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 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 The door behind the bamboo curtain - Chinese law and policy on refugee status

2021 ◽  
Author(s):  
◽  
Lili Song
Keyword(s):  
Large Scale ◽  
Chinese Government ◽  
Policy And Practice ◽  
Refugee Status ◽  
Chinese Law ◽  
Legal Provisions ◽  
Law And Policy ◽  
High Commissioner ◽  
The Status ◽  
Definition Of

<p>This thesis systematically considers the law and policy on refugee status in the People’s Republic of China. It considers relevant Chinese legal provisions, applicable bilateral and multinational treaties, as well as China’s refugee policy and practice. It also presents and analyses first-hand information collected through interviews with refugees and aid workers.  China is an emerging destination of refugees and other displaced foreigners. Although China is a party to the 1951 Convention relating to the Status of Refugees and its 1967 Protocol, Chinese law contains no provisions governing the definition of a refugee or the determination of refugee status. Further, there is a gap between the criteria for asylum in the 1982 Chinese Constitution and the criteria for refugee status in the 1951 Convention.  In practice, although the Chinese government has generally allowed the United Nations High Commissioner for Refugees to process individual applications for refugee status, the Chinese government has practically performed the function of refugee status determination in large-scale influx situations through policy decisions. In these situations, the security, political, and strategic interests of China have often overshadowed China’s commitment under the 1951 Convention.  China has been cautious about recognising refugees on its territory. However, the Chinese government has clearly demonstrated a growing interest in addressing the issue of refugee recognition within a more formalised framework.  In conclusion, this thesis recommends that China adopt a legal refugee definition in line with the 1951 Convention relating to the Status of Refugees and develop a predictable and fair national RSD mechanism.</p>

scholarly journals The door behind the bamboo curtain - Chinese law and policy on refugee status

2021 ◽  
Author(s):  
◽  
Lili Song
Keyword(s):  
Large Scale ◽  
Chinese Government ◽  
Policy And Practice ◽  
Refugee Status ◽  
Chinese Law ◽  
Legal Provisions ◽  
Law And Policy ◽  
High Commissioner ◽  
The Status ◽  
Definition Of

<p>This thesis systematically considers the law and policy on refugee status in the People’s Republic of China. It considers relevant Chinese legal provisions, applicable bilateral and multinational treaties, as well as China’s refugee policy and practice. It also presents and analyses first-hand information collected through interviews with refugees and aid workers.  China is an emerging destination of refugees and other displaced foreigners. Although China is a party to the 1951 Convention relating to the Status of Refugees and its 1967 Protocol, Chinese law contains no provisions governing the definition of a refugee or the determination of refugee status. Further, there is a gap between the criteria for asylum in the 1982 Chinese Constitution and the criteria for refugee status in the 1951 Convention.  In practice, although the Chinese government has generally allowed the United Nations High Commissioner for Refugees to process individual applications for refugee status, the Chinese government has practically performed the function of refugee status determination in large-scale influx situations through policy decisions. In these situations, the security, political, and strategic interests of China have often overshadowed China’s commitment under the 1951 Convention.  China has been cautious about recognising refugees on its territory. However, the Chinese government has clearly demonstrated a growing interest in addressing the issue of refugee recognition within a more formalised framework.  In conclusion, this thesis recommends that China adopt a legal refugee definition in line with the 1951 Convention relating to the Status of Refugees and develop a predictable and fair national RSD mechanism.</p>

The effect of forest fire on mass movement in Lebanese mountainous areas

2014 ◽  
Vol 23 (6) ◽  
pp. 845
Author(s):  
Rouba Ziadé ◽  
Chadi Abdallah ◽  
Nicolas Baghdadi
Keyword(s):  
Forest Fire ◽  
Satellite Images ◽  
Mass Movement ◽  
Potential Effect ◽  
Burn Severity ◽  
Susceptibility Map ◽  
Mass Movements ◽  
Mountainous Areas ◽  
Effect Factors ◽  
Landsat Images

Mass movements are major hazards that threaten natural and human environments. In Lebanon, the occurrence of mass movements increased by almost 60% between 1956 and 2008. Forest fire has emerged as an additional hazard: it destroyed over 25% of Lebanon’s forests in a period less than 40 years. This paper investigates the potential effect of forest fire on the occurrence of mass movements in the Damour and Nahr Ibrahim watersheds of Lebanon. Mass movement and forest fire inventory maps were produced through remote sensing using aerial and satellite images. Forest fire was included as an additional factor in mass movement induction, and its effect was quantified from Landsat images through the normalised burn ratio (NBR) index. A field study was conducted to substantiate the mass movement inventory and NBR maps. Following the standardisation of the effect factors into layers using geographic information systems, the weight factor of each layer for inducing mass movements was evaluated using the modified InfoVal method, and a mass movement susceptibility map was generated. Exceeded only by changes in land cover, the NBR produced the highest weights, making forest fire burn severity the second highest factor influencing mass movement occurrence in the study areas.

scholarly journals Combining Sentinel-1 Interferometry and Ground-Based Geomatics Techniques for Monitoring Buildings Affected by Mass Movements

2021 ◽  
Vol 13 (3) ◽  
pp. 452
Author(s):  
Xue Chen ◽  
Vladimiro Achilli ◽  
Massimo Fabris ◽  
Andrea Menin ◽  
Michele Monego ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Ground Deformation ◽  
Satellite System ◽  
Mass Movements ◽  
The North ◽  
Geological Processes ◽  
Multi Temporal ◽  
Image Pixels ◽  
Global Navigation Satellite

Mass movements represent a serious threat to the stability of human structures and infrastructures, and cause loss of lives and severe damages to human properties every year worldwide. Built structures located on potentially unstable slopes are susceptible to deformations due to the displacement of the ground that at worst can lead to total destruction. Synthetic aperture radar (SAR) data acquired by Sentinel-1 satellites and processed by multi-temporal interferometric SAR (MT-InSAR) techniques can measure centimeter to millimeter-level displacement with weekly to monthly updates, characterizing long-term large-scale behavior of the buildings and slopes. However, the spatial resolution and short wavelength weaken the performance of Sentinel-1 in recognizing features (i.e., single buildings) inside image pixels and maintaining the coherence in mountainous vegetated areas. We have proposed and applied a methodology that combines Sentinel-1 interferometry with ground-based geomatics techniques, i.e., global navigation satellite system (GNSS), terrestrial laser scanning (TLS) and terrestrial structure from motion photogrammetry (SfM), for fully assessing building deformations on a slope located in the north-eastern Italian pre-Alps. GNSS allows verifying the ground deformation estimated by MT-InSAR and provides a reference system for the TLS and SfM measurements, while TLS and SfM allow the behavior of buildings located in the investigated slope to be monitored in great detail. The obtained results show that damaged buildings are located in the most unstable sectors of the slope, but there is no direct relationship between the rate of ground deformation of these sectors and the temporal evolution of damages to a single building, indicating that mass movements cause the displacement of blocks of buildings and each of them reacts differently according to its structural properties. This work shows the capability of MT-InSAR, GNSS, TLS and SfM in monitoring both buildings and geological processes that affect their stability, which plays a key role in geohazard analysis and assessment.

scholarly journals AVALIAÇÃO DA SUSCEPTIBILIDADE À EROSÃO E AOS MOVIMENTOS DE MASSA NO MUNICÍPIO DE IBIRITÉ

2014 ◽  
Author(s):  
Patrícia Mara Lage Simões ◽  
Cristiane Valéria Oliveira
Keyword(s):  
Mass Movement ◽  
Morphological Characteristics ◽  
Environmental Problems ◽  
Human Action ◽  
Mass Movements ◽  
Factors Affecting ◽  
Conditioning Factors ◽  
Inappropriate Use ◽  
Definition Of ◽  
The City

O processo de urbanização e as alterações do meio físico decorrentes do uso do solo constituem um fator gerador de problemasambientais. A concentração populacional aliada à falta de um planejamento de ocupação tem motivado o uso inadequado do espaçourbano, provocando a ocorrência de sérios desequilíbrios ambientais. Esses desequilíbrios quando ocorrem em áreas com característicasfísicas impróprias à ocupação, como aquelas cujas condições ambientais, resultantes da combinação de fatores geológicos,geomorfológicos, pedológicos e topográficos, dentre outros, favorecem a ocorrência de processos erosivos e movimentos de massa. Estetrabalho tem como objetivo avaliar os fatores que interferem na definição da susceptibilidade a erosão e movimentos de massa nomunicípio de Ibirité/MG. Foram analisados os seguintes fatores condicionantes: características geológicas, morfologia; e também os fatoresdeflagradores provocados pela ação antrópica. Por meio dessa análise foi produzido um mapa identificando as áreas de maior e menorsusceptibilidade á erosão e movimentos de massa. O município apresenta a maior parte de seu terreno com moderada susceptibilidade,sendo assim, o uso do solo deve ser planejado para que a ocupação seja adequada de forma a minimizar o risco de ocorrência de processoserosivos e movimento de massa. O poder público deve fiscalizar essa ocupação, verificando se existe a presença da infra-estruturanecessária nos loteamentos.Palavras-chave: SUSCEPTIBILIDADE A EROSÃO, MOVIMENTO DE MASSA, PROBLEMAS AMBIENTAIS ABSTRACTEVALUATION OF SUSCEPTIBILITY TO EROSION AND MASS MOVEMENTS IN THE MUNICIPALITY OF IBIRITE. The process ofurbanization and changes in the physical environment resulting from land use are a key driver of environmental problems. The populationdensity and lack of planning occupancy has motivated the inappropriate use of urban land, causing the occurrence of seriousenvironmental problems. These problem when occur in areas with physical characteristics inappropriate for occupation, as those whoseenvironmental conditions come from the combination of geological, geomorphological, pedological and topographical factors, amongothers, favor the occurrence of erosion and mass movements . This study aims to assess the factors affecting the definition of susceptibilityto erosion and mass movements in the municipality Ibirité / MG. The following conditioning factors were analyzed: geological,morphological characteristics; and also the trigger factors caused by human action. Through this analysis was produced a map identifyingareas of high and low susceptibility to erosion and mass movements. The city has most of its terrain with moderate susceptibility, thus theland use should be planned so that the occupation need to be adequate to minimize the risk of erosion and mass movement. Thegovernment should monitor this occupation, checking if there is presence of the necessary infrastructure.Keywords: SUSCEPTIBILITY THE EROSION, MASS MOVEMENTS, ENVIRONMENTAL PROBLEMS

scholarly journals Spatiotemporal Large-Scale Networks Shaped by Air Mass Movements

2021 ◽  
Vol 6 ◽  
Author(s):  
M. Choufany ◽  
D. Martinetti ◽  
R. Senoussi ◽  
C. E. Morris ◽  
S. Soubeyrand
Keyword(s):  
Large Scale ◽  
Seasonal Pattern ◽  
Geographical Area ◽  
Three Dimensional ◽  
Mass Movements ◽  
Air Mass ◽  
Air Masses ◽  
Large Scale Networks ◽  
Definition Of ◽  
French Region

The movement of atmospheric air masses can be seen as a continuous flow of gases and particles hovering over our planet, and it can be locally simplified by means of three-dimensional trajectories. These trajectories can hence be seen as a way of connecting distant areas of the globe during a given period of time. In this paper we present a mathematical formalism to construct spatial and spatiotemporal networks where the nodes represent the subsets of a partition of a geographical area and the links between them are inferred from sampled trajectories of air masses passing over and across them. We propose different estimators of the intensity of the links, relying on different bio-physical hypotheses and covering adjustable time periods. This construction leads to a new definition of spatiotemporal networks characterized by adjacency matrices giving, e.g., the probability of connection between distant areas during a chosen period of time. We applied our methodology to characterize tropospheric connectivity in two real geographical contexts: the watersheds of the French region Provence-Alpes-Côte d’Azur and the coastline of the Mediterranean Sea. The analysis of the constructed networks allowed identifying a marked seasonal pattern in air mass movements in the two study areas. If our methodology is applied to samples of air-mass trajectories, with potential implications in aerobiology and plant epidemiology, it could be applied to other types of trajectories, such as animal trajectories, to characterize connectivity between different components of the landscape hosting the animals.

scholarly journals LINE SEGMENTATION OF 2D LASER SCANNER POINT CLOUDS FOR INDOOR SLAM BASED ON A RANGE OF RESIDUALS

2017 ◽  
Vol IV-2/W4 ◽  
pp. 363-369 ◽  
Author(s):  
M. Peter ◽  
S. R. U. N. Jafri ◽  
G. Vosselman
Keyword(s):  
Laser Scanning ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Laser Scanner ◽  
Point Clouds ◽  
Indoor Environments ◽  
Six Degrees Of Freedom ◽  
Localization And Mapping ◽  
Feature Based ◽  
Definition Of

Indoor mobile laser scanning (IMLS) based on the Simultaneous Localization and Mapping (SLAM) principle proves to be the preferred method to acquire data of indoor environments at a large scale. In previous work, we proposed a backpack IMLS system containing three 2D laser scanners and an according SLAM approach. The feature-based SLAM approach solves all six degrees of freedom simultaneously and builds on the association of lines to planes. Because of the iterative character of the SLAM process, the quality and reliability of the segmentation of linear segments in the scanlines plays a crucial role in the quality of the derived poses and consequently the point clouds. The orientations of the lines resulting from the segmentation can be influenced negatively by narrow objects which are nearly coplanar with walls (like e.g. doors) which will cause the line to be tilted if those objects are not detected as separate segments. State-of-the-art methods from the robotics domain like Iterative End Point Fit and Line Tracking were found to not handle such situations well. Thus, we describe a novel segmentation method based on the comparison of a range of residuals to a range of thresholds. For the definition of the thresholds we employ the fact that the expected value for the average of residuals of <i>n</i> points with respect to the line is <i>σ</i>&amp;thinsp;/&amp;thinsp;&amp;radic;<i>n</i>. Our method, as shown by the experiments and the comparison to other methods, is able to deliver more accurate results than the two approaches it was tested against.

Groundwater-induced Seasonal Slumps in Gullies of the Bação Complex, Southeastern Brazil

2021 ◽  
Author(s):  
Yesser Marin Rodriguez Hernandez ◽  
Luis de Almeida Prado BACELLAR ◽  
Jefferson Alves Araujo Junior
Keyword(s):  
Rainy Season ◽  
Large Scale ◽  
Agricultural Land ◽  
Unsaturated Flow ◽  
Low Cost ◽  
Limit Equilibrium ◽  
Mass Movement ◽  
Dry Season ◽  
Southeastern Brazil ◽  
Mass Movements

Abstract Areas with a high density of large-scale gullies are frequent in regions of the crystalline basement of southeastern Brazil, such as the Bação Complex. These gullies pose a high risk for people and properties, and cause loss of agricultural land, silting up and flow reduction of waterways, among other impacts. Gullies originating as erosion by channelized surface runoff can be controlled relatively easily by ordinary containment practices. However, when erosive channels reach the groundwater, erosive processes conditioned by subsurface flows start acting, causing mass movements and their control becomes more difficult. Continuous field monitoring shows that these mass movements occur not only in the rainy season, as expected, but also in the dry season. To understand the dynamics of mass movement in the evolution of these features, a representative unstable gully in the Bação Complex was selected. As it is common in this region, this gully presents very steep and unstable slopes, especially due to slumps. Numerical simulations of saturated and unsaturated flow have shown that, in this region of high seasonality, the aquifer is recharged in two stages. Safety factor analysis by limit-equilibrium method indicates that slumps occur during the rainy season, when the aquifer at the toe of the slope is recharged, and in the dry season, when the upper slope is recharged after a few months' lags due to thicker unsaturated zone having slower water flow. Finally, a low-cost stabilization method was proposed involving the construction of alternative drains and retention walls.

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.

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