Information Value Model based Landslide Susceptibility Mapping at Phuentsholing, Bhutan

In the current study, statistical method of information value and geographic information system (GIS) were applied to develop Landslide Susceptibility Map (LSM) of Phuentsholing region, Bhutan. A total of 161 landslides, covering an area of 2.92 square kilometres were identified and 20% was randomly extracted for validation. Various factors causing landslide such as slope, aspect, elevation, proximity to road, drainage and fault, lithology, land use and normalised difference vegetation index (NDVI) were analysed to determine the contribution of each factors to the occurrence of a landslide. To evaluate the performance of the information value model in determining the LSM, overlay method and the Area under curve (AUC) of the receiver operating characteristic (ROC) were performed on the training and validation samples. The region was categorised mostly under high and moderate susceptibility, with land use, vegetation and elevation identified as most important contributing factors to landslide occurrences. The model has an AUC accuracy of 83.4% success rate and 83.5% prediction rate, with 77.5% of the validation samples lies under very high and high landslide susceptibility area when overlaid on the LSMIn the current study, statistical method of information value and geographic information system (GIS) were applied to develop Landslide Susceptibility Map (LSM) of Phuentsholing region, Bhutan. A total of 161 landslides, covering an area of 2.92 square kilometres were identified and 20% was randomly extracted for validation. Various factors causing landslide such as slope, aspect, elevation, proximity to road, drainage and fault, lithology, land use and normalised difference vegetation index (NDVI) were analysed to determine the contribution of each factors to the occurrence of a landslide. To evaluate the performance of the information value model in determining the LSM, overlay method and the Area under curve (AUC) of the receiver operating characteristic (ROC) were performed on the training and validation samples. The region was categorised mostly under high and moderate susceptibility, with land use, vegetation and elevation identified as most important contributing factors to landslide occurrences. The model has an AUC accuracy of 83.4% success rate and 83.5% prediction rate, with 77.5% of the validation samples lies under very high and high landslide susceptibility area when overlaid on the LSMIn the current study, statistical method of information value and geographic information system (GIS) were applied to develop Landslide Susceptibility Map (LSM) of Phuentsholing region, Bhutan. A total of 161 landslides, covering an area of 2.92 square kilometres were identified and 20% was randomly extracted for validation. Various factors causing landslide such as slope, aspect, elevation, proximity to road, drainage and fault, lithology, land use and normalised difference vegetation index (NDVI) were analysed to determine the contribution of each factors to the occurrence of a landslide. To evaluate the performance of the information value model in determining the LSM, overlay method and the Area under curve (AUC) of the receiver operating characteristic (ROC) were performed on the training and validation samples. The region was categorised mostly under high and moderate susceptibility, with land use, vegetation and elevation identified as most important contributing factors to landslide occurrences. The model has an AUC accuracy of 83.4% success rate and 83.5% prediction rate, with 77.5% of the validation samples lies under very high and high landslide susceptibility area when overlaid on the LS

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

Landslide Susceptibility Mapping Using Statistical Methods along the Asian Highway, Bhutan

In areas prone to frequent landslides, the use of landslide susceptibility maps can greatly aid in the decision-making process of the socio-economic development plans of the area. Landslide susceptibility maps are generally developed using statistical methods and geographic information systems. In the present study, landslide susceptibility along road corridors was considered, since the anthropogenic impacts along a road in a mountainous country remain uniform and are mainly due to road construction. Therefore, we generated landslide susceptibility maps along 80.9 km of the Asian Highway (AH48) in Bhutan using the information value, weight of evidence, and logistic regression methods. These methods have been used independently by some researchers to produce landslide susceptibility maps, but no comparative analysis of these methods with a focus on road corridors is available. The factors contributing to landslides considered in the study are land cover, lithology, elevation, proximity to roads, drainage, and fault lines, aspect, and slope angle. The validation of the method performance was carried out by using the area under the curve of the receiver operating characteristic on training and control samples. The area under the curve values of the control samples were 0.883, 0.882, and 0.88 for the information value, weight of evidence, and logistic regression models, respectively, which indicates that all models were capable of producing reliable landslide susceptibility maps. In addition, when overlaid on the generated landslide susceptibility maps, 89.3%, 85.6%, and 72.2% of the control landslide samples were found to be in higher-susceptibility areas for the information value, weight of evidence, and logistic regression methods, respectively. From these findings, we conclude that the information value method has a better predictive performance than the other methods used in the present study. The landslide susceptibility maps produced in the study could be useful to road engineers in planning landslide prevention and mitigation works along the highway

Training of Crisis Mappers and Map Production from Multi-sensor Data: Vernazza Case Study (Cinque Terre National Park, Italy)

This aim of paper is to presents the development of a multidisciplinary project carried out by the cooperation between Politecnico di Torino and ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The goal of the project was the training in geospatial data acquiring and processing for students attending Architecture and Engineering Courses, in order to start up a team of "volunteer mappers". Indeed, the project is aimed to document the environmental and built heritage subject to disaster; the purpose is to improve the capabilities of the actors involved in the activities connected in geospatial data collection, integration and sharing. The proposed area for testing the training activities is the Cinque Terre National Park, registered in the World Heritage List since 1997. The area was affected by flood on the 25th of October 2011. According to other international experiences, the group is expected to be active after emergencies in order to upgrade maps, using data acquired by typical geomatic methods and techniques such as terrestrial and aerial Lidar, close-range and aerial photogrammetry, topographic and GNSS instruments etc.; or by non conventional systems and instruments such us UAV, mobile mapping etc. The ultimate goal is to implement a WebGIS platform to share all the data collected with local authorities and the Civil Protectio

A novel rule-based approach in mapping landslide susceptibility

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Despite recent advances in developing landslide susceptibility mapping (LSM) techniques, resultant maps are often not transparent, and susceptibility rules are barely made explicit. This weakens the proper understanding of conditioning criteria involved in shaping landslide events at the local scale. Further, a high level of subjectivity in re-classifying susceptibility scores into various classes often downgrades the quality of those maps. Here, we apply a novel rule-based system as an alternative approach for LSM. Therein, the initially assembled rules relate landslide-conditioning factors within individual rule-sets. This is implemented without the complication of applying logical or relational operators. To achieve this, first, Shannon entropy was employed to assess the priority order of landslide-conditioning factors and the uncertainty of each rule within the corresponding rule-sets. Next, the rule-level uncertainties were mapped and used to asses the reliability of the susceptibility map at the local scale (i.e., at pixel-level). A set of If-Then rules were applied to convert susceptibility values to susceptibility classes, where less level of subjectivity is guaranteed. In a case study of Northwest Tasmania in Australia, the performance of the proposed method was assessed by receiver operating characteristics’ area under the curve (AUC). Our method demonstrated promising performance with AUC of 0.934. This was a result of a transparent rule-based approach, where priorities and state/value of landslide-conditioning factors for each pixel were identified. In addition, the uncertainty of susceptibility rules can be readily accessed, interpreted, and replicated. The achieved results demonstrate that the proposed rule-based method is beneficial to derive insights into LSM processes

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

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

Analytic hierarchy process applied to landslide susceptibility mapping of the North Branch of Argentino Lake, Argentina

In the present study, we achieved the susceptibility mapping to slope instability processes by the implementation of Analytic Hierarchy Process and Weighted Linear Combination methods, in the North Branch of Argentino Lake, Southern Patagonian Icefield. The strong retraction of the glaciers in the area has triggered paraglacial readjustments, producing instability processes that favor the generation of mass removal processes. The results obtained from optical satellite images show that the highest degrees of susceptibility (4 and 5) are located on the western slopes of the Upsala Channel, Bertacchi and Cono Tributary Glaciers, and the Moyano and Norte Valleys, respectively. These slopes coincide with the geographic location of previous events surveyed by the inventory of unstable areas of the zone. Low degrees of susceptibility are found on the downhill valleys, outcrops rock and glaciers. The Consistency Ratio was 0.069, indicating that being less than 0.1 the study is reliable. The study sheds light on the knowledge of slopes and valleys that are more susceptible to processes of instability in mountainous areas, which would make it possible to prevent possible hazards associated with these events.Fil: Moragues, Silvana Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Lenzano, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Lanfri, Mario. Comision Nacional de Actividades Espaciales. Gerencia de Coordinacion.; ArgentinaFil: Moreiras, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Lenzano, Luis Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

FLOOD SUSCEPTIBILITY MODELLING USING GEOSPATIAL-BASED MULTI-CRITERIA DECISION MAKING IN LARGE SCALE AREAS

Flood is one of the most hazardous natural disasters that cause damages and poses a major threat to human lives and infrastructures worldwide, and its prevention is almost unfeasible. Thus, the detection of flood susceptible areas can be a key to lessen the amount of destruction and mortality. This study aims to implement a framework to identify flood potential zones in an ungauged large-scale area with frequent flood events in recent years. We used two Multi-Criteria Decision Making (MCDM) approaches combined with geospatial analysis, and remote sensing observations for this susceptibility analysis. Nine geomorphological and environmental factors that have an impact on flood behaviour were selected and used for susceptibility modelling. At first, the criteria’s weights were estimated using two MCDM approaches and based on experts’ knowledge. The resultant weights revealed that Flow Accumulation, Topographic wetness index, and Distance to River were the most influential flood susceptibility criteria. After calculating these weights, the criteria’s layers were aggregated through geospatial analysis, which resulted in generating flood susceptibility map. The area under the curve (AUC) and statistical measures such as the Kappa index were used to evaluate the proposed method's efficiency. The validation results illustrate that hybrid FAHP, with AUC= 96.68 and Kappa = 81.36 performed more efficiently than standard AHP, with AUC= 94.53 and Kappa=76.35. Overlaying these maps with the historical flood inventory dataset revealed that 86.43% of flooded areas were categorized as “high” and “very high”. Therefore, the flood susceptibility maps generated through the proposed approach can help the decision-makers and managers allocate the mitigation equipment and facility in data-scarce and ungauged large-scale areas