Landslide Hazard mapping

In Indonesia, landslides become a disaster that has the most lead a victim. Nationally, during 2016 occurred 575 landslides that happened and 177 peoples died because of landslides. One of area that potential landslide is Kulonprogo which a steep hill-steep slopes. This study intend to monitoring and mapping disaster areas, which then created a vulnerability zonation map and modeling visualization landslide impact that may occur in the research area. The method used by integrating remote sensing and field data are combined with GIS. Object-based image analysis airphotos ,combined with LANDSAT and Google Earth show a progress infrastructure and settlement development in research area included some landslides that occur at the same point in the form of arc landslide and sliding. The field data show that the slope of study area has a rather steep to very steep slope from 38°-85°, composed of litology andesite lava, volcanic breccia, and coral limestone. Characteristics of soil that found had a dominant smooth material silt-sized, with the appearance colored dark brown ground on volcanic rock and blackish brown on coral limestones. On the slopes there are shrub vegetation, grass, and high rainfall, so rooting system becomes one of the factors causing water absorption into the fracture or the pores of rock. Data of the earthquake indicates relatively low seismicity although in 2006 there was an earthquake with great strength. Slopes water conditions is not dominate, from the mapping results only 10 of 79 observation points that have water seepage on the slope. Based on Integrating Remote Sensing and Field Data, scoring in 79 observation points of research area is included in high landslide vulnerability zone with weighted value ranging from 2,41–2,85 referring to ministerial regulation PU No.22/PRT/M/2007. The possibility of landslides direction relative to southwest-northeast and north-south, so potentially close the inter-provincial road access. Based on KEPPRES No. 32, 1990 that the disaster-prone area are protected area which need to protected for humans and their activities cause by nature or human eror. Disaster-prone area identified often and high potentially sustainable occur disasters such as volcano eruption, earthquake, and landslide. Kulonprogo regency are the landslide disaster area. There are four area that have been a high potentially landslide at Kulonprogo regency. Samigaluh district, Kokap district, Girimulyo district, and Kalibawang district. Purwoharjo village is one of the villages in the Sub-District of Samigaluh that has a high potential for landslides. Every rainy season is the most frequent occurrence of landslide in Purwoharjo Village (Suara Merdeka, 2015). Therefore, the study of landslide vulnerability zones based on 7 parameters from Minister of Public Works Regulation are slope (30%), soil condition (15%), constituent rock (20%), rainfall (15%), vegetation (10%), seismicity (3%) and slope water system (7%) which is then supported by soil laboratory analysis and integrated with Landsat 8 and Google Earth imagery data. This study has the objective of mapping the landslide susceptibility zones and predicting future landslides.

Geo-informatics for landslide risk zone assessment in Wang Sa Pung Amphoe, Loei Province have investigated the influencing factors for landslide occurrence, and apply geo-informatics for landslide risk identification, in Wang Sa Pung Amphoe, Loei Province. The 9 influencing factors for landslide occurrence, suitable for analysis with geographic information systems (GIS), are maximum daily rainfall, slope, elevation, land use, NDVI, distance from the fault, distance from the river, soil drainage and the rock type. Integration of GIS with analysis hierarchy process (AHP), the areas prone to landslides in the study area can be classified to landslide high-risk areas of 107.18 square kilometers (47.04 %), landslide moderate-risk areas as the area of 98.26 square kilometers (43.13 %). The area of 60.40 square kilometers of Nong Ngui tambon, can be identified to high risk of landslide area and 46.13 sq.km. are moderate risk of landslide area. The 48 villages classify to the risk of landslide area. Found that 8 villages area high risk of landslide, 5 villages locate in Phu Rua Amphoe and 3 villages locate in Wang Sa Pung Amphoe.

เทคโนโลยีภูมิสารสนเทศเพื่อการประเมินพื้นที่เสี่ยงภัยแผ่นดินถล่มในเขตอำเภอวังสะพุง จังหวัดเลย มีวัตถุประสงค์เพื่อศึกษาคุณลักษณะและปัจจัยที่มีอิทธิพลต่อการเกิดแผ่นดินถล่ม และเพื่อประยุกต์เทคโนโลยีภูมิสารสนเทศเพื่อวิเคราะห์หาพื้นที่เสี่ยงภัยต่อการเกิดแผ่นดินถล่มในพื้นที่อำเภอวังสะพุง จังหวัดเลย จากการศึกษางานวิจัยที่เกี่ยวข้องพบปัจจัยที่มีอิทธิพลต่อการเกิดแผ่นดินถล่มที่เหมาะสมสำหรับการวิเคราะห์ร่วมกับระบบสารสนเทศภูมิศาสตร์ จำนวน 9 ปัจจัย ได้แก่ ปริมาณน้ำฝนสูงสุดรายวัน ความลาดชัน ระดับความสูงของพื้นที่ การใช้ประโยชน์ที่ดิน ดัชนีพืชพรรณ (NDVI) ระยะห่างจากรอยเลื่อน ระยะจากแม่น้ำ การระบายน้ำของดิน และลักษณะหิน และการวิเคราะห์หาพื้นที่เสี่ยงภัยด้วยระบบสารสนเทศภูมิศาสตร์ ประมวลผลร่วมกับการให้ค่าน้ำหนักและค่าคะแนนโดยใช้กระบวนการลำดับชั้นเชิงวิเคราะห์ (analysis hierarchy process, AHP) ผลการศึกษาพบว่าพื้นที่เสี่ยงภัยดินถล่มส่วนใหญ่อยู่เขตลุ่มน้ำ อำเภอวังสะพุง จังหวัดเลย ในระดับความเสี่ยงสูง 107.18 ตารางกิโลเมตร (47.04 %) พื้นที่มีความเสี่ยงระดับปานกลาง 98.26 ตารางกิโลเมตร (43.13 %) พื้นที่ส่วนใหญ่ของตำบลหนองงิ้ว เป็นที่เสี่ยงภัยดินถล่มระดับสูง 60.40 ตารางกิโลเมตร และเป็นที่เสี่ยงภัยดินถล่มระดับปานกลาง 46.13 ตารางกิโลเมตร จำแนกความเสี่ยงในระดับหมู่บ้านที่เสี่ยงภัยจากดินถล่มทั้งสิ้น 48 หมู่บ้าน ระดับความเสี่ยงภัยสูงจากดินถล่ม จำนวน 8 หมู่บ้าน อยู่ในอำเภอภูเรือ 5 หมู่บ้าน และอยู่ในอำเภอวังสะพุงอีก 3 หมู่บ้าน

Evaluating the performance of landslide susceptibility models is needed to ensure their reliable application to risk management and land-use planning. When results from multiple models are available, a comparison of their performance is necessary to select the model which performs better. In this paper, different techniques to evaluate model performance are discussed and tested using shallow landslide/debris-flow susceptibility models recently presented in the literature (Carrara, A., Crosta, G.B., Frattini, P., 2008. Comparing models of debris-flow susceptibility in the alpine environment. Geomorphology 94 (3–4), 353–378). Moreover, an evaluation technique based on the minimization of costs that may arise from the adoption of the model as a land management regulatory tool, is presented. The results of the application show that simple statistics such as Accuracy, Threat score, Gilbert's skill score, Pierce's skill score, Heidke skill score, and Yule's Q are problematic as they need to split the classified objects into two classes (e.g., stable/unstable) by defining an a-priori value of cutoff susceptibility, which is often not trivial. ROC curves and Success-Rate curves are cutoff-independent and can be used to efficiently visualize and compare the performance of models, but do not explicitly include classification costs. In addition, Success-Rate curves, under certain conditions, can be misleading when applied to grid-cell models. Cost curves include costs and a-priori probabilities, and are suitable for landslide susceptibility model performance evaluation from a practical point of view.

En el contexto del ordenamiento territorial entre los años 1998 y 2000 el servicio de extensión universitaria de la Universidad Industrial de Santander elaboró un modelo en ArcGis para evaluar el la amenaza por remoción en masa para el municipio de Piedecuesta. Este modelo requirió el levantamiento a escala 1:25000 de los mapas de materiales geológicos, morfodinámica, cobertura vegetal, actividad minera, pendientes, isoyetas, fallas geológicas del área del municipio. El mapa de amenaza generado hizo parte de los insumos para elaborar el Plan de Ordenamiento Territorial del municipio, en el cual quedó consignado las limitaciones para el uso del suelo del casco urbano por amenaza de remoción en masa. En ese mapa el sector más oriental del Barrio San Cristóbal quedó zonificado con amenaza por remoción en masa.

Durante la temporada de lluvias del año 2010 ocurrió un deslizamiento en el sector este del barrio San Cristóbal el cual afectó a 18 viviendas del barrio con agrietamientos y volcamiento. En el año 2011 se realizó solicitud por parte del municipio de Piedecuesta al ICP, de realizar una visita y concepto técnico sobre dicho deslizamiento. En el informe de visita se consignó el diagnóstico del deslizamiento como de tipo rotacional con un área deslizada de cerca de dos hectáreas y un escarpe entre 10 y 15 m de altura, las viviendas afectadas se ubican en el pie del deslizamiento cerca a la superficie de falla, el movimiento del cuerpo del deslizamiento hizo empuje lateral y generó agrietamiento, volcamiento de muros y levantamiento del piso de las viviendas. Un tramo de 120 m de vía veredal fue desplazado y las veredas quedaron incomunicadas. Fue un deslizamiento relativamente lento que permitió la evacuación de las familias. La causa principal la existencia de una falla activa, presencia de suelos profundos y presencia de niveles freáticos altos, así como recurrencia de sismicidad que actúa como agente disparador.

En el informe de visita se consignaron las recomendaciones para mitigar dicho deslizamiento: Reubicación de familias, determinar profundidad de la superficie de falla mediante sondeos, extracción y disposición en escombreras del material de suelo del cuerpo del deslizamiento quitando peso para disminuir el empuje, terraceo y construcción de sistema de drenaje integrado al sistema pluvial del barrio, empradización del sector y construcción de barrera de contención. Estas obras se están realizando en la actualidad y se espera con esto solucionar el problema del deslizamiento.

Como conclusión podemos tener que la gestión del riesgo por fenómenos de remoción en masa en Colombia y la gestión de presupuesto para la mitigación es una necesidad apremiante en todos los municipios de montaña. Se tienen planes de ordenamiento territorial con la identificación de las zonas de amenaza, al parecer no ha habido destinación de recursos para el desarrollo de estudios detallados en las áreas identificadas como de amenaza por remoción en masa o programas a largo plazo para la gestión del riesgo y disminución de la amenaza, en muchos municipios aún trabajamos al día día mediante la atención de emergencias.

Sikkim is a disaster prone State. Indian Himalayan Region (IHR) faces complexity of landslide hazards of unreliable magnitudes above its different regions as one of the major natural hazards. Sikkim Himalaya in the eastern IHR also experiences the landslide troubles due to a geologically brittle host terrain coupled with heavy rainfall as well as other natural and anthropogenic factors. Mountain highways/roads are the single most important infrastructure, which suffer deficiently due to landslides and therefore affecting the regular traffic in the hills. Such events lead to problems of road and other communications particularly during monsoons with adverse impacts on economic/commercial as well as development related activities.
Landslides happen as natural phenomena in hilly terrains and also due to disturbances reasons with construction activities, e.g., housing and transportation. Natural slopes which contain traditional a stability by the geographical and geotechnical features of the area obtain troubled through human procedures like mining, deforestation and road structures which perforce are required to fulfill the development desires of the region. Failures of slopes generally happen during major earthquakes and apart from liquefaction, frequently constitute the most visible and damaging landslides.  The whole state of Sikkim is very vulnerable to landslide due to its structurally controlled extremely scrutinized undeveloped geography, delicate rock condition, high rainfall escorted by occurrence earth trembles.
The study has been carried out at Gangtok area, East District of Sikkim, the total area of study is 30.25 sq. km. A landslide hazard analysis has been done for whole Gangtok area. In Landslide Zonation study, two elements have been investigated. First is geological and topographic factor that contain landuse, lithology, slope class, slope aspect, elevation, drainage etc. Second is the activating factor which contains rainfall. While the factor planned under topographic parameters have been measured as basic inputs for Landslides Hazard Zonation study. Landslide disasters in Himalaya have made fabulous impact on the society. Remote Sensing and GIS techniques play a significant role in Landslide Hazard Zonation mapping. A Landslide Hazard Zonation (LHZ) map is helpful for selecting appropriate sites to implement development schemes in the hilly terrains, which can be adopted for suitable mitigation procedures in the unstable hazard prone areas?
The approach has been the assessment of terrain condition below which landslides contain happen in the earlier period and with those exact terrain situations, forecasts future landslide vulnerability areas. Remote sensing methods are used for take out different thematic particulars counting obtainable landslide zones, roads, drainage network, and landuse/land cover pattern from satellite data of Indian Remote Sensing Satellites. Visual interpretation by appropriate assists and image processing is prepared by appropriate software. This goes among the presumption to under the consistent triggering factor valid for the whole area hazard vulnerability has been investigated as a function of host geo-environmental conditions. All the parameters are subjected to divaricate statistical landslide hazard analysis under a suitable Geographic Information System (GIS) platform. Landslide in the Indian Himalayan Region (IHR) are the forms of natural hazards more due to host terrain conditions such as geology, geomorphology, hypsography and climate etc. In Sikkim, high rainfall and cloudbursts are largely responsible for reactivation of old landslides as well as activating new landslides. Such mass movements are one of the worst forms of natural hazards, which affect the area with settlements and important infrastructure like road. These studies have been done around the Gangtok area.

Nous avons développé des modèles pour évaluer les menaces naturelles principales auxquelles est exposé Delmas 32. La menace sismique, la menace d’inondation et la menace d’instabilité des pentes ont été retenues comme celles qui pourraient affecter le plus le quartier, surtout en tenant compte des caractéristiques du terrain et des conditions de vulnérabilité présentes. En apparence et suivant les donnés disponibles, la liquéfaction des sols sableux ne parait pas plausible de se matérialiser de manière importante. Tous nos commentaires et déductions sur l’instabilité des pentes sont générés à partir d’observations géologiques-géotechniques en surface. Il faudra les vérifier au moyen d’études spécifiques de terrain en profondeur (i.e. sondages carottées, SPT, résistivité électrique, sismique de réfraction, essais de laboratoire, calculs, etc.). De ceci et à partir de l’observation des affleurements dans les berges des ravines, nous avons constaté que la verticalité de leur falaises est directement liée au degré élevé de résistance au cisaillement des conglomérats qui les constituent. L’absence de nappe phréatique dans la couche supérieure des conglomérats favorise le maintien des pentes. Par contre, les couches d’argilite bien que de faible plasticité et relativement peu sensibles à l’eau et donc que leur résistance ne soit pas susceptible de subir de fortes chutes dues à la saturation. Cependant, elles sont fissiles et après plusieurs cycles d’humidification-dessiccation, elles deviennent susceptibles à l’érosion. Une condition critique à considérer est le cas de la zone affecté par le macro-glissement de terrain qui s’est produit en 1989 au sud du quartier de Delmas 32 (voir chapitre 3.2.2) et en partie causé par le mouvement d’un remblai mal compacté et qui aujourd’hui se trouve très densément peuple. Il existe une couche d’argile riche en montmorillonite, qui, lorsque saturée par une nappe phréatique pérenne se caractérise par une faible résistance au cisaillement. Celle-ci a été vraisemblablement à l’origine du macro-glissement de Delmas 32 de 1989. À cause de l’ampleur et de la forte densité des constructions actuelles, il n’est pas possible d’évaluer le degré d’activité, le taux de mouvement ni la possibilité d’une réactivation soudaine de ce mouvement de terrain. Le seul moyen de diagnostiquer la probabilité de reprise des mouvements serait issu d’une campagne d’études géotechniques, hydrogéologiques et géophysiques permettant de modéliser la masse glissante et ses propriétés mécaniques et hydrauliques. Ce macro-glissement n’est pas analysable avec la méthodologie Mora-Vahrson, qui vise plutôt à la potentialité du développement de glissements de plus petite échelle. Les analyses de stabilité géotechnique des pentes réalisées confirment les observations de terrain, à l’effet que les pentes sub-verticales des ravines sont assez stables à court terme, pourvu que l’activité humaine n’engendre pas des changements radicaux dans la condition du terrain. Cependant, les écoulements torrentiels à haut débit d’énergie dans les ravines, continueront à se présenter chaque fois que les pluies dépasseront une cinquantaine de millimètres par heure. Dans ces conditions, il faudrait envisager que les talus des ravines seront continuellement minés et à long terme ils peuvent devenir instables si aucune protection hydraulique adéquate contre l’érosion n’est assurée: d’une part au pied par le courant des rivières et d’autre part sur les crêtes contre le ruissellement de surface, au moyen de fossés de drainage et d’assainissement et en réparant les fuites des tuyauteries d’aqueducs pour éviter des écoulement qui se jettent sur les pentes et l’humidifient les terrains. Les méthodes de prévention et mitigation qui s’imposent dans ces zones exposées consistent essentiellement à améliorer le drainage pour éviter leur infiltration dans le sol: i) drainage des eaux de pluie au moyen de fossés d’assainissement pour éviter les stagnations; ii) canalisation des eaux usées qui sont actuellement rejetées directement sur les talus; iii) drainage souterrain en cas de présence de nappes phréatiques. Pour vérifier la stabilité générale des pentes, à long terme il faudrait réaliser, pour chaque endroit en particulier, des analyses de stabilité spécifiques. La vérification des conditions de stabilité et ses facteurs de sécurité peuvent être réalisés par des exercices de retro-calcul et de sensibilité paramétrique au moyen des logiciels tels que STABL®, SLOPE/W 2007®, ou autres. Il est clair que la fiabilité des résultats de ces calculs sera fonction de la qualité de la prospection géotechnique respective (reconnaissances de terrain, sondages, analyses de laboratoire, etc.). Les études hydrologiques et hydraulique menés jusqu’à présent ont permis de produire des scénarios et modélisations déterministes des zones inondables, au moyen des logiciels HECRAS et HECHMS. Il a été possible aussi de réaliser des zonages préliminaires de la menace d’inondation à Delmas 32. Dans le cas de la menace d’inondation, il est à considérer le fait que l’abondance et le manque de contrôle des déchets solides, mise à part les considérations environnementales évidentes et graves, constitue un problème majeur de multiplication et d’aggravation de la menace d’inondation, surtout à cause de leur influence dans les systèmes de drainage en général.
Dans les étapes futures d’étude, il faudra considérer trois scénarios d’analyse supplémentaires: i) Situation actuelle avec blocage par des déchets solides dans le système de drainage primaire et sous les ponts; ii) Situation avec les structures actuelles, sans blocage par des déchets solides; iii) Situation avec les structures actuelles redimensionnées et sans déchets solides. Ces scénarios doivent s’accompagner de guides pour la conception des mesures structurelles et non-structurelles, la relocalisation des bâtiments qui se trouvent dans les zones inondables et le redimensionnement des structures hydrauliques à capacité hydraulique insuffisante. Il faut aussi envisager d’interdire la réoccupation dans des zones inondables, gérer les déchets solides et d’implanter des programmes d’éducation et de gestion du risque pour diminuer la vulnérabilité face aux inondations. Par superposition des informations correspondantes à l’exposition des enjeux aux menaces naturelles, il a été possible de construire des cartes préliminaires où l’on peut identifier les niveaux combinés des menaces de glissement et d’inondation. Par convention, nous avons établit les indicatifs suivants sur nos fichiers SIG:
• Glissement = G (identifié par la méthode Mora-Vahrson)
• Inondation = I (suivant les modèles HEC)

The analytical approach in the present study, based on the availability of necessary data and
information, was set in order to better understand the potential in geomorphology and the geographical
risk phenomena in the Niraj Basin, by the studying of the generating factors, of the qualitative and
quantitative characteristics, as well as of their effects in the geographical environment.
The solutions and results of the applicative geomorphological analysis ca be put into practice, hence
they have as main characteristics their applicability. Developing the applicability nature of the
geomorphological research becomes essential, as an optimal relief valorisation and the offering of
veridical solution for solving the identified problems are desired.
The motivation behind choosing the present theme stems from the passion for Geomorphology and
the study of geographic risk phenomena, as well as from the desire to study the Niraj Basin with the
purpose of applying specific principles and of identifying the applicability of the geomorphology
methods, used for the obtaining of practical solutions to the identified dysfunctions. Hence the present
paper is structured into three main parts...

Currently, regional coseismic landslide hazard analyses require comprehensive historical landslide
inventories as well as detailed geotechnical data. Consequently, such analyses have not been possible where
these data are not available. A newapproach is proposed herein to assess coseismic landslide hazard at regional
scale for specific earthquake scenarios in areas without historical landslide inventories. The proposed model
employs fuzzy logic and geographic information systems to establish relationships between causative factors
and coseismic slope failures in regions with well-documented and substantially complete coseismic landslide
inventories. These relationships are then utilized to estimate the relative probability of landslide occurrence
in regions with neither historical landslide inventories nor detailed geotechnical data. Statistical analyses
of inventories from the 1994 Northridge and 2008 Wenchuan earthquakes reveal that shaking intensity,
topography, and distance from active faults and streams are the main controls on the spatial distribution of
coseismic landslides. Average fuzzy memberships for each factor are developed and aggregated to model the
relative coseismic landslide hazard for both earthquakes. The predictive capabilities of the models are assessed
and show good-to-excellent model performance for both events. These memberships are then applied to the
1999 Chi-Chi earthquake, using only a digital elevation model, active faultmap, and isoseismal data, replicating
prediction of a future event in a region lacking historic inventories and/or geotechnical data. This similarly
results in excellent model performance, demonstrating the model’s predictive potential and confirming it can
be meaningfully applied in regions where previous methods could not. For such regions, this method may
enable a greater ability to analyze coseismic landslide hazard from specific earthquake scenarios, allowing for
mitigation measures and emergency response plans to be better informed of earthquake-related hazards.

Soil resources of the Earth are vital for preserving life on this planet due to their unique ecosystem services. Etymologically, humus, human, and humble share, for a good reason, the same root. These resources are, however, limited and non-renewable at a reasonable time scale. In addition, soils are now threatened, as evidenced in the fact that in recent years, the Technosphere (i.e., all material production generated by human activities) has begun to exceed the Biosphere at an accelerated rate, both in weight and diversity. Despite the demand and research efforts to address these problems innovatively, there are currently no onboard sensors dedicated to soils. Nevertheless, operational sensors can provide valuable and sometimes irreplaceable information about the properties and the state of the uppermost layer of the soil, which is called “topsoil”. This layer, ranging from 5 to 30 cm, is usually the first affected by threats such as organic matter decline, erosion, compaction, salinization, contamination, sealing, landslides, or land subsidence. Additionally, climate change can have serious effects on the water and energy budgets of the topsoil affecting the Earth Critical Zone. Numerous publications have already shown that remote sensing technologies can contribute to estimate, map, and monitor topsoil properties and its state. This Special Issue invites you to highlight significant achievements so far, as well as the challenges and limits of current remote sensing technologies to provide useful information on topsoil. We also invite you to show new opportunities offered by the present constellation of satellites, along with data processing advancements that address research gaps you have identified and/or support various policies. (https://www.mdpi.com/journal/remotesensing/special_issues/Characterization_Topsoil_RS)

Active deformation zones on the earth surface continue to threaten the life in the past, present and the future. The
main two of these disasters are earthquake and landslide that are the reason of most human loss. The geological
and multi-disciplinary research related to these kinds of disasters that occurred in the early 20th century has
gained further momentum with events that affect people's lives significantly. Thanks to scientific andtechnological advances, different kinds of studies have led to new insights to the earth sciences. Among these
studies especially in the last decades, Interferometric Synthetic Aperture Radar (InSAR) technique has become
an effective geodetic method for determining surface deformation. This technique determines deformation rate
from various surface movements using radar images. From the point of view of examining spatial distribution of
surface deformations, we search for landslides in our country. Many urban areas in Turkey are affected by
landslides. For example, in Denizli, Babadag town center and close surroundings, various landslides have been
observed. We examined landslides which are located in Gundogdu district. Gundogdu landslide is significant for
our study due to the density of the residential area. From the previous studies a movement about 4-10 cm per
year is determined.
In this study, it is aimed to detect amount and direction of horizontal movement occurred in Babadag Gundogdu
district based on InSAR technique. This study shows that the deformations are still developing in the different
parts of Babadag and its surroundings. For mapping deformations through interferograms, ALOS PALSAR radar
images were delivered from the European Space Agency under Category-1 project (Project ID: 14218) and some
image pairs were created to examine the surface deformations within the study area. The interferograms which
were processed with the sarproz software showed high coherence, and the surface deformations were interpreted
using these interferograms.
Keywords: Landslide, InSAR, Babadağ (Gündoğdu), ALOS PALSAR

A Mw=7.0 earthquake occurred in Haiti on January 12, 2010 (IMMmax=X) claiming at least
230,000 lives, injuring 100,000 people and leaving 600,000 homeless. They add to another sizeable portion of
the population already affected by previous disasters and political upheaval. It is not the first time -nor will be
the last- that a major earthquake hits Haiti. Damage and economic losses amount to over US$ 8 billion (120%
of 2009 GNP). The earthquake also triggered liquefaction and more than 7,000 landslides, most of them rock
and soil slides on 25-65° slopes within heavily fractured limestone, weathered basalt and basaltic breccia. The
most common slope movements were slow/continuous deformation-translation (curved/planar) slides and rapid
movements (rock-falls, regolith slumps, torrential debris flows), sometimes reactivated by intense rainfall and
aftershocks. Considering the need for a rapid determination of slope instability hazards to assist the reconstruction
process, “screening” macro-zonation methodologies were applied. The precision of basic data conditioned
the quality, accuracy and reliability of the outputs. These preliminary views must be verified in situ and refined
as new site specific data becomes available. The results must be used with discernment, being clear that these
are not slope stability quantitative determinations but only a first attempt at identifying areas prone to slope instability.

ABSTRACT Homeowners who live near or on steep slopes of the Traverse Mountains along the Wasatch front in southern Salt Lake City, Utah (USA) are at risk where development of “master-planned communities” has been permitted on known landslide deposits since 2001. Some of the largest landslides in the state of Utah are being modified as road construction and residential development progresses. This paper reviewed the setting of the landslide-prone areas and used Geographic Information Systems (GIS) spatial tools to assess the value of local developments built on mapped slide features. Dataset overlays
were compiled to determine the vulnerability of residences, and to quantify potential monetary loss from a future landslide event. The key elements at risk include property, as well as the population, economic activities, and public services of a given region. An initial conservative figure calculated for the vulnerability of residents owning property exceeds $500 million for the Traverse Mountains region of Draper City, based on 2007 property values recorded at the Salt Lake County Assessors Office. In developing this area, the failure to consider existing and potential hazards has caused a myriad of tensions among local government officials, planners, financiers, state regulators, consultants, developers, realtors, and homeowners.

Despite increasing efforts in the mapping of landslides using Sentinel-1 and-2, research on their combination for discerning historical landslides in forest areas is still lacking, particularly using object-oriented machine learning approaches. This study was accomplished to test the efficiency of Sentinel-derived features and digital elevation model (DEM) derivatives for mapping old and new landslides, using object-oriented random forest. Two forest subsets were selected including a protected and non-protected forest in northeast Iran. Landslide samples were obtained from CORONA images and aerial photos (old landslides), and also field mensuration and high-resolution images (new landslides). Segment objects were generated from a set combination of Sentinel-1A, Sentinel-2A, and some topographic-derived indices using multiresolution segmentation algorithm. Various object features were derived from the main channels of Sentinel images and DEM derivatives in the seven main groups, including spectral layers, spectral indices, geometric, contextual, textural, topographic, and hydrologic features. A single database was created, including landslide samples and Sentinel-and DEM-derived object features. Roughly 20% of landslide-affected objects and non-landslide-affected objects were randomly selected as an input for training the random forest classifier. Two-thirds of the selected objects were assigned as learning samples for classification, and the remainder were used for testing the accuracy of landslide and non-landslide classification. Results indicated that: (1) The sensitivity of mapping historical landslides was 86.6% and 80.3% in the protected and non-protected forests, respectively; (2) the object features of Sentinel-2A and DEM obtained the highest importance with the total scores of 55.6% and 32%, respectively in the protected forests, and 65.4% and 21% respectively in the non-protected forests; (3) the features derived from the combination of Sentinel-1 and-2A demonstrated a total importance of 10% for mapping new landslides; and (4) textural features were obtained in approximately two-thirds of the total scores for mapping new landslides, however a combination of topographic, spectral, textural, and contextual features were the effective predictors for mapping old landslides. This research proposes applying a synergetic analysis of Sentinel-and DEM-derived features for mapping historical landslides; however, there are no uniformly pre-defined influential variables for mapping historical landslides in different forest areas.

An 8 Richter Scale (RS) earthquake struck West Sumatra on Wednesday, 30 September 2009, at 17.16 pm which led to huge number of landslides. Hence a comprehensive landslide susceptibility mapping (LSM) should be produced in order to reduce the damages to people and infrastructures. In the international landslide literature, various statistical methods such as frequency ratio (FR) and logistic regression (LR) have been widely used individually for LSM, but they have some weaknesses. FR which is able to perform bivariate statistical analysis (BSA) assesses the influence of classes of each conditioning factor on landslide occurrence. However, the correlation between the factors is mostly neglected. On the other hand, LR is able to analyze the relationship among the factors while it is not capable to evaluate the classes of each landslide conditioning factor. This paper aims to propose an ensemble method of FR and LR in order to overcome their weak points. For LSM, a landslide inventory map with a total of 87 landslide locations was extracted from various sources. Then the landslide inventory was randomly divided into two datasets 70% for training the models and the remaining 30% was used for validation purpose. The landslide conditioning factors consist of: altitude, curvature, river, SPI, rainfall, soil type, soil texture, land use/cover (LULC), peak ground acceleration (PGA), geology, slope, aspect, lineament and topographic wetness index (TWI). Four PGA of 7.5, 8, 8.6 and 9 were acquired and PGA 8 which was related to the 2009 earthquake was used to generate the model. Finally, the produced landslide susceptibility maps were validated using an area under the (ROC) curve method. For the model which was derived by PGA 8, the validation results showed 84% and 78% success and prediction rates respectively. Furthermore, the prediction rates for the models made by PGA 7.2, 8.6 and 9 are 79%, 78% and 81% respectively. The result proved the reasonable efficiency of the proposed method for earthquake induced landslide susceptibility mapping. Also the proposed ensemble method can be used in other hazard studies as it is capable to produce rapid and accurate assessment for disaster management and decision making.

High-resolution topographic surveying is traditionally associated with high capital and logistical costs, so that data acquisition is often passed on to specialist third party organizations. The high costs of data collection are, for many applications in the earth sciences, exacerbated by the remoteness and inaccessibility of many field sites, rendering cheaper, more portable surveying platforms (i.e. terrestrial laser scanning or GPS) impractical.

This paper outlines a revolutionary, low-cost, user-friendly photogrammetric technique for obtaining high-resolution datasets at a range of scales, termed ‘Structure-from-Motion’ (SfM). Traditional softcopy photogrammetric methods require the 3-D location and pose of the camera(s), or the 3-D location of ground control points to be known to facilitate scene triangulation and reconstruction. In contrast, the SfM method solves the camera pose and scene geometry simultaneously and automatically, using a highly redundant bundle adjustment based on matching features in multiple overlapping, offset images.

A comprehensive introduction to the technique is presented, followed by an outline of the methods used to create high-resolution Digital Elevation Models (DEMs) from extensive photosets obtained using a consumer-grade digital camera. As an initial appraisal of the technique, an SfM-derived DEM is compared directly with a similar model obtained using Terrestrial Laser Scanning. This intercomparison reveals that decimetre-scale vertical accuracy can be achieved using SfM even for sites with complex topography and a range of land-covers. Example applications of SfM are presented for three contrasting landforms across a range of scales including; an exposed rocky coastal cliff; a breached moraine-dam complex; and a glacially-sculpted bedrock ridge.

The SfM technique represents a major advancement in the field of photogrammetry for geoscience applications. Our results and experiences indicate SfM is an inexpensive, effective, and flexible approach to capturing complex topography.

Rock fall hazard assessment is a very demanding problem because of the complexity of the involved physics and its intrinsic stochasticity. New powerful tools, developed in the last few years, are characterized by different degrees of completeness, models, and algorithms. In the following, the modelling approach developed through the years within the code Hy_Stone is presented. Some issues related to the sensitivity to 3D topographic descriptions, the effects of stochasticity on model results and the calibration of 3D rockfall simulation are presented.

In this study, it was aimed at evaluating the slope stability conditions in a residential area exposed to two landslides in the past by using two-and three-dimensional limit equilibrium analyses. Two separate, but interdependent, landslides were observed in the investigated area. In 1992 and 1994, two landslides occurred in the region after heavy precipitation and caused damages on the houses and infrastructures. An extensive field work was performed to obtain input parameters for the analyses. In addition, an unmanned aerial vehicle was flown to obtain a three-dimensional view of the landslide area for better understanding of the past failures. The landslides occurred in a flysch-type material representing complex geological characteristics. Hoek-Brown failure criterion and Geological Strength Index were chosen for the strength and visual definition of the geological unit. Since the landslide triggering factor was precipitation, the analyses were focused on the water conditions causing the failure. Sensitivity and back-analyses were performed to obtain the conditions of failure. It was revealed that a high pore pressure ratio was needed to trigger the landslides. However, the second landslide was failed with a lower pore water pressure and the current topography was determined to be on the edge of failure with a slight increase in the pore pressure ratio. In other words, the study area was still found to be prone to possible landslides in the future.

Выявлена различная степень активности оползневых процессов для разных участков Затонского оползня – одного из самых крупных на территории Саратова. Установлена ключевая роль антропогенного фактора в активизации оползневых смещений. Южный участок оползня около пятидесяти лет остается в неукрепленном состоянии, и в настоящее время находится в стадии крайне неустойчивого равновесия. Показано современное использование оползневых земель и причиненный ущерб.
The different state of activity of landslide processes for different areas of landslide Zatonsky, one of the largest on the territory of Saratov, was revealed. The key role of anthropogenic factor in the process of activation of landslide displacements is set. During the fifty years, the southern portion of the landslide have been being in the unreinforced state. Currently, he is being very unstable equilibrium. Modern use of land and landslide damage was shown.

Landslide is very common problem in the Himalayan region that is tectonically very active. Nainital's geographic site (29°2'-29°37' N and 78°51'-79°59' E) and its condition allow for landslides to occur much more often than in any other region of the Himalaya. Being the youngest mountain system of the world, it constitutes a fragile network of unstable slopes with a major geo-hazard of landslides. Three major tectonic features (MCT, MBT and MFT) running all along the whole Himalayan belt are capable of generating major to large earthquakes in the region. Each type of landslide including earthquake induced landslide occurs in a particular suite of geologic environments. In addition to various static factors responsible for instability of slopes, earthquakes are to be considered as a major triggering factor for the occurrence of landslides and first time used in rating scheme for landslide hazard zonation in this region. To assess the potential landslide hazard distribution in the considered region, we have taken toposheet of the region as base map for delineation of the whole Nainital region into smaller areas (facets) and other based on the certain tectonic and geologic environments. An empirical method, which pays landslide hazard evaluation factor (LHEF) rating scheme has been applied in each facet. By calculating total estimated hazard (TEHD) facet-wise by adding ratings of all causative factors, landslide hazard zonation (LHZ) map is prepared. On the basis of TEHD, the LHZ map is divided into 5 categories, namely, very low hazard (VLH), low hazard (LH), moderate hazard (MH), high hazard (HH) and very high hazard (VHH) and presented in the final map.

Digital elevation models (DEMs) are considered an imperative tool for many 3D visualization applications; however, for applications related to topography, they are exploited mostly as a basic source of information. In the study of landslide susceptibility mapping, parameters or landslide conditioning factors are deduced from the information related to DEMs, especially elevation. In this paper conditioning factors related with topography are analyzed and the impact of resolution and accuracy of DEMs on these factors is discussed. Previously conducted research on landslide susceptibility mapping using these factors or parameters through exploiting different methods or models in the last two decades is reviewed, and modern trends in this field are presented in a tabulated form. Two factors or parameters are proposed for inclusion in landslide inventory list as a conditioning factor and a risk assessment parameter for future studies.

Traditionally, earth scientists assess landslide occurrence on the basis of geomorphological investigations carried out through aerial photograph interpretation and fieldwork. Conversely, local administrators primarily evaluate the impact of natural catastrophes, such as landsliding, on the basis of historical records and data. Owing to the substantial difference in the structure and spatial density of these two types of information, it is difficult to compare them directly and few investigators have attempted this. We compared landslide information derived from geomorphological mapping and historical data in a pilot area (the Staffora river basin, northern Italy). To do this we generated two multivariate statistical models where the dependent variable was either the mapped landslide deposits (geomorphological model), or the historical sites affected by landslide-induced damage (historical model). By quantitatively comparing these two model maps, we demonstrate that the geomorphological model performs better in terms of percentage of terrain units correctly predicted as stable or unstable. The historical model underestimates landslide hazard mainly where human structures are lacking. However, it highlights slopes where landslide movements take place with a high frequency at the temporal scale of human life. Hence, the joint use of these two models may facilitate the knowledge of the overall instability conditions of a given region and the identification of the landslides that are most frequently reactivated.

The present study uses Remote Sensing and GIS for finding susceptible zones of landslide hazards in the
Tehri region which has an area of 798 sq.km. Six-factor layers responsible for landslide occurrence,
such as road, slope, lineaments, geology, drainage, landuse are assigned membership functions and
appropriate rules were assigned to them in Fuzzy Inference System. Frequency Ratio Method is applied
in the same area and both the method is assessed for the accuracy. The Fuzzy Inference based landslide
susceptibility mapping has been classified into five zones. These results have been compared with the
landslide hazard zonation map generated by frequency ratio method and the results were presented in
detail. A comparison of the total area under each class in both the methods has been revisited with the
landslide density in each class of hazard. It has been found that the frequency ratio has given better
results than the fuzzy method. It is to be highlighted that the present study has not used any prior
information into the Inference system for hazard zonation however in the frequency ratio method
landslide inventory (previous instances of landslide occurrences in the study area) was used as one
parameter for hazard zonation.

The Indo-Myanmar Ranges (IMR), known as an accretionary prism, lies between the Kaladan Fault (subduction suture) in the west and Kabaw Fault (the boundary between flysch units and molasse units) in the east is very important to interpret the paleogeographic evolution of the major continents, restoring the paleogeography and plate boundary evolution between the India Plate and West Myanmar Block. The present study explained compression along the Shillong Massif into the IMR with a conceptual model that involves 6-stages of deformation processes. The Kabaw Fault along the eastern rim of Kabaw Valley or the western border of the Kabaw Formation occurs as both an east-dipping thrust and a dextral strike-slip fault. The tectonic model proposed for the IMR is a
double-wedge system, in which retro-wedge and east-dipping Kabaw Fault are interrelated to form Nappe of Triassic unit (Thanbaya Formation) with double plunging synclines of Chindwin and Minbu-Salin sub-basins. The
Jurassic unit (Kyauksitchaung Formation) is newly found along the eastern base of the IMR as a lithostratigraphic unit and a window structure under the Nappe of the Triassic unit. The alignment of the Kaladan Fault is
newly proposed as a suture zone revealed by the window structures of the Oligocene flysch unit under the Nappe of Neogene units on the onshore area, and localities of the mud volcanoes and structural trend of small islands at the offshore area. The formation of circular structures on the Ramree Archipelago is explained by superimposed folding with heterogenous simple shear deformation of the dome and basin structures due to the NW movement of the Broken-Block of IMR colliding with foreland basins including Chittagong-Tripura Fold Belt (CTFB) and
Baronga (Boronga) Islands.

The Himalayan region and hilly areas face severe challenges due to landslide occurrences during the rainy seasons in India, and the study area, i.e., the Rudraprayag district, is no exception. However, the landslide related database and research are still inadequate in these landslide-prone areas. The main purpose of this study is: (1) to prepare the multi-temporal landslide inventory map using geospatial platforms in the data-scarce environment; (2) to evaluate the landslide susceptibility map using weights of evidence (WoE) method in the Geographical Information System (GIS) environment at the district level; and (3) to provide a comprehensive understanding of recent developments, gaps, and future directions related to landslide inventory, susceptibility mapping, and risk assessment in the Indian context. Firstly, 293 landslides polygon were manually digitized using the BHUVAN (Indian earth observation visualization) and Google Earth® from 2011 to 2013. Secondly, a total of 14 lan...

In the mid-ninth century, an earthquake triggered a landslide that blocked the narrow gorge of the Jhelum River where it exits the Kashmir Valley. The landslide impounded a lake that extended ≈100 km along the floor of the valley, implying an impounded volume of ≤21 km 3 , flooding the capital, Srinagar, and much agricultural land. An engineered breach of the landslide was contrived by a Medieval engineer resulting in the catastrophic release of flood waters. Using reasonable assumptions we calculate the probable minimum drainage time of this Medieval flood (<4 days) and maximum downstream surge velocities (≈12 m/s). These would have been sufficient to transport boulders in the bed of the Jhelum with dimensions of ≈6 m, consistent with those currently present in some reaches of the river. Given the morphology of the Jhelum gorge we consider that landslide outburst floods may have been common in Kashmir's history. Ancient shorelines indicate that paleo-lake volumes in the Kashmir Valley may have exceeded 400 km 3 which, were they released in catastrophic floods, would have been associated with potential downstream outburst velocities >32 m/s, able to transport boulders with dimensions ≈40 m, far in excess of any found in the course of the Jhelum or in the Punjab plains. Their absence suggests that Kashmir's ancient lakes were not lowered by outburst mechanisms much exceeding those associated with Suyya's flood. Present-day floods have been many tens of meters shallower than those impounded by landslides in the Jhelum in the past several thousands of years. A challenge for future study will be to date Kashmir's ancient shorelines to learn how often landslides and major impoundment events may have occurred in the valley.