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We analyze landslides on Ceres using several quantitative approaches to constrain the composition and structure of the top few kilometers of Ceres' crust. We focus on a subset of archetypal landslides classified morphologically as thick, steep‐snouted "type 1" (T1) flows and thin spatulate "type 2" (T2) flows (Schmidt et al., 2017, https://doi.org/10.1038/ngeo2936) to explore the landslides' mechanical properties. Our results confirm earlier observations showing that T1 landslides are typically found poleward of 70° latitude and T2 mostly equatorward of 70° latitude. Measurements of landslide drop height and runout length imply effective friction coefficients lower than common friction coefficients in any of Ceres' identified or suggested non‐ice surface materials, including saturated clays. Our measurements of the volume and area of landslide scars suggest that T1 landslides can fail to greater depths than T2 for a given scar area, consistent with depth‐limited failure in T2 landslides. These results are consistent with a layer of lower shear strength material overlying a stronger layer in Ceres' outer shell at low to middle latitudes and a single layer without an overlying weak layer at polar latitudes. Combining these observations with known constraints on Ceres' near‐surface composition, we propose that Ceres' crust at low to middle latitudes consists of a topmost layer with an ice content in excess of the spectral and elemental detection depths, thins out at high latitudes, and overlies a stronger and more ice‐rich layer. Plan Language Summary: We use landslides on Ceres to explore the possible ice content and distribution in the upper few kilometers of Ceres. The landslides used here are a subset of the best examples of the main types of landslides identified in earlier work. We confirm that type 1 landslides are only common poleward of 70° latitude and type 2 landslides are commonly equatorward of 70° latitude. Friction coefficients estimated from the landslide drop height and runout length span a range suggestive of ice. Volume and area measurements of the landslide failure scar are consistent with a weak layer overlying a stronger layer at latitudes where type 2 landslides are common and a single layer in the case of type 1 landslides, located primarily in polar latitudes. We propose that the weak layer suggested at middle and low latitudes thins out at the poles and that the stronger layer has higher ice content. Key Points: Landslide types 1 and 2 mobilities are consistent with cold ice and warm ice respectively, with significant overlapType 2 landslides are consistent with a layer of weaker shear strength overlying a stronger one, which we suggest thins out by 70° latitudeWe propose the low shear strength layer contains 3–19 vol% ice with the underlying layer composed of 24–40 vol% ice [ABSTRACT FROM AUTHOR]

Landslide disasters are one of the main risks involved with the operation of long-distance oil and gas pipelines. Because previously established disaster risk models are too subjective, this paper presents a quantitative model for regional risk assessment through an analysis of the patterns of historical landslide disasters along oil and gas pipelines. Using the Guangyuan section of the Lanzhou–Chengdu–Chongqing (LCC) long-distance multiproduct oil pipeline (82 km) in China as a case study, we successively carried out two independent assessments: a susceptibility assessment and a vulnerability assessment. We used an entropy weight method to establish a system for the vulnerability assessment, whereas a Levenberg–Marquardt back propagation (LM-BP) neural network model was used to conduct the susceptibility assessment. The risk assessment was carried out on the basis of two assessments. The first, the system of the vulnerability assessment, considered the pipeline position and the angle between the pipe and the landslide (pipeline laying environmental factors). We also used an interpolation theory to generate the standard sample matrix of the LM-BP neural network. Accordingly, a landslide susceptibility risk zoning map was obtained based on susceptibility and vulnerability assessment. The results show that about 70 % of the slopes were in high-susceptibility areas with a comparatively high landslide possibility and that the southern section of the oil pipeline in the study area was in danger. These results can be used as a guide for preventing and reducing regional hazards, establishing safe routes for both existing and new pipelines, and safely operating pipelines in the Guangyuan area and other segments of the LCC oil pipeline. [ABSTRACT FROM AUTHOR]

We propose a simple method to estimate the surface displacement of earth slides. It is based on the assumptions that earth slides move by sliding along a discrete basal-slip surface and extensional structures, which commonly characterize their depletion zone, completely accommodate the occurred displacement. The proposed method is based on the reconstruction of the cross-sectional geometry of structures crossed by an arbitrary chosen longitudinal profile, aligned with the direction of the movement. Structure geometry reconstruction is completed using high-precision GPS survey and the reconstructed geometry is then used as basis to measure horizontal and vertical components of the displacement accommodated by each single extensional structure. Total horizontal and vertical earth-slide displacements are calculated as the sum of displacements accumulated at each single structure. We test the method at the Summonte earth slide in southern Italy using real-time kinematic GPS field mapping. Results from our estimation were validated considering a single displacement vector derived from the direct and indirect measurement of the position of an isolated tree located below the extensional zone of the slide. [ABSTRACT FROM AUTHOR]

The main aim of this study is the description and the analysis of the monitoring strategies implemented within local landslide early warning systems (Lo-LEWS) operational all around the world. Relevant information on 29 Lo-LEWS have been retrieved from peer-reviewed articles published in scientific journals and proceedings of technical conferences, books, reports, and institutional web pages. The first part of the paper describes the characteristics of these early warning systems considering their different components. The main characteristics of each system are summarized using tables with the aim of providing easily accessible information for technicians, experts, and stakeholders involved in the design and operation of Lo-LEWSs. The second part of the paper describes the monitoring networks adopted within the considered systems. Monitoring strategies are classified in terms of monitored activities and methods detailing the parameters and instruments adopted. The latter are classified as a function of the type of landslide being monitored. The discussion focuses on issues relevant for early warning, including appropriateness of the measurements, redundancy of monitoring methods, data analysis, and performance. Moreover, a description of the most used monitoring parameters and instruments for issuing warnings is presented. [ABSTRACT FROM AUTHOR]

This document describes technical concepts and terms related to landslide risk on slopes and hillsides, from a comprehensive approach. A general methodology is presented for the risk analysis and assessment according to the threat, given by the interrelation susceptibility - probability of landslide occurrence; and the vulnerability of the exposed elements, obtained from a multifactorial analysis that considers physical and social aspects. Susceptibility is obtained considering various conditioning and triggering factors of instability and the probability of event occurrence is estimated from deterministic methods. The vulnerability analysis is done considering the spatial and temporal components of the potential events, as well as the impact that these could have on the exposed elements, in terms of social and material losses. This methodology is applied to the study of an urban slope in the city of Tijuana, Mexico. [ABSTRACT FROM AUTHOR]

Abstract Landslides are a type of mass wasting and denote any downslope movement of soil and rock under the influence of gravity; as such they can represent a dangerous natural hazard process, especially in case that they affect inhabited areas or transport infrastructure. Because the occurrence of landslides is typically favoured by terrain and lithological conditions, the process is frequently concentrated in relatively small, isolated regions exhibiting suitable initial conditions of terrain instability. Extensive regional assessments of landslide activity have been used in the past to uncover common triggers and process patterns, mostly in the aftermath of large, regional disasters. By contrast, however, regional reconstructions of past landslide activity have not been realized with dendrogeomorphic techniques, and with the aim to date past landslide histories over extended time periods and with annual dating precision. This study therefore aims at disentangling landslide dynamics at the regional scale (covering ca. 600 km2) by using growth-ring records of trees that grow on active landslides. The studied area of the Hostýnsko-vsetínská hornatina Mts. (Central Europe) is well known for its high landslide activity, but has so far been lacking a detailed chronology of past events. To this end, we dated past activity on 26 landslide bodies using tree-ring series from 1322 disturbed trees to reconstruct 327 landslide reactivations during the last century. The reconstructed landslide database allowed correlations between landslide types and their frequencies or occurrence, as well as inferences between selected morphometric parameters with landslide frequency and magnitude. We also observe periods of increased landslide activity (1940s, 1960s, 1980s, and 1990s) and events of regional importance (e.g., 1961, 1985, and 1997), as well as a significant decrease in landsliding during the last two decades. Highlights • Regional reconstruction of landslides activity for Outer Western Carpathians • Tree-ring based analysis of 26 landslides • Chronologies of various landslide types • Comparison of activity with the morphometry of landslides [ABSTRACT FROM AUTHOR]

Most regional landslide warning systems utilize empirically derived rainfall thresholds that are difficult to improve without recalibration to additional landslide events. To address this limitation, we explored the use of synthetic rainfall to generate thousands of possible storm patterns and coupled them with a physics‐based hydrology and slope stability model for various antecedent soil saturation scenarios to analyze pore water pressure and factor of safety metrics. We used these metrics to generate two‐tiered alert thresholds that can be employed to assess shallow landslide potential for any given combination of storm and antecedent wetness. When applied to the San Francisco Bay region (CA, USA), the results are consistent with events that caused widespread landsliding. Our deterministic modeling approach, which accounts for plausible ranges in soil hydraulic and mechanical properties, can inform the development of the next generation of warning systems for rainfall‐induced landsliding. Plain Language Summary: Providing accurate warning in advance of rainfall‐induced landsliding can help reduce loss of life and property but requires knowledge of hillslope wetness and future rainfall conditions to forecast when widespread landsliding is likely. However, typical landslide warning systems consider only the rainfall characteristics (e.g., rainfall amount, duration, and/or intensity) that were measured during past landslide events. These are used to define a set of rainfall conditions, or a threshold, for which landsliding should be expected within a given area. When a rainfall threshold does not perform well for subsequent landsliding events, it can be difficult to diagnose the problem because hillslope wetness is not considered. We present an approach to develop landslide thresholds that accounts for both rainfall and hillslope wetness. The results are consistent with historical and recent widespread landsliding events in our study region and, more importantly, can be related to measurable properties of hillslopes. This more direct approach could revolutionize the development of the next generation of landslide warning systems. Key Points: Thresholds for rainfall‐induced landsliding of soil‐mantled hillslopes identified with physics‐based hydrologic and slope stability modelingLibrary of modeled infiltration events based on variations in rainfall and antecedent soil saturation facilitates timely hazard assessmentDeterministic modeling approaches that account for parameter variability can inform the next generation of landslide warning systems [ABSTRACT FROM AUTHOR]

In this work residents' social vulnerability and buildings' physical vulnerability of the Loures municipality (Portugal) were combined to locate the areas where the vulnerability is the highest, and to analyse the landslide risk. The social vulnerability of Loures was assessed using the Geographic Basis for Information Reference (BGRI) terrain units by combining sensitivity and lack of resilience based on the population and housing Census 2011 data. The physical vulnerability was assessed in a previous study based on an inquiry of a pool of European landslide experts and a sub-pool of landslide experts who know the study area. A matrix approach was used to cross the classes of the social and physical vulnerabilities. Finally, the landslide risk was analysed for each terrain unit considering the combined vulnerability, the buildings' economic value and the landslide susceptibility for a specific landslide magnitude (3-metre-deep rotational slide). Results show that 0.9% of the population reside in the area of the municipality where 75% of the future landslide should occur, and 0.8% of the buildings of the municipality--which represent a value of EUR 146,170,000--are also located in this dangerous area. This approach is reproducible: the risk analysis can be applied for another magnitude scenario in Loures, and the combined vulnerability can be assessed in any Portuguese municipality thanks to the availability of the data. [ABSTRACT FROM AUTHOR]

Many landslides were triggered by heavy rainfall from 29 June to 1 July 2017 in Ningxiang County, Hunan Province, China. A field investigation into one of the landslides, known as the Wangjiawan landslide, was undertaken on July 3, 2017, to understand the landslide mechanisms and the factors that triggered the event. The landslide is a translational and rotational slide that degraded downslope to an earth flow. It occurred on a steeply dipping mud-rich slate intercalation. Field investigation shows that the landslide had a movement rate of more than 25 m/s and had been triggered by up to 338 mm of continuous rainfall over 2 days. The landslide was fast-moving because it occurred on a steep slope and showed a rapid reduction in shear strength. The landslide resulted in nine fatalities and 19 injuries, most during initial rescue efforts. To mitigate a possible secondary landslide disaster, later emergency measures including evacuation of the survivors, setting up warning signs, and covering landslide cracks with plastic sheeting were adopted. [ABSTRACT FROM AUTHOR]

Recent investigations have sought to understand the spatial-temporal distribution of landslides in Teziutlán, Puebla, a municipality historically affected by landslides. The latest initiative, under the umbrella of the ICL-IPL Project “Landslide disaster risk communication in mountain areas,” was the publication of a book of Atlas type comprising a collection of 142 maps and their corresponding explanatory texts that included a context analysis of landslide disaster risk drivers at various scales, from regional to local. This paper aims to recognise and address the necessity to further enhance the guiding principle of the Sendai Framework for Disaster Risk Reduction to focus on the understanding of disaster risk drivers at local level, for the determination of measures to reduce disaster risk. We present an initial contribution to promote landslide disaster risk awareness in the urban area of Teziutlán by providing to the community direct access to maps of landslide disaster risk at local scale; this is a first step towards the establishment of a robust strategy to communicate landslide risk in the long term. Effective implementation calls for decreasing vulnerability and exposure. Beyond contexts of vulnerability reflected by social, economic, cultural, political, and institutional conditions, it may be difficult to picture the spatial interactions of exposure of communities, assets, and the environment because the means of analysing spatial relationships between society and nature are not commonly available in mountain areas. Therefore, for people to better understand risk, maps of landslide susceptibility and risk exposure present a good way for the inhabitants to familiarise themselves with the spatial context of the dynamics in which they are immersed. [ABSTRACT FROM AUTHOR]

Research on landslide in Sri Mulyo Village, Dampit Subdistrict, Malang District, Indonesia has been implemented. This research is conducted to know the condition of the subsurface area for information in landslide vulnerability analysis. In addition, this research was undertaken to mitigate landslide in minimizing casualties and material losses. The study was done using resistivity method, configuration of dipole-dipole supported by drilling core lab test result. There are five resistivity measuring lines with trajectory lengths ranging from 100 m, 200 meters, and 300 meters. The results of the resistivity indicate that the subsurface lithology of Sri Mulyo Village is composed of clays (9.3-85.8 Ω.m), tuff (178-779 Ω.m) and breccia (≥ 1629 Ω.m). The sliding plane at the research area is the boundary between clays and tuffs. The result of correlation between geoelectric and drilling core data showed that the research area was dominated by a 10m depth of clay. High rainfall, clay thickness and vegetation (coffee) exhibit high levels of vulnerability to occur landslides. Possible landslide direction is from West-West to Southeast with creep avalanche type. [ABSTRACT FROM AUTHOR]

A massive landslide was triggered on 19 May 2017 at Vishnuprayag near Joshimath, Uttarakhand, India. The landslide blocked the Rishikesh-Badrinath highway and halted traffic for about 24 h till the debris was removed and the road reopened. The Hathi Pahar hill in Vishnuprayag has been a landslide-prone zone because of the presence of loose boulders and large rock blocks on very steep slopes. The site was visited immediately after the landslide and a rapid field assessment of slope stability was carried out. The stability analysis was performed with limited geological and geotechnical data collected from field and laboratory. Based on the two-dimensional finite element analysis, it was inferred that the slope is marginally stable under static load, but fails under seismic loading. The slope could fail in future due to triggering factors such as heavy rainfall, earthquake and anthropogenic activities. This communication presents field observations and the subsequent stability analysis along with possible suggestive control measures. [ABSTRACT FROM AUTHOR]

Stability analysis is of great significance to landslide hazard prevention, especially the dynamic stability. However, many existing stability analysis methods are difficult to analyse the continuous landslide stability and its changing regularities in a uniform criterion due to the unique landslide geological conditions. Based on the relationship between displacement monitoring data, deformation states and landslide stability, a state fusion entropy method is herein proposed to derive landslide instability through a comprehensive multi-attribute entropy analysis of deformation states, which are defined by a proposed joint clustering method combining K-means and a cloud model. Taking Xintan landslide as the detailed case study, cumulative state fusion entropy presents an obvious increasing trend after the landslide entered accelerative deformation stage and historical maxima match highly with landslide macroscopic deformation behaviours in key time nodes. Reasonable results are also obtained in its application to several other landslides in the Three Gorges Reservoir in China. Combined with field survey, state fusion entropy may serve for assessing landslide stability and judging landslide evolutionary stages. [ABSTRACT FROM AUTHOR]

In the face of climate change, the assessment of land transport infrastructure exposure towards adverse climate events is of major importance for Europe's economic prosperity and social wellbeing. In this study, a climate index estimating rainfall patterns which trigger landslides in central Europe is analysed until the end of this century and compared to present-day conditions. The analysis of the potential future development of landslide risk is based on an ensemble of dynamically downscaled climate projections which are driven by the SRES A1B socio-economic scenario. Resulting regional-scale climate change projections across central Europe are concatenated with Europe's road and railway network. Results indicate overall increases of landslide occurrence. While flat terrain at low altitudes exhibits an increase of about 1 more potentially landslide-inducing rainfall period per year until the end of this century, higher elevated regions are more affected and show increases of up to 14 additional periods. This general spatial distribution emerges in the near future (2021-2050) but becomes more pronounced in the remote future (2071-2100). Since largest increases are to be found in Alsace, potential impacts of an increasing amount of landslides are discussed using the example of a case study covering the Black Forest mountain range in Baden-Württemberg by further enriching the climate information with additional geodata. The findings derived are suitable to support political decision makers and European authorities in transport, freight and logistics by offering detailed information on which parts of Europe's ground transport network are at particularly high risk concerning landslide activity. [ABSTRACT FROM AUTHOR]

This study evaluated the generalizability of five models to select a suitable approach for landslide susceptibility modeling in data-scarce environments. In total, 418 landslide inventories and 18 landslide conditioning factors were analyzed. Multicollinearity and factor optimization were investigated before data modeling, and two experiments were then conducted. In each experiment, five susceptibility maps were produced based on support vector machine (SVM), random forest (RF), weight-of-evidence (WoE), ridge regression (Rid_R), and robust regression (RR) models. The highest accuracy ( AUC = 0.85) was achieved with the SVM model when either the full or limited landslide inventories were used. Furthermore, the RF and WoE models were severely affected when less landslide samples were used for training. The other models were affected slightly when the training samples were limited. [ABSTRACT FROM AUTHOR]

Landslide is a natural hazard that results in many economic damages and human losses every year. Numerous researchers have studied landslide susceptibility mapping (LSM), each attempting to improve the accuracy of the final outputs. However, few studies have been published on the training data selection effects on the LSM. Thus, this study assesses the training landslides random selection effects on support vector machine (SVM) accuracy, logistic regression (LR) and artificial neural networks (ANN) models for LSM in a catchment at the Dodangeh watershed, Mazandaran province, Iran. A 160 landslide locations inventory was collected by Geological Survey of Iran for this investigation. Different methods were implemented to define the landslide locations, such as inventory reports, satellite images and field survey. Moreover, 14 landslide conditioning factors were considered in the analysis of landslide susceptibility. These factors include curvature, plan curvature, profile curvature, altitude, slope angle, slope aspect, distance to faults, distance to stream, topographic wetness index, stream power index, terrain roughness index, sediment transport index, lithology and land use. The results show that the random landslide training data selection affected the parameter estimations of the SVM, LR and ANN algorithms. The results also show that the training samples selection had an effect on the accuracy of the susceptibility model because landslide conditioning factors vary according to the geographic locations in the study area. The LR model was found to be less sensitive than the SVM and ANN models to the training samples selection. Validation results showed that SVM and LR models outperformed the ANN model for all scenarios. The average overall accuracy of LR, SVM and ANN models are 81.42%, 79.82% and 70.2%, respectively. [ABSTRACT FROM AUTHOR]

Seismically-induced landslides can be detrimental to urban communities, often resulting in significant damage and repair costs, blockage of lifeline connection routes and utilities, environmental impacts, and potential for loss of life. Consistent, reliable hazard maps can assist agencies to efficiently allocate limited resources to prepare for these events. This paper presents methodology for evaluating and mapping seismically-induced landslide hazards across a large area utilizing performance-based design strategies. This approach scales site-specific seismic hazard curve analysis techniques to a regional scale evaluation by combining generally available data, including: previous landslide inventories, lidar and photogrammetric topographic data, geologic mapping, NEHRP site classifications based on shear wave velocity (VS30) measurements, and seismic hazard curves for the analysis. These maps can be combined with maps generated for other hazards (e.g., liquefaction) for a fully probabilistic, multi-hazard evaluation and risk assessment. To demonstrate the methodology, a series of landslide hazard maps showing the probabilities of exceeding different thresholds of movement (e.g., 0.1, 0.3, and 1.0 m) were generated for western Oregon. The study area contains weak, wet soils that experience land sliding regularly even without significant seismic activity. The maps show reasonable agreement with landslide inventory and susceptibility maps. [ABSTRACT FROM AUTHOR]

The World Landslide Forum is a triennial mainstream conference that gathers together the scientific and technological community, policymakers, industry actors, public officials, and other stakeholders, who deal with the understanding and management of landslide disaster risk. The establishment of the ISDR-ICL Sendai Partnerships 2015-2025 for Global Promotion of Understanding and Reducing Landslide Disaster Risk in Sendai during the 2015 World Conference on Disaster Risk Reduction (WCDRR) enabled the landslide science and technology community support the implementation of the Sendai Framework for Disaster Risk Reduction 2015-2030 in order to prevent new and reduce existing disaster risk. The 4th World Landslide Forum (WLF4) was held in Ljubljana, Slovenia, from 29 May to 2 June 2017 and discussed the progress of landslide research and risk reduction for advancing the culture of living with natural hazards. A high-level panel composed of United Nations officials, international stakeholders, and national organizations sought to identify the best mechanisms to be developed by the community of the International Consortium on Landslides (ICL). The objective was to advance the implementation of the ISDR-ICL Sendai Partnerships, to achieve a better commitment among partners, and to provide substantive services to developing countries. During the WLF4, the 2017 Ljubljana Declaration on Landslide Risk Reduction was adopted and the concept framework of the Kyoto 2020 Commitment was endorsed. [ABSTRACT FROM AUTHOR]

The primary objective of the current study is to better understand landslide hazards in reservoir areas and the mechanism of reservoir landslides using different methods. To achieve this main objective the Xiangjiaba Reservoir area, Southwest China is taken as a case study. First, landslide mapping and spatial analysis in the Xiangjiaba Reservoir area were conducted by air photo interpretation (API), followed by field checks. Second, landslide susceptibility mapping was done using the information value method and a logistic regression model. Through remote sensing interpretation coupled with field investigations, 62 landslides, 38 rockfall deposits, and 10 bedrock deformed bodies along the banks of the Xiangjiaba Reservoir area which have effects on the reservoir and resettlements were considered, with a total volume of 32,228 x 104 m³, 19,916 x 104 m³, 1,072 x 104 m³, respectively. Geological characteristics of the reservoir slopes and spatial prediction indicate that after filling the reservoir to a normal level of 380 m, 23 landslides among the total identified landslides are stable, six landslides have been mitigated, and all of the rest are unstable. Thirty-two rockfall deposits are still in a stable state, and the rest are unstable. By overlaying the existing landslide and the susceptibility map, it is found that 0.36% of the existing landslides are in areas of very low susceptibility, 1.77% are in areas of low susceptibility, 4.14% are in areas of moderate susceptibility, 6.04% are in areas of high susceptibility, and 13.37% are in areas of very high susceptibility. [ABSTRACT FROM AUTHOR]

This study attempts to compare popular statistical methods (linear, logarithmic, quadratic, power and exponential functions) with machine learning methods (multi-layer perceptron (MLP), radial base function (RBF), adaptive neural-based fuzzy inference system (ANFIS) and support vector machine (SVM)) for simulating the volume of landslides based on their surface area (VL ~ AL) in the Kurdistan province, Iran. Performances of the models were validated using some commonly error functions including the Adjusted R 2 , F-test and AIC (Akaike Information Criteria). The results showed that the power model demonstrates the best performance compared to other statistical methods whereas the ANFIS model outperforms other machine learning approaches. Furthermore, the comparative results showed that machine learning methods indicate better performances than simple statistical methods for simulating the volume of landslides in the study area. In practice, the outputs of this research can help managers and investigators decrease the cost of field surveys and measurements of volumes of landslides in landslide hazard management projects. [ABSTRACT FROM AUTHOR]

Complete landslide inventories are rarely available. The objectives of this study were to (i) elaborate the influence of incomplete landslide inventories on statistical landslide susceptibility models and to (ii) propose suitable modelling strategies that can reduce the effects of inventory-based incompleteness. In this context, we examined whether the application of a novel statistical approach, namely mixed-effects models, enables predictions that are less influenced by such inventory-based errors. The study was conducted for (i) an area located in eastern Austria and (ii) a synthetically generated data set. The applied methodology consisted of a simulation of two different inventory-based biases and an in-depth evaluation of subsequent modelling results. Inventory-based errors were simulated by gradually removing landslide data within forests and selected municipalities. The resulting differently biased inventories were introduced into logistic regression models while we considered the effects of including or excluding predictors that are directly related to the respective inventory-based bias. Mixed-effects logistic regression was used to account for variation that was due to an inventory-based incompleteness. The results show that most erroneous predictions, but highest predictive performances, were obtained from models generated with highly incomplete inventories and predictors that were able to directly describe the respective incompleteness. An exclusion of such bias-describing predictors led to systematically confounded relationships. The application of mixed-effects models proved valuable to produce predictions that were least affected by inventory-based errors. This paper highlights that the degree of inventory-based incompleteness is only one of several aspects that determine how an inventory-based bias may propagate into the final results. We propose a four-step procedure to deal with incomplete inventories in the context of statistical landslide susceptibility modelling. [ABSTRACT FROM AUTHOR]

The ANNEX to the 2017 Ljubljana Declaration on Landslide Risk Reduction described in the 'Preface' section of this issue is the list of participants (by organizations) in the Fourth World Landslide Forum. In this article, emphasis is put on this list of organizations as they are expected to be the key components for the Fifth World Landslide Forum 2020 in Kyoto, Japan. The participants in the Fourth World Landslide Forum 2017 adopted the 2017 Ljubljana Declaration on Landslide Risk Reduction. They further endorsed the concept of the Kyoto 2020 Commitment for Global Promotion of Understanding and Reducing Landslide Disaster Risk. The commitment aims to establish a long-term, wider, and stronger network after WLF5 2020 among three membership categories, namely, the International Consortium on Landslides (ICL) full members/supporters/associates, ICL-supporting organizations (UN and international global organizations) and ICL-supporting governments, and ISDR-ICL Sendai Partnerships 2015-2025. This article introduces three categories of ICL memberships and calls for participation. [ABSTRACT FROM AUTHOR]

Scientific literature is becoming daily more and more abundant. Scientific and professional journals as primary information sources are competing to each other to attract readership. Their position (ranking, visibility, attractiveness, prestige) in scientific community can be measured by using different journal bibliometric and scientometric parameters, journal impact factor being only one of them. Springer Nature publishes the journal Landslides: Journal of the International Consortium on Landslides since 2004. Being examined in the past by different authors from bibliometric and editorial point of view, this review on the journal's achievements confirmed the high ranking of this journal in the fields of geological and geotechnical engineering and engineering geology. Strong and weak points are discussed from the bibliometric point of view, stressing the need for higher internationality of co-authorship of published articles in order to be true international journal. Continuous publishing and the move to a monthly journal in 2018 will eventually increase journal's h-index and cited half-life of citations, but further editorial efforts should be directed to attract excellent review papers and focused technical notes to increase cites per paper. Until now, the journal Landslides is the foremost journal in the field of landslide disaster risk reduction, and the top young international journal in the field of geological engineering and engineering geology. [ABSTRACT FROM AUTHOR]

The Fourth World Landslide Forum (WLF4) was held in Cankarjev dom-Cultural and Congress Centre in Ljubljana, Slovenia, from 30 May to 2 June 2017, with over 600 participants from 49 countries, 5 international organizations, and 4 United Nations organizations-scientists, engineers, researchers, students, experts, politicians, and other decision makers working in the area of landslide risk reduction. Well, over 100 of them were (post)graduate students. The WLF4 as a triennial event was a contribution of the International Consortium on Landslides (ICL) to the implementation of the Sendai Framework for Disaster Risk Reduction 2015-2030. This article reports on the main WLF4 events and outcomes of the forum. Altogether, close to 400 peer-reviewed full papers, including keynote, invited, and other submitted papers, were published by Springer Nature in five volumes with a total of over 3600 pages. During the WLF4, 20 new World Centres of Excellence on Landslide Risk Reduction for 2017-2020, IPL Awards for Success, Varnes Medals, Best Paper Awards, and other means of recognitions were handed out to the recipients. The WLF4 participants have adopted the '2017 Ljubljana Declaration,' and drafted the 'Kyoto 2020 Commitment,' in order to stress their strong and joint commitment for the ISDR-ICL Sendai Partnerships 2015-2025 on its way towards the Fifth World Landslide Forum to be held in November 2020 in Kyoto, Japan. [ABSTRACT FROM AUTHOR]

Aiming at a landslide appeared during the creep deformation in the south slope of an open-pit mine， the surface morphology of the west boundary of the landslide was determined by using the on-site measurement and the INSAR technique when the east and south boundary shape were already known. Meanwhile， the underground sliding surface was determined by micro-seismic monitoring technique and the west boundary shape was determined according to the surface morphology and the underground sliding surface. Both the geological horizons in the main researching area and the bottom sliding surface of the landslide body were established by the 3D modeling technique. The west boundary shape provides a theoretical basis for the following determination of the landslide shape in the south slope. This collaborative monitoring programme can be a reference for mine slope monitoring under the similar condition. [ABSTRACT FROM AUTHOR]

The landslides caused by the 5.12 Wenchuan earthquake resulted in enormous casualties and property losses. Since the earthquake, more than 3,600 landslides have occurred, and 17 of them were catastrophic, each of which has killed more than 30 people. Meanwhile, passive flexible protection has gradually been introduced to resist landslides due to its significant advantages of economy, safety, and environmental protection. To resist landslides effectively, it is necessary to study the load path and design method of passive flexible protection under the action of landslides. In the design of passive flexible protection against landslides, determination of the landslide load is the primary task. In this paper, the formulas of the probability density function and distribution function of the landslide pressure are developed to obtain the value of the accumulated landslide pressure acting on the passive flexible protection, which can be used as the load input parameter in the design of passive flexible protection to resist landslides. Based on the case of the 'Shiziliang' potential landslide for the 5.12 earthquake, the pressure data of the landslide are collected, the calculation formulas of the volume, and the pressure of the intercepted landslide are established, and the statistical parameters of the landslide pressure-loading sample are obtained. According to the Kolmogorov-Smirnov test method, the loading sample of the landslide pressure obeys an extreme-value type-I distribution, and then the load model of the landslide pressure is determined. Based on the reliability analysis method, the standard value of the landslide pressure with an over-95% assurance rate is obtained. These results can provide references for load confirmation to design the passive flexible protection to resist landslides. [ABSTRACT FROM AUTHOR]

Landslide hazard has always been a focus of research of scientific and industrial organizations in Russia, as well as the former Soviet Union . This research included a broad spectrum of studies of landslide processes based on monitoring data collected at specialized stations nationwide, as well as the data collected and analyzed by various government and academic research institutions. The current study summarizes a vast body of knowledge encompassing an inventory of landslide cases, overview of mechanisms of landslide development and monitoring and slope stability assessments. It presents a new mechanism-based landslide classification and proposes a practical method of increasing slope resistance. Partial findings have been previously presented in numerous publications. We believe these findings have a worldwide significance and can be applied in different regions of our planet. [ABSTRACT FROM AUTHOR]

The following article is related to different ways of slope stability assessment accepted in the Eurocodes and national codes of practice. The landslides studying history is briefly considered. The Eurocode 7 and 8 structure is described and some features of their application are listed. Differences between deterministic and probabilistic methods are shown. Examples of stability design schemes based on limiting equilibrium and also with seismic loads are given. The aspects of the slope reliability estimation using the reliability index are considered. Some disadvantages of reviewed slope stability assessment ways are listed and some recommendations for the new Codes of practice development are given. [ABSTRACT FROM AUTHOR]

Construction and operation of transport infrastructure in the mountainous areas is an extremely important task. The complex structural-tectonic conditions with highly broken relief contribute to the development of modern landslide processes. Unexpected landslide activity carries a significant threat to both the road and transport infrastructure, as well as the life and health of people who use it. There are now known many different methods for protection of transport infrastructure by landslides, but the classic methods are not sufficiently effective to ensure reliable work of roads in mountainous areas and the considerable material costs involved are not justified. The reason for this is often the heterogeneity of a soil in composition and properties. A solution to this problem is to use suspension grouting to stabilize the landslide body. It was found that the injection of cement slurries with high water-cement ratio is only possible in weathered mudstone with cracks width> 10 mm, with injection pressure less than 6 atm. In this case, there is a uniform filling of cracks at a distance of 1, 5-2,0 meters from the injector. When the injection pressure increase occurs the hydraulic fracturing with the output hydraulic cement slurry to the surface. Processing of dense unweathered mudstone by suspension of colloidal silica with a concentration of 29% is possible to obtain a solid array with high strength characteristics that do not change even after 10 cycles of soaking/drying. [ABSTRACT FROM AUTHOR]

In practice, in the performance of engineering and geological surveys anisotropy of soil strength is often considered not fully. One of the main problems in modeling the stability of rock landslide is an objective consideration of the influence of the parameters of cracks and other surface section on the calculation results. On the one hand, the study of fracture is always a certain measurement error, on the other, that the strength against cracking, in many cases, will determine the stability of the rock mass. It appears that the most promising approach is the simulation of fracture using the anisotropy of soil strength calculations of rock landslides. The article considers the influence of the anisotropy of the strength of the slope of the array of soil on the results of quantitative assessment of the overall stability of the slope. Strength criteria are considered grounds for taking account of anisotropy, the limitations of existing approaches to quantify the stability of slopes, describes the principles of probabilistic analysis in the analysis of the anisotropy of the strength properties of the soil. The possibility of obtaining estimates of probability of landslide deformation, which can then be used in geological risk analysis. [ABSTRACT FROM AUTHOR]

Customary methods for landslide detection are labor demanding, time consuming and costly. Moreover, it becomes a real challenge to map event triggered landslides using customary techniques. Various automatic and semi-automatic techniques have been proposed for landslide detection. These techniques require extensive technical knowledge and familiarity of the selected study area for visual interpretation, suitable sampling selection, manual parameterization and the trial and error approach for selection of thresholds which makes the process irreproducible. In this context, the purpose of this study is to introduce and investigate the applicability of an automatic technique of Cosi-Corr (Co-registration of Optically Sensed Images and Correlation) for landslide identification on regional scale using high resolution orthorectified worldwies 2 images. Unlike, conventional pixel based semi-automatic methods which depends on spectral properties of pixels, this method is based on pixels shift. The correlation process was performed by using the Cosi-Corr software. The ground displacement field measured from the correlation indicates high displacement values for landslides triggered by 2010 Haiti earthquake. The method automatically identified more than 73% of co-seismic landslides at the threshold value of 3.75. The adopted procedure proposes a quick and economic way for automatic detection of coseismic landslides on regional scale if suitable pre- and post-event satellite data is available. One limitation of this method is that it does not show any unique behavioral characteristics for different types of landslides so that they could be easily distinguished or classified. [ABSTRACT FROM AUTHOR]

The development of an early warning system for landslides due to rainfall has become an indispensable part for landslide risk mitigation. This paper explains the application of the hydrological FLaIR (Forecasting of Landslides Induced by Rainfall) model, correlating rainfall amount and landslide events. The FLaIR model comprises of two modules: RL (Rainfall-Landslide) which correlates rainfall and landslide occurrence and RF (Rainfall-Forecasting) which allows simulation of future rainfall events. The model can predetermine landslides based on identification of mobility function Y(.) which links actual rainfall and incidence of landslide occurrence. The critical value of mobility function was analyzed using 1st July 2015 event and applying it to 2016 monsoon to validate the results. These rainfall thresholds presented can be improved with intense hourly rainfall and landslide inventory data. This paper describes the details of the model and its performance for the study area. [ABSTRACT FROM AUTHOR]

Landslide susceptibility assessment using GIS has been done for part of Uttarakhand region of Himalaya (India) with the objective of comparing the predictive capability of three different machine learning methods, namely sequential minimal optimization-based support vector machines (SMOSVM), vote feature intervals (VFI), and logistic regression (LR) for spatial prediction of landslide occurrence. Out of these three methods, the SMOSVM and VFI are state-of-the-art methods for binary classification problems but have not been applied for landslide prediction, whereas the LR is known as a popular method for landslide susceptibility assessment. In the study, a total of 430 historical landslide polygons and 11 landslide affecting factors such as slope angle, slope aspect, elevation, curvature, lithology, soil, land cover, distance to roads, distance to rivers, distance to lineaments, and rainfall were selected for landslide analysis. For validation and comparison, statistical index-based methods and the receiver operating characteristic curve have been used. Analysis results show that all these models have good performance for landslide spatial prediction but the SMOSVM model has the highest predictive capability, followed by the VFI model, and the LR model, respectively. Thus, SMOSVM is a better model for landslide prediction and can be used for landslide susceptibility mapping of landslide-prone areas. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to analyze landslide risk public awareness and knowledge in Mexico based on people's common understanding and perception of landsliding associated with previous events. The methodology involved the design and application of a risk perception questionnaire in the municipality of Teziutlán, Puebla, Mexico, an area that has been historically affected by mass movement processes, particularly during a rainfall induced landslide disaster event in October 1999. Sampling framework comprised two boroughs; Downtown Teziutlán (DTT, N = 65), and San Andrés neighborhood (SAN, N = 72). The former has no evidence of landslide risk, whereas the latter has been affected by landsliding. The questionnaire included the following items: (1) experience, (2) landslide risk awareness, (3) exposure, (4) preparedness, (5) responsibility, (6) response, and (7) trust. Results suggested that all the inhabitants of the sample are aware of risk of landsliding and consider the dwellings situated in the city center as the safest. The latter is consistent with a landslide susceptibility map on which hillslope material properties are reflected and lithological units of highest resistance are located beneath the city center. The need of undertaking different initiatives to achieve disaster risk reduction at community level was clearly expressed by the respondents in terms of ranking all the actions listed in the questionnaire as of high and moderate priority to improve the security of the residents. Highest accountability for actions in case of a landslide disaster was attached to the Mexican Army, as it is in charge of disaster response nationwide. Responses provided by the municipal government, health institutions and the Red Cross in DTT and by the state and municipal government along with civil protection in SAN were perceived as bad or just sufficient. High level of people's confidence to get information on landslide disaster preparedness and response from the Red Cross and scientists was also perceived in the two communities. From the outcome of the present investigation, it is possible to conclude and reinforce the argument that a better understanding on how landsliding is perceived is one of the most significant issues for enhancing landslide disaster risk awareness and knowledge and to guarantee the advance of resilient communities at individual and collective scales. [ABSTRACT FROM AUTHOR]

Climate change has increased the frequency and intensity of weather-related natural hazards everywhere. In particular, mountain areas with dense human settlements, such as the Italian Alps, stand to suffer the costliest consequences from landslides. Options for risk management policies are currently being debated among residents and decision makers. Preference analysis of residents for risk reduction programs is hence needed to inform the policy debate. We use discrete choice experiments to investigate the social demand for landslide protection projects. Given the importance of information in public good valuation via surveys, we explore the effect of specific visual information on the stability of preference estimates. In our survey, we elicit preferences before and after providing respondents with scientific-based information, based on visual simulations of possible events. This enables us to measure information effects. Choice data are used to estimate a Mixed Logit (MXL) model in WTP space to obtain robust estimates of marginal willingness-to-pay (mWTP) estimates and control for the effect of information. Mapping posterior individual specific mWTP estimates provide additional policy implications. Overall, we found the mWTP estimates to be dependent on information. [ABSTRACT FROM AUTHOR]

The Daguangbao mega-landslide (China), induced by the 2008 Wenchuan earthquake (M w = 7.9), with an area of approximately 8 km 2 , is one of the largest landslides in the world. Experts predicted that the potential risk and instability of the landslide might remain for many decades, or even longer. Monitoring the activity of such a large landslide is hence critical. Terrain Observation by Progressive Scans (TOPS) mode from the Sentinel-1 satellite provides us with up-to-date high-quality Synthetic Aperture Radar (SAR) images over a wide ground coverage (250 × 250 km), enabling full exploitation of various InSAR applications. However, the TOPS mode introduces azimuth-dependent Doppler variations to radar signals, which requires an additional processing step especially for SAR interferometry. Sentinel-1 TOPS data have been widely applied to earthquakes, but the performance of TOPS data-based time series analysis requires further exploitation. In this study, Sentinel-1 TOPS data were employed to investigate landslide post-seismic activities for the first time. To deal with the azimuth-dependent Doppler variations, a processing chain of TOPS time series interferometry approach was developed. Since the Daguangbao landslide is as a result of the collapse of a whole mountain caused by the 2008 Mw 7.9 Wenchuan earthquake, the existing Digital Elevation Models (DEMs, e.g. SRTM and ASTER) exhibit height differences of up to approximately 500 m. Tandem-X images acquired after the earthquake were used to generate a high resolution post-seismic DEM. The high gradient topographic errors of the SRTM DEM (i.e. the differences between the pre-seismic SRTM and the actual post-seismic elevation), together with low coherence in mountainous areas make it difficult to derive a precise DEM using the traditional InSAR processing procedure. A re-flattening iterative method was hence developed to generate a precise TanDEM-X DEM in this study. The volume of the coseismic Daguangbao landslide was estimated to be of 1.189 ± 0.110 × 10 9 m 3 by comparing the postseismic Tandem-X DEM with the preseismic SRTM DEM, which is consistent with the engineering geological survey result. The time-series results from Sentinel-1 show that some sectors of the Daguangbao landslide are still active (and displaying four sliding zones) and exhibiting a maximum displacement rate of 8 cm/year, even eight years after the Wenchuan earthquake. The good performance of TOPS in this time series analysis indicates that up-to-date high-quality TOPS data with spatiotemporal baselines offer significant potential in terms of future InSAR applications. [ABSTRACT FROM AUTHOR]

Landslide risk assessments are usually permeated by a certain degree of subjectivity. In order to reduce it, we have developed an original methodology which enables risk assessments to be carried out in fully quantitative terms, integrating both physical and economic science techniques. This risk assessment combines geomorphological studies, probabilistic modelling and cost-benefit analyses (CBA). We applied the methodology to an area of north-west Italy that was affected in 2011 by a dramatic rainfall-induced landslide event, and where a risk management program is necessary for avoiding future losses. We analyzed the cost-effectiveness of several landslide mitigation measures applying the proposed procedure. The results demonstrate that measures previously considered as suitable for mitigating shallow landslides were inappropriate from the economic viewpoint. The applied techniques also served to optimize economically the most appropriate mitigation measure. Moreover, our methodology allowed to calculate the maximum affordable investment on a cost-effective mitigation measure; this result will be a reference for designing innovative solutions to mitigate landslides in the study area. [ABSTRACT FROM AUTHOR]

This paper deals with a quantitative risk analysis, performed using the rockfall risk management (RO.MA.) method, for a road affected by rockfalls. This approach allows evaluating the rockfall risk, also considering existing protection devices. Rockfall hazard and risk were assessed for an important and very busy road stretch linking Positano to Amalfi in the Campania region of southern Italy. An estimate of the rockfall return periods for assigned volume classes was obtained using the magnitude-frequency curves (MFCs) computed through the analysis of a rockfall inventory covering a time span from 1996 to 2008. For rockfall volumes of 0.1, 1.0, and 10 m, using a 2D trajectory simulating code, the involved kinetic energies and run-out distances of boulders that may hit the road were calculated. The risk, expressed as the annual probability of a fatal accident for the three rockfall hazard scenarios has been evaluated both without and with protection devices, respectively. The total final risk is given by the sum of partial risks related to the three scenarios. The analysis showed that regardless of whether there are any rockfall protection devices, the total risk remains almost constant. This is due to the wide spread of slopes protected with inadequate restraining metallic nets characterized by decreasing catching capacities, as possible rockfall magnitude increases. The individual risk is not acceptable, and some actions are requested in order to lower it. [ABSTRACT FROM AUTHOR]

Scientific literature is replete with papers describing advances in applying new technologies to the study of landslides and advances in our understanding of factors affecting landslide occurrence, distribution, and movement. Far fewer papers look at how this knowledge is implemented to achieve landslide risk reduction. State and local governments exercise the greatest control on how landslide risk reduction is accomplished. Data generated from a questionnaire to state geological surveys, review of their agency Web sites, and two case studies demonstrate that progress has been made during the last 20 years in implementing actionable policy changes and programs to achieve a reduction is landslide risk in the United States. Progress is evident from the pivotal role played by state and local government in the areas of: (1) developing guidelines and training, (2) increasing public awareness and education, (3) implementing loss reduction measures, and (4) conducting emergency preparedness, response, and recovery. The number of states requiring registration for practicing geologists has nearly doubled during the last 20 years. This increase was accompanied by a shift from individual state tests as part of determining competency to a uniform national test. During this period, state geological surveys established Web sites as a primary means for promoting public awareness and education about landslide hazards. Measures reducing the impact of landslides have included providing information specific to residents and landowners, as well as supporting land-use planning efforts by local governments. Many state geological surveys are involved with emergency management of landslide hazards. [ABSTRACT FROM AUTHOR]

The main goal of this study is to produce landslide susceptibility maps by frequency ratio (FR) and index of entropy (IoE) models based on geographic information system (GIS) for the Daguan county of Yunnan province, China. At first, landslide locations were identified by earlier reports and aerial photographs as well as by carrying out field surveys, and a total of 194 landside locations were constructed from various sources. Then the landslide inventory map was randomly split into a training dataset 70 % (136 landslide locations) for training the FR and IoE models and the remaining 30 % (58 landslides locations) were used for validation purposes. Fifteen landslide conditioning factors were constructed in GIS. The susceptibility maps produced using FR and IoE models were divided into five different susceptibility classes such as very low, low, moderate, high, and very high. Finally, the validation of landslide susceptibility maps was carried out based on training dataset and the validation data using the area under the curve (AUC) method. The success rate curve showed that the area under the curve for FR and IoE models were 0.8191 and 0.8109 accuracy, respectively. Similarly, the validation result showed that the prediction accuracy of the two models was 81.75 % for FR model and 81.44 % for IoE model, respectively. The maps produced by both models exhibits better satisfactory properties. The landslide susceptibility maps may be useful for planning purposes for environmental protection and natural hazard mitigation studies in the near future. [ABSTRACT FROM AUTHOR]

This paper provides a quantitative assessment for the hazard, the vulnerability and the risk associated to slope instability as a tool for urban planners and policy makers. Analysis methodologies and overall numerical procedures are presented in detail. In order to assess a hazard, which is expressed as a temporal probability, FOSM technique was used along with Rosenblueth's point estimate method. Reliability index (β) was used as a standard measure to compare the results assessed with other information presented in published literature for a number of geotechnical projects. Concerning the analysis of vulnerability, a new approach was proposed by combining local methodology for seismic vulnerability designed for buildings in Medellin with generic analysis methodology for vulnerability of people when exposed to landslides. The risk was assessed by a simple mathematical crossing between hazard and vulnerability. A database of 120 residential projects located on natural slopes in the city of Medellin (Colombia) was used for the analysis. The results were presented as FN charts relating the calculated frequency of landslides to the number of potential life or economic losses. [ABSTRACT FROM AUTHOR]

This paper demonstrates an innovative role for experts in supporting participatory policy processes with an application to landslide risk management in the Italian town of Nocera Inferiore. Experts co-produce risk mitigation options based on their specialized knowledge taking account of local knowledge and values by directly coupling stakeholder discourses with option design. Drawing on the theory of plural rationality and based on a literature review, interviews and a public questionnaire, stakeholder discourses are elicited on the landslide risk problem and its solution. Armed with the discourses and in close interaction with stakeholders, experts provide a range of technical mitigation options, each within a given budget constraint. These options are subsequently deliberated in the participatory process with the intent of reaching compromise recommendations for landslide risk mitigation. As we show in an accompanying paper, 'Compromise not consensus. Designing a participatory process for landslide risk mitigation' (this issue), the provision of multiple co-produced policy options enhances stakeholder deliberation by respecting legitimate differences in values and worldviews. [ABSTRACT FROM AUTHOR]

With the escalating costs of landslides, the challenge for local authorities is to develop institutional arrangements for landslide risk management that are viewed as efficient, feasible and fair by those affected. For this purpose, the participation of stakeholders in the decision-making process is mandated by the European Union as a way of improving its perceived legitimacy and transparency. This paper reports on an analytical-deliberative process for selecting landslide risk mitigation measures in the town of Nocera Inferiore in southern Italy. The process was structured as a series of meetings with a group of selected residents and several parallel activities open to the public. The preparatory work included a literature/media review, semi-structured interviews carried out with key local stakeholders and a survey eliciting residents' views on landslide risk management. The main point of departure in the design of this process was the explicit elicitation and structuring of multiple worldviews (or perspectives) among the participants with respect to the nature of the problem and its solution. Rather than eliciting preferences using decision analytical methods (e.g. utility theory or multi-criteria evaluation), this process built on a body of research-based on the theory of plural rationality-that has teased out the limited number of contending and socially constructed definitions of problem-and-solution that are able to achieve viability. This framing proved effective in structuring participants' views and arriving at a compromise recommendation (not, as is often aimed for, a consensus) on measures for reducing landslide risk. Experts played a unique role in this process by providing a range of policy options that corresponded to the different perspectives held by the participants. [ABSTRACT FROM AUTHOR]

Despite continuing technological advancement in hazard and vulnerability assessment, risk modelling and hazard mitigation techniques, losses to disasters associated with natural hazards continue and in some cases are increasing across Europe and worldwide. This paper focuses on the need to bridge the gap between technical solutions and the sociopolitical contexts in which these are produced, to better understand and create more effective risk management regimes. We do so with application of the science-policy co-production frame to landslide risk management in Italy. The methodology deployed included a desk study informed by semi-structured interviews carried out with selected key stakeholders at national, regional and municipal level. We propose a normative and analytical framework for transferring co-production into natural hazard research by presenting a matrix identifying four contexts within which co-production may unfold. The matrix is based on two axes, which distinguish between innovation and its absence in science and policy domains. We examine several examples of co-production, such as the water-soil integrated approach to risk management or the implementation of hazard/risk assessment. The results highlight that the insulation of science from the institutional context within which knowledge is produced and used is a very problematic issue. This often hinders the implementation of desirable policies and undermines the effectiveness of interventions. Moreover, innovation in science and policy does not automatically result in successful solutions for landslide risk management. Finally, results confirm the utility of co-production but also highlight methodological challenges associated with the introduction of this new conceptual paradigm into the well-structured communities of scientists and policy-makers. [ABSTRACT FROM AUTHOR]

This work provides a multi-temporal and spatial investigation of landslide effects in the San Fratello area (Messina province within the Sicily region, Italy), by means of C-band and X-band Persistent Scatterer Interferometry (PSI) data, integrated with in situ field checks and a crack pattern survey. The Sicily region is extensively affected by hydrogeological hazards since several landslides regularly involved local areas across time. In particular, intense and catastrophic landslide phenomena have recently occurred in the San Fratello area; the last event took place in February 2010, causing large economic damage. Thus, the need for an accurate ground motions and impacts mapping and monitoring turns out to be significantly effective, in order to better identify active unstable areas and to help proper risk-mitigation measures planning. The combined use of historical and recent C-band satellites and current X-band Synthetic Aperture Radar sensors of a new generation permits spatially and temporally detection of landslide-induced motions on a local scale and to properly provide a complete multi-temporal evaluation of their effects on the area of interest. PSI ground motion rates are cross-compared with local failures and damage of involved buildings, recently recognized by in situ observations. As a result, the analysis of landslide-induced movements over almost 20 years and the validation of radar data with manufactured crack patterns, permits one to finally achieve a complete and reliable assessment in the San Fratello test site. [ABSTRACT FROM AUTHOR]

Landslide and especially rockfall hazard widely occurs along cut slopes in mountainous regions. The risk assessment of mass movements is still one of most challenging problems in slope engineering geology. We propose a routine method to assess rock slide and rockfall risk of cut slopes essentially based on slope properties and rock mass structure. The method is a lean low-cost path to a risk estimate. Rock block size is simplified into two classes, {small} with a volume less than 1.0 m and {large}, greater than 1.0 m. Studies indicate that for a slope with n small-medium rock blocks, the possibility of rockfalls can be estimated by 1 − (1 − P), in which P is the likelihood of one {small} rock block fall. The possibility of other types of mass movement can be determined by the first-order second-moment (FOSM) method. Based on this, an exponent equation was adopted to evaluate the consequence and the risk. The methodology is demonstrated by a case study from the mountains of Mentougou district, Beijing, China. Based on the investigations of geological conditions (i.e., lithology, weathering and rock mass structure) and some historical mass movement data of the cut slopes, a zonation map for rockfall and rock slide risk along a 17-km section of a road is presented. The result is supported by mass movement event observations in the recent 2 years. [ABSTRACT FROM AUTHOR]

Logistic regression studies which assess landslide susceptibility are widely available in the literature. However, a global review of these studies to synthesise and compare the results does not exist. There are currently no guidelines for the selection of covariates to be used in logistic regression analysis, and as such, the covariates selected vary widely between studies. An inventory of significant covariates associated with landsliding produced from the full set of such studies globally would be a useful aid to the selection of covariates in future logistic regression studies. Thus, studies using logistic regression for landslide susceptibility estimation published in the literature were collated, and a database was created of the significant factors affecting the generation of landslides. The database records the paper the data were taken from, the year of publication, the approximate longitude and latitude of the study area, the trigger method (where appropriate) and the most dominant type of landslides occurring in the study area. The significant and non-significant (at the 95 % confidence level) covariates were recorded, as well as their coefficient, statistical significance and unit of measurement. The most common statistically significant covariate used in landslide logistic regression was slope, followed by aspect. The significant covariates related to landsliding varied for earthquake-induced landslides compared to rainfall-induced landslides, and between landslide type. More importantly, the full range of covariates used was identified along with their frequencies of inclusion. The analysis showed that there needs to be more clarity and consistency in the methodology for selecting covariates for logistic regression analysis and in the metrics included when presenting the results. Several recommendations for future studies were given. [ABSTRACT FROM AUTHOR]

Landslides are considered a form of physical soil degradation and are concentrated, especially in southern European countries, on inland and marginal rural areas. Low-density, economically disadvantaged and poorly accessible areas are assumed to share a high landslide occurrence probability. However, an empirical verification of this assumption is still lacking for Mediterranean countries. This study investigates the spatial relation between a composite index of landslide risk and more than 100 indicators at the municipal level in Italy - a country with high landslide risk - exploring multiple territorial dimensions (population dynamics and settlements, job market and human capital, economic specialization and competitiveness, quality of life, agriculture and rural development, territory and environment). We combine nonparametric correlation, principal component analysis and hierarchical clustering, to profile municipalities according to their levels of landslide risk. The high landslide risk in certain areas of Italy is related to specific socio-economic attributes (depopulation, ageing, tourism specialization, low density of economic activities, modest participation to the job market and crime intensity) and agro-environmental features (low-intensity cropping systems, natural landscapes and water resource availability). [ABSTRACT FROM AUTHOR]