Sample records for mckinney bay landslide

  1. Landslides and tsunamis predicted by incompressible smoothed particle hydrodynamics (SPH) with application to the 1958 Lituya Bay event and idealized experiment. (United States)

    Xenakis, A M; Lind, S J; Stansby, P K; Rogers, B D


    Tsunamis caused by landslides may result in significant destruction of the surroundings with both societal and industrial impact. The 1958 Lituya Bay landslide and tsunami is a recent and well-documented terrestrial landslide generating a tsunami with a run-up of 524 m. Although recent computational techniques have shown good performance in the estimation of the run-up height, they fail to capture all the physical processes, in particular, the landslide-entry profile and interaction with the water. Smoothed particle hydrodynamics (SPH) is a versatile numerical technique for describing free-surface and multi-phase flows, particularly those that exhibit highly nonlinear deformation in landslide-generated tsunamis. In the current work, the novel multi-phase incompressible SPH method with shifting is applied to the Lituya Bay tsunami and landslide and is the first methodology able to reproduce realistically both the run-up and landslide-entry as documented in a benchmark experiment. The method is the first paper to develop a realistic implementation of the physics that in addition to the non-Newtonian rheology of the landslide includes turbulence in the water phase and soil saturation. Sensitivity to the experimental initial conditions is also considered. This work demonstrates the ability of the proposed method in modelling challenging environmental multi-phase, non-Newtonian and turbulent flows.

  2. Landslides, Floods, and Marine Effects of the Storm of January 3-5, 1982, in the San Francisco Bay Region, California (United States)

    Ellen, Stephen D.; Wieczorek, Gerald F.


    A catastrophic rainstorm in central California on January 3-5,1982, dropped as much as half the mean annual precipitation within a period of about 32 hours, triggering landslides and floods throughout 10 counties in the vicinity of the San Francisco Bay. More than 18,000 of the slides induced by the storm transformed into debris flows that swept down hillslopes or drainages with little warning. Debris flows damaged at least 100 homes, killed 14 residents, and carried a 15th victim into a creek. Shortly after rainfall ceased, more than 459,000 m3 of earth and rock slid from a mountainside above the community of Love Creek in Santa Cruz County, burying 10 people in their homes. Throughout the bay region, thousands of people vacated homes in hazardous areas, entire communities were isolated as roads were blocked, public water systems were destroyed, and power and telephone services were disrupted. Altogether, the storm damaged 6,300 homes, 1,500 businesses, and tens of kilometers of roads, bridges, and communication lines. Preliminary rough estimates of total storm damage, compiled for emergency purposes within 2 weeks of the storm, exceeded $280 million. Carefully documented direct costs from landslides exceeded $66 million; total costs from landslides certainly were greater and probably constituted a much larger proportion of the total storm damage than suggested by these disparate figures. Landslides accounted for 25 of the 33 deaths attributed to the storm.

  3. 76 FR 33777 - Stewart B. McKinney National Wildlife Refuge, Middlesex County, CT; Comprehensive Conservation... (United States)


    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R5-R-2011-N043; BAC-4311-K9-S3] Stewart B. McKinney National Wildlife Refuge, Middlesex County, CT; Comprehensive Conservation Plan and... headquarters located in Middlesex County, CT. This notice complies with our CCP policy to: (1) Advise other...

  4. Turnerellina, a new name for Turnerella Taylor & McKinney, 2006 (Bryozoa, Cheilostomata)

    NARCIS (Netherlands)

    Taylor, P.D.; McKinney, F.K.


    Turnerella Taylor & McKinney, 2006, p. 164, introduced for a new genus of cribrimorph Cheilostomata (Bryozoa), is preoccupied by Turnerella Cockerell, 1910, a genus of Hymenoptera, and two other introductions of the same name for new insect genera. We propose Turnerellina as a new name to replace

  5. Landslide Regions (United States)

    Department of Homeland Security — These data are a digital version of U.S. Geological Survey Professional Paper 1183, Landslide Overview Map of the Conterminous United States. The map and digital...

  6. Estimating the empirical probability of submarine landslide occurrence (United States)

    Geist, Eric L.; Parsons, Thomas E.; Mosher, David C.; Shipp, Craig; Moscardelli, Lorena; Chaytor, Jason D.; Baxter, Christopher D. P.; Lee, Homa J.; Urgeles, Roger


    The empirical probability for the occurrence of submarine landslides at a given location can be estimated from age dates of past landslides. In this study, tools developed to estimate earthquake probability from paleoseismic horizons are adapted to estimate submarine landslide probability. In both types of estimates, one has to account for the uncertainty associated with age-dating individual events as well as the open time intervals before and after the observed sequence of landslides. For observed sequences of submarine landslides, we typically only have the age date of the youngest event and possibly of a seismic horizon that lies below the oldest event in a landslide sequence. We use an empirical Bayes analysis based on the Poisson-Gamma conjugate prior model specifically applied to the landslide probability problem. This model assumes that landslide events as imaged in geophysical data are independent and occur in time according to a Poisson distribution characterized by a rate parameter λ. With this method, we are able to estimate the most likely value of λ and, importantly, the range of uncertainty in this estimate. Examples considered include landslide sequences observed in the Santa Barbara Channel, California, and in Port Valdez, Alaska. We confirm that given the uncertainties of age dating that landslide complexes can be treated as single events by performing statistical test of age dates representing the main failure episode of the Holocene Storegga landslide complex.

  7. Landslide Economics: Concepts and Case Studies (United States)

    Klose, Martin; Damm, Bodo


    ) disaster financing and budgetary burdens, and (iii) economic risk balancing in urban planning. The results of the conducted case studies are discussed with regard to method development for integrated assessment of landslide risk. References Crovelli, R.A., Coe, J.A., 2009. Probabilistic estimation of numbers and costs of future landslides in the San Francisco Bay region. Georisk 3, 206-223. Klose, M., Highland, L., Damm, B., Terhorst, B., 2014a. Estimation of direct landslide costs in industrialized countries: challenges, concepts, and case study. In: Sassa, K., Canuti, P., Yin, Y. (Eds.), Landslide Science for a Safer Geoenvironment. Volume 2: Methods of Landslide Studies. Springer, Berlin, pp. 661-667. Klose, M., Damm, B., Terhorst, B., 2014b. Landslide cost modeling for transportation infrastructures: a methodological approach. Landslides, DOI 10.1007/s10346-014-0481-1. Wills, C., Perez, F., Branum, D., 2014. New Method for Estimating Landslide Losses from Major Winter Storms in California and Application to the ARkStorm Scenario. Natural Hazards Review, DOI 10.1061/(ASCE)NH.1527-6996.0000142.

  8. Global Landslide Catalog Export (United States)

    National Aeronautics and Space Administration — The Global Landslide Catalog (GLC) was developed with the goal of identifying rainfall-triggered landslide events around the world, regardless of size, impacts or...

  9. Global Landslide Hazard Distribution (United States)

    National Aeronautics and Space Administration — Global Landslide Hazard Distribution is a 2.5 minute grid of global landslide and snow avalanche hazards based upon work of the Norwegian Geotechnical Institute...

  10. Experience in landslide control

    Energy Technology Data Exchange (ETDEWEB)

    Koz' min, L S


    The problems of slope stability in the Krasnoyarskugol' surface mines are discussed. Methods used for slide prevention and slide control from 1977 to 1982 are analyzed. Landslides were caused by weathering of the argillite layer in the coal seam roof. Sliding plane was parallel to the coal seam roof. At a later stage of landslide prevention sliding planes were in the coal seam floor (which consisted of weak rock layers). Range of landslides was evaluated. Losses caused by landslides were discussed: working time losses, losses of coal, damaged equipment. Landslide hazards were controlled by reducing slope angle and by changing cut geometry. Cross section of the cut with a spoil bank prone to landslides is shown in a scheme. Reducing angle of slope inclination, using strong rock layers as the spoil bank base and changing cut geometry eliminated landslides in 1982. Recommendations on landslide control in coal surface mines with layers of weak rocks influenced by weathering are made.


    Directory of Open Access Journals (Sweden)

    Dan Zarojanu


    Full Text Available In the county of Suceava, the landslides are a real and permanent problem. This paper presents the observations of landslides over the last 30 years in Suceava County, especially their morphology, theirs causes and the landslide stopping measures. It presents also several details regarding the lanslides from the town of Suceava, of Frasin and the village of Brodina.

  12. A computationally fast, reduced model for simulating landslide dynamics and tsunamis generated by landslides in natural terrains (United States)

    Mohammed, F.


    Landslide hazards such as fast-moving debris flows, slow-moving landslides, and other mass flows cause numerous fatalities, injuries, and damage. Landslide occurrences in fjords, bays, and lakes can additionally generate tsunamis with locally extremely high wave heights and runups. Two-dimensional depth-averaged models can successfully simulate the entire lifecycle of the three-dimensional landslide dynamics and tsunami propagation efficiently and accurately with the appropriate assumptions. Landslide rheology is defined using viscous fluids, visco-plastic fluids, and granular material to account for the possible landslide source materials. Saturated and unsaturated rheologies are further included to simulate debris flow, debris avalanches, mudflows, and rockslides respectively. The models are obtained by reducing the fully three-dimensional Navier-Stokes equations with the internal rheological definition of the landslide material, the water body, and appropriate scaling assumptions to obtain the depth-averaged two-dimensional models. The landslide and tsunami models are coupled to include the interaction between the landslide and the water body for tsunami generation. The reduced models are solved numerically with a fast semi-implicit finite-volume, shock-capturing based algorithm. The well-balanced, positivity preserving algorithm accurately accounts for wet-dry interface transition for the landslide runout, landslide-water body interface, and the tsunami wave flooding on land. The models are implemented as a General-Purpose computing on Graphics Processing Unit-based (GPGPU) suite of models, either coupled or run independently within the suite. The GPGPU implementation provides up to 1000 times speedup over a CPU-based serial computation. This enables simulations of multiple scenarios of hazard realizations that provides a basis for a probabilistic hazard assessment. The models have been successfully validated against experiments, past studies, and field data

  13. Hydrologic Controls on Shallow Landslide Location, Size, and Shape (United States)

    Bellugi, D.; Milledge, D.; Perron, T.; McKean, J. A.; Dietrich, W.; Rulli, M.


    Shallow landslides, typically involving just the soil mantle, are principally controlled by topography, soil and root strengths, and soil thickness, and are typically triggered by storm-induced increases in pore water pressure. The response of a landscape to landslide-triggering storms will thus depend on factors such as rainfall totals, storm intensity and duration, and antecedent moisture conditions. The two dominant mechanisms that generate high pore water pressures at a point are topographically-steered lateral subsurface flow (over timescales of days to weeks), and rapid vertical infiltration (over timescales of minutes to hours). We aim to understand the impact of different storm characteristics and hydrologic regimes on shallow landslide location, size, and shape. We have developed a regional-scale model, which applies a low-parameter grid-based multi-dimensional slope stability model within a novel search algorithm, to generate discrete landslide predictions. This model shows that the spatial organization of parameters such as root strength and pore water pressure has a strong control on shallow landslide location, size, and shape. We apply this model to a field site near Coos Bay, OR, where a ten-year landslide inventory has been mapped onto high-resolution topographic data. Our model predicts landslide size generally increases with increasing rainfall intensity, except when root strength is extremely high and pore pressures are topographically steered. The distribution of topographic index values (the ratios of contributing area to slope) of predicted landslides is a clear signature of the pore water pressure generation mechanism: as laterally dominated flow increases, landslides develop in locations with lower slopes and higher contributing areas; in contrast, in the case of vertically-dominated pore pressure rise, landslides are consistently found in locations with higher slopes and lower contributing areas. While in both cases landslides are found in

  14. Assessing landslide exposure in areas with limited landslide information

    NARCIS (Netherlands)

    Pellicani, R.; van Westen, C.J.; Spilotro, G.


    Landslide risk assessment is often a difficult task due to the lack of temporal data on landslides and triggering events (frequency), run-out distance, landslide magnitude and vulnerability. The probability of occurrence of landslides is often very difficult to predict, as well as the expected

  15. Landslides of Palestinian Region (United States)

    Alwahsh, H.


    Natural disasters are extreme sudden events caused by environmental and natural actors that take away the lives of many thousands of people each year and damage large amount of properties. They strike anywhere on earth, often without any warning. A risk maps of natural disaster are very useful to identify the places that might be adversely affected in the event of natural disaster. The earthquakes are one of natural disaster that have the greatest hazards and will cause loss of life and properties due to damaging the structures of building, dams, bridges. In addition, it will affect local geology and soil conditions. The site effects play an important role in earthquake risk because of its amplification or damping simulation. Another parameter in developing risk map is landslide, which is also one of the most important topics in site effect hazards. Palestine region has been suffering landslide hazards because of the topographical and geological conditions of this region. Most Palestine consists of mountainous area, which has great steep slopes and the type of soil is mainly grayish to yellowish silty clay (Marl Soil). Due to the above mentioned factors many landslides have been occurred from Negev south to the northern borders of Palestine. An example of huge and destruction landslide in a Palestine authority is the landslide in the White Mountain area in the city of Nablus, which occurred in 1997. The geotechnical and geophysical investigation as well as slope stability analysis should be considered in making landslide maps that are necessary to develop risk levels of the natural disaster. Landslides occurred in slopes that are created naturally or by human beings. Failure of soil mass occurs, and hence landslide of soil mass happen due to sliding of soil mass along a plane or curved surface. In general, the slopes become unstable when the shear stresses (driving force) generated in the soil mass exceed the available shearing resistance on the rupture surface

  16. Vulnerability assessment for reinforced concrete buildings exposed to landslides

    International Nuclear Information System (INIS)

    Mavrouli, O.; Corominas, J.; Fotopoulou, S.; Pitilakis, K.; Zuccaro, G.; Cacace, F.; De Gregorio, D.; Santo, A.; Di Crescenzo, G.; Foerster, E.; Ulrich, T.


    The methodologies available for the analytical quantification of the vulnerability of buildings which are subject to actions resulting from slope instabilities and landslides are relatively limited in comparison with other components of quantitative landslide risk assessment. This paper provides a general methodology for calculating the vulnerabilities of reinforced concrete frame structures that are subject to three types of slope instability: slow-moving landslides, rapid flow-type slides and rock falls. The vulnerability is expressed using sets of fragility curves. A description of the general framework and of the specialised procedures employed is presented here, separately for each landslide mechanism, through the example of a single-bay one-storey reinforced concrete frame. The properties of the frame are taken into account as variables with associated uncertainties. The derived vulnerability curves presented here can be used directly by risk assessment practitioners without having to repeat the procedure, given the expected range of landslide intensities and for similar building typologies and ranges of structural characteristics. This permits the applicability of the calculated vulnerability to a wide variety of similar frames for a range of landslide intensity parameters. (authors)

  17. Tsunamis generated by unconfined deformable granular landslides in various topographic configurations (United States)

    McFall, B. C.; Mohammed, F.; Fritz, H. M.


    Tsunamis generated by landslides and volcanic island collapses account for some of the most catastrophic events. Major tsunamis caused by landslides or volcanic island collapse were recorded at Krakatoa in 1883, Grand Banks, Newfoundland in 1929, Lituya Bay, Alaska in 1958, Papua New Guinea in 1998, and Java in 2006. Source and runup scenarios based on real world events are physically modeled in the three dimensional NEES tsunami wave basin (TWB) at Oregon State University (OSU). A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. The LTG consists of a sliding box filled with up to 1,350 kg of naturally rounded river gravel which is accelerated by means of four pneumatic pistons down the 2H: 1V slope, launching the granular landslide towards the water at velocities of up to 5 m/s. Topographical and bathymetric features can greatly affect wave characteristics and runup heights. Landslide tsunamis are studied in different topographic and bathymetric configurations: far field propagation and runup, a narrow fjord and curved headland configurations, and a conical island setting representing landslides off an island or a volcanic flank collapse. Water surface elevations were measured using an array of resistance wave gauges. The granulate landslide width, thickness and front velocity were measured using above and underwater cameras. Landslide 3-dimensional surface reconstruction and surface velocity properties were measured using a stereo particle image velocimetry (PIV) setup. The speckled pattern on the surface of the granular landslide allows for cross-correlation based PIV analysis. Wave runup was measured with resistance wave gauges along the slope and verified with video image processing. The measured landslide and tsunami data serve to validate and advance 3-dimensional numerical landslide tsunami and prediction models.

  18. Landslides - Cause and effect (United States)

    Radbruch-Hall, D. H.; Varnes, D.J.


    Landslides can cause seismic disturbances; landslides can also result from seismic disturbances, and earthquake-induced slides have caused loss of life in many countries. Slides can cause disastrous flooding, particularly when landslide dams across streams are breached, and flooding may trigger slides. Slope movement in general is a major process of the geologic environment that places constraints on engineering development. In order to understand and foresee both the causes and effects of slope movement, studies must be made on a regional scale, at individual sites, and in the laboratory. Areal studies - some embracing entire countries - have shown that certain geologic conditions on slopes facilitate landsliding; these conditions include intensely sheared rocks; poorly consolidated, fine-grained clastic rocks; hard fractured rocks underlain by less resistant rocks; or loose accumulations of fine-grained surface debris. Field investigations as well as mathematical- and physical-model studies are increasing our understanding of the mechanism of slope movement in fractured rock, and assist in arriving at practical solutions to landslide problems related to all kinds of land development for human use. Progressive failure of slopes has been studied in both soil and rock mechanics. New procedures have been developed to evaluate earthquake response of embankments and slopes. The finite element method of analysis is being extensively used in the calculation of slope stability in rock broken by joints, faults, and other discontinuities. ?? 1976 International Association of Engineering Geology.

  19. Tsunami Generation and Propagation by 3D deformable Landslides and Application to Scenarios (United States)

    McFall, Brian C.; Fritz, Hermann M.


    Tsunamis generated by landslides and volcano flank collapse account for some of the most catastrophic natural disasters recorded and can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. The bathymetric and topographic scenarios tested with the LTG are the basin-wide propagation and runup, fjord, curved headland fjord and a conical island setting representing a landslide off an island or a volcano flank collapse. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1 landslides to study the granulometry effects: naturally rounded river gravel and cobble mixtures. Water surface elevations are recorded by an array of resistance wave gauges. The landslide deformation is measured from above and underwater camera recordings. The landslide deposit is measured on the basin floor with a multiple transducer acoustic array (MTA). Landslide surface reconstruction and kinematics are determined with a stereo particle image velocimetry (PIV) system. Wave runup is recorded with resistance wave gauges along the slope and verified

  20. Landslide prediction system for rainfall induced landslides in Slovenia (Masprem

    Directory of Open Access Journals (Sweden)

    Mateja Jemec Auflič


    Full Text Available In this paper we introduce a landslide prediction system for modelling the probabilities of landslides through time in Slovenia (Masprem. The system to forecast rainfall induced landslides is based on the landslide susceptibility map, landslide triggering rainfall threshold values and the precipitation forecasting model. Through the integrated parameters a detailed framework of the system, from conceptual to operational phases, is shown. Using fuzzy logic the landslide prediction is calculated. Potential landslide areas are forecasted on a national scale (1: 250,000 and on a local scale (1: 25,000 for fie selected municipalities where the exposure of inhabitants, buildings and different type of infrastructure is displayed, twice daily. Due to different rainfall patterns that govern landslide occurrences, the system for landslide prediction considers two different rainfall scenarios (M1 and M2. The landslides predicted by the two models are compared with a landslide inventory to validate the outputs. In this study we highlight the rainfall event that lasted from the 9th to the 14th of September 2014 when abundant precipitation triggered over 800 slope failures around Slovenia and caused large material damage. Results show that antecedent rainfall plays an important role, according to the comparisons of the model (M1 where antecedent rainfall is not considered. Although in general the landslides areas are over-predicted and largely do not correspond to the landslide inventory, the overall performance indicates that the system is able to capture the crucial factors in determining the landslide location. Additional calibration of input parameters and the landslide inventory as well as improved spatially distributed rainfall forecast data can further enhance the model's prediction.

  1. Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California (United States)

    Pike, Richard J.; Graymer, Russell W.


    With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven

  2. Application of radioisotopes in investigating landslides

    International Nuclear Information System (INIS)

    Turcek, P.; Ravinger, R.; Hulla, J.


    Radiotracer techniques have been used for geological investigations of landslide areas. It was possible to localize a landslide area and a weakened zone. Based on the results forecasts have been made of further possible landslide in the area

  3. Landsliding in partially saturated materials (United States)

    Godt, J.W.; Baum, R.L.; Lu, N.


    [1] Rainfall-induced landslides are pervasive in hillslope environments around the world and among the most costly and deadly natural hazards. However, capturing their occurrence with scientific instrumentation in a natural setting is extremely rare. The prevailing thinking on landslide initiation, particularly for those landslides that occur under intense precipitation, is that the failure surface is saturated and has positive pore-water pressures acting on it. Most analytic methods used for landslide hazard assessment are based on the above perception and assume that the failure surface is located beneath a water table. By monitoring the pore water and soil suction response to rainfall, we observed shallow landslide occurrence under partially saturated conditions for the first time in a natural setting. We show that the partially saturated shallow landslide at this site is predictable using measured soil suction and water content and a novel unified effective stress concept for partially saturated earth materials. Copyright 2009 by the American Geophysical Union.

  4. The National Landslide Information Center; data to reduce landslide damage (United States)

    Brown, W. M.


    Almost every day a landslide disasters occurs somewhere in the world. Nearly any time there is heavy rainfall, an earthquake, a volcanic eruption, strong wave action on a shoreline, or some ill-considered alteration of sloping land by humans, landslides occur.

  5. On the characteristics of landslide tsunamis. (United States)

    Løvholt, F; Pedersen, G; Harbitz, C B; Glimsdal, S; Kim, J


    This review presents modelling techniques and processes that govern landslide tsunami generation, with emphasis on tsunamis induced by fully submerged landslides. The analysis focuses on a set of representative examples in simplified geometries demonstrating the main kinematic landslide parameters influencing initial tsunami amplitudes and wavelengths. Scaling relations from laboratory experiments for subaerial landslide tsunamis are also briefly reviewed. It is found that the landslide acceleration determines the initial tsunami elevation for translational landslides, while the landslide velocity is more important for impulsive events such as rapid slumps and subaerial landslides. Retrogressive effects stretch the tsunami, and in certain cases produce enlarged amplitudes due to positive interference. In an example involving a deformable landslide, it is found that the landslide deformation has only a weak influence on tsunamigenesis. However, more research is needed to determine how landslide flow processes that involve strong deformation and long run-out determine tsunami generation. © 2015 The Authors.

  6. Physical Modeling of Tsunamis Generated By 3D Deformable Landslides in Various Scenarios From Fjords to Conical Islands (United States)

    McFall, B. C.; Fritz, H. M.


    Tsunamis generated by landslides and volcano flank collapse can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. Two different materials are used to simulate landslides to study the granulometry effects: naturally rounded river gravel and cobble mixtures. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1 landslide off an island or a volcano flank collapse. Water surface elevations are recorded by an array of resistance wave gauges. The landslide deformation is measured from above and underwater camera recordings. The landslide deposit is measured on the basin floor with a multiple transducer acoustic array (MTA). Landslide surface reconstruction and kinematics are determined with a stereo particle image velocimetry (PIV) system. Wave runup is recorded with resistance wave gauges along the slope and verified with video image processing. The measured landslide and wave parameters are


    Directory of Open Access Journals (Sweden)

    Charles L. Mader


    Full Text Available Lituya Bay, Alaska is a T-Shaped bay, 7 miles long and up to 2 miles wide. The two arms at the head of the bay, Gilbert and Crillon Inlets, are part of a trench along the Fairweather Fault. On July 8, 1958, an 7.5 Magnitude earthquake occurred along the Fairweather fault with an epicenter near Lituya Bay.A mega-tsunami wave was generated that washed out trees to a maximum altitude of 520 meters at the entrance of Gilbert Inlet. Much of the rest of the shoreline of the Bay was denuded by the tsunami from 30 to 200 meters altitude.In the previous study it was determined that if the 520 meter high run-up was 50 to 100 meters thick, the observed inundation in the rest of Lituya Bay could be numerically reproduced. It was also concluded that further studies would require full Navier-Stokes modeling similar to those required for asteroid generated tsunami waves.During the Summer of 2000, Hermann Fritz conducted experiments that reproduced the Lituya Bay 1958 event. The laboratory experiments indicated that the 1958 Lituya Bay 524 meter run-up on the spur ridge of Gilbert Inlet could be caused by a landslide impact.The Lituya Bay impact landslide generated tsunami was modeled with the full Navier- Stokes AMR Eulerian compressible hydrodynamic code called SAGE with includes the effect of gravity.

  8. A satellite-based global landslide model

    Directory of Open Access Journals (Sweden)

    A. Farahmand


    Full Text Available Landslides are devastating phenomena that cause huge damage around the world. This paper presents a quasi-global landslide model derived using satellite precipitation data, land-use land cover maps, and 250 m topography information. This suggested landslide model is based on the Support Vector Machines (SVM, a machine learning algorithm. The National Aeronautics and Space Administration (NASA Goddard Space Flight Center (GSFC landslide inventory data is used as observations and reference data. In all, 70% of the data are used for model development and training, whereas 30% are used for validation and verification. The results of 100 random subsamples of available landslide observations revealed that the suggested landslide model can predict historical landslides reliably. The average error of 100 iterations of landslide prediction is estimated to be approximately 7%, while approximately 2% false landslide events are observed.

  9. Landslides in West Coast Metropolitan Areas: The Role of Extreme Weather Events (United States)

    Biasutti, Michela; Seager, Richard; Kirschbaum, Dalia B.


    Rainfall-induced landslides represent a pervasive issue in areas where extreme rainfall intersects complex terrain. A farsighted management of landslide risk requires assessing how landslide hazard will change in coming decades and thus requires, inter alia, that we understand what rainfall events are most likely to trigger landslides and how global warming will affect the frequency of such weather events. We take advantage of 9 years of landslide occurrence data compiled by collating Google news reports and of a high-resolution satellite-based daily rainfall data to investigate what weather triggers landslide along the West Coast US. We show that, while this landslide compilation cannot provide consistent and widespread monitoring everywhere, it captures enough of the events in the major urban areas that it can be used to identify the relevant relationships between landslides and rainfall events in Puget Sound, the Bay Area, and greater Los Angeles. In all these regions, days that recorded landslides have rainfall distributions that are skewed away from dry and low-rainfall accumulations and towards heavy intensities. However, large daily accumulation is the main driver of enhanced hazard of landslides only in Puget Sound. There, landslide are often clustered in space and time and major events are primarily driven by synoptic scale variability, namely "atmospheric rivers" of high humidity air hitting anywhere along the West Coast, and the interaction of frontal system with the coastal orography. The relationship between landslide occurrences and daily rainfall is less robust in California, where antecedent precipitation (in the case of the Bay area) and the peak intensity of localized downpours at sub-daily time scales (in the case of Los Angeles) are key factors not captured by the same-day accumulations. Accordingly, we suggest that the assessment of future changes in landslide hazard for the entire the West Coast requires consideration of future changes in the

  10. Landslide triggering by rain infiltration (United States)

    Iverson, Richard M.


    Landsliding in response to rainfall involves physical processes that operate on disparate timescales. Relationships between these timescales guide development of a mathematical model that uses reduced forms of Richards equation to evaluate effects of rainfall infiltration on landslide occurrence, timing, depth, and acceleration in diverse situations. The longest pertinent timescale is A/D0, where D0 is the maximum hydraulic diffusivity of the soil and A is the catchment area that potentially affects groundwater pressures at a prospective landslide slip surface location with areal coordinates x, y and depth H. Times greater than A/D0 are necessary for establishment of steady background water pressures that develop at (x, y, H) in response to rainfall averaged over periods that commonly range from days to many decades. These steady groundwater pressures influence the propensity for landsliding at (x, y, H), but they do not trigger slope failure. Failure results from rainfall over a typically shorter timescale H2/D0 associated with transient pore pressure transmission during and following storms. Commonly, this timescale ranges from minutes to months. The shortest timescale affecting landslide responses to rainfall is √(H/g), where g is the magnitude of gravitational acceleration. Postfailure landslide motion occurs on this timescale, which indicates that the thinnest landslides accelerate most quickly if all other factors are constant. Effects of hydrologic processes on landslide processes across these diverse timescales are encapsulated by a response function, R(t*) = √(t*/π) exp (-1/t*) - erfc (1/√t*), which depends only on normalized time, t*. Use of R(t*) in conjunction with topographic data, rainfall intensity and duration information, an infinite-slope failure criterion, and Newton's second law predicts the timing, depth, and acceleration of rainfall-triggered landslides. Data from contrasting landslides that exhibit rapid, shallow

  11. Spatiotemporal Patterns of Precipitation-Modulated Landslide Deformation From Independent Component Analysis of InSAR Time Series (United States)

    Cohen-Waeber, J.; Bürgmann, R.; Chaussard, E.; Giannico, C.; Ferretti, A.


    Long-term landslide deformation is disruptive and costly in urbanized environments. We rely on TerraSAR-X satellite images (2009-2014) and an improved data processing algorithm (SqueeSAR™) to produce an exceptionally dense Interferometric Synthetic Aperture Radar ground deformation time series for the San Francisco East Bay Hills. Independent and principal component analyses of the time series reveal four distinct spatial and temporal surface deformation patterns in the area around Blakemont landslide, which we relate to different geomechanical processes. Two components of time-dependent landslide deformation isolate continuous motion and motion driven by precipitation-modulated pore pressure changes controlled by annual seasonal cycles and multiyear drought conditions. Two components capturing more widespread seasonal deformation separate precipitation-modulated soil swelling from annual cycles that may be related to groundwater level changes and thermal expansion of buildings. High-resolution characterization of landslide response to precipitation is a first step toward improved hazard forecasting.

  12. Global Landslide Total Economic Loss Risk Deciles (United States)

    National Aeronautics and Space Administration — Global Landslide Total Economic Loss Risk Deciles is a 2.5 minute grid of global landslide total economic loss risks. A process of spatially allocating Gross...

  13. Dendrogeomorphology in landslide analysis: State of art

    Energy Technology Data Exchange (ETDEWEB)

    Margottini, C [ENEA, Casaccia (Italy). Area Energia Ambiente e Salute; Fantucci, R


    This article summarizes the uses of dendrogeomorphological techniques in landslide analysis. It shows how to study different landslides events through the analysis of living trees. Living trees record any slope inclination variation as if they were natural inclinometers moreover they can be used to date landslide and their stabilization process with time.

  14. The landslide problem

    Directory of Open Access Journals (Sweden)

    G. Shanmugam


    Full Text Available The synonymous use of the general term “landslide”, with a built-in reference to a sliding motion, for all varieties of mass-transport deposits (MTD, which include slides, slumps, debrites, topples, creeps, debris avalanches etc. in subaerial, sublacustrine, submarine, and extraterrestrial environments has created a multitude of conceptual and nomenclatural problems. In addition, concepts of triggers and long-runout mechanisms of mass movements are loosely applied without rigor. These problems have enormous implications for studies in process sedimentology, sequence stratigraphy, palaeogeography, petroleum geology, and engineering geology. Therefore, the objective of this critical review is to identify key problems and to provide conceptual clarity and possible solutions. Specific issues are the following: (1 According to “limit equilibrium analyses” in soil mechanics, sediment failure with a sliding motion is initiated over a shear surface when the factor of safety for slope stability (F is less than 1. However, the term landslide is not meaningful for debris flows with a flowing motion. (2 Sliding motion can be measured in oriented core and outcrop, but such measurement is not practical on seismic profiles or radar images. (3 Although 79 MTD types exist in the geological and engineering literature, only slides, slumps, and debrites are viable depositional facies for interpreting ancient stratigraphic records. (4 The use of the term landslide for highvelocity debris avalanches is inappropriate because velocities of mass-transport processes cannot be determined in the rock record. (5 Of the 21 potential triggering mechanisms of sediment failures, frequent short-term events that last for only a few minutes to several hours or days (e.g., earthquakes, meteorite impacts, tsunamis, tropical cyclones, etc. are more relevant in controlling deposition of deep-water sands than sporadic long-term events that last for thousands to millions of

  15. Landslide Hazard in Georgia (United States)

    Gaprindashvili, George; Tsereteli, Emil; Gaprindashvili, Merab


    In the last decades of the XX century, protect the population from geological hazards, to maintain land and safe operation of the engineering facilities has become the most important social - economic, demographic, political and environmental problems for the whole world. Georgia, with its scales of origination of the natural-catastrophic processes (landslide, mudflow, rockfall, erosion and etc.), their re-occurrence and with the negative results inflicted by these processes to the population, agricultural lands and engineering objects, is one of the most complex mountainous region. The extremely sensitive conditions were conditioned by: 1. Activation of highly intense earthquakes; 2. Activation of the negative meteorological events provoking the disaster processes on the background of global climatic changes and their abnormally frequent occurrence (mostly increased atmospheric precipitations, temperature and humidity); 3. Large-scale Human impact on the environment. Following the problem urgency, a number of departmental and research institutions have made their operations more intense in the given direction within the limits of their competence. First of all, the activity of the Department of Geology of Georgia (which is at present included in the National Environmental Agency of the Ministry of Environment and Natural Resources Protection), which mapped, identified and cataloged the hazardous processes on the territory of the country and identified the spatial limits and developmental regularities of these processes for tens of years. The increased risk of Geological catastrophes in Georgia first of all is caused by insufficient information between society and responsible persons toward this event. The existed situation needs the base assessment of natural disasters level, the identification of events, to determine their caused reasons, to develop special maps in GIS system, and continuous functioning of geo monitoring researches for develop safety early

  16. A landslide susceptibility map of Africa (United States)

    Broeckx, Jente; Vanmaercke, Matthias; Duchateau, Rica; Poesen, Jean


    Studies on landslide risks and fatalities indicate that landslides are a global threat to humans, infrastructure and the environment, certainly in Africa. Nonetheless our understanding of the spatial patterns of landslides and rockfalls on this continent is very limited. Also in global landslide susceptibility maps, Africa is mostly underrepresented in the inventories used to construct these maps. As a result, predicted landslide susceptibilities remain subject to very large uncertainties. This research aims to produce a first continent-wide landslide susceptibility map for Africa, calibrated with a well-distributed landslide dataset. As a first step, we compiled all available landslide inventories for Africa. This data was supplemented by additional landslide mapping with Google Earth in underrepresented regions. This way, we compiled 60 landslide inventories from the literature (ca. 11000 landslides) and an additional 6500 landslides through mapping in Google Earth (including 1500 rockfalls). Various environmental variables such as slope, lithology, soil characteristics, land use, precipitation and seismic activity, were investigated for their significance in explaining the observed spatial patterns of landslides. To account for potential mapping biases in our dataset, we used Monte Carlo simulations that selected different subsets of mapped landslides, tested the significance of the considered environmental variables and evaluated the performance of the fitted multiple logistic regression model against another subset of mapped landslides. Based on these analyses, we constructed two landslide susceptibility maps for Africa: one for all landslide types and one excluding rockfalls. In both maps, topography, lithology and seismic activity were the most significant variables. The latter factor may be surprising, given the overall limited degree of seismicity in Africa. However, its significance indicates that frequent seismic events may serve as in important

  17. Mining Input Data for Multivariate Probabilistic Modeling of Rainfall-Induced Landslide Hazard in the Lake ATITLÁN Watershed in Guatemala (United States)

    Cobin, P. F.; Oommen, T.; Gierke, J. S.


    The Lake Atitlán watershed is home to approximately 200,000 people and is located in the western highlands of Guatemala. Steep slopes, highly susceptible to landslides during the rainy season, characterize the region. Typically these landslides occur during high-intensity precipitation events. Hurricane Stan hit Guatemala in October 2005; the resulting flooding and landslides devastated the region. Locations of landslide and non-landslide points were obtained from field observations and orthophotos taken following Hurricane Stan. Different datasets of landslide and non-landslide points across the watershed were used to compare model success at a small scale and regional scale. This study used data from multiple attributes: geology, geomorphology, distance to faults and streams, land use, slope, aspect, curvature, plan curvature, profile curvature and topographic wetness index. The open source software Weka was used for the data mining. Several attribute selection methods were applied to the data to predetermine the potential landslide causative influence. Different multivariate algorithms were then evaluated for their ability to predict landslide occurrence. The following statistical parameters were used to evaluate model accuracy: precision, recall, F measure and area under the receiver operating characteristic (ROC) curve. The attribute combinations of the most successful models were compared to the attribute evaluator results. The algorithm BayesNet yielded the most accurate model and was used to build a probability map of landslide initiation points for the regions selected in the watershed. The ultimate aim of this study is to share the methodology and results with municipal contacts from the author's time as a U.S. Peace Corps volunteer, to facilitate more effective future landslide hazard planning and mitigation.

  18. Directions of the US Geological Survey Landslide Hazards Reduction Program (United States)

    Wieczorek, G.F.


    The US Geological Survey (USGS) Landslide Hazards Reduction Program includes studies of landslide process and prediction, landslide susceptibility and risk mapping, landslide recurrence and slope evolution, and research application and technology transfer. Studies of landslide processes have been recently conducted in Virginia, Utah, California, Alaska, and Hawaii, Landslide susceptibility maps provide a very important tool for landslide hazard reduction. The effects of engineering-geologic characteristics of rocks, seismic activity, short and long-term climatic change on landslide recurrence are under study. Detailed measurement of movement and deformation has begun on some active landslides. -from Author

  19. Landslide databases for applied landslide impact research: the example of the landslide database for the Federal Republic of Germany (United States)

    Damm, Bodo; Klose, Martin


    This contribution presents an initiative to develop a national landslide database for the Federal Republic of Germany. It highlights structure and contents of the landslide database and outlines its major data sources and the strategy of information retrieval. Furthermore, the contribution exemplifies the database potentials in applied landslide impact research, including statistics of landslide damage, repair, and mitigation. The landslide database offers due to systematic regional data compilation a differentiated data pool of more than 5,000 data sets and over 13,000 single data files. It dates back to 1137 AD and covers landslide sites throughout Germany. In seven main data blocks, the landslide database stores besides information on landslide types, dimensions, and processes, additional data on soil and bedrock properties, geomorphometry, and climatic or other major triggering events. A peculiarity of this landslide database is its storage of data sets on land use effects, damage impacts, hazard mitigation, and landslide costs. Compilation of landslide data is based on a two-tier strategy of data collection. The first step of information retrieval includes systematic web content mining and exploration of online archives of emergency agencies, fire and police departments, and news organizations. Using web and RSS feeds and soon also a focused web crawler, this enables effective nationwide data collection for recent landslides. On the basis of this information, in-depth data mining is performed to deepen and diversify the data pool in key landslide areas. This enables to gather detailed landslide information from, amongst others, agency records, geotechnical reports, climate statistics, maps, and satellite imagery. Landslide data is extracted from these information sources using a mix of methods, including statistical techniques, imagery analysis, and qualitative text interpretation. The landslide database is currently migrated to a spatial database system

  20. Spatial prediction of landslides using a hybrid machine learning approach based on Random Subspace and Classification and Regression Trees (United States)

    Pham, Binh Thai; Prakash, Indra; Tien Bui, Dieu


    A hybrid machine learning approach of Random Subspace (RSS) and Classification And Regression Trees (CART) is proposed to develop a model named RSSCART for spatial prediction of landslides. This model is a combination of the RSS method which is known as an efficient ensemble technique and the CART which is a state of the art classifier. The Luc Yen district of Yen Bai province, a prominent landslide prone area of Viet Nam, was selected for the model development. Performance of the RSSCART model was evaluated through the Receiver Operating Characteristic (ROC) curve, statistical analysis methods, and the Chi Square test. Results were compared with other benchmark landslide models namely Support Vector Machines (SVM), single CART, Naïve Bayes Trees (NBT), and Logistic Regression (LR). In the development of model, ten important landslide affecting factors related with geomorphology, geology and geo-environment were considered namely slope angles, elevation, slope aspect, curvature, lithology, distance to faults, distance to rivers, distance to roads, and rainfall. Performance of the RSSCART model (AUC = 0.841) is the best compared with other popular landslide models namely SVM (0.835), single CART (0.822), NBT (0.821), and LR (0.723). These results indicate that performance of the RSSCART is a promising method for spatial landslide prediction.

  1. Do landslides follow landslides? Insights in path dependency from a multi-temporal landslide inventory

    NARCIS (Netherlands)

    Samia, Jalal; Temme, Arnaud; Bregt, Arnold; Wallinga, Jakob; Guzzetti, Fausto; Ardizzone, Francesca; Rossi, Mauro


    Landslides are a major category of natural disasters, causing loss of lives, livelihoods and property. The critical roles played by triggering (such as extreme rainfall and earthquakes), and intrinsic factors (such as slope steepness, soil properties and lithology) have previously successfully

  2. Mex Bay

    African Journals Online (AJOL)



    Feb 23, 2015 ... surveys to assess the vulnerability of the most important physical and eutrophication parameters along. El- Mex Bay coast. As a result of increasing population and industrial development, poorly untreated industrial waste, domestic sewage, shipping industry and agricultural runoff are being released to the.

  3. Landslide Catastrophes and Disaster Risk Reduction: A GIS Framework for Landslide Prevention and Management

    Directory of Open Access Journals (Sweden)

    Xin Wang


    Full Text Available As catastrophic phenomena, landslides often cause large-scale socio-economic destruction including loss of life, economic collapse, and human injury. In addition, landslides can impair the functioning of critical infrastructure and destroy cultural heritage and ecological systems. In order to build a more landslide resistant and resilient society, an original GIS-based decision support system is put forth in order to help emergency managers better prepare for and respond to landslide disasters. The GIS-based landslide monitoring and management system includes a Central Repository System (CRS, Disaster Data Processing Modules (DDPM, a Command and Control System (CCS and a Portal Management System (PMS. This architecture provides valuable insights into landslide early warning, landslide risk and vulnerability analyses, and critical infrastructure damage assessments. Finally, internet-based communications are used to support landslide disaster modelling, monitoring and management.

  4. Landslide susceptibility zonation in part of Tehri reservoir region

    Indian Academy of Sciences (India)

    Fuzzy logic; landslide susceptibility; frequency ratio. ... zones using landslide frequency ratio and fuzzy logic in GIS environment is presented for Tehri ... Temporal remote sensing data was used to prepare important landslide causative factor ...

  5. Landslides Hazard Assessment Using Different Approaches

    Directory of Open Access Journals (Sweden)

    Coman Cristina


    Full Text Available Romania represents one of Europe’s countries with high landslides occurrence frequency. Landslide hazard maps are designed by considering the interaction of several factors which, by their joint action may affect the equilibrium state of the natural slopes. The aim of this paper is landslides hazard assessment using the methodology provided by the Romanian national legislation and a very largely used statistical method. The final results of these two analyses are quantitative or semi-quantitative landslides hazard maps, created in geographic information system environment. The data base used for this purpose includes: geological and hydrogeological data, digital terrain model, hydrological data, land use, seismic action, anthropic action and an inventory of active landslides. The GIS landslides hazard models were built for the geographical area of the Iasi city, located in the north-east side of Romania.

  6. Landslide hazard and risk assessment using semi-automatically created landslide inventories

    NARCIS (Netherlands)

    Martinez, J.A.; van Westen, C.J.; Kerle, N.; Jetten, V.G.; Kumar, K.V.


    Landslide inventories prepared manually from remote sensing data or through field surveys have shown to be useful for preparation of landslide susceptibility and hazard maps. Recent literatures show several studies have been carried out to prepare landslide inventories from satellite data by

  7. Landslide/reservoir interaction: 3D numerical modelling of the Vajont rockslide and generated water wave (United States)

    Crosta, G.; Imposimato, S.; Roddeman, D.; Frattini, P.


    Fast moving landslides can be originated along slopes in mountainous terrains with natural and artificial lakes, or fjords at the slope foot. This landslides can reach extremely high speed and the impact with the immobile reservoir water can be influenced by the local topography and the landslide mass profile. The impact can generate large impulse waves and landslide tsunami. Initiation, propagation and runup are the three phases that need to be considered. The landslide evolution and the consequent wave can be controlled by the initial mass position (subaerial, partially or completely submerged), the landslide speed, the type of material, the subaerial and subaqueous slope geometry, the landslide depth and length at the impact, and the water depth. Extreme events have been caused by subaerial landslides: the 1963 Vajont rockslide (Italy), the 1958 Lituya Bay event (Alaska), the Tafjord and the Loen multiple events event (Norway), also from volcanic collapses (Hawaii and Canary islands). Various researchers completed a systematic experimental work on 2D and 3D wave generation and propagation (Kamphuis and Bowering, 1970; Huber, 1980; Müller, 1995; Huber and Hager, 1997; Fritz, 2002; Zweifel, 2004; Panizzo et al., 2005; Heller, 2007; Heller and Kinnear, 2010; Sælevik et al., 2009), using both rigid blocks and deformable granular" masses. Model data and results have been used to calibrate and validate numerical modelling tools (Harbitz, 1992; Jiang and LeBlond, 1993; Grilli et al., 2002; Grilli and Watts, 2005; Lynett and Liu, 2005; Tinti et al., 2006; Abadie et al., 2010) generally considering simplified rheologies (e.g. viscous rheologies) for subaerial subaqueous spreading. We use a FEM code (Roddeman, 2011; Crosta et al., 2006, 2009, 2010, 2011) adopting an Eulerian-Lagrangian approach to give accurate results for large deformations. We model both 2D and fully 3D events considering different settings. The material is considered as a fully deformable elasto

  8. Real Estate Development at Landslides

    Directory of Open Access Journals (Sweden)

    Hakan Kaya


    Full Text Available The desire to grow and develop at a fast pace without regard for scientific conditions is an obsession, particularly of developing countries like Turkey. However, any development achieved in ignorance of the scientific process and sustainability leads to higher costs as well as serious losses in terms of human and other life. Our area of study is one of the best examples of the negative effects of this type of development. The area under study covers the landslide sites located on the southwest of Istanbul (the Büyükçekmece, Beylikdüzü, Avcılar and Esenyurt districts which is the largest city in Turkey. In this study, we tried to probe into the real estate development process of the landslide sites, the measures taken or failed to be taken in this process, the humanitarian and economic conditions involved and the things required to be done.

  9. Landslide in claystone derived soil

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, A M


    This article describes a landslide that occured in the Pittsburgh area in a soil deposit derived from the Pittsburgh Redbed Claystone when a cut was made at the toe. (The Pittsburgh Redbed Claystone is the parent of much of the soil material involved in the Pittsburgh area and occurs about mid way between the base of Pittsburgh Coal and the top of the Upper Freepost Coal). The topography before the slide was known and the geometry of the slide mass was established. Slope stability analysis indicated that the landslide could have been predicted using effective stress-shear-strength parameters of s of 12 to 13 and c is 0, where s is angle of shearing resistance and c is cohesion intercept in terms of effective stresses.

  10. Quick clay and landslides of clayey soils. (United States)

    Khaldoun, Asmae; Moller, Peder; Fall, Abdoulaye; Wegdam, Gerard; De Leeuw, Bert; Méheust, Yves; Otto Fossum, Jon; Bonn, Daniel


    We study the rheology of quick clay, an unstable soil responsible for many landslides. We show that above a critical stress the material starts flowing abruptly with a very large viscosity decrease caused by the flow. This leads to avalanche behavior that accounts for the instability of quick clay soils. Reproducing landslides on a small scale in the laboratory shows that an additional factor that determines the violence of the slides is the inhomogeneity of the flow. We propose a simple yield stress model capable of reproducing the laboratory landslide data, allowing us to relate landslides to the measured rheology.

  11. Radiometric method and abnormal explanation of landslide survey

    International Nuclear Information System (INIS)

    Ye Shulin; Sun Zhanxue; Luo Liangsheng


    Radioactivity exploration mechanism of landslide is researched. Radioactive measure technical and its anomaly explanation models of application is introduced. Test verification result of landslide body geological form (boundary and landslide body thickness) in the district of Wanzhou 233 of Chongqing city ancients landslide and the Yunyang new county Zhaiba landslide shows, it can be used in determining the body boundary (reason) line, investigating the underground current direction and landslide body moving direction, explaining that calculation of weathered zone thickness of landslide body. It can also increase the geological effect of landslide exploration in adaption with geology and drilling

  12. A submarine landslide source for the devastating 1964 Chenega tsunami, southern Alaska (United States)

    Brothers, Daniel; Haeussler, Peter J.; Lee Liberty,; David Finlayson,; Geist, Eric L.; Labay, Keith A.; Michael Byerly,


    During the 1964 Great Alaska earthquake (Mw 9.2), several fjords, straits, and bays throughout southern Alaska experienced significant tsunami runup of localized, but unexplained origin. Dangerous Passage is a glacimarine fjord in western Prince William Sound, which experienced a tsunami that devastated the village of Chenega where 23 of 75 inhabitants were lost – the highest relative loss of any community during the earthquake. Previous studies suggested the source of the devastating tsunami was either from a local submarine landslide of unknown origin or from coseismic tectonic displacement. Here we present new observations from high-resolution multibeam bathymetry and seismic reflection surveys conducted in the waters adjacent to the village of Chenega. The seabed morphology and substrate architecture reveal a large submarine landslide complex in water depths of 120–360 m. Analysis of bathymetric change between 1957 and 2014 indicates the upper 20–50 m (∼0.7 km3) of glacimarine sediment was destabilized and evacuated from the steep face of a submerged moraine and an adjacent ∼21 km2 perched sedimentary basin. Once mobilized, landslide debris poured over the steep, 130 m-high face of a deeper moraine and then blanketed the terminal basin (∼465 m water depth) in 11 ± 5 m of sediment. These results, combined with inverse tsunami travel-time modeling, suggest that earthquake- triggered submarine landslides generated the tsunami that struck the village of Chenega roughly 4 min after shaking began. Unlike other tsunamigenic landslides observed in and around Prince William Sound in 1964, the failures in Dangerous Passage are not linked to an active submarine delta. The requisite environmental conditions needed to generate large submarine landslides in glacimarine fjords around the world may be more common than previously thought. 

  13. Assessment of submarine landslides hazard through geotechnical and rheological analysis of sediments on the French Atlantic continental slope (United States)

    Toucanne, S.; Howlett, S.; Garziglia, S.; Silva Jacinto, R.; Courgeon, S.; Sabine, M.; Riboulot, V.; Marsset, B.


    In the aftermath of the devastating tsunami on the Japanese coast in 2011, a French multi-partnership project called TANDEM has been launched to assess the impact of tsunamis generated or propagated in the vicinity of French Channel and Atlantic coastlines. Tsunami are usually generated by earthquakes, but can also be triggered by submarine landslides. This study focuses on submarine landslides along the French Atlantic continental slope using data that were mainly collected in August 2015 during the GITAN cruise (R/V Pourquoi Pas?). Following geomorphological, geophysical and sedimentological analysis of the Bay of Biscay, efforts were oriented towards the determination of the sediment properties controlling landslide dynamics from in situ and laboratory measurements. Preliminary results show over 700 landslide scars on the French Atlantic continental slope, with most of them occurring between 400 and 1000m water depth and in canyon environments. The Plio-Quaternary sediments draping the majority of the Bay of Biscay are generally normally consolidated and composed of high plasticity clays. They show similar geomechanical properties throughout the area studied, with linear evolutions with depth and good reproducibility for rheological parameters such as Storage and Loss modulus. These similarities allow to extend geotechnical and rheological models to a regional scale in the Bay of Biscay. Our multi-disciplinary approach will provide the tools to assess continental slope failures and submarine landslides generation. Finally, we will aim to qualify and quantify the volumes and flow properties of sediment transported obtained through slope-stability modeling on SAMU-3D and rheology modelling on Nixes-SPH. These results will provide the TANDEM actors with the information necessary to simulate tsunami wave generation.

  14. Modelling the landslide area and sediment discharge in landslide-dominated region, Taiwan (United States)

    Teng, Tse-Yang; Huang, -Chuan, Jr.; Lee, Tsung-Yu; Chen, Yi-Chin; Jan, Ming-Young; Liu, Cheng-Chien


    Many studies have indicated the magnified increase of rainfall intensification, landsliding and subsequent sediment discharge due to the global warming effect. However, a few works synthesized the "chain reaction" from rainfall, landsliding to sediment discharge at the same time because of the limited observations of landslide area and sediment discharge during episodes. Besides, the sediment transport strongly depends on the sediment supply and stream power which interact conditionally. In this study, our goal is to build a model that can simulate time-series landslide area and subsequent sediment discharge. The synthesized model would be applied onto Tsengwen Reservoir watershed in southern Taiwan, where lots of landslides occur every year. Unlike other studies, our landslide model considers not only rainfall effect but also previous landslide status, which may be applied to landslide-dominated regions and explains the irrelevant relationship between typhoon rainfall and landslide area. Furthermore, our sediment transport model considers the sediment budget which couples transport- and supply-limited of sediment. The result shows that the simulated time-series landslide area and the sediment transport agree with the observation and the R2 are 0.88 and 0.56, respectively. Reactivated ratio of previous landslide area is 72.7% which indicates the high reoccurrence of historical landslide in landslide-dominated regions. We divided nine historical typhoons into three periods to demonstrate the effect of sediment supply/supply-limited condition upon sediment transport. For instance, the rainfall is smaller in period 3 than in period 1 but the sediment transport is higher in period 3 due to the catastrophic landslide (typhoon Morakot) during period 2. We argue that quantifying sediment transport should couple not only with water discharge but sediment budget, which is rarely considered in calculating sediment transport. Moreover, the parameterization of the controlling

  15. Landsliding and its multiscale influence on mountainscapes

    NARCIS (Netherlands)

    Restrepo, C.; Walker, L.R.; Bussmann, R.; Claessens, L.


    Landsliding is a complex process that modifies mountainscapes worldwide. Its severe and sometimes long-lasting negative effects contrast with the less-documented positive effects on ecosystems, raising numerous questions about the dual role of landsliding, the feedbacks between biotic and geomorphic

  16. Landslide research in the South Wales coalfield

    International Nuclear Information System (INIS)

    Bentley, S.P.; Siddle, H.J.


    The areal density of landslides in the coalfield of South Wales is one of the highest in the UK. During the past 100 years landsliding has had considerable impact, causing structural damage and loss of life. Most of the landslides were initiated under periglacial conditions but many became reactivated due to the activities of man, particularly, during the late 19th century when widespread urban and industrial development commenced in the Welsh valleys. A number of the area's larger landslides are first-time slides which occurred during the past 100 years. This paper sets out to chart the history of landslide research in the coalfield, which began through work by mining engineers. 47 refs., 6 figs., 2 tabs

  17. Assessing Landslide Hazard Using Artificial Neural Network

    DEFF Research Database (Denmark)

    Farrokhzad, Farzad; Choobbasti, Asskar Janalizadeh; Barari, Amin


    failure" which is main concentration of the current research and "liquefaction failure". Shear failures along shear planes occur when the shear stress along the sliding surfaces exceed the effective shear strength. These slides have been referred to as landslide. An expert system based on artificial...... and factor of safety. It can be stated that the trained neural networks are capable of predicting the stability of slopes and safety factor of landslide hazard in study area with an acceptable level of confidence. Landslide hazard analysis and mapping can provide useful information for catastrophic loss...... reduction, and assist in the development of guidelines for sustainable land use planning. The analysis is used to identify the factors that are related to landslides and to predict the landslide hazard in the future based on such a relationship....

  18. Landslides risk mitigation along lifelines (United States)

    Capparelli, G.; Versace, P.; Artese, G.; Costanzo, S.; Corsonello, P.; Di Massa, G.; Mendicino, G.; Maletta, D.; Leone, S.; Muto, F.; Senatore, A.; Troncone, A.; Conte, E.; Galletta, D.


    The paper describes an integrated, innovative and efficient solution to manage risk issues associated to landslides interfering with infrastructures. The research project was submitted for financial support in the framework of the Multi -regional Operational Programme 2007-13: Research and Competitiveness funded by the Ministry of Research (MIUR) and co-funded by the European Regional Development Fund. The project is aimed to developing and demonstrating an integrated system of monitoring, early warning and mitigation of landslides risk. The final goal is to timely identify potentially dangerous landslides, and to activate all needed impact mitigation measures, including the information delivery. The essential components of the system include monitoring arrays, telecommunication networks and scenario simulation models, assisted by a data acquisition and processing centre, and a traffic control centres. Upon integration, the system will be experimentally validated and demonstrated over ca. 200 km of three highway sections, crossing the regions of Campania, Basilicata, Calabria and Sicily. Progress in the state of art is represented by the developments in the field of environmental monitoring and in the mathematical modeling of landslides and by the development of services for traffic management. The approach to the problem corresponds to a "systemic logics" where each developed component foresees different interchangeable technological solutions to maximize the operational flexibility. The final system may be configured as a simple to complex structure, including different configurations to deal with different scenarios. Specifically, six different monitoring systems will be realized: three "point" systems, made up of a network of locally measuring sensors, and three "area" systems to remotely measure the displacements of large areas. Each network will be fully integrated and connected to a unique data transmission system. Standardized and shared procedures for the

  19. Constraining relationships between rainfall and landsliding with satellite derived rainfall measurements and landslide inventories. (United States)

    Marc, Odin; Malet, Jean-Philippe; Stumpf, Andre; Gosset, Marielle


    In mountainous and hilly regions, landslides are an important source of damage and fatalities. Landsliding correlates with extreme rainfall events and may increase with climate change. Still, how precipitation drives landsliding at regional scales is poorly understood quantitatively in part because constraining simultaneously landsliding and rainfall across large areas is challenging. By combining optical images acquired from satellite observation platforms and rainfall measurements from satellite constellations we are building a database of landslide events caused by with single storm events. We present results from storm-induced landslides from Brazil, Taiwan, Micronesia, Central America, Europe and the USA. We present scaling laws between rainfall metrics derived by satellites (total rainfall, mean intensity, antecedent rainfall, ...) and statistical descriptors of landslide events (total area and volume, size distribution, mean runout, ...). Total rainfall seems to be the most important parameter driving non-linearly the increase in total landslide number, and area and volume. The maximum size of bedrock landslides correlates with the total number of landslides, and thus with total rainfall, within the limits of available topographic relief. In contrast, the power-law scaling exponent of the size distribution, controlling the relative abundance of small and large landslides, appears rather independent of the rainfall metrics (intensity, duration and total rainfall). These scaling laws seem to explain both the intra-storm pattern of landsliding, at the scale of satellite rainfall measurements ( 25kmx25km), and the different impacts observed for various storms. Where possible, we evaluate the limits of standard rainfall products (TRMM, GPM, GSMaP) by comparing them to in-situ data. Then we discuss how slope distribution and other geomorphic factors (lithology, soil presence,...) modulate these scaling laws. Such scaling laws at the basin scale and based only on a

  20. Application of remote sensing data and GIS for landslide risk assessment as an environmental threat to Izmir city (west Turkey). (United States)

    Akgun, Aykut; Kıncal, Cem; Pradhan, Biswajeet


    In this study, landslide risk assessment for Izmir city (west Turkey) was carried out, and the environmental effects of landslides on further urban development were evaluated using geographical information systems and remote sensing techniques. For this purpose, two different data groups, namely conditioning and triggering data, were produced. With the help of conditioning data such as lithology, slope gradient, slope aspect, distance from roads, distance from faults and distance from drainage lines, a landslide susceptibility model was constructed by using logistic regression modelling approach. The accuracy assessment of the susceptibility map was carried out by the area under curvature (AUC) approach, and a 0.810 AUC value was obtained. This value shows that the map obtained is successful. Due to the fact that the study area is located in an active seismic region, earthquake data were considered as primary triggering factor contributing to landslide occurrence. In addition to this, precipitation data were also taken into account as a secondary triggering factor. Considering the susceptibility data and triggering factors, a landslide hazard index was obtained. Furthermore, using the Aster data, a land-cover map was produced with an overall kappa value of 0.94. From this map, settlement areas were extracted, and these extracted data were assessed as elements at risk in the study area. Next, a vulnerability index was created by using these data. Finally, the hazard index and the vulnerability index were combined, and a landslide risk map for Izmir city was obtained. Based on this final risk map, it was observed that especially south and north parts of the Izmir Bay, where urbanization is dense, are threatened to future landsliding. This result can be used for preliminary land use planning by local governmental authorities.

  1. Variability in soil-water retention properties and implications for physics-based simulation of landslide early warning criteria (United States)

    Thomas, Matthew A.; Mirus, Benjamin B.; Collins, Brian D.; Lu, Ning; Godt, Jonathan W.


    Rainfall-induced shallow landsliding is a persistent hazard to human life and property. Despite the observed connection between infiltration through the unsaturated zone and shallow landslide initiation, there is considerable uncertainty in how estimates of unsaturated soil-water retention properties affect slope stability assessment. This source of uncertainty is critical to evaluating the utility of physics-based hydrologic modeling as a tool for landslide early warning. We employ a numerical model of variably saturated groundwater flow parameterized with an ensemble of texture-, laboratory-, and field-based estimates of soil-water retention properties for an extensively monitored landslide-prone site in the San Francisco Bay Area, CA, USA. Simulations of soil-water content, pore-water pressure, and the resultant factor of safety show considerable variability across and within these different parameter estimation techniques. In particular, we demonstrate that with the same permeability structure imposed across all simulations, the variability in soil-water retention properties strongly influences predictions of positive pore-water pressure coincident with widespread shallow landsliding. We also find that the ensemble of soil-water retention properties imposes an order-of-magnitude and nearly two-fold variability in seasonal and event-scale landslide susceptibility, respectively. Despite the reduced factor of safety uncertainty during wet conditions, parameters that control the dry end of the soil-water retention function markedly impact the ability of a hydrologic model to capture soil-water content dynamics observed in the field. These results suggest that variability in soil-water retention properties should be considered for objective physics-based simulation of landslide early warning criteria.

  2. Landslides in the area of the Jastrzebie town protective pillar

    Energy Technology Data Exchange (ETDEWEB)

    Rybicki, S


    Analyzes 76 landslides in the area of the safety pillar of Jastrzebie in the Rybnik coal region. Of 76 landslides 60% fell on natural slopes with an angle of 25-50 degrees, 22% on natural slopes with a 5-25 degree angle, 10% on man-made cuts and 8% on embankments. About 78% of the landslides was associated with water bearing layers. Of the 76 landslides 32 were situated in the safety pillar and 44 close to the pillar. Thirty-three landslides were closely associated with underground mining: 30 landslides were caused by longwall mining (landslide position was related to working face position), a further 3 were associated with mining in general. Statistical data on landslides associated with underground coal mining are analyzed: landslide area, angle of slope inclination, height, landslide range, water conditions, types of soils, types of mining areas classified according to effects of mining damage. 8 refs.

  3. Mechanical-mathematical modeling for landslide process (United States)

    Svalova, V.


    Landslides process is one of the most widespread and dangerous processes in the urbanized territories. In Moscow the landslips occupy about 3 % of the most valuable territory of city. There are near 20 places of deep landslides and some hundreds of shallow landslides in Moscow. In Russia many towns are located near rivers on high coastal sides. There are many churches and historical buildings on high costs of Volga River and Moscow River. The organization of monitoring is necessary for maintenance of normal functioning of city infrastructure in a coastal zone and duly realization of effective protective actions. Last years the landslide process activization took place in Moscow. The right coast of river Moscow on its significant extent within the limits of city Moscow is struck by deep block landslides with depth up to 90 - 100 m which formation occurred in preglacial time with basis of sliding in Callovian-Oxford clays of Jurassic system on 25 - 30 m below modern level of the river . One of landslide sites is on Vorob'evy mountains, on a high slope of the right coast of the river Moscow with height of 65 m. There is a historical monument - «Andreevsky monastery», based in 1648. Also there are the complex of buildings of Presidium of the Russian Academy of Sciences, constructed in 70 - 80th years of 20-th century, bridge with station of underground "Vorob'evy mountain", constructions of sport complexes. Landslide slope is in active condition, and there are many attributes of activization of deep block landslide. In June 2007 a rather big landslide took place there near ski-jump. Another landslide site is in a southeast part of Moscow, occupying the right coast of river Moscow near museum - reserve "Kolomenskoye". The slope in this place has height of 38 - 40 m. Motions of deep landslips have begun from 1960 in connection with construction of collectors. In 70th years of XX century there was a strong activization of a slope with formation of cracks by extent up to

  4. Accuracy assessment of landslide prediction models

    International Nuclear Information System (INIS)

    Othman, A N; Mohd, W M N W; Noraini, S


    The increasing population and expansion of settlements over hilly areas has greatly increased the impact of natural disasters such as landslide. Therefore, it is important to developed models which could accurately predict landslide hazard zones. Over the years, various techniques and models have been developed to predict landslide hazard zones. The aim of this paper is to access the accuracy of landslide prediction models developed by the authors. The methodology involved the selection of study area, data acquisition, data processing and model development and also data analysis. The development of these models are based on nine different landslide inducing parameters i.e. slope, land use, lithology, soil properties, geomorphology, flow accumulation, aspect, proximity to river and proximity to road. Rank sum, rating, pairwise comparison and AHP techniques are used to determine the weights for each of the parameters used. Four (4) different models which consider different parameter combinations are developed by the authors. Results obtained are compared to landslide history and accuracies for Model 1, Model 2, Model 3 and Model 4 are 66.7, 66.7%, 60% and 22.9% respectively. From the results, rank sum, rating and pairwise comparison can be useful techniques to predict landslide hazard zones

  5. TRIGRS Application for landslide susceptibility mapping (United States)

    Sugiarti, K.; Sukristiyanti, S.


    Research on landslide susceptibility has been carried out using several different methods. TRIGRS is a modeling program for landslide susceptibility by considering pore water pressure changes due to infiltration of rainfall. This paper aims to present a current state-of-the-art science on the development and application of TRIGRS. Some limitations of TRIGRS, some developments of it to improve its modeling capability, and some examples of the applications of some versions of it to model the effect of rainfall variation on landslide susceptibility are reviewed and discussed.

  6. Environmental baseline survey report for West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge and parcel 21D in the vicinity of the East Technology Park, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    King, David A. [Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program


    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy?s (DOE?s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only no-further-investigation (NFI) reports. Groundwater sampling was also conducted to support a Parcel 21d decision. Based on available data West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, and West Pine Ridge are not impacted by site operations and are not subject to actions per the Federal Facility Agreement (FFA). This determination is supported by visual inspections, records searches and interviews, groundwater conceptual modeling, approved NFI reports, analytical data, and risk analysis results. Parcel 21d data, however, demonstrate impacts from site

  7. Environmental baseline survey report for West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge and parcel 21D in the vicinity of the East Technology Park, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    King, David A.


    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy's (DOE's) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only no-further-investigation (NFI) reports. Groundwater sampling was also conducted to support a Parcel 21d decision. Based on available data West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, and West Pine Ridge are not impacted by site operations and are not subject to actions per the Federal Facility Agreement (FFA). This determination is supported by visual inspections, records searches and interviews, groundwater conceptual modeling, approved NFI reports, analytical data, and risk analysis results. Parcel 21d data, however, demonstrate impacts from site

  8. Fostering the uptake of satellite Earth Observation data for landslide hazard understanding: the CEOS Landslide Pilot (United States)

    Kirschbaum, Dalia; Malet, Jean-Philippe; Roessner, Sigrid


    Landslides occur around the world, on every continent, and play an important role in the evolution of landscapes. They also represent a serious hazard in many areas of the world. Despite their importance, it has been estimated that past landslide and landslide potential maps cover less than 1% of the slopes in these landmasses. Systematic information on the type, abundance, and distribution of existing landslides is lacking. Even in countries where landslide information is abundant (e.g. Italy), the vast majority of landslides caused by meteorological (intense or prolonged rainfall, rapid snowmelt) or geophysical (earthquake) triggers go undetected. This paucity of knowledge has consequences on the design of effective remedial and mitigation measures. Systematic use of Earth observation (EO) data and technologies can contribute effectively to detect, map, and monitor landslides, and landslide prone hillsides, in different physiographic and climatic regions. The CEOS (Committee on Earth Observation Satellites) Working Group on Disasters has recently launched a Landslide Pilot (period 2017-2019) with the aim to demonstrate the effective exploitation of satellite EO across the full cycle of landslide disaster risk management, including preparedness, response, and recovery at global, regional, and local scales, with a distinct multi-hazard focus on cascading impacts and risks. The Landslide Pilot is focusing efforts on three objectives: 1. Establish effective practices for merging different Earth Observation data (e.g. optical and radar) to better monitor and map landslide activity over time and space. 2. Demonstrate how landslide products, models, and services can support disaster risk management for multi-hazard and cascading landslide events. 3. Engage and partner with data brokers and end users to understand requirements and user expectations and get feedback through the activities described in objectives 1-2. The Landslide Pilot was endorsed in April 2016 and work

  9. An analysis of on time evolution of landslide (United States)

    Tsai, Chienwei; Lien, Huipang


    In recent years, the extreme hydrological phenomenon in Taiwan is obvious. Because the increase of heavy rainfall frequency has resulted in severe landslide disaster, the watershed management is very important and how to make the most effective governance within the limited funds is the key point. In recent years many scholars to develop empirical models said that virtually rainfall factors exist and as long as rainfall conditions are met the minimum requirements of the model, landslide will occur. However, rainfall is one of the elements to the landslide, but not the only one element. Rainfall, geology and earthquake all contributed to the landslide as well. Preliminary research found that many landslides occur at the same location constantly and after repeating landslide, the slope had the characteristic of landslide immunity over time, even if the rainfall exceeded the standard, the landslide could not be triggered in the near term. This study investigated the surface conditions of slope that occur repeated landslide. It is difficult to be the basis of subsequent anti-disaster if making rainfall is the only condition to contribute to the landslide. This study analyzes 50 landslides in 2004 2013. Repeated landslide is defined as existed landslide in satellite images of reference period which it's bare area is shrinking or disappearing gradually but the restoration occur landslide again in some period time. The statistical analysis of the study found that 96% of landslide has repeated landslide and on average repeated landslide occurs 3.4 years in 10 years by one year as the unit. The highest of repeated landslide happened in 2010. It would presume that Typhoon Morakot in 2010 brought torrential rain which suffered southern mountain areas severely so the areas occurred repeated landslide.

  10. Landslide: Mineralogical and Physical Investigation (United States)

    Tudor, Viluș; Grozav, Adia; Rogobete, Gheorghe


    In order to construct a road bed foundation, if land has moved, on an area with old landslides, there is a high chance of it moving again. The investigation was made in a region with hilly relief, in which the parent materials of soils are argillaceous marls of Pliocene age. Because the slope is scarped and the versant has been cut, the soil mass slide favoured of the particle-size distribution dominated by heavy clay. With a reiteratedly percolative moisture regime, the soil material is saturated in water fora long period (700-800 mm precipitation/year), and that can increase the slope mass, thereby increasing the driving forces. In a soil profile situated on the top of the hill, with landslide for about 40 m length of the road, disturbed and undisturbed soil samples were analysed physic-chemical and mineralogical. For the heavy and light minerals from the sand fraction a polarized light analyser is used, and for clay minerals X-ray, differential thermal and infrared absorption method are used. The particle-size distribution in the soil profile is dominated by the clay fraction, which reached 53.2% in the ABt horizon and 63.0% in the Bt horizon (67-93 cm depth). The structure of the light minerals, consists of quartz (41-58%); feldspar (10.16-18.10%); muscovite (14.10-26.04). The heavy minerals are oxides (2.61-15.26%), hornblende (0.58-2.87%) and biotite (0.51-2.68%). It must be mentioned the presence of the metamorphic minerals, with the source of the Poiana Rusca mountains. These minerals are epidote (1.01-1.86%), disthene (0.70-1.86%), staurolite (0.73-2.46%) and sillimanite (0.35-0.45%). The clay minerals, inherited from the parent material or formed during the soil-forming process are dominated by smectite, which represent (71-85%) from the total clay minerals, illite 10-21%, and Kaolinite, 4-12%. Rheological properties, like plastic index (53.8%), activity index (1.01%) and consistency index (0.99-1.00%) show that the shrinkage - swelling processes are

  11. Landslide inventory and susceptibility modelling using geospatial tools, in Hunza-Nagar valley, northern Pakistan

    NARCIS (Netherlands)

    Bacha, Alam Sher; Shafique, Muhammad; van der Werff, H.M.A.


    A comprehensive landslide inventory and susceptibility maps are prerequisite for developing and implementing landslide mitigation strategies. Landslide susceptibility maps for the landslides prone regions in northern Pakistan are rarely available. The Hunza-Nagar valley in northern Pakistan is known

  12. Great landslide events in Italian artificial reservoirs

    Directory of Open Access Journals (Sweden)

    A. Panizzo


    Full Text Available The empirical formulations to forecast landslide generated water waves, recently defined in the framework of a research program funded by the Italian National Dam Office RID (Registro Italiano Dighe, are here used to study three real cases of subaerial landslides which fell down italian artificial reservoirs. It is well known that impulse water waves generated by landslides constitute a very dangerous menace for human communities living in the shoreline of the artificial basin or downstream the dam. In 1963, the menace became tragedy, when a 270 millions m3 landslide fell down the Vajont reservoir (Italy, generated an impulse wave which destroyed the city of Longarone, and killed 2000 people. The paper is aimed at presenting the very satisfactorily reproduction of the events at hand by using forecasting formulations.  

  13. Great landslide events in Italian artificial reservoirs (United States)

    Panizzo, A.; de Girolamo, P.; di Risio, M.; Maistri, A.; Petaccia, A.


    The empirical formulations to forecast landslide generated water waves, recently defined in the framework of a research program funded by the Italian National Dam Office RID (Registro Italiano Dighe), are here used to study three real cases of subaerial landslides which fell down italian artificial reservoirs. It is well known that impulse water waves generated by landslides constitute a very dangerous menace for human communities living in the shoreline of the artificial basin or downstream the dam. In 1963, the menace became tragedy, when a 270 millions m3 landslide fell down the Vajont reservoir (Italy), generated an impulse wave which destroyed the city of Longarone, and killed 2000 people. The paper is aimed at presenting the very satisfactorily reproduction of the events at hand by using forecasting formulations.

  14. Development of geoportal for landslide monitoring

    Directory of Open Access Journals (Sweden)

    Sladić Dubravka


    Full Text Available The paper presents the implementation of geoportal for landslide monitoring which which includes two subsystems: a system for acquisition, storage and distribution of data on landslides and real time alert system. System for acquisition, storage and distribution of data on landslides include raster and vector spatial data on landslides affected areas, as well as metadata. Alert system in real time is associated with a sensor for detecting displacement, which performs constant measurements and signals in case of exceeding the reference value. The system was developed in accordance with the standards in the field of GIS: ISO 19100 series of standards and OpenGIS Consortium and is based on service-oriented architecture and principles of spatial data infrastructures. [Projekat Ministarstva nauke Republike Srbije, br. TR37017: Modeliranje stanja i strukture padinskih procesa primenom GNSS i tehnologija skeniranja laserom i georadarom

  15. Landslide hazard assessment in the Collazzone area, Umbria, Central Italy

    Directory of Open Access Journals (Sweden)

    F. Guzzetti


    Full Text Available We present the results of the application of a recently proposed model to determine landslide hazard. The model predicts where landslides will occur, how frequently they will occur, and how large they will be in a given area. For the Collazzone area, in the central Italian Apennines, we prepared a multi-temporal inventory map through the interpretation of multiple sets of aerial photographs taken between 1941 and 1997 and field surveys conducted in the period between 1998 and 2004. We then partitioned the 79 square kilometres study area into 894 slope units, and obtained the probability of spatial occurrence of landslides by discriminant analysis of thematic variables, including morphology, lithology, structure and land use. For each slope unit, we computed the expected landslide recurrence by dividing the total number of landslide events inventoried in the terrain unit by the time span of the investigated period. Assuming landslide recurrence was constant, and adopting a Poisson probability model, we determined the exceedance probability of having one or more landslides in each slope unit, for different periods. We obtained the probability of landslide size, a proxy for landslide magnitude, by analysing the frequency-area statistics of landslides, obtained from the multi-temporal inventory map. Lastly, assuming independence, we determined landslide hazard for each slope unit as the joint probability of landslide size, of landslide temporal occurrence, and of landslide spatial occurrence.

  16. An illustrated landslide handbook for developing nations (United States)

    Highland, Lynn M.; Bobrowsky, Peter


    As landslides continue to be a hazard that account for large numbers of human and animal casualties, property loss, and infrastructure damage, as well as impacts on the natural environment, it is incumbent on developed nations that resources be allocated to educate affected populations in less developed nations, and provide them with tools to effectively manage this hazard. Given that the engineering, planning and zoning, and mitigation techniques for landslide hazard reduction are more accessible to developed nations, it is crucial that such landslide hazard management tools be communicated to less developed nations in a language that is not overly technical, and provides information on basic scientific explanations on where, why and how landslides occur. The experiences of the United States, Canada, and many other nations demonstrate that, landslide science education, and techniques for reducing damaging landslide impacts may be presented in a manner that can be understood by the layperson. There are various methods through which this may be accomplished–community-level education, technology transfer, and active one-on-one outreach to national and local governments, and non-governmental organizations (NGOs), who disseminate information throughout the general population. The population at large can also benefit from the dissemination of landslide information directly to individual community members. The United States Geological Survey and the Geological Survey of Canada have just published and will distribute a universal landslide handbook that can be easily made available to emergency managers, local governments, and individuals. The handbook, “The Landslide Handbook: A Guide to Understanding Landslides” is initially published as U.S. Geological Survey Circular 1325, in English, available in print, and accessible on the internet. It is liberally illustrated with schematics and photographs, and provides the means for a basic understanding of landslides, with

  17. Landslide susceptibility map: from research to application (United States)

    Fiorucci, Federica; Reichenbach, Paola; Ardizzone, Francesca; Rossi, Mauro; Felicioni, Giulia; Antonini, Guendalina


    Susceptibility map is an important and essential tool in environmental planning, to evaluate landslide hazard and risk and for a correct and responsible management of the territory. Landslide susceptibility is the likelihood of a landslide occurring in an area on the basis of local terrain conditions. Can be expressed as the probability that any given region will be affected by landslides, i.e. an estimate of "where" landslides are likely to occur. In this work we present two examples of landslide susceptibility map prepared for the Umbria Region and for the Perugia Municipality. These two maps were realized following official request from the Regional and Municipal government to the Research Institute for the Hydrogeological Protection (CNR-IRPI). The susceptibility map prepared for the Umbria Region represents the development of previous agreements focused to prepare: i) a landslide inventory map that was included in the Urban Territorial Planning (PUT) and ii) a series of maps for the Regional Plan for Multi-risk Prevention. The activities carried out for the Umbria Region were focused to define and apply methods and techniques for landslide susceptibility zonation. Susceptibility maps were prepared exploiting a multivariate statistical model (linear discriminant analysis) for the five Civil Protection Alert Zones defined in the regional territory. The five resulting maps were tested and validated using the spatial distribution of recent landslide events that occurred in the region. The susceptibility map for the Perugia Municipality was prepared to be integrated as one of the cartographic product in the Municipal development plan (PRG - Piano Regolatore Generale) as required by the existing legislation. At strategic level, one of the main objectives of the PRG, is to establish a framework of knowledge and legal aspects for the management of geo-hydrological risk. At national level most of the susceptibility maps prepared for the PRG, were and still are obtained

  18. Morphology and internal structure of a dormant landslide in a hilly area: The Collinabos landslide (Belgium ) (United States)

    Van Den Eeckhaut, M.; Verstraeten, G.; Poesen, J.


    This study attempts to reconstruct the history of the Collinabos landslide, a landslide with a fresh morphology that is representative for more than 150 dormant, deep-seated (> 3 m) landslides in the Flemish Ardennes (Belgium). A geomorphological map was created based on LIDAR (Light Detection and Ranging)-derived maps and detailed field surveys. The map showed that the landslide consisted of three zones with significant differences in surface topography. The northern landslide zone 1 is characterised by at least five reverse slopes, whereas zones 2 and 3, the southern landslide zones, have only two reverse slopes and a convex foot. Electric resistivity profiles measured in zones 1 and 2 revealed that the differences in surface topography were not related to differences in internal structure as both parts of the landslide were initiated as a rotational earth slide with a surface of rupture at 15 m deep, where the displaced material broke apart in two blocks. However, two shear surfaces of reactivations within landslide debris were only distinguished in the accumulation area of zone 1. The observed differences in surface morphology can be caused by a temporary conversion of a forest into cropland in zone 2. It is suggested that reverse slopes of smaller reactivations within landslide debris were obliterated during the agricultural activities. AMS radiocarbon dating of organic material found in ponds located in reverse slopes generally resulted in relatively recent dates (i.e. 1400-1950 Cal AD) suggesting that several of the small local reactivations occurred in that period. One dating at 8700-8440 Cal BP of organic matter collected in a reverse slope in zone 1 suggests that an initiation under periglacial conditions cannot be excluded for the Collinabos landslide. By combining different technologies, this study provides valuable information for a better understanding of dormant landslides.

  19. Earthquake-triggered landslides in southwest China


    X. L. Chen; Q. Zhou; H. Ran; R. Dong


    Southwest China is located in the southeastern margin of the Tibetan Plateau and it is a region of high seismic activity. Historically, strong earthquakes that occurred here usually generated lots of landslides and brought destructive damages. This paper introduces several earthquake-triggered landslide events in this region and describes their characteristics. Also, the historical data of earthquakes with a magnitude of 7.0 or greater, having occurred in this region, is col...

  20. Modeling tsunamis induced by retrogressive submarine landslides (United States)

    Løvholt, F.; Kim, J.; Harbitz, C. B.


    Enormous submarine landslides having volumes up to thousands of km3 and long run-out may cause tsunamis with widespread effects. Clay-rich landslides, such as Trænadjupet and Storegga offshore Norway commonly involve retrogressive mass and momentum release mechanisms that affect the tsunami generation. Therefore, such landslides may involve a large amount of smaller blocks. As a consequence, the failure mechanisms and release rate of the individual blocks are of importance for the tsunami generation. Previous attempts to model the tsunami generation due to retrogressive landslides are few, and limited to idealized conditions. Here, we review the basic effects of retrogression on tsunamigenesis in simple geometries. To this end, two different methods are employed for the landslide motion, a series block with pre-scribed time lags and kinematics, and a dynamic retrogressive model where the inter-block time lag is determined by the model. The effect of parameters such as time lag on wave-height, wave-length, and dispersion are discussed. Finally, we discuss how the retrogressive effects may have influenced the tsunamis due to large landslides such as the Storegga slide. The research leading to these results has received funding from the Research Council of Norway under grant number 231252 (Project TsunamiLand) and the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 603839 (Project ASTARTE).

  1. A multi-annual landslide inventory for the assessment of shallow landslide susceptibility - Two test cases in Vorarlberg, Austria (United States)

    Zieher, Thomas; Perzl, Frank; Rössel, Monika; Rutzinger, Martin; Meißl, Gertraud; Markart, Gerhard; Geitner, Clemens


    Geomorphological landslide inventories provide crucial input data for any study on the assessment of landslide susceptibility, hazard or risk. Several approaches for assessing landslide susceptibility have been proposed to identify areas particularly vulnerable to this natural hazard. What they have in common is the need for data of observed landslides. Therefore the first step of any study on landslide susceptibility is usually the compilation of a geomorphological landslide inventory using a geographical information system. Recent research has proved the feasibility of orthophoto interpretation for the preparation of an inventory aimed at the delineation of landslides with the use of distinctive signs in the imagery data. In this study a multi-annual landslide inventory focusing on shallow landslides (i.e. translational soil slides of 0-2 m in depth) was compiled for two study areas in Vorarlberg (Austria) from the interpretation of nine orthophoto series. In addition, derivatives of two generations of airborne laser scanning data aided the mapping procedure. Landslide scar areas were delineated on the basis of a high-resolution differential digital terrain model. The derivation of landslide volumes, depths and depth-to-length ratios are discussed. Results show that most mapped landslides meet the definition of a shallow landslide. The inventory therefore provides the data basis for the assessment of shallow landslide susceptibility and allows for the application of various modelling techniques.

  2. Landslides and engineering geology of the Seattle, Washington, area (United States)

    Baum, Rex L.; Godt, Jonathan W.; Highland, Lynn M.


    This volume brings together case studies and summary papers describing the application of state-of-the-art engineering geologic methods to landslide hazard analysis for the Seattle, Washington, area. An introductory chapter provides a thorough description of the Quaternary and bedrock geology of Seattle. Nine additional chapters review the history of landslide mapping in Seattle, present case studies of individual landslides, describe the results of spatial assessments of landslide hazard, discuss hydrologic controls on landsliding, and outline an early warning system for rainfall-induced landslides.

  3. Landslide temporal analysis and susceptibility assessment as bases for landslide mitigation, Machu Picchu, Peru

    Czech Academy of Sciences Publication Activity Database

    Klimeš, Jan


    Roč. 70, č. 2 (2013), s. 913-925 ISSN 1866-6280 Institutional research plan: CEZ:AV0Z30460519 Keywords : landslide inventory * landslide frequency * susceptibility map Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 1.572, year: 2013

  4. Landslide mobility and hazards: implications of the 2014 Oso disaster (United States)

    Iverson, Richard M.; George, David L.; Allstadt, Kate E.; Reid, Mark E.; Collins, Brian D.; Vallance, James W.; Schilling, Steve P.; Godt, Jonathan W.; Cannon, Charles; Magirl, Christopher S.; Baum, Rex L.; Coe, Jeffrey A.; Schulz, William; Bower, J. Brent


    Landslides reflect landscape instability that evolves over meteorological and geological timescales, and they also pose threats to people, property, and the environment. The severity of these threats depends largely on landslide speed and travel distance, which are collectively described as landslide “mobility”. To investigate causes and effects of mobility, we focus on a disastrous landslide that occurred on 22 March 2014 near Oso, Washington, USA, following a long period of abnormally wet weather. The landslide's impacts were severe because its mobility exceeded that of prior historical landslides at the site, and also exceeded that of comparable landslides elsewhere. The ∼8×106 m3 landslide originated on a gently sloping (landslide began after about 50 s of preliminary slope movement, and observational evidence supports the hypothesis that the high mobility of the landslide resulted from liquefaction of water-saturated sediment at its base. Numerical simulation of the event using a newly developed model indicates that liquefaction and high mobility can be attributed to compression- and/or shear-induced sediment contraction that was strongly dependent on initial conditions. An alternative numerical simulation indicates that the landslide would have been far less mobile if its initial porosity and water content had been only slightly lower. Sensitive dependence of landslide mobility on initial conditions has broad implications for assessment of landslide hazards.

  5. Monsoon Rainfall and Landslides in Nepal (United States)

    Dahal, R. K.; Hasegawa, S.; Bhandary, N. P.; Yatabe, R.


    A large number of human settlements on the Nepal Himalayas are situated either on old landslide mass or on landslide-prone areas. As a result, a great number of people are affected by large- and small-scale landslides all over the Himalayas especially during monsoon periods. In Nepal, only in the half monsoon period (June 10 to August 15), 70, 50 and 68 people were killed from landslides in 2007, 2008 and 2009, respectively. In this context, this paper highlights monsoon rainfall and their implications in the Nepal Himalaya. In Nepal, monsoon is major source of rainfall in summer and approximately 80% of the annual total rainfall occurs from June to September. The measured values of mean annual precipitation in Nepal range from a low of approximately 250 mm at area north of the Himalaya to many areas exceeding 6,000 mm. The mean annual rainfall varying between 1500 mm and 2500 mm predominate over most of the country. In Nepal, the daily distribution of precipitation during rainy season is also uneven. Sometime 10% of the total annual precipitation can occur in a single day. Similarly, 50% total annual rainfall also can occur within 10 days of monsoon. This type of uneven distribution plays an important role in triggering many landslides in Nepal. When spatial distribution of landslides was evaluated from record of more than 650 landslides, it is found that more landslides events were concentrated at central Nepal in the area of high mean annual rainfall. When monsoon rainfall and landslide relationship was taken into consideration, it was noticed that a considerable number of landslides were triggered in the Himalaya by continuous rainfall of 3 to 90 days. It has been noticed that continuous rainfall of few days (5 days or 7 days or 10 days) are usually responsible for landsliding in the Nepal Himalaya. Monsoon rains usually fall with interruptions of 2-3 days and are generally characterized by low intensity and long duration. Thus, there is a strong role of

  6. Urban Greening Bay Area (United States)

    Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

  7. Modeling landslide recurrence in Seattle, Washington, USA (United States)

    Salciarini, Diana; Godt, Jonathan W.; Savage, William Z.; Baum, Rex L.; Conversini, Pietro


    To manage the hazard associated with shallow landslides, decision makers need an understanding of where and when landslides may occur. A variety of approaches have been used to estimate the hazard from shallow, rainfall-triggered landslides, such as empirical rainfall threshold methods or probabilistic methods based on historical records. The wide availability of Geographic Information Systems (GIS) and digital topographic data has led to the development of analytic methods for landslide hazard estimation that couple steady-state hydrological models with slope stability calculations. Because these methods typically neglect the transient effects of infiltration on slope stability, results cannot be linked with historical or forecasted rainfall sequences. Estimates of the frequency of conditions likely to cause landslides are critical for quantitative risk and hazard assessments. We present results to demonstrate how a transient infiltration model coupled with an infinite slope stability calculation may be used to assess shallow landslide frequency in the City of Seattle, Washington, USA. A module called CRF (Critical RainFall) for estimating deterministic rainfall thresholds has been integrated in the TRIGRS (Transient Rainfall Infiltration and Grid-based Slope-Stability) model that combines a transient, one-dimensional analytic solution for pore-pressure response to rainfall infiltration with an infinite slope stability calculation. Input data for the extended model include topographic slope, colluvial thickness, initial water-table depth, material properties, and rainfall durations. This approach is combined with a statistical treatment of rainfall using a GEV (General Extreme Value) probabilistic distribution to produce maps showing the shallow landslide recurrence induced, on a spatially distributed basis, as a function of rainfall duration and hillslope characteristics.

  8. Costs and deaths of landslides in Europe (United States)

    Haque, Ubydul; Blum, Philipp


    Landslides cause human and large economic losses worldwide and also in Europe. However, the quantification of associated costs and deaths is highly underestimated and still incomplete, thus the estimation of landslide costs and risk is still rather ambitious. Hence, in this study a spatio-temporal analysis of fatal landslides is presented for 27 European countries from 1995-2014. These landslides are mainly concentrated in mountainous areas. A total of 1370 fatalities are reported resulting from 476 landslides. The highest fatalities with 335 are observed in Turkey. In general, an increasing trend of fatal landslides is recognized starting in 2008. The latter is almost certainly triggered by an increase in natural extreme events such as storms (i.e. heavy rainfall) and floods. The highest annual economic loss is observed in Italy with 3.9 billion Euro per year. In contrast, in Germany the annual total loss is only about 0.3 billion Euro. The results of this study serves as an initial baseline information for further risk studies integrating landslide locations, local land use data, cost data, and will therefore certainly support the studied countries to better protect their citizens and assets. Acknowledgements We would like to acknowledge the valuable contributions by Paula F. da Silva, Peter Andersen, Jürgen Pilz, Ali Ardalan, Sergey R. Chalov, Jean-Philippe Malet, Mateja Jemec Auflič, Norina Andres, Eleftheria Poyiadji, Pedro C. Lamas, Wenyi Zhang, Igor Pesevski, Halldór G. Pétursson, Tayfun Kurt, Nikolai Dobrev, Juan Carlos García Davalillo, Matina Halkia, Stefano Ferri, George Gaprindashvili, Johanna Engström and David Keellings.

  9. Determining rainfall thresholds that trigger landslides in Colombia

    International Nuclear Information System (INIS)

    Mayorga Marquez, Ruth


    Considering that rainfall is the natural event that more often triggers landslides, it is important to study the relationship between this phenomenon and the occurrence of earth mass movements, by determining rainfall thresholds that trigger landslides in different zones of Colombia. The research presents a methodology that allows proposing rainfall thresholds that trigger landslides in Colombia, by means of a relationship between the accumulated rain in the soil (antecedent rainfall) and the rain that falls the day of the landslide occurrence (event rainfall)

  10. Geomorphological mapping of shallow landslides using UAVs (United States)

    Fiorucci, Federica; Giordan, Daniele; Dutto, Furio; Rossi, Mauro; Guzzetti, Fausto


    The mapping of event shallow landslides is a critical activity, due to the large number of phenomena, mostly with small dimension, affecting extensive areas. This is commonly done through aerial photo-interpretation or through field surveys. Nowadays, landslide maps can be realized exploiting other methods/technologies: (i) airborne LiDARs, (ii) stereoscopic satellite images, and (iii) unmanned aerial vehicles (UAVs). In addition to the landslide maps, these methods/technologies allow the generation of updated Digital Terrain Models (DTM). In December 2013, in the Collazzone area (Umbria, Central Italy), an intense rainfall event triggered a large number of shallow landslides. To map the landslides occurred in the area, we exploited data and images obtained through (A) an airborne LiDAR survey, (B) a remote controlled optocopter (equipped with a Canon EOS M) survey, and (C) a stereoscopic satellite WorldView II MS. To evaluate the mapping accuracy of these methods, we select two landslides and we mapped them using a GPS RTK instrumentation. We consider the GPS survey as the benchmark being the most accurate system. The results of the comparison allow to highlight pros and cons of the methods/technologies used. LiDAR can be considered the most accurate system and in addition it allows the extraction and the classification of the digital surface models from the surveyed point cloud. Conversely, LiDAR requires additional time for the flight planning, and specific data analysis user capabilities. The analysis of the satellite WorldView II MS images facilitates the landslide mapping over large areas, but at the expenses of a minor resolution to detect the smaller landslides and their boundaries. UAVs can be considered the cheapest and fastest solution for the acquisition of high resolution ortho-photographs on limited areas, and the best solution for a multi-temporal analysis of specific landslide phenomena. Limitations are due to (i) the needs of optimal climatic

  11. Landslide disaster avoidance: learning from Leyte (United States)

    Davies, T. R.


    On 17 February 2006 a gigantic rockslide triggered a debris avalanche that overran the barangay Guinsaugon, St. Bernard in Southern Leyte Province, Philippines, burying 154 victims, with 990 missing including 246 school children. Even with satellite imagery, GIS-based landslide susceptibility modelling and real-time meteorological and seismic data analysis, scientific prediction of every potentially fatal landslide is not possible in most parts of the world. This is particular the case in steep, unstable, densely-populated country in which heavy rain is common. So how can further events of this type be prevented from turning into disasters? A number of precursory phenomena were noted by local inhabitants at Guinsaugon: a crack around the slope that failed was noticed in May 2005; coconut trees near the northern foot of the landslide scarp began to lean increasingly in the down-slope direction in December 2005; a slope around the northern edge of the 17 February 2006 landslide scarp failed on December 17, 2005; in the 9 days prior to the rockslide, 640 mm of rain fell; 450 mm in a 3-day period. Such phenomena are commonly reported by local inhabitants before large landslides (e.g. Elm, Mayunmarca, and many others). In many cases, therefore, it is in principle possible for local people to avoid the consequences of the landslide if they know enough to act appropriately in response to the precursory phenomena. For this possibility to be realized, appropriate information must be provided to and assimilated by the local population. Useful ways of achieving this include pamphlets, video, TV and radio programs and visits from civil defence personnel. The information must be properly presented; scientific language will be ineffective. A communication pyramid, leading from government agencies to local leaders, can facilitate the rapid availability of the information to all potentially susceptible communities. If science can determine those areas not vulnerable to landslide

  12. Cross-slope Movement Patterns in Landslides (United States)

    Petley, D.; Murphy, W.; Bulmer, M. H.; Keefer, D.


    There is growing evidence that there is a significant element of cross-slope movement in many large landslide systems. These movements may result in changing states of stress between landslide blocks that can establish complex displacement patterns. Such motions, which are not considered in traditional two-dimensional limit-equilibrium analyses, are important in the investigation of a variety of landslide types, such as those triggered by earthquakes. In addition, these movements may introduce considerable errors into the interpretation of strain patterns as derived from InSAR studies. Finally, even traditional interpretation techniques may lead to the amount of total displacement being underestimated. These observations suggest that a three dimensional form of analysis may be more appropriate for large landslide complexes. The significance of such cross-slope movements are being investigated using a detailed investigation of the Lishan landslide complex in Central Taiwan. This landslide system, which was reactivated in 1990 related to the construction of a hotel. The total recorded movements have been approximately 1.5 m over an area of sliding that is estimated to be 450 m wide and 200 m long. Extensive damage has been caused to roads and buildings within the town. Remediation work has resulted largely in the stabilization of the landslide complex. Detailed geomorphological mapping has revealed that the landslide complex is composed of two main components. The first, immediately upslope of the hotel construction site, is a relatively shallow earthflow. The second, which has formed a large headscarp upslope from the main road in the centre of the town, is a deeper translational slide. Both appear to have been reactivations of previous failures. While the displacement patterns of the earthflow indicate a relatively simple downslope movement, the vectors derived from kinematic analysis of surface features have indicated that the movement of the deeper

  13. UAV Based Agricultural Planning and Landslide Monitoring

    Directory of Open Access Journals (Sweden)

    Servet Yaprak


    Full Text Available The use of Unmanned Aerial Vehicle (UAV tools has become widespread in map production, land surveying, landslide, erosion monitoring, monitoring of agricultural activities, aerial crop surveying, forest fire detection and monitoring operations. In this study, GEO 2 UAV manufactured by TEKNOMER equipped with SONY A6000 camera has been used. The flight plan have been performed with 100 m altitude, with 80% longitudinal and 60% side overlapping. Ground Control Points (GCPs have been observed with Topcon and Trimble GNSS geodetic receivers. Recorded GNSS signals have been processed with LGO V.8.4 software to get sensitive location information. 985 photos have been taken for the 344 hectares the agricultural area. 291 photos have been taken for 50 hectares the landslide area. All photos were processed by PIX4D software. For the agricultural area, 25 GCPs and for the landslide area, 8 GCPs have been included in the evaluation. 3D images were produced with pixel matching algorithms. As a result, the RMS evaluation was obtained as ±0.054 m for the agricultural area and as ±0.018 m for the landslide area. UAV images have indisputable contributions to the management of catastrophes such as landslides and earthquakes, and it is impossible to make terrestrial measurements in areas where disaster impact continues.

  14. Landslide inventory for the Little North Santiam River Basin, Oregon (United States)

    Sobieszczyk, Steven


    This geodatabase is an inventory of existing landslides in the Little North Santiam River Basin, Oregon (2009). Each landslide feature shown has been classified according to a number of specific characteristics identified at the time recorded in the GIS database. The classification scheme was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009). Several significant landslide characteristics recorded in the database are portrayed with symbology on this map. The specific characteristics shown for each landslide are the activity of landsliding, landslide features, deep or shallow failure, type of landslide movement, and confidence of landslide interpretation. These landslide characteristics are determined primarily on the basis of geomorphic features, or landforms, observed for each landslide. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey. Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

  15. The 22 March 2014 Oso landslide, Washington, USA (United States)

    Wartman, Joseph; Montgomery, David R.; Anderson, Scott A.; Keaton, Jeffrey R.; Benoît, Jean; dela Chapelle, John; Gilbert, Robert


    The Oso, Washington, USA, landslide occurred on the morning of Saturday, 22 March 2014 and claimed the lives of 43 people. The landslide began within an 200-m-high hillslope comprised of unconsolidated glacial and previous landslide/colluvial deposits; it continued as a debris avalanche/debris flow that rapidly inundated a neighborhood of 35 single-family residences. An intense three-week rainfall that immediately preceded the event most likely played a role in triggering the landslide; and other factors that likely contributed to destabilization of the landslide mass include alteration of the local groundwater recharge and hydrogeological regime from previous landsliding, weakening and alteration of the landslide mass caused by previous landsliding, and changes in stress distribution resulting from removal and deposition of material from earlier landsliding. Field reconnaissance following the event revealed six distinctive zones and several subzones that are characterized on the basis of geomorphic expression, styles of deformation, geologic materials, and the types, size, and orientation of vegetation. Seismic recording of the landslide indicate that the event was marked by several vibration-generating episodes of mass movement. We hypothesize that the landslide occurred in two stages, with the first being a sequential remobilization of existing slide masses from the most recent (2006) landslide and from an ancient slide that triggered a devastating debris avalanche/debris flow. The second stage involved headward extension into previously unfailed material that occurred in response to unloading and redirection of stresses.

  16. Landslide Susceptibility Index Determination Using Aritificial Neural Network (United States)

    Kawabata, D.; Bandibas, J.; Urai, M.


    The occurrence of landslide is the result of the interaction of complex and diverse environmental factors. The geomorphic features, rock types and geologic structure are especially important base factors of the landslide occurrence. Generating landslide susceptibility index by defining the relationship between landslide occurrence and that base factors using conventional mathematical and statistical methods is very difficult and inaccurate. This study focuses on generating landslide susceptibility index using artificial neural networks in Southern Japanese Alps. The training data are geomorphic (e.g. altitude, slope and aspect) and geologic parameters (e.g. rock type, distance from geologic boundary and geologic dip-strike angle) and landslides. Artificial neural network structure and training scheme are formulated to generate the index. Data from areas with and without landslide occurrences are used to train the network. The network is trained to output 1 when the input data are from areas with landslides and 0 when no landslide occurred. The trained network generates an output ranging from 0 to 1 reflecting the possibility of landslide occurrence based on the inputted data. Output values nearer to 1 means higher possibility of landslide occurrence. The artificial neural network model is incorporated into the GIS software to generate a landslide susceptibility map.

  17. Integration of landslide susceptibility products in the environmental plans (United States)

    Fiorucci, Federica; Reichenbach, Paola; Rossi, Mauro; Cardinali, Mauro; Guzzetti, Fausto


    Landslides are one of the most destructive natural hazard that causes damages to urban area worldwide. The knowledge of where a landslide could occur is essential for the strategic management of the territory and for a good urban planning . In this contest landslide susceptibility zoning (LSZ) is crucial to provide information on the degree to which an area can be affected by future slope movements. Despite landslide susceptibility maps have been prepared extensively during the last decades, there are few examples of application is in the environmental plans (EP). In this work we present a proposal for the integration of the landslide inventory map with the following landslide susceptibility products: (i) landslide susceptibility zonation , (ii) the associated error map and (iii) the susceptibility uncertainty map. Moreover we proposed to incorporate detailed morphological studies for the evaluation of landslide risk associated to local parceling plan. The integration of all this information is crucial for the management of landslide risk in urban expansions forecasts. Municipality, province and regional administration are often not able to support the costs of landslide risk evaluation for extensive areas but should concentrate their financial resources to specific hazardous and unsafe situations defined by the result of the integration of landslide susceptibility products. Zonation and detail morphological analysis should be performed taking into account the existing laws and regulations, and could become a starting point to discuss new regulations for the landslide risk management.

  18. Spatial prediction of landslide hazard using discriminant analysis and GIS (United States)

    Peter V. Gorsevski; Paul Gessler; Randy B. Foltz


    Environmental attributes relevant for spatial prediction of landslides triggered by rain and snowmelt events were derived from digital elevation model (DEM). Those data in conjunction with statistics and geographic information system (GIS) provided a detailed basis for spatial prediction of landslide hazard. The spatial prediction of landslide hazard in this paper is...

  19. Numerical modeling of landslides and generated seismic waves: The Bingham Canyon Mine landslides (United States)

    Miallot, H.; Mangeney, A.; Capdeville, Y.; Hibert, C.


    Landslides are important natural hazards and key erosion processes. They create long period surface waves that can be recorded by regional and global seismic networks. The seismic signals are generated by acceleration/deceleration of the mass sliding over the topography. They consist in a unique and powerful tool to detect, characterize and quantify the landslide dynamics. We investigate here the processes at work during the two massive landslides that struck the Bingham Canyon Mine on the 10th April 2013. We carry a combined analysis of the generated seismic signals and the landslide processes computed with a 3D modeling on a complex topography. Forces computed by broadband seismic waveform inversion are used to constrain the study and particularly the force-source and the bulk dynamic. The source time function are obtained by a 3D model (Shaltop) where rheological parameters can be adjusted. We first investigate the influence of the initial shape of the sliding mass which strongly affects the whole landslide dynamic. We also see that the initial shape of the source mass of the first landslide constrains pretty well the second landslide source mass. We then investigate the effect of a rheological parameter, the frictional angle, that strongly influences the resulted computed seismic source function. We test here numerous friction laws as the frictional Coulomb law and a velocity-weakening friction law. Our results show that the force waveform fitting the observed data is highly variable depending on these different choices.

  20. Landslide Susceptibility Mapping Based on Selected Optimal Combination of Landslide Predisposing Factors in a Large Catchment

    Directory of Open Access Journals (Sweden)

    Qianqian Wang


    Full Text Available Landslides are usually initiated under complex geological conditions. It is of great significance to find out the optimal combination of predisposing factors and create an accurate landslide susceptibility map based on them. In this paper, the Information Value Model was modified to make the Modified Information Value (MIV Model, and together with GIS (Geographical Information System and AUC (Area Under Receiver Operating Characteristic Curve test, 32 factor combinations were evaluated separately, and factor combination group with members Slope, Lithology, Drainage network, Annual precipitation, Faults, Road and Vegetation was selected as the optimal combination group with an accuracy of 95.0%. Based on this group, a landslide susceptibility zonation map was drawn, where the study area was reclassified into five classes, presenting an accurate description of different levels of landslide susceptibility, with 79.41% and 13.67% of the validating field survey landslides falling in the Very High and High zones, respectively, mainly distributed in the south and southeast of the catchment. It showed that MIV model can tackle the problem of “no data in subclass” well, generate the true information value and show real running trend, which performs well in showing the relationship between predisposing factors and landslide occurrence and can be used for preliminary landslide susceptibility assessment in the study area.

  1. Landslide-Generated Waves in a Dam Reservoir: The Effects of Landslide Rheology and Initial Submergence (United States)

    Yavari Ramsheh, S.; Ataie-Ashtiani, B.


    Recent studies revealed that landslide-generated waves (LGWs) impose the largest tsunami hazard to our shorelines although earthquake-generated waves (EGWs) occur more often. Also, EGWs are commonly followed by a large number of landslide hazards. Dam reservoirs are more vulnerable to landslide events due to being located in mountainous areas. Accurate estimation of such hazards and their destructive consequences help authorities to reduce their risks by constructive measures. In this regard, a two-layer two-phase Coulomb mixture flow (2LCMFlow) model is applied to investigate the effects of landslide characteristics on LGWs for a real-sized simplification of the Maku dam reservoir, located in the North of Iran. A sensitivity analysis is performed on the role of landslide rheological and constitutive parameters and its initial submergence in LGW characteristics and formation patterns. The numerical results show that for a subaerial (SAL), a semi-submerged (SSL), and a submarine landslide (SML) with the same initial geometry, the SSLs can create the largest wave crest, up to 60% larger than SALs, for dense material. However, SMLs generally create the largest wave troughs and SALs travel the maximum runout distances beneath the water. Regarding the two-phase (solid-liquid) nature of the landslide, when interestial water is isolated from the water layer along the water/landslide interface, a LGW with up to 30% higher wave crest can be created. In this condition, increasing the pore water pressure within the granular layer results in up to 35% higher wave trough and 40% lower wave crest at the same time. These results signify the importance of appropriate description of two-phase nature and rheological behavior of landslides in accurate estimation of LGWs which demands further numerical, physical, and field studies about such phenomena.

  2. A logical framework for ranking landslide inventory maps (United States)

    Santangelo, Michele; Fiorucci, Federica; Bucci, Francesco; Cardinali, Mauro; Ardizzone, Francesca; Marchesini, Ivan; Cesare Mondini, Alessandro; Reichenbach, Paola; Rossi, Mauro; Guzzetti, Fausto


    Landslides inventory maps are essential for quantitative landslide hazard and risk assessments, and for geomorphological and ecological studies. Landslide maps, including geomorphological, event based, multi-temporal, and seasonal inventory maps, are most commonly prepared through the visual interpretation of (i) monoscopic and stereoscopic aerial photographs, (ii) satellite images, (iii) LiDAR derived images, aided by more or less extensive field surveys. Landslide inventory maps are the basic information for a number of different scientific, technical and civil protection purposes, such as: (i) quantitative geomorphic analyses, (ii) erosion studies, (iii) deriving landslide statistics, (iv) urban development planning (v) landslide susceptibility, hazard and risk evaluation, and (vi) landslide monitoring systems. Despite several decades of activity in landslide inventory making, still no worldwide-accepted standards, best practices and protocols exist for the ranking and the production of landslide inventory maps. Standards for the preparation (and/or ranking) of landslide inventories should indicate the minimum amount of information for a landslide inventory map, given the scale, the type of images, the instrumentation available, and the available ancillary data. We recently attempted at a systematic description and evaluation of a total of 22 geomorphological inventories, 6 multi-temporal inventories, 10 event inventories, and 3 seasonal inventories, in the scale range between 1:10,000 and 1:500,000, prepared for areas in different geological and geomorphological settings. All of the analysed inventories were carried out by using image interpretation techniques, or field surveys. Firstly, a detailed characterisation was performed for each landslide inventory, mainly collecting metadata related (i) to the amount of information used for preparing the landslide inventory (i.e. images used, instrumentation, ancillary data, digitalisation method, legend, validation


    Energy Technology Data Exchange (ETDEWEB)

    David A. King


    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy’s (DOE’s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. The goal is to obtain all media no-further-investigation (NFI) determinations for the subject parcels considering existing soils. To augment the existing soils-only NFI determinations, samples of groundwater, surface water, soil, and sediment were collected to support all media NFI decisions. The only updates presented here are those that were made after the original issuance of the NFI documents. In the subject parcel where the soils NFI determination was not completed for approval (Parcel 21d), the full process has been performed to address the soils as well. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only NFI

  4. Assessing Landslide Characteristics and Developing a Landslide Potential Hazard Map in Rwanda and Uganda Using NASA Earth Observations (United States)

    Sinclair, L.; Conner, P.; le Roux, J.; Finley, T.


    The International Emergency Disasters Database indicates that a total of 482 people have been killed and another 27,530 have been affected by landslides in Rwanda and Uganda, although the actual numbers are thought to be much higher. Data for individual countries are poorly tracked, but hotspots for devastating landslides occur throughout Rwanda and Uganda due to the local topography and soil type, intense rainfall events, and deforestation. In spite of this, there has been little research in this region that utilizes satellite imagery to estimate areas susceptible to landslides. This project utilized Landsat 8 Operational Land Imager (OLI) data and Google Earth to identify landslides that occurred within the study area. These landslides were then added to SERVIR's Global Landslide Catalog (GLC). Next, Landsat 8 OLI, the Tropical Rainfall Measuring Mission (TRMM), the Global Precipitation Measurement (GPM), and Shuttle Radar Topography Mission Version 2 (SRTM V2) data were used to create a Landslide Susceptibility Map. This was combined with population data from the Socioeconomic Data and Applications Center (SEDAC) to create a Landslide Hazard map. A preliminary assessment of the relative performance of GPM and TRMM in identifying landslide conditions was also performed. The additions to the GLC, the Landslide Susceptibility Map, the Landslide Hazard Map, and the preliminary assessment of satellite rainfall performance will be used by SERVIR and the Regional Centre for Mapping of Resources for Development (RCMRD) for disaster risk management, land use planning, and determining landslide conditions and moisture thresholds.

  5. Multidisciplinary study on anthropogenic landslides in Nepal (United States)

    Puglia, Christopher; Derron, Marc-Henri; Nicolet, Pierrick; Sudmeier-Rieux, Karen; Jaboyedoff, Michel; Devkota, Sanjay


    Nepal is a country in which shallow landslide is a frequent phenomenon. Monsoon is the main triggering factor but anthropogenic influence is often significant too. Indeed, many infrastructures, such as roads or water pipes, are not built in a rigorous way because of a lack of funds and knowledge. In the present study we examine the technical, social and economic issues of landslide management for two sites in Nepal. The first site is located in Sanusiruwari VDC (Sindhupalchock district, central Nepal) and the second one in Namadi VDC (Ramecchap district, central Nepal). Both sites are affected by landslides induced by the construction of hydropower plants. These landslides may threaten the viability of the hydropower plants. At both sites the problems are quite similar, but the first site project is a private one and the second one is a public one implemented by the United Nations Development Programme (UNDP). For both sites, bioengineering methods using Vetiver (Vetyveria zizanioides) plantations is the main stabilization measure. To follow the progression of both landslides, fieldwork observations were conducted before and after the 2012 rainy season, including photogrammetric and distancemeter acquisitions. Main issues were discussed with communities and stakeholders of the hydropower projects through interviews and participatory risk mapping. Main issues include: lack of communication between the project managers and communities leading to conflict and the lack of maintenance of the bio-engineering sites, leading to less effective Vetiver growth and slope stabilization. Comparing the landslide management (technical, social and economic) of the two projects allows to point out some specific issues within an integrated risk perspective.

  6. Tracer techniques in landslide area surveys

    Energy Technology Data Exchange (ETDEWEB)

    Turcek, P [Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia)


    One of the most important effects leading to slope movements is the action of surface and ground water on rocks. The rock movement usually occurs as a result of dilatation. The increased rock porosity in the area of the slide zone leads to higher permeability. The measurement of the ground water flow rate by the single borehole method using the /sup 131/I radiotracer in objects with perforated casings, installed in the landslide zone, can be used to locate sliding surfaces. The method was successfully applied in landslides at Miksova, Turany, Liskova and Podhradi where drainage measures were taken, the efficiency of which can be checked periodically.

  7. Evaluation of landslide monitoring in the Polish Carpathians (United States)

    Collins, Brian D.; Baum, Rex L.; Mrozek, Teresa; Nescieruk, Piotr; Perski, Zbigniew; Raczkowski, Wojciech; Graniczny, Marek


    In response to the June 15, 2010 request from the Polish Geological Institute (PGI) to the U.S. Geological Survey (USGS) for assistance and advice regarding real-time landslide monitoring, landslide specialists from the USGS Landslide Hazard Program visited PGI headquarters and field sites in September 2010. During our visit we became familiar with characteristics of landslides in the Polish Carpathians, reviewed PGI monitoring techniques, and assessed needs for monitoring at recently activated landslides. Visits to several landslides that are monitored by PGI (the Just, Hańczowa, Szymbark, Siercza and Łasńica landslides) revealed that current data collection (monthly GPS and inclinometer surveys, hourly piezometers readings) is generally sufficient for collecting basic information about landslide displacement, depth, and groundwater conditions. Large landslides are typically hydrologically complex, and we would expect such complexity in Carpathian landslides, given the alternating shale and sandstone stratigraphy and complex geologic structures of the flysch bedrock. Consequently groundwater observations could be improved by installing several piezometers that sample the basal shear zone of each landslide being monitored by PGI. These could be supplemented by additional piezometers at shallower depths to help clarify general flow directions and hydraulic gradients. Remedial works at Hańczowa

  8. Rainstorms as a landslide-triggering factor in Slovenia

    Directory of Open Access Journals (Sweden)

    Marko Komac


    Full Text Available Rainfall plays an important role in the landslide triggering processes. Analyses of landslide occurrence in the area of Slovenia have shown that areas where intensive rainstorms occure (maximal daily rainfall for the 100 years period, and where the geologicalsettings are favourable, abundance of landslide can be expected. This clearly indicates the spatial and temporal dependence of landslide occurrence upon the intensive rainfall. Regarding the landslide occurrence, the intensity of maximal daily and average annual rainfall for the the 30 years period were analysed. Results have shown that daily rainfall intensity, which significantly influences the triggering of landslides, ranges from 100 to 150 mm, most probably above 130 mm. Despite the vague influence, if any at all,of the average annual rainfall, the threshold above which significant number of landslides occurs is 1000 mm.

  9. Analysis of Landslide Hazard Impact Using the Landslide Database for Germany (United States)

    Klose, M.; Damm, B.


    The Federal Republic of Germany has long been among the few European countries that lack a national landslide database. Systematic collection and inventory of landslide data still shows a comprehensive research history in Germany, but only one focused on development of databases with local or regional coverage. This has changed in recent years with the launch of a database initiative aimed at closing the data gap existing at national level. The present contribution reports on this project that is based on a landslide database which evolved over the last 15 years to a database covering large parts of Germany. A strategy of systematic retrieval, extraction, and fusion of landslide data is at the heart of the methodology, providing the basis for a database with a broad potential of application. The database offers a data pool of more than 4,200 landslide data sets with over 13,000 single data files and dates back to 12th century. All types of landslides are covered by the database, which stores not only core attributes, but also various complementary data, including data on landslide causes, impacts, and mitigation. The current database migration to PostgreSQL/PostGIS is focused on unlocking the full scientific potential of the database, while enabling data sharing and knowledge transfer via a web GIS platform. In this contribution, the goals and the research strategy of the database project are highlighted at first, with a summary of best practices in database development providing perspective. Next, the focus is on key aspects of the methodology, which is followed by the results of different case studies in the German Central Uplands. The case study results exemplify database application in analysis of vulnerability to landslides, impact statistics, and hazard or cost modeling.

  10. Landslide Susceptibility Statistical Methods: A Critical and Systematic Literature Review (United States)

    Mihir, Monika; Malamud, Bruce; Rossi, Mauro; Reichenbach, Paola; Ardizzone, Francesca


    Landslide susceptibility assessment, the subject of this systematic review, is aimed at understanding the spatial probability of slope failures under a set of geomorphological and environmental conditions. It is estimated that about 375 landslides that occur globally each year are fatal, with around 4600 people killed per year. Past studies have brought out the increasing cost of landslide damages which primarily can be attributed to human occupation and increased human activities in the vulnerable environments. Many scientists, to evaluate and reduce landslide risk, have made an effort to efficiently map landslide susceptibility using different statistical methods. In this paper, we do a critical and systematic landslide susceptibility literature review, in terms of the different statistical methods used. For each of a broad set of studies reviewed we note: (i) study geography region and areal extent, (ii) landslide types, (iii) inventory type and temporal period covered, (iv) mapping technique (v) thematic variables used (vi) statistical models, (vii) assessment of model skill, (viii) uncertainty assessment methods, (ix) validation methods. We then pulled out broad trends within our review of landslide susceptibility, particularly regarding the statistical methods. We found that the most common statistical methods used in the study of landslide susceptibility include logistic regression, artificial neural network, discriminant analysis and weight of evidence. Although most of the studies we reviewed assessed the model skill, very few assessed model uncertainty. In terms of geographic extent, the largest number of landslide susceptibility zonations were in Turkey, Korea, Spain, Italy and Malaysia. However, there are also many landslides and fatalities in other localities, particularly India, China, Philippines, Nepal and Indonesia, Guatemala, and Pakistan, where there are much fewer landslide susceptibility studies available in the peer-review literature. This

  11. Landslide susceptibility analysis using Probabilistic Certainty Factor ...

    Indian Academy of Sciences (India)

    done using many different methods and techniques. A detailed outline of .... of depressions where water is accumulated, espe- cially when the ..... The two decision rules that must be satisfied for a good landslide .... making the susceptibility zonation relative. This is ..... tional Conference on Imaging Systems and Techniques,.

  12. The Effect of Landslide on Gas Pipeline

    Directory of Open Access Journals (Sweden)

    Valkovič Vojtech


    Full Text Available The present paper deals with the calculation of stresses on the pipeline system embedded on a flexible substrate which is burdened by a landslide. As well as taking into account the probability of the influences acting on the pipe as wall thickness, and others.

  13. Quick clay and landslides of clayey soils

    NARCIS (Netherlands)

    Khaldoun, A.; Moller, P.; Fall, A.; Wegdam, G.; de Leeuw, B.; Méheust, Y.; Fossum, J.O.; Bonn, D.


    We study the rheology of quick clay, an unstable soil responsible for many landslides. We show that above a critical stress the material starts flowing abruptly with a very large viscosity decrease caused by the flow. This leads to avalanche behavior that accounts for the instability of quick clay

  14. Landslide Caused Damages in a Gallery (United States)

    Poisel, R.; Mair am Tinkhof, K.; Preh, A.


    On October 5th, 2010, cracks were found in a gallery 1.8 m high and 1.4 m wide. The gallery is 100 years old, runs parallel to a valley flank and was excavated in a tectonically strongly stressed, weathered and slightly dipping sandwich of clayey shales, sandstones and marls. The cracks in the roof as well as in the invert ran parallel to the axis of the gallery. Monitoring showed that crack widths were increasing 1.5 mm per year, sidewall distances were increasing 3.5 mm per year, whereas the height of the gallery was decreasing 2.5 mm per year. After eliminating several possible causes of cracking, a landslide producing the damages had to be taken into consideration. Monitoring of the valley flank surface as well as inclinometer readings revealed that a landslide was occurring, loading the gallery lining. Most probably the landslide had been reactivated by excessive rainfall in 2009 as well as by works for the renewal of a weir in the valley bottom. As stabilization of the slope was not an option for several reasons, it was decided to replace the gallery by a new one deeper inside the slope, which will be ready for operation in 2017. Thus the old gallery has to be kept in operation till then and it was decided to reinforce the old gallery by a heavily reinforced shotcrete lining 10 cm thick. As slope displacements went on, cracks in the shotcrete lining developed with a completely different pattern: in the section where the gallery lies completely in the landslide shear zone no cracks formed until now due to heavy reinforcement, whereas in the transition sections stable ground-landslide and landslide-stable ground diagonal tension cracks in the roof due to shear by the landslide developed. Numerical models showed that cracking and spalling of the shotcrete lining would occur only after some centimetres of additional displacements of the slope, which hopefully will not occur before 2017.

  15. A Critical Review of Landslide Failure Mechanisms (United States)

    Stead, D.; Wolter, A.; Clague, J. J.


    During the last ten years several comprehensive geotechnical studies have been completed on major historic landslides including Randa in Switzerland, Frank in Canada, Aknes in Norway, La Clapiere in France and Vaiont in Italy. In addition, numerous researchers have documented deep-seated gravitational deformations and a wide variety of large prehistoric rock slope failures. The information provided by these studies is evidence of the significant advances made in our ability to map, monitor and model landslides. Over the same period, the mining industry has developed large open pits with slope heights exceeding 1000 m that provide important analogues to high mountain slopes. In this paper we analyse data from the literature to illustrate the importance of brittle fracture, 3D controls, anisotropy, overburden stress, geomorphic processes, groundwater and temperature in major landslides and provide some indicators as to the research required to further understand the complexity of rock slope failure mechanisms. The nature of the landslide failure surface has received inadequate attention in the past, with failure surfaces typically considered in 2D and simulated as discrete, smooth and often planar features. Current work shows that failure surfaces are inherently three-dimensional and have much structural variability across the area of the landslide scarp, reflecting complex structural histories. Such anisotropy and variations may result in multiple events or distinct blocks that move at different rates. Just as most failure surfaces vary spatially, they may also change with depth and thus should more realistically be considered failure zones rather than discrete surfaces. The increasing recognition of the importance of step-path failures, internal dilation and brittle fracture are indicative of the complexity in slope failure surfaces. Related to the variation in failure surface characteristics is the importance of 3D rotational displacements and both the

  16. Guidance Index for Shallow Landslide Hazard Analysis

    Directory of Open Access Journals (Sweden)

    Cheila Avalon Cullen


    Full Text Available Rainfall-induced shallow landslides are one of the most frequent hazards on slanted terrains. Intense storms with high-intensity and long-duration rainfall have high potential to trigger rapidly moving soil masses due to changes in pore water pressure and seepage forces. Nevertheless, regardless of the intensity and/or duration of the rainfall, shallow landslides are influenced by antecedent soil moisture conditions. As of this day, no system exists that dynamically interrelates these two factors on large scales. This work introduces a Shallow Landslide Index (SLI as the first implementation of antecedent soil moisture conditions for the hazard analysis of shallow rainfall-induced landslides. The proposed mathematical algorithm is built using a logistic regression method that systematically learns from a comprehensive landslide inventory. Initially, root-soil moisture and rainfall measurements modeled from AMSR-E and TRMM respectively, are used as proxies to develop the index. The input dataset is randomly divided into training and verification sets using the Hold-Out method. Validation results indicate that the best-fit model predicts the highest number of cases correctly at 93.2% accuracy. Consecutively, as AMSR-E and TRMM stopped working in October 2011 and April 2015 respectively, root-soil moisture and rainfall measurements modeled by SMAP and GPM are used to develop models that calculate the SLI for 10, 7, and 3 days. The resulting models indicate a strong relationship (78.7%, 79.6%, and 76.8% respectively between the predictors and the predicted value. The results also highlight important remaining challenges such as adequate information for algorithm functionality and satellite based data reliability. Nevertheless, the experimental system can potentially be used as a dynamic indicator of the total amount of antecedent moisture and rainfall (for a given duration of time needed to trigger a shallow landslide in a susceptible area. It is

  17. A proposed cell model for multiple-occurrence regional landslide events: Implications for landslide susceptibility mapping (United States)

    Crozier, M. J.


    Multiple-occurrence regional landslide events (MORLEs) consist of hundreds to thousands of shallow landslides occurring more or less simultaneously within defined areas, ranging from tens to thousands of square kilometres. While MORLEs can be triggered by rainstorms and earthquakes, this paper is confined to those landslide events triggered by rainstorms. Globally, MORLEs occur in a range of geological settings in areas of moderate to steep slopes subject to intense rainstorms. Individual landslides in rainstorm-triggered events are dominantly small, shallow debris and earth flows, and debris and earth slides involving regolith or weathered bedrock. The model used to characterise these events assumes that energy distribution within the event area is represented on the land surface by a cell structure; with maximum energy expenditure within an identifiable core and rapid dissipation concentrically away from the centre. The version of the model presented here has been developed for rainfall-triggered landslide events. It proposes that rainfall intensity can be used to determine different critical landslide response zones within the cell (referred to as core, middle, and periphery zones). These zones are most readily distinguished by two conditions: the proportion of the slope that fails and the particular type of the slope stability factor that assumes dominance in determining specific sites of landslide occurrence. The latter condition means that the power of any slope stability factor to distinguish between stable and unstable sites varies throughout the affected area in accordance with the landslide response zones within the cell; certain factors critical for determining the location of landslide sites in one part of the event area have little influence in other parts of the event area. The implication is that landslide susceptibility maps (and subsequently derived mitigation measures) based on conventional slope stability factors may have only limited validity

  18. Landslides in Flanders (Belgium): Where science meets public policy (United States)

    van den Eeckhaut, M.; Poesen, J.; Vandekerckhove, L.


    Although scientific research on landslides in the Flemish Ardennes (710 km²; Belgium), has been conducted over the last decades, the Flemish Government only took account of slope failure as a soil degradation process after the occurrence of several damaging landslides in the beginning of the 21st century. Here we aim to present the successful collaboration between the Physical and Regional Geography Research Group (FRG; Dept. Earth and Environmental Sciences K.U.Leuven) and the Environment, Nature and Energy Department (LNE; Flemish Government) in landslide management. We will demonstrate how geomorphologists produced practical tools for landslide management which can be directly applied by LNE as well as other local and regional authorities and planners. Since 2004 three projects on landslide inventory mapping and susceptibility assessment in the Flemish Ardennes have been funded by LNE, and a fourth one on landslide susceptibility assessment in remaining hilly regions in Flanders west of Brussels recently started. Together with a steering committee composed of stakeholders, persons from LNE supervise the research carried out by geomorphologists experienced in landslide studies. For the establishment of the landslide inventory map of the Flemish Ardennes we combined the analysis of LIDAR-derived hillshade and contour line maps with detailed field controls. Additional information was collected through interviews with local authorities and inhabitants and from analysis of newspaper articles and technical reports. Then, a statistical model, logistic regression, was applied to produce a high quality classified landslide susceptibility map. The unique part of this collaboration is that all end products are online available at user-friendly websites designed by LNE. The scientific report containing (1) general information on landslides, (2) a description of the study area, (3) an explanation of the materials and methods used, (4) a presentation of the resulting

  19. Landslides in the western Columbia Gorge, Skamania County, Washington (United States)

    Pierson, Thomas C.; Evarts, Russell C.; Bard, Joseph A.


    SummaryRecent light detection and ranging (lidar) imagery has allowed us to identify and map a large number of previously unrecognized landslides, or slides, in heavily forested terrain in the western Columbia Gorge, Skamania County, Washington, and it has revealed that the few previously recognized areas of instability are actually composites of multiple smaller landslides. The high resolution of the imagery further reveals that landslides in the map area have complex movement histories and span a wide range of relative ages. Movement histories are inferred from relative landslide locations and crosscutting relations of surface features. Estimated age ranges are based on (1) limited absolute dating; (2) relative fineness of landscape surface textures, calibrated by comparison with surfaces of currently active and dated landslides as interpreted from interferometric synthetic aperture radar (InSAR), global positioning system (GPS), and historical records; (3) sharpness and steepness of larger-scale surface morphologic features, calibrated by comparison with similar dated features in other regions; (4) degree of surface erosion; and (5) evidence of erosion or deposition by late Pleistocene (15–22 ka) Missoula floods at or below 200 m altitude. The relative age categories are recent (0 to ~1,000 years old), intermediate-age (~1,000 to ~15,000 years old), and old (>~15,000 years old). Within the 221.5 km2 map area, we identified 215 discrete landslides, covering 140.9 km2 (64 percent of the map area). At least 12 of the recent landslides are currently moving or have moved within the last two decades. Mapping for this study expanded the area of previously recognized unstable terrain by 56 percent. Landslide geometries suggest that more than half (62 percent) of these slope failures are translational landslides or composite landslides with translational elements, with failure occurring along gently sloping bedding planes in zones of deeply weathered, locally clay rich

  20. Landslide mobility and hazards: implications of the 2014 Oso disaster (United States)

    Iverson, R. M.; George, D. L.; Allstadt, K.; Reid, M. E.; Collins, B. D.; Vallance, J. W.; Schilling, S. P.; Godt, J. W.; Cannon, C. M.; Magirl, C. S.; Baum, R. L.; Coe, J. A.; Schulz, W. H.; Bower, J. B.


    Landslides reflect landscape instability that evolves over meteorological and geological timescales, and they also pose threats to people, property, and the environment. The severity of these threats depends largely on landslide speed and travel distance, which are collectively described as landslide "mobility". To investigate causes and effects of mobility, we focus on a disastrous landslide that occurred on 22 March 2014 near Oso, Washington, USA, following a long period of abnormally wet weather. The landslide's impacts were severe because its mobility exceeded that of prior historical landslides at the site, and also exceeded that of comparable landslides elsewhere. The ∼ 8 ×106 m3 landslide originated on a gently sloping (<20°) riverside bluff only 180 m high, yet it traveled across the entire ∼1 km breadth of the adjacent floodplain and spread laterally a similar distance. Seismological evidence indicates that high-speed, flowing motion of the landslide began after about 50 s of preliminary slope movement, and observational evidence supports the hypothesis that the high mobility of the landslide resulted from liquefaction of water-saturated sediment at its base. Numerical simulation of the event using a newly developed model indicates that liquefaction and high mobility can be attributed to compression- and/or shear-induced sediment contraction that was strongly dependent on initial conditions. An alternative numerical simulation indicates that the landslide would have been far less mobile if its initial porosity and water content had been only slightly lower. Sensitive dependence of landslide mobility on initial conditions has broad implications for assessment of landslide hazards.

  1. Main components and characteristics of landslide early warning systems operational worldwide (United States)

    Piciullo, Luca; Cepeda, José


    addressed and variables to be considered for correlations. The characteristics of LEWSs at local scale are strongly affected by numerous constraints and factors, from time to time different, related to the characteristics of the problem they address. Monitoring measures, variables and correlation laws considered for the design and employment of local LEWSs, strongly depends on the type of landslide to be addressed. On the other hand, territorial LEWSs mainly deals with rainfall-induced landslides characterized by fast slope movement. These systems have become a risk management approach, employed worldwide over areas of relevant extension. Before 2005 only few experiences of LEWSs at a regional scale were carried out, such as in: Hong Kong, China; Zhejiang Province, China; San Francisco Bay, California, USA; Appalachians, USA; Oregon, USA; Rio de Janeiro, Brazil. Since the beginning of the XXI century, increased knowledge on rainfall-landslide correlations and upgraded technologies in weather forecast have promoted the development and improvement of territorial LEWSs around the world.

  2. Precursory Seismicity Associated With Landslides, Including the 2017 Tsunamigenic Landslide in the Karrat Fjord, Greenland (United States)

    Caplan-Auerbach, J.


    On the evening of June 17 2017, a massive landslide fell from the wall of the Karrat Fjord, Greenland, generating a tsunami that caused the deaths of four residents in the nearby village of Nuugaatsiaq. The slide took place at a bluff 30 km from the village, where a broadband seismometer (DK.NUUG) is permanently deployed. The landslide generated a seismic signal initially interpreted as a magnitude 4.1 earthquake, as well as a tsunami that initially reached heights exceeding 100 m. Prior to the large seismic signal, however, station NUUG detected a series of several dozen small pulses, most of which were highly similar in time series. The pulses occur more frequently with time, until they effectively merge with the seismic signal of the landslide. The pulses were not detected on any other seismic stations, so their source locations cannot be calculated, but particle motions suggest that they were coming from an azimuth of 30o, consistent with the location of the landslide relative to Nuugaatsiaq. This particular sequence, in which small, repeating earthquakes occur with increasing frequency prior to a landslide, has been observed in at least four other locations: (1) on Mt. Baker (Washington) during an ice avalanche in 1976 (Weaver and Malone, 1979), (2) repeatedly on Iliamna volcano (Alaska) in association with glacial avalanches (Caplan-Auerbach and Huggel, 2007), (3) on Mt. Stellar (Alaska) prior to a 2006 rockfall (Huggel et al., 2010), and (4) as part of the Kausu landslide (Japan), in 2015 (Yamada et al., 2016). In all cases the precursory events exhibited waveform similarity, indicative of a repeating point of failure. These events represent stick-slip behavior at the landslide base. The precursory sequences last several hours, suggesting that detection of these events could provide a means of warning prior to failure. This may be useful in areas where instabilities or incipient failures are evident.

  3. Prediction of Rainfall-Induced Landslides (United States)

    Nadim, F.; Sandersen, F.


    Rainfall-induced landslides can be triggered by two main mechanisms: shear failure due to build-up of pore water pressure and erosion by surface water runoff when flow velocity exceeds a critical value. Field measurements indicate that, in the initial phase, the slip surface of a landslide often occurs along the top of a relatively impermeable layer located at some depth within the soil profile, e.g. at the contact with a shallow underlying bedrock or parent rock. The shear strength along this surface and hence the stability of the slope is governed by the pore water pressure. The pore pressure is in turn controlled by water seepage through the slope, either from infiltrated rain, or from groundwater that follows bedrock joints and soil layers with high permeability. When the infiltration rate of the underlying layer is too low for further downward penetration of water or when a wetting front is produced, pore water pressure builds up, reducing the soil shear strength. During high intensity rainfall, surface water runoff will exert shear stresses on the bed material. De-pending on the grain size distribution and specific gravity of the material, erosion might occur when the flow velocity exceeds a critical value. As erosion progresses and sediment concentration increases, the flow regime may become unstable with heavy erosion at high flow velocity locations triggering a debris flow. In many cases, previous landslides along steep gully walls have fed an abundance of loose soil material into the gullies. Landslides along gully walls that obstruct the water transport may also trigger debris flows when the landslide-dam collapses, creating a surge downstream. Both the long-duration (1 or more days) and short-duration precipitation (of the order of 1 hour) are significant in the triggering of shallow landslides, since the critical short-duration rainfall intensity reduces as the antecedent accumulated rainfall increases. Experiences in Norway indicate that the maxi

  4. Global Scale Analysis of Martian Landslide Mobility and Paleoenvironmental Clues (United States)

    Crosta, Giovanni Battista; De Blasio, Fabio Vittorio; Frattini, Paolo


    The mobility of landslides on Mars is studied based on a database of 3,118 events. To establish the volume of the landslides for the whole data set based on the deposit area, a new volume-area relationship based on a representative data set of 222 landslides is used. By plotting the H/L ratio between fall height H and runout L versus volume, the landslide mobility is analyzed and compared with existing empirical relationships for Martian and terrestrial landslides. By analyzing the mobility in terms of normalized residuals, that is, the relative deviation of the H/L ratio from the data set best-fit line, mobility is found to depend on both the landslide location on Mars and the landslide typology. This allows us to identify four different types of high-mobility (hypermobile) landslides. Three classes of high-mobility landslides are associated respectively to meteoroid impact, the Olympus Mons aureoles, and landslides with Toreva-block failure style, and their mobility can be explained by the peculiar flow mechanics. The fourth class includes landslides associated with isolated craters, those in the regions wetted by the putative Oceanus Borealis, and the ones at high latitudes. We suggest that the common factor behind all the hypermobile landslides of this fourth kind is the presence of ice. This is confirmed by our data showing that landslides increase in mobility with latitude. The latitudinal trend mirrors the distribution of ice as detected by radar, neutron probes, and the presence of glacial and layered ejecta morphologies. Because the overall landslide distribution supports the presence of ice-lubricated conditions, two ice lubrication models are presented showing how ice melting within or underneath the landslides could enhance mobility. By proper analysis in terms of apparent friction residuals, we find that the mobility of landslides in Valles Marineris with the largest landslide concentration is lower than average. We explain this circumstance partly


    DEFF Research Database (Denmark)

    Engholm, Ida


    Celebrated as one of the leading and most valuable brands in the world, eBay has acquired iconic status on par with century-old brands such as Coca-Cola and Disney. The eBay logo is now synonymous with the world’s leading online auction website, and its design is associated with the company...

  6. Challenges for landslide hazard and risk management in ‘low-risk’ regions, Czech Republic—landslide occurrences and related costs (IPL project no. 197)

    Czech Academy of Sciences Publication Activity Database

    Klimeš, Jan; Stemberk, Jakub; Blahůt, Jan; Krejčí, V.; Krejčí, O.; Hartvich, Filip; Kycl, P.


    Roč. 14, č. 2 (2017), s. 771-780 ISSN 1612-510X R&D Projects: GA MŠk(CZ) LG15007 Institutional support: RVO:67985891 Keywords : landslide inventory * ICL/IPL activities * landslide cost * landslide risk * fatal landslides * public awareness Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Physical geography Impact factor: 3.657, year: 2016

  7. Submarine Landslides: What we Know and Where we are Going! (United States)

    Moscardelli, L. G.; Mountjoy, J. J.; Micallef, A.; Strasser, M.; Vanneste, M.; Chaytor, J. D.; Mosher, D.; Krastel, S.; Lo Iacono, C.; Yamada, Y.


    Submarine landslides and other gravity-induced movements can disrupt very large areas of continental margins resulting in long-term seafloor morphologic change and multi-scale mass transport deposits (MTDs). Potential consequences of submarine landslides include damage to seabed infrastructure, offshore facilities, as well as generation or enhancement of tsunamis. MTDs are common on the modern seafloor and within the stratigraphic record. Slides, slumps and debris flows can be constituents of MTDs and can co-occur in the same event or depositional unit. Recent research indicates that relationships exist between MTD geological setting, causal mechanisms, and geometries. Quantitative data analysis suggests that MTD morphometric parameters can be used to link these three parameters. Despite many advances in this field, it still remains unclear how to definitively identify pre-conditioning factors and triggers of submarine landslides in modern slopes, and how submarine landslides evolve after initiation. In addition, new questions regarding the interaction between submarine landslides and active marine processes, such as bottom currents and fluid flow, have emerged.One of the mandates of the S4SLIDE (IGCP-640) project, a joint endeavor of UNESCO and IGCP that represents the broad field of submarine landslide research, is to facilitate interactions at an international level among scientists, industry and government representatives to advance our knowledge on a number of outstanding science questions: (i) What is the nature of the interaction between current-controlled sedimentation and submarine landslides? (ii) What role do transient turbulent-laminar flows play in the formation of submarine landslides? (iii) Do climatic variations control the occurrence of submarine landslides? (iv) What is the economic significance of submarine landslides? (v) Do we understand the hazards that submarine landslides pose to the environment and to humans? This presentation will cover

  8. Investigating landslides caused by earthquakes - A historical review (United States)

    Keefer, D.K.


    Post-earthquake field investigations of landslide occurrence have provided a basis for understanding, evaluating, and mapping the hazard and risk associated with earthquake-induced landslides. This paper traces the historical development of knowledge derived from these investigations. Before 1783, historical accounts of the occurrence of landslides in earthquake are typically so incomplete and vague that conclusions based on these accounts are of limited usefulness. For example, the number of landslides triggered by a given event is almost always greatly underestimated. The first formal, scientific post-earthquake investigation that included systematic documentation of the landslides was undertaken in the Calabria region of Italy after the 1783 earthquake swarm. From then until the mid-twentieth century, the best information on earthquake-induced landslides came from a succession of post-earthquake investigations largely carried out by formal commissions that undertook extensive ground-based field studies. Beginning in the mid-twentieth century, when the use of aerial photography became widespread, comprehensive inventories of landslide occurrence have been made for several earthquakes in the United States, Peru, Guatemala, Italy, El Salvador, Japan, and Taiwan. Techniques have also been developed for performing "retrospective" analyses years or decades after an earthquake that attempt to reconstruct the distribution of landslides triggered by the event. The additional use of Geographic Information System (GIS) processing and digital mapping since about 1989 has greatly facilitated the level of analysis that can applied to mapped distributions of landslides. Beginning in 1984, synthesis of worldwide and national data on earthquake-induced landslides have defined their general characteristics and relations between their occurrence and various geologic and seismic parameters. However, the number of comprehensive post-earthquake studies of landslides is still

  9. Investigation of relationship between sediment yield and landslide in Iran

    Directory of Open Access Journals (Sweden)

    Samad Shadfar


    Full Text Available Landslides have been made irreversible damage to urban areas and economic in Iran. In this research, at first, for Investigation of relationship between landslide and sediment yield was recognized some of effective factors on Landslide. These Factors were processed with use of ILWIS and Arc GIS software’s. Landslide hazard zonation was done using Density Area and Index Overlay methods in GIS and evaluated them using Quality Sum index. In after phase, were determined sediment yield in each of them. Finally, occurrence rate landslide investigated in sediment yield zones. The results indicated that, slope, lithology and distance from the hydrographic network have the greatest impact on landslides. Most of the landslides have occurred in the 15-40% slope class, units of conglomerate and marl, and within one km of drainage network. On the other hand, the relationship between landslide frequency and distance of the fault was not a linear relationship and Almost 60 %of landslides have occurred distance of one km of the faults. Evaluation using Quality Sum index showed that the density Area has a more logical answer and as Appropriate method will be introduced in the basin. Investigation of deposition potential in sub-basins showed that Javaherdeh sub basin with 92.74 deposition potential is the first priority. Nedasht and latmohalleh sub basins, each with a deposition potential of 20.08 are the next priorities. Relationship between landslide area and deposition potential were identified as 8/91% of the landslides in the area of low And about 79 percent of landslides are located in high and very high deposition potentials.

  10. Investigating Landslides Caused by Earthquakes A Historical Review (United States)

    Keefer, David K.

    Post-earthquake field investigations of landslide occurrence have provided a basis for understanding, evaluating, and mapping the hazard and risk associated withearthquake-induced landslides. This paper traces thehistorical development of knowledge derived from these investigations. Before 1783, historical accounts of the occurrence of landslides in earthquakes are typically so incomplete and vague that conclusions based on these accounts are of limited usefulness. For example, the number of landslides triggered by a given event is almost always greatly underestimated. The first formal, scientific post-earthquake investigation that included systematic documentation of the landslides was undertaken in the Calabria region of Italy after the 1783 earthquake swarm. From then until the mid-twentieth century, the best information on earthquake-induced landslides came from a succession ofpost-earthquake investigations largely carried out by formal commissions that undertook extensive ground-based field studies. Beginning in the mid-twentieth century, when the use of aerial photography became widespread, comprehensive inventories of landslide occurrence have been made for several earthquakes in the United States, Peru, Guatemala, Italy, El Salvador, Japan, and Taiwan. Techniques have also been developed for performing ``retrospective'' analyses years or decades after an earthquake that attempt to reconstruct the distribution of landslides triggered by the event. The additional use of Geographic Information System (GIS) processing and digital mapping since about 1989 has greatly facilitated the level of analysis that can applied to mapped distributions of landslides. Beginning in 1984, syntheses of worldwide and national data on earthquake-induced landslides have defined their general characteristics and relations between their occurrence and various geologic and seismic parameters. However, the number of comprehensive post-earthquake studies of landslides is still

  11. Enriching Great Britain's National Landslide Database by searching newspaper archives (United States)

    Taylor, Faith E.; Malamud, Bruce D.; Freeborough, Katy; Demeritt, David


    Our understanding of where landslide hazard and impact will be greatest is largely based on our knowledge of past events. Here, we present a method to supplement existing records of landslides in Great Britain by searching an electronic archive of regional newspapers. In Great Britain, the British Geological Survey (BGS) is responsible for updating and maintaining records of landslide events and their impacts in the National Landslide Database (NLD). The NLD contains records of more than 16,500 landslide events in Great Britain. Data sources for the NLD include field surveys, academic articles, grey literature, news, public reports and, since 2012, social media. We aim to supplement the richness of the NLD by (i) identifying additional landslide events, (ii) acting as an additional source of confirmation of events existing in the NLD and (iii) adding more detail to existing database entries. This is done by systematically searching the Nexis UK digital archive of 568 regional newspapers published in the UK. In this paper, we construct a robust Boolean search criterion by experimenting with landslide terminology for four training periods. We then apply this search to all articles published in 2006 and 2012. This resulted in the addition of 111 records of landslide events to the NLD over the 2 years investigated (2006 and 2012). We also find that we were able to obtain information about landslide impact for 60-90% of landslide events identified from newspaper articles. Spatial and temporal patterns of additional landslides identified from newspaper articles are broadly in line with those existing in the NLD, confirming that the NLD is a representative sample of landsliding in Great Britain. This method could now be applied to more time periods and/or other hazards to add richness to databases and thus improve our ability to forecast future events based on records of past events.


    Wieczorek, Gerald F.; Wu, Jishan; Li, Tianchi


    Landslides historically have caused severe erosion problems in the Xiao River drainage region of northeastern Yunnan Province, China, that hence resulted in serious economic and social consequences. Owing to monsoonal storms of high rainfall intensity, the erosion potential is high in this mountainous, seismically active region. Landslides transported large quantities of materials into the ravines. During intense storms, high runoff from the deforested areas has mobilized this material into debris flows. Where these flows emerged onto flatter slopes in the lower parts of the watersheds, the channels were too small to hold them, so farmland and villages were inundated. Debris flows in this region during June-August 1985 killed 12 people, damaged roads and the main rail line to Kunming, the capital of Yunnan Province, inundated farmland, and overflowed debris-retention structures. To mitigate these severe erosion problems, several different methods have been used.

  13. Landslide monitoring in the Atlantic Highlands area, New Jersey (United States)

    Reilly, Pamela A.; Ashland, Francis X.; Fiore, Alex R.


    Shallow and deep-seated landslides have occurred episodically on the steep coastal bluffs of the Atlantic Highlands area (Boroughs of Atlantic Highlands and Highlands) in New Jersey. The oldest documented deep-seated landslide occurred in April 1782 and significantly changed the morphology of the bluff. However, recent landslides have been mostly shallow in nature and have occurred during large storms with exceptionally heavy rainfall. These shallow landslides have resulted in considerable damage to residential property and local infrastructure and threatened human safety.The recent shallow landslides in the area (locations modified from New Jersey Department of Environmental Protection) consist primarily of slumps and flows of earth and debris within areas of historical landslides or on slopes modified by human activities. Such landslides are typically triggered by increases in shallow soil moisture and pore-water pressure caused by sustained and intense rainfall associated with spring nor’easters and late summer–fall tropical cyclones. However, the critical relation between rainfall, soil-moisture conditions, and landslide movement has not been fully defined. The U.S. Geological Survey is currently monitoring hillslopes within the Atlantic Highlands area to better understand the hydrologic and meteorological conditions associated with shallow landslide initiation.

  14. Distributed modelling of shallow landslides triggered by intense rainfall

    Directory of Open Access Journals (Sweden)

    G. B. Crosta


    Full Text Available Hazard assessment of shallow landslides represents an important aspect of land management in mountainous areas. Among all the methods proposed in the literature, physically based methods are the only ones that explicitly includes the dynamic factors that control landslide triggering (rainfall pattern, land-use. For this reason, they allow forecasting both the temporal and the spatial distribution of shallow landslides. Physically based methods for shallow landslides are based on the coupling of the infinite slope stability analysis with hydrological models. Three different grid-based distributed hydrological models are presented in this paper: a steady state model, a transient "piston-flow" wetting front model, and a transient diffusive model. A comparative test of these models was performed to simulate landslide occurred during a rainfall event (27–28 June 1997 that triggered hundreds of shallow landslides within Lecco province (central Southern Alps, Italy. In order to test the potential for a completely distributed model for rainfall-triggered landslides, radar detected rainfall intensity has been used. A new procedure for quantitative evaluation of distributed model performance is presented and used in this paper. The diffusive model results in the best model for the simulation of shallow landslide triggering after a rainfall event like the one that we have analysed. Finally, radar data available for the June 1997 event permitted greatly improving the simulation. In particular, radar data allowed to explain the non-uniform distribution of landslides within the study area.

  15. Landslide tsunami hazard in the Indonesian Sunda Arc

    Directory of Open Access Journals (Sweden)

    S. Brune


    Full Text Available The Indonesian archipelago is known for the occurrence of catastrophic earthquake-generated tsunamis along the Sunda Arc. The tsunami hazard associated with submarine landslides however has not been fully addressed. In this paper, we compile the known tsunamigenic events where landslide involvement is certain and summarize the properties of published landslides that were identified with geophysical methods. We depict novel mass movements, found in newly available bathymetry, and determine their key parameters. Using numerical modeling, we compute possible tsunami scenarios. Furthermore, we propose a way of identifying landslide tsunamis using an array of few buoys with bottom pressure units.

  16. Case Histories of Landslide Impact: A Database-driven Approach (United States)

    Klose, Martin; Damm, Bodo


    Fundamental understanding of landslide risk requires in-depth knowledge of how landslides have impacted society in the past (e.g., Corominas et al., 2014). A key to obtain insights into the evolution of landslide risk at single facilities of critical infrastructures are case histories of landslide impact. The purpose of such historical analyses is to inform about the site-specific interactions between landslides and land-use activity. Case histories support correlating landslide events and associated damages with multiple control variables of landslide risk, including (i) previous construction works, (ii) hazard awareness, (iii) the type of structure or its material properties, and (iv) measures of post-disaster mitigation. It is a key advantage of case histories to provide an overview of the changes in the exposure and vulnerability of infrastructures over time. Their application helps to learn more about changing patterns in risk culture and the effectiveness of repair or prevention measures (e.g., Klose et al., 2014). Case histories of landslide impact are developed on the basis of information extracted from landslide databases. The use of path diagrams and illustrated flowcharts as data modeling techniques is aimed at structuring, condensing, and visualizing complex historical data sets on landslide activity and land-use. Much of the scientific potential of case histories simply depends on the quality of available database information. Landslide databases relying on a bottom-up approach characterized by targeted local data specification are optimally suited for historical impact analyses. Combined with systematic retrieval, extraction, and integration of data from multiple sources, landslide databases constitute a valuable tool for developing case histories that enable to open a whole new window on the study of landslide impacts (e.g., Damm and Klose, 2014). The present contribution introduces such a case history for a well-known landslide site at a heavily

  17. Geomechanical modeling of the Steinernase landslide (Switzerland)


    Laloui, Lyesse; Ferrari, Alessio; Bonnard, Christophe


    A geomechanical model was developed to analyse the behaviour of a natural slope located on the bank of the Rhine River between the towns of Stein and Mumpf in Switzerland. The slope is affected by a landslide and three strategic infrastructure assets are located at its toe. An intense monitoring campaign made it possible to identify pore water pressure evolution as the main cause for movement accelerations and to detect the presence of a multiple slip surface system. Advanced coupled finite e...

  18. Is air pollution causing landslides in China? (United States)

    Zhang, Ming; McSaveney, Mauri J.


    Air pollution in China often exceeds "unhealthy" levels, but Chinese air is not only a threat from being breathed: the pollutants may also be causing fatal landslides. Very acid rain from severe air pollution falls widely in southwest China, where coal is a major energy source. We discuss where acid rain may provide an unsuspected link between mining and the fatal 2009 Jiweishan landslide in southwest China; it may have reduced the strength of a thin, calcareous, black sapropelic shale in Jiweishan Mountain by removing cementing carbonate minerals and sapropel matrix. Mining beneath the potential slide mass may not have directly triggered the landslide, but collapse of abandoned adits drained a perched aquifer above a regional black-shale aquiclude. Inflow of acid, oxygenated water and nutrients into the aquiclude may have accelerated the reduction of strength of the weakest rocks and consequently led to rapid sliding of a large rock mass on a layer of weathered shale left composed largely of soft, and slippery talc.

  19. Seismology of the Oso-Steelhead landslide (United States)

    Hibert, C.; Stark, C. P.; Ekström, G.


    We carry out a combined analysis of the short- and long-period seismic signals generated by the devastating Oso-Steelhead landslide that occurred on 22 March 2014. The seismic records show that the Oso-Steelhead landslide was not a single slope failure, but a succession of multiple failures distinguished by two major collapses that occurred approximately three minutes apart. The first generated long-period surface waves that were recorded at several proximal stations. We invert these long-period signals for the forces acting at the source, and obtain estimates of the first failure runout and kinematics, as well as its mass after calibration against the mass-center displacement estimated from remote-sensing imagery. Short-period analysis of both events suggests that the source dynamics of the second are more complex than the first. No distinct long-period surface waves were recorded for the second failure, which prevents inversion for its source parameters. However, by comparing the seismic energy of the short-period waves generated by both events we are able to estimate the volume of the second. Our analysis suggests that the volume of the second failure is about 15-30% of the total landslide volume, which is in agreement with ground observations.


    Directory of Open Access Journals (Sweden)

    F. Albrecht


    Full Text Available Landslide mapping benefits from the ever increasing availability of Earth Observation (EO data resulting from programmes like the Copernicus Sentinel missions and improved infrastructure for data access. However, there arises the need for improved automated landslide information extraction processes from EO data while the dominant method is still manual delineation. Object-based image analysis (OBIA provides the means for the fast and efficient extraction of landslide information. To prove its quality, automated results are often compared to manually delineated landslide maps. Although there is awareness of the uncertainties inherent in manual delineations, there is a lack of understanding how they affect the levels of agreement in a direct comparison of OBIA-derived landslide maps and manually derived landslide maps. In order to provide an improved reference, we present a fuzzy approach for the manual delineation of landslides on optical satellite images, thereby making the inherent uncertainties of the delineation explicit. The fuzzy manual delineation and the OBIA classification are compared by accuracy metrics accepted in the remote sensing community. We have tested this approach for high resolution (HR satellite images of three large landslides in Austria and Italy. We were able to show that the deviation of the OBIA result from the manual delineation can mainly be attributed to the uncertainty inherent in the manual delineation process, a relevant issue for the design of validation processes for OBIA-derived landslide maps.

  1. Assessing the Agreement Between Eo-Based Semi-Automated Landslide Maps with Fuzzy Manual Landslide Delineation (United States)

    Albrecht, F.; Hölbling, D.; Friedl, B.


    Landslide mapping benefits from the ever increasing availability of Earth Observation (EO) data resulting from programmes like the Copernicus Sentinel missions and improved infrastructure for data access. However, there arises the need for improved automated landslide information extraction processes from EO data while the dominant method is still manual delineation. Object-based image analysis (OBIA) provides the means for the fast and efficient extraction of landslide information. To prove its quality, automated results are often compared to manually delineated landslide maps. Although there is awareness of the uncertainties inherent in manual delineations, there is a lack of understanding how they affect the levels of agreement in a direct comparison of OBIA-derived landslide maps and manually derived landslide maps. In order to provide an improved reference, we present a fuzzy approach for the manual delineation of landslides on optical satellite images, thereby making the inherent uncertainties of the delineation explicit. The fuzzy manual delineation and the OBIA classification are compared by accuracy metrics accepted in the remote sensing community. We have tested this approach for high resolution (HR) satellite images of three large landslides in Austria and Italy. We were able to show that the deviation of the OBIA result from the manual delineation can mainly be attributed to the uncertainty inherent in the manual delineation process, a relevant issue for the design of validation processes for OBIA-derived landslide maps.

  2. Stepwise mitigation of the Macesnik landslide, N Slovenia

    Directory of Open Access Journals (Sweden)

    M. Mikoš


    Full Text Available The paper gives an overview of the history of evolution and mitigation of the Macesnik landslide in N Slovenia. It was triggered in 1989 above the Solčava village, but it enlarged with time. In 2005, the landslide has been threatening a few residential and farm houses, as well as the panoramic road, and it is only 1000 m away from the Savinja River and the village of Solčava. It is 2500 m long and up to more than 100 m wide with an estimated volume in excess of 2 million m3. Its depth is not constant: on average it is 10 to 15 m deep, but in the area of the toe, which is retained by a rock outcrop, it reaches the depth of 30 m. The unstable mass consists of water-saturated highly-weathered carboniferous formations. The presently active landslide lies within the fossil landslide which is up to 350 m wide and 50 m deep with the total volume estimated at 8 to 10 million m3. Since 2000, the landslide has been investigated by 36 boreholes, and 28 of them were equipped with inclinometer casings, which also serve as piezometers. Surface movements have been monitored geodetically in 20 cross sections. This helped to understand the causes and mechanics of the landslide. Therefore, landslide mitigation works were planned rather to reduce the landslide movement so that the resulting damages could be minimized. The construction of mitigation works was made difficult in the 1990s due to intensive landslide movements that could reach up to 50 cm/day with an average of 25 cm/day. Since 2001, surface drainage works in the form of open surface drains have mainly been completed around the circumference of the landslide as the first phase of the mitigation works and they are regularly maintained. As a final mitigation solution, plans have been made to build a combination of subsurface drainage works in the form of deep drains with retaining works in the form of concrete vertical shafts functioning as deep water wells to drain the landslide, and as dowels to stop

  3. Earthquake induced landslide hazard: a multidisciplinary field observatory in the Marmara SUPERSITE (United States)

    Bigarré, Pascal


    Earthquake-triggered landslides have an increasing disastrous impact in seismic regions due to the fast growing urbanization and infrastructures. Just considering disasters from the last fifteen years, among which the 1999 Chi-Chi earthquake, the 2008 Wenchuan earthquake, and the 2011 Tohoku earthquake, these events generated tens of thousands of coseismic landslides. Those resulted in amazing death toll and considerable damages, affecting the regional landscape including its hydrological main features. Despite a strong impetus in research during past decades, knowledge on those geohazards is still fragmentary, while databases of high quality observational data are lacking. These phenomena call for further collaborative researches aiming eventually to enhance preparedness and crisis management. As one of the three SUPERSITE concept FP7 projects dealing with long term high level monitoring of major natural hazards at the European level, the MARSITE project gathers research groups in a comprehensive monitoring activity developed in the Sea of Marmara Region, one of the most densely populated parts of Europe and rated at high seismic risk level since the 1999 Izmit and Duzce devastating earthquakes. Besides the seismic threat, landslides in Turkey and in this region constitute an important source of loss. The 1999 Earthquake caused extensive landslides while tsunami effects were observed during the post-event surveys in several places along the coasts of the Izmit bay. The 6th Work Package of MARSITE project gathers 9 research groups to study earthquake-induced landslides focusing on two sub-regional areas of high interest. First, the Cekmece-Avcilar peninsula, located westwards of Istanbul, is a highly urbanized concentrated landslide prone area, showing high susceptibility to both rainfalls while affected by very significant seismic site effects. Second, the off-shore entrance of the Izmit Gulf, close to the termination of the surface rupture of the 1999 earthquake

  4. Monitoring landslide dynamics using timeseries of UAV imagery (United States)

    de Jong, S. M.; Van Beek, L. P.


    Landslides are worldwide occurring processes that can have large economic impact and sometimes result in fatalities. Multiple factors are important in landslide processes and can make an area prone to landslide activity. Human factors like drainage and removal of vegetation or land clearing are examples of factors that may cause a landslide. Other environmental factors such as topography and the shear strength of the slope material are more difficult to control. Triggering factors for landslides are typically heavy rainfall events or sometimes by earthquakes or under cutting processes by a river. The collection of data about existing landslides in a given area is important for predicting future landslides in that region. We have setup a monitoring program for landslide using cameras aboard Unmanned Airborne Vehicles. UAV with cameras are able to collect ultra-high resolution images and UAVs can be operated in a very flexible way, they just fit in the back of a car. Here, in this study we used Unmanned Aerial Vehicles to collect a time series of high-resolution images over landslides in France and Australia. The algorithm used to process the UAV images into OrthoMosaics and OrthoDEMs is Structure from Motion (SfM). The process generally results in centimeter precision in the horizontal and vertical direction. Such multi-temporal datasets enable the detection of landslide area, the leading edge slope, temporal patterns and volumetric changes of particular areas of the landslide. We measured and computed surface movement of the landslide using the COSI-Corr image correlation algorithm with ground validation. Our study shows the possibilities of generating accurate Digital Surface Models (DSMs) of landslides using images collected with an Unmanned Aerial Vehicle (UAV). The technique is robust and repeatable such that a substantial time series of datasets can be routinely collected. It is shown that a time-series of UAV images can be used to map landslide movements with

  5. Object-based Landslide Mapping: Examples, Challenges and Opportunities (United States)

    Hölbling, Daniel; Eisank, Clemens; Friedl, Barbara; Chang, Kang-Tsung; Tsai, Tsai-Tsung; Birkefeldt Møller Pedersen, Gro; Betts, Harley; Cigna, Francesca; Chiang, Shou-Hao; Aubrey Robson, Benjamin; Bianchini, Silvia; Füreder, Petra; Albrecht, Florian; Spiekermann, Raphael; Weinke, Elisabeth; Blaschke, Thomas; Phillips, Chris


    Over the last decade, object-based image analysis (OBIA) has been increasingly used for mapping landslides that occur after triggering events such as heavy rainfall. The increasing availability and quality of Earth Observation (EO) data in terms of temporal, spatial and spectral resolution allows for comprehensive mapping of landslides at multiple scales. Most often very high resolution (VHR) or high resolution (HR) optical satellite images are used in combination with a digital elevation model (DEM) and its products such as slope and curvature. Semi-automated object-based mapping makes use of various characteristics of image objects that are derived through segmentation. OBIA enables numerous spectral, spatial, contextual and textural image object properties to be applied during an analysis. This is especially useful when mapping complex natural features such as landslides and constitutes an advantage over pixel-based image analysis. However, several drawbacks in the process of object-based landslide mapping have not been overcome yet. The developed classification routines are often rather complex and limited regarding their transferability across areas and sensors. There is still more research needed to further improve present approaches and to fully exploit the capabilities of OBIA for landslide mapping. In this study several examples of object-based landslide mapping from various geographical regions with different characteristics are presented. Examples from the Austrian and Italian Alps are shown, whereby one challenge lies in the detection of small-scale landslides on steep slopes while preventing the classification of false positives with similar spectral properties (construction areas, utilized land, etc.). Further examples feature landslides mapped in Iceland, where the differentiation of landslides from other landscape-altering processes in a highly dynamic volcanic landscape poses a very distinct challenge, and in Norway, which is exposed to multiple

  6. What rainfall events trigger landslides on the West Coast US? (United States)

    Biasutti, Michela; Seager, Richard; Kirschbaum, Dalia


    A dataset of landslide occurrences compiled by collating google news reports covers 9 full years of data. We show that, while this compilation cannot provide consistent and widespread monitoring everywhere, it is adequate to capture the distribution of events in the major urban areas of the West Coast US and it can be used to provide a quantitative relationship between landslides and rainfall events. The case of the Seattle metropolitan area is presented as an example. The landslide dataset shows a clear seasonality in landslide occurrence, corresponding to the seasonality of rainfall, modified by the accumulation of soil moisture as winter progresses. Interannual variability of landslide occurrences is also linked to interannual variability of monthly rainfall. In most instances, landslides are clustered on consecutive days or at least within the same pentad and correspond to days of large rainfall accumulation at the regional scale. A joint analysis of the landslide data and of the high-resolution PRISM daily rainfall accumulation shows that on days when landslides occurred, the distribution of rainfall was shifted, with rainfall accumulation higher than 10mm/day being more common. Accumulations above 50mm/day much increase the probability of landslides, including the possibility of a major landslide event (one with multiple landslides in a day). The synoptic meteorological conditions associated with these major events show a mid-tropospheric ridge to the south of the target area steering a surface low and bringing enhanced precipitable water towards the Pacific North West. The interaction of the low-level flow with the local orography results in instances of a strong Puget Sound Convergence Zone, with widespread rainfall accumulation above 30mm/day and localized maxima as high as 100mm/day or more.

  7. Landslide Activity Maps Generation by Means of Persistent Scatterer Interferometry

    Directory of Open Access Journals (Sweden)

    Silvia Bianchini


    Full Text Available In this paper a methodology is proposed to elaborate landslide activity maps through the use of PS (Persistent Scatterer data. This is illustrated through the case study of Tramuntana Range in the island of Majorca (Spain, where ALOS (Advanced Land Observing Satellite images have been processed through a Persistent Scatterer Interferometry (PSI technique during the period of 2007–2010. The landslide activity map provides, for every monitored landslide, an assessment of the PS visibility according to the relief, land use, and satellite acquisition parameters. Landslide displacement measurements are projected along the steepest slope, in order to compare landslide velocities with different slope orientations. Additionally, a ground motion activity map is also generated, based on active PS clusters not included within any known landslide phenomenon, but even moving, potentially referred to unmapped landslides or triggered by other kinds of geomorphological processes. In the Tramuntana range, 42 landslides were identified as active, four as being potential to produce moderate damage, intersecting the road Ma-10, which represents the most important road of the island and, thus, the main element at risk. In order to attest the reliability of measured displacements to represent landslide dynamics, a confidence degree evaluation is proposed. In this test site, seven landslides exhibit a high confidence degree, medium for 93 of them, and low for 51. A low confidence degree was also attributed to 615 detected active clusters with a potential to cause moderate damage, as their mechanism of the triggering cause is unknown. From this total amount, 18 of them intersect the Ma-10, representing further potentially hazardous areas. The outcomes of this work reveal the usefulness of landslide activity maps for environmental planning activities, being exportable to other radar data and different geomorphological settings.

  8. Biscayne Bay Alongshore Epifauna (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Field studies to characterize the alongshore epifauna (shrimp, crabs, echinoderms, and small fishes) along the western shore of southern Biscayne Bay were started in...

  9. Bathymetry in Jobos Bay (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 4x4 meter resolution bathymetric surface for Jobos Bay, Puerto Rico (in NAD83 UTM 19 North). The depth values are in meters referenced to the...

  10. Hammond Bay Biological Station (United States)

    Federal Laboratory Consortium — Hammond Bay Biological Station (HBBS), located near Millersburg, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). HBBS was established by...

  11. Humboldt Bay Orthoimages (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of 0.5-meter pixel resolution, four band orthoimages covering the Humboldt Bay area. An orthoimage is remotely sensed image data in which...

  12. Application of a neuro-fuzzy model to landslide-susceptibility mapping for shallow landslides in a tropical hilly area (United States)

    Oh, Hyun-Joo; Pradhan, Biswajeet


    This paper presents landslide-susceptibility mapping using an adaptive neuro-fuzzy inference system (ANFIS) using a geographic information system (GIS) environment. In the first stage, landslide locations from the study area were identified by interpreting aerial photographs and supported by an extensive field survey. In the second stage, landslide-related conditioning factors such as altitude, slope angle, plan curvature, distance to drainage, distance to road, soil texture and stream power index (SPI) were extracted from the topographic and soil maps. Then, landslide-susceptible areas were analyzed by the ANFIS approach and mapped using landslide-conditioning factors. In particular, various membership functions (MFs) were applied for the landslide-susceptibility mapping and their results were compared with the field-verified landslide locations. Additionally, the receiver operating characteristics (ROC) curve for all landslide susceptibility maps were drawn and the areas under curve values were calculated. The ROC curve technique is based on the plotting of model sensitivity — true positive fraction values calculated for different threshold values, versus model specificity — true negative fraction values, on a graph. Landslide test locations that were not used during the ANFIS modeling purpose were used to validate the landslide susceptibility maps. The validation results revealed that the susceptibility maps constructed by the ANFIS predictive models using triangular, trapezoidal, generalized bell and polynomial MFs produced reasonable results (84.39%), which can be used for preliminary land-use planning. Finally, the authors concluded that ANFIS is a very useful and an effective tool in regional landslide susceptibility assessment.

  13. Landslide hazard zonation around Gilgel Gibe-II Hydroelectric ...

    African Journals Online (AJOL)

    The present study was carried out along the newly constructed road from Fofa town to Gilgel Gibe-II powerhouse in South western Ethiopia. In this study, an attempt has been made to provide information on the landslide hazard zones present along the new road. In order to delineate the hazardous zones the landslide ...

  14. Bird Perches Increase Forest Seeds on Puerto Rican Landslides. (United States)

    Aaron B. Shiels; Lawrence R. Walker


    Landslides result in the loss of vertical vegetative structure, soil nutrients, and the soil seed bank. These losses impede timely recovery of tropical forest communities. In this study we added bird perches to six Puerto Rican landslides with three types of surfaces (bare, climbing fern, grass) in an effort to facilitate inputs of forest seeds through bird dispersal...

  15. Application of Video Recognition Technology in Landslide Monitoring System

    Directory of Open Access Journals (Sweden)

    Qingjia Meng


    Full Text Available The video recognition technology is applied to the landslide emergency remote monitoring system. The trajectories of the landslide are identified by this system in this paper. The system of geological disaster monitoring is applied synthetically to realize the analysis of landslide monitoring data and the combination of video recognition technology. Landslide video monitoring system will video image information, time point, network signal strength, power supply through the 4G network transmission to the server. The data is comprehensively analysed though the remote man-machine interface to conduct to achieve the threshold or manual control to determine the front-end video surveillance system. The system is used to identify the target landslide video for intelligent identification. The algorithm is embedded in the intelligent analysis module, and the video frame is identified, detected, analysed, filtered, and morphological treatment. The algorithm based on artificial intelligence and pattern recognition is used to mark the target landslide in the video screen and confirm whether the landslide is normal. The landslide video monitoring system realizes the remote monitoring and control of the mobile side, and provides a quick and easy monitoring technology.

  16. Probabilistic landslide hazards and risk mapping on Penang Island ...

    Indian Academy of Sciences (India)

    This paper deals with landslide hazards and risk analysis of Penang Island, Malaysia using Geo- .... require a priori knowledge of the main causes of landslides .... Soil. Rengam-bukit. 289450. 10.03. 96. 20.73. 2.07 temiang association. Selangor-kangkong. 34197. 1.18. 0. 0.00. 0.00 association. Local alluvium-. 373655.

  17. Characterization of groundwater dynamics in landslides in varved clays

    NARCIS (Netherlands)

    Van der Spek, J.E.; Bogaard, T.A.; Bakker, M.


    Groundwater dynamics may play a significant role in landslides. A detailed model is developed of the groundwater dynamics in landslides in varved clays in the Trièves area in the French Alps. The varved clays consist of a sequence of alternating silt and clay layers, covered by a colluvium layer and

  18. Characterization of groundwater dynamics in landslides in varved clays

    NARCIS (Netherlands)

    Van der Spek, J.E.; Bogaard, T.A.; Bakker, M.


    Groundwater dynamics may play a significant role in landslides. A detailed model is developed of the groundwater dynamics in landslides in varved clays in the Trieves area in the French Alps. The varved clays consist of a sequence of alternating silt and clay layers, covered by a colluvium layer and

  19. Seismically induced landslides: current research by the US Geological Survey. (United States)

    Harp, E.L.; Wilson, R.C.; Keefer, D.K.; Wieczorek, G.F.


    We have produced a regional seismic slope-stability map and a probabilistic prediction of landslide distribution from a postulated earthquake. For liquefaction-induced landslides, in situ measurements of seismically induced pore-water pressures have been used to establish an elastic model of pore pressure generation. -from Authors

  20. Multi-scale landslide risk assessment in Cuba

    NARCIS (Netherlands)

    Castellanos Abella, E.A.


    Landslides cause a considerable amount of damage in the mountainous regions of Cuba, which cover about 25% of the territory. Until now, only a limited amount of research has been carried out in the field of landslide risk assessment in the country. This research presents a methodology and its

  1. Mechanisms of Forest Restoration in Landslide Treatment Areas

    Directory of Open Access Journals (Sweden)

    Yi-Chang Chen


    Full Text Available Reforestation after a landslide facilitates competition between herbaceous plants and arborous plants. Tangible variations in grassland areas in regions susceptible to landslides can only be found within collections of trees. A landslide area in the Sule Watershed was investigated. Relative illuminance results reveal that the Rhodes grass (Chloris gayana Kunth biomass in this landslide area increases with relative illuminance. A comparison of regions with tree islands indicates that the size of the grassland areas decreased and the number of tree islands increased during 2005–2010. Furthermore, a germination experiment in a soil-seed bank indicates that more woody plant species exist around the tree island than in other areas in the landslide region. Trees in a tree island change the micro-climate of the landslide region, and they gather as many nutrients and as much moisture as possible, enabling vegetation to expand around the tree island. Additionally, the area with Rhodes grass and its biomass declined annually in the tree island region. Investigation results show that tree islands and soil-seed banks are suited to reforestation in landslide regions. The pioneering research will assist regional landslide management in Taiwan.

  2. Slope failures in surface mines, methods of studying landslides

    Energy Technology Data Exchange (ETDEWEB)

    Flisiak, J; Korman, S; Mazurek, J


    This paper presents a review of methods of measuring landslide fissures, displacement of ground surface points in the landslide area and of points inside the landslide. An analysis of the landslide process is given, stressing various stages and phases of a landslide. Studies carried out by the Institute of Mining Geomechanics of the Technical University of Mining and Metallurgy in Cracow are evaluated. The studies concentrated on the final state of slopes in brown coal surface mines after a landslide occurs. The necessity of developing an apparatus for continuous recording of displacements of points on a landslide surface is stressed. An apparatus developed by the Institute and used for continuous measuring and recording of displacements is described. The apparatus is used to measure displacements of points during the initial phase of a landslide and during the phase of the largest displacements. The principle of the system consists in locating a number of observation points on the ground and a slope. The points are connected among themselves by flexible connectors. The connectors are equipped with potentiometric transmitters which transform the relative displacements into electric pulses. These pulses are recorded by a conventional recording apparatus. (55 refs.) (In Polish)

  3. Clayey landslide initiation and acceleration strongly modulated by soil swelling (United States)

    Schulz, William; Smith, Joel B.; Wang, Gonghui; Jiang, Yao; Roering, Joshua J.


    Largely unknown mechanisms restrain motion of clay-rich, slow-moving landslides that are widespread worldwide and rarely accelerate catastrophically. We studied a clayey, slow-moving landslide typical of thousands in northern California, USA, to decipher hydrologic-mechanical interactions that modulate landslide dynamics. Similar to some other studies, observed pore-water pressures correlated poorly with landslide reactivation and speed. In situ and laboratory measurements strongly suggested that variable pressure along the landslide's lateral shear boundaries resulting from seasonal soil expansion and contraction modulated its reactivation and speed. Slope-stability modeling suggested that the landslide's observed behavior could be predicted by including transient swell pressure as a resistance term, whereas modeling considering only transient hydrologic conditions predicted movement 5–6 months prior to when it was observed. All clayey soils swell to some degree; hence, our findings suggest that swell pressure likely modulates motion of many landslides and should be considered to improve forecasts of clayey landslide initiation and mobility.

  4. Landslide Hazard Mapping in Rwanda Using Logistic Regression (United States)

    Piller, A.; Anderson, E.; Ballard, H.


    Landslides in the United States cause more than $1 billion in damages and 50 deaths per year (USGS 2014). Globally, figures are much more grave, yet monitoring, mapping and forecasting of these hazards are less than adequate. Seventy-five percent of the population of Rwanda earns a living from farming, mostly subsistence. Loss of farmland, housing, or life, to landslides is a very real hazard. Landslides in Rwanda have an impact at the economic, social, and environmental level. In a developing nation that faces challenges in tracking, cataloging, and predicting the numerous landslides that occur each year, satellite imagery and spatial analysis allow for remote study. We have focused on the development of a landslide inventory and a statistical methodology for assessing landslide hazards. Using logistic regression on approximately 30 test variables (i.e. slope, soil type, land cover, etc.) and a sample of over 200 landslides, we determine which variables are statistically most relevant to landslide occurrence in Rwanda. A preliminary predictive hazard map for Rwanda has been produced, using the variables selected from the logistic regression analysis.

  5. Landslides Zonation Hazard: relation between geological structures and landslides occurrence in hilly tropical regions of Brazil. (United States)

    Cerri, Rodrigo I; Reis, Fábio A G V; Gramani, Marcelo F; Giordano, Lucilia C; Zaine, José Eduardo


    This paper presents a new approach of landslides zonation hazard studies, based on an integrated study of structural data along with geomorphological and external factors, in a hilly regions of Brazil, covered by a tropical humid rain-forest, called Serra do Mar. The Serra do Mar consists of a hilly region along the east coast of Brazil, with high slopes and many geological structures in a gneiss - migmatitic terrain. In contrast to traditional approaches, this method proposes that structural data (foliation, fractures and bedding planes) and its relation with the slope geometry, is important to be consider in the landslide zonation hazard, along with declivity, relative relief, soil and rock properties, land use and vegetation cover and hydrogeological and climate factors. Results show that slopes with high hazard have the same dip direction of geological structures. Landslide zonation hazard using structural data contributes to a better understanding of how these structures, preserved in tropical residual soils, influence on slope stability and generates landslides.

  6. Landslides Zonation Hazard: relation between geological structures and landslides occurrence in hilly tropical regions of Brazil

    Directory of Open Access Journals (Sweden)



    Full Text Available ABSTRACT This paper presents a new approach of landslides zonation hazard studies, based on an integrated study of structural data along with geomorphological and external factors, in a hilly regions of Brazil, covered by a tropical humid rain-forest, called Serra do Mar. The Serra do Mar consists of a hilly region along the east coast of Brazil, with high slopes and many geological structures in a gneiss - migmatitic terrain. In contrast to traditional approaches, this method proposes that structural data (foliation, fractures and bedding planes and its relation with the slope geometry, is important to be consider in the landslide zonation hazard, along with declivity, relative relief, soil and rock properties, land use and vegetation cover and hydrogeological and climate factors. Results show that slopes with high hazard have the same dip direction of geological structures. Landslide zonation hazard using structural data contributes to a better understanding of how these structures, preserved in tropical residual soils, influence on slope stability and generates landslides.

  7. Object-based Classification for Detecting Landslides and Stochastic Procedure to landslide susceptibility maps - A Case at Baolai Village, SW Taiwan (United States)

    Lin, Ying-Tong; Chang, Kuo-Chen; Yang, Ci-Jian


    As the result of global warming in the past decades, Taiwan has experienced more and more extreme typhoons with hazardous massive landslides. In this study, we use object-oriented analysis method to classify landslide area at Baolai village by using Formosat-2 satellite images. We used for multiresolution segmented to generate the blocks, and used hierarchical logic to classified 5 different kinds of features. After that, classification the landslide into different type of landslide. Beside, we use stochastic procedure to integrate landslide susceptibility maps. This study assumed that in the extreme event, 2009 Typhoon Morakot, which precipitation goes to 1991.5mm in 5 days, and the highest landslide susceptible area. The results show that study area's landslide area was greatly changes, most of landslide was erosion by gully and made dip slope slide, or erosion by the stream, especially at undercut bank. From the landslide susceptibility maps, we know that the old landslide area have high potential to occur landslides in the extreme event. This study demonstrates the changing of landslide area and the landslide susceptible area. Keywords: Formosat-2, object-oriented, segmentation, classification, landslide, Baolai Village, SW Taiwan, FS

  8. Citizen science, GIS, and the global hunt for landslides (United States)

    Juang, C.; Stanley, T.; Kirschbaum, D.


    Landslides occur across the United States and around the world, causing much suffering and infrastructure damage. Many of these events have been recorded in the Global Landslide Catalog (GLC), a worldwide record of recently rainfall-triggered landslides. The extent and composition of this database has been affected by the limits of media search tools and available staffing. Citizen scientists could expand the effort exponentially, as well as diversify the knowledge base of the research team. In order to enable this collaboration the NASA Center for Climate Simulation has created a GIS portal for viewing, editing, and managing the GLC. The data is also exposed through a Rest API, for easy incorporation into geospatial websites by third parties. Future developments may include the ability to store polygons delineating large landslides, digitization from recent satellite imagery, and the establishment of a community for international landslide research that is open to both lay and academic users.

  9. The influence of preferential flow on pressure propagation and landslide triggering of the Rocca Pitigliana landslide (United States)

    Shao, Wei; Bogaard, Thom; Bakker, Mark; Berti, Matteo


    The fast pore water pressure response to rain events is an important triggering factor for slope instability. The fast pressure response may be caused by preferential flow that bypasses the soil matrix. Currently, most of the hydro-mechanical models simulate pore water pressure using a single-permeability model, which cannot quantify the effects of preferential flow on pressure propagation and landslide triggering. Previous studies showed that a model based on the linear-diffusion equation can simulate the fast pressure propagation in near-saturated landslides such as the Rocca Pitigliana landslide. In such a model, the diffusion coefficient depends on the degree of saturation, which makes it difficult to use the model for predictions. In this study, the influence of preferential flow on pressure propagation and slope stability is investigated with a 1D dual-permeability model coupled with an infinite-slope stability approach. The dual-permeability model uses two modified Darcy-Richards equations to simultaneously simulate the matrix flow and preferential flow in hillslopes. The simulated pressure head is used in an infinite-slope stability analysis to identify the influence of preferential flow on the fast pressure response and landslide triggering. The dual-permeability model simulates the height and arrival of the pressure peak reasonably well. Performance of the dual-permeability model is as good as or better than the linear-diffusion model even though the dual-permeability model is calibrated for two single pulse rain events only, while the linear-diffusion model is calibrated for each rain event separately. In conclusion, the 1D dual-permeability model is a promising tool for landslides under similar conditions.

  10. Soil and biomass carbon re-accumulation after landslide disturbances (United States)

    Schomakers, Jasmin; Jien, Shih-Hao; Lee, Tsung-Yu; Huang-Chuan, Jr.; Hseu, Zeng-Yei; Lin, Zan Liang; Lee, Li-Chin; Hein, Thomas; Mentler, Axel; Zehetner, Franz


    In high-standing islands of the Western Pacific, typhoon-triggered landslides occasionally strip parts of the landscape of its vegetative cover and soil layer and export large amounts of biomass and soil organic carbon (OC) from land to the ocean. After such disturbances, new vegetation colonizes the landslide scars and OC starts to re-accumulate. In the subtropical mountains of Taiwan and in other parts of the world, bamboo (Bambusoideae) species may invade at a certain point in the succession of recovering landslide scars. Bamboo has a high potential for carbon sequestration because of its fast growth and dense rooting system. However, it is still largely unknown how these properties translate into soil OC re-accumulation rates after landslide disturbance. In this study, a chronosequence was established on four former landslide scars in the Central Mountain Range of Taiwan, ranging in age from 6 to 41 years post disturbance as determined by landslide mapping from remote sensing. The younger landslide scars were colonized by Miscanthus floridulus, while after approx. 15 to 20 years of succession, bamboo species (Phyllostachys) were dominating. Biomass and soil OC stocks were measured on the recovering landslide scars and compared to an undisturbed Cryptomeria japonica forest stand in the area. After initially slow re-vegetation, biomass carbon accumulated in Miscanthus stands with mean annual accretion rates of 2 ± 0.5 Mg C ha- 1 yr- 1. Biomass carbon continued to increase after bamboo invasion and reached 40% of that in the reference forest site after 41 years of landslide recovery. Soil OC accumulation rates were 2.0 Mg C ha- 1 yr- 1, 6 to 41 years post disturbance reaching 64% of the level in the reference forest. Our results from this in-situ study suggest that recovering landslide scars are strong carbon sinks once an initial lag period of vegetation re-establishment is overcome.

  11. Microstructures in landslides in northwest China - Implications for creeping displacements? (United States)

    Schäbitz, M.; Janssen, C.; Wenk, H.-R.; Wirth, R.; Schuck, B.; Wetzel, H.-U.; Meng, X.; Dresen, G.


    Microstructures, mineralogical composition and texture of selected landslide samples from three landslides in the southern part of the Gansu Province (China) were examined with optical microscopy, transmission electron microscopy (TEM), x-ray diffraction (XRD) and synchrotron x-ray diffraction measurements. Common sheet silicates are chlorite, illite, muscovite, kaolinite, pyrophyllite and dickite. Other minerals are quartz, calcite, dolomite and albite. In one sample, graphite and amorphous carbon were detected by TEM-EDX analyses and TEM high-angle annular dark-field images. The occurrence of graphite and pyrophyllite with very low friction coefficients in the gouge material of the Suoertou and Xieliupo landslides is particularly significant for reducing the frictional strength of the landslides. It is proposed that the landslides underwent comparable deformation processes as fault zones. The low friction coefficients provide strong evidence that slow-moving landsliding is controlled by the presence of weak minerals. In addition, TEM observations document that grain size reduction in clayey slip zone material was produced mainly by mechanical abrasion. For calcite and quartz, grain size reduction was attributed to both pressure solution and cataclasis. Therefore, besides landslide composition, the occurrence of ultrafine-grained slip zone material may also contribute to weakening processes of landslides. TEM images of slip-zone samples show both locally aligned clay particles, as well as kinked and folded sheet silicates, which are widely disseminated in the whole matrix. Small, newly formed clay particles have random orientations. Based on synchrotron x-ray diffraction measurements, the degree of preferred orientation of constituent sheet silicates in local shear zones of the Suoertou and Duang-He-Ba landslide is strong. This work is the first reported observation of well-oriented clay fabrics in landslides.

  12. Solid discharge and landslide activity at basin scale (United States)

    Ardizzone, F.; Guzzetti, F.; Iadanza, C.; Rossi, M.; Spizzichino, D.; Trigila, A.


    This work presents a preliminary analysis aimed at understanding the relationship between landslide sediment supply and sediment yield at basin scale in central and southern Italy. A database of solid discharge measurements regarding 116 gauging stations, located along the Apennines chain in Italy, has been compiled by investigating the catalogues, named Annali Idrologici, published by Servizio Idrografico e Mareografico Italiano in the period from 1917 to 1997. The database records several information about the 116 gauging stations, and especially reports the sediment yield monthly measurements (103 ton) and the catchments area (km2). These data have been used to calculate the average solid yield and the normalized solid yield for each station in the observation period. The Italian Landslide Inventory (Progetto IFFI) has been used to obtained the size of the landslides, in order to estimate the landslide mobilization rates. The IFFI Project funded by the Italian Government is realized by ISPRA (Italian National Institute for Environmental Protection and Research - Geological Survey of Italy) in partnership with the 21 Regions and Self Governing Provinces. 21 of the 116 gauging stations and the related catchments have been selected on the basis of the length of the solid discharge observation period and excluding the catchments with dams located upstream the stations. The landslides inside the selected catchments have been extracted from the IFFI inventory, calculating the planimetric area of each landslide. Considering both the shallow and deep landslides, the landslide volume has been estimated using an empirical power law relation (landslide area vs. volume). The total landslide volume in the study areas and the average sediment yield measured at the gauging stations have been compared, analysing the behaviour of the basins which drainage towards the Tyrrhenian sea and the basins which drainage towards the Adriatic sea.

  13. Investigation of landslide potential parameters on Zonguldak-Ereğli Highway and adverse effects of landslides in the region. (United States)

    Can, Eray


    Landslides are natural phenomena in the same class of natural disasters as earthquakes, floods, hurricanes, erosion, and volcanic eruptions that adversely affect human lives and property. Owing to their widespread occurrence, landslides are easily visible and able to be partially understood by people witnessing them. Nevertheless, to comprehend the detail of their formation and determine their potential, it is necessary to undertake geodetic, geological, and geophysical measurements in regions prone to landslides. By analyzing these measurements, it is possible to better ascertain those regions predisposed to landslides and thus provide the means to prevent loss of life and property. The city of Zonguldak, situated in the Western Black Sea region of Turkey, has a high occurrence of landslides owing to its harsh topography with rugged and steep slopes and rainfall in almost every season. Furthermore, the diurnal temperature ranging up to 10 °C in all seasons, especially in winter, plays a crucial role in rock disintegration in this region. Other factors damage ground composition and trigger landslides, such as underground mining operations, road construction that collapses rocky hills using explosives, and excavation works in steep terrain for building construction. This study gives a detailed account of the causes and adverse effects of landslides and their parameters through examples of landslide occurrences in the region, together with the results and analyses of two periods of geodetic measurements conducted on the Zonguldak-Ereğli Highway in Ilıksu district.

  14. Technical Note: Assessing predictive capacity and conditional independence of landslide predisposing factors for shallow landslide susceptibility models

    Directory of Open Access Journals (Sweden)

    S. Pereira


    Full Text Available The aim of this study is to identify the landslide predisposing factors' combination using a bivariate statistical model that best predicts landslide susceptibility. The best model is one that has simultaneously good performance in terms of suitability and predictive power and has been developed using variables that are conditionally independent. The study area is the Santa Marta de Penaguião council (70 km2 located in the Northern Portugal.

    In order to identify the best combination of landslide predisposing factors, all possible combinations using up to seven predisposing factors were performed, which resulted in 120 predictions that were assessed with a landside inventory containing 767 shallow translational slides. The best landslide susceptibility model was selected according to the model degree of fitness and on the basis of a conditional independence criterion. The best model was developed with only three landslide predisposing factors (slope angle, inverse wetness index, and land use and was compared with a model developed using all seven landslide predisposing factors.

    Results showed that it is possible to produce a reliable landslide susceptibility model using fewer landslide predisposing factors, which contributes towards higher conditional independence.

  15. The preparation of landslide map by Landslide Numerical Risk Factor (LNRF model and Geographic Information System (GIS

    Directory of Open Access Journals (Sweden)

    Ali Mohammadi Torkashvand


    Full Text Available One of the risks to threaten mountainous areas is that hillslope instability caused damage to lands. One of the most dangerous instabilities is mass movement and much movement occurs due to slip. The aim of this study is zonation of landslide hazards in a basin of the Ardebil province, the eastern slopes of Sabalan, Iran. Geological and geomorphologic conditions, climate and type of land use have caused susceptibility of this watershed to landslides. Firstly, maps of the main factors affecting landslide occurrence including slope, distance from faults, lithology, elevation and precipitation were prepared and digitized. Then, by using interpretation of aerial photos and satellite images and field views, the ground truth map of landslides was prepared. Each basic layer (factor and landslide map were integrated to compute the numeric value of each factor with the help of a Landslide Numerical Risk Factor (LNRF model and landslide occurrence percent obtained in different units from each of the maps. Finally, with overlapping different data layers, a landslide hazard zonation map was prepared. Results showed that 67.85% of the basin has high instability, 7.76% moderate instability and 24.39% low instability.

  16. Presentation and Analysis of a Worldwide Database of Earthquake-Induced Landslide Inventories : Earthquake-Induced Landslide Inventories

    NARCIS (Netherlands)

    Tanyas, Hakan; Van Westen, Cees J.; Allstadt, Kate E.; Anna Nowicki Jessee, M.; Görüm, Tolga; Jibson, Randall W.; Godt, Jonathan W.; Sato, Hiroshi P.; Schmitt, Robert G.; Marc, Odin; Hovius, Niels


    Earthquake‐induced landslide (EQIL) inventories are essential tools to extend our knowledge of the relationship between earthquakes and the landslides they can trigger. Regrettably, such inventories are difficult to generate and therefore scarce, and the available ones differ in terms of their

  17. Global Landslides on Rapidly Spinning Spheroids (United States)

    Scheeres, Daniel J.; Sanchez, P.


    The angle of repose and conditions for global landslides on the surfaces of small, rapidly spinning, spheroidal asteroids are studied. Applying techniques of soil mechanics, we develop a theory for, and examples of, how regolith will fail and flow in this microgravity environment. Our motivation is to develop an understanding of the "top-shaped" class of asteroids based on analytical soil mechanics. Our analysis transforms the entire asteroid surface into a local frame where we can model it as a conventional granular pile with a surface slope, acceleration and height variations as a function of the body's spin rate, shape and density. A general finding is that the lowest point on a rapidly spinning spheroid is at the equator with the effective height of surface material monotonically increasing towards the polar regions, where the height can be larger than the physical radius of the body. We study the failure conditions of both cohesionless and cohesive regolith, and develop specific predictions of the surface profile as a function of the regolith angle of friction and the maximum spin rate experienced by the body. The theory also provides simple guidelines on what the shape may look like, although we do not analyze gravitationally self-consistent evolution of the body shape. The theory is tested with soft-sphere discrete element method granular mechanics simulations to better understand the dynamical aspects of global asteroid landslides. We find significant differences between failure conditions for cohesive and cohesionless regolith. In the case of cohesive regolith, we show that extremely small values of strength (much less than that found in lunar regolith) can stabilize a surface even at very rapid spin rates. Cohesionless surfaces, as expected, fail whenever their surface slopes exceed the angle of friction. Based on our analysis we propose that global landslides and the flow of material towards the equator on spheroidal bodies are precipitated by exogenous

  18. The effect of terrain factors on landslide features along forest road ...

    African Journals Online (AJOL)

    Results indicate that the landslide area at a distance of 80 to 100 m from road edge was significantly more than that of other distances. The landslide dimensions increased with increasing slope angle. The mean of landslide area and mean of landslide volume on the Northwest aspect was significantly more than that on ...

  19. An integrated methodology to develop a standard for landslide early warning systems


    Fathani, Teuku Faisal; Karnawati, Dwikorita; Wilopo, Wahyu


    Landslides are one of the most widespread and commonly occurring natural hazards. In regions of high vulnerability, these complex hazards can cause significant negative social and economic impacts. Considering the worldwide susceptibility to landslides, it is necessary to establish a standard for early warning systems specific to landslide disaster risk reduction. This standard would provide guidance in conducting landslide detection, prediction, interpretation, and response...

  20. Design of Simple Landslide Monitoring System (United States)

    Meng, Qingjia; Cai, Lingling


    The simple landslide monitoring system is mainly designed for slope, collapse body and surface crack. In the harsh environment, the dynamic displacement data of the disaster body is transmitted to the terminal acquisition system in real time. The main body of the system adopt is PIC32MX795F512. This chip is to realize low power design, wakes the system up through the clock chip, and turns on the switching power supply at set time, which makes the wireless transmission module running during the interval to ensure the maximum battery consumption, so that the system can be stable long term work.

  1. Slopeland utilizable limitation classification using landslide inventory (United States)

    Tsai, Shu Fen; Lin, Chao Yuan


    In 1976, "Slopeland Conservation and Utilization Act" was promulgated as well as the criteria for slopeland utilization limitation classification (SULC) i.e., average slope, effective soil depth, degree of soil erosion, and parent rock became standardized. Due to the development areas on slope land steadily increased and the extreme rainfall events occurred frequently, the areas affected by landslides also increased year by year. According to the act, the land which damaged by disaster must be categorized to the conservation land and required rehabilitation. Nevertheless, the large-scale disaster on slope land and the limitation of SWCB officers are the constraint of field investigation. Therefore, how to establish the ongoing inspective procedure of post-disaster SULC using remote sensing was essential. A-Li-Shan, Ai-Liao, and Tai-Ma-Li Watershed were selected to be case studies in this project. The spatial data from big data i.e., Digital Elevation Model (DEM), soil map, and satellite images integrated with Geographic Information Systems (GIS) were applied to post-disaster SULC. The collapse and deposition area which delineated by vegetation recovery rate was established landslide inventory of cadastral unit combined with watershed unit. The results were verified with field survey and the accuracy was 97%. The landslide inventory could be an effective reference for sediment disaster investigation and a practical evidence for judgement to expropriation. Finally, the results showed that the ongoing inspective procedure of post-disaster SULC was practicable. From the four criteria, the average slope was the major factor. It was found that the non-uniform slopes, especially derived from cadastral units, often produce significant slope difference and lead to errors of average slope evaluation. Therefore, the Grid-based DEM slope derivation has been recommended as the standard method to calculate the average slope. Others criteria were previously required to classify

  2. 75 FR 11837 - Chesapeake Bay Watershed Initiative (United States)


    ... DEPARTMENT OF AGRICULTURE Commodity Credit Corporation Chesapeake Bay Watershed Initiative AGENCY...: Notice of availability of program funds for the Chesapeake Bay Watershed Initiative. SUMMARY: The... through the Chesapeake Bay Watershed Initiative for agricultural producers in the Chesapeake Bay watershed...

  3. 33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. (United States)


    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York...

  4. Landslides Mapped from LIDAR Imagery, Kitsap County, Washington (United States)

    McKenna, Jonathan P.; Lidke, David J.; Coe, Jeffrey A.


    Landslides are a recurring problem on hillslopes throughout the Puget Lowland, Washington, but can be difficult to identify in the densely forested terrain. However, digital terrain models of the bare-earth surface derived from LIght Detection And Ranging (LIDAR) data express topographic details sufficiently well to identify landslides. Landslides and escarpments were mapped using LIDAR imagery and field checked (when permissible and accessible) throughout Kitsap County. We relied almost entirely on derivatives of LIDAR data for our mapping, including topographic-contour, slope, and hill-shaded relief maps. Each mapped landslide was assigned a level of 'high' or 'moderate' confidence based on the LIDAR characteristics and on field observations. A total of 231 landslides were identified representing 0.8 percent of the land area of Kitsap County. Shallow debris topples along the coastal bluffs and large (>10,000 m2) landslide complexes are the most common types of landslides. The smallest deposit mapped covers an area of 252 m2, while the largest covers 0.5 km2. Previous mapping efforts that relied solely on field and photogrammetric methods identified only 57 percent of the landslides mapped by LIDAR (61 percent high confidence and 39 percent moderate confidence), although nine landslides previously identified were not mapped during this study. The remaining 43 percent identified using LIDAR have 13 percent high confidence and 87 percent moderate confidence. Coastal areas are especially susceptible to landsliding; 67 percent of the landslide area that we mapped lies within 500 meters of the present coastline. The remaining 33 percent are located along drainages farther inland. The LIDAR data we used for mapping have some limitations including (1) rounding of the interface area between low slope surfaces and vertical faces (that is, along the edges of steep escarpments) which results in scarps being mapped too far headward (one or two meters), (2) incorrect laser

  5. On the occurrence of fatal landslides in 2008 (United States)

    Petley, D.


    This paper represents the latest in an annual review of fatal landslide events worldwide, based upon the Durham Fatal Landslide Database. Landslide events were inevitably dominated by the occurrence of the 12th May Wenchuan Earthquake in Sichuan Province of China, which triggered very extensive landsliding. Whilst it will be very difficult to estimate the true impact of this event in terms of landslides, the Chinese authorities estimate that about 29,000 people were killed by landslides, with several thousand more losing their lives whilst trapped in rubble due to the inability of rescuers to pass through landslide affected areas. Considerable work is needed to understand the reasons for the intensity of the landslide processes. Elsewhere the number of fatal landslides recorded totalled 405 worldwide. These caused 3526 fatalities, giving a total for the year of about 32,526 people. To put this into context, according to the CRED EM-DAT database the recorded number of fatalities from volcanic eruptions in the period 2000 to 2008 inclusive is 221! The distribution of fatal landslides followed the familiar patterns observed in previous years, with distinct clusters in Central China, along the southern edge of the Himalayas, in the Caribbean, in Central America, western S. America, along the western edge of the Philippine Sea plate and in Indonesia, plus a scattering elsewhere. The temporal distribution shows strong seasonality, with the peak occurring during the northern hemisphere summer. Unusually however, the peak month was September (usually it is in July), and there were large numbers of landslide events right through to November. The November landslide clusters occurred in SE. Asia and in Central / S. America, reflecting very heavy rains in these regions at that time. The reasons for this are not clear at present, although may be linked to weakening La Nina conditions that have prevailed through much of the year. An analysis is made of the relationship between

  6. Landslide susceptibility mapping using a neuro-fuzzy (United States)

    Lee, S.; Choi, J.; Oh, H.


    This paper develops and applied an adaptive neuro-fuzzy inference system (ANFIS) based on a geographic information system (GIS) environment using landslide-related factors and location for landslide susceptibility mapping. A neuro-fuzzy system is based on a fuzzy system that is trained by a learning algorithm derived from the neural network theory. The learning procedure operates on local information, and causes only local modifications in the underlying fuzzy system. The study area, Boun, suffered much damage following heavy rain in 1998 and was selected as a suitable site for the evaluation of the frequency and distribution of landslides. Boun is located in the central part of Korea. Landslide-related factors such as slope, soil texture, wood type, lithology, and density of lineament were extracted from topographic, soil, forest, and lineament maps. Landslide locations were identified from interpretation of aerial photographs and field surveys. Landslide-susceptible areas were analyzed by the ANFIS method and mapped using occurrence factors. In particular, we applied various membership functions (MFs) and analysis results were verified using the landslide location data. The predictive maps using triangular, trapezoidal, and polynomial MFs were the best individual MFs for modeling landslide susceptibility maps (84.96% accuracy), proving that ANFIS could be very effective in modeling landslide susceptibility mapping. Various MFs were used in this study, and after verification, the difference in accuracy according to the MFs was small, between 84.81% and 84.96%. The difference was just 0.15% and therefore the choice of MFs was not important in the study. Also, compared with the likelihood ratio model, which showed 84.94%, the accuracy was similar. Thus, the ANFIS could be applied to other study areas with different data and other study methods such as cross-validation. The developed ANFIS learns the if-then rules between landslide-related factors and landslide

  7. Surveying perceptions of landslide risk management in Norway (United States)

    Chiu, Jessica Ka Yi; Eidsvig, Unni


    Enhanced precipitation due to climate change leads to increase in both frequency and intensity of landslides in Norway. A proactive approach to risk management is therefore required to significantly reduce the losses associated with landslides. Opinions and perceptions from practitioners on the performance of landslide risk management can provide insights on areas for improvement in the landslide risk management strategies in Norway. The Risk Management Index (RMI), proposed by Cardona et al. (2004), is a well-established method to measure perceptions of disaster management of selected actors holistically. The RMI is measured based on opinion questionnaires to technical staff, decision-makers, and stakeholders involved in all stages of risk reduction strategies. It is a composite index that considers a wide variety of strategies to manage risks, including structural and non-structural measures, acceptance strategies, disaster management, and risk transfer. The RMI method was modified to be implemented in landslide hazards and to fit with Norwegian conditions. An opinion survey was conducted in autumn 2015 to measure perceptions of landslide risk management in Norway. Perceptions were surveyed for two time periods: 2015 and 2050, and are based on national, county, and municipality levels. Based on the survey results, performance of landslide risk management at any administrative levels in Norway is perceived to improve from `significant' in 2015 to `significant' to `outstanding' in 2050. Knowledge and technology, climate, risk perceptions, and anthropogenic activities are mostly considered by respondents for their 2050 perceptions. Several aspects of landslide risk management in Norway can be improved. For example, landslide hazard evaluation and mapping should be prioritised in Norway. Upgrading, retrofitting, and reconstruction of assets may also be included in the landslide risk reduction strategies. In addition, there should be more focus on inter

  8. The double landslide-induced tsunami (United States)

    Tinti, S.; Armigliat, A.; Manucci, A.; Pagnoni, G.; Tonini, R.; Zaniboni, F.; Maramai, A.; Graziani, L.

    The 2002 crisis of Stromboli culminated on December 30 in a series of mass failures detached from the Sciara del Fuoco, with two main landslides, one submarine followed about 7 min later by a second subaerial. These landslides caused two distinct tsunamis that were seen by most people in the island as a unique event. The double tsunami was strongly damaging, destroying several houses in the waterfront at Ficogrande, Punta Lena, and Scari localities in the northeastern coast of Stromboli. The waves affected also Panarea and were observed in the northern Sicily coast and even in Campania, but with minor effects. There are no direct instrumental records of these tsunamis. What we know resides on (1) observations and quantification of the impact of the waves on the coast, collected in a number of postevent field surveys; (2) interviews of eyewitnesses and a collection of tsunami images (photos and videos) taken by observers; and (3) on results of numerical simulations. In this paper, we propose a critical reconstruction of the events where all the available pieces of information are recomposed to form a coherent and consistent mosaic.

  9. Landslides along Highways: GIS-based Inventory and Planning Issues (United States)

    Jaeger, Ann-Kathrin; Klose, Martin; Damm, Bodo


    Highways rank as critical transportation infrastructures that are at risk of landslides in many areas worldwide (e.g., Hungr et al., 1999; Bhandary et al., 2013). Safe and affordable operations of traffic routes constitute the two main criteria for transportation planning in landslide-prone terrain. A right balancing of these often conflicting priorities requires profound knowledge of landslide locations across highway networks and the costs caused by landslides in the past (e.g., Saha et al., 2005). Much of the direct costs affecting transportation departments relate to capital investments for landslide repair or mitigation and operational expenditures in connection with maintenance works. A systematic collection and inventory of such data sets combined with an acquisition of hazard information on vulnerable road sections is still rarely the case in engineering practice. This is despite significant cost impacts and budgetary burdens, especially in peripheral mountain areas where financial resources are naturally limited (e.g., Klose et al., 2014). The present contribution introduces a regional inventory of landslides along highways in the Harz Mountains, NW Germany. As subset of a landslide database for the entire country, this focused GIS-based inventory has been compiled in close collaboration with the Lower Saxony Department of Transportation. The inventory includes data sets gathered by archive studies and relies on high-quality information sources such as maintenance protocols, geotechnical reports, and documents from tendering, controlling, and accounting. A mapping tool in ArcGIS format is used to specify and visualize road sections affected by landslides. This spatial information on hazard exposure is complemented by narrative risk profiles for landslide sites showing a long history of damage events. By summarizing the occurrence dates of landslides, the associated damages, and the types and costs of repair or prevention, such risk profiles are useful to

  10. Modelling the Probability of Landslides Impacting Road Networks (United States)

    Taylor, F. E.; Malamud, B. D.


    During a landslide triggering event, the threat of landslides blocking roads poses a risk to logistics, rescue efforts and communities dependant on those road networks. Here we present preliminary results of a stochastic model we have developed to evaluate the probability of landslides intersecting a simple road network during a landslide triggering event and apply simple network indices to measure the state of the road network in the affected region. A 4000 x 4000 cell array with a 5 m x 5 m resolution was used, with a pre-defined simple road network laid onto it, and landslides 'randomly' dropped onto it. Landslide areas (AL) were randomly selected from a three-parameter inverse gamma probability density function, consisting of a power-law decay of about -2.4 for medium and large values of AL and an exponential rollover for small values of AL; the rollover (maximum probability) occurs at about AL = 400 m2 This statistical distribution was chosen based on three substantially complete triggered landslide inventories recorded in existing literature. The number of landslide areas (NL) selected for each triggered event iteration was chosen to have an average density of 1 landslide km-2, i.e. NL = 400 landslide areas chosen randomly for each iteration, and was based on several existing triggered landslide event inventories. A simple road network was chosen, in a 'T' shape configuration, with one road 1 x 4000 cells (5 m x 20 km) in a 'T' formation with another road 1 x 2000 cells (5 m x 10 km). The landslide areas were then randomly 'dropped' over the road array and indices such as the location, size (ABL) and number of road blockages (NBL) recorded. This process was performed 500 times (iterations) in a Monte-Carlo type simulation. Initial results show that for a landslide triggering event with 400 landslides over a 400 km2 region, the number of road blocks per iteration, NBL,ranges from 0 to 7. The average blockage area for the 500 iterations (A¯ BL) is about 3000 m

  11. Hydroclimatic conditions preceding the March 2014 Oso landslide (United States)

    Henn, Brian; Cao, Qian; Lettenmaier, Dennis P.; Magirl, Christopher S.; Mass, Clifford; Bower, J. Brent; St. Laurent, Michael; Mao, Yixin; Perica, Sanja


    The 22 March 2014 Oso landslide was one of the deadliest in U.S. history, resulting in 43 fatalities and the destruction of more than 40 structures. We examine synoptic conditions, precipitation records and soil moisture reconstructions in the days, months, and years preceding the landslide. Atmospheric reanalysis shows a period of enhanced moisture transport to the Pacific Northwest beginning on 11 February 2014. The 21- to 42-day periods prior to the landslide had anomalously high precipitation; we estimate that 300-400 mm of precipitation fell at Oso in the 21 days prior to the landslide. Relative only to historical periods ending on 22 March, the return periods of these precipitation accumulations are large (25-88 years). However, relative to the largest accumulations from any time of the year (annual maxima), return periods are more modest (2-6 years). In addition to the 21-42 days prior to the landslide, there is a secondary maximum in the precipitation return periods for the 4 years preceding the landslide. Reconstructed soil moisture was anomalously high prior to the landslide, with a return period that exceeded 40 years about a week before the event.

  12. Landslide Hazard-Prevention in Balakot Region, Pakistan

    International Nuclear Information System (INIS)

    Soomro, A.S.


    The earthquake triggered enormous landslides on October 8, 2005 in the various areas of Pakistan especially in Balakot Region. This research paper fulfilled the urge to develop alternative landslide planning based on the consideration of landslide preventing measures using GIS (Geographical Information Systems) techniques. This specific type of land use planning differs from traditional type of land use planning due to consideration of the probable hazard of landslide disaster by applying zonation methodology for finding the appropriate suitable areas for various development purposes. The various parameters e.g. elevation, slope angle, forest/ vegetations, faults, landslide zones, and rainfall were utilized as GIS data themes in the vector format. The different GIS techniques were used: (i) Clipping the data layers; (II) Spatial analysis by converting the vector layers into raster format; (III) Classification of data themes into certain classes; (IV) Overlaying the data themes and (v) Map calculation techniques through GIS standard software. This applied research has found that various different regions such as high suitable, moderate suitable, low suitable and unsuitable may be considered as preventive measures from the probable hazard of the landslide disaster in future for rehabilitation and redevelopment purpose which can save human lives, residential and commercial infrastructure in future. It is believed that the various predicted regions for preventing landslide hazards can be very beneficial to the decision makers for the redevelopment of the region in future. (author)

  13. Toward a comprehensive areal model of earthquake-induced landslides (United States)

    Miles, S.B.; Keefer, D.K.


    This paper provides a review of regional-scale modeling of earthquake-induced landslide hazard with respect to the needs for disaster risk reduction and sustainable development. Based on this review, it sets out important research themes and suggests computing with words (CW), a methodology that includes fuzzy logic systems, as a fruitful modeling methodology for addressing many of these research themes. A range of research, reviewed here, has been conducted applying CW to various aspects of earthquake-induced landslide hazard zonation, but none facilitate comprehensive modeling of all types of earthquake-induced landslides. A new comprehensive areal model of earthquake-induced landslides (CAMEL) is introduced here that was developed using fuzzy logic systems. CAMEL provides an integrated framework for modeling all types of earthquake-induced landslides using geographic information systems. CAMEL is designed to facilitate quantitative and qualitative representation of terrain conditions and knowledge about these conditions on the likely areal concentration of each landslide type. CAMEL is highly modifiable and adaptable; new knowledge can be easily added, while existing knowledge can be changed to better match local knowledge and conditions. As such, CAMEL should not be viewed as a complete alternative to other earthquake-induced landslide models. CAMEL provides an open framework for incorporating other models, such as Newmark's displacement method, together with previously incompatible empirical and local knowledge. ?? 2009 ASCE.

  14. Landslide Hazard-Prevention in Balakot Region, Pakistan

    Directory of Open Access Journals (Sweden)

    Abdul Salam Soomro


    Full Text Available The earthquake triggered enormous landslides on 8th October 2005 in the various areas of Pakistan especially in Balakot Region. This research paper fulfilled the urge to develop alternative landslide planning based on the consideration of landslide preventing measures using GIS (Geographical Informaton Systems techniques. This specific type of land use planning differs from traditional type of land use planning due to consideration of the probable hazard of landslide disaster by applying zonation methodology for finding the appropriate suitable areas for various development purposes. The various parameters e.g. elevation, slope angle, forest/ vegetations, faults, landslide zones, and rainfall were utilized as GIS data themes in the vector format. The different GIS techniques were used: (i Clipping the data layers; (ii Spatial analysis by converting the vector layers into raster format; (iii Classification of data themes into certain classes; (iv Overlaying the data themes and (v Map calculation techniques through GIS standard software. This applied research has found that various different regions such as high suitable, moderate suitable, low suitable and unsuitable may be considered as preventive measures from the probable hazard of the landslide disaster in future for rehabilitation and redevelopment purpose which can save human lives, residential and commercial infrastructure in future. It is believed that the various predicted regions for preventing landslide hazards can be very beneficial to the decision makers for the redevelopment of the region in future.

  15. Regional rainfall thresholds for landslide occurrence using a centenary database (United States)

    Vaz, Teresa; Luís Zêzere, José; Pereira, Susana; Cruz Oliveira, Sérgio; Garcia, Ricardo A. C.; Quaresma, Ivânia


    This work proposes a comprehensive method to assess rainfall thresholds for landslide initiation using a centenary landslide database associated with a single centenary daily rainfall data set. The method is applied to the Lisbon region and includes the rainfall return period analysis that was used to identify the critical rainfall combination (cumulated rainfall duration) related to each landslide event. The spatial representativeness of the reference rain gauge is evaluated and the rainfall thresholds are assessed and calibrated using the receiver operating characteristic (ROC) metrics. Results show that landslide events located up to 10 km from the rain gauge can be used to calculate the rainfall thresholds in the study area; however, these thresholds may be used with acceptable confidence up to 50 km from the rain gauge. The rainfall thresholds obtained using linear and potential regression perform well in ROC metrics. However, the intermediate thresholds based on the probability of landslide events established in the zone between the lower-limit threshold and the upper-limit threshold are much more informative as they indicate the probability of landslide event occurrence given rainfall exceeding the threshold. This information can be easily included in landslide early warning systems, especially when combined with the probability of rainfall above each threshold.

  16. Studying Landslide Displacements in Megamendung (Indonesia Using GPS Survey Method

    Directory of Open Access Journals (Sweden)

    Hasanuddin Z. Abidin


    Full Text Available Landslide is one of prominent geohazards that frequently affects Indonesia, especially in the rainy season. It destroys not only environment and property, but usually also causes deaths. Landslide monitoring is therefore very crucial and should be continuously done. One of the methods that can have a contribution in studying landslide phenomena is repeated GPS survey method. This paper presents and discusses the operational performances, constraints and results of GPS surveys conducted in a well known landslide prone area in West Java (Indonesia, namely Megamendung, the hilly region close to Bogor. Three GPS surveys involving 8 GPS points have been conducted, namely on April 2002, May 2003 and May 2004, respectively. The estimated landslide displacements in the area are relatively quite large in the level of a few dm to a few m. Displacements up to about 2-3 m were detected in the April 2002 to May 2003 period, and up to about 3-4 dm in the May 2003 to May 2004 period. In both periods, landslides in general show the northwest direction of displacements. Displacements vary both spatially and temporally. This study also suggested that in order to conclude the existence of real and significant displacements of GPS points, the GPS estimated displacements should be subjected to three types of testing namely: the congruency test on spatial displacements, testing on the agreement between the horizontal distance changes with the predicted direction of landslide displacement, and testing on the consistency of displacement directions on two consecutive periods.

  17. Development research of expert system for diagnosis of landslide

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Toru; Soeda, Yoshio; Nakamura, Hirohisa [Kansai Electric Power Co. Inc., Osaka (Japan)


    Measures against landslides are based upon a judgment to be made by combined application of professional knowledge of the scientific fields such as topography and geology, etc. and Kansai Electric Power Co. tried to construct a technical support system for preliminary diagnosis of landslide with which field engineers can easily utilize expert knowledge and to which artificial intelligence (AI) is applied. This system is to diagnose preliminarily the existence of such a landslide-prone area which is likely to hamper the project concerned at its early stage and after examination, those considered to be appropriate for the purpose were selected from among the artificial intelligence tools already developed. And as the knowledge base, knowledge was arranged in order with regard to the common features of landslide-prone areas, classification of landslide spots, landslide-prone topography and confusing topography, and procedures as well as remarks to be taken in reading the landslide topography, and was transformed as rule in order to input as the knowledge base into a computer. The system used the aerial photography interpretation theory as the base for its expert knowledge base and the materials necessary therefore were confined to easily obtainable aerial photographs and topographical maps. The system was prepared with a general purpose personal computer. 4 figs., 1 tab.

  18. Cold-water coral banks and submarine landslides: a review (United States)

    de Mol, Ben; Huvenne, Veerle; Canals, Miquel


    This paper aims to review the relation between cold-water coral bank development and submarine landslides. Both are common features on continental margins, but so far it has not been reviewed which effect—if at all—they may have upon each other. Indirect and direct relations between coral banks and landslides are evaluated here, based on four case studies: the Magellan Mound Province in the Porcupine Seabight, where fossil coral banks appear partly on top of a buried slide deposit; the Sula Ridge Reef Complex and the Storegga landslide both off mid-Norway; and the Mauritania coral bank province, associated with the Mauritanian Slide Complex. For each of these locations, positive and negative relationships between both features are discussed, based on available datasets. Locally submarine landslides might directly favour coral bank development by creating substratum where corals can settle on, enhancing turbulence due to abrupt seabed morphological variations and, in some cases, causing fluid seepage. In turn, some of these processes may contribute to increased food availability and lower sedimentation rates. Landslides can also affect coral bank development by direct erosion of the coral banks, and by the instantaneous increase of turbidity, which may smother the corals. On the other hand, coral banks might have a stabilising function and delay or stop the headwall retrogradation of submarine landslides. Although local relationships can be deduced from these case studies, no general and direct relationship exists between submarine landslides and cold-water coral banks.

  19. State of the art of national landslide databases in Europe and their potential for assessing landslide susceptibility, hazard and risk (United States)

    Van Den Eeckhaut, Miet; Hervás, Javier


    A landslide inventory is the most important information source for quantitative zoning of landslide susceptibility, hazard and risk. It should give insight into the location, date, type, size, activity and causal factors of landslides as well as resultant damage. In Europe, many countries have created or are creating national and/or regional landslide databases (LDBs). Yet little is known on their contents, completeness, format, structure, language use and accessibility, and hence on their ability to perform national or transnational landslide zoning. Therefore, this study presents a detailed analysis of existing national LDBs in the EU member states, EU official candidate and potential candidate countries, and EFTA countries, and their possible use for landslide zoning. These national LDBs were compared with a subset of 22 regional databases. Twenty-two out of 37 contacted European countries currently have national LDBs, and six other countries have only regional LDBs. In total, the national LDBs contain 633,696 landslides, of which 485,004 are located in Italy, while Austria, the Czech Republic, France, Norway, Poland, Slovakia, and the UK also have > 10,000 landslides in their LDBs. National LDBs are generally created in the official language of each country and 58% of them contain other natural hazards (e.g. floods and sinkholes). About 68% of the LDBs contain less than 50% of all landslides in each country, but a positive observation is that 60% of the LDBs are updated at least once a year or after a major event. Most landslide locations are collected with traditional methods such as field surveys, aerial photo interpretation and analysis of historical records. Currently, integration of landslide information from different national LDBs is hampered because of differences in language and classification systems for landslide type and activity. Other problems are that currently only half of the national LDBs have a direct link between spatial and alphanumeric

  20. Tree-root control of shallow landslides (United States)

    Cohen, Denis; Schwarz, Massimiliano


    Tree roots have long been recognized to increase slope stability by reinforcing the strength of soils. Slope stability models usually include the effects of roots by adding an apparent cohesion to the soil to simulate root strength. No model includes the combined effects of root distribution heterogeneity, stress-strain behavior of root reinforcement, or root strength in compression. Recent field observations, however, indicate that shallow landslide triggering mechanisms are characterized by differential deformation that indicates localized activation of zones in tension, compression, and shear in the soil. Here we describe a new model for slope stability that specifically considers these effects. The model is a strain-step discrete element model that reproduces the self-organized redistribution of forces on a slope during rainfall-triggered shallow landslides. We use a conceptual sigmoidal-shaped hillslope with a clearing in its center to explore the effects of tree size, spacing, weak zones, maximum root-size diameter, and different root strength configurations. Simulation results indicate that tree roots can stabilize slopes that would otherwise fail without them and, in general, higher root density with higher root reinforcement results in a more stable slope. The variation in root stiffness with diameter can, in some cases, invert this relationship. Root tension provides more resistance to failure than root compression but roots with both tension and compression offer the best resistance to failure. Lateral (slope-parallel) tension can be important in cases when the magnitude of this force is comparable to the slope-perpendicular tensile force. In this case, lateral forces can bring to failure tree-covered areas with high root reinforcement. Slope failure occurs when downslope soil compression reaches the soil maximum strength. When this occurs depends on the amount of root tension upslope in both the slope-perpendicular and slope-parallel directions. Roots

  1. Tree-root control of shallow landslides

    Directory of Open Access Journals (Sweden)

    D. Cohen


    Full Text Available Tree roots have long been recognized to increase slope stability by reinforcing the strength of soils. Slope stability models usually include the effects of roots by adding an apparent cohesion to the soil to simulate root strength. No model includes the combined effects of root distribution heterogeneity, stress-strain behavior of root reinforcement, or root strength in compression. Recent field observations, however, indicate that shallow landslide triggering mechanisms are characterized by differential deformation that indicates localized activation of zones in tension, compression, and shear in the soil. Here we describe a new model for slope stability that specifically considers these effects. The model is a strain-step discrete element model that reproduces the self-organized redistribution of forces on a slope during rainfall-triggered shallow landslides. We use a conceptual sigmoidal-shaped hillslope with a clearing in its center to explore the effects of tree size, spacing, weak zones, maximum root-size diameter, and different root strength configurations. Simulation results indicate that tree roots can stabilize slopes that would otherwise fail without them and, in general, higher root density with higher root reinforcement results in a more stable slope. The variation in root stiffness with diameter can, in some cases, invert this relationship. Root tension provides more resistance to failure than root compression but roots with both tension and compression offer the best resistance to failure. Lateral (slope-parallel tension can be important in cases when the magnitude of this force is comparable to the slope-perpendicular tensile force. In this case, lateral forces can bring to failure tree-covered areas with high root reinforcement. Slope failure occurs when downslope soil compression reaches the soil maximum strength. When this occurs depends on the amount of root tension upslope in both the slope-perpendicular and slope

  2. Chesapeake Bay under stress (United States)

    According to extensive data obtained over its 13,000 km of shoreline, the Chesapeake Bay has been suffering a major, indeed unprecedented, reduction in submerged vegetation. Chesapeake Bay is alone in experiencing decline in submerged vegetation. Other estuary systems on the east coast of the United States are not so affected. These alarming results were obtained by the synthesis of the findings of numerous individual groups in addition to large consortium projects on the Chesapeake done over the past decade. R. J. Orth and R. A. Moore of the Virginia Institute of Marine Science pointed to the problem of the severe decline of submerged grasses on the Bay and along its tributaries. In a recent report, Orth and Moore note: “The decline, which began in the 1960's and accelerated in the 1970's, has affected all species in all areas. Many major river systems are now totally devoid of any rooted vegetation” (Science, 222, 51-53, 1983).

  3. Landslides Induced by 2015 Gorkha Earthquake and Their Continuous Evolution Post 2015 and 2016-Monsoon (United States)

    Spear, B.; Haritashya, U. K.; Kargel, J. S.


    Gorkha Nepal has been a hot bed of landslide activity since the 7.8 magnitude earthquake that occurred on April 25th 2015. Even though previous studies have mapped and analyzed the landslides that were directly related to the earthquake, this research maps and analyzes the landslides that occurred during monsoon or after monsoon season in 2015 and 2016. Specifically, our objectives included monitoring post-earthquake landslide evolution and reactivation. We also observed landslides which occurred in the steep side slopes of various small rivers and threatened to block the flow of river. Consequently, we used Landsat, Sentinel, ASTER and images available at Google Earth Engine to locate, map, and analyze these landslides. Our preliminary result indicates 5,270 landslides, however 957 of these landslides occurred significantly after the earthquake. Of the 957 landslides, 508 of them occurred during the monsoon season of 2015 and 48 in the 2016 monsoon season. As well as locating and mapping these landslides, we were able to identify that there were 22 landslides blocking rivers and 24 were reactivated. Our result and landslide density maps clearly identifies zones that are prone to landslides. For example, the steepest areas, such as the Helambu or Langtang region, have a very high concentration of landslides since the earthquake. Furthermore, landslides with the largest area were often nearby each other in very steep regions. This research can be used to determine which areas in the Gorkha Nepal region are safe to use and which areas are high risk.

  4. Coulomb Mechanics And Landscape Geometry Explain Landslide Size Distribution (United States)

    Jeandet, L.; Steer, P.; Lague, D.; Davy, P.


    It is generally observed that the dimensions of large bedrock landslides follow power-law scaling relationships. In particular, the non-cumulative frequency distribution (PDF) of bedrock landslide area is well characterized by a negative power-law above a critical size, with an exponent 2.4. However, the respective role of bedrock mechanical properties, landscape shape and triggering mechanisms on the scaling properties of landslide dimensions are still poorly understood. Yet, unravelling the factors that control this distribution is required to better estimate the total volume of landslides triggered by large earthquakes or storms. To tackle this issue, we develop a simple probabilistic 1D approach to compute the PDF of rupture depths in a given landscape. The model is applied to randomly sampled points along hillslopes of studied digital elevation models. At each point location, the model determines the range of depth and angle leading to unstable rupture planes, by applying a simple Mohr-Coulomb rupture criterion only to the rupture planes that intersect downhill surface topography. This model therefore accounts for both rock mechanical properties, friction and cohesion, and landscape shape. We show that this model leads to realistic landslide depth distribution, with a power-law arising when the number of samples is high enough. The modeled PDF of landslide size obtained for several landscapes match the ones from earthquakes-driven landslides catalogues for the same landscape. In turn, this allows us to invert landslide effective mechanical parameters, friction and cohesion, associated to those specific events, including Chi-Chi, Wenchuan, Niigata and Gorkha earthquakes. The cohesion and friction ranges (25-35 degrees and 5-20 kPa) are in good agreement with previously inverted values. Our results demonstrate that reduced complexity mechanics is efficient to model the distribution of unstable depths, and show the role of landscape variability in landslide size

  5. Monitoring and Warning of Landslides Based On Rainfall (United States)

    Yudhbir, Y.

    Management issues of landslide hazards assume much greater significance in poorest segments of society living in landslide risk prone hilly areas in developing countries. Analysis of the temporal recurrence of landslides shows that disastrous events occur with a frequency higher than the social and economic capacity of these societies to recover from previous events. In the context of landslide hazard management in In- dian Himalayan states this problem assumes much greater significance. Majority of the population lives on hill slopes which experience repeated landsliding activity es- pecially during the summer monsoon rains. Considering the high cost of structural control measures and the lack of necessary spatial database in respect of Quaternary geology, detailed topography and geohydrology etc., there is an acute need to develop a monitoring and warning system which is economical, easy to operate and does not require high technological inputs. Since most of the landslides in these areas are triggered by high incidence of rain, it appears attractive to explore development of a monitoring and warning network based on critical rainfall intensity thresholds. Such an option for management of landslide hazards would also provide useful meteorological data required for assessment of wa- ter resources, soil loss due to erosion, agricultural practices and flood incidence. In this paper, available approaches to the prediction and warning of landslide based on rainfall data will be critically reviewed. Various criteria recommended in litera- ture for threshold rainfall values in rain induced ground movements/failures would be compared and these relationships will be contrasted with the limited data available for the Indian Himalayan landslides. A plan for a network of automatic rain gauges and a suitable warning system will be discussed.

  6. Implications of climate change on landslide hazard in Central Italy. (United States)

    Alvioli, Massimiliano; Melillo, Massimo; Guzzetti, Fausto; Rossi, Mauro; Palazzi, Elisa; von Hardenberg, Jost; Brunetti, Maria Teresa; Peruccacci, Silvia


    The relation between climate change and its potential effects on the stability of slopes remains an open issue. For rainfall induced landslides, the point consists in determining the effects of the projected changes in the duration and amounts of rainfall that can initiate slope failures. We investigated the relationship between fine-scale climate projections obtained by downscaling and the expected modifications in landslide occurrence in Central Italy. We used rainfall measurements taken by 56 rain gauges in the 9-year period 2003-2011, and the RainFARM technique to generate downscaled synthetic rainfall fields from regional climate model projections for the 14-year calibration period 2002-2015, and for the 40-year projection period 2010-2049. Using a specific algorithm, we extracted a number of rainfall events, i.e. rainfall periods separated by dry periods of no or negligible amount of rain, from the measured and the synthetic rainfall series. Then, we used the selected rainfall events to forcethe Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Model TRIGRS v. 2.1. We analyzed the results in terms of variations (or lack of variations) in the rainfall thresholds for the possible initiation of landslides, in the probability distribution of landslide size (area), and in landslide hazard. Results showed that the downscaled rainfall fields obtained by RainFARM can be used to single out rainfall events, and to force the slope stability model. Results further showed that while the rainfall thresholds for landslide occurrence are expected to change in future scenarios, the probability distribution of landslide areas are not. We infer that landslide hazard in the study area is expected to change in response to the projected variations in the rainfall conditions. We expect our results to contribute to regional investigations of the expected impact of projected climate variations on slope stability conditions and on landslide hazards. Copyright

  7. Susceptibility analysis of landslide in Chittagong City Corporation Area, Bangladesh

    Directory of Open Access Journals (Sweden)

    Sourav Das


    Full Text Available In Chittagong city, landslide phenomena is the most burning issue which causes great problems to the life and properties and it is increasing day by day and becoming one of the main problems of city life. On 11 June 2007, a massive landslide happened in Chittagong City Corporation (CCC area, a large number of foothill settlements and slums were demolished; more than 90 people died and huge resource destruction took place. It is therefore essential to analyze the landslide susceptibility for CCC area to prepare mitigation strategies as well as assessing the impacts of climate change. To assess community susceptibility of landslide hazard, a landslide susceptibility index map has been prepared using analytical hierarchy process (AHP model based on geographic information system (GIS and remote sensing (RS and its susceptibility is analyzed through community vulnerability assessment tool (CVAT. The major findings of the research are 27% of total CCC area which is susceptible to landslide hazard and whereas 6.5 areas are found very highly susceptible. The landslide susceptible areas of CCC have also been analyzed in respect of physical, social, economic, environmental and critical facilities and it is found that the overall CCC area is highly susceptible to landslide hazard. So the findings of the research can be utilized to prioritize risk mitigation investments, measures to strengthen the emergency preparedness and response mechanisms for reducing the losses and damages due to future landslide events. DOI: International Journal of Environment Vol.4(2 2015: 157-181

  8. Methods of Measuring and Mapping of Landslide Areas (United States)

    Skrzypczak, Izabela; Kokoszka, Wanda; Kogut, Janusz; Oleniacz, Grzegorz


    The problem of attracting new investment areas and the inability of current zoning areas, allows us to understand why it is impossible to completely rule out building on landslide areas. Therefore, it becomes important issue of monitoring areas at risk of landslides. Only through appropriate monitoring and proper development of measurements resulting as maps of areas at risk of landslides enables us to estimate the risk and the relevant economic calculation for the realization of the anticipated investment in such areas. The results of monitoring of the surface and in-depth of the landslides are supplemented with constant observation of precipitation. The previous analyses and monitoring of landslides show that some of them are continuously active. GPS measurements, especially with laser scanning provide a unique activity data acquired on the surface of each individual landslide. The development of high resolution numerical models of terrain and the creation of differential models based on subsequent measurements, informs us about the size of deformation, both in units of distance (displacements) and volume. The compatibility of the data with information from in-depth monitoring allows the generation of a very reliable in-depth model of landslide, and as a result proper calculation of the volume of colluvium. Programs presented in the article are a very effective tool to generate in-depth model of landslide. In Poland, the steps taken under the SOPO project i.e. the monitoring and description of landslides are absolutely necessary for social and economic reasons and they may have a significant impact on the economy and finances of individual municipalities and also a whole country economy.

  9. Mobile Bay turbidity study (United States)

    Crozier, G. F.; Schroeder, W. W.


    The termination of studies carried on for almost three years in the Mobile Bay area and adjacent continental shelf are reported. The initial results concentrating on the shelf and lower bay were presented in the interim report. The continued scope of work was designed to attempt a refinement of the mathematical model, assess the effectiveness of optical measurement of suspended particulate material and disseminate the acquired information. The optical characteristics of particulate solutions are affected by density gradients within the medium, density of the suspended particles, particle size, particle shape, particle quality, albedo, and the angle of refracted light. Several of these are discussed in detail.

  10. Probabilistic clustering of rainfall condition for landslide triggering (United States)

    Rossi, Mauro; Luciani, Silvia; Cesare Mondini, Alessandro; Kirschbaum, Dalia; Valigi, Daniela; Guzzetti, Fausto


    Landslides are widespread natural and man made phenomena. They are triggered by earthquakes, rapid snow melting, human activities, but mostly by typhoons and intense or prolonged rainfall precipitations. In Italy mostly they are triggered by intense precipitation. The prediction of landslide triggered by rainfall precipitations over large areas is commonly based on the exploitation of empirical models. Empirical landslide rainfall thresholds are used to identify rainfall conditions for the possible landslide initiation. It's common practice to define rainfall thresholds by assuming a power law lower boundary in the rainfall intensity-duration or cumulative rainfall-duration space above which landslide can occur. The boundary is defined considering rainfall conditions associated to landslide phenomena using heuristic approaches, and doesn't consider rainfall events not causing landslides. Here we present a new fully automatic method to identify the probability of landslide occurrence associated to rainfall conditions characterized by measures of intensity or cumulative rainfall and rainfall duration. The method splits the rainfall events of the past in two groups: a group of events causing landslides and its complementary, then estimate their probabilistic distributions. Next, the probabilistic membership of the new event to one of the two clusters is estimated. The method doesn't assume a priori any threshold model, but simple exploits the real empirical distribution of rainfall events. The approach was applied in the Umbria region, Central Italy, where a catalogue of landslide timing, were obtained through the search of chronicles, blogs and other source of information in the period 2002-2012. The approach was tested using rain gauge measures and satellite rainfall estimates (NASA TRMM-v6), allowing in both cases the identification of the rainfall condition triggering landslides in the region. Compared to the other existing threshold definition methods, the prosed

  11. Supporting response with science: the Oso, Washington, landslide (United States)

    Godt, J.


    On 22 March 2014 a large, rapidly moving landslide impacted the community of Steelhead Haven, near Oso, Washington, killing 43 people. The slide displaced about 8 million m3 of sand and silt from a 200-m high glacial terrace destroying 40 homes and burying more than 1.0 km of State Route 530. The landslide temporarily dammed the North Fork of the Stillaguamish River flooding an area of about 1.4 km2. The unusually long travel distance, in excess of 700 m from the base of the slope, and apparent speed of the slide led to the great loss of life and destruction. Landslide science was critical in supporting the response to the disaster. Landslide monitoring, process understanding, pre- and post-event high-resolution digital topography, and numerical simulations were used to advise search operations. Recognizing that buildings and their contents were swept tens to hundreds of meters from their original locations, maps of deposit thickness, and estimates of landslide trajectories were used to develop safer and more efficient search strategies. Teams of county, state, and federal scientists, engineers, and specialists were formed to assess the stability of the landslide dam and to monitor stream flow and the level of the lake impounded by the slide, and to assess the geomorphic response of the river to the landslide for gauging future effects on flood hazards and aquatic ecosystems. Another scientific team assessed the threat of additional landslide activity to search operations. This team's activities included establishing a communications protocol among landslide watch officers and search operations, deploying instrument platforms developed for use on volcanoes (Spiders) to remotely detect ground movement by means of GPS technology and to detect vibrations indicative of landslide movement using seismometers. The team was responsible for monitoring and integrating data from the Spiders and other instruments and making determinations with regards to the potential for

  12. Landslides susceptibility mapping at Gunung Ciremai National Park (United States)

    Faizin; Nur, Bambang Azis


    In addition to agriculture, tourism became one of primary economic income for communities around Mount Ciremai, West, Java. Unfortunately, the landscape of West Java has many potential causes to disasters, mainly landslides. Mapping of disaster susceptibility area is needed as a consideration of tourism planning. The study was conducted in Gunung Ciremai National Park, West Java. This paper propose a methodology to map landslides susceptibilities based on spatial data. Using Geographic Information System tools, several environmental parameters such as slope, land use, elevation, and lithology are scored to build a landslide susceptibility map. Then, susceptibility map is overlaid with Utilization Zone.

  13. Multi-method characterization of a landslide in Champagne vineyards: the case study of the Jacotines landslide (Marne, France) (United States)

    Nicolas, Bollot; Guillaume, Pierre; Gilles, Grandjean


    Key words : landslide, Champagne vineyards , geomorphology, geophysical data, superficial structure The Champagne region is strongly impacted by landslides. Usually inactive, these landslides suffer from partial reactivations leading to important damages, especially when they occur in the vineyards. In the Marne valley, and particularly in the center of Champagne vineyards area (Reuil), the Jacotines site is representative of such landslides since it presents typical surface characteristics widely observed in the region. However, its size, and especially its internal structure, can't be deduced from the surface analysis only. The aim of this work is to combine surface patterns analysis, geophysical data and borehole data to produce an interpretative model of the landslide. Preliminary geomorphological cartography was used for determining the influence of the landslide. From this information, geophysical investigations were carried out to image the internal structure of the landslide. Geophysical data fusion (combination of seismic and geoelectrical tomograms) was used to estimate the mechanical behavior and the fissuring pattern of the slope. Three transverse and longitudinal tomograms were used to define an heterogeneous area between 20 and 50 meters depth and a weathered zone from 0 to 10-20 meters depth. A 60 meters depth borehole on the main transverse tomogram found the shear plane and clarified the structure of the heterogeneous area as well as the uppermost weathered layer composed by debris flows resulting from partial reactivations processes.

  14. Geotechical Investigation of Landslides in Gurpinar Region (United States)

    Karabulut, S.; Imre, N.; Dalgic, S.; Ozcep, F.


    Gürpinar in Beylikdüzü district in Istanbul, Rapid and uncontrolled construction have been exposed due to the current visual. Although to the previous zoning plan to covered a large part of the study area was recommended to use as green space, today's regulations have begun to define these areas as the areas mostly precautionary. With the development of engineering technology and knowledge, these areas were allowed to open of new structures to take necessary precautions. With increase in the effective construction in these regions, the existing slopes has led to start due to imbalance of mass movements. By using topographic map (1 / 5000 scale) and satellite images were examined in the region, the boundaries of existing landslides have been identified within the scope of this study. These areas are Çukurlar, Pınarkent, Pekmez and Onbeşevler. In addition to geophysical studies previously performed in the region; Seismic Reflection, Surface Wave Analysis (Active and Passive Source) and ground penetrating radar measurements were done. The geometry of surface planes and its depth, sand-gravel lenses, border of saturated clay units and the dynamic elastic parameters have been determined by using geophysical studies. The target depth of each method related to the properties of used sources or antenna and features of equipment. In Onbeşevler selected as pilot regions for georadar measurements, different water saturation at different depths s have been identified by using information taken from a depth of 30 meters. As a result of the geophysical studies, each in a landslide area, many slip plane have been identified and are given in sections. Geological cross-sections created for the workspace by using the drilling data and the pits belong to private companies and government agencies in the region. Inside the border of each landslides, the slope stability analysis done by using geological cross-sections and its physical parameters. Slope stability analysis made by

  15. Richards Bay effluent pipeline

    CSIR Research Space (South Africa)

    Lord, DA


    Full Text Available of major concern identified in the effluent are the large volume of byproduct calcium sulphate (phosphogypsum) which would smother marine life, high concentrations of fluoride highly toxic to marine life, heavy metals, chlorinated organic material... ........................ 9 THE RICHARDS BAY PIPELINE ........................................ 16 Environmental considerations ................................... 16 - Phosphogypsum disposal ................................... 16 - Effects of fluoride on locally occurring...

  16. Bayes and Networks

    NARCIS (Netherlands)

    Gao, F.


    The dissertation consists of research in three subjects in two themes—Bayes and networks: The first studies the posterior contraction rates for the Dirichlet-Laplace mixtures in a deconvolution setting (Chapter 1). The second subject regards the statistical inference in preferential attachment

  17. Rainfall-triggered landslides, anthropogenic hazards, and mitigation strategies

    Directory of Open Access Journals (Sweden)

    M. C. Larsen


    Full Text Available Rainfall-triggered landslides are part of a natural process of hillslope erosion that can result in catastrophic loss of life and extensive property damage in mountainous, densely populated areas. As global population expansion on or near steep hillslopes continues, the human and economic costs associated with landslides will increase. Landslide hazard mitigation strategies generally involve hazard assessment mapping, warning systems, control structures, and regional landslide planning and policy development. To be sustainable, hazard mitigation requires that management of natural resources is closely connected to local economic and social interests. A successful strategy is dependent on a combination of multi-disciplinary scientific and engineering approaches, and the political will to take action at the local community to national scale.

  18. Landslide rehabilitation with geo synthetics in open coal mine Oslomej

    International Nuclear Information System (INIS)

    Dimitrievski, Ljupcho; Ilievska, Frosina; Ilievski, Darko


    In November 2002 stability is violated and landslides are registered in open coal mine Oslomej, Republic of Macedonia. Around the profile IV existing open irrigation channel was interrupted and landslide was extended to the regional way R421 Kicevo - Oslomej. The landslide was classified like big and dangerous, including danger for disruption of the regional road and pipeline Studencica - Oslomej for supplying of thermal power plant Oslomej with technical water. According to the proposed solution, main project design for landslide rehabilitation was prepared with using geo synthetics Stabilenka 200/45. In fill is local soil material which had been placed and compacted in layers, it had formed a composite construction. Stabilenka acts as a reinforcement due to its ability to absorb tensile forces. With the design solution two retaining walls of reinforced soil and complete drainage system of geo composite materials had been constructed This paper deals with details of the design and the construction. (Author)

  19. Recent advances in modeling landslides and debris flows

    CERN Document Server


    Landslides and debris flows belong to the most dangerous natural hazards in many parts of the world. Despite intensive research, these events continue to result in human suffering, property losses, and environmental degradation every year. Better understanding of the mechanisms and processes of landslides and debris flows will help make reliable predictions, develop mitigation strategies and reduce vulnerability of infrastructure. This book presents contributions to the workshop on Recent Developments in the Analysis, Monitoring and Forecast of Landslides and Debris Flow, in Vienna, Austria, September 9, 2013. The contributions cover a broad spectrum of topics from material behavior, physical modelling over numerical simulation to applications and case studies. The workshop is a joint event of three research projects funded by the European Commission within the 7th Framework Program: MUMOLADE (Multiscale modelling of landslides and debris flows,, REVENUES (Numerical Analysis of Slopes with V...

  20. GIS-based assessment of landslide susceptibility using certainty ...

    Indian Academy of Sciences (India)

    tion systems (GIS) using different models. Many of these ... as spatial multicriteria decision analysis (MCDA) approach ... 2013), support vec- ... Landslide susceptibility assessment using mathematical methods in GIS, Qianyang China 1401.

  1. application of geospatial tools for landslide hazard assessment

    African Journals Online (AJOL)


    datasets used in this study included digital elevation model, soils, precipitation ... was generated that showed risk levels of various areas in Uganda. .... There is acknowledged difficulty in quantifying the nature of hazards caused by a landslide.

  2. A comparative study on the landslide susceptibility mapping using ...

    Indian Academy of Sciences (India)

    from faults, lithology, normalized difference vegetation index (NDVI), sediment transport index (STI), stream power ... economic losses and creating high maintenance costs, are ..... evidence method to landslide susceptibility map- ping using ...

  3. Predictive susceptibility analysis of typhoon induced landslides in Central Taiwan (United States)

    Shou, Keh-Jian; Lin, Zora


    Climate change caused by global warming affects Taiwan significantly for the past decade. The increasing frequency of extreme rainfall events, in which concentrated and intensive rainfalls generally cause geohazards including landslides and debris flows. The extraordinary, such as 2004 Mindulle and 2009 Morakot, hit Taiwan and induced serious flooding and landslides. This study employs rainfall frequency analysis together with the atmospheric general circulation model (AGCM) downscaling estimation to understand the temporal rainfall trends, distributions, and intensities in the adopted Wu River watershed in Central Taiwan. To assess the spatial hazard of the landslides, landslide susceptibility analysis was also applied. Different types of rainfall factors were tested in the susceptibility models for a better accuracy. In addition, the routes of typhoons were also considered in the predictive analysis. The results of predictive analysis can be applied for risk prevention and management in the study area.

  4. Review of the occurrences and influencing factors of landslides in ...

    African Journals Online (AJOL)


    environmental hazards in many of the hilly and mountainous terrains of both the developed ..... British Columbia, the Himalayan foothills, and Japan. .... For a successful landslide risk management program, there need to be policies, legislation.

  5. Landslide susceptibility zonation in part of Tehri reservoir region ...

    Indian Academy of Sciences (India)

    Validation of the model was performed by using cumulative ..... thrusts, folds and joints of varying shape and size ...... Lee S, Choi J and Min K 2002 Landslide susceptibility analy- ... cross-validation in three test areas using a frequency.

  6. Social Geology and Landslide Disaster Risk Reduction in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Jayasingha P


    Full Text Available AbstractLandslide disaster risk reduction is presently a challenging task facing by Sri Lankangeologists. Increasing trend of population growth in Sri Lanka has adversely affected thestability of central highland due to various human activities. Among them establishment ofhuman settlements and change in land use pattern have become a serious issue in triggeringland instabilities in central highland of the country. National Building Research Oragnisationwhich is the main focal point in land slide disaster risk reduction in Sri Lanka has takenvaluable and timely needed actions including preparation of landslide hazard zonation maps,early warnings and mitigations. Though the landslide is a geological phenomenon, it is highlyinteracted with human societies. Hence managing the issues arising with the landslideoccurrence should be addressed with a sociological approach. This new approach is known asSocio Geological approach which is discussed here.Key words: Landslide, Geology, Socio Geology, Social Geologist

  7. A preliminary study of landslide gouge dating by TL technique

    Energy Technology Data Exchange (ETDEWEB)

    Fengju, Ji; Jianping, Li [Inst. of Geology, National Seismological Bereau, Beijing (China); Mingda, Liu [Inst. of Crustal Dynamics, SSB, Beijing (China)


    The key to date slipping of landslide by TL method is whether the temperature and pressure caused by slipping can lead the original TL to 'zero'for some minerals within the slipping band. For this purpose, the simulated experiments under different temperature-pressure were made and the TL annealing effect of landslide gouge was studied. The results show that the frictional heating caused during slipping is a main factor leading the mineral's TL to decrease on the slip plane and that increment of temperature is in close relation with strength of shear stress, thickness of landslide gouge and amount of displacement. As an example, the slipping age of a paleo-landslide at Huangtupo, Hubei Province, has been dated to be about 140 ka.

  8. Some rapid and long traveled landslides triggered by the May 12, 2008 Sichuan earthquake (United States)

    Wang, G.; Kamai, T.; Chigira, M.; Wu, X. Y.; Zhang, D. X.


    On May 12, 2008, a 7.9M earthquake struck Sichuan province of China, causing a huge number of death and injuries, and great loss of properties, becoming the most damaging earthquake since the 1976 Tangshan earthquake, in China. The collapse of buildings during the earthquake is the main reason for the casualties. There are a huge number of landslides that had been triggered by this earthquake. Almost all the roads to the mountainous areas had been blocked and many dams were formed by the displaced landslide materials, resulting in great difficulties for the aftershock rescue activities. Also a big portion of the casualties was directly caused by the landslides. The authors had reconnaissance field trips of the landslides, and performed preliminary investigation on some of the catastrophic ones. In this report, four landslides, i.e., Xiejiadian landslide in Pengzhou city, Donghekou landslide and Magongxiang landslide in Qingchuan County, and Niujuangou landslide on the epicenter area of Yingxiu Town, are introduced. The characteristics of deposited landslide masses in Donghekou landslide were investigated by means of a multichannel surface wave technique. Two earthquake recorders were installed at the upper part and deposit area of Donghekou landslide. The seismic responses of different parts of the landslides were monitored, and recorded successfully during the aftershocks that occurred in Qingchuan County on July 24, 2008. Also the drained and undrained dynamic shear behaviors of samples from the landslide areas were examined. Some preliminary analyzing results will be presented in this report.

  9. Landslide inventory along a pipeline corridor in the Mackenzie Valley, Northwest Territories

    Energy Technology Data Exchange (ETDEWEB)

    Couture, R.; Riopel, S. [Natural Resources Canada, Ottawa, ON (Canada). Geological Survey of Canada


    The route for the proposed Mackenzie Valley gas pipeline in the Northwest Territories includes areas that are known for widespread landsliding. Natural Resources Canada initiated a landslide mapping project in an effort to develop a synthesis of the types, regional distribution, and controlling factors of landslides in the region. The study area is covered by unconsolidated sediments dominated by morainal, lacustrine, and alluvial deposits. Three types of permafrost were mapped, notably continuous, extensive discontinuous, and intermediate discontinuous. A preliminary inventory of 1,807 landslides and other natural terrain hazard features were identified by air photo interpretations. The landslide limits were digitized and catalogued in the Mackenzie Valley landslide spatial database. Several attributes were recorded for each landslide feature, including unique identifiers, landslide type, size, location, morphological parameters, and relative age. The landslide distribution was then characterized. The results indicate an average density of one landslide per 5 km{sup 2}. The dominant landslide types are retrogressive thaw flows and active layer detachments, followed by rock falls, debris flows, earth slides, surficial landslides, and retrogressive thaw slides. Nearly half of all landslides took place in morainal deposits, 19 per cent in lacustrine sediments, 14 per cent in bedrock, and 13 per cent in glaciofluvial sediments. According to tone, texture, and vegetation regrowth attributes, 39 per cent of the landslides were classified as being older than 50 years, 39 per cent were 10 to 50 years old and 22 per cent were less than 10 years old.

  10. Adjustment of the problems of landslide GIS data (United States)

    Uchiyama, S.; Doshida, S.; Oyagi, N.; Shimizu, F.; Inokuchi, T.


    Information on the distribution of landslides is a basic type of data used by countries for disaster prevention. Since 1972, 1:50,000 landslide maps have been produced at the Japanese National Research Institute for Earth Science and Disaster Prevention. From October 2000, the institute has been producing landslide GIS data and transmitting these data over the web. The area that has been published so far covers over 80% of Japan. Presently, the number of diagrams printed are 980 (March 2012). In addition, 350,000 landslide GIS data graphs have been digitized with the same diagrams as a base. Twelve years have passed since this GIS data acquisition program was launched, and in that time, several problems have been identified. These problems are listed below. 1) Scarps do not become polygonized. 2) Landslides which extend over the boundaries of the printed graphs are divided into separate elements. 3) When the time taken to read and interpret the landslide data differs, the shape of the landslides can vary between diagrams. 4) There have been cases of inaccurate positions and shapes in landslide GIS data produced since 2005. 5) Obvious mistakes are present in the attribute data. The causes of such problems are as follows: 1) Lack of technical examination at the time of the start of the production of the landslide GIS data. 2) Limitations of the landslide GIS data editing systems which were developed separately. 3) Program bugs which occur during the conversion of information input to an individual editing system into general-purpose GIS data. 4) Problems which arise during the process of the production of landslide GIS data. This project at the National Research Institute for Earth Science and Disaster Prevention is planned to be completed in 2013. By the end of the project, we hope to present a catalogue of all identified problems and formulate a plan to resolve them, and pass them on to the next generation.; Problems: For the diagram, scarps are presented by

  11. Microseismic Events Detection on Xishancun Landslide, Sichuan Province, China (United States)

    Sheng, M.; Chu, R.; Wei, Z.


    On landslide, the slope movement and the fracturing of the rock mass often lead to microearthquakes, which are recorded as weak signals on seismographs. The distribution characteristics of temporal and spatial regional unstability as well as the impact of external factors on the unstable regions can be understand and analyzed by monitoring those microseismic events. Microseismic method can provide some information inside the landslide, which can be used as supplementary of geodetic methods for monitoring the movement of landslide surface. Compared to drilling on landslide, microseismic method is more economical and safe. Xishancun Landslide is located about 60km northwest of Wenchuan earthquake centroid, it keep deforming after the earthquake, which greatly increases the probability of disasters. In the autumn of 2015, 30 seismometers were deployed on the landslide for 3 months with intervals of 200 500 meters. First, we used regional earthquakes for time correction of seismometers to eliminate the influence of inaccuracy GPS clocks and the subsurface structure of stations. Due to low velocity of the loose medium, the travel time difference of microseismic events on the landslide up to 5s. According to travel time and waveform characteristics, we found many microseismic events and converted them into envelopes as templates, then we used a sliding-window cross-correlation technique based on waveform envelope to detect the other microseismic events. Consequently, 100 microseismic events were detected with the waveforms recorded on all seismometers. Based on the location, we found most of them located on the front of the landslide while the others located on the back end. The bottom and top of the landslide accumulated considerable energy and deformed largely, radiated waves could be recorded by all stations. What's more, the bottom with more events seemed very active. In addition, there were many smaller events happened in middle part of the landslide where released

  12. Geomodels of coseismic landslides environments in Central Chile. (United States)

    Serey, A.; Sepulveda, S. A.; Murphy, W.; Petley, D. N.


    Landslides are a major source of fatalities and damage during strong earthquakes in mountain areas. Detailed geomodels of coseismic landslides environments are essential parts of seismic landslide hazard analyses. The development of a site specific geological model is required, based on consideration of the regional and local geological and geomorphological history and the current ground surface conditions. An engineering geological model is any approximation of the geological conditions, at varying scales, created for the purpose of solving an engineering problem. In our case, the objective is the development of a methodology for earthquake-induced landslide hazard assessment applicable to urban/territorial planning and disaster prevention strategies assessment at a regional scale adapted for the Chilean tectonic conditions. We have developed the only 2 complete inventories of landslides triggered by earthquakes in Chile. The first from the Mw 6.2, shallow crustal Aysén earthquake in 2007. Second one from the Mw 8.8, megathrust subduction Maule earthquake in 2010. From the comparison of these 2 inventories with others from abroad, as well as analysis of large, prehistoric landslide inventories proposed as likely induced by seismic activity we have determined topographic, geomorphological, geological and seismic controlling factors in the occurrence of earthquake-triggered landslides. With the information collected we have defined different environments for generation of coseismic landslides based on the construction of geomodels. As a result we have built several geomodels in the Santiago Cordillera in central Chile (33°S), based upon the San Ramón Fault, a west-vergent reverse fault that outcrops at the edge of Santiago basin recently found to be active and a likely source of seismic activity in the future, with potential of triggering landslides in the Santiago mountain front as well as inland into the Mapocho and Maipo Cordilleran valleys. In conclusion

  13. Size distributions and failure initiation of submarine and subaerial landslides (United States)

    ten Brink, Uri S.; Barkan, R.; Andrews, B.D.; Chaytor, J.D.


    Landslides are often viewed together with other natural hazards, such as earthquakes and fires, as phenomena whose size distribution obeys an inverse power law. Inverse power law distributions are the result of additive avalanche processes, in which the final size cannot be predicted at the onset of the disturbance. Volume and area distributions of submarine landslides along the U.S. Atlantic continental slope follow a lognormal distribution and not an inverse power law. Using Monte Carlo simulations, we generated area distributions of submarine landslides that show a characteristic size and with few smaller and larger areas, which can be described well by a lognormal distribution. To generate these distributions we assumed that the area of slope failure depends on earthquake magnitude, i.e., that failure occurs simultaneously over the area affected by horizontal ground shaking, and does not cascade from nucleating points. Furthermore, the downslope movement of displaced sediments does not entrain significant amounts of additional material. Our simulations fit well the area distribution of landslide sources along the Atlantic continental margin, if we assume that the slope has been subjected to earthquakes of magnitude ??? 6.3. Regions of submarine landslides, whose area distributions obey inverse power laws, may be controlled by different generation mechanisms, such as the gradual development of fractures in the headwalls of cliffs. The observation of a large number of small subaerial landslides being triggered by a single earthquake is also compatible with the hypothesis that failure occurs simultaneously in many locations within the area affected by ground shaking. Unlike submarine landslides, which are found on large uniformly-dipping slopes, a single large landslide scarp cannot form on land because of the heterogeneous morphology and short slope distances of tectonically-active subaerial regions. However, for a given earthquake magnitude, the total area

  14. Mapping Landslides Susceptibility in a Traditional Northern Nigerian City (United States)

    Oluwafemi, Olawale A.; Yakubu, Tahir A.; Muhammad, Mahmud U.; Shitta, Nyofo; Akinwumiju, Akinola S.


    As a result of dearth of relevant information about Landslides Susceptibility in Nigeria, the monitoring and assessment appears intractable. Hence, the study developed a Remote Sensing approach to mapping landslides susceptibility, landuse and landcover analysis in Jos South LGA, Plateau State, Nigeria. Field Observation, SPOT 5 2009 and 2012, ASTER DEM 2009, Geological Map 2006, Topographical Map 1966 were used to map Landslide Susceptibility and Landuse /Lancover Analysis in the study area. Geospatial Analytical Operations employed using ArcGIS 10.3 and Erdas Imagine 2014 include Spatial Modeling, Vectorization, Pre-lineament Extraction, Image Processing among others. Result showed that 72.38 % of the study area is underlain by granitic rocks. The landuse/cover types delineated for the study area include floodplain (29.27 %), farmland (23.96 %), sparsely vegetated land (15.43 %), built up area (13.65 %), vegetated outcrop (8.48 %), light vegetation (5.37 %), thick vegetation (2.39 %), water body (0.58 %), plantation (0.50 %) and mining pond (0.37 %). Landslide Susceptibility Analysis also revealed that 87 % of the study area is relatively at low to very low risk of landslide event. While only 13 % of the study area is at high to very high risk of landslide event. The study revealed that the susceptibility of landslide event is very low in the study area. However, possible landslide event in the hot spots could be pronounced and could destabilize the natural and man-made environmental systems of the study area.

  15. Landslide: Systematic Dynamic Race Detection in Kernel Space (United States)


    schedule_in_flight← true; CAUSE_TIMER_INTERRUPT(); end if end function Thread Scheduling Finally, the Landslide scheduler is responsible for managing ...child process vanish() simultaneously. • double_wait: Tests interactions of multiple waiters on a single child. • double_thread_fork: Tests for...conditions using Landslide. We describe them here. • Too many waiters allowed. Using the double_wait test case, Group 1 found a bug in which more threads

  16. Urban Landslides Induced by the 2004 Niigata-Chuetsu Earthquake (United States)

    Kamai, T.; Trandafir, A. C.; Sidle, R. C.


    Landslides triggered by the Chuetsu earthquake occurred in artificial slopes of some new developments in suburban Nagaoka, the largest city in the affected area. The landslides occurred in hilly terrain of the eastern part of Nagaoka between the alluvial plain and Tertiary folded mountains of Yamakoshi. Although the extent of landslides in urban Nagaoka was small compared with landslides on natural slopes (especially near Yamakoshi), they represent an important case study for urban landslide disasters. Slope instabilities in urban residential areas were classified as: A) landslides in steep embankments; B) landslides in gently sloping artificial valley fills; C) re-activation of old landslides; and D) liquefaction in deep artificial valley fills. All these failures occurred in relatively uniform suburban landscapes, which were significantly modified from the original landforms. Recent destructive earthquakes in Japan caused similar types of slope failures in urban regions, suggesting that lessons from past earthquakes were not implemented. The greatest damage due to type-A failures occurred in the 25-yr old Takamachi residential area, where about 70 of 522 homes were judged to be uninhabitable. Before development, this area was an isolated hill (90 m elevation) with an adjacent terrace (60 m elevation) consisting of gravel, sand, and silt of the lower to middle Pleistocene deposits. Development earthworks removed the hill crest and created a wide plateau (70 m elevation); excavated soil was placed on the perimeter as an embankment. During the earthquake, the embankment slope collapsed, including retaining walls, perimeter road, and homes. The most serious damage occurred in five places around the margin of the plateau corresponding to shallow valley fills (5 to 8 m thick). Earthquake response analyses using an equivalent linear model indicated the amplification of seismic waves at the surface of embankment slopes, and the peak earthquake acceleration exceeded 1 G


    Directory of Open Access Journals (Sweden)

    T. Bibi


    Full Text Available Landslide is among one of the most important natural hazards that lead to modification of the environment. It is a regular feature of a rapidly growing district Mansehra, Pakistan. This caused extensive loss of life and property in the district located at the foothills of Himalaya. Keeping in view the situation it is concluded that besides structural approaches the non-structural approaches such as hazard and risk assessment maps are effective tools to reduce the intensity of damage. A landslide susceptibility map is base for engineering geologists and geomorphologists. However, it is not easy to produce a reliable susceptibility map due to complex nature of landslides. Since 1980s, several mathematical models have been developed to map landslide susceptibility and hazard. Among various models this paper is discussing the effectiveness of fuzzy logic approach for landslide susceptibility mapping in District Mansehra, Pakistan. The factor maps were modified as landslide susceptibility and fuzzy membership functions were assessed for each class. Likelihood ratios are obtained for each class of contributing factors by considering the expert opinion. The fuzzy operators are applied to generate landslide susceptibility maps. According to this map, 17% of the study area is classified as high susceptibility, 32% as moderate susceptibility, 51% as low susceptibility and areas. From the results it is found that the fuzzy model can integrate effectively with various spatial data for landslide hazard mapping, suggestions in this study are hope to be helpful to improve the applications including interpretation, and integration phases in order to obtain an accurate decision supporting layer.

  18. Relationship between gullying and landslides within the Barlad Plateau, Romania (United States)

    Niacsu, Lilian; Ionita, Ion


    Located in the eastern Romania and extending on 8200 km2 the Barlad Plateau is considered the most typical subunit of the Moldavian Plateau. The sedimentary Miocene-Pliocene clay-sandy layers, inter-bedded with shallow sandstone and limestone are gently dipping toward S-SE as homoclinal structure. Land degradation through soil erosion, gullying and landslides represent the most important environmental threat in the region. By using both the classical research methods such as repeated field surveys and mapping, mathematical-statistical processing as well as the present-day methods based on the GIS software it was possible to precisely measure and evaluate the gully erosion rates and triggered landslides during the last two centuries, especially with a very high accuracy since 1960. Results have indicated that the landslide development is strongly controlled by gullying. Generally, by combining the areal growth of both gullying and new landslides within the selected study catchments, it is noticeable that 62 % of the total recent land degradation occurred during the last 55 years, with the remainder pre-1960. In addition, half of the gully areal growth occurred since 1961 but the new triggered landslides amount over three-quarters of the total area under landslides. This asymmetrical distribution reveals that usually a preparing time lag of tens of years is required for triggering landslides by gullying and this pattern depicts the common mechanism for landslide development. Acknowledgements: This work was partly supported by a grant from the Romanian National Authority for Scientific Research, CNDI-UEFISCDI, Project number PN-II-PT-PCCA-2011-3.2-0975.

  19. Rainfall-induced landslide susceptibility zonation of Puerto Rico (United States)

    Chiara Lepore; Sameer A. Kamal; Peter Shanahan; Rafael L. Bras


    Landslides are a major geologic hazard with estimated tens of deaths and $1–2 billion in economic losses per year in the US alone. The island of Puerto Rico experiences one or two large events per year, often triggered in steeply sloped areas by prolonged and heavy rainfall. Identifying areas susceptible to landslides thus has great potential value for Puerto Rico and...

  20. From Physical Process to Economic Cost - Integrated Approaches of Landslide Risk Assessment (United States)

    Klose, M.; Damm, B.


    The nature of landslides is complex in many respects, with landslide hazard and impact being dependent on a variety of factors. This obviously requires an integrated assessment for fundamental understanding of landslide risk. Integrated risk assessment, according to the approach presented in this contribution, implies combining prediction of future landslide occurrence with analysis of landslide impact in the past. A critical step for assessing landslide risk in integrated perspective is to analyze what types of landslide damage affected people and property in which way and how people contributed and responded to these damage types. In integrated risk assessment, the focus is on systematic identification and monetization of landslide damage, and analytical tools that allow deriving economic costs from physical landslide processes are at the heart of this approach. The broad spectrum of landslide types and process mechanisms as well as nonlinearity between landslide magnitude, damage intensity, and direct costs are some main factors explaining recent challenges in risk assessment. The two prevailing approaches for assessing the impact of landslides in economic terms are cost survey (ex-post) and risk analysis (ex-ante). Both approaches are able to complement each other, but yet a combination of them has not been realized so far. It is common practice today to derive landslide risk without considering landslide process-based cause-effect relationships, since integrated concepts or new modeling tools expanding conventional methods are still widely missing. The approach introduced in this contribution is based on a systematic framework that combines cost survey and GIS-based tools for hazard or cost modeling with methods to assess interactions between land use practices and landslides in historical perspective. Fundamental understanding of landslide risk also requires knowledge about the economic and fiscal relevance of landslide losses, wherefore analysis of their

  1. Sustainable development in the Hudson Bay/James Bay bioregion

    International Nuclear Information System (INIS)



    An overview is presented of projects planned for the James Bay/Hudson Bay region, and the expected environmental impacts of these projects. The watershed of James Bay and Hudson Bay covers well over one third of Canada, from southern Alberta to central Ontario to Baffin Island, as well as parts of north Dakota and Minnesota in the U.S.A. Hydroelectric power developments that change the timing and rate of flow of fresh water may cause changes in the nature and duration of ice cover, habitats of marine mammals, fish and migratory birds, currents into and out of Hudson Bay/James Bay, seasonal and annual loads of sediments and nutrients to marine ecosystems, and anadromous fish populations. Hydroelectric projects are proposed for the region by Quebec, Ontario and Manitoba. In January 1992, the Canadian Arctic Resources Committee (CARC), the Environmental Committee of Sanikuluaq, and the Rawson Academy of Arctic Science will launch the Hudson Bay/James Bay Bioregion Program, an independent initiative to apply an ecosystem approach to the region. Two main objectives are to provide a comprehensive assessment of the cumulative impacts of human activities on the marine and freshwater ecosystems of the Hudson Bay/James Bay bioregion, and to foster sustainable development by examining and proposing cooperative processes for decision making among governments, developers, aboriginal peoples and other stakeholders. 1 fig

  2. Regional Landslide Hazard Assessment Considering Potential Climate Change (United States)

    Almeida, S.; Holcombe, E.; Pianosi, F.; Wagener, T.


    Landslides have many negative economic and societal impacts, including the potential for significant loss of life and damage to infrastructure. These risks are likely to be exacerbated in the future by a combination of climatic and socio-economic factors. Climate change, for example, is expected to increase the occurrence of rainfall-triggered landslides, because a warmer atmosphere tends to produce more high intensity rainfall events. Prediction of future changes in rainfall, however, is subject to high levels of uncertainty, making it challenging for decision-makers to identify the areas and populations that are most vulnerable to landslide hazards. In this study, we demonstrate how a physically-based model - the Combined Hydrology and Stability Model (CHASM) - can be used together with Global Sensitivity Analysis (GSA) to explore the underlying factors controlling the spatial distribution of landslide risks across a regional landscape, while also accounting for deep uncertainty around potential future rainfall triggers. We demonstrate how GSA can be used to analyse CHASM which in turn represents the spatial variability of hillslope characteristics in the study region, while accounting for other uncertainties. Results are presented in the form of landslide hazard maps, utilising high-resolution digital elevation datasets for a case study in St Lucia in the Caribbean. Our findings about spatial landslide hazard drivers have important implications for data collection approaches and for long-term decision-making about land management practices.

  3. Regional landslide hazard assessment in a deep uncertain future (United States)

    Almeida, Susana; Holcombe, Liz; Pianosi, Francesca; Wagener, Thorsten


    Landslides have many negative economic and societal impacts, including the potential for significant loss of life and damage to infrastructure. These risks are likely to be exacerbated in the future by a combination of climatic and socio-economic factors. Climate change, for example, is expected to increase the occurrence of rainfall-triggered landslides, because a warmer atmosphere tends to produce more high intensity rainfall events. Prediction of future changes in rainfall, however, is subject to high levels of uncertainty, making it challenging for decision-makers to identify the areas and populations that are most vulnerable to landslide hazards. In this study, we demonstrate how a physically-based model - the Combined Hydrology and Stability Model (CHASM) - can be used together with Global Sensitivity Analysis (GSA) to explore the underlying factors controlling the spatial distribution of landslide risks across a regional landscape, while also accounting for deep uncertainty around future rainfall conditions. We demonstrate how GSA can used to analyse CHASM which in turn represents the spatial variability of hillslope characteristics in the study region, while accounting for other uncertainties. Results are presented in the form of landslide hazard maps, utilising high-resolution digital elevation datasets for a case study in St Lucia in the Caribbean. Our findings about spatial landslide hazard drivers have important implications for data collection approaches and for long-term decision-making about land management practices.

  4. Multi - band Persistent Scatterer Interferometry data integration for landslide analysis (United States)

    Bianchini, Silvia; Mateos, Rosa; Mora, Oscar; García, Inma; Sánchez, Ciscu; Sanabria, Margarita; López, Maite; Mulas, Joaquin; Hernández, Mario; Herrera, Gerardo


    We present a methodology to perform a geomorphological assessment of ground movements over wide areas, by improving Persistent Scatterer Interferometry (PSI) analysis for landslide studies. The procedure relies on the integrated use of multi-band EO data acquired by different satellite sensors in different time intervals, to provide a detailed investigation of ground displacements. The methodology, throughout the cross-comparison and integration of PS data in different microwave bands (ALOS in L-band, ERS1/2 and ENVISAT in C-band, COSMOSKY-MED in X-band), is applied on the Tramontana Range in the northwestern part of Mallorca island (Spain), extensively affected by mass movements across time, especially during the last years. We increase the confidence degree of the available interferometric data and we homogenize all PS targets by implementing and classifying them through common criteria. Therefore, PSI results are combined with geo-thematic data and pre-existing landslide inventories of the study area, in order to improve the landslide database, providing additional information on the detected ground displacements. The results of this methodology are used to elaborate landslide activity maps, permitting to jointly exploit heterogeneous PS data for analyzing landslides at regional scale. Moreover, from a geomorphological perspective, the proposed approach exploits the implemented PS data to achieve a reliable spatial analysis of movement rates, whatever referred to certain landslide phenomena or to other natural processes, in order to perform ground motion activity maps within a wide area.


    Directory of Open Access Journals (Sweden)

    Mariana Madruga de Brito


    Full Text Available This paper presents the application of a multi-criteria analysis (MCA tool for landslide susceptibility assessment in Porto Alegre municipality, southern Brazil. A knowledge driven approach was used, aiming to ensure an optimal use of the available information. The landslide conditioning factors considered were slope, lithology, flow accumulation and distance from lineaments. Standardization of these factors was done through fuzzy membership functions, and evaluation of their relative importance for landslide predisposition was supported by the analytic hierarchy process (AHP, based on local expert knowledge. Finally, factors were integrated in a GIS environment using the weighted linear combination (WLC method. For validation, an inventory, including 107 landslide points recorded between 2007 and 2013 was used. Results indicated that 8.2% (39.40 km² of the study area are highly and very highly susceptible to landslides. An overall accuracy of 95% was found, with an area under the receiver operating characteristic (ROC curve of 0.960. Therefore, the resulting map can be regarded as useful for monitoring landslide-prone areas. Based on the findings, it is concluded that the proposed method is effective for susceptibility assessment since it yielded meaningful results and does not require extensive input data.

  6. Effects of Inventory Bias on Landslide Susceptibility Calculations (United States)

    Stanley, T. A.; Kirschbaum, D. B.


    Many landslide inventories are known to be biased, especially inventories for large regions such as Oregon's SLIDO or NASA's Global Landslide Catalog. These biases must affect the results of empirically derived susceptibility models to some degree. We evaluated the strength of the susceptibility model distortion from postulated biases by truncating an unbiased inventory. We generated a synthetic inventory from an existing landslide susceptibility map of Oregon, then removed landslides from this inventory to simulate the effects of reporting biases likely to affect inventories in this region, namely population and infrastructure effects. Logistic regression models were fitted to the modified inventories. Then the process of biasing a susceptibility model was repeated with SLIDO data. We evaluated each susceptibility model with qualitative and quantitative methods. Results suggest that the effects of landslide inventory bias on empirical models should not be ignored, even if those models are, in some cases, useful. We suggest fitting models in well-documented areas and extrapolating across the study region as a possible approach to modeling landslide susceptibility with heavily biased inventories.

  7. InSAR deformation monitoring of high risk landslides (United States)

    Singhroy, V.; Li, J.


    During the past year there were at least twenty five media reports of landslides and seismic activities some fatal, occurring in various areas in Canada. These high risk geohazards sites requires high resolution monitoring both spatially and temporally for mitigation purposes, since they are near populated areas and energy, transportation and communication corridors. High resolution air photos, lidar and satellite images are quite common in areas where the landslides can be fatal. Radar interferometry (InSAR) techniques using images from several radar satellites are increasingly being used in slope stability assessment. This presentation provides examples of using high-resolution (1-3m) frequent revisits InSAR techniques from RADARSAT 2 and TerraSAR X to monitor several types of high-risk landslides affecting transportation and energy corridors and populated areas. We have analyses over 200 high resolution InSAR images over a three year period on geologically different landslides. The high-resolution InSAR images are effective in characterizing differential motion within these low velocity landslides. The low velocity landslides become high risk during the active wet spring periods. The wet soils are poor coherent targets and corner reflectors provide an effective means of InSAR monitoring the slope activities.

  8. Landslide movement in southwest Colorado triggered by atmospheric tides (United States)

    Schulz, W.H.; Kean, J.W.; Wang, G.


    Landslides are among the most hazardous of geological processes, causing thousands of casualties and damage on the order of billions of dollars annually. The movement of most landslides occurs along a discrete shear surface, and is triggered by a reduction in the frictional strength of the surface. Infiltration of water into the landslide from rainfall and snowmelt and ground motion from earthquakes are generally implicated in lowering the frictional strength of this surface. However, solid-Earth and ocean tides have recently been shown to trigger shear sliding in other processes, such as earthquakes and glacial motion. Here we use observations and numerical modelling to show that a similar processatmospheric tidescan trigger movement in an ongoing landslide. The Slumgullion landslide, located in the SanJuan Mountains of Colorado, shows daily movement, primarily during diurnal low tides of the atmosphere. According to our model, the tidal changes in air pressure cause air and water in the sediment pores to flow vertically, altering the frictional stress of the shear surface; upward fluid flow during periods of atmospheric low pressure is most conducive to sliding. We suggest that tidally modulated changes in shear strength may also affect the stability of other landslides, and that the rapid pressure variations associated with some fast-moving storm systems could trigger a similar response. ?? 2009 Macmillan Publishers Limited. All rights reserved.

  9. Remote landslide mapping using a laser rangefinder binocular and GPS

    Directory of Open Access Journals (Sweden)

    M. Santangelo


    Full Text Available We tested a high-quality laser rangefinder binocular coupled with a GPS receiver connected to a Tablet PC running dedicated software to help recognize and map in the field recent rainfall-induced landslides. The system was tested in the period between March and April 2010, in the Monte Castello di Vibio area, Umbria, Central Italy. To test the equipment, we measured thirteen slope failures that were mapped previously during a visual reconnaissance field campaign conducted in February and March 2010. For reference, four slope failures were also mapped by walking the GPS receiver along the landslide perimeter. Comparison of the different mappings revealed that the geographical information obtained remotely for each landslide by the rangefinder binocular and GPS was comparable to the information obtained by walking the GPS around the landslide perimeter, and was superior to the information obtained through the visual reconnaissance mapping. Although our tests were not exhaustive, we maintain that the system is effective to map recent rainfall induced landslides in the field, and we foresee the possibility of using the same (or similar system to map landslides, and other geomorphological features, in other areas.

  10. Landslide Hazard Assessment and Mapping in the Guil Catchment (Queyras, Southern French Alps): From Landslide Inventory to Susceptibility Modelling (United States)

    Roulleau, Louise; Bétard, François; Carlier, Benoît; Lissak, Candide; Fort, Monique


    Landslides are common natural hazards in the Southern French Alps, where they may affect human lives and cause severe damages to infrastructures. As a part of the SAMCO research project dedicated to risk evaluation in mountain areas, this study focuses on the Guil river catchment (317 km2), Queyras, to assess landslide hazard poorly studied until now. In that area, landslides are mainly occasional, low amplitude phenomena, with limited direct impacts when compared to other hazards such as floods or snow avalanches. However, when interacting with floods during extreme rainfall events, landslides may have indirect consequences of greater importance because of strong hillslope-channel connectivity along the Guil River and its tributaries (i.e. positive feedbacks). This specific morphodynamic functioning reinforces the need to have a better understanding of landslide hazards and their spatial distribution at the catchment scale to prevent local population from disasters with multi-hazard origin. The aim of this study is to produce a landslide susceptibility mapping at 1:50 000 scale as a first step towards global estimation of landslide hazard and risk. The three main methodologies used for assessing landslide susceptibility are qualitative (i.e. expert opinion), deterministic (i.e. physics-based models) and statistical methods (i.e. probabilistic models). Due to the rapid development of geographical information systems (GIS) during the last two decades, statistical methods are today widely used because they offer a greater objectivity and reproducibility at large scales. Among them, multivariate analyses are considered as the most robust techniques, especially the logistic regression method commonly used in landslide susceptibility mapping. However, this method like others is strongly dependent on the accuracy of the input data to avoid significant errors in the final results. In particular, a complete and accurate landslide inventory is required before the modelling

  11. Landslide risk reduction strategies: an inventory for the Global South (United States)

    Maes, Jan; Kervyn, Matthieu; Vranken, Liesbet; Dewitte, Olivier; Vanmaercke, Matthias; Mertens, Kewan; Jacobs, Liesbet; Poesen, Jean


    Landslides constitute a serious problem globally. Moreover, landslide impact remains underestimated especially in the Global South. It is precisely there where the largest impact is experienced. An overview of measures taken to reduce risk of landslides in the Global South is however still lacking. Because in many countries of the Global South disaster risk reduction (DRR) is at an emerging stage, it is crucial to monitor the ongoing efforts (e.g. discussions on the Post-2015 Framework for DRR). The first objective of this study is to make an inventory of techniques and strategies that are applied to reduce risk from landslides in tropical countries. The second objective is to investigate what are the main bottlenecks for implementation of DRR strategies. In order to achieve these objectives, a review of both scientific and grey literature was conducted, supplemented with expert knowledge. The compilation of recommended and implemented DRR measures from landslide-prone tropical countries is based on an adapted classification proposed by the SafeLand project. According to Vaciago (2013), landslide risk can be reduced by either reducing the hazard, the vulnerability, the number or value of elements at risk or by sharing the residual risk. In addition, these measures can be combined with education and/or awareness raising and are influenced by governance structures and cultural beliefs. Global landslide datasets have been used to identify landslide-prone countries, augmented with region-specific datasets. Countries located in the tropics were selected in order to include landslide-prone countries with a different Human Development Index (HDI) but with a similar climate. Preliminary results support the statement made by Anderson (2013) that although the importance of shifting from post-disaster emergency actions to pre-disaster mitigation is acknowledged, in practice this paradigm shift seems rather limited. It is expected that this is especially the case in countries

  12. Landsliding and sediment flux in the Central Swiss Alps: A photogrammetric study of the Schimbrig landslide, Entlebuch (United States)

    Schwab, Marco; Rieke-Zapp, Dirk; Schneider, Heinz; Liniger, Markus; Schlunegger, Fritz


    This study explores the effects of hillslope mass failure on the sediment flux in the Waldemme drainage basin, Central Swiss Alps, over decadal time scales. This area is characterized by abundant landslides affecting principally flysch units and is therefore an important sediment source. The analysis concentrates on the Schimbrig landslide that potentially contributes up to 15% to the sediment budget of the Waldemme drainage basin. Volumetric changes are quantified using high-resolution elevation models that were extracted using digital photogrammetric techniques. Sediment discharge data were used to constrain the significance of the landslide for sediment flux in the channel network. The temporal extent of the photogrammetric analysis ranges from 1962 to 1998, including an earth slide event in 1994. The analyses reveal that during periods of low slip rates of the landslide, nearly all of the displaced sediments were eroded and supplied to the channel network. In contrast, during active periods, only a fraction of the displaced landslide mass was exported to the trunk stream. Interestingly, the 1994 earth slide event did not disturb the long-term sediment discharge pattern of the channel network, nor did it influence the sediment flux at a weekly scale. However, suspended sediment pulses correlate with higher-than-average precipitation events. This was especially the case in August 2005 when a storm event (> 100 years return period) triggered several debris flows and earth flows in the whole drainage basin and in the Schimbrig area. This storm did not result in a significant increase in the slip rates of the entire landslide's main body. It is therefore proposed that debris flows and earth flows perform the connectivity between hillslope processes (e.g. landsliding) and the trunk stream during and between phases of landslide activity in this particular setting.

  13. Building rainfall thresholds for large-scales landslides by extracting occurrence time of landslides from seismic records (United States)

    Yen, Hsin-Yi; Lin, Guan-Wei


    Understanding the rainfall condition which triggers mass moment on hillslope is the key to forecast rainfall-induced slope hazards, and the exact time of landslide occurrence is one of the basic information for rainfall statistics. In the study, we focused on large-scale landslides (LSLs) with disturbed area larger than 10 ha and conducted a string of studies including the recognition of landslide-induced ground motions and the analyses of different terms of rainfall thresholds. More than 10 heavy typhoons during the periods of 2005-2014 in Taiwan induced more than hundreds of LSLs and provided the opportunity to characterize the rainfall conditions which trigger LSLs. A total of 101 landslide-induced seismic signals were identified from the records of Taiwan seismic network. These signals exposed the occurrence time of landslide to assess rainfall conditions. Rainfall analyses showed that LSLs occurred when cumulative rainfall exceeded 500 mm. The results of rainfall-threshold analyses revealed that it is difficult to distinct LSLs from small-scale landslides (SSLs) by the I-D and R-D methods, but the I-R method can achieve the discrimination. Besides, an enhanced three-factor threshold considering deep water content was proposed as the rainfall threshold for LSLs.

  14. Sentinel-2 for rapid operational landslide inventory mapping (United States)

    Stumpf, André; Marc, Odin; Malet, Jean-Philippe; Michea, David


    Landslide inventory mapping after major triggering events such as heavy rainfalls or earthquakes is crucial for disaster response, the assessment of hazards, and the quantification of sediment budgets and empirical scaling laws. Numerous studies have already demonstrated the utility of very-high resolution satellite and aerial images for the elaboration of inventories based on semi-automatic methods or visual image interpretation. Nevertheless, such semi-automatic methods are rarely used in an operational context after major triggering events; this is partly due to access limitations on the required input datasets (i.e. VHR satellite images) and to the absence of dedicated services (i.e. processing chain) available for the landslide community. Several on-going initiatives allow to overcome these limitations. First, from a data perspective, the launch of the Sentinel-2 mission offers opportunities for the design of an operational service that can be deployed for landslide inventory mapping at any time and everywhere on the globe. Second, from an implementation perspective, the Geohazards Exploitation Platform (GEP) of the European Space Agency (ESA) allows the integration and diffusion of on-line processing algorithms in a high computing performance environment. Third, from a community perspective, the recently launched Landslide Pilot of the Committee on Earth Observation Satellites (CEOS), has targeted the take-off of such service as a main objective for the landslide community. Within this context, this study targets the development of a largely automatic, supervised image processing chain for landslide inventory mapping from bi-temporal (before and after a given event) Sentinel-2 optical images. The processing chain combines change detection methods, image segmentation, higher-level image features (e.g. texture, shape) and topographic variables. Based on a few representative examples provided by a human operator, a machine learning model is trained and

  15. Kinematic analysis for the implementation of landslide mitigation measures (United States)

    Delmonaco, Giuseppe; Margottini, Claudio; Spizzichino, Daniele


    The present work is finalised at the implementation of a landslide risk mitigation master plan of the ancient citadel of Machu Picchu. After the warning launched in March 2001, by the scientific community on potential collapse of the citadel from a near-disastrous landslide event different studies have been promoted to reconstruct landslide activity and suggest landslide risk mitigation measures for the protection and conservation of Machu Picchu cultural heritage. A site-scale analysis has been implemented following the application and integration of geomechanical classifications, ambient noise measurements and structural and kinematical analysis. The geology of the area is characterized by granitoid bodies that had been emplaced in the axial zones of the main rift system that are now exposed at the highest altitudes, together with country rocks (Precambrian and Lower Paleozoic metamorphics) originally constituting the rift ‘roots'. The bedrock of the Inca citadel of Machu Picchu is mainly composed by granite and subordinately granodiorite. This is mainly located in the lower part of the slopes. Superficially, the granite is jointed in blocks with variable dimensions, promoted by local structural setting. Single blocks vary from 10-1 to about 200 m3. Soil cover, widely outcropping in the area, is mainly composed by individual blocks and subordinately by coarse materials originated by chemical and physical weathering of minerals. Regional tectonic uplift and structural setting rule the general morphological features of the area and as a consequence, landslide type and evolution. Rock falls, rock slides, debris flows and debris slides are the main landslide typologies affecting the citadel slopes. In the last mission in May 2009, elastic and deformation rock parameters have been collected using a passive seismic innovative technique based on natural microtremor measurements and geostructural scan lines elaboration. A landslide zoning of the citadel has been

  16. Long term monitoring of landslide: observation gravitational slope cycles (United States)

    Palis, Edouard; Lebourg, Thomas; Vidal, Maurin


    Since several years of studies on landslides, we realized the role and subtle interactions that existed between the structural complexity, masses dynamics and complex internal circulation of fluids. Thus, to gain a better understanding of the processes taking place during the evolution of an unstable slope, an observational study is necessary. In this perspective, our team currently monitors slow moving landslide zones. The aim of such a monitoring is to gain a better knowledge of the links between external forcing (meteorological, seismological) and signals going out of the slope (kinematic, vibrations, electrical resistivity). In December 2000, a dramatic event affected the sandy/clayey landslide in the Southern Alpes Maritimes (France). A 10 meters high scarp appeared at the foot of the landslide and affected private yards nearby. This area then became a major concern for local authorities and understand the processes taking place, a scientific challenge. In order to understand the land-sliding reactivations and to quantify the natural cycles of deformations, we analyse the main factors of this complex system. After 10 years of observation we are now able to highlight some of the complex behaviours by the measurement of physical parameters (geophysical monitoring). A permanent 115 m ERT line (5 meters electrode spacing) has been installed and provides an acquisition daily since 2006. The daily acquisitions are now accompanied by continuous measurements from boreholes (thermometers, piezometers, tiltmeters) and pluviometry. We are able to control the whole monitoring from the lab, and all these data are transmitted in real time. The analysis of these large amounts of data over large time series allows the detection of seasonal cycles of surface activity. The deformation taking place can be assimilated to a near-elastic deformation and show a lateral decoupling on both sides of the fault cutting the landslide. These deformation cycles can be associated with the

  17. Filling, storing and draining. Three key aspects of landslide hydrology (United States)

    Bogaard, Thom; Greco, Roberto


    Rainfall-triggered landslides are among the most widespread hazards in the world. The hydrology in and around a landslide area is key to pore pressure build-up in the soil skeleton which reduces shear strength due to the buoyancy force exerted by water in a saturated soil and to soil suction in an unsaturated soil. Extraordinary precipitation events trigger most of the landslides, but, at the same time, the vast majority of slopes do not fail. The intriguing question is: 'When and where exactly can a slope become triggered to slide and flow downwards?' The objective of this article is to present and discuss landslide hydrology at three scales - pore, hillslope, and catchment - which, taken together, give an overview of this interdisciplinary science. In fact, for rainfall-triggered landslides to occur, an unfavourable hydrological interplay should exist between fast and/or prolonged infiltration, and a relatively 'slow' drainage. The competition of water storage, pressure build-up and the subsequently induced drainage contains the importance of the timing, which is indisputably one of the more delicate but relevant aspects of landslide modelling, the overlay of hydrological processes with different time scales. As slopes generally remain stable, we can argue that effective drainage mechanisms spontaneously develop, as the best for a slope to stay stable is getting rid of the overload of water (above field capacity), either vertically or laterally. So, landslide hydrology could be framed as 'Filling-Storing-Draining'. Obviously, 'Storing' is added to stress the importance of dynamic pressure build-up for slope stability. 'Draining' includes all removal of water from the system (vertical and lateral flow, evaporation and transpiration) and thus pore water pressure release. Furthermore, by addressing landslide hydrology from both earth sciences and soil mechanics perspectives, we aim to manifest the hydrological processes in hillslopes and their influence on behaviour

  18. Derivation of critical rainfall thresholds for landslide in Sicily (United States)

    Caracciolo, Domenico; Arnone, Elisa; Noto, Leonardo V.


    Rainfall is the primary trigger of shallow landslides that can cause fatalities, damage to properties and economic losses in many areas of the world. For this reason, determining the rainfall amount/intensity responsible for landslide occurrence is important, and may contribute to mitigate the related risk and save lives. Efforts have been made in different countries to investigate triggering conditions in order to define landslide-triggering rainfall thresholds. The rainfall thresholds are generally described by a functional relationship of power in terms of cumulated or intensity event rainfall-duration, whose parameters are estimated empirically from the analysis of historical rainfall events that triggered landslides. The aim of this paper is the derivation of critical rainfall thresholds for landslide occurrence in Sicily, southern Italy, by focusing particularly on the role of the antecedent wet conditions. The creation of the appropriate landslide-rainfall database likely represents one of main efforts in this type of analysis. For this work, historical landslide events occurred in Sicily from 1919 to 2001 were selected from the archive of the Sistema Informativo sulle Catastrofi Idrogeologiche, developed under the project Aree Vulnerabili Italiane. The corresponding triggering precipitations were screened from the raingauges network in Sicily, maintained by the Osservatorio delle Acque - Agenzia Regionale per i Rifiuti e le Acque. In particular, a detailed analysis was carried out to identify and reconstruct the hourly rainfall events that caused the selected landslides. A bootstrapping statistical technique has been used to determine the uncertainties associated with the threshold parameters. The rainfall thresholds at different exceedance probability levels, from 1% to 10%, were defined in terms of cumulated event rainfall, E, and rainfall duration, D. The role of rainfall prior to the damaging events was taken into account by including in the analysis

  19. Weights of Evidence Method for Landslide Susceptibility Mapping in Takengon, Central Aceh, Indonesia (United States)

    Pamela; Sadisun, Imam A.; Arifianti, Yukni


    Takengon is an area prone to earthquake disaster and landslide. On July 2, 2013, Central Aceh earthquake induced large numbers of landslides in Takengon area, which resulted in casualties of 39 people. This location was chosen to assess the landslide susceptibility of Takengon, using a statistical method, referred to as the weight of evidence (WoE). This WoE model was applied to indicate the main factors influencing the landslide susceptible area and to derive landslide susceptibility map of Takengon. The 251 landslides randomly divided into two groups of modeling/training data (70%) and validation/test data sets (30%). Twelve thematic maps of evidence are slope degree, slope aspect, lithology, land cover, elevation, rainfall, lineament, peak ground acceleration, curvature, flow direction, distance to river and roads used as landslide causative factors. According to the AUC, the significant factor controlling the landslide is the slope, the slope aspect, peak ground acceleration, elevation, lithology, flow direction, lineament, and rainfall respectively. Analytical result verified by using test data of landslide shows AUC prediction rate is 0.819 and AUC success rate with all landslide data included is 0.879. This result showed the selective factors and WoE method as good models for assessing landslide susceptibility. The landslide susceptibility map of Takengon shows the probabilities, which represent relative degrees of susceptibility for landslide proneness in Takengon area.

  20. Shallow Landslide Susceptibility Modeling Using the Data Mining Models Artificial Neural Network and Boosted Tree

    Directory of Open Access Journals (Sweden)

    Hyun-Joo Oh


    Full Text Available The main purpose of this paper is to present some potential applications of sophisticated data mining techniques, such as artificial neural network (ANN and boosted tree (BT, for landslide susceptibility modeling in the Yongin area, Korea. Initially, landslide inventory was detected from visual interpretation using digital aerial photographic maps with a high resolution of 50 cm taken before and after the occurrence of landslides. The debris flows were randomly divided into two groups: training and validation sets with a 50:50 proportion. Additionally, 18 environmental factors related to landslide occurrence were derived from the topography, soil, and forest maps. Subsequently, the data mining techniques were applied to identify the influence of environmental factors on landslide occurrence of the training set and assess landslide susceptibility. Finally, the landslide susceptibility indexes from ANN and BT were compared with a validation set using a receiver operating characteristics curve. The slope gradient, topographic wetness index, and timber age appear to be important factors in landslide occurrence from both models. The validation result of ANN and BT showed 82.25% and 90.79%, which had reasonably good performance. The study shows the benefit of selecting optimal data mining techniques in landslide susceptibility modeling. This approach could be used as a guideline for choosing environmental factors on landslide occurrence and add influencing factors into landslide monitoring systems. Furthermore, this method can rank landslide susceptibility in urban areas, thus providing helpful information when selecting a landslide monitoring site and planning land-use.

  1. Spatio-Temporal Distribution of Landslides in Java and the Triggering Factors

    Directory of Open Access Journals (Sweden)

    Danang Sri Hadmoko


    Full Text Available Java Island, the most populated island of Indonesia, is prone to landslide disasters. Their occurrence and impact have increased mainly as the result of natural factors, aggravated by human imprint. This paper is intended to analyse: (1 the spatio-temporal variation of landslides in Java during short term and long-term periods, and (2 their causative factors such as rainfall, topography, geology, earthquakes, and land-use. The evaluation spatially and temporally of historical landslides and consequences were based on the landslide database covering the period of 1981 – 2007 in the GIS environment. Database showed that landslides distributed unevenly between West Java (67 %, Central Java (29 % and East Java (4 %. Slope failures were most abundant on the very intensively weathered zone of old volcanic materials on slope angles of 30O – 40O. Rainfall threshold analysis showed that shallow landslides and deep-seated landslides were triggered by rainfall events of 300 – 600 mm and > 600 mm respectively of antecedent rainfall during 30 consecutive days, and many cases showed that the landslides were not always initiated by intense rainfall during the landslide day. Human interference plays an important role in landslide occurrence through land conversion from natural forest to dryland agriculture which was the host of most of landslides in Java. These results and methods can be used as valuable information on the spatio-temporal characteristics of landslides in Java and their relationship with causative factors, thereby providing a sound basis for landslide investigation in more detail.

  2. Soil characteristics of landslides on Mount Elgon (Uganda): implications for estimating their age (United States)

    Van Eynde, Elise; Dondeyne, Stefaan; Isabirye, Moses; Deckers, Jozef; Poesen, Jean


    The slopes of Mount Elgon, a complex volcano at the border between Uganda and Kenya, are frequently affected by landslides with disastrous effects on the livelihood of its population. Since local people greatly depend on the land for crop production, we examined if and how fast physico-chemical characteristics in landslide scars recover. A chronosequence of 18 landslides covering a period of 103 years was sampled in order to explore differences between topsoil within and outside landslide scars. For each landslide, two topsoil samples were taken within the landslide and two in nearby undisturbed soils to compare their physico-chemical characteristics. No differences were found for available P, Ca2+, Mg2+ content or for the fine earth texture. Recent landslides had however lower content of soil organic carbon (OC) and K+, and higher content of rock fragments and Na+ than the adjacent soils. Soil OC content increased significantly with age and reached levels of the corresponding undisturbed soils after ca. 60 years. Older landslides had even higher OC contents than soils adjacent to the landslide. Hence landslide scars act as local carbon sink. We suggest that the occurrence of rock fragments in the topsoil is a useful indicator for mapping past landslides. Moreover, the difference in soil OC content between landslide scars and adjacent soil could be used for estimating the age of landslides in data-poor regions.

  3. Landslides and megathrust splay faults captured by the late Holocene sediment record of eastern Prince William Sound, Alaska (United States)

    Finn, S.P.; Liberty, Lee M.; Haeussler, Peter J.; Pratt, Thomas L.


    We present new marine seismic‐reflection profiles and bathymetric maps to characterize Holocene depositional patterns, submarine landslides, and active faults beneath eastern and central Prince William Sound (PWS), Alaska, which is the eastern rupture patch of the 1964 Mw 9.2 earthquake. We show evidence that submarine landslides, many of which are likely earthquake triggered, repeatedly released along the southern margin of Orca Bay in eastern PWS. We document motion on reverse faults during the 1964 Great Alaska earthquake and estimate late Holocene slip rates for these growth faults, which splay from the subduction zone megathrust. Regional bathymetric lineations help define the faults that extend 40–70 km in length, some of which show slip rates as great as 3.75  mm/yr. We infer that faults mapped below eastern PWS connect to faults mapped beneath central PWS and possibly onto the Alaska mainland via an en echelon style of faulting. Moderate (Mw>4) upper‐plate earthquakes since 1964 give rise to the possibility that these faults may rupture independently to potentially generate Mw 7–8 earthquakes, and that these earthquakes could damage local infrastructure from ground shaking. Submarine landslides, regardless of the source of initiation, could generate local tsunamis to produce large run‐ups along nearby shorelines. In a more general sense, the PWS area shows that faults that splay from the underlying plate boundary present proximal, perhaps independent seismic sources within the accretionary prism, creating a broad zone of potential surface rupture that can extend inland 150 km or more from subduction zone trenches.

  4. Comparison and Evolution of Extreme Rainfall-Induced Landslides in Taiwan

    Directory of Open Access Journals (Sweden)

    Chunhung WU


    Full Text Available This study analyzed the characteristics of, and locations prone to, extreme rainfall-induced landslides in three watersheds in Taiwan, as well as the long-term evolution of landslides in the Laonong River watershed (LRW, based on multiannual landslide inventories during 2003–2014. Extreme rainfall-induced landslides were centralized beside sinuous or meandering reaches, especially those with large sediment deposition. Landslide-prone strata during extreme rainfall events were sandstone and siltstone. Large-scale landslides were likely to occur when the maximum 6-h accumulated rainfall exceeded 420 mm. All of the large-scale landslides induced by short-duration and high-intensity rainfall developed from historical small-scale landslides beside the sinuous or meandering reaches or in the source area of rivers. However, most of the large-scale landslides induced by long-duration and high-intensity rainfall were new but were still located beside sinuous or meandering reaches or near the source. The frequency density of landslides under long-duration and high-intensity rainfall was larger by one order than those under short-duration rainfall, and the β values in the landslide frequency density-area analysis ranged from 1.22 to 1.348. The number of downslope landslides was three times larger than those of midslope and upslope landslides. The extreme rainfall-induced landslides occurred in the erosion gullies upstream of the watersheds, whereas those beside rivers were downstream. Analysis of the long-term evolution of landslides in the LRW showed that the geological setting, sinuousness of reaches, and sediment yield volume determined their location and evolution. Small-scale landslides constituted 71.9–96.2% of the total cases from 2003 to 2014, and were more easily induced after Typhoon Morakot (2009. The frequency density of landslides after Morakot was greater by one order than before, with 61% to 68% of total landslides located in the

  5. Assessment of Rainfall-induced Landslide Potential and Spatial Distribution (United States)

    Chen, Yie-Ruey; Tsai, Kuang-Jung; Chen, Jing-Wen; Chiang, Jie-Lun; Hsieh, Shun-Chieh; Chue, Yung-Sheng


    Recently, due to the global climate change, most of the time the rainfall in Taiwan is of short duration but with high intensity. Due to Taiwan's steep terrain, rainfall-induced landslides often occur and lead to human causalities and properties loss. Taiwan's government has invested huge reconstruction funds to the affected areas. However, after rehabilitation they still face the risk of secondary sediment disasters. Therefore, this study assesses rainfall-induced (secondary) landslide potential and spatial distribution in watershed of Southern Taiwan under extreme climate change. The study areas in this research are Baolai and Jianshan villages in the watershed of the Laonongxi River Basin in the Southern Taiwan. This study focused on the 3 years after Typhoon Morakot (2009 to 2011). During this period, the study area experienced six heavy rainfall events including five typhoons and one heavy rainfall. The genetic adaptive neural network, texture analysis and GIS were implemented in the analysis techniques for the interpretation of satellite images and to obtain surface information and hazard log data and to analyze land use change. A multivariate hazards evaluation method was applied to quantitatively analyze the weights of various natural environmental and slope development hazard factors. Furthermore, this study established a slope landslide potential assessment model and depicted a slope landslide potential diagram by using the GIS platform. The interaction between (secondary) landslide mechanism, scale, and location was analyzed using association analysis of landslide historical data and regional environmental characteristics. The results of image classification before and after six heavy rainfall events show that the values of coefficient of agreement are at medium-high level. By multivariate hazards evaluation method, geology and the effective accumulative rainfall (EAR) are the most important factors. Slope, distance from fault, aspect, land disturbance

  6. Object-based landslide detection in different geographic regions (United States)

    Friedl, Barbara; Hölbling, Daniel; Eisank, Clemens; Blaschke, Thomas


    Landslides occur in almost all mountainous regions of the world and rank among the most severe natural hazards. In the last decade - according to the world disaster report 2014 published by the International Federation of Red Cross and Red Crescent Societies (IRFC) - more than 9.000 people were killed by mass movements, more than 3.2 million people were affected and the total amount of disaster estimated damage accounts to more than 1.700 million US dollars. The application of remote sensing data for mapping landslides can contribute to post-disaster reconstruction or hazard mitigation, either by providing rapid information about the spatial distribution and location of landslides in the aftermath of triggering events or by creating and updating landslide inventories. This is especially valid for remote and inaccessible areas, where information on landslides is often lacking. However, reliable methods are needed for extracting timely and relevant information about landslides from remote sensing data. In recent years, novel methods such as object-based image analysis (OBIA) have been successfully employed for semi-automated landslide mapping. Several studies revealed that OBIA frequently outperforms pixel-based approaches, as a range of image object properties (spectral, spatial, morphometric, contextual) can be exploited during the analysis. However, object-based methods are often tailored to specific study areas, and thus, the transferability to regions with different geological settings, is often limited. The present case study evaluates the transferability and applicability of an OBIA approach for landslide detection in two distinct regions, i.e. the island of Taiwan and Austria. In Taiwan, sub-areas in the Baichi catchment in the North and in the Huaguoshan catchment in the southern-central part of the island are selected; in Austria, landslide-affected sites in the Upper Salzach catchment in the federal state of Salzburg are investigated. For both regions

  7. The use of remote sensing for landslide studies in Europe (United States)

    Tofani, Veronica; Agostini, Andrea; Segoni, Samuele; Catani, Filippo; Casagli, Nicola


    The existing remote sensing techniques and their actual application in Europe for landslide detection, mapping and monitoring have been investigated. Data and information necessary to evaluate the subjects have been collected through a questionnaire, designed using a Google form, which was disseminated among end-users and researchers involved in landslide. In total, 49 answers were collected, coming from 17 European countries and from different kinds of institutions (universities, research institutes, public institutes and private companies). The spatial distribution of the answers is consistent with the distribution of landslides in Europe, the significance of landslides impact on society and the estimated landslide susceptibility in the various countries. The outcomes showed that landslide detection and mapping is mainly performed with aerial photos, often associated with optical and radar imagery. Concerning landslide monitoring, satellite radars prevail over the other types of data followed by aerial photos and meteorological sensors. Since subsampling the answers according to the different typology of institutions it is not noticeable a clear gap between research institutes and end users, it is possible to infer that in landslide remote sensing the research is advancing at the same pace as its day-to-day application. Apart from optical and radar imagery, other techniques are less widespread and some of them are not so well established, notwithstanding their performances are increasing at a fast rate as scientific and technological improvements are accomplished. Remote sensing is mainly used for detection/mapping and monitoring of slides, flows and lateral spreads with a preferably large scale of analysis (1:5000 - 1:25000). All the compilers integrate remote sensing data with other thematic data, mainly geological maps, landslide inventory maps and DTMs and derived maps. Concerning landslide monitoring, the results of the questionnaire stressed that the best

  8. The inner structure of landslides and landslide-prone slopes in south German cuesta landscapes assessed by geophysical, geomorphological and sedimentological approaches (United States)

    Schwindt, Daniel; Sandmeier, Christine; Büdel, Christian; Jäger, Daniel; Wilde, Martina; Terhorst, Birgit


    Investigations on landslide activity in the cuesta landscape of Germany, usually characterized by an interbedding of morphologically hard (e.g. sand-/limestones) and soft (clay) sedimentary rocks are relatively sparse. However, spring 2013 has once again revealed a high susceptibility of the slopes in the Franconian and Swabian Alb to mass movements, when enduring rainfalls initiated numerous landslides causing considerable damage to settlements and infrastructure. Many aspects like the spatial distribution of landslides, triggering factors, and process dynamics - especially with view on the reactivation of landslides - require intensive investigations to allow for assessment of the landslide vulnerability and the development of reliable early-warning systems. Aim of the study is to achieve a deeper insight into the triggering factors and the process dynamics of landslides in the cuesta landscape with special regard on landslide proneness of slopes and the potential reactivation of old landslides. A multi-methodological approach was conducted based on geophysical investigations (seismic refraction tomography - SRT, electrical resistivity tomography - ERT), geomorphological mapping, morphometric GIS-based analysis, core soundings and substrate mapping. Study sites are located in the Swabian Alb (southwestern Germany) in the Jurassic escarpment where where Oxfordian marls and limestones superimpose Callovian clays, as well as in the northeastern Franconian Alb, within the escarpment of the so called Rhätolias with with red claystones of the late Norian (Feuerletten formation) below interbedding layers of sand- and claystones of the Rhaetian (Upper Triassic) and Hettangian ( Lower Jurassic). The investigated landslides strongly differ with respect to their age, from young landslides originated in spring 2013 to ancient landslides. Investigations reveal a distinct diversity of landslide types composed of a complex combination of processes. The applied methods allow

  9. Landslide detection using very high-resolution satellite imageries (United States)

    Suga, Yuzo; Konishi, Tomohisa


    The heavy rain induced by the 12th typhoon caused landslide disaster at Kii Peninsula in the middle part of Japan. We propose a quick response method for landslide disaster mapping using very high resolution (VHR) satellite imageries. Especially, Synthetic Aperture Radar (SAR) is effective because it has the capability of all weather and day/night observation. In this study, multi-temporal COSMO-SkyMed imageries were used to detect the landslide areas. It was difficult to detect the landslide areas using only backscatter change pattern derived from pre- and post-disaster COSMOSkyMed imageries. Thus, the authors adopted a correlation analysis which the moving window was selected for the correlation coefficient calculation. Low value of the correlation coefficient reflects land cover change between pre- and post-disaster imageries. This analysis is effective for the detection of landslides using SAR data. The detected landslide areas were compared with the area detected by EROS-B high resolution optical image. In addition, we have developed 3D viewing system for geospatial visualizing of the damaged area using these satellite image data with digital elevation model. The 3D viewing system has the performance of geographic measurement with respect to elevation height, area and volume calculation, and cross section drawing including landscape viewing and image layer construction using a mobile personal computer with interactive operation. As the result, it was verified that a quick response for the detection of landslide disaster at the initial stage could be effectively performed using optical and SAR very high resolution satellite data by means of 3D viewing system.

  10. Landslide Geohazard Monitoring, Early Warning and Stabilization Control Methods (United States)

    Bednarczyk, Zbigniew


    This paper is a presentation of landslide monitoring, early warning and remediation methods recommended for the Polish Carpathians. Instrumentation included standard and automatic on-line measurements with the real-time transfer of data to an Internet web server. The research was funded through EU Innovative Economy Programme and also by the SOPO Landslide Counteraction Project. The landslides investigated were characterized by relatively low rates of the displacements. These ranged from a few millimetres to several centimetres per year. Colluviums of clayey flysch deposits were of a soil-rock type with a very high plasticity and moisture content. The instrumentation consisted of 23 standard inclinometers set to depths of 5-21 m. The starting point of monitoring measurements was in January 2006. These were performed every 1-2 months over the period of 8 years. The measurements taken detected displacements from several millimetres to 40 cm set at a depth of 1-17 m. The modern, on-line monitoring and early warning system was installed in May 2010. The system is the first of its kind in Poland and only one of several such real-time systems in the world. The installation was working with the Local Road Authority in Gorlice. It contained three automatic field stations for investigation of landslide parameters to depths of 12-16 m and weather station. In-place tilt transducers and innovative 3D continuous inclinometer systems with sensors located every 0.5 m were used. It has the possibility of measuring a much greater range of movements compared to standard systems. The conventional and real-time data obtained provided a better recognition of the triggering parameters and the control of geohazard stabilizations. The monitoring methods chosen supplemented by numerical modelling could lead to more reliable forecasting of such landslides and could thus provide better control and landslide remediation possibilities also to stabilization works which prevent landslides.

  11. DTMs Assessment to the Definition of Shallow Landslides Prone Areas (United States)

    Martins, Tiago D.; Oka-Fiori, Chisato; Carvalho Vieira, Bianca; Montgomery, David R.


    Predictive methods have been developed, especially since the 1990s, to identify landslide prone areas. One of the examples it is the physically based model SHALSTAB (Shallow Landsliding Stability Model), that calculate the potential instability for shallow landslides based on topography and physical soil properties. Normally, in such applications in Brazil, the Digital Terrain Model (DTM), is obtained mainly from conventional contour lines. However, recently the LiDAR (Light Detection and Ranging) system has been largely used in Brazil. Thus, this study aimed to evaluate different DTM's, generated from conventional data and LiDAR, and their influence in generating susceptibility maps to shallow landslides using SHALSTAB model. For that were analyzed the physical properties of soil, the response of the model when applying conventional topographical data and LiDAR's in the generation of DTM, and the shallow landslides susceptibility maps based on different topographical data. The selected area is in the urban perimeter of the municipality of Antonina (PR), affected by widespread landslides in March 2011. Among the results, it was evaluated different LiDAR data interpolation, using GIS tools, wherein the Triangulation/Natural Neighbor presented the best performance. It was also found that in one of evaluation indexes (Scars Concentration), the LiDAR derived DTM presented the best performance when compared with the one originated from contour lines, however, the Landslide Potential index, has presented a small increase. Consequently, it was possible to assess the DTM's, and the one derived from LiDAR improved very little the certitude percentage. It is also noted a gap in researches carried out in Brazil on the use of products generated from LiDAR data on geomorphological analysis.

  12. Landslide scaling and magnitude-frequency distribution (Invited) (United States)

    Stark, C. P.; Guzzetti, F.


    Landslide-driven erosion is controlled by the scale and frequency of slope failures and by the consequent fluxes of debris off the hillslopes. Here I focus on the magnitude-frequency part of the process and develop a theory of initial slope failure and debris mobilization that reproduces the heavy-tailed distributions (PDFs) observed for landslide source areas and volumes. Landslide rupture propagation is treated as a quasi-static, non-inertial process of simplified elastoplastic deformation with strain weakening; debris runout is not considered. The model tracks the stochastically evolving imbalance of frictional, cohesive, and body forces across a failing slope, and uses safety-factor concepts to convert the evolving imbalance into a series of incremental rupture growth or arrest probabilities. A single rupture is simulated with a sequence of weighted ``coin tosses'' with weights set by the growth probabilities. Slope failure treated in this stochastic way is a survival process that generates asymptotically power-law-tail PDFs of area and volume for rock and debris slides; predicted scaling exponents are consistent with analyses of landslide inventories. The primary control on the shape of the model PDFs is the relative importance of cohesion over friction in setting slope stability: the scaling of smaller, shallower failures, and the size of the most common landslide volumes, are the result of the low cohesion of soil and regolith, whereas the negative power-law tail scaling for larger failures is tied to the greater cohesion of bedrock. The debris budget may be dominated by small or large landslides depending on the scaling of both the PDF and of the depth-length relation. I will present new model results that confirm the hypothesis that depth-length scaling is linear. Model PDF of landslide volumes.

  13. Landslide Geohazard Monitoring, Early Warning and Stabilization Control Methods

    Directory of Open Access Journals (Sweden)

    Bednarczyk Zbigniew


    Full Text Available This paper is a presentation of landslide monitoring, early warning and remediation methods recommended for the Polish Carpathians. Instrumentation included standard and automatic on-line measurements with the real-time transfer of data to an Internet web server. The research was funded through EU Innovative Economy Programme and also by the SOPO Landslide Counteraction Project. The landslides investigated were characterized by relatively low rates of the displacements. These ranged from a few millimetres to several centimetres per year. Colluviums of clayey flysch deposits were of a soil-rock type with a very high plasticity and moisture content. The instrumentation consisted of 23 standard inclinometers set to depths of 5-21 m. The starting point of monitoring measurements was in January 2006. These were performed every 1-2 months over the period of 8 years. The measurements taken detected displacements from several millimetres to 40 cm set at a depth of 1-17 m. The modern, on-line monitoring and early warning system was installed in May 2010. The system is the first of its kind in Poland and only one of several such real-time systems in the world. The installation was working with the Local Road Authority in Gorlice. It contained three automatic field stations for investigation of landslide parameters to depths of 12-16 m and weather station. In-place tilt transducers and innovative 3D continuous inclinometer systems with sensors located every 0.5 m were used. It has the possibility of measuring a much greater range of movements compared to standard systems. The conventional and real-time data obtained provided a better recognition of the triggering parameters and the control of geohazard stabilizations. The monitoring methods chosen supplemented by numerical modelling could lead to more reliable forecasting of such landslides and could thus provide better control and landslide remediation possibilities also to stabilization works which

  14. The impacts of formative system on the landslides of Iran

    Directory of Open Access Journals (Sweden)

    Mojgan Entezari Najafabadi


    Full Text Available Landslide is one of the most challenging disasters on the earth, which is believed to cause other natural catastrophic incidents. Normally, in studying landslide we investigate different influencing factors such as gender land, atmospheric rainfall, gradients’ change, earthquake, volcanic eruption, subterranean water vibration, and human causes in the form of different models. These facts are blamed as the main share in appearing this phenomenon. However, correlative and sufficient condition for genesis such a phenomenon is historical base of lands’ bed, which needs specific formative process. There are several studies focused on distribution and dispersion of slides and their reasons. In this paper, we investigate the behavior of landslide and its effects on instigating instabilities. The preliminary results indicate that distribution of this phenomenon is associated with climate from a side and historical formative process on the other side. The weather condition of Iran is divided into four groups of cold, hot, humid and humid hot hole. Every region has its own special geomorphic properties and either directly or indirectly affects on landslide occurrence. In order to study this effect, we use Arc GIS 9.3 software dispersal map of Iran’s main landslides and formative systems on the other side and by local analyzing these two collections are evaluated based on their vicinity relationship using local-statistical techniques. Results of this research shows that the main part of this landslide occurs in cold hole and humid hole and only about 8 percent are happens in hot holl. In addition, density of landslides are more in thermodynamic bound of cold and hot hole as well as cold and humid hole.


    Directory of Open Access Journals (Sweden)

    N. Mijani


    Full Text Available Landslide is one of the main geomorphic processes which effects on the development of prospect in mountainous areas and causes disastrous accidents. Landslide is an event which has different uncertain criteria such as altitude, slope, aspect, land use, vegetation density, precipitation, distance from the river and distance from the road network. This research aims to compare and evaluate different fuzzy-based models including Fuzzy Analytic Hierarchy Process (Fuzzy-AHP, Fuzzy Gamma and Fuzzy-OR. The main contribution of this paper reveals to the comprehensive criteria causing landslide hazard considering their uncertainties and comparison of different fuzzy-based models. The quantify of evaluation process are calculated by Density Ratio (DR and Quality Sum (QS. The proposed methodology implemented in Sari, one of the city of Iran which has faced multiple landslide accidents in recent years due to the particular environmental conditions. The achieved results of accuracy assessment based on the quantifier strated that Fuzzy-AHP model has higher accuracy compared to other two models in landslide hazard zonation. Accuracy of zoning obtained from Fuzzy-AHP model is respectively 0.92 and 0.45 based on method Precision (P and QS indicators. Based on obtained landslide hazard maps, Fuzzy-AHP, Fuzzy Gamma and Fuzzy-OR respectively cover 13, 26 and 35 percent of the study area with a very high risk level. Based on these findings, fuzzy-AHP model has been selected as the most appropriate method of zoning landslide in the city of Sari and the Fuzzy-gamma method with a minor difference is in the second order.

  16. Reprint of "A proposed cell model for multiple-occurrence regional landslide events: Implications for landslide susceptibility mapping" (United States)

    Crozier, M. J.


    Multiple-occurrence regional landslide events (MORLEs) consist of hundreds to thousands of shallow landslides occurring more or less simultaneously within defined areas, ranging from tens to thousands of square kilometres. While MORLEs can be triggered by rainstorms and earthquakes, this paper is confined to those landslide events triggered by rainstorms. Globally, MORLEs occur in a range of geological settings in areas of moderate to steep slopes subject to intense rainstorms. Individual landslides in rainstorm-triggered events are dominantly small, shallow debris and earth flows, and debris and earth slides involving regolith or weathered bedrock. The model used to characterise these events assumes that energy distribution within the event area is represented on the land surface by a cell structure; with maximum energy expenditure within an identifiable core and rapid dissipation concentrically away from the centre. The version of the model presented here has been developed for rainfall-triggered landslide events. It proposes that rainfall intensity can be used to determine different critical landslide response zones within the cell (referred to as core, middle, and periphery zones). These zones are most readily distinguished by two conditions: the proportion of the slope that fails and the particular type of the slope stability factor that assumes dominance in determining specific sites of landslide occurrence. The latter condition means that the power of any slope stability factor to distinguish between stable and unstable sites varies throughout the affected area in accordance with the landslide response zones within the cell; certain factors critical for determining the location of landslide sites in one part of the event area have little influence in other parts of the event area. The implication is that landslide susceptibility maps (and subsequently derived mitigation measures) based on conventional slope stability factors may have only limited validity

  17. GIS Supported Landslide Susceptibility Modeling at Regional Scale: An Expert-Based Fuzzy Weighting Method

    Directory of Open Access Journals (Sweden)

    Christos Chalkias


    Full Text Available The main aim of this paper is landslide susceptibility assessment using fuzzy expert-based modeling. Factors that influence landslide occurrence, such as elevation, slope, aspect, lithology, land cover, precipitation and seismicity were considered. Expert-based fuzzy weighting (EFW approach was used to combine these factors for landslide susceptibility mapping (Peloponnese, Greece. This method produced a landslide susceptibility map of the investigated area. The landslides under investigation have more or less same characteristics: lateral based and downslope shallow movement of soils or rocks. The validation of the model reveals, that predicted susceptibility levels are found to be in good agreement with the past landslide occurrences. Hence, the obtained landslide susceptibility map could be acceptable, for landslide hazard prevention and mitigation at regional scale.

  18. Analysis of stresses on buried pipeline subjected to landslide based on numerical simulation and regression analysis

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bing; Jing, Hongyuan; Liu, Jianping; Wu, Zhangzhong [PetroChina Pipeline RandD Center, Langfang, Hebei (China); Hao, Jianbin [School of Petroleum Engineering, Southwest Petroleum University, Chengdu, Sichuan (China)


    Landslides have a serious impact on the integrity of oil and gas pipelines in the tough terrain of Western China. This paper introduces a solving method of axial stress, which uses numerical simulation and regression analysis for the pipelines subjected to landslides. Numerical simulation is performed to analyze the change regularity of pipe stresses for the five vulnerability assessment indexes, which are: the distance between pipeline and landslide tail; the thickness of landslide; the inclination angle of landslide; the pipeline length passing through landslide; and the buried depth of pipeline. A pipeline passing through a certain landslide in southwest China was selected as an example to verify the feasibility and effectiveness of this method. This method has practical applicability, but it would need large numbers of examples to better verify its reliability and should be modified accordingly. Also, it only considers the case where the direction of the pipeline is perpendicular to the primary slip direction of the landslide.

  19. Application of a complex assessment of landslide hazards in mountain regions

    Directory of Open Access Journals (Sweden)

    Kateryna E. Boyko


    Full Text Available The main regional factors of occurrence and activation of landslides within the mountain region were examined. As a result of study of recommendations made by experts, geologists, and gap analysis of existing methods of forecasting the landslide process, an algorithm of comprehensive assessment of landslide hazard areas based on the construction of models in a GIS environment was proposed. These models describe the spatial patterns of landslides. All factors determining the tendency of the studies area to the landslide process development were divided into actual factors, reflecting the regional peculiarities of the territory and forming the landslide-prone slopes (static model, as well as triggering factors, initiating the landslide process and determining its activity (dynamic model. The first cartographic model was built, showing the distribution of the deterministic indirect indicator of landslide hazard, i.e. stability index.

  20. BCDC Bay Trail Alignment 2009 (United States)

    California Natural Resource Agency — The Bay Trail provides easily accessible recreational opportunities for outdoor enthusiasts, including hikers, joggers, bicyclists and skaters. It also offers a...

  1. Application of a hybrid model of neural networks and genetic algorithms to evaluate landslide susceptibility (United States)

    Wang, H. B.; Li, J. W.; Zhou, B.; Yuan, Z. Q.; Chen, Y. P.


    In the last few decades, the development of Geographical Information Systems (GIS) technology has provided a method for the evaluation of landslide susceptibility and hazard. Slope units were found to be appropriate for the fundamental morphological elements in landslide susceptibility evaluation. Following the DEM construction in a loess area susceptible to landslides, the direct-reverse DEM technology was employed to generate 216 slope units in the studied area. After a detailed investigation, the landslide inventory was mapped in which 39 landslides, including paleo-landslides, old landslides and recent landslides, were present. Of the 216 slope units, 123 involved landslides. To analyze the mechanism of these landslides, six environmental factors were selected to evaluate landslide occurrence: slope angle, aspect, the height and shape of the slope, distance to river and human activities. These factors were extracted in terms of the slope unit within the ArcGIS software. The spatial analysis demonstrates that most of the landslides are located on convex slopes at an elevation of 100-150 m with slope angles from 135°-225° and 40°-60°. Landslide occurrence was then checked according to these environmental factors using an artificial neural network with back propagation, optimized by genetic algorithms. A dataset of 120 slope units was chosen for training the neural network model, i.e., 80 units with landslide presence and 40 units without landslide presence. The parameters of genetic algorithms and neural networks were then set: population size of 100, crossover probability of 0.65, mutation probability of 0.01, momentum factor of 0.60, learning rate of 0.7, max learning number of 10 000, and target error of 0.000001. After training on the datasets, the susceptibility of landslides was mapped for the land-use plan and hazard mitigation. Comparing the susceptibility map with landslide inventory, it was noted that the prediction accuracy of landslide occurrence

  2. A study of the distribution, characteristics, behaviour and triggering mechanisms of Nicaraguan landslides


    Devoli, Graziella


    The thesis investigates and proposes a suitable form of collecting, organizing and analysing landslide data in order to improve the knowledge of landslide processes in Central America. The study recommends the organization of existing and new data in a national landslide database for Nicaragua in a digital format. The database is intended to support the scientific community and local and national authorities in landslide hazard assessment, emergency management, land-use planning and the devel...


    Directory of Open Access Journals (Sweden)

    K. M. Lyapishev


    Full Text Available This article is an overview of researches of landslides using remote sensing methods such as aerial photography, satellite images, radar interferometry, and their combination with the use of GIS technology. Modern methods of investigation of landslides are very diverse. The authors propose different approaches to the identification, classification and monitoring of landslides. Data analysis techniques can help in creating more sophisticated approach to the analysis of landslides.

  4. Landslide hazards and systems analysis: A Central European perspective (United States)

    Klose, Martin; Damm, Bodo; Kreuzer, Thomas


    Part of the problem with assessing landslide hazards is to understand the variable settings in which they occur. There is growing consensus that hazard assessments require integrated approaches that take account of the coupled human-environment system. Here we provide a synthesis of societal exposure and vulnerability to landslide hazards, review innovative approaches to hazard identification, and lay a focus on hazard assessment, while presenting the results of historical case studies and a landslide time series for Germany. The findings add to a growing body of literature that recognizes societal exposure and vulnerability as a complex system of hazard interactions that evolves over time as a function of social change and development. We therefore propose to expand hazard assessments by the framework and concepts of systems analysis (e.g., Liu et al., 2007) Results so far have been promising in ways that illustrate the importance of feedbacks, thresholds, surprises, and time lags in the evolution of landslide hazard and risk. In densely populated areas of Central Europe, landslides often occur in urbanized landscapes or on engineered slopes that had been transformed or created intentionally by human activity, sometimes even centuries ago. The example of Germany enables to correlate the causes and effects of recent landslides with the historical transition of urbanization to urban sprawl, ongoing demographic change, and some chronic problems of industrialized countries today, including ageing infrastructures or rising government debts. In large parts of rural Germany, the combination of ageing infrastructures, population loss, and increasing budget deficits starts to erode historical resilience gains, which brings especially small communities to a tipping point in their efforts to risk reduction. While struggling with budget deficits and demographic change, these communities are required to maintain ageing infrastructures that are particularly vulnerable to

  5. Detection of rainfall-induced landslides on regional seismic networks (United States)

    Manconi, Andrea; Coviello, Velio; Gariano, Stefano Luigi; Picozzi, Matteo


    Seismic techniques are increasingly adopted to detect signals induced by mass movements and to quantitatively evaluate geo-hydrological hazards at different spatial and temporal scales. By analyzing landslide-induced seismicity, it is possible obtaining significant information on the source of the mass wasting, as well as on its dynamics. However, currently only few studies have performed a systematic back analysis on comprehensive catalogues of events to evaluate the performance of proposed algorithms. In this work, we analyze a catalogue of 1058 landslides induced by rainfall in Italy. Among these phenomena, there are 234 rock falls, 55 debris flows, 54 mud flows, and 715 unspecified shallow landslides. This is a subset of a larger catalogue collected by the Italian research institute for geo-hydrological protection (CNR IRPI) during the period 2000-2014 (Brunetti et al., 2015). For each record, the following information are available: the type of landslide; the geographical location of the landslide (coordinates, site, municipality, province, and 3 classes of geographic accuracy); the temporal information on the landslide occurrence (day, month, year, time, date, and 3 classes of temporal accuracy); the rainfall conditions (rainfall duration and cumulated event rainfall) that have resulted in the landslide. We consider here only rainfall-induced landslides for which exact date and time were known from chronicle information. The analysis of coeval seismic data acquired by regional seismic networks show clear signals in at least 3 stations for 64 events (6% of the total dataset). Among them, 20 are associated to local earthquakes and 2 to teleseisms; 10 are anomalous signals characterized by irregular and impulsive waveforms in both time and frequency domains; 33 signals are likely associated to the landslide occurrence, as they have a cigar-shaped waveform characterized by emerging onsets, duration of several tens of seconds, and low frequencies (1-10 Hz). For

  6. Geological control of earthquake induced landslide in El Salvador (United States)

    Tsige Aga, Meaza


    Geological control of earthquake induced landslides in El Salvador. M., Tsige(1), I., Garcia-Flórez(1), R., Mateos(2) (1)Universidad Complutense de Madrid, Facultad de Geología, Madrid, Spain, ( (2)IGME, Mallorca El Salvador is located at one of the most seismically active areas en Central America, and suffered severe damage and loss of life in historical and recent earthquakes, as a consequence of earthquake induced landslides. The most common landslides were shallow disrupted soil-slides on steep slopes and were particularly dense in the central part of the country. Most of them are cited in the recent mechanically weak volcanic pyroclastic deposits known as "Tierra Blanca" and "Tierra Color Café" which are prone to seismic wave amplification and are supposed to have contributed to the triggering of some of the hundreds of landslides related to the 2001 (Mw = 7.6 and Mw = 6.7), seismic events. The earthquakes also triggered numerous deep large scale landslides responsible for the enormous devastation of villages and towns and are the source for the current high seismic hazard as well. Many of these landslides are located at distances more than 50 and 100 km from the focal distance, although some of them occurred at near field. Until now there has been little effort to explain the causes and concentration of the deep large-scale landslides especially their distribution, failure mechanism and post-rapture behavior of the landslide mass (long run-out). It has been done a field investigation of landslides, geological materiales and interpretation of aerial photographs taken before and after the two 2001 (Mw= 7.6 and Mw= 6.7) El Salvador earthquakes. The result of the study showed that most of the large-scale landslides occured as coherent block slides with the sliding surface parallel to a pre-existing fractures and fault planes (La Leona, Barriolera, El Desague, Jiboa landslides). Besides that the pre-existing fractures are weak zones controlling

  7. An Assessment of Monsoon Triggered Landslides in Western Nepal (United States)

    Sudan Acharya, Madhu


    Due to heavy monsoon rain, rugged topography and very young mountains, frequent slope failures and soil erosion are very common in Nepal but in most of cases the natural slopes are disturbed by men to construct a road through it and the situation further aggravated by the Monsoon rain. Summer usually tests the disaster response capacity of Nepal, when the monsoons trigger water induced disasters. This year Nepal's Western regions were most severely affected by floods and landslides. Every year, sadly, it is the same story of mostly poor people living in remote villages succumbing to landslides and flooding and those who survive facing hardships brought on by the disaster. The tail end of the monsoon in October has triggered flood and landslides in Nepal which affected a total of 14 districts in the mid and far-west regions, of which Kailali, Bardiya, Banke, Dadeldhura, Accham and Kanchapur district are most affected. The affected areas are geographically scattered and remote, and are therefore difficult to access. In this year (2009), flood and landslides have claimed 62 lives, affecting more than 152,000 individuals from 27,000 families. More than 4,000 families are displaced and are taking shelter in schools, open space and forest areas with no protection from the external elements. In the above context the prevention and mitigation measures for landslides is a great challenge for Nepal. Nepal has been investing its huge amount of resources to stabilize landslides and roadside slope failures, still then it has become unmanageable during Monsoon time. Considering the above facts, an assessment of landslides which were occurred during the Monsoon (July-October 2009), along Khodpe - Jhota - Chainpur road in far western region of Nepal has been carried out based on the field observation of various landslides. The paper presents the causes and mechanisms of failures of different landslides which are mostly triggered by Monsoon rain. It also suggests some low cost

  8. Hyperspectral and thermal methodologies applied to landslide monitoring (United States)

    Vellico, Michela; Sterzai, Paolo; Pietrapertosa, Carla; Mora, Paolo; Berti, Matteo; Corsini, Alessandro; Ronchetti, Francesco; Giannini, Luciano; Vaselli, Orlando


    Landslide monitoring is a very actual topic. Landslides are a widespread phenomenon over the European territory and these phenomena have been responsible of huge economic losses. The aim of the WISELAND research project (Integrated Airborne and Wireless Sensor Network systems for Landslide Monitoring), funded by the Italian Government, is to test new monitoring techniques capable to rapidly and successfully characterize large landslides in fine soils. Two active earthflows in the Northern Italian Appenines have been chosen as test sites and investigated: Silla (Bologna Province) and Valoria (Modena Province). The project implies the use of remote sensing methodologies, with particular focus on the joint use of airborne Lidar, hyperspectral and thermal systems. These innovative techniques give promising results, since they allow to detect the principal landslide components and to evaluate the spatial distribution of parameters relevant to landslide dynamics such as surface water content and roughness. In this paper we put the attention on the response of the terrain related to the use of a hyperspectral system and its integration with the complementary information obtained using a thermal sensor. The potentiality of a hyperspectral dataset acquired in the VNIR (Visible Near Infrared field) and of the spectral response of the terrain could be high since they give important information both on the soil and on the vegetation status. Several significant indexes can be calculated, such as NDVI, obtained considering a band in the Red field and a band in the Infrared field; it gives information on the vegetation health and indirectly on the water content of soils. This is a key point that bridges hyperspectral and thermal datasets. Thermal infrared data are closely related to soil moisture, one of the most important parameter affecting surface stability in soil slopes. Effective stresses and shear strength in unsaturated soils are directly related to water content, and

  9. Rainfall thresholds for the possible occurrence of landslides in Italy

    Directory of Open Access Journals (Sweden)

    M. T. Brunetti


    Full Text Available In Italy, rainfall is the primary trigger of landslides that frequently cause fatalities and large economic damage. Using a variety of information sources, we have compiled a catalogue listing 753 rainfall events that have resulted in landslides in Italy. For each event in the catalogue, the exact or approximate location of the landslide and the time or period of initiation of the slope failure is known, together with information on the rainfall duration D, and the rainfall mean intensity I, that have resulted in the slope failure. The catalogue represents the single largest collection of information on rainfall-induced landslides in Italy, and was exploited to determine the minimum rainfall conditions necessary for landslide occurrence in Italy, and in the Abruzzo Region, central Italy. For the purpose, new national rainfall thresholds for Italy and new regional rainfall thresholds for the Abruzzo Region were established, using two independent statistical methods, including a Bayesian inference method and a new Frequentist approach. The two methods proved complementary, with the Bayesian method more suited to analyze small data sets, and the Frequentist method performing better when applied to large data sets. The new regional thresholds for the Abruzzo Region are lower than the new national thresholds for Italy, and lower than the regional thresholds proposed in the literature for the Piedmont and Lombardy Regions in northern Italy, and for the Campania Region in southern Italy. This is important, because it shows that landslides in Italy can be triggered by less severe rainfall conditions than previously recognized. The Frequentist method experimented in this work allows for the definition of multiple minimum rainfall thresholds, each based on a different exceedance probability level. This makes the thresholds suited for the design of probabilistic schemes for the prediction of rainfall-induced landslides. A scheme based on four

  10. TRMM Applications for Rainfall-Induced Landslide Early Warning (United States)

    Dok, A.; Fukuoka, H.; Hong, Y.


    Early warning system (EWS) is the most effective method in saving lives and reducing property damages resulted from the catastrophic landslides if properly implemented in populated areas of landslide-prone nations. For predicting the occurrence of landslides, it requires examination of empirical relationship between rainfall characteristics and past landslide occurrence. In developed countries like Japan and the US, precipitation is monitored by rain radars and ground-based rain gauge matrix. However, in developing regions like Southeast Asian countries, very limited number of rain gauges is available, and there is no implemented methodology for issuing effective warming of landslides yet. Correspondingly, satellite precipitation monitoring could be therefore a possible and promising solution for launching landslide quasi-real-time early warning system in those countries. It is due to the fact that TMPA (TRMM Multi-satellite Precipitation Analysis) can provides a globally calibration-based sequential scheme for combining precipitation estimates from multiple satellites, and gauge analyses where feasible, at fine scales (3-hourly with 0.25°x0.25° spatial resolution). It is available both after and in quasi-real time, calibrated by TRMM Combined Instrument and TRMM Microwave Imager precipitation product. However, validation of ground based rain gauge and TRMM satellite data in the vulnerable regions is still not yet operative. Snake-line/Critical-line and Soil Water Index (SWI) are used for issuing warning of landslide occurrence in Japan; whereas, Caine criterion is preferable in Europe and western nations. Herewith, it presents rainfall behavior which took place in Beichuan city (located on the 2008 Chinese Wenchuan earthquake fault), Hofu and Shobara cities in Japan where localized heavy rainfall attacked in 2009 and 2010, respectively, from TRMM 3B42RT correlated with ground based rain gauge data. The 1-day rainfall intensity and 15-day cumulative rainfall

  11. Submarine landslides in Arctic sedimentation: Canada Basin (United States)

    Mosher, David C.; Shimeld, John; Hutchinson, Deborah R.; Lebedova-Ivanova, N; Chapman, C.


    Canada Basin of the Arctic Ocean is the least studied ocean basin in the World. Marine seismic field programs were conducted over the past 6 years using Canadian and American icebreakers. These expeditions acquired more than 14,000 line-km of multibeam bathymetric and multi-channel seismic reflection data over abyssal plain, continental rise and slope regions of Canada Basin; areas where little or no seismic reflection data existed previously. Canada Basin is a turbidite-filled basin with flat-lying reflections correlateable over 100s of km. For the upper half of the sedimentary succession, evidence of sedimentary processes other than turbidity current deposition is rare. The Canadian Archipelago and Beaufort Sea margins host stacked mass transport deposits from which many of these turbidites appear to derive. The stratigraphic succession of the MacKenzie River fan is dominated by mass transport deposits; one such complex is in excess of 132,000 km2 in area and underlies much of the southern abyssal plain. The modern seafloor is also scarred with escarpments and mass failure deposits; evidence that submarine landsliding is an ongoing process. In its latest phase of development, Canada Basin is geomorphologically confined with stable oceanographic structure, resulting in restricted depositional/reworking processes. The sedimentary record, therefore, underscores the significance of mass-transport processes in providing sediments to oceanic abyssal plains as few other basins are able to do.

  12. Experiences from site-specific landslide early warning systems (United States)

    Michoud, C.; Bazin, S.; Blikra, L. H.; Derron, M.-H.; Jaboyedoff, M.


    Landslide early warning systems (EWSs) have to be implemented in areas with large risk for populations or infrastructures when classical structural remediation measures cannot be set up. This paper aims to gather experiences of existing landslide EWSs, with a special focus on practical requirements (e.g., alarm threshold values have to take into account the smallest detectable signal levels of deployed sensors before being established) and specific issues when dealing with system implementations. Within the framework of the SafeLand European project, a questionnaire was sent to about one-hundred institutions in charge of landslide management. Finally, we interpreted answers from experts belonging to 14 operational units related to 23 monitored landslides. Although no standard requirements exist for designing and operating EWSs, this review highlights some key elements, such as the importance of pre-investigation work, the redundancy and robustness of monitoring systems, the establishment of different scenarios adapted to gradual increasing of alert levels, and the necessity of confidence and trust between local populations and scientists. Moreover, it also confirms the need to improve our capabilities for failure forecasting, monitoring techniques and integration of water processes into landslide conceptual models.

  13. Human activity and damaging landslides and floods on Madeira Island (United States)

    Baioni, D.


    Over the last few decades, the island of Madeira has become an important offshore tourism and business center, with rapid economic and demographic development that has caused changes to the landscape due to human activity. In Madeira's recent history, there has been an increase over time in the frequency of occurrence of damaging landslide and flood events. As a result, the costs of restoration work due to damage caused by landslide and flood events have become a larger and larger component of Madeira's annual budget. Landslides and floods in Madeira deserve particular attention because they represent the most serious hazard to human life, to property, and to the natural environment and its important heritage value. The work reported on in this paper involved the analysis of historical data regarding damaging landslide and flood events on Madeira (in particular from 1941 to 1991) together with data on geological characteristics, topographic features, and climate, and from field observations. This analysis showed that the main factor triggering the occurrence of damaging landslide and flood events is rainfall, but that the increase in the number of damaging events recorded on Madeira Island, especially in recent times, seems to be related mostly to human activity, specifically to economic development and population growth, rather than to natural factors.

  14. Warning Model for Shallow Landslides Induced by Extreme Rainfall

    Directory of Open Access Journals (Sweden)

    Lien-Kwei Chien


    Full Text Available In this study, the geophysical properties of the landslide-prone catchment of the Gaoping River in Taiwan were investigated using zones based on landslide history in conjunction with landslide analysis using a deterministic approach based on the TRIGRS (Transient Rainfall Infiltration and Grid-based Regional Slope-Stability model. Typhoon Morakot in 2009 was selected as a simulation scenario to calibrate the combination of geophysical parameters in each zone before analyzing changes in the factor of safety (FS. Considering the amount of response time required for typhoons, suitable FS thresholds for landslide warnings are proposed for each town in the catchment area. Typhoon Fanapi of 2010 was used as a test scenario to verify the applicability of the FS as well as the efficacy of the cumulative rainfall thresholds derived in this study. Finally, the amount of response time provided by the FS thresholds in cases of yellow and red alerts was determined. All five of the landslide events reported by the Soil and Water Conservation Bureau were listed among the unstable sites identified in the proposed model, thereby demonstrating its effectiveness and accuracy in determining unstable areas and areas that require evacuation. These cumulative rainfall thresholds provide a valuable reference to guide disaster prevention authorities in the issuance of yellow and red alerts with the ability to reduce losses and save lives.

  15. A review on the study of landslides triggered by rains

    International Nuclear Information System (INIS)

    Aristizabal E; Martinez H; Velez J I


    This article attempts to give a very detailed perspective to the challenge and advances associated to rainfall-triggered landslides, which are characteristic and very common in tropical environments, such as Colombia. Landslides are one of the most common hazards around the world. Economic losses caused by landslides are huge, and are often exaggerated due to urban sprawl. Recent findings in this topic around the world have been applied for determining critical thresholds by physical or statistical models, combined with rainfall forecasting and near real time monitoring as fundamental component of an early warning system. Landslides are caused by several phenomena, including geological, geomorphologic and anthropogenic dynamics; however, one variable - precipitation - has a uniquely strong capability to cause rapid, intense slope failure. A review of several studies of rainfall-triggered landslides is presented some of who have used statistical tools that define critical thresholds based on intensity and duration rainfall. Other authors have focused upon physical based models combining hydrological and geotechnical aspects of rainfall, water pore pressure and slope stability.

  16. Management of a typhoon-induced landslide in Otomura (Japan) (United States)

    Fujisawa, Kazunori; Marcato, Gianluca; Nomura, Yasuhiro; Pasuto, Alessandro


    Late in January 2004 slope instability evidence such as cracks and subsidence appeared on a retaining wall along National Highway 168, near Otomura (Nara Prefecture, Japan). This road plays a strategic role as a long distance route for passenger vehicles and trucks, therefore detailed investigations and constant surveillance have to be carried out in order to manage the induced risk situations. Six months later, on August 10th, a large landslide occurred due to heavy rainfalls related to typhoons #10 and #11 that hit Japan on the first week of August. Field and aerial surveys of the site were carried out soon after the appearance of the first geomorphologic evidence of landslide movements, and a monitoring system was immediately set up. Landslide displacements have been measured since the early stage of movement and road traffic was strictly controlled in order to minimize possible damage. This paper illustrates the effects of landslide activation and the investigations carried out in order to assess landslide hazard and predict the time of failure. Suitable methods for risk management oriented to increase the public safety and including risk control and crisis mitigation acts are also discussed.

  17. Apply data mining to analyze the rainfall of landslide

    Directory of Open Access Journals (Sweden)

    Lee Chou-Yuan


    Full Text Available Taiwan is listed as extremely dangerous country which suffers from many disasters. The disasters from the landslide result in the loss of agricultural productions, life and property and so on. Many researchers concern about the disasters of landslide, but there are few discussions for the threshold of rainfall for landslide. In this paper, data mining is applied to establish rules and the threshold of rainfall for landslide in Huafan University, Taiwan. These used variables include rainfall, insolation, insolation rate, averaged humidity, averaged temperature, wind speed, and the tilt of inclinometer. The inclinometer is an important instrument for measuring tilt, elevation or depression of an object with respect to gravity. There are 26 inclinometers in Talun mountain area of Huafan University. In this research, the used data were collected from January 2008 to July 2014. In the proposed approach, the regression analysis is used to predict rainfall first. Then, decision tree is used to obtain decision rules and set the threshold of rainfall for landslide. The output of this approach can provide more information for understanding the change of rainfall. The threshold of rainfall could also provide useful information to maintain the security for Huafan University.

  18. Human activity and damaging landslides and floods on Madeira Island

    Directory of Open Access Journals (Sweden)

    D. Baioni


    Full Text Available Over the last few decades, the island of Madeira has become an important offshore tourism and business center, with rapid economic and demographic development that has caused changes to the landscape due to human activity. In Madeira's recent history, there has been an increase over time in the frequency of occurrence of damaging landslide and flood events. As a result, the costs of restoration work due to damage caused by landslide and flood events have become a larger and larger component of Madeira's annual budget. Landslides and floods in Madeira deserve particular attention because they represent the most serious hazard to human life, to property, and to the natural environment and its important heritage value.

    The work reported on in this paper involved the analysis of historical data regarding damaging landslide and flood events on Madeira (in particular from 1941 to 1991 together with data on geological characteristics, topographic features, and climate, and from field observations. This analysis showed that the main factor triggering the occurrence of damaging landslide and flood events is rainfall, but that the increase in the number of damaging events recorded on Madeira Island, especially in recent times, seems to be related mostly to human activity, specifically to economic development and population growth, rather than to natural factors.

  19. Geospatial Assessment of Coseismic Landslides in Baturagung Area

    Directory of Open Access Journals (Sweden)

    Aditya Saputra


    Full Text Available Java, the most densely populated island in Indonesia, is located on top of the most seismically active areas in Southeast Asia: the Sunda Megathrust. This area is frequently hit by strong earthquake. More than 3,300 M>5earthquakesoccurred between 1973-2014. The wide range of mountainous areas and high intensity of rainfall, make several part of the island one of the most exposed regions for coseismic landslides such as Baturagung area, the Southeast mountainous area of Yogyakarta Province. An integrated method between RS and GIS was used to conduct the vulnerability assessment due to the lack of the site specific slope instability analysis and coseismic landslides data. The seismic zonation of Baturagung area was obtained based on the analysis of Kanai attenuation. The geologic information was extracted using remote sensing interpretation based on the 1:100,000 geologic map of Yogyakarta and geomorphologic map of Baturagung area as well. The coseismic landslide hazard assessment has been estimated using scoring analysis in the GIS platform proposed by Mora and Vahrson (1993 with several modification. The accomplished coseismic landslide hazard map shows medium hazard coverage in the eastern areas, in the upper slope of Baturagung area, which consists of Semilir Formation. The result provides a distinct description of coseismic landslides hazard distribution in Batuaragung area. However, it should only be the preliminary assessment of the site specific investigation especially on valuable area or asset.

  20. GIS-based landslide susceptibility mapping for the 2005 Kashmir earthquake region (United States)

    Kamp, Ulrich; Growley, Benjamin J.; Khattak, Ghazanfar A.; Owen, Lewis A.


    The Mw 7.6 October 8, 2005 Kashmir earthquake triggered several thousand landslides throughout the Himalaya of northern Pakistan and India. These were concentrated in six different geomorphic-geologic-anthropogenic settings. A spatial database, which included 2252 landslides, was developed and analyzed using ASTER satellite imagery and geographical information system (GIS) technology. A multi-criterion evaluation was applied to determine the significance of event-controlling parameters in triggering the landslides. The parameters included lithology, faults, slope gradient, slope aspect, elevation, land cover, rivers and roads. The results showed four classes of landslide susceptibility. Furthermore, they indicated that lithology had the strongest influence on landsliding, particularly when the rock is highly fractured, such as in shale, slate, clastic sediments, and limestone and dolomite. Moreover, the proximity of the landslides to faults, rivers, and roads was also an important factor in helping to initiate failures. In addition, landslides occurred particularly in moderate elevations on south facing slopes. Shrub land, grassland, and also agricultural land were highly susceptible to failures, while forested slopes had few landslides. One-third of the study area was highly or very highly susceptible to future landsliding and requires immediate mitigation action. The rest of the region had a low or moderate susceptibility to landsliding and remains relatively stable. This study supports the view that (1) earthquake-triggered landslides are concentrated in specific zones associated with event-controlling parameters; and (2) in the western Himalaya deforestation and road construction contributed significantly to landsliding during and shortly after earthquakes.

  1. Landslide deposit boundaries for the Little North Santiam River Basin, Oregon (United States)

    Sobieszczyk, Steven


    This layer is an inventory of existing landslides deposits in the Little North Santiam River Basin, Oregon (2009). Each landslide deposit shown on this map has been classified according to a number of specific characteristics identified at the time recorded in the GIS database. The classification scheme was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009). Several significant landslide characteristics recorded in the database are portrayed with symbology on this map. The specific characteristics shown for each landslide are the activity of landsliding, landslide features, deep or shallow failure, type of landslide movement, and confidence of landslide interpretation. These landslide characteristics are determined primarily on the basis of geomorphic features, or landforms, observed for each landslide. This work was completed as part of the Master's thesis "Turbidity Monitoring and LiDAR Imagery Indicate Landslides are Primary Source of Suspended-Sediment Load in the Little North Santiam River Basin, Oregon, Winter 2009-2010" by Steven Sobieszczyk, Portland State University and U.S. Geological Survey.Data layers in this geodatabase include: landslide deposit boundaries (Deposits); field-verfied location imagery (Photos); head scarp or scarp flanks (Scarp_Flanks); and secondary scarp features (Scarps).The geodatabase template was developed by the Oregon Department of Geology and Mineral Industries (Burns and Madin, 2009).

  2. 76 FR 50752 - Proposed Information Collection; Comment Request for the Landslide Report: Did You See It? (United States)


    ... Collection; Comment Request for the Landslide Report: Did You See It? AGENCY: United States Geological Survey... the USGS Landslide Hazards Program's Landslide Report: Did You See It? As required by the Paperwork... information unless it displays a currently valid OMB control number. DATES: You must submit comments on or...

  3. Mapping of landslides under dense vegetation cover using object - oriented analysis and LiDAR derivatives

    NARCIS (Netherlands)

    Van Den Eeckhout, Miet; Kerle, N.; Hervas, Javier; Supper, Robert; Margottini, C.; Canuti, P.; Sassa, K.


    Light Detection and Ranging (LiDAR) and its wide range of derivative products have become a powerful tool in landslide research, particularly for landslide identification and landslide inventory mapping. In contrast to the many studies that use expert-based analysis of LiDAR derivatives to identify

  4. Estimate of landslide deformation and failure time by ESR technique of. alpha. -quartz

    Energy Technology Data Exchange (ETDEWEB)

    Xingzhong, Liang; Mingdong, Chen [Chengdu Coll. of Geology, SC (China); Jiyong, Chen; Jiamin, Feng [Sichuan Univ., Chengdu, SC (China)


    ESR dating has been applied to study landslides. A method of dose-difference to determine the landslide age has been developed. The ESR spectra of annealled quartz grain samples and the optimum conditions of thermal activation were studied. The signifcance of ESR dating of landslide in geological research was discussed.

  5. Airborne laser scanning for forested landslides investigation in temperate and tropical environments

    NARCIS (Netherlands)

    Razak, K.A.


    Landslide hazard and risk have increased over the last decades and pose a significant threat to modern society. Despite remarkable efforts of compiling and updating landslide maps at regional, national or global scales, the number of landslide events is often underestimated, especially in forested

  6. Comparison of the landslide susceptibility models in Taipei Water Source Domain, Taiwan (United States)

    WU, C. Y.; Yeh, Y. C.; Chou, T. H.


    Taipei Water Source Domain, locating at the southeast of Taipei Metropolis, is the main source of water resource in this region. Recently, the downstream turbidity often soared significantly during the typhoon period because of the upstream landslides. The landslide susceptibilities should be analysed to assess the influence zones caused by different rainfall events, and to ensure the abilities of this domain to serve enough and quality water resource. Generally, the landslide susceptibility models can be established based on either a long-term landslide inventory or a specified landslide event. Sometimes, there is no long-term landslide inventory in some areas. Thus, the event-based landslide susceptibility models are established widely. However, the inventory-based and event-based landslide susceptibility models may result in dissimilar susceptibility maps in the same area. So the purposes of this study were to compare the landslide susceptibility maps derived from the inventory-based and event-based models, and to interpret how to select a representative event to be included in the susceptibility model. The landslide inventory from Typhoon Tim in July, 1994 and Typhoon Soudelor in August, 2015 was collected, and used to establish the inventory-based landslide susceptibility model. The landslides caused by Typhoon Nari and rainfall data were used to establish the event-based model. The results indicated the high susceptibility slope-units were located at middle upstream Nan-Shih Stream basin.

  7. Long-term Observation of Soil Creep Activity around a Landslide Scar (United States)

    Rate of sediment infilling into landslide scars by soil creep is needed to estimate the timing of subsequent landslide activity at a particular site. However, knowledge about the spatial distribution of its activity around the landslide scar is scarce. Additionally, there are few...

  8. Humic Substances from Manila Bay and Bolinao Bay Sediments

    Directory of Open Access Journals (Sweden)

    Elma Llaguno


    Full Text Available The C,H,N composition of sedimentary humic acids (HA extracted from three sites in Manila Bay and six sites in Bolinao Bay yielded H/C atomic ratios of 1.1-1.4 and N/C atomic ratios of 0.09 - 0.16. The Manila Bay HA's had lower H/C and N/C ratios compared to those from Bolinao Bay. The IR spectra showed prominent aliphatic C-H and amide I and II bands. Manila Bay HA's also had less diverse molecular composition based on the GC-MS analysis of the CuO and alkaline permanganate oxidation products of the humic acids.

  9. Assessments on landslide susceptibility in the Tseng-wen reservoir watershed, Taiwan (United States)

    Chen, Yu-Chin; Chen, Yung-Chau; Chen, Wen-Fu


    Typhoon Morakot under the strong influence of southwestern monsoon wind struck Taiwan on 8 August 2009, and dumped record-breaking rains in southern Taiwan. It triggered enormous landslides in mountains and severe flooding in low-lying areas. In addition, it destroyed or damaged houses, agricultural fields, roads, bridges, and other infrastructure facilities, causing massive economic loss and, more tragically, human casualties. In order to evaluate landslide hazard and risk assessment, it is important to understand the potential sites of landslide and their spatial distribution. Multi-temporal satellite images and geo-spatial data are used to build landslide susceptibility map for the post-disaster in the Tseng-wen reservoir watershed in this research. Elevation, slope, aspect, NDVI (normalized differential vegetation index), relief, roughness, distance to river, and distance to road are the considered factors for estimating landslide susceptibility. Maximum hourly rainfall and total rainfall, accompanied with typhoon event, are selected as the trigger factors of landslide events. Logistic regression analysis is adopted as the statistical method to model landslide susceptibility. The assessed susceptibility is represented in 4 levels which are high, high-intermediate, intermediate, and low level, respectively. Landslide spatial distribution can be depicted as a landslide susceptibility map with respect to each considered influence factors for a specified susceptible level. The landslide areas are about 358 ha and 1,485 ha before and after typhoon Morakot. The new landslide area, induced by typhoon Morakot, is as almost 4 times as the landslide area before typhoon Morakot. In addition, there is about 44.56% landslide area elevation ranging from 500m to 1000m and about 57.22% average slope ranging from 30° to 45° of landslide area. Furthermore, the devastating landslides were happened at those sites close to rivers, exposed area, and area with big land cover change

  10. Creep and slip: Seismic precursors to the Nuugaatsiaq landslide (Greenland) (United States)

    Poli, Piero


    Precursory signals to material's failure are predicted by numerical models and observed in laboratory experiments or using field data. These precursory signals are a marker of slip acceleration on weak regions, such as crustal faults. Observation of these precursory signals of catastrophic natural events, such as earthquakes and landslides, is necessary for improving our knowledge about the physics of the nucleation process. Furthermore, observing such precursory signals may help to forecast these catastrophic events or reduce their hazard. I report here the observation of seismic precursors to the Nuugaatsiaq landslide in Greenland. Time evolution of the detected precursors implies that an aseismic slip event is taking place for hours before the landslide, with an exponential increase of slip velocity. Furthermore, time evolution of the precursory signals' amplitude sheds light on the evolution of the fault physics during the nucleation process.

  11. Landslide susceptibility and risk assessment: specificities for road networks (United States)

    Pellicani, Roberta; Argentiero, Ilenia; Parisi, Alessandro; Spilotro, Giuseppe


    A regional-scale assessment of landslide susceptibility and risk along the main road corridors crossing the provincial territory of Matera (Basilicata Region, Southern Italy) was carried out. The entire provincial road network extends for about 1,320 km through a territory, of which represents the main connection infrastructure among thirty-one municipalities due to the lack of an efficient integrated transportation system through the whole regional territory. For this reason, the strategic importance of these roads consists in their uniqueness in connecting every urban center with the socio-economic surrounding context. These roads and their vehicular traffic are continuously exposed to instability processes (about the 40% of the total length is disrupted by landslides), characterized both by high intensity and low frequency and by low intensity and high frequency. This last typology, consisting in small shallow landslides, is particularly hazardous for the roads since it is widespread along the road network, its occurrence is connected to rainfalls and determines high vulnerability conditions for the road in terms of interruption of vehicular traffic. A GIS-based heuristic-bivariate statistical predictive model was performed to assess and map the landslide susceptibility in the study area, by using a polynomial function of eight predisposing factors, weighted according to their influence on the landslide phenomena, recognized and collected in an inventory. Susceptibility associated to small shallow phenomena was assessed by using a polynomial function of specific factors, such as slope angle and aspect, lithological outcrops, rainfalls, etc. In absence of detailed input data, the spatial distribution of landslide risk along the road corridors was assessed and mapped using a qualitative hazard-consequence matrix approach, by which risk is obtained by combining hazard categories with consequence classes pairwise in a two-dimensional table or matrix. Landslide

  12. Predictability of Landslide Timing From Quasi-Periodic Precursory Earthquakes (United States)

    Bell, Andrew F.


    Accelerating rates of geophysical signals are observed before a range of material failure phenomena. They provide insights into the physical processes controlling failure and the basis for failure forecasts. However, examples of accelerating seismicity before landslides are rare, and their behavior and forecasting potential are largely unknown. Here I use a Bayesian methodology to apply a novel gamma point process model to investigate a sequence of quasiperiodic repeating earthquakes preceding a large landslide at Nuugaatsiaq in Greenland in June 2017. The evolution in earthquake rate is best explained by an inverse power law increase with time toward failure, as predicted by material failure theory. However, the commonly accepted power law exponent value of 1.0 is inconsistent with the data. Instead, the mean posterior value of 0.71 indicates a particularly rapid acceleration toward failure and suggests that only relatively short warning times may be possible for similar landslides in future.

  13. Regional rainfall thresholds for landslide occurrence using a centenary database (United States)

    Vaz, Teresa; Luís Zêzere, José; Pereira, Susana; Cruz Oliveira, Sérgio; Quaresma, Ivânia


    Rainfall is one of the most important triggering factors for landslides occurrence worldwide. The relation between rainfall and landslide occurrence is complex and some approaches have been focus on the rainfall thresholds identification, i.e., rainfall critical values that when exceeded can initiate landslide activity. In line with these approaches, this work proposes and validates rainfall thresholds for the Lisbon region (Portugal), using a centenary landslide database associated with a centenary daily rainfall database. The main objectives of the work are the following: i) to compute antecedent rainfall thresholds using linear and potential regression; ii) to define lower limit and upper limit rainfall thresholds; iii) to estimate the probability of critical rainfall conditions associated with landslide events; and iv) to assess the thresholds performance using receiver operating characteristic (ROC) metrics. In this study we consider the DISASTER database, which lists landslides that caused fatalities, injuries, missing people, evacuated and homeless people occurred in Portugal from 1865 to 2010. The DISASTER database was carried out exploring several Portuguese daily and weekly newspapers. Using the same newspaper sources, the DISASTER database was recently updated to include also the landslides that did not caused any human damage, which were also considered for this study. The daily rainfall data were collected at the Lisboa-Geofísico meteorological station. This station was selected considering the quality and completeness of the rainfall data, with records that started in 1864. The methodology adopted included the computation, for each landslide event, of the cumulative antecedent rainfall for different durations (1 to 90 consecutive days). In a second step, for each combination of rainfall quantity-duration, the return period was estimated using the Gumbel probability distribution. The pair (quantity-duration) with the highest return period was

  14. Socioeconomic and environmental impacts of landslides in the Western Hemisphere (United States)

    Schuster, Robert L.; Highland, Lynn M.


    In spite of improvements in recognition, prediction, mitigative measures, and warning systems, economic losses and casualties due to landslides in the Western Hemisphere appear to be growing as a result of increasing development of landslide-prone areas due to population pressures. This paper notes outstanding examples of socioeconomic losses in the Americas. Landslides impact the following elements of the natural environment: (1) the topography/morphology of both the subaerial and submarine surfaces of the Earth, (2) rivers, streams, forests, and grasslands, and (3) habitats of native fauna, both on the Earth?s surface and in its streams and oceans. Environmental disturbances are results of general tendency toward degradation of the Earth?s surface by gravitational mass wasting and erosion.

  15. Landslide susceptibility assessment of SE Bartin (West Black Sea region, Turkey by artificial neural networks

    Directory of Open Access Journals (Sweden)

    M. Ercanoglu


    Full Text Available Landslides are significant natural hazards in Turkey, second only to earthquakes with respect to economic losses and casualties. The West Black Sea region of Turkey is known as one of the most landslide-prone regions in the country. The work presented in this paper is aimed at evaluating landslide susceptibility in a selected area in the West Black Sea region using Artificial Neural Network (ANN method. A total of 317 landslides were identified and mapped in the area by extensive field work and by use of air photo interpretations to build a landslide inventory map. A landslide database was then derived automatically from the landslide inventory map. To evaluate landslide susceptibility, six input parameters (slope angle, slope aspect, topographical elevation, topographical shape, wetness index, and vegetation index were used. To obtain maps of these parameters, Digital Elevation Model (DEM and ASTER satellite imagery of the study area were used. At the first stage, all data were normalized in [0, 1] interval, and parameter effects on landslide occurrence were expressed using Statistical Index values (Wi. Then, landslide susceptibility analyses were performed using an ANN. Finally, performance of the resulting map and the applied methodology is discussed relative to performance indicators, such as predicted areal extent of landslides and the strength of relation (rij value. Much of the areal extents of the landslides (87.2% were classified as susceptible to landsliding, and rij value of 0.85 showed a high degree of similarity. In addition to these, at the final stage, an independent validation strategy was followed by dividing the landslide data set into two parts and 82.5% of the validation data set was found to be correctly classified as landslide susceptible areas. According to these results, it is concluded that the map produced by the ANN is reliable and methodology applied in the study produced high performance, and satisfactory results.

  16. Topographic signatures of deep-seated landslides and a general landscape evolution model (United States)

    Booth, A. M.; Roering, J. J.; Rempel, A. W.


    A fundamental goal of studying earth surface processes is to disentangle the complex web of interactions among baselevel, climate, and rock properties that generate characteristic landforms. Mechanistic geomorphic transport laws can quantitatively address this goal, but no widely accepted law for landslides exists. Here, we propose a transport law for deep-seated landslides and demonstrate its utility using a two-dimensional numerical landscape evolution model informed by study areas in the Waipaoa catchment, New Zealand and the Eel River catchment, California. We define a non-dimensional landslide number, which is the ratio of uplift to landslide flow time scales, that predicts three distinct landscape types. The first is dominated by stochastic landsliding, whereby discrete landslide events episodically erode material at rates far exceeding the long term uplift rate. The second is characterized by steady landsliding, in which the landslide flux at any location remains constant through time and is largest at the steepest locations in the catchment. The third is not significantly affected by landsliding. In both the "stochastic landsliding" and "steady landsliding" regimes, increases in the non-dimensional landslide number systematically reduce catchment relief and widen valley spacing, producing long, quasi-planar, low angle hillslopes despite high uplift rates. The stochastic landsliding regime best captures the frequent observation that deep-seated landslides produce a large sediment flux from a small aerial extent while being active only a fraction of the time. We suggest that this model is adaptable to a wide range of geologic settings and may be useful for interpreting climate-driven changes in landslide behavior.

  17. Susceptibility of Shallow Landslide in Fraser Hill Catchment, Pahang Malaysia

    Directory of Open Access Journals (Sweden)

    Wan Nor Azmin Sulaiman


    Full Text Available In tropical areas especially during monsoon seasons intense precipitation is the main caused that trigger the natural shallow landslide phenomena. This phenomenon can be disastrous and widespread in occurrence even in undisturbed forested catchment. In this paper, an attempt has been made to evaluate the susceptibility of natural hill slopes to failure for a popular hill resort area, the Fraser Hill Catchment under different rainfall regimes and soil thickness. A Digital Elevation Model (DEM was prepared for the 8.2 km2 catchment. A GIS based deterministic model was then applied to predict the spatial landslide occurrence within catchment. Model input parameters include bulk density, friction angle, cohesion and hydraulic conductivity were gathered through in situ and lab analysis as well as from previous soil analysis records. Landslides locations were recorded using GPS as well as previous air photos and satellite imagery to establish landslide source areas inventory. The landslide susceptibility map was produced under different precipitation event’s simulation to see the effects of precipitation to stability of the hill slopes of the catchment. The results were categorized into naturally unstable (Defended, Upper Threshold, Lower Threshold, marginal instability (Quasi Stable and stable area (Moderately Stable and Stable. Results of the simulation indicated notable change in precipitation effect on Defended area is between 10mm to 40mm range in a single storm event. However, when storm event is exceeded 120mm, the result on Defended area produced by the model tends to be constant further on. For area categorized as naturally unstable (Factor of Safety, SF<1, with 110 mm of precipitation in a single storm event and soil depth at 2 meters and 4 meters could affect 69.51% and 69.88% respectively of the catchment area fall under that class. In addition, the model was able to detect 4% more of the landslide inventory under shallower soil depth of

  18. A hydroclimatological approach to predicting regional landslide probability using Landlab (United States)

    Strauch, Ronda; Istanbulluoglu, Erkan; Nudurupati, Sai Siddhartha; Bandaragoda, Christina; Gasparini, Nicole M.; Tucker, Gregory E.


    We develop a hydroclimatological approach to the modeling of regional shallow landslide initiation that integrates spatial and temporal dimensions of parameter uncertainty to estimate an annual probability of landslide initiation based on Monte Carlo simulations. The physically based model couples the infinite-slope stability model with a steady-state subsurface flow representation and operates in a digital elevation model. Spatially distributed gridded data for soil properties and vegetation classification are used for parameter estimation of probability distributions that characterize model input uncertainty. Hydrologic forcing to the model is through annual maximum daily recharge to subsurface flow obtained from a macroscale hydrologic model. We demonstrate the model in a steep mountainous region in northern Washington, USA, over 2700 km2. The influence of soil depth on the probability of landslide initiation is investigated through comparisons among model output produced using three different soil depth scenarios reflecting the uncertainty of soil depth and its potential long-term variability. We found elevation-dependent patterns in probability of landslide initiation that showed the stabilizing effects of forests at low elevations, an increased landslide probability with forest decline at mid-elevations (1400 to 2400 m), and soil limitation and steep topographic controls at high alpine elevations and in post-glacial landscapes. These dominant controls manifest themselves in a bimodal distribution of spatial annual landslide probability. Model testing with limited observations revealed similarly moderate model confidence for the three hazard maps, suggesting suitable use as relative hazard products. The model is available as a component in Landlab, an open-source, Python-based landscape earth systems modeling environment, and is designed to be easily reproduced utilizing HydroShare cyberinfrastructure.

  19. Automated reconstruction of rainfall events responsible for shallow landslides (United States)

    Vessia, G.; Parise, M.; Brunetti, M. T.; Peruccacci, S.; Rossi, M.; Vennari, C.; Guzzetti, F.


    Over the last 40 years, many contributions have been devoted to identifying the empirical rainfall thresholds (e.g. intensity vs. duration ID, cumulated rainfall vs. duration ED, cumulated rainfall vs. intensity EI) for the initiation of shallow landslides, based on local as well as worldwide inventories. Although different methods to trace the threshold curves have been proposed and discussed in literature, a systematic study to develop an automated procedure to select the rainfall event responsible for the landslide occurrence has rarely been addressed. Nonetheless, objective criteria for estimating the rainfall responsible for the landslide occurrence (effective rainfall) play a prominent role on the threshold values. In this paper, two criteria for the identification of the effective rainfall events are presented: (1) the first is based on the analysis of the time series of rainfall mean intensity values over one month preceding the landslide occurrence, and (2) the second on the analysis of the trend in the time function of the cumulated mean intensity series calculated from the rainfall records measured through rain gauges. The two criteria have been implemented in an automated procedure written in R language. A sample of 100 shallow landslides collected in Italy by the CNR-IRPI research group from 2002 to 2012 has been used to calibrate the proposed procedure. The cumulated rainfall E and duration D of rainfall events that triggered the documented landslides are calculated through the new procedure and are fitted with power law in the (D,E) diagram. The results are discussed by comparing the (D,E) pairs calculated by the automated procedure and the ones by the expert method.

  20. Seismic Signals of the 2014 Landslide near Oso, Washington (United States)

    Allstadt, K.; Moran, S. C.; Malone, S. D.; Iverson, R. M.; George, D. L.


    The 22 March 2014 landslide near Oso, Washington rapidly moved a large volume of material (~8 million m^3), resulting in the efficient generation of seismic waves that were recorded over 350 km away. Analysis of these seismic signals significantly improves our understanding of the dynamics and timing of events. In contrast to the double couple mechanism of earthquakes, at long periods, the equivalent mechanism of a landslide is a single force. Inversion of the long-period waves for the forces exerted on the earth by the landslide yields a time-series that peaks at nearly 10^10 N and lasts ~1.5 minutes. This result, when combined with higher-frequency wave analysis, eyewitness reports, and field observations, implies a complex failure sequence. The earliest force pulses begin before the buildup in high-frequency energy, suggesting the slide began coherently before transitioning within a minute into the highly disrupted and destructive debris-avalanche flow that killed 43 people. This transition may have been due to a collapse of additional material that loaded the material downslope. Seismically observable "aftershock" landslides continued for weeks. The first and largest occurred a few minutes after the main failure sequence, and was followed by 15 more over the next ~4 hours that were observable at the closest seismic station (11 km away). Three USGS "spiders" equipped with GPS and seismic sensors were deployed by helicopter 10 days later as part of a monitoring effort. Due to their proximity, these seismometers detected signals from even minor collapses, some visually identified by human observers. This augmented network revealed interesting temporal patterns in the post-slide activity, which was dominated by sloughing of material from the headscarp, but also creep of the upper block of the failure mass at a rate of about 1 cm/day. This study shows the value of seismic analysis in landslide investigations to provide timing constraints and help improve our

  1. A hydroclimatological approach to predicting regional landslide probability using Landlab

    Directory of Open Access Journals (Sweden)

    R. Strauch


    Full Text Available We develop a hydroclimatological approach to the modeling of regional shallow landslide initiation that integrates spatial and temporal dimensions of parameter uncertainty to estimate an annual probability of landslide initiation based on Monte Carlo simulations. The physically based model couples the infinite-slope stability model with a steady-state subsurface flow representation and operates in a digital elevation model. Spatially distributed gridded data for soil properties and vegetation classification are used for parameter estimation of probability distributions that characterize model input uncertainty. Hydrologic forcing to the model is through annual maximum daily recharge to subsurface flow obtained from a macroscale hydrologic model. We demonstrate the model in a steep mountainous region in northern Washington, USA, over 2700 km2. The influence of soil depth on the probability of landslide initiation is investigated through comparisons among model output produced using three different soil depth scenarios reflecting the uncertainty of soil depth and its potential long-term variability. We found elevation-dependent patterns in probability of landslide initiation that showed the stabilizing effects of forests at low elevations, an increased landslide probability with forest decline at mid-elevations (1400 to 2400 m, and soil limitation and steep topographic controls at high alpine elevations and in post-glacial landscapes. These dominant controls manifest themselves in a bimodal distribution of spatial annual landslide probability. Model testing with limited observations revealed similarly moderate model confidence for the three hazard maps, suggesting suitable use as relative hazard products. The model is available as a component in Landlab, an open-source, Python-based landscape earth systems modeling environment, and is designed to be easily reproduced utilizing HydroShare cyberinfrastructure.

  2. Hydrodynamic modeling of tsunamis from the Currituck landslide (United States)

    Geist, E.L.; Lynett, P.J.; Chaytor, J.D.


    Tsunami generation from the Currituck landslide offshore North Carolina and propagation of waves toward the U.S. coastline are modeled based on recent geotechnical analysis of slide movement. A long and intermediate wave modeling package (COULWAVE) based on the non-linear Boussinesq equations are used to simulate the tsunami. This model includes procedures to incorporate bottom friction, wave breaking, and overland flow during runup. Potential tsunamis generated from the Currituck landslide are analyzed using four approaches: (1) tsunami wave history is calculated from several different scenarios indicated by geotechnical stability and mobility analyses; (2) a sensitivity analysis is conducted to determine the effects of both landslide failure duration during generation and bottom friction along the continental shelf during propagation; (3) wave history is calculated over a regional area to determine the propagation of energy oblique to the slide axis; and (4) a high-resolution 1D model is developed to accurately model wave breaking and the combined influence of nonlinearity and dispersion during nearshore propagation and runup. The primary source parameter that affects tsunami severity for this case study is landslide volume, with failure duration having a secondary influence. Bottom friction during propagation across the continental shelf has a strong influence on the attenuation of the tsunami during propagation. The high-resolution 1D model also indicates that the tsunami undergoes nonlinear fission prior to wave breaking, generating independent, short-period waves. Wave breaking occurs approximately 40-50??km offshore where a tsunami bore is formed that persists during runup. These analyses illustrate the complex nature of landslide tsunamis, necessitating the use of detailed landslide stability/mobility models and higher-order hydrodynamic models to determine their hazard.

  3. Combining heuristic and statistical techniques in landslide hazard assessments (United States)

    Cepeda, Jose; Schwendtner, Barbara; Quan, Byron; Nadim, Farrokh; Diaz, Manuel; Molina, Giovanni


    As a contribution to the Global Assessment Report 2013 - GAR2013, coordinated by the United Nations International Strategy for Disaster Reduction - UNISDR, a drill-down exercise for landslide hazard assessment was carried out by entering the results of both heuristic and statistical techniques into a new but simple combination rule. The data available for this evaluation included landslide inventories, both historical and event-based. In addition to the application of a heuristic method used in the previous editions of GAR, the availability of inventories motivated the use of statistical methods. The heuristic technique is largely based on the Mora & Vahrson method, which estimates hazard as the product of susceptibility and triggering factors, where classes are weighted based on expert judgment and experience. Two statistical methods were also applied: the landslide index method, which estimates weights of the classes for the susceptibility and triggering factors based on the evidence provided by the density of landslides in each class of the factors; and the weights of evidence method, which extends the previous technique to include both positive and negative evidence of landslide occurrence in the estimation of weights for the classes. One key aspect during the hazard evaluation was the decision on the methodology to be chosen for the final assessment. Instead of opting for a single methodology, it was decided to combine the results of the three implemented techniques using a combination rule based on a normalization of the results of each method. The hazard evaluation was performed for both earthquake- and rainfall-induced landslides. The country chosen for the drill-down exercise was El Salvador. The results indicate that highest hazard levels are concentrated along the central volcanic chain and at the centre of the northern mountains.

  4. Landslide Hazard Analysis with Multidisciplinary Approach: İstanbul example (United States)

    Kılıç, Osman; Baş, Mahmut; Yahya Menteşe, Emin; Tarih, Ahmet; Duran, Kemal; Gümüş, Salim; Rıza Yapar, Evrens; Emin Karasu, Muhammed; Acar Kara, Sema; Karaman, Abdullah; Özalaybey, Serdar; Zor, Ekrem; Ediger, Vedat; Arpat, Esen; Özgül, Necdet; Polat, Feyzi; Doǧan, Uǧur; Çakır, Ziyadin


    There are several methods that can be utilized for describing the landslide mechanisms. While some of them are commonly used, there are relatively new methods that have been proven to be useful. Obviously, each method has its own limitations and thus integrated use of these methods contributes to obtaining a realistic landslide model. The slopes of Küçükçekmece and Büyükçekmece Lagoons located at the Marmara Sea coast of İstanbul, Turkey, are among most specific examples of complex type landslides. The landslides in the area started developing at low sea level, and appears to ceased or at least slowed down to be at minimum after the sea level rise, as oppose to the still-active landslides that continue to cause damage especially in the valley slopes above the recent sea level between the two lagoons. To clarify the characteristics of these slope movements and classify them in most accurate way, Directorate of Earthquake and Ground Research of Istanbul Metropolitan Municipality launched a project in cooperation with Marmara Research Center of The Scientific and Technological Research Council of Turkey (TÜBİTAK). The project benefits the utility of the techniques of different disciplines such as geology, geophysics, geomorphology, hydrogeology, geotechnics, geodesy, remote sensing and meteorology. The observations include detailed mapping of topography by airborne LIDAR, deformation monitoring with more than 80 GPS stations, Ground Based Synthetic Aperture Radar measurements in 8 critical zones, 81 geological drills and more than 20 km of geophysical measurements. With three years of monitoring, the acquired data, and the results such as landslide hazard map, were integrated in GIS database for the purpose of easing tasks for the urban planners and the decision makers.

  5. Landslides triggered by the 1946 Ancash earthquake, Peru (United States)

    Kampherm, T. S.; Evans, S. G.; Valderrama Murillo, P.


    The 1946 M7.3 Ancash Earthquake triggered a large number of landslides in an epicentral area that straddled the Continental Divide of South America in the Andes of Peru. A small number of landslides were described in reconnaissance reports by E. Silgado and Arnold Heim published shortly after the earthquake, but further details of the landslides triggered by the earthquake have not been reported since. Utilising field traverses, aerial photograph interpretation and GIS, our study mapped 45 landslides inferred to have been triggered by the event. 83% were rock avalanches involving Cretaceous limestones interbedded with shales. The five largest rock/debris avalanches occurred at Rio Llama (est. vol. 37 M m3), Suytucocha (est. vol., 13.5 Mm3), Quiches (est. vol. 10.5 Mm3 ), Pelagatos (est. vol. 8 Mm3), and Shundoy (est. vol. 8 Mm3). The Suytucocha, Quiches, and Pelagatos landslides were reported by Silgado and Heim. Rock slope failure was most common on slopes with a southwest aspect, an orientation corresponding to the regional dip direction of major planar structures in the Andean foreland belt (bedding planes and thrust faults). In valleys oriented transverse to the NW-SE structural grain of the epicentral area, south-westerly dipping bedding planes combined with orthogonal joint sets to form numerous wedge failures. Many initial rock slope failures were transformed into rock/debris avalanches by the entrainment of colluvium in their path. At Acobamba, a rock avalanche that transformed into a debris avalanche (est. vol. 4.3 Mm3) overwhelmed a village resulting in the deaths of 217 people. The cumulative volume-frequency plot shows a strong power law relation below a marked rollover, similar in form to that derived for landslides triggered by the 1994 Northridge Earthquake. The total volume of the 45 landslides is approximately 93 Mm3. The data point for the Ancash Earthquake plots near the regression line calculated by Keefer (1994), and modified by Malamud et al

  6. Landslide hazard in the Nebrodi Mountains (Northeastern Sicily) (United States)

    Cubito, A.; Ferrara, V.; Pappalardo, G.


    The eastern sector of the Nebrodi Mountains (NE Sicily), a part of the Apenninic-Maghrebian orogenic chain, is characterized by an high landslide hazard. The village of S. Domenica Vittoria, which lies in the area, has been particularly affected by various landslide phenomena, with resulting damage to buildings and infrastructure. The rocks outcropping in the area belong to the Cretaceous Monte Soro Flysch; they consist of an alternation of argillaceous and calcareous beds at the base and argillaceous and quartzarenitic beds at the top. The lithotechnical characteristics of the formation and the steepness of the slopes in the area lead to an elevated instability, as testified by the widespread occurrence of sub-vertical arcuate cliffs (landslide scarps) and sub-horizontal areas (landslide terraces), typical of a landslide-controlled morphology. From a kinematics point of view, the observed phenomena can be referred to multiple rotational slides, flows, and complex landslides, often with a retrogressive development and enlargement. Triggering causes lie principally in the intense rainfalls that determine the decay of the geomechanical properties of the terrain and supply discontinuos groundwater circulation that is evident in seasonal springs. Human activity, such as the construction of roads and buildings on steep slopes and dispersal of water from supply systems and sewers has a significant impact as well. Due to the instability of the area, expansion of the village, which is already limited by the morphological conditions, is made difficult by the high hazard level, especially in the areas at higher elevations, where the principal landslide scarps are located, and even more on the rims of the scarps. Considering the high hazard level, S. Domenica Vittoria has been inserted by the National Geological Service among the sites in Sicily to be monitored by means of a GPS network. The survey carried out along the entire slope hosting the village has furnished the base

  7. Wireless Sensing Node Network Management for Monitoring Landslide Disaster

    International Nuclear Information System (INIS)

    Takayama, S; Akiyama, J; Fujiki, T; Mokhtar, N A B


    This paper shows the network management and operation to monitor landslide disaster at slop of mountain and hill. Natural disasters damage a measuring system easily. It is necessary for the measuring system to be flexible and robust. The measuring network proposed in this paper is the telemetry system consisted of host system (HS) and local sensing nodes network system (LSNNS). LSNNS operates autonomously and sometimes is controlled by commands from HS. HS collects data/information of landslide disaster from LSNNS, and controls LSNNS remotely. HS and LSNNS are communicated by using 'cloud' system. The dual communication is very effective and convenient to manage a network system operation

  8. Rainfall-threshold conditions for landslides in a humid-tropical system (United States)

    Larsen, Matthew C.; Simon, Andrew


    Landslides are triggered by factors such as heavy rainfall, seismic activity, and construction on hillslopes. The leading cause of landslides in Puerto Rico is intense and/or prolonged rainfall. A rainfall threshold for rainfall-triggered landsliding is delimited by 256 storms that occurred between 1959 and 1991 in the central mountains of Puerto Rico, where mean annual rainfall is close to or in excess of 2,000 mm. Forty one of the 256 storms produced intense and/or prolonged rainfall that resulted in tens to hundreds of landslides. A threshold fitted to the lower boundary of the field defined by landslide-triggering storms is expressed as

  9. A cusp catastrophe model of mid-long-term landslide evolution over low latitude highlands of China (United States)

    Tao, Yun; Cao, Jie; Hu, Jinming; Dai, Zhicheng


    Based on a model describing a certain landslide case and catastrophe theory, we derived a cusp catastrophe model and corresponding inversion method to study mid-long-term landslide evolution. According to data of landslides, precipitation, and socioeconomic development from 1976 to 2008, the cusp catastrophe model describing this landslide evolution across a low-latitude highland area in China is obtained with the least squares method. Results of the model indicate that human activity determines landslide intensity. Local precipitation also impacts yearly landslide intensity to some extent, and controls the time when a strong and abrupt change in landslides occurs. During the period 1976-2008, there was an abrupt decrease of landslide intensity during 1994-1995, and an abrupt increase during 1995-1996. Since then, there have been frequent landslides in the low-latitude highland, with greater intensity. All these factors provide a scientific basis for formulating a contingency plan regarding landslide disasters.

  10. Drop Height and Volume Control the Mobility of Long-Runout Landslides on the Earth and Mars (United States)

    Johnson, Brandon C.; Campbell, Charles S.


    Long-runout landslides are landslides with volumes of 105 m3 or more, which move much farther from their source than expected. The observation that Martian landslides are generally less mobile than terrestrial landslides offers important evidence regarding the mechanism responsible for the high mobility of long-runout landslides. Here we simulate landslides as granular flow using a soft-particle discrete element model. We show that while surface gravity plays a negligible role, observed differences in fall height naturally reproduce the observed differences in mobility of Martian and terrestrial landslides. We also demonstrate that landslides on Iapetus may fit this trend. Our simulations do not include any fluid and indicate that a mechanism similar to acoustic fluidization can explain the high mobility of long-runout landslides. This implies that long-runout landslides on Mars should not be considered as evidence for ice, saturated clays, or liquid water.

  11. Improving Landslide Forecasting Using ASCAT-Derived Soil Moisture Data: A Case Study of the Torgiovannetto Landslide in Central Italy

    Directory of Open Access Journals (Sweden)

    Wolfgang Wagner


    Full Text Available Predicting the spatial and temporal occurrence of rainfall triggered landslides represents an important scientific and operational issue due to the high threat that they pose to human life and property. This study investigates the relationship between rainfall, soil moisture conditions and landslide movement by using recorded movements of a rock slope located in central Italy, the Torgiovannetto landslide. This landslide is a very large rock slide, threatening county and state roads. Data acquired by a network of extensometers and a meteorological station clearly indicate that the movements of the unstable wedge, first detected in 2003, are still proceeding and the alternate phases of quiescence and reactivation are associated with rainfall patterns. By using a multiple linear regression approach, the opening of the tension cracks (as recorded by the extensometers as a function of rainfall and soil moisture conditions prior the occurrence of rainfall, are predicted for the period 2007–2009. Specifically, soil moisture indicators are obtained through the Soil Water Index, SWI, a product derived by the Advanced SCATterometer (ASCAT on board the MetOp (Meteorological Operational satellite and by an Antecedent Precipitation Index, API. Results indicate that the regression performance (in terms of correlation coefficient, r significantly enhances if an indicator of the soil moisture conditions is included. Specifically, r is equal to 0.40 when only rainfall is used as a predictor variable and increases to r = 0.68 and r = 0.85 if the API and the SWI are used respectively. Therefore, the coarse spatial resolution (25 km of satellite data notwithstanding, the ASCAT SWI is found to be very useful for the prediction of landslide movements on a local scale. These findings, although valid for a specific area, present new opportunities for the effective use of satellite-derived soil moisture estimates to improve landslide forecasting.

  12. Reactivation of slow-moving landslides by earthquakes, kinematics measurements and mechanical implications (United States)

    Lacroix, Pascal; Perfettini, Hugo; Berthier, Etienne; Taipe, Edu; Guillier, Bertrand


    Major earthquakes in mountainous areas often trigger landslides. The impact of earthquakes on slow-moving landslides is however not well constrained due to few co-seismic measurements of landslide motion. We document the first time-series of a landslide reactivation by an earthquake (Mw6.0, distance 20 km), using continuous GPS measurements over the Maca landslide (Peru). Our survey shows a coseismic response of the landslide of about 2 cm, followed by a relaxation period of 5 weeks during which postseismic slip is three times greater than the coseismic displacement itself. Our results confirm the coseismic activation of landslides and provide the first observation of a post seismic displacement. Finally, a multi-temporal survey using images from the very high resolution Pléiades optical satellite, allowed us to detect 9 active slow-moving landslides over the whole valley. Their pattern of motion show they have been reactivated by the same earthquake. We analyze this small but comprehensive database of landslides reactivated by the earthquake. We find that the landslide motion due to the earthquake is function of the shaking intensity, suggesting a friction at the basal interface dependent on the earthquake solicitation. These various observations are consistent with a mechanical model where slip on the landslide basal interface is governed by rate and state friction, analogous to the mechanics of creeping tectonic faults.

  13. Assessment of landslide distribution map reliability in Niigata prefecture - Japan using frequency ratio approach (United States)

    Rahardianto, Trias; Saputra, Aditya; Gomez, Christopher


    Research on landslide susceptibility has evolved rapidly over the few last decades thanks to the availability of large databases. Landslide research used to be focused on discreet events but the usage of large inventory dataset has become a central pillar of landslide susceptibility, hazard, and risk assessment. Indeed, extracting meaningful information from the large database is now at the forth of geoscientific research, following the big-data research trend. Indeed, the more comprehensive information of the past landslide available in a particular area is, the better the produced map will be, in order to support the effective decision making, planning, and engineering practice. The landslide inventory data which is freely accessible online gives an opportunity for many researchers and decision makers to prevent casualties and economic loss caused by future landslides. This data is advantageous especially for areas with poor landslide historical data. Since the construction criteria of landslide inventory map and its quality evaluation remain poorly defined, the assessment of open source landslide inventory map reliability is required. The present contribution aims to assess the reliability of open-source landslide inventory data based on the particular topographical setting of the observed area in Niigata prefecture, Japan. Geographic Information System (GIS) platform and statistical approach are applied to analyze the data. Frequency ratio method is utilized to model and assess the landslide map. The outcomes of the generated model showed unsatisfactory results with AUC value of 0.603 indicate the low prediction accuracy and unreliability of the model.

  14. State fusion entropy for continuous and site-specific analysis of landslide stability changing regularities (United States)

    Liu, Yong; Qin, Zhimeng; Hu, Baodan; Feng, Shuai


    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.

  15. Rainfall-induced landslides in Europe: hotspots and thresholds (Invited) (United States)

    Cepeda, J.; Jaedicke, C.; Nadim, F.; Kalsnes, B.


    This contribution presents preliminary results of the European project SafeLand. SafeLand is a large-scale integrating collaborative research project on landslide risks in Europe, funded by the Seventh Framework Programme for research and technological development (FP7) of the European Commission. SafeLand was launched in May 2009 and will run for three years. The project team, which comprises 27 institutions from 12 European countries, is coordinated by the International Centre for Geohazards (ICG) in Norway. SafeLand aims to develop and implement an integrated and comprehensive approach to help and guide decision-making in connection with mitigation of landslide risks. Quantifying the effects of global change (changes in demography and climate change) on evolution of landslide risk in Europe is one of the main goals of SafeLand. The methodologies are tested in selected hazard and risk "hotspots” in Europe, in turn improving knowledge, methodologies and integration strategies for the management of landslide risk. The present contribution is focused on two components of SafeLand: (1) the identification of landslide hazard and risk hotspots and (2) the estimation and assessment of rainfall thresholds for triggering of landslides. Hotspots of landslide hazard and risk were identified by an objective GIS-based analysis. The results show clearly where landslide pose the largest hazard in Europe and the objective approach allows a ranking of the countries by exposed area and population. In absolute numbers, Italy is the country with the highest amount of area and population exposed. Relative to absolute number of inhabitants and area, small alpine countries such as Lichtenstein and Montenegro score highest where as much as 40% of the population could be exposed. It is obvious that the type and quality of the input data are decisive for the quality of the results. Especially the estimation of extreme precipitation events needs improvement. These preliminary results are

  16. Chemical and isotopic composition of natural waters in the Jizuki-yama landslide area, Nagano Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Ryuma; Mashima, Kiyotaka; Koizumi, Naoji


    A large-scale landslide took place at a southeastern slope of Mt. Jizuki, Nagano Prefecture, on July 26, 1985. It has been said that landslide is closely related to the hydrological and hydrogeochemical nature of groundwater involved. To investigate the weathering mechanism and the origin of groundwater, we collected and analyzed water samples from the large-scale landslide area. The following facts can be pointed out: (1) weather-rock interaction is remarkably active in the landslide area, (2) most of the waters from the landslide area are in equilibrium with Na-montmorillonite (3) immediately after the landslide occurred bicarbonate and sodium ions are dominant, but sulfate and sodium ions become dominant with time, and (4) groundwater passing through horizontally drilled holes dose not effectively drain off to stabilize a slope in the landslide area. And our hypothesis on the mechanism for the formation of sodium sulfate type water is also presented.

  17. Frictional velocity-weakening in landslides on Earth and on other planetary bodies. (United States)

    Lucas, Antoine; Mangeney, Anne; Ampuero, Jean Paul


    One of the ultimate goals in landslide hazard assessment is to predict maximum landslide extension and velocity. Despite much work, the physical processes governing energy dissipation during these natural granular flows remain uncertain. Field observations show that large landslides travel over unexpectedly long distances, suggesting low dissipation. Numerical simulations of landslides require a small friction coefficient to reproduce the extension of their deposits. Here, based on analytical and numerical solutions for granular flows constrained by remote-sensing observations, we develop a consistent method to estimate the effective friction coefficient of landslides. This method uses a constant basal friction coefficient that reproduces the first-order landslide properties. We show that friction decreases with increasing volume or, more fundamentally, with increasing sliding velocity. Inspired by frictional weakening mechanisms thought to operate during earthquakes, we propose an empirical velocity-weakening friction law under a unifying phenomenological framework applicable to small and large landslides observed on Earth and beyond.

  18. Bay of Fundy (United States)


    The highest tides on Earth occur in the Minas Basin, the eastern extremity of the Bay of Fundy, Nova Scotia, Canada, where the tide range can reach 16 meters when the various factors affecting the tides are in phase. The primary cause of the immense tides of Fundy is a resonance of the Bay of Fundy-Gulf of Maine system. The system is effectively bounded at this outer end by the edge of the continental shelf with its approximately 40:1 increase in depth. The system has a natural period of approximately 13 hours, which is close to the 12h25m period of the dominant lunar tide of the Atlantic Ocean. Like a father pushing his daughter on a swing, the gentle Atlantic tidal pulse pushes the waters of the Bay of Fundy-Gulf of Maine basin at nearly the optimum frequency to cause a large to-and-fro oscillation. The greatest slosh occurs at the head (northeast end) of the system. The high tide image (top) was acquired April 20, 2001, and the low tide image (bottom) was acquired September 30, 2002. The images cover an area of 16.5 by 21 km, and are centered near 64 degrees west longitude and 45.5 degrees north latitude. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying

  19. Generating landslide inventory by participatory mapping: an example in Purwosari Area, Yogyakarta, Java (United States)

    Samodra, G.; Chen, G.; Sartohadi, J.; Kasama, K.


    This paper proposes an approach for landslide inventory mapping considering actual conditions in Indonesia. No satisfactory landslide database exists. What exists is inadequate, focusing, on data response, rather than on pre-disaster preparedness and planning. The humid tropical climate also leads a rapid vegetation growth so past landslides signatures are covered by vegetation or dismantled by erosion process. Generating landslide inventory using standard techniques still seems difficult. A catalog of disasters from local government (village level) was used as a basis of participatory landslide inventory mapping. Eyewitnesses or landslide disaster victims were asked to participate in the reconstruction of past landslides. Field investigation focusing on active participation from communities with the use of an innovative technology was used to verify the landslide events recorded in the disaster catalog. Statistical analysis was also used to obtain the necessary relationships between geometric measurements, including the height of the slope and length of run out, area and volume of displaced materials, the probability distributions of landslide area and volume, and mobilization rate. The result shows that run out distance is proportional to the height of the slope. The frequency distribution calculated by using non-cumulative distribution empirically exhibits a power law (fractal statistic) even though rollover can also be found in the dataset. This cannot be the result of the censoring effect or incompleteness of the data because the landslide inventory dataset can be classified as having complete data or nearly complete data. The so-called participatory landslide inventory mapping method is expected to solve the difficulties of landslide inventory mapping and can be applied to support pre-disaster planning and preparedness action to reduce the landslide disaster risk in Indonesia. It may also supplement the usually incomplete data in a typical landslide inventory.

  20. Influence of landslides on biophysical diversity — A perspective from British Columbia (United States)

    Geertsema, Marten; Pojar, James J.


    Landslides have long been overlooked or underestimated as important natural disturbance agents. In particular the ecological role of landslides in maintaining biological diversity has been largely ignored. Here we provide a western Canadian ( British Columbian) perspective on the influences of landslides on biophysical diversity, which is related in several ways to biological diversity. We recognize several types of biophysical/ecological diversity: site diversity, soil diversity, and the derivative habitat or ecosystem (including aquatic ecosystems) diversity. There are also a variety of landslide types, depending on materials and on the rate and style of movement. We discuss the roles of different landslide types on various aspects of terrestrial diversity. Landslides are simultaneously depositional and erosional processes that influence sites by redistributing materials and changing surface expression — usually creating a complex microtopography that can include very dry ridges and hummocks, and sometimes depressions with standing water. Landslide impacts to site also influence soil and soil development. Portions of landslides with exposed parent material are set back to the initial stages of soil development and ecological succession. Landslides can also change soil density, structure, porosity, surface texture, chemistry and microclimate. By changing site and soil, landslides also influence habitat. Landslides influence habitat diversity by engendering a mosaic of seral stages (often both primary and secondary), and in overwhelmingly forested landscapes often create nodes or hotspots of non-forested habitat and biota. In some areas, like the boreal forest, there is an important interplay between landslides and fire, while on the coast of British Columbia debris and snow avalanches can be the dominant disturbance agent. Low-gradient and deep-seated landslides are often opportunistically colonized by beaver and other water and shrub-loving fauna. Sag ponds and

  1. Land use change and landslide characteristics analysis for community-based disaster mitigation. (United States)

    Chen, Chien-Yuan; Huang, Wen-Lin


    On August 8, 2009, Typhoon Morakot brought heavy rain to Taiwan, causing numerous landslides and debris flows in the Taihe village area of Meishan Township, Chiayi County, in south-central Taiwan. In the Taihe land is primary used for agriculture and land use management may be a factor in the area's landslides. This study explores Typhoon Morakot-induced landslides and land use changes between 1999 and 2009 using GIS with the aid of field investigation. Spot 5 satellite images with a resolution of 2.5 m are used for landslide interpretation and manually digitalized in GIS. A statistical analysis for landslide frequency-area distribution was used to identify the landslide characteristics associated with different types of land use. There were 243 landslides with a total area of 2.75 km(2) in the study area. The area is located in intrinsically fragile combinations of sandstone and shale. Typhoon Morakot-induced landslides show a power-law distribution in the study area. Landslides were mainly located in steep slope areas containing natural forest and in areas planted with bamboo, tea, and betel nut. Land covered with natural forest shows the highest landslide ratio, followed by bamboo, betel nut, and tea. Landslides thus show a higher ratio in areas planted with shallow root vegetation such as bamboo, betel nut, and tea. Furthermore, the degree of basin development is proportional to the landslide ratio. The results show that a change in vegetation cover results in a modified landslide area and frequency and changed land use areas have higher landslide ratios than non-changed. Land use management and community-based disaster prevention are needed in mountainous areas of Taiwan for hazard mitigation.

  2. The 22 March 2014 Oso Landslide, Snohomish County, Washington: Findings of the GEER Reconnaissance Investigation (United States)

    Wartman, J.; Keaton, J. R.; Scott, A.; Benoit, J.; delaChapelle, J.; Gilbert, R.; Montgomery, D. R.


    We report the findings of the NSF-supported Geotechnical Extreme Events Reconnaissance (GEER) investigation of the Oso Landslide. Our findings are principally based on data collected during a four-day team reconnaissance across the entire landslide area, but also draw upon other data sources including lidar surveys, high-resolution imagery, geologic mapping, precipitation data, and seismic records. The Oso Landslide claimed 43 lives, making it the deadliest landslide disaster in U.S. history. The landslide occurred within a thick sequence of glacial sediments that were deposited into the North Fork Stillaguamish River valley during the last glacial advance. Geomorphic evidence suggests that the valley in the vicinity of Oso Landslide has experienced multiple large landslides over at least the past 6,000 years. Intense three-week rainfall that immediately preceded the event very probably played an important role in triggering the landslide; however, many other factors likely contributed to destabilization of the landslide mass. These include: (i) alteration of the local groundwater recharge and hydrogeological regime due to previous landsliding and, possibly, land use practices, (ii) weakening and alteration of the landslide mass due to previous landsliding and other natural geologic processes, and (iii) changes in stress distribution resulting from removal and deposition of material from earlier landsliding. During our field reconnaissance we identified six distinctive landslide zones and several subzones that are characterized by different geomorphic expression resulting from deformation styles, geologic materials, vegetation, and sequence of deposition. Based on the reconnaissance observations and other available data, we hypothesize that the landslide occurred in two major stages. The first stage of movement is interpreted to be a remobilization of the 2006 slide mass and headward extension that included part or all of the forested slope of an ancient landslide

  3. Reservoir-induced landslides and risk control in Three Gorges Project on Yangtze River, China

    Directory of Open Access Journals (Sweden)

    Yueping Yin


    Full Text Available The Three Gorges region in China was basically a geohazard-prone area prior to construction of the Three Gorges Reservoir (TGR. After construction of the TGR, the water level was raised from 70 m to 175 m above sea level (ASL, and annual reservoir regulation has caused a 30-m water level difference after impoundment of the TGR since September 2008. This paper first presents the spatiotemporal distribution of landslides in six periods of 175 m ASL trial impoundments from 2008 to 2014. The results show that the number of landslides sharply decreased from 273 at the initial stage to less than ten at the second stage of impoundment. Based on this, the reservoir-induced landslides in the TGR region can be roughly classified into five failure patterns, i.e. accumulation landslide, dip-slope landslide, reversed bedding landslide, rockfall, and karst breccia landslide. The accumulation landslides and dip-slope landslides account for more than 90%. Taking the Shuping accumulation landslide (a sliding mass volume of 20.7 × 106 m3 in Zigui County and the Outang dip-slope landslide (a sliding mass volume of about 90 × 106 m3 in Fengjie County as two typical cases, the mechanisms of reactivation of the two landslides are analyzed. The monitoring data and factor of safety (FOS calculation show that the accumulation landslide is dominated by water level variation in the reservoir as most part of the mass body is under 175 m ASL, and the dip-slope landslide is controlled by the coupling effect of reservoir water level variation and precipitation as an extensive recharge area of rainfall from the rear and the front mass is below 175 m ASL. The characteristics of landslide-induced impulsive wave hazards after and before reservoir impoundment are studied, and the probability of occurrence of a landslide-induced impulsive wave hazard has increased in the reservoir region. Simulation results of the Ganjingzi landslide in Wushan County indicate the

  4. USGS Tampa Bay Pilot Study (United States)

    Yates, K.K.; Cronin, T. M.; Crane, M.; Hansen, M.; Nayeghandi, A.; Swarzenski, P.; Edgar, T.; Brooks, G.R.; Suthard, B.; Hine, A.; Locker, S.; Willard, D.A.; Hastings, D.; Flower, B.; Hollander, D.; Larson, R.A.; Smith, K.


    Many of the nation's estuaries have been environmentally stressed since the turn of the 20th century and will continue to be impacted in the future. Tampa Bay, one the Gulf of Mexico's largest estuaries, exemplifies the threats that our estuaries face (EPA Report 2001, Tampa Bay Estuary Program-Comprehensive Conservation and Management Plan (TBEP-CCMP)). More than 2 million people live in the Tampa Bay watershed, and the population constitutes to grow. Demand for freshwater resources, conversion of undeveloped areas to resident and industrial uses, increases in storm-water runoff, and increased air pollution from urban and industrial sources are some of the known human activities that impact Tampa Bay. Beginning on 2001, additional anthropogenic modifications began in Tampa Bat including construction of an underwater gas pipeline and a desalinization plant, expansion of existing ports, and increased freshwater withdrawal from three major tributaries to the bay. In January of 2001, the Tampa Bay Estuary Program (TBEP) and its partners identifies a critical need for participation from the U.S. Geological Survey (USGS) in providing multidisciplinary expertise and a regional-scale, integrated science approach to address complex scientific research issue and critical scientific information gaps that are necessary for continued restoration and preservation of Tampa Bay. Tampa Bay stakeholders identified several critical science gaps for which USGS expertise was needed (Yates et al. 2001). These critical science gaps fall under four topical categories (or system components): 1) water and sediment quality, 2) hydrodynamics, 3) geology and geomorphology, and 4) ecosystem structure and function. Scientists and resource managers participating in Tampa Bay studies recognize that it is no longer sufficient to simply examine each of these estuarine system components individually, Rather, the interrelation among system components must be understood to develop conceptual and

  5. Landslides triggered by the 8 October 2005 Kashmir earthquake (United States)

    Owen, L.A.; Kamp, U.; Khattak, G.A.; Harp, E.L.; Keefer, D.K.; Bauer, M.A.


    The 8 October 2005 Kashmir earthquake triggered several thousand landslides. These were mainly rock falls and debris falls, although translational rock and debris slides also occurred. In addition, a sturzstrom (debris avalanche) comprising ??? 80??million m3 buried four villages and blocked streams to create two lakes. Although landsliding occurred throughout the region, covering an area of > 7500??km2, the failures were highly concentrated, associated with six geomorphic-geologic-anthropogenic settings, including natural failures in (1) highly fractured carbonate rocks comprising the lowest beds in the hanging wall of the likely earthquake fault; (2) Tertiary siliciclastic rocks along antecedent drainages that traverse the Hazara-Kashmir Syntaxis; (3) steep (> 50??) slopes comprising Precambrian and Lower Paleozoic rocks; (4) very steep (?? 50??) lower slopes of fluvially undercut Quaternary valley fills; and (5) ridges and spur crests. The sixth setting was associated with road construction. Extensive fissuring in many of the valley slopes together with the freshly mobilized landslide debris constitutes a potential hazard in the coming snowmelt and monsoon seasons. This study supports the view that earthquake-triggered landslides are highly concentrated in specific zones associated with the lithology, structure, geomorphology, topography, and human presence. ?? 2007 Elsevier B.V. All rights reserved.

  6. Spatially explicit shallow landslide susceptibility mapping over large areas (United States)

    Dino Bellugi; William E. Dietrich; Jonathan Stock; Jim McKean; Brian Kazian; Paul Hargrove


    Recent advances in downscaling climate model precipitation predictions now yield spatially explicit patterns of rainfall that could be used to estimate shallow landslide susceptibility over large areas. In California, the United States Geological Survey is exploring community emergency response to the possible effects of a very large simulated storm event and to do so...

  7. Landslides density map of S. Miguel Island, Azores archipelago (United States)

    Valadão, P.; Gaspar, J. L.; Queiroz, G.; Ferreira, T.

    The Azores archipelago is located in the Atlantic Ocean and is composed of nine volcanic islands. S. Miguel, the largest one, is formed by three active, E-W trending, trachytic central volcanoes with caldera (Sete Cidades, Fogo and Furnas). Chains of basaltic cinder cones link those major volcanic structures. An inactive trachytic central volcano (Povoação) and an old basaltic volcanic complex (Nordeste) comprise the easternmost part of the island. Since the settlement of the island early in the 15th century, several destructive landslides triggered by catastrophic rainfall episodes, earthquakes and volcanic eruptions occurred in different areas of S. Miguel. One unique event killed thousands of people in 1522. Houses and bridges were destroyed, roads were cut, communications, water and energy supply systems became frequently disrupted and areas of fertile land were often buried by mud. Based on (1) historical documents, (2) aerial photographs and (3) field observations, landslide sites were plotted on a topographic map, in order to establish a landslide density map for the island. Data obtained showed that landslide hazard is higher on (1) the main central volcanoes where the thickness of unconsolidated pyroclastic deposits is considerable high and (2) the old basaltic volcanic complex, marked by deep gullies developed on thick sequences of lava flows. In these areas, caldera walls, fault scarps, steep valley margins and sea cliffs are potentially hazardous.

  8. The seismic signatures of the 2009 Shiaolin landslide in Taiwan

    Directory of Open Access Journals (Sweden)

    Z. Feng


    Full Text Available The Shiaolin landslide occurred on 9 August 2009 after Typhoon Morakot struck Taiwan, claiming over 400 lives. The seismic signals produced by the landslide were recorded by broadband seismic stations in Taiwan. The time-frequency spectra for these signals were obtained by the Hilbert-Huang transform (HHT and were analyzed to obtain the seismic characteristics of the landslide. Empirical mode decomposition (EMD was applied to differentiate weak surface-wave signals from noise and to estimate the surface-wave velocities in the region. The surface-wave velocities were estimated using the fifth intrinsic mode function (IMF 5 obtained from the EMD. The spectra of the earthquake data were compared. The main frequency content of the seismic waves caused by the Shiaolin landslide were in the range of 0.5 to 1.5 Hz. This frequency range is smaller than the frequency ranges of other earthquakes. The spectral analysis of surface waves (SASW method is suggested for characterizing the shear-wave velocities of the strata in the region.

  9. Characterisation of weathered clayey soils responsible for shallow landslides

    Directory of Open Access Journals (Sweden)

    C. Meisina


    Full Text Available Shallow earth translational slides and earth flows, affecting colluvial soils derived by the weathering of the clayey bedrock, are a recurrent problem causing damage to buildings and roads in many areas of Apennines. The susceptibility assessment, e.g. slope stability models, requires the preliminary characterization of these superficial covers (lithology, geotechnical and hydraulic parameters. The aim of the work is to develop and test a methodology for the identification and mapping of weathered clayey soils responsible for shallow landslides. A test site in Northern Apennines (Province of Pavia was selected. Argillaceous and marly successions characterize the area. Shallow landslides occurred periodically due to high intensity rainfalls. Trench pits were used for the soil profile description (lithology, structure, grade of weathering, thickness and sampling. The main geological, topographic and geomorphologic parameters of shallow landslides were analysed. Field surveys were integrated with some geotechnical laboratory tests (index properties, suction and volumetric characteristic determination, methylene blue adsorption test, linear shrinkage, swell strain. Engineering geological zoning was carried out by grouping the superficial soils on the basis of the following attributes: topographic conditions (slope angle, landslide occurrence, lithology (grain size, geometry (thickness, lithology of the bedrock, hydrogeological and geotechnical characteristics. The resulting engineering-geological units (areas that may be regarded as homogeneous from the geomorphologic and engineering – geological point of view were analysed in terms of shallow slope instability.

  10. landslide hazard zonation around gilgel gibe-ii hydroelectric project

    African Journals Online (AJOL)

    Preferred Customer

    provide information on the landslide hazard zones present along the new road. ... past experience gained from the study of causative factors and their impact on ... characterized by steep hill slopes and deep valleys. .... parameters such as attitudes of discontinuities, ... This may need more time and money to apply for.

  11. Landslides Are Common In The Amazon Rainforests Of SE Peru (United States)

    Khanal, S. P.; Muttiah, R. S.; Janovec, J. P.


    The recent landslides in La Conchita, California, Mumbai, India, Ratnapura, Sri Lanka and Sugozu village, Turkey have dramatically illustrated prolonged rainfall on water induced change in soil shear stress. In these examples, the human footprint may have also erased or altered the natural river drainage from small to large scales. By studying patterns of landslides in natural ecosystems, government officials, policy makers, engineers, geologists and others may be better informed about likely success of prevention or amelioration programs in risk prone areas. Our study area in the Los Amigos basin in Amazon rainforests of Southeastern Peru, has recorded several hundred landslides. The area has no large human settlements. The basin is characterized by heavy rainfall, dense vegetation, river meander and uniform soils. Our objectives were: 1). Determine the spatial pattern of landslides using GIS and Remotely sensed data, 2). Model the statistical relationship between environmental variables and, 3). Evaluate influence of drainage on landscape and soil loss. GIS layers consisted of: 50cm aerial imagery, DEMs, digitized streams, soils, geology, rainfall from the TRMM satellite, and vegetation cover from the LANDSAT and MODIS sensors.

  12. Modeling of Landslides with the Material Point Method

    DEFF Research Database (Denmark)

    Andersen, Søren Mikkel; Andersen, Lars


    A numerical model for studying the dynamic evolution of landslides is presented. The numerical model is based on the Generalized Interpolation Material Point Method. A simplified slope with a house placed on top is analysed. An elasto-plastic material model based on the Mohr-Coulomb yield criterion...

  13. Modelling of Landslides with the Material-point Method

    DEFF Research Database (Denmark)

    Andersen, Søren; Andersen, Lars


    A numerical model for studying the dynamic evolution of landslides is presented. The numerical model is based on the Generalized Interpolation Material Point Method. A simplified slope with a house placed on top is analysed. An elasto-plastic material model based on the Mohr-Coulomb yield criterion...

  14. Large eruption-triggered ocean-island landslide at Tenerife

    DEFF Research Database (Denmark)

    Harris, P; Branney, M; Storey, Michael


    An extensive debris-avalanche deposit has been discovered on Cañadas volcano, Tenerife (Canary Islands). The onshore component of the 733 ± 3 ka Abona landslide deposit exposes classic block facies and mixed facies across 90 km2. Three lines of evidence together show that the avalanche was trigge......An extensive debris-avalanche deposit has been discovered on Cañadas volcano, Tenerife (Canary Islands). The onshore component of the 733 ± 3 ka Abona landslide deposit exposes classic block facies and mixed facies across 90 km2. Three lines of evidence together show that the avalanche...... was triggered by an ignimbrite-forming explosive eruption: (1) the deposit is enclosed by phonolitic ignimbrites and is draped by a Plinian fallout layer, all within a single eruption unit; (2) it contains prismatic-jointed pumice blocks that were hot during landslide emplacement, indicated by chilled rims...... and breadcrust surfaces; (3) these blocks yield the same 40Ar/39Ar date as the associated ignimbrite and fall deposit. Landslide hummocks dammed surface water, forming ephemeral lakes perched on the volcano flank. Phonolite dome growth destabilized the southeast sector of a mid-Pleistocene Cañadas caldera wall...

  15. Landslide risk assessment of a slope in Tijuana city, Mexico

    Directory of Open Access Journals (Sweden)

    Aldo Onel Oliva González


    Full Text Available Context: Risk reduction and prevention of disasters events produced by landslides on urban slopes, requires an integral assessment considering conditioning and triggering natural and human factors. Such an assessment is a valuable prevention and mitigation tool for communities under risk and also for authorities involved in the process. Method: In this research, a general methodology for the assessment of landslides on an urban slope was studied and applied, considering the relationship between hazard and physical vulnerability in the zone of study. Hazard was determined by probabilistic methods, whereas vulnerability of the exposed elements was obtained taking into account two kinds of buildings and their spatial distribution, their structural integrity state, their foundation depth and the unstable terrain probable mass volume. Results: Safety factors were obtained under allowable levels to warrant stability of the slope under study, and valuation factors of the qualitative analysis indicate that the slope is unstable and that requires urgent maintenance. This confirms and validates the high probability of occurrence in the zone, obtained from historic records. Conclusions: It was found that landslide risk in the slope is high due to the high probability of its occurrence, with three possible movement directions that may impact on several buildings located in the zone. Assessment constitutes a work tool for institutions and authorities related with risk reduction due to landslides, as a way of prevent and mitigate disaster prone events.

  16. Structural aspect on the Slano blato landslide (Slovenia

    Directory of Open Access Journals (Sweden)

    Ladislav Placer


    Full Text Available The active landslide Slano blato above Lokavec in the Vipava valley, Slovenia, is a complex phenomenon. The hinterland of the landslide consists of the large fossil block of Mala Gora that slid about 300 m down the slope of Mt. Čaven, and was tilted with respect to the slope. We presume that the corresponding failure surface is concavelyshaped. The block consist in its lower part of Eocene flysch beds and in its upper part of Triassic carbonate rocks that are thrust over the flysch. It is probable that due to gravitational slumping the flysch basement obtained a concave shape, that serves as a catchment structure for retaining the ground water. It slowly percolates throughthe crushed calcarenitic layers in flysch. According to available data the Slano blato was triggered in 1887 by earthworks, and in 2000 by natural erosion processes. The structural characteristics allow the assumption that movement occurs in crushed and weathered flysch beds that are percolated by a steady or periodical supply ofgroundwater from the structural reservoir in the Mala Gora fossil slumped block. Coexistence of the older structural and the younger active weathered material landslides can be observed also at other localities along the thrust front of the Trnovo and Hrušica (Nanos nappe. Especially interesting in this respect are the Razdrto and Strane landslides.

  17. Optimized Vibration Chamber for Landslide Sensory and Alarm System (United States)

    Ismail, Eliza Sabira Binti; Hadi Habaebi, Mohamed; Daoud, Jamal I.; Rafiqul Islam, Md


    Landslide is one of natural hazard that is not unfamiliar disaster in Malaysia. Malaysia has experienced this disaster many times since 1969. This natural hazard has become a major research concern for Malaysian government when many people were injured badly and even had been killed. Many previous research works published in the open literature aimed at designing a system that could detect landslide in early stage before the landslide becomes catastrophic. This paper presents the early works on a major work-in-progress landslide early warning system for Malaysian environment. The aim of this system is to develop the most efficiently reliable cost-effective system in which slight earth movements are monitored continuously. The challenge this work aims at is to work with a low budget system that produces efficient performance. Hence, the material used is off-the-shelf. Early design optimization results of the vibration sensor used is quite promising detecting the slightest faint tremors, which are amplified using the best vibration chamber available. It is shown that the choice of proper pipe length and diameter dimensions in combination to a gravel to exaggerate the produced higher sensitivity level noise of 5 dB.

  18. The late Little Ice Age landslide calamity in North Bohemia: Triggers, impacts and post-landslide development reconstructed from documentary data (case study of the Kozi vrch Hill landslide)

    Czech Academy of Sciences Publication Activity Database

    Raška, P.; Zábranský, V.; Brázdil, Rudolf; Lamková, J.


    Roč. 255, feb (2016), s. 95-107 ISSN 0169-555X Institutional support: RVO:67179843 Keywords : flysch carpathians * shallow landslides * rainfall intensity * duration control * climatic-change * central-europe * debris flows * czechia * state * Landslide reconstruction * Documentary data * Little Ice Age * North Bohemia Subject RIV: EH - Ecology, Behaviour Impact factor: 2.958, year: 2016

  19. Landslide susceptibility estimations in the Gerecse hills (Hungary). (United States)

    Gerzsenyi, Dávid; Gáspár, Albert


    Surface movement processes are constantly posing threat to property in populated and agricultural areas in the Gerecse hills (Hungary). The affected geological formations are mainly unconsolidated sediments. Pleistocene loess and alluvial terrace sediments are overwhelmingly present, but fluvio-lacustrine sediments of the latest Miocene, and consolidated Eocene and Mesozoic limestones and marls can also be found in the area. Landslides and other surface movement processes are being studied for a long time in the area, but a comprehensive GIS-based geostatistical analysis have not yet been made for the whole area. This was the reason for choosing the Gerecse as the focus area of the study. However, the base data of our study are freely accessible from online servers, so the used method can be applied to other regions in Hungary. Qualitative data was acquired from the landslide-inventory map of the Hungarian Surface Movement Survey and from the Geological Map of Hungary (1 : 100 000). Morphometric parameters derived from the SRMT-1 DEM were used as quantitative variables. Using these parameters the distribution of elevation, slope gradient, aspect and categorized geological features were computed, both for areas affected and not affected by slope movements. Then likelihood values were computed for each parameters by comparing their distribution in the two areas. With combining the likelihood values of the four parameters relative hazard values were computed for each cell. This method is known as the "empirical probability estimation" originally published by Chung (2005). The map created this way shows each cell's place in their ranking based on the relative hazard values as a percentage for the whole study area (787 km2). These values provide information about how similar is a certain area to the areas already affected by landslides based on the four predictor variables. This map can also serve as a base for more complex landslide vulnerability studies involving

  20. Effects of climate change on landslide hazard in Europe (Invited) (United States)

    Nadim, F.; Solheim, A.


    Landslides represent a major threat to human life, property and constructed facilities, infrastructure and natural environment in most mountainous and hilly regions of the world. As a consequence of climatic changes and potential global warming, an increase of landslide activity is expected in some parts of the world in the future. This will be due to increased extreme rainfall events, changes of hydrological cycles, meteorological events followed by sea storms causing coastal erosion and melting of snow and of frozen soils in the high mountains. During the past century, Europe experienced many fatalities and significant economic losses due to landslides. Since in many parts of Europe landslides are the most serious natural hazard, several recent European research projects are looking into the effects of climate change on the risk associated with landslides. Examples are the recently initiated SafeLand project, which looks into this problem across the continent, and GeoExtreme, which focused on Norway. The ongoing project SafeLand ( is a large, integrating project financed by the European Commission. It involves close to 30 organizations from 13 countries in Europe, and it looks into the effects of global change (mainly changes in demography and climate change) on the pattern of landslide risk in Europe. The SafeLand objectives are to (1) provide policy-makers, public administrators, researchers, scientists, educators and other stakeholders with improved harmonized framework and methodology for the assessment and quantification of landslide risk in Europe's regions; (2) evaluate the changes in risk pattern caused by climate change, human activity and policy changes; and (3) provide guidelines for choosing the most appropriate risk management strategies, including risk mitigation and prevention measures. To assess the changes in the landslide risk pattern in Norway over the next 50 years, the four-year integrated research project GeoExtreme (www

  1. Spatially explicit shallow landslide susceptibility mapping over large areas (United States)

    Bellugi, Dino; Dietrich, William E.; Stock, Jonathan D.; McKean, Jim; Kazian, Brian; Hargrove, Paul


    Recent advances in downscaling climate model precipitation predictions now yield spatially explicit patterns of rainfall that could be used to estimate shallow landslide susceptibility over large areas. In California, the United States Geological Survey is exploring community emergency response to the possible effects of a very large simulated storm event and to do so it has generated downscaled precipitation maps for the storm. To predict the corresponding pattern of shallow landslide susceptibility across the state, we have used the model Shalstab (a coupled steady state runoff and infinite slope stability model) which susceptibility spatially explicit estimates of relative potential instability. Such slope stability models that include the effects of subsurface runoff on potentially destabilizing pore pressure evolution require water routing and hence the definition of upslope drainage area to each potential cell. To calculate drainage area efficiently over a large area we developed a parallel framework to scale-up Shalstab and specifically introduce a new efficient parallel drainage area algorithm which produces seamless results. The single seamless shallow landslide susceptibility map for all of California was accomplished in a short run time, and indicates that much larger areas can be efficiently modelled. As landslide maps generally over predict the extent of instability for any given storm. Local empirical data on the fraction of predicted unstable cells that failed for observed rainfall intensity can be used to specify the likely extent of hazard for a given storm. This suggests that campaigns to collect local precipitation data and detailed shallow landslide location maps after major storms could be used to calibrate models and improve their use in hazard assessment for individual storms.

  2. Characterization of landslide dams in the San Juan province (Argentina) (United States)

    Penna, Ivanna; Longchamp, Celine; Derron, Marc-Henri; Jaboyedoff, Michel


    River blockages caused by landslide deposition are common phenomena in active mountain chains, influencing erosion-sedimentation patterns and acting as primary and secondary hazards. Regional scale analyses regarding their spatial distribution and morphometry allow establishing boundary conditions for their occurrence and stability, and determine differences among regions with different landscape and climatic conditions. Owing to the combination of endogenous and exogenous factors, landslide dams are frequent phenomena in the Andes. In the Argentinean NW and the Patagonian Andes, previous studies showed that stability of landslide dams determined by morphometric parameters generally matched satisfactorily with dam behavior, with some exceptions in which climatic component played an important role in dam longevity. Aiming to expand the knowledge of landslide dams in the Argentinean Andes, in this work we analyzed the stability of rock avalanche dams in the Pampeam flat slab subduction zone. In the study area, mountain dynamics creates suitable conditions for the occurrence of 34 rock avalanches with volumes up to 0.3 km3. They developed in deeply carved valleys (Cordillera) and Inter-thrust valleys (Precordillera). 22 impoundments of rivers resulted from channelized rock avalanches with long runouts (4-10 km) that blocked tributaries rivers, but most of them by rock avalanches that filled the valley bottom, with run up in the opposite slope and limited movement parallel to the valley axis. Most of the dams breached in unknown times, except for the last event that occurred on November 12th 2005. The quantification of morphometric parameters and contributing areas indicates the existence of dams with dimensionless blockage index above 2.75 (stable domain) and below 3.08 (instable domain). The Los Erizos dam in our study area and the Barrancas dam in the Patagonian Andes show that besides morphometric parameters, climatic conditions are decisive. Stable landslide dams

  3. Application of Physically based landslide susceptibility models in Brazil (United States)

    Carvalho Vieira, Bianca; Martins, Tiago D.


    Shallow landslides and floods are the processes responsible for most material and environmental damages in Brazil. In the last decades, some landslides events induce a high number of deaths (e.g. Over 1000 deaths in one event) and incalculable social and economic losses. Therefore, the prediction of those processes is considered an important tool for land use planning tools. Among different methods the physically based landslide susceptibility models having been widely used in many countries, but in Brazil it is still incipient when compared to other ones, like statistical tools and frequency analyses. Thus, the main objective of this research was to assess the application of some Physically based landslide susceptibility models in Brazil, identifying their main results, the efficiency of susceptibility mapping, parameters used and limitations of the tropical humid environment. In order to achieve that, it was evaluated SHALSTAB, SINMAP and TRIGRS models in some studies in Brazil along with the Geotechnical values, scales, DEM grid resolution and the results based on the analysis of the agreement between predicted susceptibility and the landslide scar's map. Most of the studies in Brazil applied SHALSTAB, SINMAP and to a lesser extent the TRIGRS model. The majority researches are concentrated in the Serra do Mar mountain range, that is a system of escarpments and rugged mountains that extends more than 1,500 km along the southern and southeastern Brazilian coast, and regularly affected by heavy rainfall that generates widespread mass movements. Most part of these studies used conventional topographic maps with scales ranging from 1:2000 to 1:50000 and DEM-grid resolution between 2 and 20m. Regarding the Geotechnical and hydrological values, a few studies use field collected data which could produce more efficient results, as indicated by international literature. Therefore, even though they have enormous potential in the susceptibility mapping, even for comparison

  4. Landslide Hazard Assessment In Mountaneous Area of Uzbekistan (United States)

    Nyazov, R. A.; Nurtaev, B. S.

    Because of the growth of population and caretaking of the flat areas under agricul- ture, mountain areas have been intensively mastered, producing increase of natural and technogenic processes in Uzbekistan last years. The landslides are the most dan- gerous phenomena and 7240 of them happened during last 40 years. More than 50 % has taken place in the term of 1991 - 2000 years. The situation is aggravated be- cause these regions are situated in zones, where disastrous earthquakes with M> 7 occurred in past and are expected in the future. Continuing seismic gap in Uzbek- istan during last 15-20 years and last disastrous earthquakes occurred in Afghanistan, Iran, Turkey, Greece, Taiwan and India worry us. On the basis of long-term observa- tions the criteria of landslide hazard assessment (suddenness, displacement interval, straight-line directivity, kind of residential buildings destruction) are proposed. This methodology was developed on two geographic levels: local (town scale) and regional (region scale). Detailed risk analysis performed on a local scale and extrapolated to the regional scale. Engineering-geologic parameters content of hazard estimation of landslides and mud flows also is divided into regional and local levels. Four degrees of danger of sliding processes are distinguished for compiling of small-scale, medium- and large-scale maps. Angren industrial area in Tien-Shan mountain is characterized by initial seismic intensity of 8-9 (MSC scale). Here the human technological activity (open-cast mining) has initiated the forming of the large landslide that covers more- over 8 square kilometers and corresponds to a volume of 800 billion cubic meters. In turn the landslide influence can become the source of industrial emergencies. On an example of Angren industrial mining region, the different scenarios on safety control of residing of the people and motion of transport, regulating technologies definition of field improvement and exploitation of mountain

  5. Plugs or flood-makers? the unstable landslide dams of eastern Oregon (United States)

    Safran, Elizabeth B.; O'Connor, Jim E.; Ely, Lisa L.; House, P. Kyle; Grant, Gordon E.; Harrity, Kelsey; Croall, Kelsey; Jones, Emily


    Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4–33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40–70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide

  6. Lavaca Bay 1985-1987 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Samples were collected from October 15, 1985 through June 12, 1987 in emergent marsh and non-vegetated habitats throughout the Lavaca Bay system to characterize...

  7. FL BAY SPECTROUT-DIET (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Juvenile spotted seatrout and other sportfish are being monitored annually over a 6-mo period in Florida Bay to assess their abundance over time relative to...

  8. Broadband analysis of landslides seismic signal : example of the Oso-Steelhead landslide and other recent events (United States)

    Hibert, C.; Stark, C. P.; Ekstrom, G.


    Landslide failures on the scale of mountains are spectacular, dangerous, and spontaneous, making direct observations hard to obtain. Measurement of their dynamic properties during runout is a high research priority, but a logistical and technical challenge. Seismology has begun to help in several important ways. Taking advantage of broadband seismic stations, recent advances now allow: (i) the seismic detection and location of large landslides in near-real-time, even for events in very remote areas that may have remain undetected, such as the 2014 Mt La Perouse supraglacial failure in Alaska; (ii) inversion of long-period waves generated by large landslides to yield an estimate of the forces imparted by the bulk accelerating mass; (iii) inference of the landslide mass, its center-of-mass velocity over time, and its trajectory.Key questions persist, such as: What can the short-period seismic data tell us about the high-frequency impacts taking place within the granular flow and along its boundaries with the underlying bedrock? And how does this seismicity relate to the bulk acceleration of the landslide and the long-period seismicity generated by it?Our recent work on the joint analysis of short- and long-period seismic signals generated by past and recent events, such as the Bingham Canyon Mine and the Oso-Steelhead landslides, provides new insights to tackle these issues. Qualitative comparison between short-period signal features and kinematic parameters inferred from long-period surface wave inversion helps to refine interpretation of the source dynamics and to understand the different mechanisms for the origin of the short-period wave radiation. Our new results also suggest that quantitative relationships can be derived from this joint analysis, in particular between the short-period seismic signal envelope and the inferred momentum of the center-of-mass. In the future, these quantitative relationships may help to constrain and calibrate parameters used in

  9. Recent results from Daya Bay

    Directory of Open Access Journals (Sweden)

    Chua Ming-chung


    Full Text Available Utilizing powerful nuclear reactors as antineutrino sources, high mountains to provide ample shielding from cosmic rays in the vicinity, and functionally identical detectors with large target volume for near-far relative measurement, the Daya Bay Reactor Neutrino Experiment has achieved unprecedented precision in measuring the neutrino mixing angle θ13 and the neutrino mass squared difference |Δm2ee|. I will report the latest Daya Bay results on neutrino oscillations and light sterile neutrino search.

  10. Development of potential map for landslides by comparing instability indices of various time periods (United States)

    Chiang, Jie-Lun; Tian, Yu-Qing; Chen, Yie-Ruey; Tsai, Kuang-Jung


    In recent years, extreme rainfall events occur frequently and induced serious landslides and debris flow disasters in Taiwan. The instability indices will differ when using landslide maps of different time periods. We analyzed the landslide records during the period year, 2008 2012, the landslide area contributed 0.42% 2.94% of the total watershed area, the 2.94% was caused by the typhoon Morakot in August, 2009, which brought massive rainfall in which the cumulative maximum rainfall was up to 2900 mm. We analyzed the instability factors including elevation, slope, aspect, soil, and geology. And comparing the instability indices by using individual landslide map of 2008 2012, the landslide maps of the union of the five years, and interaction of the five years. The landslide area from union of the five years contributed 3.71%,the landslide area from interaction of the five years contributed 0.14%. In this study, Kriging was used to establish the susceptibility map in selected watershed. From interaction of the five years, we found the instability index above 4.3 can correspond to those landslide records. The potential landslide area of the selected watershed, where collapses occur more likely, belongs to high level and medium-high level; the area is 13.43% and 3.04% respectively.

  11. An Improved Information Value Model Based on Gray Clustering for Landslide Susceptibility Mapping

    Directory of Open Access Journals (Sweden)

    Qianqian Ba


    Full Text Available Landslides, as geological hazards, cause significant casualties and economic losses. Therefore, it is necessary to identify areas prone to landslides for prevention work. This paper proposes an improved information value model based on gray clustering (IVM-GC for landslide susceptibility mapping. This method uses the information value derived from an information value model to achieve susceptibility classification and weight determination of landslide predisposing factors and, hence, obtain the landslide susceptibility of each study unit based on the clustering analysis. Using a landslide inventory of Chongqing, China, which contains 8435 landslides, three landslide susceptibility maps were generated based on the common information value model (IVM, an information value model improved by an analytic hierarchy process (IVM-AHP and our new improved model. Approximately 70% (5905 of the inventory landslides were used to generate the susceptibility maps, while the remaining 30% (2530 were used to validate the results. The training accuracies of the IVM, IVM-AHP and IVM-GC were 81.8%, 78.7% and 85.2%, respectively, and the prediction accuracies were 82.0%, 78.7% and 85.4%, respectively. The results demonstrate that all three methods perform well in evaluating landslide susceptibility. Among them, IVM-GC has the best performance.

  12. Floristic and vegetation successional processes within landslides in a Mediterranean environment. (United States)

    Neto, Carlos; Cardigos, Patrícia; Oliveira, Sérgio Cruz; Zêzere, José Luís


    Floristic and vegetation analysis in seven Mediterranean landslides led to the understanding of the successional processes occurring in different landslide disturbed sectors. Our study showed that in landslides that occurred between 1996 and 2010 there is a clear differentiation between the three main landslide sectors (scarp, main body and foot) concerning floristic composition, vegetation structure, floristic richness, successional processes and plant functional type. Additional differences were found between landslide areas and undisturbed agricultural areas adjacent to landslides. In this study 48 floristic relevés were made using a stratified random sampling design. The main landslide body exhibits the highest floristic richness whereas the landslide scarp has the lowest coverage rate and the highest presence of characteristic species from ruderal and strongly perturbed habitats. Finally, the landslide foot shows a late stage in the succession (maquis or pre-forest stage) with a high dominance of vines. We further discuss the importance of landslides as reservoirs of biodiversity especially for Mediterranean orchids. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Rainfall and earthquake-induced landslide susceptibility assessment using GIS and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Y. Li


    Full Text Available A GIS-based method for the assessment of landslide susceptibility in a selected area of Qingchuan County in China is proposed by using the back-propagation Artificial Neural Network model (ANN. Landslide inventory was derived from field investigation and aerial photo interpretation. 473 landslides occurred before the Wenchuan earthquake (which were thought as rainfall-induced landslides (RIL in this study, and 885 earthquake-induced landslides (EIL were recorded into the landslide inventory map. To understand the different impacts of rainfall and earthquake on landslide occurrence, we first compared the variations between landslide spatial distribution and conditioning factors. Then, we compared the weight variation of each conditioning factor derived by adjusting ANN structure and factors combination respectively. Last, the weight of each factor derived from the best prediction model was applied to the entire study area to produce landslide susceptibility maps.

    Results show that slope gradient has the highest weight for landslide susceptibility mapping for both RIL and EIL. The RIL model built with four different factors (slope gradient, elevation, slope height and distance to the stream shows the best success rate of 93%; the EIL model built with five different factors (slope gradient, elevation, slope height, distance to the stream and distance to the fault has the best success rate of 98%. Furthermore, the EIL data was used to verify the RIL model and the success rate is 92%; the RIL data was used to verify the EIL model and the success rate is 53%.

  14. Landslide susceptibility mapping using logistic statistical regression in Babaheydar Watershed, Chaharmahal Va Bakhtiari Province, Iran

    Directory of Open Access Journals (Sweden)

    Ebrahim Karimi Sangchini


    Full Text Available Landslides are amongst the most damaging natural hazards in mountainous regions. Every year, hundreds of people all over the world lose their lives in landslides; furthermore, there are large impacts on the local and global economy from these events. In this study, landslide hazard zonation in Babaheydar watershed using logistic regression was conducted to determine landslide hazard areas. At first, the landslide inventory map was prepared using aerial photograph interpretations and field surveys. The next step, ten landslide conditioning factors such as altitude, slope percentage, slope aspect, lithology, distance from faults, rivers, settlement and roads, land use, and precipitation were chosen as effective factors on landsliding in the study area. Subsequently, landslide susceptibility map was constructed using the logistic regression model in Geographic Information System (GIS. The ROC and Pseudo-R2 indexes were used for model assessment. Results showed that the logistic regression model provided slightly high prediction accuracy of landslide susceptibility maps in the Babaheydar Watershed with ROC equal to 0.876. Furthermore, the results revealed that about 44% of the watershed areas were located in high and very high hazard classes. The resultant landslide susceptibility maps can be useful in appropriate watershed management practices and for sustainable development in the region.

  15. Use of Satellite Remote Sensing Data in the Mapping of Global Landslide Susceptibility (United States)

    Hong, Yang; Adler, Robert F.; Huffman, George J.


    Satellite remote sensing data has significant potential use in analysis of natural hazards such as landslides. Relying on the recent advances in satellite remote sensing and geographic information system (GIS) techniques, this paper aims to map landslide susceptibility over most of the globe using a GIs-based weighted linear combination method. First , six relevant landslide-controlling factors are derived from geospatial remote sensing data and coded into a GIS system. Next, continuous susceptibility values from low to high are assigned to each of the six factors. Second, a continuous scale of a global landslide susceptibility index is derived using GIS weighted linear combination based on each factor's relative significance to the process of landslide occurrence (e.g., slope is the most important factor, soil types and soil texture are also primary-level parameters, while elevation, land cover types, and drainage density are secondary in importance). Finally, the continuous index map is further classified into six susceptibility categories. Results show the hot spots of landslide-prone regions include the Pacific Rim, the Himalayas and South Asia, Rocky Mountains, Appalachian Mountains, Alps, and parts of the Middle East and Africa. India, China, Nepal, Japan, the USA, and Peru are shown to have landslide-prone areas. This first-cut global landslide susceptibility map forms a starting point to provide a global view of landslide risks and may be used in conjunction with satellite-based precipitation information to potentially detect areas with significant landslide potential due to heavy rainfall. 1

  16. Mitigation of landslide area around railway tunnel, South Sumatra Province, Indonesia (United States)

    Toha, M. Taufik; Setiabudidaya, Dedi; Komar, Syamsul; Bochori, Ghadafi, Moamar A.; Adiwarman, Mirza; Rahim, S. E.


    Adequate and safe railway line infrastructures as well as facilities are required to support the rail transport system in South Sumatra. The slope stability along railway line of Lahat-Lubuk Linggau South Sumatra were studied during landslide that occured on January 23th, 2016. The landslide occurred on the mouth of railway tunnel in Gunung Gajah Village, Lahat District that causing the railway transportation system had to be stopped for a few days. A comprehensive research was conducted to analyze the causes of the landslide and to identify other landslide risky areas along the railway line Lahat-Lubuk Linggau. The research activities included surveying, sampling, laboratory testing, investigating condition of geology, geotechnics, hydrogeology/hydrology, morphology and land use. The factors that cause landslide in the past studies were found to be morphology, structural geology, physical and mechanical characteristics, hydrogeology, hydrology, external forces (train vibration, earthquake). Results back analysis of slope stability when the landslide occurred showed that the value Safety Factor (SF) = 1, angle of friction = 0°, and cohesion = 0.49 kg/cm2 (49 kPa). Based on the observation and analysis of the condition of the morphology and orientation of the structure of the rock layers, there was a location prone to landslide (labile) in the surrounding area of the landslide. Mitigations to potential landslide in adjacent area were building a retaining wall, draining channels, and shortcrete at the rock wall after landslides and maintaining the land use around the slopes.

  17. Landslides in everyday life: An interdisciplinary approach to understanding vulnerability in the Himalayas (United States)

    Sudmeier-Rieux, K.; Breguet, A.; Dubois, J.; Jaboyedoff, M.


    Several thousand landslides were triggered by the Kashmir earthquake, scarring the hillside with cracks. Monsoon rains continue to trigger landslides, which have increased the exposure of populations because of lost agricultural lands, blocked roads and annual fatalities due to landslides. The great majority of these landslides are shallow and relatively small but greatly impacting the population. In this region, landslides were a factor before the earthquake, mainly due to road construction and gravel excavation, but the several thousand landslides triggered by the earthquake have completely overwhelmed the local population and authorities. In Eastern Nepal, the last large earthquake to hit this region occurred in 1988, also triggering numerous landslides and cracks. Here, landslides can be considered a more common phenomenon, yet coping capacities amount to local observations of landslide movement, subsequent abandonment of houses and land as they become too dangerous. We present a comparative case study from Kashmir, Pakistan and Eastern Nepal, highlighting an interdisciplinary approach to understanding the complex interactions between land use, landslides and vulnerability. Our approach sets out to understand underlying causes of the massive landslides triggered by the 2005 earthquake in Kashmir, Pakistan, and also the increasing number of landslides in Nepal. By approaching the issue of landslides from multiple angles (risk perceptions, land use, local coping capacities, geological assessment, risk mapping) and multiple research techniques (remote sensing, GIS, geological assessment, participatory mapping, focus groups) we are better able to create a more complete picture of the "hazardscape". We find that by combining participatory social science research with hazard mapping, we obtain a more complete understanding of underlying causes, coping strategies and possible mitigation options, placing natural hazards in the context of everyday life. This method is

  18. Automatic Extraction and Size Distribution of Landslides in Kurdistan Region, NE Iraq

    Directory of Open Access Journals (Sweden)

    Arsalan A. Othman


    Full Text Available This study aims to assess the localization and size distribution of landslides using automatic remote sensing techniques in (semi- arid, non-vegetated, mountainous environments. The study area is located in the Kurdistan region (NE Iraq, within the Zagros orogenic belt, which is characterized by the High Folded Zone (HFZ, the Imbricated Zone and the Zagros Suture Zone (ZSZ. The available reference inventory includes 3,190 landslides mapped from sixty QuickBird scenes using manual delineation. The landslide types involve rock falls, translational slides and slumps, which occurred in different lithological units. Two hundred and ninety of these landslides lie within the ZSZ, representing a cumulated surface of 32 km2. The HFZ implicates 2,900 landslides with an overall coverage of about 26 km2. We first analyzed cumulative landslide number-size distributions using the inventory map. We then proposed a very simple and robust algorithm for automatic landslide extraction using specific band ratios selected upon the spectral signatures of bare surfaces as well as posteriori slope and the normalized difference vegetation index (NDVI thresholds. The index is based on the contrast between landslides and their background, whereas the landslides have high reflections in the green and red bands. We applied the slope threshold map to remove low slope areas, which have high reflectance in red and green bands. The algorithm was able to detect ~96% of the recent landslides known from the reference inventory on a test site. The cumulative landslide number-size distribution of automatically extracted landslide is very similar to the one based on visual mapping. The automatic extraction is therefore adapted for the quantitative analysis of landslides and thus can contribute to the assessment of hazards in similar regions.

  19. Criteria for the optimal selection of remote sensing optical images to map event landslides (United States)

    Fiorucci, Federica; Giordan, Daniele; Santangelo, Michele; Dutto, Furio; Rossi, Mauro; Guzzetti, Fausto


    Landslides leave discernible signs on the land surface, most of which can be captured in remote sensing images. Trained geomorphologists analyse remote sensing images and map landslides through heuristic interpretation of photographic and morphological characteristics. Despite a wide use of remote sensing images for landslide mapping, no attempt to evaluate how the image characteristics influence landslide identification and mapping exists. This paper presents an experiment to determine the effects of optical image characteristics, such as spatial resolution, spectral content and image type (monoscopic or stereoscopic), on landslide mapping. We considered eight maps of the same landslide in central Italy: (i) six maps obtained through expert heuristic visual interpretation of remote sensing images, (ii) one map through a reconnaissance field survey, and (iii) one map obtained through a real-time kinematic (RTK) differential global positioning system (dGPS) survey, which served as a benchmark. The eight maps were compared pairwise and to a benchmark. The mismatch between each map pair was quantified by the error index, E. Results show that the map closest to the benchmark delineation of the landslide was obtained using the higher resolution image, where the landslide signature was primarily photographical (in the landslide source and transport area). Conversely, where the landslide signature was mainly morphological (in the landslide deposit) the best mapping result was obtained using the stereoscopic images. Albeit conducted on a single landslide, the experiment results are general, and provide useful information to decide on the optimal imagery for the production of event, seasonal and multi-temporal landslide inventory maps.

  20. The Hollin Hill Landslide Observatory - a decade of geophysical characterization and monitoring (United States)

    Uhlemann, S.; Wilkinson, P. B.; Meldrum, P.; Smith, A.; Dixon, N.; Merritt, A.; Swift, R. T.; Whiteley, J.; Gunn, D.; Chambers, J. E.


    Landslides are major and frequent natural hazards. They shape the Earth's surface, and endanger communities and infrastructure worldwide. Within the last decade, landslides caused more than 28,000 fatalities and direct damage exceeding $1.8 billion. Climate change, causing more frequent weather extremes, is likely to increase occurrences of shallow slope failures worldwide. Thus, there is a need to improve our understanding of these shallow, rainfall-induced landslides. In this context, integrated geophysical characterization and monitoring can play a crucial role by providing volumetric data that can be linked to the hydrological and geotechnical conditions of a slope. This enables understanding of the complex hydrological processes most-often being associated with landslides. Here we present a review of a decade of characterizing and monitoring a complex, inland, clayey landslide - forming the "Hollin Hill Landslide Observatory". Within the last decade, this landslide has experienced different activity characteristics, including creep, flow, and rotational failures - thereby providing an excellent testbed for the development of geophysical and geotechnical monitoring instrumentation and methodologies. These include developments of 4D geoelectrical monitoring techniques to estimate electrode positions from the resistivity data, incorporating these into a time-lapse inversion, and imaging moisture dynamics that control the landslide behaviour. Other developments include acoustic emission monitoring, and active and passive seismic monitoring. This work is underpinned by detailed characterization of the landslide, using geomorphological and geological mapping, geotechnical investigations, and a thorough geoelectrical and seismic characterization of the landslide mass. Hence, the data gained from the Hollin Hill landslide observatory has improved our understanding of the shallow landslide dynamics in response to climate change, their mechanics and evolution. The

  1. Plan curvature and landslide probability in regions dominated by earth flows and earth slides (United States)

    Ohlmacher, G.C.


    Damaging landslides in the Appalachian Plateau and scattered regions within the Midcontinent of North America highlight the need for landslide-hazard mapping and a better understanding of the geomorphic development of landslide terrains. The Plateau and Midcontinent have the necessary ingredients for landslides including sufficient relief, steep slope gradients, Pennsylvanian and Permian cyclothems that weather into fine-grained soils containing considerable clay, and adequate precipitation. One commonly used parameter in landslide-hazard analysis that is in need of further investigation is plan curvature. Plan curvature is the curvature of the hillside in a horizontal plane or the curvature of the contours on a topographic map. Hillsides can be subdivided into regions of concave outward plan curvature called hollows, convex outward plan curvature called noses, and straight contours called planar regions. Statistical analysis of plan-curvature and landslide datasets indicate that hillsides with planar plan curvature have the highest probability for landslides in regions dominated by earth flows and earth slides in clayey soils (CH and CL). The probability of landslides decreases as the hillsides become more concave or convex. Hollows have a slightly higher probability for landslides than noses. In hollows landslide material converges into the narrow region at the base of the slope. The convergence combined with the cohesive nature of fine-grained soils creates a buttressing effect that slows soil movement and increases the stability of the hillside within the hollow. Statistical approaches that attempt to determine landslide hazard need to account for the complex relationship between plan curvature, type of landslide, and landslide susceptibility. ?? 2007 Elsevier B.V. All rights reserved.

  2. Earthquake induced landslide hazard field observatory in the Avcilar peninsula (United States)

    Bigarre, Pascal; Coccia, Stella; Theoleyre, Fiona; Ergintav, Semih; Özel, Oguz; Yalçinkaya, Esref; Lenti, Luca; Martino, Salvatore; Gamba, Paolo; Zucca, Francesco; Moro, Marco


    Earthquake-triggered landslides have an increasing disastrous impact in seismic regions due to the fast growing urbanization and infrastructures. Just considering disasters from the last fifteen years, among which the 1999 Chi-Chi earthquake, the 2008 Wenchuan earthquake, and the 2011 Tohoku earthquake, these events generated tens of thousands of coseismic landslides. Those resulted in amazing death toll and considerable damages, affecting the regional landscape including its hydrological main features. Despite a strong impetus in research during past decades, knowledge on those geohazards is still fragmentary, while databases of high quality observational data are lacking. These phenomena call for further collaborative researches aiming eventually to enhance preparedness and crisis management. The MARSITE project gathers research groups in a comprehensive monitoring activity developed in the Sea of Marmara Region, one of the most densely populated parts of Europe and rated at high seismic risk level since the 1999 Izmit and Duzce devastating earthquakes. Besides the seismic threat, landslides in Turkey and in this region constitute an important source of loss. The 6th Work Package of MARSITE project gathers 9 research groups to study earthquake-induced landslides focusing on two sub-regional areas of high interest among which the Cekmece-Avcilar peninsula, located westwards of Istanbul, as a highly urbanized concentrated landslide prone area, showing high susceptibility to both rainfalls while affected by very significant seismic site effects. A multidisciplinary research program based on pre-existing studies has been designed with objectives and tasks linked to constrain and tackle progressively some challenging issues related to data integration, modeling, monitoring and mapping technologies. Since the start of the project, progress has been marked on several important points as follows. The photogeological interpretation and analysis of ENVISAT-ERS DIn

  3. An application of adaptive neuro-fuzzy inference system to landslide susceptibility mapping (Klang valley, Malaysia) (United States)

    Sezer, Ebru; Pradhan, Biswajeet; Gokceoglu, Candan


    Landslides are one of the recurrent natural hazard problems throughout most of Malaysia. Recently, the Klang Valley area of Selangor state has faced numerous landslide and mudflow events and much damage occurred in these areas. However, only little effort has been made to assess or predict these events which resulted in serious damages. Through scientific analyses of these landslides, one can assess and predict landslide-susceptible areas and even the events as such, and thus reduce landslide damages through proper preparation and/or mitigation. For this reason , the purpose of the present paper is to produce landslide susceptibility maps of a part of the Klang Valley areas in Malaysia by employing the results of the adaptive neuro-fuzzy inference system (ANFIS) analyses. Landslide locations in the study area were identified by interpreting aerial photographs and satellite images, supported by extensive field surveys. Landsat TM satellite imagery was used to map vegetation index. Maps of topography, lineaments and NDVI were constructed from the spatial datasets. Seven landslide conditioning factors such as altitude, slope angle, plan curvature, distance from drainage, soil type, distance from faults and NDVI were extracted from the spatial database. These factors were analyzed using an ANFIS to construct the landslide susceptibility maps. During the model development works, total 5 landslide susceptibility models were obtained by using ANFIS results. For verification, the results of the analyses were then compared with the field-verified landslide locations. Additionally, the ROC curves for all landslide susceptibility models were drawn and the area under curve values was calculated. Landslide locations were used to validate results of the landslide susceptibility map and the verification results showed 98% accuracy for the model 5 employing all parameters produced in the present study as the landslide conditioning factors. The validation results showed sufficient

  4. Mathematical Modeling Applied to Prediction of Landslides in Southern Brazil (United States)

    Silva, Lúcia; Araújo, João; Braga, Beatriz; Fernandes, Nelson


    Mass movements are natural phenomena that occur on the slopes and are important agents working in landscape development. These movements have caused serious damage to infrastructure and properties. In addition to the mass movements occurring in natural slopes, there is also a large number of accidents induced by human action in the landscape. The change of use and land cover for the introduction of agriculture is a good example that have affected the stability of slopes. Land use and/or land cover changes have direct and indirect effects on slope stability and frequently represent a major factor controlling the occurrence of man-induced mass movements. In Brazil, especially in the southern and southeastern regions, areas of original natural rain forest have been continuously replaced by agriculture during the last decades, leading to important modifications in soil mechanical properties and to major changes in hillslope hydrology. In these regions, such effects are amplified due to the steep hilly topography, intense summer rainfall events and dense urbanization. In November 2008, a major landslide event took place in a rural area with intensive agriculture in the state of Santa Catarina (Morro do Baú) where many catastrophic landslides were triggered after a long rainy period. In this area, the natural forest has been replaced by huge banana and pine plantations. The state of Santa Catarina in recent decades has been the scene of several incidents of mass movements such as this catastrophic event. In this study, based on field mapping and modeling, we characterize the role played by geomorphological and geological factors in controlling the spatial distribution of landslides in the Morro do Baú area. In order to attain such objective, a digital elevation model of the basin was generated with a 10m grid in which the topographic parameters were obtained. The spatial distribution of the scars from this major event was mapped from another image, obtained immediately

  5. Numerical Modeling of the 2014 Oso, Washington, Landslide. (United States)

    George, D. L.; Iverson, R. M.


    Numerical simulations of alternative scenarios that could have transpired during the Oso, Washington, landslide of 22 March 2014 provide insight into factors responsible for the landslide's devastating high-speed runout.We performed these simulations using D-Claw, a numerical model we recently developed to simulate landslide and debris-flow motion from initiation to deposition. D-Claw solves a hyperbolic system of five partial differential equations that describe simultaneous evolution of the thickness,solid volume fraction, basal pore-fluid pressure, and two components of momentum of the moving mass. D-Claw embodies the concept ofstate-dependent dilatancy, which causes the solid volume fraction m to evolve toward a value that is equilibrated to the ambient stress state andshear rate. As the value of m evolves, basal pore-fluid pressure coevolves,and thereby causes an evolution in frictional resistance to motion. Our Oso simulations considered alternative scenarios in which values of all model parameters except the initial solid volume fraction m0 were held constant.These values were: basal friction angle = 36°; static critical-state solidvolume fraction = 0.64; initial sediment permeability = 10-8 m2; pore-fluid density = 1100 kg/m3; sediment grain density = 2700 kg/m3; pore-fluid viscosity = 0.005 Pa-s; and dimensionless sediment compressibility coefficient = 0.03. Simulations performed using these values and m0 = 0.62 produced widespread landslide liquefaction, runaway acceleration, andlandslide runout distances, patterns and speeds similar to those observed or inferred for the devastating Oso event. Alternative simulations that usedm0 = 0.64 produced a much slower landslide that did not liquefy and that traveled only about 100 m before stopping. This relatively benign behavioris similar to that of several landslides at the Oso site prior to 2014. Our findings illustrate a behavioral bifurcation that is highly sensitive to the initial solid volume fraction

  6. A Hybrid Physical and Maximum-Entropy Landslide Susceptibility Model

    Directory of Open Access Journals (Sweden)

    Jerry Davis


    Full Text Available The clear need for accurate landslide susceptibility mapping has led to multiple approaches. Physical models are easily interpreted and have high predictive capabilities but rely on spatially explicit and accurate parameterization, which is commonly not possible. Statistical methods can include other factors influencing slope stability such as distance to roads, but rely on good landslide inventories. The maximum entropy (MaxEnt model has been widely and successfully used in species distribution mapping, because data on absence are often uncertain. Similarly, knowledge about the absence of landslides is often limited due to mapping scale or methodology. In this paper a hybrid approach is described that combines the physically-based landslide susceptibility model “Stability INdex MAPping” (SINMAP with MaxEnt. This method is tested in a coastal watershed in Pacifica, CA, USA, with a well-documented landslide history including 3 inventories of 154 scars on 1941 imagery, 142 in 1975, and 253 in 1983. Results indicate that SINMAP alone overestimated susceptibility due to insufficient data on root cohesion. Models were compared using SINMAP stability index (SI or slope alone, and SI or slope in combination with other environmental factors: curvature, a 50-m trail buffer, vegetation, and geology. For 1941 and 1975, using slope alone was similar to using SI alone; however in 1983 SI alone creates an Areas Under the receiver operator Curve (AUC of 0.785, compared with 0.749 for slope alone. In maximum-entropy models created using all environmental factors, the stability index (SI from SINMAP represented the greatest contributions in all three years (1941: 48.1%; 1975: 35.3; and 1983: 48%, with AUC of 0.795, 0822, and 0.859, respectively; however; using slope instead of SI created similar overall AUC values, likely due to the combined effect with plan curvature indicating focused hydrologic inputs and vegetation identifying the effect of root cohesion

  7. Suppressing geo-facts in landslide-affected areas (United States)

    Sajinkumar, Ks; Pradeepkumar, Ap; Rani, Vr; Di Capua, Giuseppe


    The Western Ghats, the bold westerly escarpment of India and which borders the eastern portion of Kerala State (India), bears the testimony of frequent landslides, especially during the monsoon season, and they cause widespread damage to life and property. The natural hazards can turn into disasters in this hilly state, due to the high density of population (~800 per km2). The elements at landslide risk in any area include human population, livestock, land and its resources, environmental values, buildings and economic activities. The loss of lives is the most heart breaking side of the story and cannot be compensated in pecuniary terms. The role of the geoscientist comes into picture to protect the life and property from imminent landslides. But the unbiased role of a geoscientist is blocked by several societal issues like fear of disapproval by the public, political interference, false information propagated through the fourth estate and last but not the least the lack of confidence in her/himself as the profession is now mainly non-societal. This paper aims at looking into these issues in a landslide-prone area of the state. The deontological vs consequential ethical behaviours that characterise the responses by the official machinery and the common man conspire to create disastrous situations, which ultimately brings suffering to the common man, while straining the resources of the state through recurrent payment of damages, every year. The "moral vs monetary" values of society and its government is laid bare in Kerala, especially during landslide disasters and the state's social contract obligations sometimes become ambiguous. Another aspect that has to be addressed is the impact on the marginalized during landslide disasters in Kerala. Does the newly instituted 'Disaster Insurance' scheme adequately cover them? What is the ethical dimensions that such schemes address? The Kerala state is the most socially, educationally, and demographically advanced one in

  8. Landslide Probability Assessment by the Derived Distributions Technique (United States)

    Muñoz, E.; Ochoa, A.; Martínez, H.


    Landslides are potentially disastrous events that bring along human and economic losses; especially in cities where an accelerated and unorganized growth leads to settlements on steep and potentially unstable areas. Among the main causes of landslides are geological, geomorphological, geotechnical, climatological, hydrological conditions and anthropic intervention. This paper studies landslides detonated by rain, commonly known as "soil-slip", which characterize by having a superficial failure surface (Typically between 1 and 1.5 m deep) parallel to the slope face and being triggered by intense and/or sustained periods of rain. This type of landslides is caused by changes on the pore pressure produced by a decrease in the suction when a humid front enters, as a consequence of the infiltration initiated by rain and ruled by the hydraulic characteristics of the soil. Failure occurs when this front reaches a critical depth and the shear strength of the soil in not enough to guarantee the stability of the mass. Critical rainfall thresholds in combination with a slope stability model are widely used for assessing landslide probability. In this paper we present a model for the estimation of the occurrence of landslides based on the derived distributions technique. Since the works of Eagleson in the 1970s the derived distributions technique has been widely used in hydrology to estimate the probability of occurrence of extreme flows. The model estimates the probability density function (pdf) of the Factor of Safety (FOS) from the statistical behavior of the rainfall process and some slope parameters. The stochastic character of the rainfall is transformed by means of a deterministic failure model into FOS pdf. Exceedance probability and return period estimation is then straightforward. The rainfall process is modeled as a Rectangular Pulses Poisson Process (RPPP) with independent exponential pdf for mean intensity and duration of the storms. The Philip infiltration model

  9. Coseismic and postseismic motion of a landslide: Observations, modeling, and analogy with tectonic faults (United States)

    Lacroix, P.; Perfettini, H.; Taipe, E.; Guillier, B.


    We document the first time series of a landslide reactivation by an earthquake using continuous GPS measurements over the Maca landslide (Peru). Our survey shows a coseismic response of the landslide of about 2 cm, followed by a relaxation period of 5 weeks during which postseismic slip is 3 times greater than the coseismic displacement itself. Our results confirm the coseismic activation of landslides and provide the first observation of a postseismic displacement. These observations are consistent with a mechanical model where slip on the landslide basal interface is governed by rate and state friction, analogous to the mechanics of creeping tectonic faults, opening new perspectives to study the mechanics of landslides and active faults.

  10. Integrating Expert Knowledge with Statistical Analysis for Landslide Susceptibility Assessment at Regional Scale

    Directory of Open Access Journals (Sweden)

    Christos Chalkias


    Full Text Available 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.

  11. Landslide hazard assessment of the Black sea coastline (Caucasus, Russia) via drones (United States)

    Kazeev, Andrey; Postoev, German; Fedotova, Ksenia


    Landslide hazard assessment of slopes of Sochi was performed along the railway between the cities Tuapse and Adler (total length 103 km). The railway passes through the territory with active development of hazardous geological processes such as landslides, rock falls and debris-flows. By the beginning of 2016, 36 landslide sites were discovered along the railway (total length 34 km), 48 rock-fall sites (length 31 km), and 5 debris-flow sites (length 0.14 km). In recent years the intensification of deformations was observed. For instance, during previous 10 years (1996¬¬-2005) 28 sudden deformations occurred due to slope processes, which caused interruptions in traffic. And in the present decade (2006-2015), 72 deformations were recorded. High landslide activity and economic loss determined the necessity of complex investigations of engineering geological conditions of landslides development and causes of its intensification. The protection strategy development was needed to minimize negative consequences. Thus, the investigations of landslide situation along the railway "Tuapse - Adler" included the categorization of landslide sites by level of hazard, with risk assessment based on numerical criteria. Preliminary evaluation of landslide hazard for the railway was conducted via the analysis of archived engineering-geological documents. 13 of 36 landslide sites (total length 13 km) were selected, reflecting the variety and peculiarities of landslide displacements on slopes (both active and inactive sites). Visual field observations of landslide slopes using drone "DJI Phantom 4" were completed during the second stage of this investigation. High-resolution photographs of landslide cirques, cracks, scarp walls, vegetation features were obtained via drone, which would have been impossible to obtain from the ground in conditions of dense subtropical vegetation cover. Possible approaches to the landslide activity and hazard assessment were evaluated: slope stability

  12. The third hans cloos lecture. Urban landslides: Socioeconomic impacts and overview of mitigative strategies (United States)

    Schuster, R.L.; Highland, L.M.


    As a result of population pressures, hillsides in the world's urban areas are being developed at an accelerating rate. This development increases the risk for urban landslides triggered by rainfall or earthquake activity. To counter this risk, four approaches have been employed by landslide managers and urban planners: (1) restricting development in landslide-prone areas; (2) implementing and enforcing excavation, grading, and construction codes; (3) protecting existing developments by physical mitigation measures and (4) developing and installing monitoring and warning systems. Where they have been utilized, these approaches generally have been effective in reducing the risk due to landslide hazards. In addition to these practices, landslide insurance holds promise as a mitigative measure by reducing the financial impact of landslides on individual property owners. Until recently, however, such insurance has not been widely available and, where it is available, it is so expensive that it has been little used. ?? Springer-Verlag 2006.

  13. International year of planet earth 7. Oceans, submarine land-slides and consequent tsunamis in Canada (United States)

    Mosher, D.C.


    Canada has the longest coastline and largest continental margin of any nation in the World. As a result, it is more likely than other nations to experience marine geohazards such as submarine landslides and consequent tsunamis. Coastal landslides represent a specific threat because of their possible proximity to societal infrastructure and high tsunami potential; they occur without warning and with little time lag between failure and tsunami impact. Continental margin landslides are common in the geologic record but rare on human timescales. Some ancient submarine landslides are massive but more recent events indicate that even relatively small slides on continental margins can generate devastating tsunamis. Tsunami impact can occur hundreds of km away from the source event, and with less than 2 hours warning. Identification of high-potential submarine landslide regions, combined with an understanding of landslide and tsunami processes and sophisticated tsunami propagation models, are required to identify areas at high risk of impact.

  14. Effect of landslides on the structural characteristics of land-cover based on complex networks (United States)

    He, Jing; Tang, Chuan; Liu, Gang; Li, Weile


    Landslides have been widely studied by geologists. However, previous studies mainly focused on the formation of landslides and never considered the effect of landslides on the structural characteristics of land-cover. Here we define the modeling of the graph topology for the land-cover, using the satellite images of the earth’s surface before and after the earthquake. We find that the land-cover network satisfies the power-law distribution, whether the land-cover contains landslides or not. However, landslides may change some parameters or measures of the structural characteristics of land-cover. The results show that the linear coefficient, modularity and area distribution are all changed after the occurence of landslides, which means the structural characteristics of the land-cover are changed.

  15. Model slope infiltration experiments for shallow landslides early warning (United States)

    Damiano, E.; Greco, R.; Guida, A.; Olivares, L.; Picarelli, L.


    Occurrence of fast landslides has become more and more dangerous during the last decades, due to the increased density of settlements, industrial plants and infrastructures. Such problem is particularly worrying in Campania (Southern Italy), where the fast population growth led a diffuse building activity without planning: indeed, recent flowslides caused hundreds of victims and heavy damages to buildings, roads and other infrastructures. Large mountainous areas in Campania are mantled by loose pyroclastic granular soils up to a depth of a few meters from top soil surface. These soils have usually a grain size that falls in the domain of silty sands, including pumice interbeds (gravelly sands), with saturated hydraulic conductivities up to the order of 10-1 cm/min. Such deposits often cover steep slopes, which stability is guaranteed by the apparent cohesion due to suction under unsaturated conditions, that are the most common conditions for these slopes [Olivares and Picarelli, 2001]. Whereas rainfall infiltration causes soil to approach saturation, suction vanishes and slope failure may occur. Besides soil physical properties, landslide triggering is influenced by several factors, such as rainfall intensity, soil initial moisture and suction, slope inclination, boundary conditions. Whereas slope failure occurs with soil close to being saturated, landslide may develop in form of fast and destructive flowslide. Calibration of reliable mathematical models of such a complex phenomenon requires availability of experimental observations of the major variables of interest, such as soil moisture and suction, soil deformation and displacements, pore water pressure, during the entire process of infiltration until slope failure. Due to the sudden trigger and extremely rapid propagation of such type of landslides, such data sets are rarely available for natural slopes where flowslides occurred. As a consequence landslide risk assessment and early warning in Campania rely on

  16. Assessment of landslide risk using gis and statistical methods in kysuce region

    Directory of Open Access Journals (Sweden)

    Barančoková Mária


    Full Text Available The landslide susceptibility was assessed based on multivariation analysis. The input parameters were represented by lithology, land use, slope inclination and average annual precipitation. These parameters were evaluated as independent variables, and the existing landslides as dependent variables. The individual input parameters were reclassified and spatially adjusted. Spatial analysis resulted in 15 988 combinations of input parameters representing the homogeneous condition unit (HCU . Based on the landslide density within individual units, the HCU polygons have been classified according to landslide risk into stable, conditionally stable, conditionally stable and unstable (subdivided into low, medium and high landslide risk. A total of 2002 HCU s were affected by landslides, and the remaining 13 986 were not affected. The total HCU area affected by landslides is about 156.92 km2 (20.1%. Stable areas covered 623.01 km2 (79.8%, and conditionally stable areas covered 228.77 km2 (29.33% out of this area. Unstable areas were divided into three levels of landslide risk - low, medium and high risk. An area of 111.19 km2 (14.3% represents low landslide risk, medium risk 29.7 km2 (3.8% and 16.01 km2 (2% represents high risk. Since Zlín Formation lithological unit covers approximately one-third of the study area, it also influences the overall landslide risk assessment. This lithological formation covers the largest area within all landslide risk classes as well as in conditionally stable areas. The most frequent slope class was in the range of 14-19. The higher susceptibility of Zlín Formation to landslides is caused mainly by different geomorphological value of claystone and sandstone sequence. The higher share of claystone results in higher susceptibility of this formation to exogenous degradation processes.

  17. Climate-Induced Landsliding within the Larch Dominant Permafrost Zone of Central Siberia (United States)

    Kharuk, Viacheslav I.; Shushpanov, Alexandr S.; Im, Sergei T.; Ranson, Kenneth J.


    Climate impact on landslide occurrence and spatial patterns were analyzed within the larch-dominant communities associated with continuous permafrost areas of central Siberia. We used high resolution satellite imagery (i.e. QuickBird, WorldView) to identify landslide scars over an area of 62 000 km2. Landslide occurrence was analyzed with respect to climate variables (air temperature, precipitation, drought index SPEI), and Gravity Recovery and Climate Experiment satellite derived equivalent of water thickness anomalies (EWTA). Landslides were found only on southward facing slopes, and the occurrence of landslides increased exponentially with increasing slope steepness. Lengths of landslides correlated positively with slope steepness. The observed upper elevation limit of landslides tended to coincide with the tree line. Observations revealed landslides occurrence was also found to be strongly correlated with August precipitation (r = 0.81) and drought index (r = 0.7), with June-July-August soil water anomalies (i.e., EWTA, r = 0.68-0.7), and number of thawing days (i.e., a number of days with t (max) > 0 deg C; r = 0.67). A significant increase in the variance of soil water anomalies was observed, indicating that occurrence of landslides may increase even with a stable mean precipitation level. The key-findings of this study are (1) landslides occurrence increased within the permafrost zone of central Siberia in the beginning of the 21st century; (2) the main cause of increased landslides occurrence are extremes in precipitation and soil water anomalies; and (3) landslides occurrence are strongly dependent on relief features such as southward facing steep slopes.

  18. Preliminary Map of Landslide Deposits in the Mesa Verde National Park Area, Colorado (United States)

    Carrara, Paul E.


    This report presents a preliminary map of landslide deposits in the Mesa Verde National Park area (see map sheet) at a compilation scale of 1:50,000. Landslide is a general term for landforms produced by a wide variety of gravity-driven mass movements, including various types of flows, slides, topples and falls, and combinations thereof produced by the slow to rapid downslope transport of surficial materials or bedrock. The map depicts more than 200 landslides ranging in size from small (0.01 square miles) earthflows and rock slumps to large (greater than 0.50 square miles) translational slides and complex landslides (Varnes, 1978). This map has been prepared to provide a regional overview of the distribution of landslide deposits in the Mesa Verde area, and as such constitutes an inventory of landslides in the area. The map is suitable for regional planning to identify broad areas where landslide deposits and processes are concentrated. It should not be used as a substitute for detailed site investigations. Specific areas thought to be subject to landslide hazards should be carefully studied before development. Many of the landslides depicted on this map are probably stable as they date to the Pleistocene (approximately 1.8-0.011 Ma) and hence formed under a different climate regime. However, the recognition of these landslides is important because natural and human-induced factors can alter stability. Reduction of lateral support (by excavations or roadcuts), removal of vegetation (by fire or development), or an increase in pore pressure (by heavy rains) may result in the reactivation of landslides or parts of landslides.

  19. Role of land use change in landslide-related sediment fluxes in tropical mountain regions (United States)

    Guns, M.; Vanacker, V.; Demoulin, A.


    Tropical mountain regions are characterised by high denudation rates. Landslides are known to be recurrent phenomena in active mountain belts, but their contribution to the overall sedimentary fluxes is not yet well known. Previous studies on sedimentary cascades have mostly focused on natural environments, without considering the impact of human and/or anthropogenic disturbances on sedimentary budgets. In our work, we hypothesise that human-induced land use change might alter the sediment cascade through shifts in the landslide magnitude-frequency relationship. We have tested this assumption in the Virgen Yacu catchment (approximately 11km2), in the Ecuadorian Cordillera Occidental. Landslide inventories and land use maps were established based on a series of sequential aerial photos (1963, 1977, 1984 and 1989), a HR Landsat image (2001) and a VHR WorldView2 image (2010). Aerial photographs were ortho-rectified, and coregistred with the WorldView2 satellite image. Field campaigns were realised in 2010 and 2011 to collect field-based data on landslide type and geometry (depth, width and length). This allowed us to establish an empirical relationship between landslide area and volume, which was then applied to the landslide inventories to estimate landslide-related sediment production rates for various time periods. The contribution of landslides to the overall sediment flux of the catchment was estimated by comparing the landslide-related sediment production to the total sediment yield. The empirical landslide area-volume relationship established here for the Ecuadorian Andes is similar to that derived for the Himalayas. It suggests that landslides are the main source of sediment in this mountainous catchment. First calculations indicate that human-induced land use change alters the magnitude-frequency relationship through strong increase of small landslides.

  20. Object-oriented identification of forested landslides with derivatives of single pulse LiDAR data (United States)

    Van Den Eeckhaut, Miet; Kerle, Norman; Poesen, Jean; Hervás, Javier


    In contrast to the many studies that use expert-based analysis of LiDAR derivatives for landslide mapping in forested terrain, only few studies have attempted to develop (semi-)automatic methods for extracting landslides from LiDAR derivatives. While all these studies are pixel-based, it has not yet been tested whether object-oriented analysis (OOA) could be an alternative. This study investigates the potential of OOA using only single-pulse LiDAR derivatives, such as slope gradient, roughness and curvature to map landslides. More specifically, the focus is on both LiDAR data segmentation and classification of slow-moving landslides in densely vegetated areas, where spectral data do not allow accurate landslide identification. A multistage procedure has been developed and tested in the Flemish Ardennes (Belgium). The procedure consists of (1) image binarization and multiresolution segmentation, (2) classification of landslide parts (main scarps and landslide body segments) and non-landslide features (i.e. earth banks and cropland fields) with supervised support vector machines at the appropriate scale, (3) delineation of landslide flanks, (4) growing of a landslide body starting from its main scarp, and (5) final cleaning of the inventory map. The results obtained show that OOA using LiDAR derivatives allows recognition and characterization of profound morphologic properties of forested deep-seated landslides on soil-covered hillslopes, because more than 90% of the main scarps and 70% of the landslide bodies of an expert-based inventory were accurately identified with OOA. For mountainous areas with bedrock, on the other hand, creation of a transferable model is expected to be more difficult.

  1. Controls of earthquake faulting style on near field landslide triggering : the role of coseismic slip


    Tatard, Lucile; Grasso, J. R.


    We compare the spatial distributions of seven databases of landslides triggered by M-w=5.6-7.9 earthquakes, using distances normalized by the earthquake fault length. We show that the normalized landslide distance distributions collapse, i.e., the normalized distance distributions overlap whatever the size of the earthquake, separately for the events associated with dip-slip, buried-faulting earthquakes, and surface-faulting earthquakes. The dip-slip earthquakes triggered landslides at larger...

  2. Engineering-geophysical criteria for evaluating the development stages of landslides in loess rocks

    Energy Technology Data Exchange (ETDEWEB)

    Abdullayev, S K


    As a result of conducting geophysical observations on landslide slopes formed by loess rocks, with their artifical moistening, quantitiative engineering-geophysical criteria were obtained which characterize the basic stages of landslide development. The studies were conducted by surface methods of electrical resistance and seismometry conducted directly in the massif. According to the indicators of moisture content, state of comminution, compactness calculated with the help of geophysical parameters, the stage of preparation and movement of landslides are characterized.

  3. A spatial database for landslides in northern Bavaria: A methodological approach (United States)

    Jäger, Daniel; Kreuzer, Thomas; Wilde, Martina; Bemm, Stefan; Terhorst, Birgit


    Landslide databases provide essential information for hazard modeling, damages on buildings and infrastructure, mitigation, and research needs. This study presents the development of a landslide database system named WISL (Würzburg Information System on Landslides), currently storing detailed landslide data for northern Bavaria, Germany, in order to enable scientific queries as well as comparisons with other regional landslide inventories. WISL is based on free open source software solutions (PostgreSQL, PostGIS) assuring good correspondence of the various softwares and to enable further extensions with specific adaptions of self-developed software. Apart from that, WISL was designed to be particularly compatible for easy communication with other databases. As a central pre-requisite for standardized, homogeneous data acquisition in the field, a customized data sheet for landslide description was compiled. This sheet also serves as an input mask for all data registration procedures in WISL. A variety of "in-database" solutions for landslide analysis provides the necessary scalability for the database, enabling operations at the local server. In its current state, WISL already enables extensive analysis and queries. This paper presents an example analysis of landslides in Oxfordian Limestones in the northeastern Franconian Alb, northern Bavaria. The results reveal widely differing landslides in terms of geometry and size. Further queries related to landslide activity classifies the majority of the landslides as currently inactive, however, they clearly possess a certain potential for remobilization. Along with some active mass movements, a significant percentage of landslides potentially endangers residential areas or infrastructure. The main aspect of future enhancements of the WISL database is related to data extensions in order to increase research possibilities, as well as to transfer the system to other regions and countries.

  4. The comparison of landslide ratio-based and general logistic regression landslide susceptibility models in the Chishan watershed after 2009 Typhoon Morakot (United States)

    WU, Chunhung


    The research built the original logistic regression landslide susceptibility model (abbreviated as or-LRLSM) and landslide ratio-based ogistic regression landslide susceptibility model (abbreviated as lr-LRLSM), compared the performance and explained the error source of two models. The research assumes that the performance of the logistic regression model can be better if the distribution of landslide ratio and weighted value of each variable is similar. Landslide ratio is the ratio of landslide area to total area in the specific area and an useful index to evaluate the seriousness of landslide disaster in Taiwan. The research adopted the landside inventory induced by 2009 Typhoon Morakot in the Chishan watershed, which was the most serious disaster event in the last decade, in Taiwan. The research adopted the 20 m grid as the basic unit in building the LRLSM, and six variables, including elevation, slope, aspect, geological formation, accumulated rainfall, and bank erosion, were included in the two models. The six variables were divided as continuous variables, including elevation, slope, and accumulated rainfall, and categorical variables, including aspect, geological formation and bank erosion in building the or-LRLSM, while all variables, which were classified based on landslide ratio, were categorical variables in building the lr-LRLSM. Because the count of whole basic unit in the Chishan watershed was too much to calculate by using commercial software, the research took random sampling instead of the whole basic units. The research adopted equal proportions of landslide unit and not landslide unit in logistic regression analysis. The research took 10 times random sampling and selected the group with the best Cox & Snell R2 value and Nagelkerker R2 value as the database for the following analysis. Based on the best result from 10 random sampling groups, the or-LRLSM (lr-LRLSM) is significant at the 1% level with Cox & Snell R2 = 0.190 (0.196) and Nagelkerke R2

  5. Submarine landslides in the Santa Barbara Channel as potential tsunami sources

    Directory of Open Access Journals (Sweden)

    H. G. Greene


    Full Text Available Recent investigations using the Monterey Bay Aquarium Research Institutes (MBARI Remotely Operated Vehicles (ROVs 'Ventana' and 'Tiburon' and interpretation of MBARI's EM 300 30 kHz multibeam bathymetric data show that the northern flank of the Santa Barbara Basin has experienced massive slope failures. Of particular concern is the large (130 km2 Goleta landslide complex located off Coal Oil Point near the town of Goleta, that measures 14.6-km long extending from a depth of 90 m to nearly 574 m deep and is 10.5 km wide. We estimate that approximately 1.75 km3 has been displaced by this slide during the Holocene. This feature is a complex compound submarine landslide that contains both surfical slump blocks and mud flows in three distinct segments. Each segment is composed of a distinct head scarp, down-dropped head block and a slide debris lobe. The debris lobes exhibit hummocky topography in the central areas that appear to result from compression during down slope movement. The toes of the western and eastern lobes are well defined in the multibeam image, whereas the toe of the central lobe is less distinct. Continuous seismic reflection profiles show that many buried slide debris lobes exist and comparison of the deformed reflectors with ODP Drill Site 149, Hole 893 suggest that at least 200 000 years of failure have occurred in the area (Fisher et al., 2005a. Based on our interpretation of the multibeam bathymetry and seismic reflection profiles we modeled the potential tsunami that may have been produced from one of the three surfical lobes of the Goleta slide. This model shows that a 10 m high wave could have run ashore along the cliffs of the Goleta shoreline. Several other smaller (2 km2 and 4 km2 slides are located on the northern flank of the Santa Barbara Basin, both to the west and east of Goleta slide and on the Conception fan along the western flank of the basin. One slide, named the Gaviota slide, is 3.8 km2, 2.6 km long and 1

  6. Physical properties of Kentucky's AML landslides: Case studies analyzed

    International Nuclear Information System (INIS)

    Iannacchione, A.T.; Vallejo, L.E.


    Once an abandoned mined land (AML) landslide occurs and is identified as an emergency, engineers must rapidly implement a slope stabilization design. Correct slope remediation solutions are generally derived from well-executed geotechnical examinations. This paper summarizes a large body of geotechnical data compiled by the US office of Surface Mining Reclamation and Enforcement (OSM) from AML landslides in eastern Kentucky. Special attention is placed on the examination of subsurface failures, phreatic water levels, soil profiles, and soil composition information from numerous borehole exploration programs. Strength properties calculated from laboratory procedures and stability analysis techniques were also reviewed. Laboratory-determined soil shear strength values were found to be higher than those inferred from stability analysis. This suggests that postfailure determinations of the phreatic surface may be largely inappropriate when used in stability analysis or that laboratory-measured shear strengths are ineffective in replicating in situ colluvium/spoil slope properties

  7. The costal landslide from analogue experiments: perspectives and limitation (United States)

    Del Ventisette, C.; Nolesini, T.; Moretti, S.; Fanti, R.


    Understanding the triggering mechanism of coastal landslides (triggered and/or developed at air-water interface) and their evolution is fundamental to evaluate their hazard and, predicting the energy, the associated tsunami risk. The aim of this work is to verify the suitability of analogue modelling to understand the triggering mechanism and the evolution of landslide along the costal line. As a starting case study the Sciara del Fuoco (SdF), northwest flank of the volcanic island of Stromboli (Italy), was chosen. The analogue modelling technique has been proven to represent an useful tool to understand many geological processes, as it allows studying the progressive deformation, providing also useful indications about the role of distinct factors controlling the final deformation pattern. The models simulated at a first approximation the geological geometries observed at Stromboli, a composite volcano forming the northernmost island of the Aeolian Archipelago (Tyrrhenian Sea). The activity of Stromboli volcano is characterized by a persistent mild explosive activity at the summit craters sporadically interrupted by episodes of lava effusion and violent paroxysmal explosions as in 2002-2003 and in 2007. During the 2002 effusion a large landslide occurred on the SdF. The landslide caused a tsunami, which produced severe damages along the island shores. A series of analogue models was performed to investigate the influence of two different types of triggering mechanism and the behaviour of landslides both in air and air-water interface: 1) surface bulging due to the intrusion of a dike; 2) accumulation of material due to an uppermost landslide or due to opening of a new vent. The models, constructed in a Plexiglas tank, were scaled to the natural prototype following the geometrical, rheological, kinematical and dynamical similarities (e.g. Hubbert, 1937; Ramberg, 1981). The modelling material (Fontainbleau sand and rice) was sieved on a slope, inclination of which

  8. Geomorphic clues to the Martian volatile inventory: Landslides (United States)

    Pieri, D.; Kirkpatrick, A.


    Eight landslide locales were selected in Valles Marineris for preliminary geomorphological mapping. Four main suites of morphological features were identified. In four order outward from the head scarp they are: (1) large ridges in head area, transverse to movement direction, probably slump blocks or pieces of wall that fell or toppled, possibly backward rotated; (2) smaller ridges, convex toward distal edge of slides, many with lobate pattern, some possibly step like scarps rather than ridges; (3) thin, sheet like debris cover, forms discrete fan shaped lobe with edge scarps unconfined; and (4) low transverse, continuous ridges (possibly folds) found at distal edge of slides, where debris appears to have encountered obstructions (e.g., opposing canyon walls), but not all confined slides exhibit this feature. Any one landslide can possess all or some of these features. Slides in the western Valles Marineris are more complex and show more variety than those in the eastern part.

  9. High-throughput landslide modelling using computational grids (United States)

    Wallace, M.; Metson, S.; Holcombe, L.; Anderson, M.; Newbold, D.; Brook, N.


    Landslides are an increasing problem in developing countries. Multiple landslides can be triggered by heavy rainfall resulting in loss of life, homes and critical infrastructure. Through computer simulation of individual slopes it is possible to predict the causes, timing and magnitude of landslides and estimate the potential physical impact. Geographical scientists at the University of Bristol have developed software that integrates a physically-based slope hydrology and stability model (CHASM) with an econometric model (QUESTA) in order to predict landslide risk over time. These models allow multiple scenarios to be evaluated for each slope, accounting for data uncertainties, different engineering interventions, risk management approaches and rainfall patterns. Individual scenarios can be computationally intensive, however each scenario is independent and so multiple scenarios can be executed in parallel. As more simulations are carried out the overhead involved in managing input and output data becomes significant. This is a greater problem if multiple slopes are considered concurrently, as is required both for landslide research and for effective disaster planning at national levels. There are two critical factors in this context: generated data volumes can be in the order of tens of terabytes, and greater numbers of simulations result in long total runtimes. Users of such models, in both the research community and in developing countries, need to develop a means for handling the generation and submission of landside modelling experiments, and the storage and analysis of the resulting datasets. Additionally, governments in developing countries typically lack the necessary computing resources and infrastructure. Consequently, knowledge that could be gained by aggregating simulation results from many different scenarios across many different slopes remains hidden within the data. To address these data and workload management issues, University of Bristol particle


    Directory of Open Access Journals (Sweden)

    Diandong Ren


    Full Text Available On August 8, 2010 in the northwestern Chinese province of Gansu, rainstorm-triggered debris flow devastated the small county of Zhouqu. A modeling study, using a new multiple-phase scalable and extensible geo-fluid model, suggests that the cause is the result of an intersection of several events. These were a heavy rainstorm, not necessarily the result of global warming, which triggered the landslide and followed a drought that created surface cracks and crevasses; the geology of the region, notably the loess covering heavily weathered surface rock; and the bedrock damage, which deepened the surface crevasses, inflicted by the 7.9 magnitude Wenchuan earthquake of May 12, 2008. Deforestation and topsoil erosion also contribute. The modeling results underscore the urgency for a high priority program of re-vegetation of Zhouqu county, without which the region will remain exposed to future disastrous, “progressive bulking” type landslides.

  11. Polarimetric Scattering Properties of Landslides in Forested Areas and the Dependence on the Local Incidence Angle

    Directory of Open Access Journals (Sweden)

    Takashi Shibayama


    Full Text Available This paper addresses the local incidence angle dependence of several polarimetric indices corresponding to landslides in forested areas. Landslide is deeply related to the loss of human lives and their property. Various kinds of remote sensing techniques, including aerial photography, high-resolution optical satellite imagery, LiDAR and SAR interferometry (InSAR, have been available for landslide investigations. SAR polarimetry is potentially an effective measure to investigate landslides because fully-polarimetric SAR (PolSAR data contain more information compared to conventional single- or dual-polarization SAR data. However, research on landslide recognition utilizing polarimetric SAR (PolSAR is quite limited. Polarimetric properties of landslides have not been examined quantitatively so far. Accordingly, we examined the polarimetric scattering properties of landslides by an assessment of how the decomposed scattering power components and the polarimetric correlation coefficient change with the local incidence angle. In the assessment, PolSAR data acquired from different directions with both spaceborne and airborne SARs were utilized. It was found that the surface scattering power and the polarimetric correlation coefficient of landslides significantly decrease with the local incidence angle, while these indices of surrounding forest do not. This fact leads to establishing a method of effective detection of landslide area by polarimetric information.

  12. GIS and statistical analysis for landslide susceptibility mapping in the Daunia area, Italy (United States)

    Mancini, F.; Ceppi, C.; Ritrovato, G.


    This study focuses on landslide susceptibility mapping in the Daunia area (Apulian Apennines, Italy) and achieves this by using a multivariate statistical method and data processing in a Geographical Information System (GIS). The Logistic Regression (hereafter LR) method was chosen to produce a susceptibility map over an area of 130 000 ha where small settlements are historically threatened by landslide phenomena. By means of LR analysis, the tendency to landslide occurrences was, therefore, assessed by relating a landslide inventory (dependent variable) to a series of causal factors (independent variables) which were managed in the GIS, while the statistical analyses were performed by means of the SPSS (Statistical Package for the Social Sciences) software. The LR analysis produced a reliable susceptibility map of the investigated area and the probability level of landslide occurrence was ranked in four classes. The overall performance achieved by the LR analysis was assessed by local comparison between the expected susceptibility and an independent dataset extrapolated from the landslide inventory. Of the samples classified as susceptible to landslide occurrences, 85% correspond to areas where landslide phenomena have actually occurred. In addition, the consideration of the regression coefficients provided by the analysis demonstrated that a major role is played by the "land cover" and "lithology" causal factors in determining the occurrence and distribution of landslide phenomena in the Apulian Apennines.

  13. Controls on slow-moving landslides revealed by satellite and airborne InSAR (United States)

    Handwerger, Alexander L.; Fielding, Eric J.


    Landslides display a wide variety of behaviors ranging from slow persistent motion to rapid acceleration and catastrophic failure. Given the variety of possible behaviors, improvements to our understanding of landslide mechanics are critical for accurate predictions of landslide dynamics. To better constrain the mechanisms that control landslide motion, we use recent SAR data collected by Copernicus Sentinel-1A/B, NASA UAVSAR, JAXA ALOS-2, and DLR TerraSAR-X to quantify the time-dependent kinematics of over 200 slow-moving landslides in the Central and Northern California Coast Ranges. These landslides are ideally suited for InSAR investigations due to their size (up to 5 km in length and 0.5 km in width), persistent downslope motion with low velocities (m/yr), and sparse vegetation. We quantify the seasonal and multi-year changes in velocity driven by changes in precipitation and find that landslide velocity varies over both timescales. Over seasonal timescales, each landslide displays a period of acceleration that occurs within weeks of the onset of seasonal rainfall suggesting that motion is governed by precipitation-induced changes in pore-water pressure. We also examine the effects of multi-year climate variations (i.e., recent historic California drought and the possible wet period that began in late 2016) on the activity of landslides. We find that the drought has led to a decrease in annual displacement over the past several years and predict that a resurgence in annual displacement will occur with an increase in annual rainfall. Lastly, we use UAVSAR data acquired at 4 different look directions to quantify 3D surface displacement of multiple landslides and invert for their subsurface geometry (i.e. basal slip surface) using recently developed 3D mass conservation techniques. The application of NASA's UAVSAR data represents a major advance from previous InSAR studies on landslides in this region and provides one of the first 3D dataset that contains

  14. Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquakes (United States)

    Wdowinski, S.; Peng, Z.; Ferrier, K.; Lin, C. H.; Hsu, Y. J.; Shyu, J. B. H.


    Earthquakes, landslides, and tropical cyclones are extreme hazards that pose significant threats to human life and property. Some of the couplings between these hazards are well known. For example, sudden, widespread landsliding can be triggered by large earthquakes and by extreme rainfall events like tropical cyclones. Recent studies have also shown that earthquakes can be triggered by erosional unloading over 100-year timescales. In a NASA supported project, titled "Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquake", we study triggering relations between these hazard types. The project focuses on such triggering relations in Taiwan, which is subjected to very wet tropical storms, landslides, and earthquakes. One example for such triggering relations is the 2009 Morakot typhoon, which was the wettest recorded typhoon in Taiwan (2850 mm of rain in 100 hours). The typhoon caused widespread flooding and triggered more than 20,000 landslides, including the devastating Hsiaolin landslide. Six months later, the same area was hit by the 2010 M=6.4 Jiashian earthquake near Kaohsiung city, which added to the infrastructure damage induced by the typhoon and the landslides. Preliminary analysis of temporal relations between main-shock earthquakes and the six wettest typhoons in Taiwan's past 50 years reveals similar temporal relations between M≥5 events and wet typhoons. Future work in the project will include remote sensing analysis of landsliding, seismic and geodetic monitoring of landslides, detection of microseismicity and tremor activities, and mechanical modeling of crustal stress changes due to surface unloading.

  15. Analysis of the 2003 Varunawat Landslide, Uttarkashi, India using Earth Observation data (United States)

    Vinod Kumar, K.; Lakhera, R. C.; Martha, Tapas R.; Chatterjee, R. S.; Bhattacharya, A.


    Mass movements such as landslides in mountainous terrains are natural degradation processes and one of the most important landscape-building factors. Varunawat Parbat overlooking Uttarkashi town witnessed a series of landslides on 23 September 2003 and the debris slides and rock falls continued for 2 weeks. This landslide complex was triggered due to the incessant rainfall prior to the event, and its occurrence led to the blockage of the pilgrim route to Gangotri (source of the Ganges river) and evacuation of thousands of people to safer places. Though there was no loss of lives due to timely evacuation, heavy losses to the property were reported. High-resolution stereoscopic earth observation data were acquired after the incidence to study the landslide in detail with emphasis on the cause of the landslide and mode of failure. Areas along the road and below the Varunawat foothill region are mapped for landslide risk. It was found that the foothill region of the Varunawat Parbat was highly disturbed by man-made activities and houses are dangerously located below steep slopes. The potential zones for landslides along with the existing active and old landslides are mapped. These areas are critical and their treatment with priority is required in order to minimise further landslide occurrences.

  16. GIS-Based Integration of Subjective and Objective Weighting Methods for Regional Landslides Susceptibility Mapping

    Directory of Open Access Journals (Sweden)

    Suhua Zhou


    Full Text Available The development of landslide susceptibility maps is of great importance due to rapid urbanization. The purpose of this study is to present a method to integrate the subjective weight with objective weight for regional landslide susceptibility mapping on the geographical information system (GIS platform. The analytical hierarchy process (AHP, which is subjective, was employed to weight predictive factors’ contribution to landslide occurrence. The frequency ratio (FR method, which is objective, was used to derive subclasses’ frequency ratio with respect to landslides that indicate the relative importance of a subclass within each predictive factor. A case study was carried out at Tsushima Island, Japan, using a historical inventory of 534 landslides and seven predictive factors: elevation, slope, aspect, terrain roughness index (TRI, lithology, land cover and mean annual precipitation (MAP. The landslide susceptibility index (LSI was calculated using the weighted linear combination of factors’ weights and subclasses’ weights. The study area was classified into five susceptibility zones according to the LSI. In addition, the produced susceptibility map was compared with maps generated using the conventional FR and AHP method and validated using the relative landslide index (RLI. The validation result showed that the proposed method performed better than the conventional application of the FR method and AHP method. The obtained landslide susceptibility maps could serve as a scientific basis for urban planning and landslide hazard management.

  17. Landslide Change Detection Based on Multi-Temporal Airborne LiDAR-Derived DEMs

    Directory of Open Access Journals (Sweden)

    Omar E. Mora


    Full Text Available Remote sensing technologies have seen extraordinary improvements in both spatial resolution and accuracy recently. In particular, airborne laser scanning systems can now provide data for surface modeling with unprecedented resolution and accuracy, which can effectively support the detection of sub-meter surface features, vital for landslide mapping. Also, the easy repeatability of data acquisition offers the opportunity to monitor temporal surface changes, which are essential to identifying developing or active slides. Specific methods are needed to detect and map surface changes due to landslide activities. In this paper, we present a methodology that is based on fusing probabilistic change detection and landslide surface feature extraction utilizing multi-temporal Light Detection and Ranging (LiDAR derived Digital Elevation Models (DEMs to map surface changes demonstrating landslide activity. The proposed method was tested in an area with numerous slides ranging from 200 m2 to 27,000 m2 in area under low vegetation and tree cover, Zanesville, Ohio, USA. The surface changes observed are probabilistically evaluated to determine the likelihood of the changes being landslide activity related. Next, based on surface features, a Support Vector Machine (SVM quantifies and maps the topographic signatures of landslides in the entire area. Finally, these two processes are fused to detect landslide prone changes. The results demonstrate that 53 out of 80 inventory mapped landslides were identified using this method. Additionally, some areas that were not mapped in the inventory map displayed changes that are likely to be developing landslides.

  18. A new methodology for modeling of direct landslide costs for transportation infrastructures (United States)

    Klose, Martin; Terhorst, Birgit


    The world's transportation infrastructure is at risk of landslides in many areas across the globe. A safe and affordable operation of traffic routes are the two main criteria for transportation planning in landslide-prone areas. The right balancing of these often conflicting priorities requires, amongst others, profound knowledge of the direct costs of landslide damage. These costs include capital investments for landslide repair and mitigation as well as operational expenditures for first response and maintenance works. This contribution presents a new methodology for ex post assessment of direct landslide costs for transportation infrastructures. The methodology includes tools to compile, model, and extrapolate landslide losses on different spatial scales over time. A landslide susceptibility model enables regional cost extrapolation by means of a cost figure obtained from local cost compilation for representative case study areas. On local level, cost survey is closely linked with cost modeling, a toolset for cost estimation based on landslide databases. Cost modeling uses Landslide Disaster Management Process Models (LDMMs) and cost modules to simulate and monetize cost factors for certain types of landslide damage. The landslide susceptibility model provides a regional exposure index and updates the cost figure to a cost index which describes the costs per km of traffic route at risk of landslides. Both indexes enable the regionalization of local landslide losses. The methodology is applied and tested in a cost assessment for highways in the Lower Saxon Uplands, NW Germany, in the period 1980 to 2010. The basis of this research is a regional subset of a landslide database for the Federal Republic of Germany. In the 7,000 km² large Lower Saxon Uplands, 77 km of highway are located in potential landslide hazard area. Annual average costs of 52k per km of highway at risk of landslides are identified as cost index for a local case study area in this region. The

  19. Landslide displacement analysis based on fractal theory, in Wanzhou District, Three Gorges Reservoir, China

    Directory of Open Access Journals (Sweden)

    Lei Gui


    Full Text Available Slow moving landslide is a major disaster in the Three Gorges Reservoir area. It is difficult to compare the deformation among different parts of this kind of landslide through GPS measurements when the displacement of different monitoring points is similar in values. So far, studies have been seldom carried out to find out the information hidden behind those GPS monitoring data to solve this problem. Therefore, in this study, three landslides were chosen to perform landslide displacement analysis based on fractal theory. The major advantage of this study is that it has not only considered the values of the displacement of those GPS monitoring points, but also considered the moving traces of them. This allows to reveal more information from GPS measurements and to obtain a broader understanding of the deformation history on different parts of a unique landslide, especially for slow moving landslides. The results proved that using the fractal dimension as an indicator is reliable to estimate the deformation of each landslide and to represent landslide deformation on both spatial and temporal scales. The results of this study could make sense to those working on landslide hazard and risk assessment and land use planning.

  20. Neural Network-Based Model for Landslide Susceptibility and Soil Longitudinal Profile Analyses

    DEFF Research Database (Denmark)

    Farrokhzad, F.; Barari, Amin; Choobbasti, A. J.


    The purpose of this study was to create an empirical model for assessing the landslide risk potential at Savadkouh Azad University, which is located in the rural surroundings of Savadkouh, about 5 km from the city of Pol-Sefid in northern Iran. The soil longitudinal profile of the city of Babol......, located 25 km from the Caspian Sea, also was predicted with an artificial neural network (ANN). A multilayer perceptron neural network model was applied to the landslide area and was used to analyze specific elements in the study area that contributed to previous landsliding events. The ANN models were...... studies in landslide susceptibility zonation....

  1. Sensitive clay landslide detection and characterization in and around Lakelse Lake, British Columbia, Canada (United States)

    Geertsema, Marten; Blais-Stevens, Andrée; Kwoll, Eva; Menounos, Brian; Venditti, Jeremy G.; Grenier, Alain; Wiebe, Kelsey


    The Lakelse Lake area in northwestern British Columbia, Canada, has a long history, and prehistory, of rapid sensitive clay landslides moving on very low gradients. However, until now, many landslides have gone undetected. We use an array of modern tools to identify hitherto unknown or poorly known landslide deposits, including acoustic subbottom profiles, multibeam sonar, and LiDAR. The combination of these methods reveals not only landslide deposits, but also geomorphic and sedimentologic structures that give clues about landslide type and mode of emplacement. LiDAR and bathymetric data reveal the areal extent of landslide deposits as well as the orientation of ridges that differentiate between spreading and flowing kinematics. The subbottom profiles show two-dimensional structures of disturbed landslide deposits, including horst and grabens indicative of landslides classified as spreads. A preliminary computer tomography (CT) scan of a sediment core confirms the structures of one subbottom profile. We also use archival data from the Ministry of Transportation and Infrastructure and resident interviews to better characterize historic landslides.

  2. A multidimensional stability model for predicting shallow landslide size and shape across landscapes. (United States)

    Milledge, David G; Bellugi, Dino; McKean, Jim A; Densmore, Alexander L; Dietrich, William E


    The size of a shallow landslide is a fundamental control on both its hazard and geomorphic importance. Existing models are either unable to predict landslide size or are computationally intensive such that they cannot practically be applied across landscapes. We derive a model appropriate for natural slopes that is capable of predicting shallow landslide size but simple enough to be applied over entire watersheds. It accounts for lateral resistance by representing the forces acting on each margin of potential landslides using earth pressure theory and by representing root reinforcement as an exponential function of soil depth. We test our model's ability to predict failure of an observed landslide where the relevant parameters are well constrained by field data. The model predicts failure for the observed scar geometry and finds that larger or smaller conformal shapes are more stable. Numerical experiments demonstrate that friction on the boundaries of a potential landslide increases considerably the magnitude of lateral reinforcement, relative to that due to root cohesion alone. We find that there is a critical depth in both cohesive and cohesionless soils, resulting in a minimum size for failure, which is consistent with observed size-frequency distributions. Furthermore, the differential resistance on the boundaries of a potential landslide is responsible for a critical landslide shape which is longer than it is wide, consistent with observed aspect ratios. Finally, our results show that minimum size increases as approximately the square of failure surface depth, consistent with observed landslide depth-area data.

  3. Spatial probabilistic approach on landslide susceptibility assessment from high resolution sensors derived parameters

    International Nuclear Information System (INIS)

    Aman, S N A; Latif, Z Abd; Pradhan, B


    Landslide occurrence depends on various interrelating factors which consequently initiate to massive mass of soil and rock debris that move downhill due to the gravity action. LiDAR has come with a progressive approach in mitigating landslide by permitting the formation of more accurate DEM compared to other active space borne and airborne remote sensing techniques. The objective of this research is to assess the susceptibility of landslide in Ulu Klang area by investigating the correlation between past landslide events with geo environmental factors. A high resolution LiDAR DEM was constructed to produce topographic attributes such as slope, curvature and aspect. These data were utilized to derive second deliverables of landslide parameters such as topographic wetness index (TWI), surface area ratio (SAR) and stream power index (SPI) as well as NDVI generated from IKONOS imagery. Subsequently, a probabilistic based frequency ratio model was applied to establish the spatial relationship between the landslide locations and each landslide related factor. Factor ratings were summed up to obtain Landslide Susceptibility Index (LSI) to construct the landslide susceptibility map

  4. Frontally confined versus frontally emergent submarine landslides: A 3D seismic characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Frey-Martinez, Jose; Cartwright, Joe; James, David [3DLab. School of Earth, Ocean and Planetary Sciences, Cardiff University, P.O. Box 914, Cardiff CF10 3YE (United Kingdom)


    Three-dimensional (3D) seismic data from the continental margin offshore Israel (Eastern Mediterranean) have been used to analyse the compressional structures within the toe regions of two major buried submarine landslides: the ISC and the T20. Both landslides are developed within a Plio-Pleistocene slope succession composed predominately of claystones, limestones and siltstones. The high spatial resolution provided by the seismic data has allowed a detailed analysis of the geometries and deformational structures within the toe regions of the two landslides, and this has been used to develop a mechanical model for their development. Importantly, it has been recognised that submarine landslides may be divided into two main types according to their form of frontal emplacement: frontally confined and frontally emergent. In the former, the landslide undergoes a restricted downslope translation and does not overrun the undeformed downslope strata. In the latter, much larger downslope translation occurs because the landslide is able to ramp up from its original basal shear surface and translate in an unconfined manner over the seafloor. We propose that these two types of submarine landslides are end members of a continuum of gravity-driven slope failure processes, which extends from landslides where the headscarp is completely evacuated, to landslides where the material remains entirely within the headscarp. The differentiation of these two end members is of critical importance as their respective mechanisms of formation, downslope propagation and emplacement are significantly different, and hence need to be taken into consideration when analysing their respective kinematics. (author)

  5. Establish susceptibility and risk assessment models for rainfall-induced landslide: A case in Central Taiwan (United States)

    Wu, Chunhung; Huang, Jyuntai


    Most of the landslide cases in Taiwan were triggered by rainfall or earthquake events. The heavy rainfall in the typhoon seasons, from June to October, causes the landslide hazard more serious. Renai Towhship is of the most large landslide cases after 2009 Typhoon Morakot (from Aug. 5 to Aug. 10, 2009) in Taiwan. Around 2,744 landslides cases with the total landslide area of 21.5 km2 (landslide ratio =1.8%), including 26 large landslide cases, induced after 2009 Typhoon Morakot in Renai Towhship. The area of each large landslides case is more than 0.1 km2, and the area of the largest case is around 0.96 km2. 58% of large landslide cases locate in the area with metamorphosed sandstone. The mean slope of 26 large landslide cases ranges from 15 degree to 56 degree, and the accumulated rainfall during 2009 Typhoon Morakot ranges from 530 mm to 937 mm. Three methods, including frequency ratio method (abbreviated as FR), weights of evidence method (abbreviated as WOE), and logistic regression method (abbreviated as LR), are used in this study to establish the landslides susceptibility in the Renai Township, Nantou County, Taiwan. Eight landslide related-factors, including elevation, slope, aspect, geology, land use, distance to drainage, distance to fault, accumulation rainfall during 2009 Typhoon Morakot, are used to establish the landslide susceptibility models in this study. The landslide inventory after 2009 Typhoon Morakot is also used to test the model performance in this study. The mean accumulated rainfall in Renai Township during 2009 typhoon Morakot was around 735 mm with the maximum 1-hr, 3-hrs, and 6-hrs rainfall intensity of 44 mm/1-hr, 106 mm/3-hrs and 204 mm/6-hrs, respectively. The range of original susceptibility values established by three methods are 4.0 to 20.9 for FR, -33.8 to -16.1 for WOE, and -41.7 to 5.7 for LR, and the mean landslide susceptibility value are 8.0, -24.6 and 0.38, respectively. The AUC values are 0.815 for FR, 0.816 for WOE, and 0

  6. Total water content thresholds for shallow landslides, Outer Western Carpathians

    Czech Academy of Sciences Publication Activity Database

    Bil, M.; Andrašík, R.; Zahradníček, Pavel; Kubeček, J.; Sedonik, J.; Štěpánek, Petr


    Roč. 13, č. 2 (2016), s. 337-347 ISSN 1612-510X R&D Projects: GA ČR GA13-19831S; GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : data quality -control * debris flows * rainfall thresholds * equivalent * depth * failures * example * europe * model * Landslides * Threshold * Snowmelt * Time series * Antecedent rainfall * Outer Western Carpathians Subject RIV: EH - Ecology, Behaviour Impact factor: 3.657, year: 2016

  7. Evaluating performances of simplified physically based landslide susceptibility models. (United States)

    Capparelli, Giovanna; Formetta, Giuseppe; Versace, Pasquale


    Rainfall induced shallow landslides cause significant damages involving loss of life and properties. Prediction of shallow landslides susceptible locations is a complex task that involves many disciplines: hydrology, geotechnical science, geomorphology, and statistics. Usually to accomplish this task two main approaches are used: statistical or physically based model. This paper presents a package of GIS based models for landslide susceptibility analysis. It was integrated in the NewAge-JGrass hydrological model using the Object Modeling System (OMS) modeling framework. The package includes three simplified physically based models for landslides susceptibility analysis (M1, M2, and M3) and a component for models verifications. It computes eight goodness of fit indices (GOF) by comparing pixel-by-pixel model results and measurements data. Moreover, the package integration in NewAge-JGrass allows the use of other components such as geographic information system tools to manage inputs-output processes, and automatic calibration algorithms to estimate model parameters. The system offers the possibility to investigate and fairly compare the quality and the robustness of models and models parameters, according a procedure that includes: i) model parameters estimation by optimizing each of the GOF index separately, ii) models evaluation in the ROC plane by using each of the optimal parameter set, and iii) GOF robustness evaluation by assessing their sensitivity to the input parameter variation. This procedure was repeated for all three models. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia municipality. The analysis provided that among all the optimized indices and all the three models, Average Index (AI) optimization coupled with model M3 is the best modeling solution for our test case. This research was funded by PON Project No. 01_01503 "Integrated Systems for Hydrogeological Risk

  8. Assessing population exposure for landslide risk analysis using dasymetric cartography (United States)

    Garcia, Ricardo A. C.; Oliveira, Sergio C.; Zezere, Jose L.


    Exposed Population is a major topic that needs to be taken into account in a full landslide risk analysis. Usually, risk analysis is based on an accounting of inhabitants number or inhabitants density, applied over statistical or administrative terrain units, such as NUTS or parishes. However, this kind of approach may skew the obtained results underestimating the importance of population, mainly in territorial units with predominance of rural occupation. Furthermore, the landslide susceptibility scores calculated for each terrain unit are frequently more detailed and accurate than the location of the exposed population inside each territorial unit based on Census data. These drawbacks are not the ideal setting when landslide risk analysis is performed for urban management and emergency planning. Dasymetric cartography, which uses a parameter or set of parameters to restrict the spatial distribution of a particular phenomenon, is a methodology that may help to enhance the resolution of Census data and therefore to give a more realistic representation of the population distribution. Therefore, this work aims to map and to compare the population distribution based on a traditional approach (population per administrative terrain units) and based on dasymetric cartography (population by building). The study is developed in the Region North of Lisbon using 2011 population data and following three main steps: i) the landslide susceptibility assessment based on statistical models independently validated; ii) the evaluation of population distribution (absolute and density) for different administrative territorial units (Parishes and BGRI - the basic statistical unit in the Portuguese Census); and iii) the dasymetric population's cartography based on building areal weighting. Preliminary results show that in sparsely populated administrative units, population density differs more than two times depending on the application of the traditional approach or the dasymetric

  9. Dynamic growth of slip surfaces in catastrophic landslides. (United States)

    Germanovich, Leonid N; Kim, Sihyun; Puzrin, Alexander M


    This work considers a landslide caused by the shear band that emerges along the potential slip (rupture) surface. The material above the band slides downwards, causing the band to grow along the slope. This growth may first be stable (progressive), but eventually becomes dynamic (catastrophic). The landslide body acquires a finite velocity before it separates from the substrata. The corresponding initial-boundary value problem for a dynamic shear band is formulated within the framework of Palmer & Rice's ( Proc. R. Soc. Lond. A 332 , 527-548. (doi:10.1098/rspa.1973.0040)) approach, which is generalized to the dynamic case. We obtain the exact, closed-form solution for the band velocity and slip rate. This solution assesses when the slope fails owing to a limiting condition near the propagating tip of the shear band. Our results are applicable to both submarine and subaerial landslides of this type. It appears that neglecting dynamic (inertia) effects can lead to a significant underestimation of the slide size, and that the volumes of catastrophic slides can exceed the volumes of progressive slides by nearly a factor of 2. As examples, we consider the Gaviota and Humboldt slides offshore of California, and discuss landslides in normally consolidated sediments and sensitive clays. In particular, it is conceivable that Humboldt slide is unfinished and may still displace a large volume of sediments, which could generate a considerable tsunami. We show that in the case of submarine slides, the effect of water resistance on the shear band dynamics may frequently be limited during the slope failure stage. For a varying slope angle, we formulate a condition of slide cessation.

  10. Integrating spatial, temporal, and size probabilities for the annual landslide hazard maps in the Shihmen watershed, Taiwan

    Directory of Open Access Journals (Sweden)

    C. Y. Wu


    Full Text Available Landslide spatial, temporal, and size probabilities were used to perform a landslide hazard assessment in this study. Eleven intrinsic geomorphological, and two extrinsic rainfall factors were evaluated as landslide susceptibility related factors as they related to the success rate curves, landslide ratio plots, frequency distributions of landslide and non-landslide groups, as well as probability–probability plots. Data on landslides caused by Typhoon Aere in the Shihmen watershed were selected to train the susceptibility model. The landslide area probability, based on the power law relationship between the landslide area and a noncumulative number, was analyzed using the Pearson type 5 probability density function. The exceedance probabilities of rainfall with various recurrence intervals, including 2, 5, 10, 20, 50, 100 and 200 yr, were used to determine the temporal probabilities of the events. The study was conducted in the Shihmen watershed, which has an area of 760 km2 and is one of the main water sources for northern Taiwan. The validation result of Typhoon Krosa demonstrated that this landslide hazard model could be used to predict the landslide probabilities. The results suggested that integration of spatial, area, and exceedance probabilities to estimate the annual probability of each slope unit is feasible. The advantage of this annual landslide probability model lies in its ability to estimate the annual landslide risk, instead of a scenario-based risk.

  11. Long runout landslides: a solution from granular mechanics

    Directory of Open Access Journals (Sweden)

    Stanislav eParez


    Full Text Available Large landslides exhibit surprisingly long runout distances compared to a rigid body sliding from the same slope, and the mechanism of this phenomena has been studied for decades. This paper shows that the observed long runouts can be explained quite simply via a granular pile flowing downhill, while collapsing and spreading, without the need for frictional weakening that has traditionally been suggested to cause long runouts. Kinematics of the granular flow is divided into center of mass motion and spreading due to flattening of the flowing mass. We solve the center of mass motion analytically based on a frictional law valid for granular flow, and find that center of mass runout is similar to that of a rigid body. Based on the shape of deposits observed in experiments with collapsing granular columns and numerical simulations of landslides, we derive a spreading length Rf~V^1/3. Spreading of a granular pile, leading to a deposit angle much lower than the angle of repose or the dynamic friction angle, is shown to be an important, often dominating, contribution to the total runout distance, accounting for the long runouts observed for natural landslides.

  12. BAPA Database: Linking landslide occurrence with rainfall in Asturias (Spain) (United States)

    Valenzuela, Pablo; José Domínguez-Cuesta, María; Jiménez-Sánchez, Montserrat


    Asturias is a region in northern Spain with a temperate and humid climate. In this region, slope instability processes are very common and often cause economic losses and, sometimes, human victims. To prevent the geological risk involved, it is of great interest to predict landslide spatial and temporal occurrence. Some previous investigations have shown the importance of rainfall as a trigger factor. Despite the high incidence of these phenomena in Asturias, there are no databases of recent and actual landslides. The BAPA Project (Base de Datos de Argayos del Principado de Asturias - Principality of Asturias Landslide Database) aims to create an inventory of slope instabilities which have occurred between 1980 and 2015. The final goal is to study in detail the relationship between rainfall and slope instabilities in Asturias, establishing precipitation thresholds and soil moisture conditions necessary to instability triggering. This work presents the database progress showing its structure divided into various fields that essentially contain information related to spatial, temporal, geomorphological and damage data.

  13. US-China Collaboration on Landslide Research and Student Training (United States)

    Wang, G.


    Funded by a NSF International Research Experience for Students (IRES) project (OIA: 1460034) at the University of Houston (, the author brought eight U.S. students to China in the summer of 2016. The host university at the China side is the China University of Geoscience at Wuhan. The international collaborative project is designed to expose U.S. students to the international landslide research community at an early stage of their careers. The NSF IRES program will support minimum 18 U.S. students (two graduates and four undergraduates per year) to conduct advanced landslide research in the Three Gorges area in China during the summers (eight weeks) of 2016, 2017, and 2018. The 2016 summer program includes a one-week-long pre-training at the University of Houston, a two-week-long intensive Chinese language and cultural course at the main campus of the China University of Geosciences (Wuhan), a four-week-long landslide field investigation in the Three Gorges Reservoir area, and a one-week-long wrap-up at the University of Houston. This presentation will introduce the experiences and lessons that we learned from the first-year activities of the international collaborative project.

  14. A Novel Strategy for landslide displacement and its direction monitoring (United States)

    Zhu, Z.-W.; Yuan, Q.-Y.; Liu, D.-Y.; Liu, B.; Liu, J.-C.; Luo, H.


    Landslide monitoring is important in predicting the behavior of landslides, thereby ensuring environmental, life, and property safety. On the basis of our previous studies, we conducted the double shear test by using a third-generation optical fiber transducer that uses expandable polystyrene (EPS) as base material. However, the third-generation transducer has poor performance when cohesive force is present between the grout and capillary stainless steel pipe of the transducer. Thus, the fourth-generation optical fiber transducer was invented. Similar to the third-generation transducer, the fourth-generation transducer also used EPS as its base material. Single shear test was conducted on the fourth-generation transducer after being grouted with cement mortar (1:1 mix ratio). The micro-bend loss mechanism of the optical fiber was considered, and the optical time domain reflectometry instrument was used. The fact that the loss sequence of optical fibers subjected to loading is different at various locations is found. The relationship of the loading-point displacement VS. optical fiber sliding distance and optical loss were measured. Results show that the maximum initial measurement precision of the newly proposed device is 1mm, the corresponding sliding distance is 21 mm, and the dynamic range is 0-20 mm. The fourth-generation transducer can measure the movement direction of loadings, thus making this transducer applicable for landslide monitoring.

  15. Forecast model of landslides in a short time

    International Nuclear Information System (INIS)

    Sanchez Lopez, Reinaldo


    The IDEAM in development of their functions as member of the national technical committee for the prevention and disasters attention (SNPAD) accomplishes the follow-up, monitoring and forecast in real time of the environmental dynamics that in extreme situations constitute threats and natural risks. One of the frequent dynamics and of greater impact is related to landslides, those that affect persistently the life of the persons, the infrastructure, the socioeconomic activities and the balance of the environment. The landslide in Colombia and in the world are caused mainly by effects of the rain, due to that, IDEAM has come developing forecast model, as an instrument for risk management in a short time. This article presents aspects related to their structure, operation, temporary space resolution, products, results, achievements and projections of the model. Conceptually, the model is support by the principle of the dynamic temporary - space, of the processes that consolidate natural hazards, particularly in areas where the man has come building the risk. Structurally, the model is composed by two sub-models; the general susceptibility of the earthly model and the critical rain model as a denotative factor, that consolidate the hazard process. In real time, the model, works as a GIS, permitting the automatic zoning of the landslides hazard for issue public advisory warming to help makers decisions on the risk that cause frequently these events, in the country

  16. Tunneling through landsliding zone; Jisuberi chitainai no tunnel seko

    Energy Technology Data Exchange (ETDEWEB)

    Konbu, A; Hatabu, K; Kano, T [Tekken Corp., Tokyo (Japan)


    At the new tunnel construction site of the Shirakata tunnel on the Obama line in Yamaguchi Prefecture, a landsliding occurred at about 60 meters to the upper portion obliquely to the right hand side of the shaft when the excavation progressed to about 10 meters from the starting side. The landslide caused displacement at the shaft opening and change in the supports. As a result of the re-investigation, it was confirmed that the slide face went through the tunnel cross section. The measures taken were removal of the upper soil and an adoption of the all ground fastening (AGF) method (injection type long tip fastening method) as an auxiliary construction to stop loosening of the natural ground associated with the tunnel excavation. The result was a completion of tunneling the landsliding zone without a problem. This paper reports the AGF method adopted in the above construction, together with the construction works and natural ground conditions. The AGF method is about the same as the pipe roof method with regard to the natural ground accepting mechanism and the materials used. The difference is building an improved body in a limited area in the natural ground around the steel pipes by injecting the fixing material. The use of this method caused no problems in subsidence and displacement in the surrounding ground, and completed the tunneling construction without an unusual event. 1 ref., 7 figs., 2 tabs.

  17. Modeling and Testing Landslide Hazard Using Decision Tree

    Directory of Open Access Journals (Sweden)

    Mutasem Sh. Alkhasawneh


    Full Text Available This paper proposes a decision tree model for specifying the importance of 21 factors causing the landslides in a wide area of Penang Island, Malaysia. These factors are vegetation cover, distance from the fault line, slope angle, cross curvature, slope aspect, distance from road, geology, diagonal length, longitude curvature, rugosity, plan curvature, elevation, rain perception, soil texture, surface area, distance from drainage, roughness, land cover, general curvature, tangent curvature, and profile curvature. Decision tree models are used for prediction, classification, and factors importance and are usually represented by an easy to interpret tree like structure. Four models were created using Chi-square Automatic Interaction Detector (CHAID, Exhaustive CHAID, Classification and Regression Tree (CRT, and Quick-Unbiased-Efficient Statistical Tree (QUEST. Twenty-one factors were extracted using digital elevation models (DEMs and then used as input variables for the models. A data set of 137570 samples was selected for each variable in the analysis, where 68786 samples represent landslides and 68786 samples represent no landslides. 10-fold cross-validation was employed for testing the models. The highest accuracy was achieved using Exhaustive CHAID (82.0% compared to CHAID (81.9%, CRT (75.6%, and QUEST (74.0% model. Across the four models, five factors were identified as most important factors which are slope angle, distance from drainage, surface area, slope aspect, and cross curvature.

  18. 33 CFR 100.919 - International Bay City River Roar, Bay City, MI. (United States)


    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false International Bay City River Roar, Bay City, MI. 100.919 Section 100.919 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Bay City River Roar, Bay City, MI. (a) Regulated Area. A regulated area is established to include all...

  19. 77 FR 2972 - Thunder Bay Power Company, Thunder Bay Power, LLC, et al. (United States)


    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Thunder Bay Power Company, Thunder Bay Power, LLC, et al.; Notice of Application for Transfer of Licenses, and Soliciting Comments and Motions To Intervene Thunder Bay Power Company Project No. 2404-095 Thunder Bay Power, LLC Midwest Hydro, Inc...

  20. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. (United States)


    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. 162.125 Section 162.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.125 Sturgeon Bay and the Sturgeon Bay Ship...

  1. 77 FR 38488 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY (United States)


    ... 1625-AA00 Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY... restrict vessels from a portion of the St. Lawrence River during the Alexandria Bay Chamber of Commerce... of proposed rulemaking (NPRM) entitled Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence...

  2. Humboldt Bay, California Benthic Habitats 2009 Geodatabase (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  3. Humboldt Bay Benthic Habitats 2009 Aquatic Setting (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  4. San Francisco Bay Water Quality Improvement Fund (United States)

    EPAs grant program to protect and restore San Francisco Bay. The San Francisco Bay Water Quality Improvement Fund (SFBWQIF) has invested in 58 projects along with 70 partners contributing to restore wetlands, water quality, and reduce polluted runoff.,

  5. South Bay Salt Pond Mercury Studies Project (United States)

    Information about the SFBWQP South Bay Salt Pond Mercury Studies Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  6. Humboldt Bay, California Benthic Habitats 2009 Substrate (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  7. Humboldt Bay, California Benthic Habitats 2009 Geoform (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  8. Contaminant transport in Massachusetts Bay (United States)

    Butman, Bradford

    Construction of a new treatment plant and outfall to clean up Boston Harbor is currently one of the world's largest public works projects, costing about $4 billion. There is concern about the long-term impact of contaminants on Massachusetts Bay and adjacent Gulf of Maine because these areas are used extensively for transportation, recreation, fishing, and tourism, as well as waste disposal. Public concern also focuses on Stellwagen Bank, located on the eastern side of Massachusetts Bay, which is an important habitat for endangered whales. Contaminants reach Massachusetts Bay not only from Boston Harbor, but from other coastal communities on the Gulf of Maine, as well as from the atmosphere. Knowledge of the pathways, mechanisms, and rates at which pollutants are transported throughout these coastal environments is needed to address a wide range of management questions.

  9. Bayes linear statistics, theory & methods

    CERN Document Server

    Goldstein, Michael


    Bayesian methods combine information available from data with any prior information available from expert knowledge. The Bayes linear approach follows this path, offering a quantitative structure for expressing beliefs, and systematic methods for adjusting these beliefs, given observational data. The methodology differs from the full Bayesian methodology in that it establishes simpler approaches to belief specification and analysis based around expectation judgements. Bayes Linear Statistics presents an authoritative account of this approach, explaining the foundations, theory, methodology, and practicalities of this important field. The text provides a thorough coverage of Bayes linear analysis, from the development of the basic language to the collection of algebraic results needed for efficient implementation, with detailed practical examples. The book covers:The importance of partial prior specifications for complex problems where it is difficult to supply a meaningful full prior probability specification...

  10. With Prudhoe Bay in decline

    International Nuclear Information System (INIS)

    Davis, J.M.; Pollock, J.R.


    Almost every day, it seems, someone is mentioning Prudhoe Bay---its development activities, the direction of its oil production, and more recently its decline rate. Almost as frequently, someone is mentioning the number of companies abandoning exploration in Alaska. The state faces a double-edged dilemma: decline of its most important oil field and a diminished effort to find a replacement for the lost production. ARCO has seen the Prudhoe Bay decline coming for some time and has been planning for it. We have reduced staff, and ARCO and BP Exploration are finding cost-effective ways to work more closely together through such vehicles as shared services. At the same time, ARCO is continuing its high level of Alaskan exploration. This article will assess the future of Prudhoe Bay from a technical perspective, review ARCO's exploration plans for Alaska, and suggest what the state can do to encourage other companies to invest in this crucial producing region and exploratory frontier

  11. Combined impacts of Black-crowned Night-Heron predation/disturbance and various management activities on Roseate Tern productivity in 2003, and testing of a video surveillance system for recording the diurnal and nocturnal behavior of terns and night-herons at Falkner Island, Stewart B. McKinney National Wildlife Refuge, Connecticut, in 2004: Report to U.S. Fish and Wildlife Service, Stewart B. McKinney National Wildlife Refuge, Westbrook, Connecticut and U.S. Fish and Wildlife Service, Region 5 Regional Office, Hadley, Massachusetts (United States)

    Spendelow, J.A.; Kuter, M.


    Falkner Island (FICT), a unit of the U.S. Fish and Wildlife Service's Stewart B. McKinney National Wildlife Refuge (SBMNWR) since 1985, is located in Long Island Sound 5 km south of Guilford, CT. For more than three decades it has been the site of the only large breeding colony in Connecticut of the federally endangered Northwest Atlantic population of Roseate Terns (Sterna dougallii) and the state's largest colony of Common Terns (S. hirundo). Both species have been studied at this site since 1978 as part of the Falkner Island Tern Project (FITP), and since 1987 also as part of a regional Cooperative Roseate Tern Metapopulation Dynamics and Ecology Project (CRTMP), both coordinated by Dr. Jeffrey A. Spendelow of the U.S. Geological Survey's Patuxent Wildlife Research Center (USGS-PWRC). From 1997-2002 the Roseate Tern breeding population at this site declined by more than 50% from about 150 to about 70 nesting pairs, mostly as a result of the nocturnal predation and disturbance of tern chicks and eggs by Black-crowned Night-Herons (Nycticorax nycticorax). Here we report the results of research done with the goal of improving management of nocturnal predators and developing new practices/structures to reduce losses of tern eggs and chicks so as to prevent the abandonment of this site by Roseate Terns. Notification of release of the USGS 'Quick Response Funds' (QRF) that were to be used to support the part of this study entitled 'Nocturnal behavior/interactions of endangered Roseate Terns and Black-crowned Night-Herons', and final approval of the Study Plan for this research did not occur until after the breeding season in 2003 was well underway. As a result, some work will need to be completed during the 2004 field season. There are two major objectives of this study. The first is to collect basic information (a) on the nocturnal behavior and interactions of Roseate (and Common) Terns with predatory Black-crowned Night-Herons, and (b) on how the behavior of the

  12. Unmanned aerial vehicle (UAV)-based monitoring of a landslide: Gallenzerkogel landslide (Ybbs-Lower Austria) case study. (United States)

    Eker, Remzi; Aydın, Abdurrahim; Hübl, Johannes


    In the present study, UAV-based monitoring of the Gallenzerkogel landslide (Ybbs, Lower Austria) was carried out by three flight missions. High-resolution digital elevation models (DEMs), orthophotos, and density point clouds were generated from UAV-based aerial photos via structure-from-motion (SfM). According to ground control points (GCPs), an average of 4 cm root mean square error (RMSE) was found for all models. In addition, light detection and ranging (LIDAR) data from 2009, representing the prefailure topography, was utilized as a digital terrain model (DTM) and digital surface model (DSM). First, the DEM of difference (DoD) between the first UAV flight data and the LIDAR-DTM was determined and according to the generated DoD deformation map, an elevation difference of between - 6.6 and 2 m was found. Over the landslide area, a total of 4380.1 m 3 of slope material had been eroded, while 297.4 m 3 of the material had accumulated within the most active part of the slope. In addition, 688.3 m 3 of the total eroded material had belonged to the road destroyed by the landslide. Because of the vegetation surrounding the landslide area, the Multiscale Model-to-Model Cloud Comparison (M3C2) algorithm was then applied to compare the first and second UAV flight data. After eliminating both the distance uncertainty values of higher than 15 cm and the nonsignificant changes, the M3C2 distance obtained was between - 2.5 and 2.5 m. Moreover, the high-resolution orthophoto generated by the third flight allowed visual monitoring of the ongoing control/stabilization work in the area.

  13. Tracking and evolution of irrigation triggered active landslides by multi-source high resolution DEM: The Jiaojiacun landslide group of Heifangtai (Northwest of China) (United States)

    Zeng, Runqiang; Meng, Xingmin; Wang, Siyuan; Chen, Guan; Lee, Yajun; Zhang, Yi


    The construction of three large hydropower stations, i.e. Liujia, Yanguo and Bapan, resulted in the immigration of the impacted people to Heifangtai from 1960s. To support the living and farming of the immigrated people, a large amount of water has been pumped from the Yellow River to Heifangtai, which has changed the former underground water budget and led to 111 landslides from 1968 in this area. To reveal the deformation process of landslides in Heifangtai, a quantitative deformation analysis model of landslide based on multi-source DEM data is established using four periods of topographic maps obtained in 1970, 2001, 2010 and 2013 respectively, including two 1:10000 topographic maps and two 1:1000 data acquired from 3D Laser Scanner. The whole study area was divided into two sections based on the two distinct kinds of landslide patterns. The selected morphometric parameters, residual topographic surface and surface roughness, extracted from three typical landslides, and the statistical analysis (Box-plot diagrams) of the temporal variations of these parameters, allowed the reconstruction and tracking of these landslides. We monitored the changing of landslide boundaries, average vertical and horizontal displacement rates and zones of uplift and subsidence. The volumes of removed and/or accumulated material were estimated as well. We can then demonstrate the kinematics of landslides based on information from high-resolution DEM, and the changing table of underground water, ring-shear test and soil-water characteristic curve referenced from other researchers. The results provide a new insight on the use of multi-source high resolution DEM in the monitoring of irrigation-triggered landslides.

  14. Distribution and behavior of major and trace elements in Tokyo Bay, Mutsu Bay and Funka Bay marine sediments

    International Nuclear Information System (INIS)

    Honda, Teruyuki; Kimura, Ken-ichiro


    Fourteen major and trace elements in marine sediment core samples collected from the coasts along eastern Japan, i.e. Tokyo Bay (II) (the recess), Tokyo Bay (IV) (the mouth), Mutsu Bay and Funka Bay and the Northwest Pacific basin as a comparative subject were determined by the instrumental neutron activation analysis (INAA). The sedimentation rates and sedimentary ages were calculated for the coastal sediment cores by the 210 Pb method. The results obtained in this study are summarized as follows: (1) Lanthanoid abundance patterns suggested that the major origin of the sediments was terrigenous material. La*/Lu* and Ce*/La* ratios revealed that the sediments from Tokyo Bay (II) and Mutsu Bay more directly reflected the contribution from river than those of other regions. In addition, the Th/Sc ratio indicated that the coastal sediments mainly originated in the materials from the volcanic island-arcs, Japanese islands, whereas those from the Northwest Pacific mainly from the continent. (2) The correlation between the Ce/U and Th/U ratios with high correlation coefficients of 0.920 to 0.991 indicated that all the sediments from Tokyo Bay (II) and Funka Bay were in reducing conditions while at least the upper sediments from Tokyo Bay (IV) and Mutsu Bay were in oxidizing conditions. (3) It became quite obvious that the sedimentation mechanism and the sedimentation environment at Tokyo Bay (II) was different from those at Tokyo Bay (IV), since the sedimentation rate at Tokyo Bay (II) was approximately twice as large as that at Tokyo Bay (IV). The sedimentary age of the 5th layer (8∼10 cm in depth) from Funka Bay was calculated at approximately 1940∼50, which agreed with the time, 1943∼45 when Showa-shinzan was formed by the eruption of the Usu volcano. (author)

  15. Mobile Bay turbidity plume study (United States)

    Crozier, G. F.


    Laboratory and field transmissometer studies on the effect of suspended particulate material upon the appearance of water are reported. Quantitative correlations were developed between remotely sensed image density, optical sea truth data, and actual sediment load. Evaluation of satellite image sea truth data for an offshore plume projects contours of transmissivity for two different tidal phases. Data clearly demonstrate the speed of change and movement of the optical plume for water patterns associated with the mouth of Mobile bay in which relatively clear Gulf of Mexico water enters the bay on the eastern side. Data show that wind stress in excess of 15 knots has a marked impact in producing suspended sediment loads.

  16. Automation in tube finishing bay

    International Nuclear Information System (INIS)

    Bhatnagar, Prateek; Satyadev, B.; Raghuraman, S.; Syama Sundara Rao, B.


    Automation concept in tube finishing bay, introduced after the final pass annealing of PHWR tubes resulted in integration of number of sub-systems in synchronisation with each other to produce final cut fuel tubes of specified length, tube finish etc. The tube finishing bay which was physically segregated into four distinct areas: 1. tube spreader and stacking area, 2. I.D. sand blasting area, 3. end conditioning, wad blowing, end capping and O.D. wet grinding area, 4. tube inspection, tube cutting and stacking area has been studied

  17. Landslide risk analysis: a multi-disciplinary methodological approach

    Directory of Open Access Journals (Sweden)

    S. Sterlacchini


    Full Text Available This study describes an analysis carried out within the European community project "ALARM" (Assessment of Landslide Risk and Mitigation in Mountain Areas, 2004 on landslide risk assessment in the municipality of Corvara in Badia, Italy. This mountainous area, located in the central Dolomites (Italian Alps, poses a significant landslide hazard to several man-made and natural objects. Three parameters for determining risk were analysed as an aid to preparedness and mitigation planning: event occurrence probability, elements at risk, and the vulnerability of these elements. Initially, a landslide hazard scenario was defined; this step was followed by the identification of the potential vulnerable elements, by the estimation of the expected physical effects, due to the occurrence of a damaging phenomenon, and by the analysis of social and economic features of the area. Finally, a potential risk scenario was defined, where the relationships between the event, its physical effects, and its economic consequences were investigated. People and public administrators with training and experience in local landsliding and slope processes were involved in each step of the analysis.

    A "c