a GIS software. Finally, the application of the logistic regression method allowed the definition of a susceptibility map of the cliff wall towards the occurrence of mass movements.</p>

scholarly journals Rockfall monitoring by Terrestrial Laser Scanning – case study of the basaltic rock face at Castellfollit de la Roca (Catalonia, Spain)

2011 ◽  
Vol 11 (3) ◽  
pp. 829-841 ◽  
Author(s):  
A. Abellán ◽  
J. M. Vilaplana ◽  
J. Calvet ◽  
D. García-Sellés ◽  
E. Asensio
Keyword(s):  
Urban Areas ◽  
Laser Scanning ◽  
Mass Movement ◽  
Laser Scanner ◽  
Point Clouds ◽  
Basaltic Rock ◽  
Historical Record ◽  
Rock Face ◽  
The Village

Abstract. This case study deals with a rock face monitoring in urban areas using a Terrestrial Laser Scanner. The pilot study area is an almost vertical, fifty meter high cliff, on top of which the village of Castellfollit de la Roca is located. Rockfall activity is currently causing a retreat of the rock face, which may endanger the houses located at its edge. TLS datasets consist of high density 3-D point clouds acquired from five stations, nine times in a time span of 22 months (from March 2006 to January 2008). The change detection, i.e. rockfalls, was performed through a sequential comparison of datasets. Two types of mass movement were detected in the monitoring period: (a) detachment of single basaltic columns, with magnitudes below 1.5 m3 and (b) detachment of groups of columns, with magnitudes of 1.5 to 150 m3. Furthermore, the historical record revealed (c) the occurrence of slab failures with magnitudes higher than 150 m3. Displacements of a likely slab failure were measured, suggesting an apparent stationary stage. Even failures are clearly episodic, our results, together with the study of the historical record, enabled us to estimate a mean detachment of material from 46 to 91.5 m3 year−1. The application of TLS considerably improved our understanding of rockfall phenomena in the study area.

scholarly journals A multi-range approach for Cultural Heritage survey: a case study in Mantua Unesco site

2014 ◽  
Vol XL-5 ◽  
pp. 157-164 ◽  
Author(s):  
S. Chiarini ◽  
S. Cremonesi ◽  
L. Fregonese ◽  
F. Fassi ◽  
L. Taffurelli
Keyword(s):  
Comparative Analysis ◽  
Cultural Heritage ◽  
Point Cloud ◽  
Laser Scanning ◽  
General Survey ◽  
Aerial Photogrammetry ◽  
Active Sensor ◽  
Cloud Models ◽  
Unesco Site

In this paper, a Cultural Heritage survey, performed by employing and integrating different type of acquisition technologies (imagebased and active sensor based) is presented. The aim of the survey is to create a 3D multiscale database, therefore, different restitution scales, from the architectural-urban one to a detail one are taken in consideration. This research is part of a project financed by the Unesco for the study of historical gardens located in Mantua and Sabbioneta, and in particular for the <i>Palazzo Te</i> renaissance gardens in Mantua, which are reported in this paper. First of all, a general survey of the area has been realized by employing the classical aerial photogrammetry in order to provide the actual arboreal and urban furniture conditions of the gardens (1:500 scale). Next, a detailed photogrammetric survey of the Esedra courtyard in <i>Palazzo Te</i> has been performed by using a UAV system. At the end, laser scanning and traditional topography have been used for the terrestrial detailed acquisition of gardens and architectural façades (1:50&ndash;1:20 scale). The aim of this research is to create a suitable graphical documentation support for the study of the structure of the gardens, to analyze how they have been modified over the years and as an effective support for eventual future re-design. Moreover, the research has involved a certain number of botanic and archeological investigations, which have been duly acquired and modeled with image based systems.<br><br> Starting from the acquired datasets with their acquisition scales, a series of comparative analysis have been performed, especially for those areas in which all the systems have been employed. The comparisons have been extracted by analyzing point cloud models obtained by using a topographical network.<br><br> As a result, the multi-range approach efficiency, obtained by employing the actual available technologies have been illustrated in the present work.

Dealing with uncertainties in assessing geomorphic change. Spatially estimating structure-from-motion precisions using a block-resampling approach.

2021 ◽  
Author(s):  
Florian Strohmaier ◽  
Jason Goetz ◽  
Sam McColl
Keyword(s):  
Change Detection ◽  
Structure From Motion ◽  
Laser Scanning ◽  
Mass Movement ◽  
Grid Cell ◽  
Time Frame ◽  
Reconstruction Algorithms ◽  
Erosion And Deposition ◽  
Uncertainty Estimates

&lt;p&gt;Structure-from-Motion &amp;#8211; Multi-View Stereo (SfM-MVS) has become a widely used approach in the study of Earth surface processes to reconstruct high-resolution topography (HRT) models. Starting in the early 2010s, it has become a cheap, flexible and user-friendly alternative to aerial/terrestrial laser scanning in geosciences and in change detection analyses in particular. In this context, previous work has dealt with the spatial distribution of error and with appropriately accounting for uncertainty estimates of such models in change detection results. However, error distribution and propagation are still not widely accounted for in standard analyses: Various sources of error result in complex distribution of model precision and accuracy. This poses challenges on study effort and complexity.&lt;/p&gt;&lt;p&gt;In this study, we developed a novel approach for obtaining spatially distributed estimates of precision for SfM-MVS derived digital elevation models (DEM). We applied block resampling to simulate repeatedly surveyed flights. This approach allows us to create multiple independently-resampled image sets that capture the general geometry of the original survey for SfM-MVS reconstruction. In a case study of observing erosion and deposition patterns of a highly active badass gully (Mangatu fluvio&amp;#8211;mass movement gully complex, East Coast, NZ) we simulated 20 repeated flights (i.e. images sets) for images acquired from UAVs in 2018 and 2019. The subsequent precisions were used for deriving confidence intervals for sediment budgets. Overall, the precision estimates in open-terrain matched well with previous studies based on repeated surveys (~ &lt;5cm). Weaker precisions were observed in areas of vegetation or where viewing angles could be obstructed by surrounding vegetation. The simulated DEMs, which were based on the mean value for each grid cell across the simulations, were in good agreement with the original reconstructed scene: differences were mainly less than 2 cm for most of the exposed erosion and deposition areas.&lt;/p&gt;&lt;p&gt;We estimated volumetric net change to be within [&amp;#8211; 113.07;&amp;#8211;101.48]&amp;#215;1000m&amp;#179; with 95% confidence between April 2018 and April 2019. Gross sediment erosion was [&amp;#8211;123.07;&amp;#8211;111.73]&amp;#215;1000m&amp;#179;; gross deposition was [8.9;11.7]&amp;#215;1000m&amp;#179; in the same time frame. This is well within findings of previous studies. However, compared to these, we could substantially improve the precision of uncertainty estimates. While computationally intensive, our method is able to reduce field work compared to similar studies. It additionally has the advantage of computing precisions that account for uncertainties in both SfM and MVS reconstruction algorithms. This means that SfM-MVS precisions can be computed on past surveys given the images were taken with sufficient overlap, as we demonstrated in our case study.&lt;/p&gt;

scholarly journals The Suitability of UAS for Mass Movement Monitoring Caused by Torrential Rainfall—A Study on the Talus Cones in the Alpine Terrain in High Tatras, Slovakia

2019 ◽  
Vol 8 (8) ◽  
pp. 317 ◽  
Author(s):  
Rudolf Urban ◽  
Martin Štroner ◽  
Peter Blistan ◽  
Ľudovít Kovanič ◽  
Matej Patera ◽  
...  
Keyword(s):  
National Parks ◽  
Laser Scanning ◽  
Morphological Changes ◽  
Mass Movement ◽  
Individual Measurement ◽  
Aerial Photogrammetry ◽  
Hiking Trails ◽  
Torrential Rainfall ◽  
The Difference ◽  
The Individual

The prediction of landslides and other events associated with slope movement is a very serious issue in many national parks around the world. This article deals with the territory of the Malá Studená Dolina (Little Cold Valley, High Tatras National Park—Slovakia), where there are extensive talus cones, through which seasonally heavy hiking trails lead. In the last few years particularly, there have been frequent falls and landslides in the mountainous environment, which also caused several fatal injuries in 2018. For the above reasons, efforts are being made to develop a methodology for monitoring the changes of the talus cones in this specific alpine area, to determine the size, speed, and character of the morphological changes of the soil. Non-contact methods of mass data collection (laser scanning with Leica P40 and aerial photogrammetry with unmanned aerial system (UAS) DJI Phantom 4 Pro) have been used. The results of these measurements were compared and the overall suitability of both methods for measurement in such terrain evaluated. The standard deviation of the difference of surface determination (represented by the point cloud) is about 0.03 m. As such accuracy is sufficient for the purpose of monitoring talus cones and the use of UAS is easier and associated with lower risk of damage of expensive equipment, we conclude that this method is more suitable for mapping and for repeated monitoring of such terrain. The properties of the outputs of the individual measurement methods, the degree of measurement difficulty and specific measurement conditions in the mountainous terrain, as well as the economy of the individual methods, are discussed in detail.

scholarly journals Development of the fishing and commercialization of the blue crabs in Bizerta and Ghar EL Melh lagoons: A case study of promotion opportunities of blue growth in Tunisia

2021 ◽  
Vol 10 (2) ◽  
pp. 66-74
Author(s):  
Sami Mili
Keyword(s):  
Blue Crab ◽  
Action Plan ◽  
Northern Region ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Blue Growth ◽  
The Government ◽  
First Time ◽  
New Jobs

The blue crab, a species of crustaceans which originally came from the Red Sea through the Suez Canal, appeared, for the first time, in Tunisian waters in the cities of Skhira (governorate of Sfax) and Ghannouch (governorate of Gabes), at the end of 2014. After a year, this species adapted to the environment and proliferated throughout the Gulf of Gabes, to subsequently appear in the Gulf of Hammamet in 2016.In 2018, this invasive species emerged in the lagoons of Bizerte and Ghar EL-Melh. Coastal fishermen operating in crab-colonized areas have reported many problems associated with the appearance of this species in fisheries, including degradation of fishing nets, alteration of other caught species, time spent in its disentanglement, and the drop in stocks of many fish species of high commercial value in the invaded areas. In view of these issues, the government has drawn up and funded a national plan to promote crab fishing, development and marketing in the Gulf of Gabes. Faced with the weakness of internal demand, the orientation towards the export of crab stands out as a pertinent alternative to explore. Our project aims to develop an action plan in order to enhance the marketing of the blue crab on a national and international scale in the northern region of Tunisia, precisely in the lagoons of Bizerte and Ghar El Melh. The creation of new jobs and the improvement of incomes for the vulnerable populations of the two communes of MenzelAbderrahmen and Ghar El Melh are the main expected results of this project.

Rethinking the Agency of Women in the Shea Industry

Politeia ◽  
2018 ◽  
Vol 37 (1) ◽  
Author(s):  
Abiba Yayah
Keyword(s):  
Rural Women ◽  
Field Work ◽  
Northern Region ◽  
African Countries ◽  
Good Source ◽  
Everyday Practices ◽  
Home Based

The agency of women in most African countries is often affected by the socio-economic and political policies that are almost always disadvantageous to women, especially women who have little to no knowledge of their rights. Using the shea industry in Ghana as a case study, I chronicle the challenges as recounted by rural women involved in this home-based work in the Northern Region of Ghana and critically analyse these challenges and their implications. Focusing mainly on the results of my recent field work, I present some of the accounts relating to the lack and exclusion of recognition of and respect for the experiences of rural women who are in fact the linchpin of the shea industry in Ghana. Initiatives and strategies of non-governmental organisations and some governmental policies have attempted to address these challenges that have implications for the livelihoods of rural women. Research and policies have only offered “band-aid solutions” to the economic disempowerment of rural women in the shea industry in Ghana as they have not dealt with the causes. This article seeks to refute the claim that equity exists by indicating the lack of equity and justice in the policies in the shea industry. In an attempt to provide an understanding of the economic disempowerment of women in this industry, I consider my field work as a good source as it exposes the experiences and everyday practices as narrated by rural women in the industry. This article seeks to analyse the existing discourses especially those pertaining to the contributions and experiences of rural women in the shea industry.

Si Crans-Montana meurt. Soigner le corps malade d’une station

ARCHALP ◽  
2020 ◽  
Vol 2020 (N. 4 / 2020) ◽  
Author(s):  
Patrick Giromini
Keyword(s):  
Social Context ◽  
Alpine Meadow ◽  
Action Plan ◽  
Geographic Location ◽  
Built Heritage ◽  
Environment And Health ◽  
Health Action ◽  
The Relationship ◽  
Health Action Plan

New Alpine companies, like Crans-Montana on the Haut-Plateau, remain, more often than not, trapped in representative logic opposing the clan of modernists to that of defenders of values anchored in an ideal-typical tradition. The Haut-Plateau territory, so named due to its geographic location and topographic conformation – not for the morphology of the soil – was still a space free of any construction in the mid-nineteenth century. This vast alpine meadow was marked by a few utility buildings for sheltering cattle and hay during the intermediate seasons that precede the full summer. At the turn of the 3rd millennium, the built heritage, essentially consisting of hotel structures and holiday residences, is no longer able to welcome the new socio-economic dynamics linked to the mono-culture of skiing. This crisis calls habits, both old and new, into question, given the youth of the tourist resort. In June 2000, a Federal programme selected Crans-Montana as a case study for testing an Environment and Health Action Plan. This provided an opportunity for a group of architects to formulate an inter-municipal blueprint that activated a series of urban renewal projects. The new architectural formulae that emerge try to go beyond stylistic modernism by reinterpreting the relationship with the built environment and its social context.

Low Temperature Fault Isolation Using Soft Defect Localization

2012 ◽  
Author(s):  
Kristopher D. Staller
Keyword(s):  
Low Temperatures ◽  
Laser Scanning ◽  
Low Cost ◽  
Fault Isolation ◽  
Laser Scanning Microscopy ◽  
Cold Temperature ◽  
Multiple Point ◽  
Defect Localization ◽  
Low Levels

Abstract Cold temperature failures are often difficult to resolve, especially those at extreme low levels (&lt; -40°C). Momentary application of chill spray can confirm the failure mode, but is impractical during photoemission microscopy (PEM), laser scanning microscopy (LSM), and multiple point microprobing. This paper will examine relatively low-cost cold temperature systems that can hold samples at steady state extreme low temperatures and describe a case study where a cold temperature stage was combined with LSM soft defect localization (SDL) to rapidly identify the cause of a complex cold temperature failure mechanism.

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