Landslide Hazard Zonation

Landslides are a significant hazard in Churachandpur district, Manipur, frequently triggered by heavy rainfall, earthquakes and human activities such as deforestation, shifting cultivation and constructions. The landslides are more prominent along national highway 150 and 102B due to high topography, ranging up to 2,100 metres above sea level. The research used weighted parameter analysis, Remote Sensing (RS) and Geographic Information System (GIS) methodologies to create
a landslide susceptibility map for the study area. High-resolution thematic layers were generated from various data sources, including terrain-corrected data from earthexplorer.usgs.gov (SRTM 30
m resolution), Sentinel-2A multi-spectral satellite imagery (10 m resolution) and LANDSAT 8 satellite data, alongside other relevant factors such as rainfall distribution, slope and structural features
(faults, drainage density, roads).
These thematic layers were integrated within a GIS platform (ArcGIS 10.8) to identify zones vulnerable to landslides. A standard weighted overlay technique was employed to assign values ranging from 0 to 10 to different causative factors influencing landslide occurrence. The resulting landslide susceptibility map categorises the study area into three levels: high, medium and low susceptibility. The landslide displacement in high-susceptibility zones highlights significant terrain
movement, ranging from minor soil shifts to large-scale debris flow, disrupting transportation, damaging infrastructure and threatening livelihoods, requiring urgent mitigation measures for regional safety. This research provides valuable insights for regional infrastructure planning,
landslide hazard mitigation and geo-environmental development, ultimately contributing to enhanced safety and sustainable development in the Churachandpur district.
These vulnerable areas are located near major infrastructures and forest lands, so there is a need to have some kind of controls, such as slope stabilization, erosion control, and regulated deforestation, which will help to reduce the incidences of these occurrences. ROC curve analysis
model validation showed very good results (r = 0.89), demonstrating that there is a very good
correlation between the predicted and the observed at landslide event locations. This spatial strategy is an essential instrument for the disaster risk mitigation which is being used to direct the establishment of the sustainable development and resilience strategy in the landslide-prone
mountainous areas like Churachandpur.

Assessing landslide risk is a fundamental requirement to plan suitable prevention actions. To date, most risk studies focus on individual slopes or catchments. Whereas regional, national or continental scale assessments are hardly available because of methodological and/or data limitations. In this contribution, we present an overview of all requirements and limitations in landslide risk studies across all spatial scales, by means of a hybrid form that combines elements of original research with the comprehensive characteristics of a review study. The review critically analyses each component in the landslide risk analysis providing a detailed explanation of their state-of-the-art, with dedicated sections on susceptibility, hazard, exposure, and vulnerability. To put the theoretical framework to test, we also dive into a case study, expressed at the continental scale. Specifically, we take the main European mountain ranges and provide the reader with a textbook example of risk assessment for such a large territory. In doing so, we take into account issues associated with cross-national differences in landslide mapping. As a result, we identify landslide-prone European landscape and explore the associated possible economic consequences (human settlements and agricultural areas). We also analyze the population at risk during daytime and nighttime. Moreover, a modern view of the problem is explored in the form of how risk outcomes should be delivered to master planners and geoscientific personnel alike. Specifically, we convert our output into an interactive Web Application (https://pan-european-landslide-risk.github.io/) to include notions of scientific communication both to a large public as well as to a technical audience.

Steep slope, steep dips of the lithotypes, presence of clay layering in weathered rock types, events of continuous heavy rains, flooding on the slopes and improper land use practices play a major role in the genesis of landslides in the Nilgiris. Recent enhancement in the events of the landslides in the Nilgiris is mainly due to ongoing Seismotectonic activities in Southern Granulite Terrain (SGT) of South India and reactivation of hidden blind shear zones of Nilgiri Hills. Mitigation measures are highlighted.

Out of 25 administrative districts in Sri Lanka ten (10) districts are prone to landslides. These landslide prone areas cover approximately 30% of the total land area of the island, and it is occupied by about 35% of the population of Sri Lanka. Landslide density is occurring in these districts are at 1-2 per sq.km. After a landslide disaster, in situ adaptation on reconstruction in the same location is not possible in most of the cases. Therefore, relevancy of resettlement is needed as a post disaster recovery and reconstruction option. Moreover, after a landslide disaster, another unstable slope could be created within the surrounding areas with the effect of initial failure. As a result, a resettlement program has to act as a recovery and preventive strategy, in order to recover the affected parties and protect the vulnerable communities living in risk areas. In the process of resettlement and expansion of development activities, identifying suitable locations have become crucial factor for the success of the resettlement and development programs. A methodology to identify developable lands was developed based on the Landslide Hazard Zonation Map developed by NBRO. Outputs of the series of sensitivity analysis (hydrological, environmental, human settlement, slope analysis and flow path analysis) and spatial planning guidelines were incorporated to the methodology using sieve map techniques in GIS. Finally, this study enables the identification of potential lands for development and resettlement under eight categories based on existing landslide hazard and accessibility to services. Further, methodology will help development planning decision makers to adhere the conceptual development framework in landslide prone districts and to reduce landslide risk on future development activities.

— Landslide is routine geological process on earth’s crust, but recorded under disasters due to loss of lives and property. Prevention and mitigation of disaster can be planned if detected prior to the occurrence. The proposed paper is detection and mapping tool of probable mass movements and its destruction potential. The area surrounded by pre occurred landslide at Bhilar in Maharashtra is chosen for the present study. The effort has been made to study the Geo-informatics approach containing Remote sensing data and GIS as software integrated tool towards Landslide Hazard zonation. The various Spectral signatures and the image interpretation keys with respect to slope instability and various image data to identify Pre-occurred events and vulnerable sites are studied and used. The multivariate statistical analysis in the form of Information value method has been implemented along with the spatial analysis to obtain Landslide Susceptibility and Hazard Zonation. The methodology consid...

Abstract- Urban expansion has been creating an alarming situation in all countries of the world. High rate of urban population growth has led to serious land use problems such as loss of agricultural land, unauthorized urban sprawl, high land values, pollution, poverty and social unrest making urban governance a difficult task to maintain healthy urban environment. In the emerging scenario it is essential to have up-to-date information in existing land use information system. In the recent times, remote sensing and geographical information system (GIS) are very valuable and advantageous in providing current land use information. The present study highlights significance of remote sensing in the detection of urban land use changes for the time periods (1989 and 2006) using satellite imageries from IRS-P6, LISS III, IRS-P5, PAN and LANDSAT TM.. The satellite imageries IRS-P6, LISS III and IRS-P5, PAN for two consecutive dates were merged to produce a single merged image of two satelli...

ABSTRACT: The destructive seismic events of January 13 (ML: 7.6) and February 13 (ML: 6.1) 2001 in El Salvador, with origin in the subduction area and the volcanic chain, respectively, provide an ideal scenario to analyse the factors that define the landslide ...

Landslides are an example of severe natural disasters that occur worldwide and generate many harmful effects that can affect the stability and development of society. A better-quality susceptibility mapping technique for the landslide risk is crucial for mitigating landslides. However, the use of assemblages of multivariate statistical methods is still uncommon in Indonesia, particularly in the Kepahiang Regency of Bengkulu Province. Therefore, the objective of this study was to provide an improved framework for creating landslide susceptibility map (LSM) using multivariate statistical methods, i.e., the analytical hierarchy process (AHP) method, the simple additive weighting (SAW) method and the frequency ratio (FR) method. In this study, we established a landslide inventory considering 15 causative factors using the area under the curve (AUC) validation method and another evaluation technique. The performance of each causative factor was evaluated using multicollinearity and Pears...

In the present study landslide hazard zonation (LHZ) was carried out in an area around Alemketema town, central Ethiopia, about 120 km north of Addis Ababa. For LHZ map preparation, GIS based expert evaluation technique was followed. The parameters considered are; slope geometry, slope material, structural discontinuities, landuse and landcover, groundwater, seismicity, rainfall and manmade activities. For landslide hazard evaluation the study area was divided into 273 slope facets and thematic layers on slope facets and intrinsic parameters were prepared in GIS environment from secondary data, topographical map and satellite images. Later, primary data on various parameters was collected facet wise from the field and as per actual observations suitable modifications were made to the thematic maps. Further, geo-processing in GIS environment was done to know the type of parameter classes that fall within each slope facet. Based on the presence of various intrinsic and triggering parameters class within a slope facet, appropriate ratings were assigned to the parameters as per expert evaluation. Later, sum total of all ratings for various parameters form the basis to prepare the LHZ map in GIS. As per prepared LHZ map, 66.9% of the area falls into 'high hazard zone' and 33.1% falls into 'moderate hazard zone'. Validation of this LHZ map revealed that about 80% of past landslides fall within 'high hazard zone'. This reasonably confirms the rationality of adopted methodology, considered parameters and their evaluation in producing LHZ map.

Road transportation is the most common victim of landslide in the world. The present study investigates the landslide hazard zonation along the MH SH-73 at Kelghar ghat between Medha and Mahabaleshwar hill station of Maharashtra. Remote Sensing and GIS were used for the landslide hazard zonation of this section. The ghat section was buffered 100 m on both side to define the extent of study area based on the field investigation. The study incorporated predefined important landslide causative factors, viz. slope, rainfall, relief, lithology, soil depth, soil erosion, soil texture, land use / land cover, drainage distance, drainage density, lineament distance, lineament density, aspect, temperature, landslide inventory and in this approach fifteen thematic layers were prepared in GIS platform. The weight and score were assigned to each thematic layer based on heuristic approach on their relative importance in causing landslide. Multi-criteria model in ArcGIS 10.5 software were used for...

Slopes are the most common landforms in North Eastern Region (NER) of India and because of its relatively immature topography, active tectonics, and intense rainfall activities; the region is susceptible to landslide incidences. The scenario is further aggravated due to unscientific human activities leading to destabilization of slopes. Guwahati, the capital city of Assam also experiences similar hazardous situation especially during monsoon season thus demanding a systematic study towards landslide risk reduction. A systematic assessment of landslide hazard requires understanding of two components, "where" and "when" that landslides may occur. Presently no such system exists for Guwahati city due to lack of landslide inventory data, high resolution thematic maps, DEM, sparse rain gauge network, etc. The present study elucidates the potential of space-based inputs in addressing the problem in absence of field-based observing networks. First, Landslide susceptibility map in 1:10,000 scale was derived by integrating geospatial datasets interpreted from high resolution satellite data. Secondly, the rainfall threshold for dynamic triggering of landslide was estimated using rainfall estimates from Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis. The 3B41RT data for 1 hourly rainfall estimates were used to make Intensity-Duration plot. Critical rainfall was estimated for every incidence by analysing cumulative rainfall leading to a landslide for total of 19 incidences and an empirical rainfall intensity-duration threshold for triggering shallow debris slides was developed (Intensity = 5.9 Duration-0.479).

On Tuesday afternoon, 12 January 2010 at 16:53 local time, Haiti faced the most disastrous earthquake in its history since the 1842 Cap-Haïtien (north coast of Haiti) Earthquake. Occurred with a moment magnitude (M w) of 7.0, the 2010 Haiti earthquake devastated Port-au-Prince, Léogâne, and Jacmel. Despite some progress in rebuilding infrastructure, the high cost of living due, in particular, to political instability and unemployment forces people to rebuild in worse condition than before the 2010 earthquake. Based on an independent investigation and experience of the country's reality in the domain of construction, this paper highlights the main causes of the 2010 Haiti earthquake to alert the need for better rebuilding the country. Therefore, some suggestions are given to boost the construction practice in Haiti to circumvent the loss of life and property in future catastrophic events notably earthquakes.

Balia Nala is the outlet of the Nainital lake, flowing towards southeast direction. Presence of Nainital habitation at its right bank has high socioeconomic importance. This study presents the stability analysis of a ravine/valley along Balia Nala. Variegated slates (lower Krol and upper Blaini formations) are the main rock types, wherever the outcrop does exist and rest of the area is covered by slope wash and river borne materials. Three sets of joints are presented in the area, but 4 sets of joints also exist at some locations. Nainital lake fault intersected by Manora fault from southwest direction passes through eastern side of the study area, and some small faults, which are sub-branches of Nainital lake fault, are observed (with 10 m offset) and promote the landslide in the area. This study shows that different kinds of discontinuities (joints, faults and shear zones) and rapid down cutting by the stream due to neotectonic activity affect the stability of the slope. The fragile lithology and deep V-shaped valley further accelerate the mass movement in the study area. In addition, rock mass rating (RMR), factor of safety (FOS) and graphical analysis of the joints indicate the study area as landslide-prone zone. This study will be helpful in not only reducing the risk on life of people, but also in assisting the ongoing civil work in the study area.

BACKGROUND Recent landslide events such as the event in the Italian region Massa (Tuscany) at end of October 2010 (with two fatalities), or events in Styria, Austria (Feldbach June 2009, Gasen/Haslau August 2005) demonstrate that landslides can cause fatalities as well as high economic losses. Often, these events are not purely of scientific interest. Also responsible institutions recognise that the focus on remedial work is not sufficient, rather some information for preparedness in terms of spatial planning is beneficial as decision support for future developments. This has also been recognised in Austria by the state of Lower Austria. Within the area of their responsibility, approximate 2,000 entries in the "building ground register" of the Geological Survey of Lower Austria indicate that about fifty percent of the municipalities are affected by landslides. Hereby, landslide types range from rock fall to shallow translational and deep seated rotational slides. This number of events and afflicted municipalities emphasise the need of prevention measures on a regional scale in order to minimize the landslide hazards for inhabitants and their living environment. Powerful tools for enhancing spatial preparedness are landslide susceptibility maps, which can be implemented in spatial planning processes such as the "area zoning plans" of municipalities. Methods for landslide susceptibility modelling form a comprehensive research field which mainly covers the development of proper modelling methods, datasets and validation techniques in order to obtain reliable landslide susceptibility maps. However the implementation of the resulting maps in regional or local spatial planning is often missing because both modelling processes on regional scale and implementation of these maps into practise are challenging tasks for geoscientists as well as for spatial planners. Additionally the limited availability of appropriate spatial and temporal data on landslide events and explanatory parameters is a major restricting factor when performing modelling on regional scales. The research project MoNOE (Method development for landslide susceptibility modelling in Lower Austria) has been designed to address this gap and to develop proper methods of modelling and mapdesign. One major focus is to produce susceptibility maps which are end-user optimized and userfriendly arranged to be ready for implementation in spatial planning. The project is funded by the Geological Survey and the Department of Spatial Planning and Regional Policy of the Federal State Government of Lower Austria.

Background: Indonesia is one of the most earthquake prone countries in the world. More than 14,000 earthquakes of magnitude greater than 5 occurred in Indonesia between 1897 and 2009. Earthquakes are a major cause of slope instability eventually triggering coseismic landslides, which cost 1.5 million US$/ year in Java: one of the most densely islands in Indonesia. This paper aims to assess coseismic landslide susceptibility using Geographic Information System (GIS) on the western flank of Baturagung Escarpment, 8 km southeast of the Yogyakarta City, a data sparse area. Therefore, we have used a probabilistic seismic hazard analysis to calculate the peak ground accelerations, while the coseismic landslide susceptibility analysis was done by the scoring method in the GIS adopted from Mora and Vahrson model (Costa Rica), which is well adopted for data sparse areas. Results: The west flank of Baturagung Escarpment is dominated by moderate level of coseismic landslide with an average Coseismic Landslide Susceptibility Level (CLSL) of 33-162. The upper slope of Baturagung Escarpment, which consists of Semilir Formation has the CLSL of 163-512, corresponding to medium level CLSL (Mora and Vahrson model). The low level CLSL is mainly located on the foot slopes of Baturagung Escarpment, while the alluvial and colluvial plains located along the Opak River have very low CLSL (0-6). Conclusions: Based on the mapped landslide occurrence, the landslides tend to occur in the zone of moderate CLSL and they are distributed along the border between moderate and low coseismic landslide zone, meaning that the change on local condition could be playing an important role in triggering coseismic landslide.

Although anecdotal evidence suggests that there is a strong link between shelter activities and the improvement of non-house related social conditions of beneficiaries, rigorous studies assessing this link are still very limited and not available in the case of Haiti. Furthermore, rigorous evidence-based guidance for the decision makers (government and international partners) on the most effective resource allocation in the shelter sector is still missing. Shepper and Hill (2005) in “The Economic Impact of Shelter Assistance in Post-Disaster Settings”, provide one of the few available studies that looks into the impact of emergency shelter programs in the development of post-relief economies, building incomes of the affected populations and taking the first steps towards rigorous measurement of the impact of these programs on the incomes of the beneficiaries. The authors find that investments in emergency shelter provision offer significant returns, generating payback valued at thre...

Landslides threaten most parts of the provincial state of Lower Austria and cause damage to agricultural land, forests, infrastructure, settlements and people. Thus, the project "MoNOE" (Method development for landslide susceptibility modelling in Lower Austria) was initiated by the provincial government to tackle these problems and to reduce further damage by landslides. The main aim is to prepare landslide susceptibility maps for slides and rock falls and to implement these maps into the spatial planning strategies of the provincial state. Landslide susceptibility maps are either prepared by statistical (for slides) or empirical or process-based (for rock falls) approaches. Final maps are combined to a single landslide susceptibility map and optimised for the end-users (spatial planners and local authorities). It shows that a difference exists between the best scientific maps and the best maps for spatial planning purposes. This involves questions about the best number of susceptibility classes, its thresholds and ideal colours.

Landslide disaster risk reduction is presently a challenging task facing by Sri Lankan geologists. Increasing trend of population growth in Sri Lanka has adversely affected the stability of central highland due to various human activities. Among them establishment of human settlements and change in land use pattern have become a serious issue in triggering land instabilities in central highland of the country. National Building Research Oragnisation which is the main focal point in land slide disaster risk reduction in Sri Lanka has taken valuable and timely needed actions including preparation of landslide hazard zonation maps, early warnings and mitigations. Though the landslide is a geological phenomenon, it is highly interacted with human societies. Hence managing the issues arising with the landslide occurrence should be addressed with a sociological approach. This new approach is known as Socio Geological approach which is discussed here. Key words: Landslide, Geology, Socio G...

Background: Indonesia is one of the most earthquake prone countries in the world. More than 14,000 earthquakes of magnitude greater than 5 occurred in Indonesia between 1897 and 2009. Earthquakes are a major cause of slope instability eventually triggering coseismic landslides, which cost 1.5 million US$/ year in Java: one of the most densely islands in Indonesia. This paper aims to assess coseismic landslide susceptibility using Geographic Information System (GIS) on the western flank of Baturagung Escarpment, 8 km southeast of the Yogyakarta City, a data sparse area. Therefore, we have used a probabilistic seismic hazard analysis to calculate the peak ground accelerations, while the coseismic landslide susceptibility analysis was done by the scoring method in the GIS adopted from Mora and Vahrson model (Costa Rica), which is well adopted for data sparse areas. Results: The west flank of Baturagung Escarpment is dominated by moderate level of coseismic landslide with an average Coseismic Landslide Susceptibility Level (CLSL) of 33-162. The upper slope of Baturagung Escarpment, which consists of Semilir Formation has the CLSL of 163-512, corresponding to medium level CLSL (Mora and Vahrson model). The low level CLSL is mainly located on the foot slopes of Baturagung Escarpment, while the alluvial and colluvial plains located along the Opak River have very low CLSL (0-6). Conclusions: Based on the mapped landslide occurrence, the landslides tend to occur in the zone of moderate CLSL and they are distributed along the border between moderate and low coseismic landslide zone, meaning that the change on local condition could be playing an important role in triggering coseismic landslide.

Background: Indonesia is one of the most earthquake prone countries in the world. More than 14,000 earthquakes of magnitude greater than 5 occurred in Indonesia between 1897 and 2009. Earthquakes are a major cause of slope instability eventually triggering coseismic landslides, which cost 1.5 million US$/ year in Java: one of the most densely islands in Indonesia. This paper aims to assess coseismic landslide susceptibility using Geographic Information System (GIS) on the western flank of Baturagung Escarpment, 8 km southeast of the Yogyakarta City, a data sparse area. Therefore, we have used a probabilistic seismic hazard analysis to calculate the peak ground accelerations, while the coseismic landslide susceptibility analysis was done by the scoring method in the GIS adopted from Mora and Vahrson model (Costa Rica), which is well adopted for data sparse areas. Results: The west flank of Baturagung Escarpment is dominated by moderate level of coseismic landslide with an average Coseismic Landslide Susceptibility Level (CLSL) of 33-162. The upper slope of Baturagung Escarpment, which consists of Semilir Formation has the CLSL of 163-512, corresponding to medium level CLSL (Mora and Vahrson model). The low level CLSL is mainly located on the foot slopes of Baturagung Escarpment, while the alluvial and colluvial plains located along the Opak River have very low CLSL (0-6). Conclusions: Based on the mapped landslide occurrence, the landslides tend to occur in the zone of moderate CLSL and they are distributed along the border between moderate and low coseismic landslide zone, meaning that the change on local condition could be playing an important role in triggering coseismic landslide.

Background: Indonesia is one of the most earthquake prone countries in the world. More than 14,000 earthquakes of magnitude greater than 5 occurred in Indonesia between 1897 and 2009. Earthquakes are a major cause of slope instability eventually triggering coseismic landslides, which cost 1.5 million US$/ year in Java: one of the most densely islands in Indonesia. This paper aims to assess coseismic landslide susceptibility using Geographic Information System (GIS) on the western flank of Baturagung Escarpment, 8 km southeast of the Yogyakarta City, a data sparse area. Therefore, we have used a probabilistic seismic hazard analysis to calculate the peak ground accelerations, while the coseismic landslide susceptibility analysis was done by the scoring method in the GIS adopted from Mora and Vahrson model (Costa Rica), which is well adopted for data sparse areas. Results: The west flank of Baturagung Escarpment is dominated by moderate level of coseismic landslide with an average Coseismic Landslide Susceptibility Level (CLSL) of 33-162. The upper slope of Baturagung Escarpment, which consists of Semilir Formation has the CLSL of 163-512, corresponding to medium level CLSL (Mora and Vahrson model). The low level CLSL is mainly located on the foot slopes of Baturagung Escarpment, while the alluvial and colluvial plains located along the Opak River have very low CLSL (0-6). Conclusions: Based on the mapped landslide occurrence, the landslides tend to occur in the zone of moderate CLSL and they are distributed along the border between moderate and low coseismic landslide zone, meaning that the change on local condition could be playing an important role in triggering coseismic landslide.

Landslide susceptibility map delineates the potential zones for landslides occurrence. The paper presents anintegration approach through spatial data analysis in GIS for landslide susceptibility mapping in Kolli hill, Namakkal District, Tamil Nadu. Six important causative factors for landslide occurrences were selected and corresponding thematic data layers were prepared in GIS. Topographic maps, satellite image, field data and preparation of the following maps like Drainage, lineament, soil, geology, slope, land use/land cover. Numerical weights for different categories of these factors were determined based on the weighted thematic layers were integrated in GIS environment to generate the landslide susceptibility map of the area.The landslide susceptibility map classifies the area into five different landslide susceptible zones i.e., very high, high, moderate, low and very low. This map was validated using the existing landslide distribution in the area.

The purposes of this study are to extract lineaments from satellite images in order to contribute to the understanding of the faults. IRS-IC LISS-III geo coded image is used for the analysis which is processed by extraction of lineament and lineament density. The study of lineaments from remote sensed imagery offers an attractive alternative analysis technique. An effective approach for delineation of fracture zones is based on lineament indices extracted from satellite data. With a detailed structural analysis and understanding of the tectonic evolution of a given area it delivers useful evidence for geological mapping, groundwater flow and occurrence in fractured rocks. The accuracy analysis extracted lineaments and lineament density is determined from the high resolution satellite data and results in a higher quality of lineament and lineament density map.

An accurate method of generating landslide hazard zonation is very important to mitigate the loss of properties and lives
caused by this type of geological hazard. This paper presents the study of GIS based approach in parts of Kodaikanal Hills. The first
part of the methodology involves preparation of geology, geomorphic map, relative relief, drainage and landuse/landcover map. In
the second stage, to identify the Landslide hazard zonation areas, the above-mentioned parameters were analyzed in a GIS by
assigning appropriate ranks and weightages were assigned to prepare the landslide Hazard zonation map.

Landslide susceptibility modeling using neural network (ANN) are applied to semi detailed volcanic-sedimentary water catchment. Annually landslide occurred in catchment area frequently in unconsolidated and weathered material combined with uncertainty in rainfall pattern that complicated landslide occurrence. Data used for analysis including landslide inventory, geology, digital elevation related data, distance to stream, and several other available data. Results show that machine learning method yield fair result data based on evaluation on Area under Curve (AUC). Thus, it can be suggested that machine learning methods for landslide susceptibility model could still be develop to produce robust prediction model with different characterization of parameter data and machine learning parameters.

On 14th August 2021, a magnitude 7.2 earthquake struck the Tiburon Peninsula in the Caribbean nation of Haiti, approximately 150 km west of the capital Port-au-Prince. Aftershocks up to moment magnitude 5.7 followed and over 1,000 landslides were triggered. These events led to over 2,000 fatalities, 15,000 injuries and more than 137,000 structural failures. The economic impact is of the order of US$1.6 billion. The on-going Covid pandemic and a complex political and security situation in Haiti meant that deploying earthquake engineers from the UK to assess structural damage and identify lessons for future building construction was impractical. Instead, the Earthquake Engineering Field Investigation Team (EEFIT) carried out a hybrid mission, modelled on the previous EEFIT Aegean Mission of 2020. The objectives were: to use open-source information, particularly remote sensing data such as InSAR and Optical/Multispectral imagery, to characterise the earthquake and associated hazards; t...

Landslide Hazards Zonation Mapping is a major tool for the geographer, geologist, ground engineer, and land-use planner for landslide prevention strategies. The main outcome of the present study is to prepare a Landslide Hazards Zonation Map of the region along the North Sikkim Road Corridor in Sikkim Himalayas, an area highly vulnerable to the landslides. The initial step of this study is involved preparation of input raster layers of the landslide controlling factors. Seven controlling factors are selected for this purpose. These controlling factor-like slope, aspect, lithology, faults, river alignment, road network, and land-use are through Geographic Information System software using multi-criteria analysis. The Analytic Hierarchy Process is used to determine the weightage of the various causative factors. Weighted Overlay Method is used for the assignment of ranks and weights to each factor. The Landslide Hazard Zonation Index is then estimated with the help of a multi-criteria...

Background: Indonesia is one of the most earthquake prone countries in the world. More than 14,000 earthquakes of magnitude greater than 5 occurred in Indonesia between 1897 and 2009. Earthquakes are a major cause of slope instability eventually triggering coseismic landslides, which cost 1.5 million US$/ year in Java: one of the most densely islands in Indonesia. This paper aims to assess coseismic landslide susceptibility using Geographic Information System (GIS) on the western flank of Baturagung Escarpment, 8 km southeast of the Yogyakarta City, a data sparse area. Therefore, we have used a probabilistic seismic hazard analysis to calculate the peak ground accelerations, while the coseismic landslide susceptibility analysis was done by the scoring method in the GIS adopted from Mora and Vahrson model (Costa Rica), which is well adopted for data sparse areas. Results: The west flank of Baturagung Escarpment is dominated by moderate level of coseismic landslide with an average Coseismic Landslide Susceptibility Level (CLSL) of 33-162. The upper slope of Baturagung Escarpment, which consists of Semilir Formation has the CLSL of 163-512, corresponding to medium level CLSL (Mora and Vahrson model). The low level CLSL is mainly located on the foot slopes of Baturagung Escarpment, while the alluvial and colluvial plains located along the Opak River have very low CLSL (0-6). Conclusions: Based on the mapped landslide occurrence, the landslides tend to occur in the zone of moderate CLSL and they are distributed along the border between moderate and low coseismic landslide zone, meaning that the change on local condition could be playing an important role in triggering coseismic landslide.

Landslides are the downward movement of materials under the influence of gravity when shear stress exceeds the shear strength of the material. It includes various movements resulting in complex type of slope failures which commonly occurred on cut slopes of Ghat roads in mountaneous region. The study area chosen for the geotechnical investigation is Kolli hills situated in the tail end of the Eastern Ghats in Namakkal district of Tamil Nadu, India. The ghat road section of 20 km stretch along with 70 hairpin bends, connects the foothills at Karavallikkombai to Sholaikkadu at the top is selected for the present study. The hill is situated at a fault zone which is extended from Mettur dam, Salem district, Tamil Nadu. In this study, undisturbed soil samples were collected from 10 landslide locations and tested for its index and engineering properties. Based on the test results, static slope stability analysis using Modified Bishop method and dynamic slope stability analysis using Simplified Newmark method were carried out to find out factor of safety of the slopes which is used to derive the slope stability assessment of the study area. The landslide hazard zone assessment was carried out to identify the landslide prone areas.

Landslides are common along western slopes of Sahyadri ranges and isolated hills of coastal plains in Konkan region of Maharashtra. Numerous landslides with low magnitude is an important characteristic of slope failures in this region. Though the magnitude of landslides in this region is low, they result in huge losses in terms of property damage and even loss of lives especially those occur along major communication routes. Present paper deals with the spatial distribution of landslides in Raigad district, Maharashtra based on the historical landslide records and field investigations. The landslide occurrence and its relationship with the rainfall has been assessed to determine the role of rainfall, lithology and geomorphology in slope failures. The results of the study revealed that the concentration of landslides in Raigad district is observed in the south and southeastern hilly tracts of the district. It is observed that the landslide process in this study area is also influenced by geo-environmental factors such as slope, aspect, structure, drainage, roads etc.

Landslides commonly occurs in hilly areas and causes an enormous loss iof life and property every year. National highway-1D (NH-1D) is the only road link between the two districts (Kargil and Leh) of Ladakh region that connects these districts with Kashmir valley. The landslide failure record of the recent past along this sector of the highway is not available. The present study documents landslide susceptible zones and records occurrence of 60 landslides during the last 4 years showing an increasing trend in the occurrence of landslides over these years in this sector. The landslide susceptibility zonation map has been prepared based on the numerical rating of ten major factors viz. slope morphometry, lithology, structure, relative relief, land cover, landuse, rainfall, hydrological conditions, landslide incidences and Slope Erosion, categorised the area in different zones of instability based on the intensity of susceptibility. The landslide susceptibility map of the area encompassing 73.03 km 2 is divided into 150 facets. Out of the total of 150 facets, 85 facets fall in low susceptibility zone covering 43.56 km 2 which constitute about 59.65% of the total area under investigation with a record of 5 landslides; 40 facets fall in the moderate susceptibility zone covering 16.94km 2 which constitutes about 23.19% of the study area with a record of 20 landslides; and 25 facets fall in the high susceptibility zone covering 12.53 km 2 which constitute about 17.15% of the study area with a record of 35 landslides. Most of the facets which fall in HSZ are attributed to slope modification for road widening.

Landslides commonly occurs in hilly areas and causes an enormous loss iof life and property every year. National highway-1D (NH-1D) is the only road link between the two districts (Kargil and Leh) of Ladakh region that connects these districts with Kashmir valley. The landslide failure record of the recent past along this sector of the highway is not available. The present study documents landslide susceptible zones and records occurrence of 60 landslides during the last 4 years showing an increasing trend in the occurrence of landslides over these years in this sector. The landslide susceptibility zonation map has been prepared based on the numerical rating of ten major factors viz. slope morphometry, lithology, structure, relative relief, land cover, landuse, rainfall, hydrological conditions, landslide incidences and Slope Erosion, categorised the area in different zones of instability based on the intensity of susceptibility. The landslide susceptibility map of the area encompassing 73.03 km 2 is divided into 150 facets. Out of the total of 150 facets, 85 facets fall in low susceptibility zone covering 43.56 km 2 which constitute about 59.65% of the total area under investigation with a record of 5 landslides; 40 facets fall in the moderate susceptibility zone covering 16.94km 2 which constitutes about 23.19% of the study area with a record of 20 landslides; and 25 facets fall in the high susceptibility zone covering 12.53 km 2 which constitute about 17.15% of the study area with a record of 35 landslides. Most of the facets which fall in HSZ are attributed to slope modification for road widening.

In the present study landslide hazard zonation (LHZ) was carried out in an area around Alemketema town, central Ethiopia, about 120 km north of Addis Ababa. For LHZ map preparation, GIS based expert evaluation technique was followed. The parameters considered are; slope geometry, slope material, structural discontinuities, landuse and landcover, groundwater, seismicity, rainfall and manmade activities. For landslide hazard evaluation the study area was divided into 273 slope facets and thematic layers on slope facets and intrinsic parameters were prepared in GIS environment from secondary data, topographical map and satellite images. Later, primary data on various parameters was collected facet wise from the field and as per actual observations suitable modifications were made to the thematic maps. Further, geo-processing in GIS environment was done to know the type of parameter classes that fall within each slope facet. Based on the presence of various intrinsic and triggering parameters class within a slope facet, appropriate ratings were assigned to the parameters as per expert evaluation. Later, sum total of all ratings for various parameters form the basis to prepare the LHZ map in GIS. As per prepared LHZ map, 66.9% of the area falls into 'high hazard zone' and 33.1% falls into 'moderate hazard zone'. Validation of this LHZ map revealed that about 80% of past landslides fall within 'high hazard zone'. This reasonably confirms the rationality of adopted methodology, considered parameters and their evaluation in producing LHZ map.

The present study was carried out along the newly constructed road from Fofa town to Gilgel Gibe-II powerhouse in South western Ethiopia. In this study, an attempt has been made to provide information on the landslide hazard zones present along the new road. In order to delineate the hazardous zones the landslide hazard evaluation factor rating scheme (LHEF) proposed by Anbalagan (1992) has been utilized. The LHEF rating scheme is based on an empirical approach which combines past experience gained from the study of causative factors and their impact on landslides with conditions anticipated in the area of study. For LHEF rating scheme data on major inherent causative factors of slope instability such as geology, slope morphometry, relative relief, land use and land cover and ground water conditions has been collected. Based on the evaluation values, the slopes in the study area have been classified for landslide potential as; High Hazard, Moderate Hazard and Low Hazard. The results of the present study indicate that 54% of the slopes in the study area fall in High Hazard, 34% in the Moderate Hazard and 12% in the Low Hazard zones. Thus, the Landslide Hazard Zonation shows that chances of slope failures are high in the study area.

Slopes are the most common landforms in North Eastern Region (NER) of India and because of its relatively immature topography, active tectonics, and intense rainfall activities; the region is susceptible to landslide incidences. The scenario is further aggravated due to unscientific human activities leading to destabilization of slopes. Guwahati, the capital city of Assam also experiences similar hazardous situation especially during monsoon season thus demanding a systematic study towards landslide risk reduction. A systematic assessment of landslide hazard requires understanding of two components, "where" and "when" that landslides may occur. Presently no such system exists for Guwahati city due to lack of landslide inventory data, high resolution thematic maps, DEM, sparse rain gauge network, etc. The present study elucidates the potential of space-based inputs in addressing the problem in absence of field-based observing networks. First, Landslide susceptibility map in 1:10,000 scale was derived by integrating geospatial datasets interpreted from high resolution satellite data. Secondly, the rainfall threshold for dynamic triggering of landslide was estimated using rainfall estimates from Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis. The 3B41RT data for 1 hourly rainfall estimates were used to make Intensity-Duration plot. Critical rainfall was estimated for every incidence by analysing cumulative rainfall leading to a landslide for total of 19 incidences and an empirical rainfall intensity-duration threshold for triggering shallow debris slides was developed (Intensity = 5.9 Duration-0.479).

The present study area is located in Meta Robi District of West Showa Zone in Oromiya Regional State in Ethiopia. The main objective of the present study was to evaluate landslide hazard zonation (LHZ) by utilizing 'Grid overlay' and 'GIS modeling' approaches. Also, it was attempted to know the effectiveness of the two methods. The methodology followed was based on the analysis of past landslides in the area. For the present study six causative factors namely; slope material, slope, aspect, elevation, land use and land cover and groundwater surface traces were considered. Later, Landslide Susceptibility Index (LSI) was computed based on the relative influence of causative factors on past landslides. For the 'Grid overlay' method a grid with cells 10 m by 10 m was overlaid over the study area and later it was geo-processed to delineate various sub-classes of each causative factor. LSI values were assigned to each sub-causative factor within each grid cell and a 'Total Landslide Susceptibility Index' was calculated to produce the LHZ map. For 'GIS modeling' the same causative factors and similar LSI values were utilized. In the case of LHZ map prepared by the 'Grid overlay' method about 82% of past landslides fall within 'very high hazard' or 'high hazard' zones whereas in the case of 'GIS modeling' about 95% of past landslides fall within 'very high hazard' or 'high hazard' zones. Finally, the validation showed that 'GIS modeling' produced better LHZ map. Also, 'Grid overlay' method is more tedious and time consuming as compared to GIS modeling.

The landslides are one of the most important types of natural hazards. Large landslides create loss of both human life and property. However, people living in the mountainous regions are accustomed to live with them. With the increased tourism over the past few decades, residential areas have spread over mountainous slopes, which naturally require new communication system. This tampers the natural slopes and environment of the mountainous regions, thereby increasing susceptibility to landslides occurrence.

The Western Ghats, the bold westerly escarpment of India paralleling the west coast, are characterized by different geologic and geomorphic units formed during different episodes of Earth's history. The majority of these present day landforms evolved in response to the tectonic activity that the Western Ghats witnessed during the Tertiary period. The major structural features together with the geomorphic units have predominant role in the occurrence of cataclysmic landslides which the windward slope of Western Ghats witness during the peak monsoon season. The Kerala and Periyar lineaments, which are the sites of minor earthquakes, pass through the study area. Escarpments and structural hill systems are the vulnerable landforms for landslide occurrence. Due to the predominant role of these tectonic and geomorphic features in the capricious change of landforms, a study was carried out in this hilly terrain based on geomorphology. The study of soil, slope morphometry, relative relief, land use/land cover and hydrogeological conditions together with a multidimensional analysis in a GIS environment resulted in classifying the entire area into different landslide susceptible zones based on Bureau of Indian Standards. Moreover, the area is also divided into three zones based on the terrain conditions and the type of landslide occurrence. The methodology can well fit with any area experiencing the same terrain conditions and can be used to classify an area on the basis of landslide occurrence and geomorphology.

Como parte del proyecto:“Microzonificación de peligros geológicos e hidrometeorológicos para las zonas conurbadas de Orizaba, Veracruz, y las principales localidades ubicadas en las subcuencas bajas: La Antigua y Jamapa”, patrocinado porlos Fondos Mixtos CONACyT-Gobierno del Estado de Veracruz, dondese estudia de manera integral los peligros por fenómenos naturales en las subcuencas y sus principales áreas urbanas, se presentan los resultados preliminares obtenidos de la evaluación de susceptibilidad al deslizamiento de laderas en las cuencas Jamapa y La Antigua.

            En la evaluación se empleó el método Mora-Vahrson (Mora et. al., 1992) para establecer,de manera aproximada, los sectores con potencial a presentar deslizamientos por la combinación de los factores de disparo: lluvia y sismo. Para llevar a cabo lo anterior se utilizó diversa información cartográfica publicada por INEGI: geología, litología, humedad y lluvia, a escala 1:250,000. Los mapas de pendientes fueron obtenidos a partir de los modelos digitales de elevación del terreno disponibles en la herramienta CEM3.0 (INEGI, 2016), con una resolución de pixel de 15 x 15 metros.

            Los resultados se presentan a través de mapas que muestran zonas con diferentes grados de susceptibilidad al deslizamiento, siendo el objetivo general del estudio establecer las políticas públicas de mitigación de riesgo, regulando de manera adecuada el uso de suelo y de los recursos naturales en zonas conurbadas que se vean afectadas por este tipo de fenómenos geológicos, dentro del área de estudio, estableciendo un escenario que muestre la amenaza por deslizamiento con fines de prevención

Balia Nala is the outlet of the Nainital lake, flowing towards southeast direction. Presence of Nainital habitation at its right bank has high socioeconomic importance. This study presents the stability analysis of a ravine/valley along Balia Nala. Variegated slates (lower Krol and upper Blaini formations) are the main rock types, wherever the outcrop does exist and rest of the area is covered by slope wash and river borne materials. Three sets of joints are presented in the area, but 4 sets of joints also exist at some locations. Nainital lake fault intersected by Manora fault from southwest direction passes through eastern side of the study area, and some small faults, which are sub-branches of Nainital lake fault, are observed (with 10 m offset) and promote the landslide in the area. This study shows that different kinds of discontinuities (joints, faults and shear zones) and rapid down cutting by the stream due to neotectonic activity affect the stability of the slope. The fragile lithology and deep V-shaped valley further accelerate the mass movement in the study area. In addition, rock mass rating (RMR), factor of safety (FOS) and graphical analysis of the joints indicate the study area as landslide-prone zone. This study will be helpful in not only reducing the risk on life of people, but also in assisting the ongoing civil work in the study area.

Java, the most densely populated island in Indonesia, is located on top of the most seismically active areas in Southeast Asia: the Sunda Megathrust. This area is frequently hit by strong earthquake. More than 3,300 M>5earthquakesoccurred between 1973-2014. The wide range of mountainous areas and high intensity of rainfall, make several part of the island one of the most exposed regions for coseismic landslides such as Baturagung area, the Southeast mountainous area of Yogyakarta Province. An integrated method between RS and GIS was used to conduct the vulnerability assessment due to the lack of the site specific slope instability analysis and coseismic landslides data. The seismic zonation of Baturagung area was obtained based on the analysis of Kanai attenuation. The geologic information was extracted using remote sensing interpretation based on the 1:100,000 geologic map of Yogyakarta and geomorphologic map of Baturagung area as well. The coseismic landslide hazard assessment ...

Landslide is a significant natural hazard in mountainous terrain countries all around the world. Such disasters cause for the loss of hundreds of millions of dollars and thousands of death to all record each year. Scientific studies will help to minimize risks posed by sudden landslide hazard occurring in different corners of the world. The objective of this review focus on the study of methodologies used in previous research articles related to landslide hazard zonation. Geological maps were used as a source for lithology, soil and land use was processed from Landsat +ETM satellite. Slope and elevation were derived from Digital Elevation Model (DEM) collected from ASTER satellite. LHZ maps were generated using a raster calculation. Results categorize study areas into four compartments, based on their raster calculation processed using GIS environment. 30% of study areas under the review articles were found a no hazard area and only 21% were considered as high hazard.

Abstract- Urban expansion has been creating an alarming situation in all countries of the world. High rate of urban population growth has led to serious land use problems such as loss of agricultural land, unauthorized urban sprawl, high land values, pollution, poverty and social unrest making urban governance a difficult task to maintain healthy urban environment. In the emerging scenario it is essential to have up-to-date information in existing land use information system. In the recent times, remote sensing and geographical information system (GIS) are very valuable and advantageous in providing current land use information. The present study highlights significance of remote sensing in the detection of urban land use changes for the time periods (1989 and 2006) using satellite imageries from IRS-P6, LISS III, IRS-P5, PAN and LANDSAT TM.. The satellite imageries IRS-P6, LISS III and IRS-P5, PAN for two consecutive dates were merged to produce a single merged image of two satelli...

Java, the most densely populated island in Indonesia, is located on top of the most seismically active areas in Southeast Asia: the Sunda Megathrust. This area is frequently hit by strong earthquake. More than 3,300 M>5earthquakesoccurred between 1973-2014. The wide range of mountainous areas and high intensity of rainfall, make several part of the island one of the most exposed regions for coseismic landslides such as Baturagung area, the Southeast mountainous area of Yogyakarta Province. An integrated method between RS and GIS was used to conduct the vulnerability assessment due to the lack of the site specific slope instability analysis and coseismic landslides data. The seismic zonation of Baturagung area was obtained based on the analysis of Kanai attenuation. The geologic information was extracted using remote sensing interpretation based on the 1:100,000 geologic map of Yogyakarta and geomorphologic map of Baturagung area as well. The coseismic landslide hazard assessment ...

Java, the most densely populated island in Indonesia, is located on top of the most seismically active areas in Southeast Asia: the Sunda Megathrust. This area is frequently hit by strong earthquake. More than 3,300 M>5earthquakesoccurred between 1973-2014. The wide range of mountainous areas and high intensity of rainfall, make several part of the island one of the most exposed regions for coseismic landslides such as Baturagung area, the Southeast mountainous area of Yogyakarta Province. An integrated method between RS and GIS was used to conduct the vulnerability assessment due to the lack of the site specific slope instability analysis and coseismic landslides data. The seismic zonation of Baturagung area was obtained based on the analysis of Kanai attenuation. The geologic information was extracted using remote sensing interpretation based on the 1:100,000 geologic map of Yogyakarta and geomorphologic map of Baturagung area as well. The coseismic landslide hazard assessment ...

Background: Indonesia is one of the most earthquake prone countries in the world. More than 14,000 earthquakes of magnitude greater than 5 occurred in Indonesia between 1897 and 2009. Earthquakes are a major cause of slope instability eventually triggering coseismic landslides, which cost 1.5 million US$/ year in Java: one of the most densely islands in Indonesia. This paper aims to assess coseismic landslide susceptibility using Geographic Information System (GIS) on the western flank of Baturagung Escarpment, 8 km southeast of the Yogyakarta City, a data sparse area. Therefore, we have used a probabilistic seismic hazard analysis to calculate the peak ground accelerations, while the coseismic landslide susceptibility analysis was done by the scoring method in the GIS adopted from Mora and Vahrson model (Costa Rica), which is well adopted for data sparse areas. Results: The west flank of Baturagung Escarpment is dominated by moderate level of coseismic landslide with an average Coseismic Landslide Susceptibility Level (CLSL) of 33-162. The upper slope of Baturagung Escarpment, which consists of Semilir Formation has the CLSL of 163-512, corresponding to medium level CLSL (Mora and Vahrson model). The low level CLSL is mainly located on the foot slopes of Baturagung Escarpment, while the alluvial and colluvial plains located along the Opak River have very low CLSL (0-6). Conclusions: Based on the mapped landslide occurrence, the landslides tend to occur in the zone of moderate CLSL and they are distributed along the border between moderate and low coseismic landslide zone, meaning that the change on local condition could be playing an important role in triggering coseismic landslide.