Geo-spatial Technology for Landslide Hazard Zonation and Prediction

Similar to other geo hazards, landslides cannot be avoided in mountainous terrain. It is the most common natural hazard in the mountain regions and can result in enormous damage to both property and life every year. Better understanding of the hazard will help people to live in harmony with the pristine nature. Since India has 15% of its land area prone to landslides, preparation of landslide susceptibility zonation (LSZ) maps for these areas is of utmost importance. These susceptibility zonation maps will give the areas that are prone to landslides and the safe areas, which in-turn help the administrators for safer planning and future development activities. There are various methods for the preparation of LSZ maps such as based on Fuzzy logic, Artificial Neural Network, Discriminant Analysis, Direct Mapping, Regression Analysis, Neuro-Fuzzy approach and other techniques. These different approaches apply different rating system and the weights, which are area and factors dependent. Therefore, these weights and ratings play a vital role in the preparation of susceptibility maps using any of the approach. However, one technique that gives very high accuracy in certain might not be applicable to other parts of the world due to change in various factors, weights and ratings. Hence, only one method cannot be suggested to be applied in any other terrain. Therefore, an understanding of these approaches, factors and weights needs to be enhanced so that their execution in Geographic Information System (GIS) environment could give better results and yield actual ground like scenarios for landslide susceptibility mapping. Hence, the available and applicable approaches are discussed in this chapter along with detailed account of the literature survey in the areas of LSZ mapping. Also a case study of Garhwal area where Support Vector Machine (SVM) technique is used for preparing LSZ is also given. These LSZ maps will also be an important input for preparing the risk assessment of LSZ

Integrating expert knowledge with statistical analysis for landslide susceptibility assessment at regional scale

Abstract: In this paper, an integration landslide susceptibility model by combining expert-based and bivariate statistical analysis (Landslide Susceptibility Index—LSI) approaches is presented. Factors related with the occurrence of landslides—such as elevation, slope angle, slope aspect, lithology, land cover, Mean Annual Precipitation (MAP) and Peak Ground Acceleration (PGA)—were analyzed within a GIS environment. This integrated model produced a landslide susceptibility map which categorized the study area according to the probability level of landslide occurrence. The accuracy of the final map was evaluated by Receiver Operating Characteristics (ROC) analysis depending on an independent (validation) dataset of landslide events. The prediction ability was found to be 76% revealing that the integration of statistical analysis with human expertise can provide an acceptable landslide susceptibility assessment at regional scale

Gis-Based Approaches To Slope Stability Analysis And Earthquake -Induced Landslide Hazard Zonation

Thesis (Ph.D.) University of Alaska Fairbanks, 2006This dissertation presents newly developed GIS-based deterministic and probabilistic approaches for slope stability analysis and earthquake-induced landslide hazard zonation. The described approaches combine numerical slope stability analysis with GIS spatial analysis to evaluate earthquake-induced slope failures, both shallow and deep-seated. The study has four major research components. The first component is a GIS-based procedure which was developed based on one-, two-, and three-dimensional (1D, 2D, and 3D) deterministic approaches to slope stability analysis and landslide hazard zonation. Slope stability methods in the GIS-based procedure included the infinite slope model, the block sliding model, the ordinary method of slices, the Bishop simplified method, and the Hovland's column method. The second component focuses on causative factors analysis of earthquake-induced landslide hazards. This component also discusses the determination of peak ground acceleration for slope stability analysis. The third component consists of an evaluation of the topographic effect of ground motion and the seismic response in the Balsamo Ridge area in Nueva San Salvador. The fourth component is concerned with the regional and site-specific landslide hazard zonation, using newly developed models for landslide hazard assessment in Nueva San Salvador. The slope stability and landslide susceptibility were mapped in terms of slope stability index (factor of safety, critical acceleration, Newmark displacement, failure probability, and reliability index). The landslides triggered by an earthquake on January 13, 2001 in El Salvador provide a setting for the calibration of results from GIS-based approaches. The procedures developed in this research proved to be feasible and cost-effective for slope stability analysis and earthquake-induced landslide hazard zonation

Statistical and spatial analysis of landslide susceptibility maps with different classification systems

The final publication is available at Springer via http://dx.doi.org/10.1007/s12665-016-6124-1A landslide susceptibility map is an essential tool for land-use spatial planning and management in mountain areas. However, a classification system used for readability determines the final appearance of the map and may therefore influence the decision-making tasks adopted. The present paper addresses the spatial comparison and the accuracy assessment of some well-known classification methods applied to a susceptibility map that was based on a discriminant statistical model in an area in the Eastern Pyrenees. A number of statistical approaches (Spearman’s correlation, kappa index, factorial and cluster analyses and landslide density index) for map comparison were performed to quantify the information provided by the usual image analysis. The results showed the reliability and consistency of the kappa index against Spearman’s correlation as accuracy measures to assess the spatial agreement between maps. Inferential tests between unweighted and linear weighted kappa results showed that all the maps were more reliable in classifying areas of highest susceptibility and less reliable in classifying areas of low to moderate susceptibility. The spatial variability detected and quantified by factorial and cluster analyses showed that the maps classified by quantile and natural break methods were the closest whereas those classified by landslide percentage and equal interval methods displayed the greatest differences. The difference image analysis showed that the five classified maps only matched 9 % of the area. This area corresponded to the steeper slopes and the steeper watershed angle with forestless and sunny slopes at low altitudes. This means that the five maps coincide in identifying and classifying the most dangerous areas. The equal interval map overestimated the susceptibility of the study area, and the landslide percentage map was considered to be a very optimistic model. The spatial pattern of the quantile and natural break maps was very similar, but the latter was more consistent and predicted potential landslides more efficiently and reliably in the study area.Peer ReviewedPreprin

Morphological parameters causing landslides: A case study of elevation

The history of landslide susceptibility maps goes back about 50 years. Hazard and risk maps later followed these maps. Inventory maps provide the source of all these. There are different parameters selected specially for each field in the literature as well as parameters selected because they are easy to produce and obtain data. This study tried to research the effect of elevation on landslides by reviewing the literature in detail. The used class ranges and elevation values were reviewed and applied to map sections selected from Turkey. By analyzing the results, the goal was to determine at which elevation ranges landslides occurred. The study tried to investigate the effect of the parameter of elevation using data from the literature. It works to compare the elevation values for map sections selected to compare with the literature. The study comprises two stages. The first step tried to acquire statistical data by researching the data from the literature. The data were investigated in the second stage. For this purpose, close to 1.500 studies prepared between 1967 and 2019 were reviewed. According to the literature, the parameter of was used in analyses because it is easy to produce and is morphologically effective

Impact of DEM-derived factors and analytical hierarchy process on landslide susceptibility mapping in the region of Rożnów Lake, Poland

El artículo analiza las desigualdades que se gestan y reproducen en las trayectorias educativas universitarias de los jóvenes ecuatorianos en España y Ecuador en el contexto de la crisis, centrándose en las estrategias vinculadas a la movilidad de estos jóvenes y sus familias y el papel que juegan las políticas públicas. Se examinan los recorridos de tres grupos de universitarios: las hijas e hijos de la migración de los 2000, los retornados a Ecuador y los que llegan a España gracias a las ayudas del gobierno ecuatoriano para realizar postgrados. Se parte de una metodología fundamentalmente cualitativa basada en entrevistas, grupos de discusión y una encuesta a los participantes desde España de la prueba de acceso para integrarse en universidades públicas ecuatorianas. Los hallazgos ponen de relieve los capitales que manejan unos y otros y las restricciones sociales y económicas que encuentran. Mientras el primer grupo intenta mantenerse en la universidad, aun degradando sus expectativas, en el segundo grupo se advierte que la educación forma parte de en una estrategia más amplia que descansa en las redes transnacionales tejidas durante más de una década de migración hacia España. Finalmente, los del tercero han seguido trayectorias heterogéneas ascendentes que incluyen el desplazamiento.El artículo analiza las desigualdades que se gestan y reproducen en las trayectorias educativas universitarias de los jóvenes ecuatorianos en España y Ecuador en el contexto de la crisis, centrándose en las estrategias vinculadas a la movilidad de estos jóvenes y sus familias y el papel que juegan las políticas públicas. Se examinan los recorridos de tres grupos de universitarios: las hijas e hijos de la migración de los 2000, los retornados a Ecuador y los que llegan a España gracias a las ayudas del gobierno ecuatoriano para realizar postgrados. Se parte de una metodología fundamentalmente cualitativa basada en entrevistas, grupos de discusión y una encuesta a los participantes desde España de la prueba de acceso para integrarse en universidades públicas ecuatorianas. Los hallazgos ponen de relieve los capitales que manejan unos y otros y las restricciones sociales y económicas que encuentran. Mientras el primer grupo intenta mantenerse en la universidad, aun degradando sus expectativas, en el segundo grupo se advierte que la educación forma parte de en una estrategia más amplia que descansa en las redes transnacionales tejidas durante más de una década de migración hacia España. Finalmente, los del tercero han seguido trayectorias heterogéneas ascendentes que incluyen el desplazamiento.El artículo analiza las desigualdades que se gestan y reproducen en las trayectorias educativas universitarias de los jóvenes ecuatorianos en España y Ecuador en el contexto de la crisis, centrándose en las estrategias vinculadas a la movilidad de estos jóvenes y sus familias y el papel que juegan las políticas públicas. Se examinan los recorridos de tres grupos de universitarios: las hijas e hijos de la migración de los 2000, los retornados a Ecuador y los que llegan a España gracias a las ayudas del gobierno ecuatoriano para realizar postgrados. Se parte de una metodología fundamentalmente cualitativa basada en entrevistas, grupos de discusión y una encuesta a los participantes desde España de la prueba de acceso para integrarse en universidades públicas ecuatorianas. Los hallazgos ponen de relieve los capitales que manejan unos y otros y las restricciones sociales y económicas que encuentran. Mientras el primer grupo intenta mantenerse en la universidad, aun degradando sus expectativas, en el segundo grupo se advierte que la educación forma parte de en una estrategia más amplia que descansa en las redes transnacionales tejidas durante más de una década de migración hacia España. Finalmente, los del tercero han seguido trayectorias heterogéneas ascendentes que incluyen el desplazamiento.El artículo analiza las desigualdades que se gestan y reproducen en las trayectorias educativas universitarias de los jóvenes ecuatorianos en España y Ecuador en el contexto de la crisis, centrándose en las estrategias vinculadas a la movilidad de estos jóvenes y sus familias y el papel que juegan las políticas públicas. Se examinan los recorridos de tres grupos de universitarios: las hijas e hijos de la migración de los 2000, los retornados a Ecuador y los que llegan a España gracias a las ayudas del gobierno ecuatoriano para realizar postgrados. Se parte de una metodología fundamentalmente cualitativa basada en entrevistas, grupos de discusión y una encuesta a los participantes desde España de la prueba de acceso para integrarse en universidades públicas ecuatorianas. Los hallazgos ponen de relieve los capitales que manejan unos y otros y las restricciones sociales y económicas que encuentran. Mientras el primer grupo intenta mantenerse en la universidad, aun degradando sus expectativas, en el segundo grupo se advierte que la educación forma parte de en una estrategia más amplia que descansa en las redes transnacionales tejidas durante más de una década de migración hacia España. Finalmente, los del tercero han seguido trayectorias heterogéneas ascendentes que incluyen el desplazamiento.El artículo analiza las desigualdades que se gestan y reproducen en las trayectorias educativas universitarias de los jóvenes ecuatorianos en España y Ecuador en el contexto de la crisis, centrándose en las estrategias vinculadas a la movilidad de estos jóvenes y sus familias y el papel que juegan las políticas públicas. Se examinan los recorridos de tres grupos de universitarios: las hijas e hijos de la migración de los 2000, los retornados a Ecuador y los que llegan a España gracias a las ayudas del gobierno ecuatoriano para realizar postgrados. Se parte de una metodología fundamentalmente cualitativa basada en entrevistas, grupos de discusión y una encuesta a los participantes desde España de la prueba de acceso para integrarse en universidades públicas ecuatorianas. Los hallazgos ponen de relieve los capitales que manejan unos y otros y las restricciones sociales y económicas que encuentran. Mientras el primer grupo intenta mantenerse en la universidad, aun degradando sus expectativas, en el segundo grupo se advierte que la educación forma parte de en una estrategia más amplia que descansa en las redes transnacionales tejidas durante más de una década de migración hacia España. Finalmente, los del tercero han seguido trayectorias heterogéneas ascendentes que incluyen el desplazamiento.El artículo analiza las desigualdades que se gestan y reproducen en las trayectorias educativas universitarias de los jóvenes ecuatorianos en España y Ecuador en el contexto de la crisis, centrándose en las estrategias vinculadas a la movilidad de estos jóvenes y sus familias y el papel que juegan las políticas públicas. Se examinan los recorridos de tres grupos de universitarios: las hijas e hijos de la migración de los 2000, los retornados a Ecuador y los que llegan a España gracias a las ayudas del gobierno ecuatoriano para realizar postgrados. Se parte de una metodología fundamentalmente cualitativa basada en entrevistas, grupos de discusión y una encuesta a los participantes desde España de la prueba de acceso para integrarse en universidades públicas ecuatorianas. Los hallazgos ponen de relieve los capitales que manejan unos y otros y las restricciones sociales y económicas que encuentran. Mientras el primer grupo intenta mantenerse en la universidad, aun degradando sus expectativas, en el segundo grupo se advierte que la educación forma parte de en una estrategia más amplia que descansa en las redes transnacionales tejidas durante más de una década de migración hacia España. Finalmente, los del tercero han seguido trayectorias heterogéneas ascendentes que incluyen el desplazamiento.In the paper we analyze the inequalities that emerge from and are reproduced in Ecuadorian's higher education trajectories in the context of economic crises. We focus on the strategies that these youth and their families employ for social mobility as well as the role of public policy in these processes. We examine the trajectories of three groups: sons and daughters of the 2000 migration wave from Ecuador to Spain who study at universities in Spain, those who have returned to Ecuador for their studies, and Ecuadorians who move to Spain in order to carry out postgraduate studies, some of them funded by scholarships from the Ecuadorian government. The research project employed a qualitative methodology based on interviews, focus groups and a survey with Ecuadorians in Spain who took the entrance exam for admittance into Ecuador's public university system. Our findings highlight the varied forms of capitals that these diverse students employ, as well as the social and economic constraints that they encounter. In a period of economic crisis in Spain, the first group of students must often downgrade their expectations in order to continue their studies. Their experience contrasts starkly with Ecuadorians undertaking postgraduate studies in Spain, whose heterogenous trajectories are upwardly and geographically mobile. The case of the return university students to Ecuador shows us that education is inserted into a broader strategy that depends on transnational networks shaped over more than a decade of Ecuador-Spain migration

Análise multi-critério aplicada ao mapeamento da suscetibilidade a escorregamentos

This paper presents the application of a multi-criteria analysis (MCA) tool for landslide susceptibility assessment in Porto Alegre municipality, southern Brazil. A knowledge driven approach was used, aiming to ensure an optimal use of the available information. The landslide conditioning factors considered were slope, lithology, fl ow accumulation and distance from lineaments. Standardization of these factors was done through fuzzy membership functions, and evaluation of their relative importance for landslide predisposition was supported by the analytic hierarchy process (AHP), based on local expert knowledge. Finally, factors were integrated in a GIS environment using the weighted linear combination (WLC) method. For validation, an inventory, including 107 landslide points recorded between 2007 and 2013 was used. Results indicated that 8.2% (39.40 km²) of the study area are highly and very highly susceptible to landslides. An overall accuracy of 95% was found, with an area under the receiver operating characteristic (ROC) curve of 0.960. Therefore, the resulting map can be regarded as useful for monitoring landslide-prone areas. Based on the fi ndings, it is concluded that the proposed method is eff ective for susceptibility assessment since it yielded meaningful results and does not require extensive input data.Este estudo apresenta a aplicação de uma ferramenta de análise multi-critério para mapear a suscetibilidade a escorregamentos no município de Porto Alegre, sul do Brasil. Uma abordagem guiada pelo conhecimento de especialistas foi utilizada, com o intuito de otimizar a utilização das informações disponíveis. Os fatores condicionantes dos escorregamentos considerados foram declividade, litologia, acúmulo defl uxo e distância de lineamentos. A padronização desses fatores foi realizada por meio da aplicação de funções fuzzy e a importância relativa de cada um na predisposição do terreno a escorregamentos foi estabelecida com o apoio da técnica AHP (Analytic Hierarchy Process), com base no conhecimento de especialistas locais. Por fi m, a integração dos fatores em ambiente SIG se deu por meio do método denominado Combinação Linear Ponderada (WLC). Para validar os resultados, utilizou-se um mapa inventário contendo 107 cicatrizes de escorregamentos, registradas entre 2007 e 2013. Os resultados indicam que 8,2% (39,38 km²) da área de estudo possui uma suscetibilidade alta e muito alta a escorregamentos. A validação dos resultados obteve uma exatidão geral de 95%, com uma área abaixo da curva ROC (Receiver Operating Characteristic) de 0,960. Portanto, o mapa obtido pode ser considerado útil para monitorar as áreas propensas a esses processos. Com base nos resultados, conclui-se que o método proposto é efi caz para a avaliação da suscetibilidade, uma vez que os resultados obtidos são robustos e que não foi necessária uma quantidade extensa de dados de entrada

Intrinsic Environmental Vulnerability as Shallow Landslide Susceptibility in Environmental Impact Assessment

This work investigated the susceptibility factors that trigger shallow landslides. In particular, the objective of the research was the implementation of a method to determine the relevant factors that can trigger shallow landslide events. However, with respect to the existing methods, the integration with historical datasets and the inclusion of spatial factors displaying dynamics in the same characteristic timescales were specific features of the developed tool. The study area included the watersheds of the Sessera and Strona rivers in the alpine area of the Province of Biella (Piedmont, NW Italy). The method was developed and tested from two sub-datasets derived from an integrated dataset that referred to an intense event, involving the same area, that occurred in 1968 (2\u20133 November). This allowed the implementation of an integrated representation of landslides\u2019 predisposing factors and the identification and classification in dierent groups of the areas susceptible to geo-hydrological instability processes. The previously existing databases were verified and integrated into a geographic information system (GIS) environment, giving a potentially sharable source of information for planning purposes. The obtained maps represent a metric of one of the possible intrinsic environmental vulnerability factors for the area under study. Consequently, this method can represent a future instrument for determining the intrinsic environmental vulnerability dependent on landslides within an environmental impact assessment (EIA), as required by the most recent European regulation on EIA. Moreover, the shared information can be used to implement informed policy and planning processes, based on a bottom-up approach. In particular, the availability online of landslide susceptibility maps could support the generation of augmented information\u2014useful for both local administrators and planners as well as for stakeholders willing to implement specific projects or infrastructure in vulnerable areas, such as mountain