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Sample records for 3-dimensional numerical landslide

  1. Two numerical models for landslide dynamic analysis

    NASA Astrophysics Data System (ADS)

    Hungr, Oldrich; McDougall, Scott

    2009-05-01

    Two microcomputer-based numerical models (Dynamic ANalysis (DAN) and three-dimensional model DAN (DAN3D)) have been developed and extensively used for analysis of landslide runout, specifically for the purposes of practical landslide hazard and risk assessment. The theoretical basis of both models is a system of depth-averaged governing equations derived from the principles of continuum mechanics. Original features developed specifically during this work include: an open rheological kernel; explicit use of tangential strain to determine the tangential stress state within the flowing sheet, which is both more realistic and beneficial to the stability of the model; orientation of principal tangential stresses parallel with the direction of motion; inclusion of the centripetal forces corresponding to the true curvature of the path in the motion direction and; the use of very simple and highly efficient free surface interpolation methods. Both models yield similar results when applied to the same sets of input data. Both algorithms are designed to work within the semi-empirical framework of the "equivalent fluid" approach. This approach requires selection of material rheology and calibration of input parameters through back-analysis of real events. Although approximate, it facilitates simple and efficient operation while accounting for the most important characteristics of extremely rapid landslides. The two models have been verified against several controlled laboratory experiments with known physical basis. A large number of back-analyses of real landslides of various types have also been carried out. One example is presented. Calibration patterns are emerging, which give a promise of predictive capability.

  2. Numerical modelling of propagation of landslides using SPH

    NASA Astrophysics Data System (ADS)

    Montull, Carlos; Pastor, Manuel; Springman, Sarah

    2015-04-01

    Landslides cause severe economic damage and a large number of casualties every year around the world. Engineers and geologists need to understand and predict their properties, such as velocity, depth and run out distance. In addition to experience gained on similar cases, predictions require the application of mathematical, constitutive/rheological and numerical models. Different models are currently used to simulate long run-out landslides in order to elaborate hazard maps. Among the available alternatives, depth integrated models present a reasonable compromise between computational cost and accuracy. The purpose of this paper is to apply the SPH depth integrated model, together with suitable rheological laws, to analize fast landslides. We will present the results obtained with the code Geoflow_SPH to three selected cases: (i) The Frank avalanche, (ii) the Cougar Hill flowslide and (iii) the Sham Tseng debris flow. The results of the simulations include estimations of fundamental aspects of the problem, such as the path followed by the sliding mass, the shape of the run-out area, the maximum run-out, the depth of the final deposit, the pore pressure evolution and the speed evolution of the landslide.

  3. Numerical Modeling of the 2014 Oso, Washington, Landslide.

    NASA Astrophysics Data System (ADS)

    George, D. L.; Iverson, R. M.

    2014-12-01

    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

  4. The program FANS-3D (finite analytic numerical simulation 3-dimensional) and its applications

    NASA Technical Reports Server (NTRS)

    Bravo, Ramiro H.; Chen, Ching-Jen

    1992-01-01

    In this study, the program named FANS-3D (Finite Analytic Numerical Simulation-3 Dimensional) is presented. FANS-3D was designed to solve problems of incompressible fluid flow and combined modes of heat transfer. It solves problems with conduction and convection modes of heat transfer in laminar flow, with provisions for radiation and turbulent flows. It can solve singular or conjugate modes of heat transfer. It also solves problems in natural convection, using the Boussinesq approximation. FANS-3D was designed to solve heat transfer problems inside one, two and three dimensional geometries that can be represented by orthogonal planes in a Cartesian coordinate system. It can solve internal and external flows using appropriate boundary conditions such as symmetric, periodic and user specified.

  5. 3-DIMENSIONAL Numerical Modeling on the Combustion and Emission Characteristics of Biodiesel in Diesel Engines

    NASA Astrophysics Data System (ADS)

    Yang, Wenming; An, Hui; Amin, Maghbouli; Li, Jing

    2014-11-01

    A 3-dimensional computational fluid dynamics modeling is conducted on a direct injection diesel engine fueled by biodiesel using multi-dimensional software KIVA4 coupled with CHEMKIN. To accurately predict the oxidation of saturated and unsaturated agents of the biodiesel fuel, a multicomponent advanced combustion model consisting of 69 species and 204 reactions combined with detailed oxidation pathways of methyl decenoate (C11H22O2), methyl-9-decenoate (C11H20O2) and n-heptane (C7H16) is employed in this work. In order to better represent the real fuel properties, the detailed chemical and thermo-physical properties of biodiesel such as vapor pressure, latent heat of vaporization, liquid viscosity and surface tension were calculated and compiled into the KIVA4 fuel library. The nitrogen monoxide (NO) and carbon monoxide (CO) formation mechanisms were also embedded. After validating the numerical simulation model by comparing the in-cylinder pressure and heat release rate curves with experimental results, further studies have been carried out to investigate the effect of combustion chamber design on flow field, subsequently on the combustion process and performance of diesel engine fueled by biodiesel. Research has also been done to investigate the impact of fuel injector location on the performance and emissions formation of diesel engine.

  6. Numerical modelling of the 1979 Nice landslide-generated tsunami

    NASA Astrophysics Data System (ADS)

    Donnadieu, Claire; Hebert, Hélène; Silva Jacinto, Ricardo; Meyniel, Pauline

    2010-05-01

    On the 16th October 1979, a part of the building site of the Nice airport extension intended to become the new Nice harbour collapsed into the Mediterranean Sea during landfilling operations. This submarine slide of initial volume of 10 millions of m3, located near the seashore, generated a turbidity current that propagated along the Var canyon. A few minutes after the landslide, a small tsunami was observed by several witnesses 60 km along the coast, called "Baie des Anges". The most destructive effect occurred near the city of Antibes, 10 km away from the source, which was inundated and where one person died. In the framework of the RATCOM (Réseau d'Alertes aux Tsunamis et COtiers en Méditerranée) project, this event is numerically simulated with the goal of establishing the appropriate monitoring network which could have detected this event by means of gauges located offshore. Two additional scenarios of hypothetical sources recently identified by IFREMER in the same area are also computed : a small volume of 0.6 millions of m3, close to the 1979 breakdown area, and a larger one of 7 millions of m3, located easterly. A very accurate bathymetric map of the area provided by IFREMER and completed by SHOM data near the coast is used. The dynamics of the slide and the water waves generated are both computed in the shallow water approximation, considering the interaction between the mass of sediments constituting the slide and the water. The landslide is modelled as a Newtonian homogeneous viscous flow sliding under gravity along the bathymetry and the tsunami model is initialized by taking into account the bottom deformation induced by the slide. Incorporation of water in the mass of sediments at the interface between landslide and water can be considered. The equations are solved by a finite difference method based on shock capturing. Numerical results of tsunami waves amplitudes generated by the landslide during the propagation and along the coast are compared

  7. Landslide!

    ERIC Educational Resources Information Center

    Hall-Wallace, Michelle; Mitchell, Carl

    1996-01-01

    Presents a unit that focuses on landslides and integrates earth science, physics, chemistry, and math. Includes activities to investigate porosity, permeability, cohesion, saturation, and gravity. (JRH)

  8. Water uptake by a maize root system - An explicit numerical 3-dimensional simulation.

    NASA Astrophysics Data System (ADS)

    Leitner, Daniel; Schnepf, Andrea; Klepsch, Sabine; Roose, Tiina

    2010-05-01

    Water is one of the most important resources for plant growth and function. An accurate modelling of the unsaturated flow is not only substantial to predict water uptake but also important to describe nutrient movement regarding water saturation and transport. In this work we present a model for water uptake. The model includes the simultaneous flow of water inside the soil and inside the root network. Water saturation in the soil volume is described by the Richards equation. Water flow inside the roots' xylem is calculated using the Poiseuille law for water flow in a cylindrical tube. The water saturation in the soil as well as water uptake of the root system is calculated numerically in three dimensions. We study water uptake of a maize plant in a confined pot under different supply scenarios. The main improvement of our approach is that the root surfaces act as spatial boundaries of the soil volume. Therefore water influx into the root is described by a surface flux instead of a volume flux, which is commonly given by an effective sink term. For the numerical computation we use the following software: The 3-dimensional maize root architecture is created by a root growth model based on L-Systems (Leitner et al 2009). A mesh of the surrounding soil volume is created using the meshing software DistMesh (Persson & Strang 2004). Using this mesh the partial differential equations are solved with the finite element method using Comsol Multiphysics 3.5a. Modelling results are related to accepted water uptake models from literature (Clausnitzer & Hopmans 1994, Roose & Fowler 2004, Javaux et al 2007). This new approach has several advantages. By considering the individual roots it is possible to analyse the influence of overlapping depletion zones due to inter root competition. Furthermore, such simulations can be used to estimate the influence of simplifying assumptions that are made in the development of effective models. The model can be easily combined with a nutrient

  9. Numerical modeling on tertiary creep behavior of extreme rainfall-induced landslides with TRMM application for landslide early warning

    NASA Astrophysics Data System (ADS)

    Dok, A.; Fukuoka, H.; Katsumi, T.; Inui, T.

    2012-12-01

    In help issue warning of extreme rainfall-induced landslide in tropical soils of Southeast Asian countries, it requires the study of landslide mechanism induced by generated excess pore water pressure at the sliding surface due to groundwater table rise under rainfall storm, and examination of empirical relationship between rainfall characteristics and past landslide occurrence (precipitation analysis). To investigate the tertiary creep behavior in soils found by Fukuzono, 1985 (d2x/dt2=A(dx/dt)α, where x is surface displacement, t is time, and A and α are constant), a series of pore-pressure-controlled tests on saturated sands were undertaken in the ring shear apparatus. The tests were conducted under combined condition of predefined normal stress and shear stress with pore water pressure changes to simulate the potential sliding surface condition in heavy rainfall. Sand, its mixture with clay material, and soil samples taken at actual landslide sliding surface were used for specimen. Repeated shear test for a specimen was also additionally conducted to produce reactivated motion landslides. Numerical model simulating the Tertiary creep behavior (or progressive failure) is constructed to develop a most appropriate method for landslide early warning combined with TRMM satellite rainfall data. TRMM data were selected to apply to the Japanese Soil Water Index (SWI) in distributing threshold of highly nonlinear rainfall patterns for estimating the landslide occurrence in developing regions: Southeast Asian countries, where very limited number of rain gauges is available, and there is no implemented methodology for issuing effective warming of landslides yet. It is through the plot of total water of 3 serial tank models and daily precipitation with case example of landslide disasters took place in Beichuan city, (located on the 2008 Chinese Wenchuan earthquake fault) and Hofu city, Japan which were hit by heavy rainfall attacked in 2009. Consequently, it is

  10. Landslide!

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-486, 17 September 2003

    This August 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows part of a deposit created by a landslide off the wall of a crater near 12.3oN, 21.3oW. The crater wall is not shown; it is several kilometers to the left of this picture. The debris that slid from the crater wall came from the left/upper left (northwest) and moved toward the lower right (southeast). The crater floor onto which the debris was deposited has more small meteor craters on it than does the landslide material; this indicates that there was a considerable interval between the time when the crater floor formed, and when the landslide occurred. This picture covers an area 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  11. Tsunamis generated by 3D deformable landslides in various scenarios: laboratory experiments and numerical modeling

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Landslide generated tsunamis such as Lituya Bay, Alaska 1958 account for some of highest recorded tsunami runup heights. 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 pneumatic pistons down slope. Two different landslide materials are used 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 with video image processing. The measured landslide and wave parameters are compared between the planar hill slope used in various scenarios and the convex hill slope of the conical island. The energy conversion rates from the landslide motion to the wave train is quantified for the planar and convex hill slopes. The wave runup data on the opposing headland is analyzed and evaluated with wave theories. The measured landslide and tsunami data serve to validate and advance three-dimensional numerical landslide tsunami prediction models. Two 3D Navier-Stokes models were tested, the commercial code FLOW-3D

  12. Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03582 Landslide

    This landslide occurred in Coprates Chasma.

    Image information: VIS instrument. Latitude 12.6S, Longitude 296.9E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Landslide

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02160 Landslide

    This large landslide is located within Ganges Chasma.

    Image information: VIS instrument. Latitude -7.6N, Longitude 315.8E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. Landslide Kinematical Analysis through Inverse Numerical Modelling and Differential SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Castaldo, R.; Tizzani, P.; Lollino, P.; Calò, F.; Ardizzone, F.; Lanari, R.; Guzzetti, F.; Manunta, M.

    2015-11-01

    The aim of this paper is to propose a methodology to perform inverse numerical modelling of slow landslides that combines the potentialities of both numerical approaches and well-known remote-sensing satellite techniques. In particular, through an optimization procedure based on a genetic algorithm, we minimize, with respect to a proper penalty function, the difference between the modelled displacement field and differential synthetic aperture radar interferometry (DInSAR) deformation time series. The proposed methodology allows us to automatically search for the physical parameters that characterize the landslide behaviour. To validate the presented approach, we focus our analysis on the slow Ivancich landslide (Assisi, central Italy). The kinematical evolution of the unstable slope is investigated via long-term DInSAR analysis, by exploiting about 20 years of ERS-1/2 and ENVISAT satellite acquisitions. The landslide is driven by the presence of a shear band, whose behaviour is simulated through a two-dimensional time-dependent finite element model, in two different physical scenarios, i.e. Newtonian viscous flow and a deviatoric creep model. Comparison between the model results and DInSAR measurements reveals that the deviatoric creep model is more suitable to describe the kinematical evolution of the landslide. This finding is also confirmed by comparing the model results with the available independent inclinometer measurements. Our analysis emphasizes that integration of different data, within inverse numerical models, allows deep investigation of the kinematical behaviour of slow active landslides and discrimination of the driving forces that govern their deformation processes.

  15. A GIS-based numerical simulation of the March 2014 Oso landslide fluidized motion

    NASA Astrophysics Data System (ADS)

    Fukuoka, H.; Ogbonnaya, I.; Wang, C.

    2014-12-01

    Sliding and flowing are the major movement type after slope failures. Landslides occur when slope-froming material moves downhill after failing along a sliding surface. Most debris flows originally occur in the form of rainfall-induced landslides before they move into valley channel. Landslides that mobilize into debris flows usually are characterized by high-speed movement and long run-out distance and may present the greatest risk to human life. The 22 March 2014 Oso landslide is a typical case of landside transformint to debris flow. The landslide was triggered on the edge of a plateau about 200 m high composed of glacial sediments after excessive prolonged rainfall of 348 in March 2014. After its initiation, portions of the landslide materials transitioned into a rapidly moving debris flow which traveled long distances across the downslope floodplain. U.S. Geological Survey estimated the volume of the slide to be about 7 million m3, and it traveled about 1 km from the toe of the slope. The apparent friction angle measured by the energy line drawn from the crown of the head scarp to the toe of the deposits which reached largest distance, was only 5~6 degrees. we performed two numerical modeling to predicting the runout distance and to get insight into the behaviour of the landslide movement. One is GIS-based revised Hovland's 3D limit equilibrium model which is used to simulate the movement and stoppage of a landslide. In this research, sliding is defined by a slip surface which cuts through the slope, causing the mass of earth to move above it. The factor of safety will be calculated step by step during the sliding process simulation. Stoppage is defined by the factor of safety much greater than one and the velocity equal zero. The other is GIS-based depth-averaged 2D numerical model using a coupled viscous and Coulomb type law to simulate a debris flow from initiation to deposition. We compared our simulaiton results with the results of preliminary computer

  16. Landslides

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    The slumping of materials in the walls of this impact crater illustrate the continued erosion of the martian surface. Small fans of debris as well as larger landslides are observed throughout the THEMIS image.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 40.9, Longitude 120.5 East (239.5 West). 19 meter/pixel resolution.

  17. Landslide/reservoir interaction: 3D numerical modelling of the Vajont rockslide and generated water wave

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    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

  18. Kinematic evolution of the Ivancich landslide: analysis, characterization and numerical modelling

    NASA Astrophysics Data System (ADS)

    Lollino, P.; Angeli, M. G.; Ardizzone, F.; Calò, F.; Cardinali, M.; Castaldo, R.; Fiorucci, F.; Guzzetti, F.; Manconi, A.; Manunta, M.; Manzo, M.; Paglia, L.; Pontoni, F.; Reichenbach, P.; Rossi, M.; Tizzani, P.

    2012-04-01

    The Ivancich landslide is an ancient phenomenon composed of a stratified detritum mass with fragments of limestone blocks sliding on a substratum of in-place marly-sandstone. The landslide affects a densely inhabited marginal area of the famous historical town of Assisi (Central Italy), producing severe damages to private and public buildings hereby located. The landslide body is overlain by the karstic massif of Mt. Subasio, which represents a large high-permeability reservoir that supplies most part of groundwater to the underlying slope. The sliding surface lies within the most weathered portion of the marly-sandstone substratum, close to the contact with the overlying detritum mass, and its depth increases from 20 to 60 m below g.l. from the landslide toe to the top. The whole length of the landslide body is about 1500 m. A large field monitoring dataset of the landslide process is available, composed of piezometric and in-depth inclinometric measurements acquired for about a decade all over the landslide body. Furthermore surface displacement time-series have been retrieved via an advanced space-based Differential SAR interferometry analysis (SBAS-DInSAR, being discussed in a contribution presented by the Authors in a parallel session). In this work, we aim at developing numerical models for the interpretation of the mechanism of Ivancich landslide reactivation as well as of the related controlling factors. To this end, we are currently processing the available geomorphological information, field monitoring data, in-situ and laboratory investigations. As first analysis, we will investigate the flow process occurring within the slope through both steady-state and transient seepage finite element analyses, and compare the results with the available field piezometric measurements. Then, drained and coupled stress-strain finite element analyses will be performed to investigate the kinematic evolution of the landslide, and define the corresponding displacement

  19. Numerical modeling of landslide generated tsunamis in the bay of Biscay

    NASA Astrophysics Data System (ADS)

    Frere, Antoine; Hebert, Helene

    2016-04-01

    Tsunami hazard in metropolitan France is poorly known. The TANDEM (Tsunamis in northern AtlaNtic : Definition of Effects by Modeling) project is a French initiative to draw lessons from the 2011 catastrophic tsunami in Japan on French coastlines, in order to provide guidance for risk assessment on the nuclear facilities in the area. This project is aimed at adapting numerical methods of tsunami hazard assessment against the outstanding observation database of the 2011 tsunami, in order to apply these validated methods to the definition of the tsunami hazard for the French Atlantic and Channel coastlines. Landslide induced tsunami hazard in the Bay of Biscay France (NE Atlantic ocean) is poorly known. Investigation on the continental slope of the Bay show the existence of numerous landslide scars, but no real risk assessment studies were made to determine the potential tsunami hazard from those landslide. This work focuses on tsunami induced by landslides, and aims to assess the threat using numerical simulation. We assumes that the landslide has a fluid-like behaviour and applies shallow water/thin layer approximations to both aspect. The similarity of the resulting equations of momentum and mass conservation enables to use a single Godunov-like numerical scheme for both parts of the model. The model results are then carried into a multigrid dispersive model in order to get better estimation of the water height near the coast. This second model uses the Boussinesq equations for larger scale grids and the Saint-Venant equations near the coast, and is resolved using a Crank-Nicholson scheme. The first study zone is located in the Cap Breton canyon region in the south of the Bay. Investigation is carried out to identify scenarios that could have caused paleo-tsunamis, with a special interest on a large scar off the canyon(~70 km3). 4 scenarios of varying volumes (from 17 to 70 km3) and depth are carried into the model and the result show maximum water heights of up to

  20. Numerical modelling of potential submarine landslides and generated tsunami in Sumatra

    NASA Astrophysics Data System (ADS)

    Fernandez-Nieto, E.; Mangeney, A.; Singh, S. C.; Chauhan, A.; Bouchut, F.; Castro Díaz, M.

    2010-12-01

    Recent studies suggests that tsunami risk along the SW coast of Sumatra could be due to co-seismic slip along a backthrust at the NE Margin of the Mentawai Island and associated landslides (Singh et al., 2010). Using a combination of high-resolution seismic reflection and bathymetry data, they observed deposits of large submarine landslides at the NE margin of Mentawai Island and suggest that the high wave that occurred in 1797 might have been enhanced by landslides, producing a large localised tsunami. Until now most of the work devoted to tsunami hazard assessment in the area of Sumatra Island focussed on megaearthquakes earthquakes generated tsunamis. Therefore, estimating the run up heights due to submarine landslides is essential for risk mitigation along the SW coast of Sumatra. A series of numerical scenarios are performed here to simulate potential submarine landslides and generated tsunamis in the area of Sumatra Island. The height and velocity of the water wave and the impact zones are calculated using a new numerical model solving the depth-averaged shallow water equations with high order finite volume methods. This model corresponds to the 2D extension of the model developed by Fernández-Nieto et al., 2008. The fluidized mass is modeled using a generalization of the Savage-Hutter model [Savage and Hutter, 1989] by including the role of buoyancy and fluid into the thin-layer equations with a Coulomb-type friction law. Our model takes into account the coupling between the fluid and the landslides and incorporates the rigorous description of topography effects that play a key role in the dynamics of landslides. We study the magnitude of variation of the wave expected depending on the location and volume released. These results shows that landslide generated tsunamis have to be taken into account for risk assessment in the area of Sumatra Island. E.D. Fernández-Nieto, F. Bouchut, D. Bresch, M.J. Castro, A. Mangeney, 2008. A new Savage-Hutter type model

  1. Numerical modeling of landslide-generated tsunami using adaptive unstructured meshes

    NASA Astrophysics Data System (ADS)

    Wilson, Cian; Collins, Gareth; Desousa Costa, Patrick; Piggott, Matthew

    2010-05-01

    Landslides impacting into or occurring under water generate waves, which can have devastating environmental consequences. Depending on the characteristics of the landslide the waves can have significant amplitude and potentially propagate over large distances. Linear models of classical earthquake-generated tsunamis cannot reproduce the highly nonlinear generation mechanisms required to accurately predict the consequences of landslide-generated tsunamis. Also, laboratory-scale experimental investigation is limited to simple geometries and short time-scales before wave reflections contaminate the data. Computational fluid dynamics models based on the nonlinear Navier-Stokes equations can simulate landslide-tsunami generation at realistic scales. However, traditional chessboard-like structured meshes introduce superfluous resolution and hence the computing power required for such a simulation can be prohibitively high, especially in three dimensions. Unstructured meshes allow the grid spacing to vary rapidly from high resolution in the vicinity of small scale features to much coarser, lower resolution in other areas. Combining this variable resolution with dynamic mesh adaptivity allows such high resolution zones to follow features like the interface between the landslide and the water whilst minimising the computational costs. Unstructured meshes are also better suited to representing complex geometries and bathymetries allowing more realistic domains to be simulated. Modelling multiple materials, like water, air and a landslide, on an unstructured adaptive mesh poses significant numerical challenges. Novel methods of interface preservation must be considered and coupled to a flow model in such a way that ensures conservation of the different materials. Furthermore this conservation property must be maintained during successive stages of mesh optimisation and interpolation. In this paper we validate a new multi-material adaptive unstructured fluid dynamics model

  2. Landslide-generated tsunamis in a perialpine lake: Historical events and numerical models

    NASA Astrophysics Data System (ADS)

    Hilbe, Michael; Anselmetti, Flavio S.

    2014-05-01

    Many of the perialpine lakes in Central Europe - the large, glacier-carved basins formed during the Pleistocene glaciations of the Alps - have proven to be environments prone to subaquatic landsliding. Among these, Lake Lucerne (Switzerland) has a particularly well-established record of subaquatic landslides and related tsunamis. Its sedimentary archive documents numerous landslides over the entire Holocene, which have either been triggered by earthquakes, or which occurred apparently spontaneously, possibly due to rapid sediment accumulation on delta slopes. Due to their controlled boundary conditions and the possibility to be investigated on a complete basinal scale, such lacustrine tsunamis may be used as textbook analogons for their marine counterparts. Two events in the 17th century illustrate these processes and their consequences: In AD 1601, an earthquake (Mw ~ 5.9) led to widespread failure of the sediment drape covering the lateral slopes in several basins. The resulting landslides generated tsunami waves that reached a runup of several metres, as reported in historical accounts. The waves caused widespread damage as well as loss of lives in communities along the shores. In AD 1687, the apparently spontaneous collapse of a river delta in the lake led to similar waves that damaged nearby villages. Based on detailed information on topography, bathymetry and the geometry of the landslide deposits, numerical simulations combining two-dimensional, depth-averaged models for landslide propagation, as well as for tsunami generation, propagation and inundation, are able to reproduce most of the reported tsunami effects for these events. Calculated maximum runup of the waves is 6 to >10 m in the directly affected lake basins, but significantly less in neighbouring basins. Flat alluvial plains adjacent to the most heavily affected areas are inundated over distances of several hundred metres. Taken as scenarios for possible future events, these past events suggest

  3. Mathematical, Constitutive and Numerical Modelling of Catastrophic Landslides and Related Phenomena

    NASA Astrophysics Data System (ADS)

    Pastor, M.; Fernández Merodo, J. A.; Herreros, M. I.; Mira, P.; González, E.; Haddad, B.; Quecedo, M.; Tonni, L.; Drempetic, V.

    2008-02-01

    Mathematical and numerical models are a fundamental tool for predicting the behaviour of geostructures and their interaction with the environment. The term “mathematical model” refers to a mathematical description of the more relevant physical phenomena which take place in the problem being analyzed. It is indeed a wide area including models ranging from the very simple ones for which analytical solutions can be obtained to those more complicated requiring the use of numerical approximations such as the finite element method. During the last decades, mathematical, constitutive and numerical models have been very much improved and today their use is widespread both in industry and in research. One special case is that of fast catastrophic landslides, for which simplified methods are not able to provide accurate solutions in many occasions. Moreover, many finite element codes cannot be applied for propagation of the mobilized mass. The purpose of this work is to present an overview of the different alternative mathematical and numerical models which can be applied to both the initiation and propagation mechanisms of fast catastrophic landslides and other related problems such as waves caused by landslides.

  4. Numerical Simulations of Landslides Calibrated Against Laboratory Experiments for Application to Asteroid Surface Processes

    NASA Astrophysics Data System (ADS)

    Richardson, Derek C.; Blum, J.; Weinhart, T.; Schwartz, S. R.; Michel, P.; Walsh, K. J.

    2012-10-01

    Spacecraft images of asteroids show evidence of low-gravity granular flows. Interpretation of these flows requires numerical modeling, which in turn requires code validation at laboratory scales. We have implemented a soft-sphere discrete element method (SSDEM) for modeling granular flows in our numerical code (Schwartz et al. 2012, Granular Matter 14, 363). Here we present results from a study to calibrate our code against controlled landslide experiments in order to determine the SSDEM parameters that best match real materials, to see how changes in those parameters affect the flow, and to mimic effects such as those due to irregular particle shapes. The apparatus, designed at University of Braunschweig, is a 0.6 × 0.8 m enclosed bed with a surface comprised of 10 mm diameter glass spheres glued into precisely drilled holes in a metal plate. The exact positions and depths of each of these glued spheres are input to the simulations. The experiments consist of filling the apparatus with loose glass beads (also 10 mm diameter) up to a set depth then gradually tilting the bed to note the angle of landslide initiation and the characteristics of the resulting flow. We reproduce this procedure in simulations, which we find are quite sensitive to the adopted SSDEM parameters, e.g., rolling friction and tangential damping delay landslide onset, while higher particle elasticity gives rise to faster, shorter-duration landslides. Preliminary results show a best match to the experiments (landslide initiation around 25 degrees) when adopting low static friction and no rolling friction in the simulations, but more experiments are in process. In future work, we will perform simulations in low-gravity environments representative of asteroid surfaces. This work is supported in part by grant NNX08AM39G from the NASA Office of Space Science. This study resulted from International Team collaboration #202 sponsored by ISSI in Switzerland.

  5. Estimation of dynamic friction of the Akatani landslide from seismic waveform inversion and numerical simulation

    NASA Astrophysics Data System (ADS)

    Yamada, Masumi; Mangeney, Anne; Matsushi, Yuki; Moretti, Laurent

    2016-06-01

    We performed numerical simulations of the 2011 deep-seated Akatani landslide in central Japan to understand the dynamic evolution of friction of the landslide. By comparing the forces obtained from numerical simulation to those resolved from seismic waveform inversion, the coefficient of the friction during sliding was investigated in the range of 0.1 to 0.4. The simulation assuming standard Coulomb friction shows that the forces obtained by the seismic waveform inversion are well explained using a constant friction of μ = 0.3. A small difference between the residuals of Coulomb simulation and a velocity-dependent simulation suggests that the coefficient of friction over the volume is well constrained as 0.3 most of time during sliding. It suggests the sudden loss of shearing resistance at the onset of sliding, i.e., sudden drop of the initial coefficient of friction in our model, which accelerates the deep-seated landslide. Our numerical simulation calibrated by seismic data provides the evolution of dynamic friction with a reasonable resolution in time, which is difficult to obtain from a conventional runout simulation, or seismic waveform inversion alone.

  6. The numerical-statistical approach for hazard prediction of landslides and its application in Ukraine

    NASA Astrophysics Data System (ADS)

    Trofimchuk, O.; Kaliukh, Iu.

    2012-04-01

    More than 90% of the territory of Ukraine has complex ground conditions. Unpredictable changes of natural geological and man-made factors governing ground conditions, may lead to dangerous deformation processes resulting in accidents and disasters. Among them, landslides are the first by the amount of the inflicted damage in Ukraine and the second only to earthquakes in the world. Totally about 23 000 landslides were identified in the territory of Ukraine. The standard deterministic procedure of assessment of the slope stability, especially with the lack of reference engineering geological data, results in obtaining estimated values of stability coefficients differing from the real ones in many cases. Application of a probabilistic approach will allow to take into account the changeable properties of soils and to determine danger and risk of landslide dislocations. The matter of choice of landslide protection measures is directly connected with a risk: expensively but reliably or cheaper but with a great probability of accidents. The risk determines the consequences either economic, social or others, of a potential landslide dislocation on the slope both during construction of a retaining structure on it and in the process of its further maintenance. The quintessence of risk determination consists in the following: study and extrapolation of the past events for each specific occurrence. Expected conclusions and probable damages as a result of a calculated and accepted risk can be determined only with a certain level of uncertainty. Considering this fact improvement of the accuracy of numerical and analytical estimates when calculating the risk magnitude makes it possible to reduce the uncertainty. Calculations of the Chernivtsi shear landslides (Ukraine) were made with an application of Plaxis software and due account of a risk of its displacement was performed for the typical distribution diagram of the landslide-prone slope. The calculations showed that seismic

  7. Numerical modelling comparison of slow landslides: the Portalet case study (Central Pyrenees-Spain)

    NASA Astrophysics Data System (ADS)

    Fernandez-Merodo, Jose Antonio; Garcia-Davalillo, Juan Carlos; Herrera, Gerardo

    2013-04-01

    Slow-moving landslides are a wide-spread type of active mass movement that cause severe damages to infrastructures and may be a precursor of sudden catastrophic slope failures. In this context, modelling slow-moving landslide behaviour is an important task in order to quantify and reduce the risk associated to this geological process. In practice, landslide occurrence and stability conditions are evaluated for a given scenario through a stability factor based on limit equilibrium analysis. This "static" approximation is hardly applied when boundary conditions are time dependent. Apart from earthquake studies, time dependent analysis is required when: (i) hydrological conditions change as in the case of rainfall; (ii) resistant parameters are reduced as in the case of strain softening or weathering processes and (iii) creep behaviour is taken into account. Different numerical models can be applied to reproduce the kinematic behaviour of large slow landslides. This paper compares four different models: i) a direct correlation with measured rainfall, ii) a simple 1D infinite slope viscoplastic model [1], iii) a 2D elasto-plastic finite element model [2] and iv) a 2D visco-plastic finite element model [3]. These models, ordered by increasing level of complexity, are compared by applying them to the Portalet case study. The Portalet landslide (Central Spanish Pyrenees) is an active paleo-landslide that has been "reactivated" by the construction of a parking area at the toe of the slope in 2004. This landslide is still active despite the corrective measures carried out to stabilize it. The measurements obtained with different monitoring techniques (ground based SAR, advanced DInSAR processing of satellite SAR images, DGPS and inclinometers) indicate that the hillside is still moving today following two patterns. The first one corresponds to a slow continuous motion of constant speed of about 100 mm/year, the second one corresponds to accelerations of the moving mass when

  8. Landslides falling onto a shallow erodible substrate or water layer: an experimental and numerical approach

    NASA Astrophysics Data System (ADS)

    Crosta, G. B.; De Blasio, F. V.; Locatelli, M.; Imposimato, S.; Roddeman, D.

    2015-09-01

    Landslides often collapse in areas covered by alluvial deposits forming an erodible layer. This erodible substrate may deform plastically under the intense shear stress of the landslide mass. In other cases, the collapse occurs onto a water basin or tidal flat, creating impulse water waves whilst the landslide may be lubricated by a water layer underneath. In either cases the presence of a medium underneath the landslide will change its dynamics introducing complex processes. While frictional, dry masses and taluses generally hamper the landslide motion. In this work, we present some experiments mimicking the collapse of a landslide onto shallow erodible or water layers. The landslide is simulated with a granular material (sand or gravel) flowing on an incline (35-66°) followed by a horizontal sector covered with a granular bed 1 to 2 cm thick or with a 0.5-1 cm of water. Monitoring evolution in time allows us to describe in detail the process of fluidization of the material at impact, the generation of impact waves, and the erosion process. Concerning impact on a sand layer, the apparent friction coefficient (H/L) is found to increase with the chute slope angle and with the thickness of the erodible layer, and to decrease with the volume. At low slope angles, the material accumulates backwards in a shock wave mode, while at larger slope angles (>45°) it accumulates by prograding forward. A granular avalanche falling from the slope is partially reflected at the sharp slope break where erosion occurs and then propagates initially as a wave partially eroding the superficial material. Folding and thrusting occur within the dense shear flow and the erodible layer. Experiments with a water layer show that the dynamics depends much on the permeability of the granular avalanche. FEM numerical simulations replicate and allow to describe and understand both the spreading and the erosion, and internal deformation recorded in the erodible layer. Experimental findings are

  9. Real time control and numerical simulation of pipeline subjected to landslide

    SciTech Connect

    Cuscuna, S.; Giusti, G.; Gramola, C.

    1984-06-01

    This paper describes SNAM research activity in the study of behaviour and real-time control of pipelines in landslide areas. The subject can be delt considering three different aspects: 1. Geotechnical characterization of unstable soils. The mechanical parameters of soil and the landslide types are defined; 2. Structural analysis of pipe-soil system. By means of a finite element program it's possible to study the pipe-soil interaction; in this numerical code the soil parameters attend by the non-linear elastic behaviour of pipe restraints. The results of this analysis are the location of the expected most stressed sections of pipe and the global behaviour of pipe inside the soil. 3. Instrumental control. The adoption of a suitable appliance of vibrating wire strain gauges allows the strain control of pipe in time. The aim is to make possible timely interventions in order to guarantee the installation safety.

  10. 3D numerical investigation on landslide generated tsunamis around a conical island

    NASA Astrophysics Data System (ADS)

    Montagna, Francesca; Bellotti, Giorgio

    2010-05-01

    This paper presents numerical computations of tsunamis generated by subaerial and submerged landslides falling along the flank of a conical island. The study is inspired by the tsunamis that on 30th December 2002 attacked the coast of the volcanic island of Stromboli (South Tyrrhenian sea, Italy). In particular this paper analyzes the important feature of the lateral spreading of landside generated tsunamis and the associated flooding hazard. The numerical model used in this study is the full three dimensional commercial code FLOW-3D. The model has already been successfully used (Choi et al., 2007; 2008; Chopakatla et al, 2008) to study the interaction of waves and structures. In the simulations carried out in this work a particular feature of the code has been employed: the GMO (General Moving Object) algorithm. It allows to reproduce the interaction between moving objects, as a landslide, and the water. FLOW-3D has been firstly validated using available 3D experiments reproducing tsunamis generated by landslides at the flank of a conical island. The experiments have been carried out in the LIC laboratory of the Polytechnic of Bari, Italy (Di Risio et al., 2009). Numerical and experimental time series of run-up and sea level recorded at gauges located at the flanks of the island and offshore have been successfully compared. This analysis shows that the model can accurately represent the generation, the propagation and the inundation of landslide generated tsunamis and suggests the use of the numerical model as a tool for preparing inundation maps. At the conference we will present the validation of the model and parametric analyses aimed to investigate how wave properties depend on the landslide kinematic and on further parameters such as the landslide volume and shape, as well as the radius of the island. The expected final results of the research are precomputed inundation maps that depend on the characteristics of the landslide and of the island. Finally we

  11. Rainfall triggered landslides in unsaturated soils: a numerical sensitivity analysis for rainfall threshold

    NASA Astrophysics Data System (ADS)

    Ahmadiadli, M.; Huvaj, N.; Toker, K.

    2012-04-01

    Catastrophic precipitation-induced landslides have frequently hit villages, towns and roads in Black Sea Region in northern Turkey, causing extensive damage and many fatalities. Due to global climatic changes, the intensity and frequency of extreme rainfall events are expected to increase. In addition, due to limited available land on level ground, urbanization continue to increase on sloping ground which increases the exposure and elements at risk. Most available methods for predicting rainfall-induced slope instability are based on statistical data of past slope failures and rainfall events. These may often give conservative or unconservative faulty warnings, so a physically-based model that takes into account the mechanism of the problem should be incorporated for more accurate warning system. In this study, main aspects of rainfall triggered landslides, such as infiltration in an unsaturated soil profile, changes in soil suction and shear strength, development of instability in terms of factor of safety and deformations have been studied numerically. The factors/issues that govern this mechanism have been evaluated and a sensitivity analysis is performed using finite element method. We propose a simple 2D numerical approach that is able to predict the evolution of the key factors governing slope stability as a tool to predict the onset of slope failure, with potential benefits for early warning systems. The effect of antecedent rainfall, and different rainfall intensity-duration schemes (short duration intense rainfall, prolonged low intensity rainfall etc.) are considered in evaluating the threshold critical rainfall that may trigger landslides. The approach is calibrated through a well-documented case history, for which the results will be presented in terms of soil suction, deformation and factor of safety versus time and predicted triggering rainfall. The proposed method can be a first-step towards an integrated early warning system for rainfall triggered

  12. Numerical modeling of the seismic response of a large pre-existing landslide in the Marmara region

    NASA Astrophysics Data System (ADS)

    Bourdeau, Céline; Lenti, Luca; Martino, Salvatore

    2015-04-01

    Turkey is one of the geologically most active regions of Europe prone to natural hazards in particular earthquakes and landslides. Detailed seismological studies show that a catastrophic event is now expected in the Marmara region along the North Anatolian Fault Zone (NAFZ). On the shores of the Marmara sea, about 30km East of Istanbul and 15km North from the NAFZ, urbanization is fastly growing despite the presence of pre-existing large landslides. Whether such landslides could be reactivated under seismic shaking is a key question. In the framework of the MARsite European project, we selected one of the most critical landslides namely the Büyükçekmece landslide in order to assess its local seismic response. Based on detailed geophysical and geotechnical field investigations, a high-resolution engineering-geological model of the landslide slope was reconstructed. A numerical modeling was carried out on a longitudinal cross section of this landslide with a 2D finite difference code FLAC in order to assess the local seismic response of the slope and to evaluate the consistency of conditions suitable for the earthquake-induced reactivation of the landslide. The obtained ground-motion amplification pattern along the slope surface is very complex and is strongly influenced by properties changes between the pre-existing landslide mass and the surrounding material. Further comparisons of 2D versus 1D ground-motion amplifications on the one hand and 2D versus topographic site effects on the other hand will shed light on the parameters controlling the spatial variations of ground-motion amplifications along the slope surface.

  13. Definition of a geometric model for landslide numerical modeling from the integration of multi-source geophysical data.

    NASA Astrophysics Data System (ADS)

    Gance, Julien; Bernardie, Séverine; Grandjean, Gilles; Malet, Jean-Philippe

    2014-05-01

    Landslide hazard can be assessed through numerical hydro-mechanical models. These methods require different input data such as a geometric model, rheological constitutive laws and associated hydro-mechanical parameters, and boundary conditions. The objective of this study is to fill the gap existing between geophysical and engineering communities. This gap prevents the engineering community to use the full information available in geophysical imagery. A landslide geometrical model contains information on the geometry and extent of the different geotechnical units of the landslide, and describes the layering and the discontinuities. It is generally drawn from punctual geotechnical tests, using interpolation, or better, from the combined use of a geotechnical test and the iso-value of geophysical tomographies. In this context, we propose to use a multi-source geophysical data fusion strategy as an aid for the construction of landslide geometric models. Based on a fuzzy logic data fusion method, we propose to use different geophysical tomographies and their associated uncertainty and sensitivity tomograms to design a "probable" geometric model. This strategy is tested on a profile of the Super-Sauze landslide using P-wave velocity, P-wave attenuation and electrical resistivity tomography. We construct a probable model and a true model for numerical modeling. Using basic elastic constitutive laws, we show that the model geometry is sufficiently detailed to simulate the complex surface displacements pattern.

  14. Hydrological Interpretation of ERT Monitoring Data on active landslides by implementation of numerical modelling at sites of the LAMOND Long-Term Landslide Monitoring Network

    NASA Astrophysics Data System (ADS)

    Hoyer, Stefan; Ottowitz, David; Supper, Robert; Jochum, Birgit; Riegler, Monika; Scolobig, Anna; Pfeiler, Stefan

    2016-04-01

    Five landslides are monitored in the framework of the LAMOND Network using Electrical Resistivity Tomography (ERT), three of these are located in Austria, one in Italy and one in France. Hydrological interpretation of the collected ERT data is typically carried out qualitatively on a visual basis. In this study, numerical modelling in combination with parameter estimation is implemented to build a basis for an enhanced interpretation. Parameter estimation is carried out by Comsol Multiphysics using Richard's equation and the Optimization module. The result of the forward model (water saturation) is compared to the ERT section (resistivity) using Archies law. The study LAMOND is funded by the Austrian Academy of sciences.

  15. 3-Dimensional numerical study of cooling performance of a heat sink with air-water flow through mini-channel

    NASA Astrophysics Data System (ADS)

    Majumder, Sambit; Majumder, Abhik; Bhaumik, Swapan

    2016-07-01

    The present microelectronics market demands devices with high power dissipation capabilities having enhanced cooling per unit area. The drive for miniaturizing the devices to even micro level dimensions is shooting up the applied heat flux on such devices, resulting in complexity in heat transfer and cooling management. In this paper, a method of CPU processor cooling is introduced where active and passive cooling techniques are incorporated simultaneously. A heat sink consisting of fins is designed, where water flows internally through the mini-channel fins and air flows externally. Three dimensional numerical simulations are performed for large set of Reynolds number in laminar region using finite volume method for both developing flows. The dimensions of mini-channel fins are varied for several aspect ratios such as 1, 1.33, 2 and 4. Constant temperature (T) boundary condition is applied at heat sink base. Channel fluid temperature, pressure drop are analyzed to obtain best cooling option in the present study. It has been observed that as the aspect ratio of the channel decreases Nusselt number decreases while pressure drop increases. However, Nusselt number increases with increase in Reynolds number.

  16. Numerical simulation of the December 4, 2007 landslide-generated tsunami in Chehalis Lake, Canada

    NASA Astrophysics Data System (ADS)

    Wang, Jiajia; Ward, Steven N.; Xiao, Lili

    2015-04-01

    On December 4, 2007, a three million cubic metres landslide impacted Chehalis Lake, 80 km east of Vancouver, Canada. The failed mass rushed into the lake and parented a tsunami that ran up 38 m on the opposite shore, destroyed trees, roads and campsite facilities. Armed with field surveys and multihigh-tech observations from SONAR, LiDAR and orthophotographs, we apply the newly developed `Tsunami Squares' method to simulate the Chehalis Lake landslide and its generated tsunami. The landslide simulation shows a progressive failure, flow speeds up to ˜60 m s-1, and a slide mass stoppage with uniform repose angle on the lakebed. Tsunami products suggest that landslide velocity and spatial scale influence the initial wave size, while wave energy decay and inundation heights are affected by a combination of distance to the landslide, bathymetry and shoreline orientation relative to the wave direction.

  17. PREDICTING TSUNAMIS GENERATED BY 3D GRANULAR LANDSLIDES

    NASA Astrophysics Data System (ADS)

    Mohammed, F.; Fritz, H. M.

    2009-12-01

    slower in propagation. Energy conversion rates between the slide motions and the generated wave trains were quantified. PIV provided instantaneous surface velocity vector fields, which gave insight into the kinematics of the landslide and wave generation process. At high impact velocities flow separation occurred on the slide shoulder resulting in a hydrodynamic impact crater. The slide characteristics measured in the experiment provide the landslide source for numerical landslide tsunami modeling. The measured landslide and tsunami data serve the validation and advancement of 3-dimensional numerical landslide tsunami and prediction models. Granular landslide tsunami generator deployed in the 3-dimensional NEES Tsunami Wave Basin at OSU.

  18. Application of a characteristic periods-based (CPB) approach to estimate earthquake-induced displacements of landslides through dynamic numerical modelling

    NASA Astrophysics Data System (ADS)

    Martino, S.; Lenti, L.; Delgado, J.; Garrido, J.; Lopez-Casado, C.

    2016-07-01

    The interaction between seismic waves and slopes is an important topic to provide reliable scenarios for earthquake-(re)triggered landslides. The physical properties of seismic waves as well as slope topography and geology can significantly modify the local seismic response, influencing landslide triggering. A novel approach is here applied to two case studies in Andalusia (southern Spain) for computing the expected earthquake-induced displacements of existing landslide masses. Towards this aim, dynamic stress-strain numerical modelling was carried out using a selection of seismic signals characterized by different spectral content and energy. In situ geophysical measurements, consisting of noise records and temporary seismometric arrays, were carried out to control the numerical outputs in terms of local seismic response. The results consist of relationships between the characteristic period, Tm, of the seismic signals and the characteristic periods of the landslide masses, related to the thickness (Ts) and length (Tl), respectively. These relationships show that the larger the horizontal dimension (i.e. length of landslide) of a landslide is, the more effective the contribution (to the resulting coseismic displacement) of the long-period seismic waves is, as the maximum displacements are expected for a low Tm at each energy level of the input. On the other hand, when the local seismic response mainly depends on stratigraphy (i.e. landslide thickness), the maximum expected displacements occur close to the resonance period of the landslide, except for high-energy seismic inputs.

  19. Application of a Characteristic Periods-Based (CPB) approach to estimate earthquake-induced displacements of landslides through dynamic numerical modelling

    NASA Astrophysics Data System (ADS)

    Martino, S.; Lenti, L.; Delgado, J.; Garrido, J.; Casado, C. Lopez

    2016-04-01

    The interaction between seismic waves and slope is an important topic to provide reliable scenarios for earthquake-(re)triggered landslides. The physical properties of seismic waves as well as slope topography and geology can significantly modify the local seismic response, influencing landslide triggering. A novel approach is here applied to two case studies in Andalusia (southern Spain) for computing the expected earthquake-induced displacements of existing landslide masses. Towards this aim, dynamic stress-strain numerical modelling was carried out using a selection of seismic signals characterized by different spectral content and energy. In situ geophysical measurements, consisting of noise records and temporary seismometric arrays, were carried out to control the numerical outputs in terms of the local seismic response. The results consist of relationships between the characteristic period, Tm, of the seismic signals and the characteristic periods of the landslide masses, related to the thickness (Ts) and length (Tl), respectively. These relationships show that the larger the horizontal dimension (i.e., length of landslide) of a landslide is, the more effective the contribution (to the resulting co-seismic displacement) of the long-period seismic waves is, as the maximum displacements are expected for a low Tm at each energy level of the input. On the other hand, when the local seismic response mainly depends on stratigraphy (i.e., landslide thickness), the maximum expected displacements occur close to the resonance period of the landslide, except for high-energy seismic inputs.

  20. Global sensitivity analysis of complex numerical landslide models based on Gaussian-Process meta-modelling

    NASA Astrophysics Data System (ADS)

    Rohmer, J.; Foerster, E.

    2012-04-01

    Large-scale landslide prediction is typically based on numerical modeling, with computer codes generally involving a large number of input parameters. Addressing the influence of each of them on the final result and providing a ranking procedure may be useful for risk management purposes, especially to guide future lab or in site characterizations and studies, but also to simplify the model by fixing the input parameters, which have negligible influence. Variance-based global sensitivity analysis relying on the Sobol' indices can provide such valuable information and presents the advantages of exploring the sensitivity to input parameters over their whole range of variation (i.e. in a global manner), of fully accounting for possible interaction between them and of being applicable without introducing a priori assumptions on the mathematical formulation of the landslide model. Nevertheless, such analysis require a large number of computer code simulations (typically a thousand), which appears impracticable for computationally demanding simulations, with computation times ranging from several hours to several days. To overcome this difficulty, we propose a ''meta-model''-based strategy consisting in replacing the complex simulator by a "costless-to-evaluate" statistical approximation (i.e. emulator) provided by a Gaussian-Process (GP) model. This allows computation of sensitivity measures from a limited number of simulations. This meta-modelling strategy is demonstrated on two cases. The first application is a simple analytical model based on the infinite slope analysis, which allows to compare the sensitivity measures computed using the ''true'' model with those computed using the GP meta-model. The second application aims at ranking in terms of importance the properties of the elasto-plastic model describing the complex behaviour of the slip surface in the "La Frasse" landslide (Switzerland). This case is more challenging as a single simulation requires at least 4

  1. The influence of the topography on landslide's mobility in Valles Marineris (Mars), by a numerical & remote sensing approach

    NASA Astrophysics Data System (ADS)

    Lucas, A.; Mangeney, A.

    Landslides play a major role in the erosion processes and transport at the surface of the Earth and Mars. Indeed, the dynamics of the landscapes is strongly tributary of these catastrophic events which also constitute important risks for the populations on Earth. It is thus advisable to study their dynamics. In addition, water often takes part in the dynamics of these events on Earth. Former work highlights a very great mobility of the gravitational flows over Mars [1] [2] [3]. The studies of martians landslides contribute to understand the dynamics of the landscapes and also teach us about climate conditions during those events occurring at Amazonian Time [4] as the potential presence of ground water. Currently, there is no unified theory for describing the landslides at the field scale. The description of granular flows is quiet well understood at the microscopic scale using various experimental and numerical experiments. But at the macroscopic scale, description remains today a largely open and wide problem. Dry granular flows experiments on an horizontal plane [5] present several differences with martians data [7]. Runout of martians landslides are twice larger than in experiments. Numerical studies in agreement with experiments scaling laws using a numerical model developped by F. Bouchut and A. Mangeney [6] based on Saint-Venant equations is proposed. Our studies focus on the influence of the topography on landslide's mobility occuring in Valles Marineris. To start with MOLA/MGS DEM data, it is also possible to rebuild the paleotopography using remote sensing methods for identification of landslide deposits. We use HRSC/MeX, THEMIS/MO and MOC/MGS images to find out correctly each area of deposits in our DEM. Afterwards, we perfom a series of numerical experiments to model landslides over a real topography rebuilt from MOLA grid. Our results show that the topography is a main parameter which contribute significantly to increase the mobility of granular flows

  2. Characteristics of tsunamis generated by 3D deformable granular landslides

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    shallow to deep water depth regime. The energy conversion between landslide and waves is lower compared with 2D and solid block landslides due to radial spread of unidirectional landslide energy by the wave front. The slide characteristics measured in the experiment provide the landslide source for numerical landslide tsunami modeling. The measured landslide and tsunami data serve the validation and advancement of 3-dimensional numerical landslide tsunami and prediction models. Landslide impact and tsunami generation (Photo credit: Devin K. Daniels)

  3. The Tsaoling 1941 Landslide, New Insight of Numerical Simulation of Discrete Element Model

    NASA Astrophysics Data System (ADS)

    Tang, C.-L.; Hu, J.-C.; Lin, M.-L.

    2009-04-01

    Large earthquakes in the southeastern Taiwan are not rare in the historical catalogue. Tsaoling, located southeast of Taiwan, last five large landslides occurred in the 19th and 20th centuries. According to the literature about the Tsaoling landslide, we concluded four characteristics of the Tsaoling landslide, (1) repeated (2) multi-landslide surface, (3) huge landslide block, and (4) some people survived after sliding a long distance (>2 km). This is the reason why we want to understand the causes of the repeated landslides in Tsaoling and its mechanisms. However, there is not any record about the landslide in 1862 and the most of the landslide evidence disappeared. Hence, we aim at the landslide dynamics of the 1941 landslide in this study. Tsaoling area is located in a large dipping towards the south-southwest monocline. The dip of strata toward the SSW is similar to the both sides of the Chinshui River valley. The bedrock of the Tsaoling area is Pliocene in age and belongs to the upper Chinshui Shale and the lower Cholan Formation. The plane failure analysis and Newmark displacement method are common for slope stability in recent years. However, the plane failure analysis can only provide a safety factor. When the safe factor (FS) is less than 1, it can only indicate that the slope is unstable. The result of Newmark displacement method is a value of displacement length. Both assumptions of the analysis are based on a rigid body. For the large landslide, like the Tsaoling landslide, the volume of landslide masses are over 108 m3, and the landslide block cannot be considered a rigid body. We considered the block as a quasi-rigid body, because the blocks are deformable and jointed. The original version of Distinct Element Method (DEM) was devoted to the modeling of rock-block systems and it was lately applied to the modeling of granular material. The calculation cycle in PFC2D is a time-stepping algorithm that consists of the repeated application of the law of

  4. Tsunamis generated by unconfined deformable granular landslides in various topographic configurations

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    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.

  5. 3D Numerical Optimization Modelling of Ivancich landslides (Assisi, Italy) via integration of remote sensing and in situ observations.

    NASA Astrophysics Data System (ADS)

    Castaldo, Raffaele; De Novellis, Vincenzo; Lollino, Piernicola; Manunta, Michele; Tizzani, Pietro

    2015-04-01

    The new challenge that the research in slopes instabilities phenomena is going to tackle is the effective integration and joint exploitation of remote sensing measurements with in situ data and observations to study and understand the sub-surface interactions, the triggering causes, and, in general, the long term behaviour of the investigated landslide phenomenon. In this context, a very promising approach is represented by Finite Element (FE) techniques, which allow us to consider the intrinsic complexity of the mass movement phenomena and to effectively benefit from multi source observations and data. In this context, we perform a three dimensional (3D) numerical model of the Ivancich (Assisi, Central Italy) instability phenomenon. In particular, we apply an inverse FE method based on a Genetic Algorithm optimization procedure, benefitting from advanced DInSAR measurements, retrieved through the full resolution Small Baseline Subset (SBAS) technique, and an inclinometric array distribution. To this purpose we consider the SAR images acquired from descending orbit by the COSMO-SkyMed (CSK) X-band radar constellation, from December 2009 to February 2012. Moreover the optimization input dataset is completed by an array of eleven inclinometer measurements, from 1999 to 2006, distributed along the unstable mass. The landslide body is formed of debris material sliding on a arenaceous marl substratum, with a thin shear band detected using borehole and inclinometric data, at depth ranging from 20 to 60 m. Specifically, we consider the active role of this shear band in the control of the landslide evolution process. A large field monitoring dataset of the landslide process, including at-depth piezometric and geological borehole observations, were available. The integration of these datasets allows us to develop a 3D structural geological model of the considered slope. To investigate the dynamic evolution of a landslide, various physical approaches can be considered

  6. Local Tsunami Hazard In The Marquesas Islands (french Polynesia) : Numerical Modeling of The 1999 Fatu Hiva Landslide and Tsunami

    NASA Astrophysics Data System (ADS)

    Hébert, H.; Schindelé, F.; Heinrich, P.; Piatanesi, A.; Okal, E. A.

    In French Polynesia, the Marquesas Islands are particularly prone to amplification of tsunamis generated at the Pacific Rim, due to relatively mild submarine slopes and to large open bays not protected by any coral reef. These islands are also threatened by local tsunamis, as shown by the recent 1999 event on Fatu Hiva. On September 13, 1999, Omoa Bay was struck by 2 to 5 m high water waves: several buildings, among them the school, were flooded and destroyed but no lives were lost. Observations gath- ered during a post-event survey revealed the recent collapse into the sea of a 300x300 m, at least 20-m thick, cliff located 5 km southeast of Omoa. This cliff failure most certainly triggered the tsunami waves since the cliff was reported intact 45 min earlier. We simulate the tsunami generation due to a subaerial landslide, using a finite- difference model assimilating the landslide to a flow of granular material. Numerical modeling shows that a 0.0024-km3 landslide located in the presumed source area ac- counts well for the tsunami waves reported in Omoa Bay. We show that the striking amplification observed in Omoa Bay is related to the trapping of waves due to the shallow submarine shelf surrounding the island. These results stress the local tsunami hazard that should be taken into account in the natural hazard assessment and mitiga- tion of the area, where historical cliff collapses can be observed and should happen again.

  7. The 2014 Lake Askja rockslide tsunami - optimization of landslide parameters comparing numerical simulations with observed run-up

    NASA Astrophysics Data System (ADS)

    Sif Gylfadóttir, Sigríður; Kim, Jihwan; Kristinn Helgason, Jón; Brynjólfsson, Sveinn; Höskuldsson, Ármann; Jóhannesson, Tómas; Bonnevie Harbitz, Carl; Løvholt, Finn

    2016-04-01

    The Askja central volcano is located in the Northern Volcanic Zone of Iceland. Within the main caldera an inner caldera was formed in an eruption in 1875 and over the next 40 years it gradually subsided and filled up with water, forming Lake Askja. A large rockslide was released from the Southeast margin of the inner caldera into Lake Askja on 21 July 2014. The release zone was located from 150 m to 350 m above the water level and measured 800 m across. The volume of the rockslide is estimated to have been 15-30 million m3, of which 10.5 million m3 was deposited in the lake, raising the water level by almost a meter. The rockslide caused a large tsunami that traveled across the lake, and inundated the shores around the entire lake after 1-2 minutes. The vertical run-up varied typically between 10-40 m, but in some locations close to the impact area it ranged up to 70 m. Lake Askja is a popular destination visited by tens of thousands of tourists every year but as luck would have it, the event occurred near midnight when no one was in the area. Field surveys conducted in the months following the event resulted in an extensive dataset. The dataset contains e.g. maximum inundation, high-resolution digital elevation model of the entire inner caldera, as well as a high resolution bathymetry of the lake displaying the landslide deposits. Using these data, a numerical model of the Lake Askja landslide and tsunami was developed using GeoClaw, a software package for numerical analysis of geophysical flow problems. Both the shallow water version and an extension of GeoClaw that includes dispersion, was employed to simulate the wave generation, propagation, and run-up due to the rockslide plunging into the lake. The rockslide was modeled as a block that was allowed to stretch during run-out after entering the lake. An optimization approach was adopted to constrain the landslide parameters through inverse modeling by comparing the calculated inundation with the observed run

  8. Integrated numerical modeling of a landslide early warning system in a context of adaptation to future climatic pressures

    NASA Astrophysics Data System (ADS)

    Khabarov, Nikolay; Huggel, Christian; Obersteiner, Michael; Ramírez, Juan Manuel

    2010-05-01

    Mountain regions are typically characterized by rugged terrain which is susceptible to different types of landslides during high-intensity precipitation. Landslides account for billions of dollars of damage and many casualties, and are expected to increase in frequency in the future due to a projected increase of precipitation intensity. Early warning systems (EWS) are thought to be a primary tool for related disaster risk reduction and climate change adaptation to extreme climatic events and hydro-meteorological hazards, including landslides. An EWS for hazards such as landslides consist of different components, including environmental monitoring instruments (e.g. rainfall or flow sensors), physical or empirical process models to support decision-making (warnings, evacuation), data and voice communication, organization and logistics-related procedures, and population response. Considering this broad range, EWS are highly complex systems, and it is therefore difficult to understand the effect of the different components and changing conditions on the overall performance, ultimately being expressed as human lives saved or structural damage reduced. In this contribution we present a further development of our approach to assess a landslide EWS in an integral way, both at the system and component level. We utilize a numerical model using 6 hour rainfall data as basic input. A threshold function based on a rainfall-intensity/duration relation was applied as a decision criterion for evacuation. Damage to infrastructure and human lives was defined as a linear function of landslide magnitude, with the magnitude modelled using a power function of landslide frequency. Correct evacuation was assessed with a ‘true' reference rainfall dataset versus a dataset of artificially reduced quality imitating the observation system component. Performance of the EWS using these rainfall datasets was expressed in monetary terms (i.e. damage related to false and correct evacuation). We

  9. Numerical investigation of the 6 February 1783 landslide-induced tsunami in Scilla (Italy)

    NASA Astrophysics Data System (ADS)

    Zaniboni, Filippo; Armigliato, Alberto; Tinti, Stefano

    2016-04-01

    The seismic crisis that struck Calabria (Southern Italy) in the period 1783-1785 is one of the most studied and documented in the Italian seismic catalogues, both for its exceptional length and for its death and damage toll. In the first two months, from February to March 1783, as many as 5 massive tsunamigenic earthquakes took place in the region. Tsunami effects resulted to be usually minor if compared to consequences of the earthquakes, with one exception. After the shock of February 6th, a large subaerial portion of Mount Pacì collapsed into the sea, provoking a local tsunami that attacked the village of Scilla, less than 1 km far. Unfortunately, almost all of the town population had gathered in the shore to escape far from buildings crashes caused by frequent earthquake shocks. The result was that about 1500 persons died, caught by up to 9 m waves flooding the low beach of Marina Grande. The waves affected also the surrounding coasts of Calabria, and the coasts of Sicily on the opposite side of the Messina Straits. Some marine surveys, performed in 2005 and 2006, characterized the morphology of the offshore area, supporting the existence of an underwater depression, continuing the already evident subaerial scar, and describing a submarine mass deposit, made of huge blocks, at about 300 m b.s.l., that can be associated with the sliding event. The exact amount of the involved volume is still a matter of investigation and it ranges from 6 million m3 (considering only the subaerial scar) to 9 million m3 (by further adding the contribution from filling the submarine depression). The two possible (minimum and maximum) scenarios are here investigated by means of numerical simulation codes, UBO-BLOCK and UBO-TSUFD, modelling the landslide and the generated tsunami respectively. The scenarios are compared and evaluated against the large amount of available and valuable historical observations that are particularly abundant and detailed for the Marina Grande area. This

  10. Numerical Modelling of Tsunamis Generated by Hypothetical Landslides in the Strait of Georgia, British Columbia

    NASA Astrophysics Data System (ADS)

    Rabinovich, A. B.; Thomson, R. E.; Bornhold, B. D.; Fine, I. V.; Kulikov, E. A.

    A modified and corrected version of the viscous slide model of Jiang and LeBlond (1994) is used to assess the tsunami risk associated with hypothetical underwater slope failures in two coastal areas of British Columbia having potentially unstable sediment deposits: (a) Malaspina Strait, separating the mainland coast and Texada Island in the central Strait of Georgia; and (b) Roberts Bank on the foreslope of the Fraser River Delta in the southern Strait of Georgia. The intent of this study is to demonstrate the capability of the model for tsunami risk assessment and to improve upon previous studies of tsunami risk in the region based on reasonable submarine landslide scenarios. The potential risk from tsunamis associated with slide failures has been examined, but the likelihood of failure events themselves was not considered. For the Malaspina Strait scenarios, simulated tsunamis are generated by failure of a lobe of perched sediment situ ated on the slope of eastern Texada Island. Failure as a flow slide of the estimated 1,250,000 m3 of sediment generates wave troughs reaching -4.9 m and trough-to-crest heights of 6 to 8 m along the coast of Texada Island. At Cape Cockburn, on the opposite side of the strait, wave heights of 1.5 to 2.0 m are produced. For Roberts Bank, simulated waves are examined for two separate failure scenarios. The larger slide (Case 1) involves the failure of a sediment lobe with lateral dimensions of 7 × 3 km2 and volume of 0.75 km3 while the smaller slide (Case 2) fails a sediment lobe with dimensions of 4 × 2.6 km2 and volume of 0.23 km3. Computations were made both for high (+3 m) and low (-3 m) tide conditions. For both failure volumes, maximum wave amplitudes (up to 18 m for Case 1 and 8 m for Case 2) occur on the coasts of Mayne and Galiano Islands, opposite the source area. Wave amplitudes are much smaller (1 to 4 m) on the mainl and coast because of the reflection of the initial waves from Roberts Bank. Additional numerical

  11. Do landslides follow landslides?

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Landslide susceptibility maps are typically obtained by quantifying relations between landslides and conditioning attributes. Here, we take a fundamentally different starting point: path dependency and self-organization, i.e. the effect of landslides on landslides. We test two hypotheses: first, that landslides do preferentially follow landslides, and second, that follow-up landslides are different from those that do not follow other slides. Results indicate that there is indeed a considerable amount of overlap among landslides that affect the overall affected area by landsliding. This is more than expected: the number of overlaps among landslides is more than would occur of slides were randomly placed in the study area. Overlaps of slides with previous slides occur frequently within a period of about ten years after a previous slide, yet decrease considerably over time. Also the second hypothesis is confirmed: follow-up landslides indeed have different properties in terms of power law and shape than those that are not associated. Particularly, follow-up landslides are larger and more elongated than non-follow up landslides. Moreover, after fitting an inverse gamma function to the magnitude-frequency distributions of follow-up and non-follow-up slides, it was found that the alpha parameter that controls the prevalence of very extreme events, is much larger for follow-up slides than for non-follow-up slides. Also the rollover value is substantially larger for follow-up landslides than non-follow up landslides . The prevalence of follow-up slides in the first approximately ten years after a previous slides, and the fact that follow-up slides are different from other slides, should have implications for susceptibility studies. Apparently, susceptibility (conventionally a purely spatial concept) changes with the time since previous landslides happened. We explore possible mechanisms for this that may allow us to include these temporal changes in landslide

  12. Numerical modeling of submarine landslide-generated tsunamis as a component of the Alaska Tsunami Inundation Mapping Project

    USGS Publications Warehouse

    Suleimani, E.; Lee, H.; Haeussler, Peter J.; Hansen, R.

    2006-01-01

    Tsunami waves are a threat for manyAlaska coastal locations, and community preparedness plays an important role in saving lives and property. The GeophysicalInstitute of the University of Alaska Fairbanks participates in the National Tsunami Hazard Mitigation Program by evaluating andmapping potential tsunami inundation of selected coastal communities in Alaska. We develop hypothetical tsunamiscenarios based on the parameters of potential underwater earthquakes and landslides for a specified coastal community. The modeling results are delivered to the community for localtsunami hazard planning and construction of evacuation maps. For the community of Seward, located at the head of Resurrection Bay, tsunami potential from tectonic and submarinelandslide sources must be evaluated for comprehensiveinundation mapping. Recent multi-beam and high-resolution sub-bottom profile surveys of Resurrection Bay show medium- and large-sized blocks, which we interpret as landslide debris that slid in the 1964 earthquake. Numerical modeling of the 1964 underwater slides and tsunamis will help to validate and improve the models. In order to construct tsunami inundation maps for Seward, we combine two different approaches for estimating tsunami risk. First, we observe inundation and runup due to tsunami waves generated by the 1964 earthquake. Next we model tsunami wave dynamics in Resurrection Bay caused by superposition of the local landslide- generated waves and the major tectonic tsunami. We compare modeled and observed values from 1964 to calibrate the numerical tsunami model. In our second approach, we perform a landslide tsunami hazard assessment using underwater slope stability analysis and available characteristics of potentially unstable sediment bodies. The approach produces hypothetical underwater slides and resulting tsunami waves. We use a three-dimensional numerical model of an incompressible viscous slide with full interaction between the slide

  13. Numerical investigations of triggering mechanisms of shallow landslides due to heterogeneous spatio-temporal hydrological patterns.

    NASA Astrophysics Data System (ADS)

    Schwarz, Massimiliano; Cohen, Denis

    2016-04-01

    Rainfall is one of the major triggering factor of shallow landslide around the world. The increase of soil moisture in the soil influences the stability of a slope through the increase of soil bulk density, the reduction of soil apparent cohesion (due to suction stress), and the increase in pore water pressure.The spatio-temporal transformations of such properties of soil are know to be heterogeneous and under constant change. For instance, there may be a condition where, in cracked clay-soil, water, during a rain event, produces a rapid increase of pore water pressure along preferential flow-paths (crack or roots), while soil moisture and suction within the soil matrix change minimally. An another site in a sandy soil, the situation might be very different where the increase of soil moisture and pore water pressure, and the decrease of soil suction take place more or less simultaneously across the entire soil profile. In both of these cases topography plays a major role in determining the accumulation of water along the slope through different subsurface flows intensities and directions. In many documented cases in the Alps, shallow landslides may also be triggered by the punctual exfiltration of water from bedrock or weathered geological strata. The hydro-geological characteristics of the catchment control this mechanism. These different situations aim to give an idea of the large spectrum of hydrological triggering conditions of shallow landslides. The heterogeneities of these hydrological conditions represent a difficult issue in modeling shallow landslide triggering mechanisms. In the simplest models, hydrology is assumed to influence changes in pore water pressure only, mostly using one dimensional vertical infiltration models. More advanced models consider changes in apparent cohesion due to changes in soil moisture or include more complex hydrological models to simulate water flow and distribution during a rainfall event. However, most models at the

  14. Numerical modelling of rapid, flow-like landslides across 3-D terrains: a Tsunami Squares approach to El Picacho landslide, El Salvador, September 19, 1982

    NASA Astrophysics Data System (ADS)

    Wang, Jiajia; Ward, Steven N.; Xiao, Lili

    2015-06-01

    Flow-like landslides are rapidly moving fluid-solid mixtures that can cause significant destruction along paths that run far from their original sources. Existing models for run out prediction and motion simulation of flow-like landslides have many limitations. In this paper, we develop a new method named `Tsunami Squares' to simulate the generation, propagation and stoppage of flow-like landslides based on conservation of volume and momentum. Landslide materials in the new method form divisible squares that are displaced, then further fractured. The squares move under the influence of gravity-driven acceleration and suffer decelerations due to basal and dynamic frictions. Distinctively, this method takes into account solid and fluid mechanics, particle interactions and flow regime transitions. We apply this approach to simulate the 1982 El Picacho landslide in San Salvador, capital city of El Salvador. Landslide products from Tsunami Squares such as run out distance, velocities, erosion and deposition depths and impacted area agree well with field investigated and eyewitness data.

  15. Numerical modelling of slow landslides through the exploitation of DInSAR and inclinometric measurements: the Ivancich case study (Assisi, Central Italy)

    NASA Astrophysics Data System (ADS)

    Castaldo, Raffaele; Lollino, Piernicola; Tizzani, Pietro; Ardizzone, Francesca; Calò, Fabiana; Guzzetti, Fausto; Manunta, Michele; Manzo, Mariarosaria

    2013-04-01

    Risk management of slow landslides requires both the assessment of slope stability conditions and the analysis of the dynamic evolution in terms of displacement, velocity or acceleration during the deformation phase. To this purpose, we analysed the kinematical evolution of a slow landslides through a numerical model implemented in Finite Element Environment (FEE) and compared with monitoring data based on DInSAR interferometry technique and conventional inclinometric investigation. In our study we analyse the Ivancich slow landslide (Assisi, Central Italy). The landslide body is formed of detritus (or debris) material sliding on a arenaceous marl substratum, with a thin shear band detected using borehole and inclinometric data, at depth ranging from 20 to 60 m. Specifically, we considered the active role of this shear band in the control of the landslide evolution process. Ground surface displacement measurements have been also retrieved via an advanced space-based Differential SAR interferometry analysis. ERS-1/2 and ENVISAT SAR images taken in the 1992-2010 period have been used to generate long time-series showing the temporal evolution of surface movements of the unstable slope, that indicate different displacement rates for the various portions of the landslide body. A large field monitoring dataset of the landslide process, including at-depth piezometric and inclinometric measurements acquired in the last decade all over the landslide body, was available to us. The piezometric data do not show appreciable variation of the pore water pressures at the level of the sliding surface. We performed a two-dimensional time-dependent Finite Element Model (FEM) of the active ground deformation field aimed at simulating the kinematical evolution of the different sectors of the unstable mass. In particular, a deviatoric creep law, accounting for a time dependent shear deformation over constant deviatoric stress, has been used to describe the shear band behavior. An

  16. Comparison of the Structurally Controlled Landslides Numerical Model Results to the M 7.2 2013 Bohol Earthquake Co-seismic Landslides

    NASA Astrophysics Data System (ADS)

    Macario Galang, Jan Albert; Narod Eco, Rodrigo; Mahar Francisco Lagmay, Alfredo

    2015-04-01

    The M 7.2 October 15, 2013 Bohol earthquake is the most destructive earthquake to hit the Philippines since 2012. The epicenter was located in Sagbayan municipality, central Bohol and was generated by a previously unmapped reverse fault called the "Inabanga Fault". Its name, taken after the barangay (village) where the fault is best exposed and was first seen. The earthquake resulted in 209 fatalities and over 57 billion USD worth of damages. The earthquake generated co-seismic landslides most of which were related to fault structures. Unlike rainfall induced landslides, the trigger for co-seismic landslides happen without warning. Preparedness against this type of landslide therefore, relies heavily on the identification of fracture-related unstable slopes. To mitigate the impacts of co-seismic landslide hazards, morpho-structural orientations or discontinuity sets were mapped in the field with the aid of a 2012 IFSAR Digital Terrain Model (DTM) with 5-meter pixel resolution and < 0.5 meter vertical accuracy. Coltop 3D software was then used to identify similar structures including measurement of their dip and dip directions. The chosen discontinuity sets were then keyed into Matterocking software to identify potential rock slide zones due to planar or wedged discontinuities. After identifying the structurally-controlled unstable slopes, the rock mass propagation extent of the possible rock slides was simulated using Conefall. The results were compared to a post-earthquake landslide inventory of 456 landslides. Out the total number of landslides identified from post-earthquake high-resolution imagery, 366 or 80% intersect the structural-controlled hazard areas of Bohol. The results show the potential of this method to identify co-seismic landslide hazard areas for disaster mitigation. Along with computer methods to simulate shallow landslides, and debris flow paths, located structurally-controlled unstable zones can be used to mark unsafe areas for settlement. The

  17. Estimation of Dynamic Friction Process of the Akatani Landslide Based on the Waveform Inversion and Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Yamada, M.; Mangeney, A.; Moretti, L.; Matsushi, Y.

    2014-12-01

    Understanding physical parameters, such as frictional coefficients, velocity change, and dynamic history, is important issue for assessing and managing the risks posed by deep-seated catastrophic landslides. Previously, landslide motion has been inferred qualitatively from topographic changes caused by the event, and occasionally from eyewitness reports. However, these conventional approaches are unable to evaluate source processes and dynamic parameters. In this study, we use broadband seismic recordings to trace the dynamic process of the deep-seated Akatani landslide that occurred on the Kii Peninsula, Japan, which is one of the best recorded large slope failures. Based on the previous results of waveform inversions and precise topographic surveys done before and after the event, we applied numerical simulations using the SHALTOP numerical model (Mangeney et al., 2007). This model describes homogeneous continuous granular flows on a 3D topography based on a depth averaged thin layer approximation. We assume a Coulomb's friction law with a constant friction coefficient, i. e. the friction is independent of the sliding velocity. We varied the friction coefficients in the simulation so that the resulting force acting on the surface agrees with the single force estimated from the seismic waveform inversion. Figure shows the force history of the east-west components after the band-pass filtering between 10-100 seconds. The force history of the simulation with frictional coefficient 0.27 (thin red line) the best agrees with the result of seismic waveform inversion (thick gray line). Although the amplitude is slightly different, phases are coherent for the main three pulses. This is an evidence that the point-source approximation works reasonably well for this particular event. The friction coefficient during the sliding was estimated to be 0.38 based on the seismic waveform inversion performed by the previous study and on the sliding block model (Yamada et al., 2013

  18. Numerical analysis of the creeping behavior of the S. Andrea di Perarolo secondary landslide (Italian Eastern Alps)

    NASA Astrophysics Data System (ADS)

    Cioli, C.; Genevois, R.; Iafelice, M.; Zorzi, L.

    2012-04-01

    The S. Andrea landslide is a complex secondary phenomenon characterized by continuous movements causing a very high hazard condition for the near Perarolo di Cadore village (Italian Eastern Alps). A significant amount of geological and geotechnical investigations has been carried out in the past allowing the detection of the basal sliding surface. In specific, the sliding surface coincides with the contact between the bedrock and the overlying mass of an old landslides, involving a volume of about 180.000 cubic meters. A numerical approach has been adopted to analyze the stability of slope. This method is able to simulate the formation and development of shear zones as areas of strain localization in the model. Indeed, the S. Andrea landslide has been, then, investigated using FLAC, a two-dimensional explicit finite difference program, particularly useful in case of slopes with complex geometry. In order to build up a suitable model, variation of geological, hydrogeological and geotechnical parameters have been identified from the interpretation of all available data. In a preliminary stage, a Mohr-Coulomb plasticity model has been adopted except for the bedrock, which was characterized by an isotropic elastic model. Groundwater flow condition has been performed evaluating the change in pore pressure coupled to the mechanical deformation calculation. Numerical results show that this model cannot simulate real displacement behavior of the slope mainly due to both the complex material behavior and lithological heterogeneity, and due to geotechnical spatial complexity of different soils and mechanical parameters. It has been assumed that it was necessary to improve the model in the light of a time dependent behavior of existing soils. An elastic-viscoplastic model has been then used to reproduce the observed creeping behavior, and only in viscoplastic region time effects have been considered. Discussion of results points out on: i) the evolution of the ``mechanical

  19. Prediction of Tsunami Waves and Runup Generated by 3d Granular Landslides

    NASA Astrophysics Data System (ADS)

    Mohammed, F.; Fritz, H. M.

    2008-12-01

    attenuation. The measured wave speed of the leading wave corresponds well to the theoretical approximation of the solitary wave speed while the trailing waves are considerably slower in nature. Attenuation functions of the leading wave crest amplitude, the wave length and the time period were obtained to study the wave behavior in the near field and far field regions. The experimental data also provided the energy conversion rate between the landslide source and the generated tsunami waves. The slide characteristics measured in the experiment provides the landslide source for numerically modeling these landslide tsunamis. The measured wave data serves the validation and advancement of 3-dimensional numerical landslide tsunami and prediction models.

  20. Physical Modeling of Landslide Generated Tsunamis in Fjords and around Conical Islands

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    Froude number and relative landslide shape among others. Energy conversion rates between the landslide motion and the generated wave train are quantified. The lateral edge wave and offshore wave propagation velocities are compared against wave theories. Unique characteristics in the wave and runup data caused by topographic and bathymetric features are analyzed. A localized amplification of the runup was observed on the lee-side of the conical island due to the collision effects of the lateral edge waves propagating around both sides of the island. The measured landslide and tsunami data serve to validate and advance 3-dimensional numerical landslide tsunami prediction models.; Tsunami generation by landslide (Photo credit: Stephanie Lopez)

  1. Exploring the Dynamics of the August 2010 Mount Meager Rock Slide-Debris Flow Jointly with Seismic Source Inversion and Numerical Landslide Modeling

    NASA Astrophysics Data System (ADS)

    Allstadt, K.; Moretti, L.; Mangeney, A.; Stutzmann, E.; Capdeville, Y.

    2014-12-01

    The time series of forces exerted on the earth by a large and rapid landslide derived remotely from the inversion of seismic records can be used to tie post-slide evidence to what actually occurred during the event and can be used to tune numerical models and test theoretical methods. This strategy is applied to the 48.5 Mm3 August 2010 Mount Meager rockslide-debris flow in British Columbia, Canada. By inverting data from just five broadband seismic stations less than 300 km from the source, we reconstruct the time series of forces that the landslide exerted on the Earth as it occurred. The result illuminates a complex retrogressive initiation sequence and features attributable to flow over a complicated path including several curves and runup against a valley wall. The seismically derived force history also allows for the estimation of the horizontal acceleration (0.39 m/s^2) and average apparent coefficient of basal friction (0.38) of the rockslide, and the speed of the center of mass of the debris flow (peak of 92 m/s). To extend beyond these simple calculations and to test the interpretation, we also use the seismically derived force history to guide numerical modeling of the event - seeking to simulate the landslide in a way that best fits both the seismic and field constraints. This allows for a finer reconstruction of the volume, timing, and sequence of events, estimates of friction, and spatiotemporal variations in speed and flow thickness. The modeling allowed us to analyze the sensitivity of the force to the different parameters involved in the landslide modeling to better understand what can and cannot be constrained from seismic source inversions of landslide signals.

  2. Probabilistic landslide run-out assessment with a 2-D dynamic numerical model using a Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Cepeda, Jose; Luna, Byron Quan; Nadim, Farrokh

    2013-04-01

    An essential component of a quantitative landslide hazard assessment is establishing the extent of the endangered area. This task requires accurate prediction of the run-out behaviour of a landslide, which includes the estimation of the run-out distance, run-out width, velocities, pressures, and depth of the moving mass and the final configuration of the deposits. One approach to run-out modelling is to reproduce accurately the dynamics of the propagation processes. A number of dynamic numerical models are able to compute the movement of the flow over irregular topographic terrains (3-D) controlled by a complex interaction between mechanical properties that may vary in space and time. Given the number of unknown parameters and the fact that most of the rheological parameters cannot be measured in the laboratory or field, the parametrization of run-out models is very difficult in practice. For this reason, the application of run-out models is mostly used for back-analysis of past events and very few studies have attempted to achieve forward predictions. Consequently all models are based on simplified descriptions that attempt to reproduce the general features of the failed mass motion through the use of parameters (mostly controlling shear stresses at the base of the moving mass) which account for aspects not explicitly described or oversimplified. The uncertainties involved in the run-out process have to be approached in a stochastic manner. It is of significant importance to develop methods for quantifying and properly handling the uncertainties in dynamic run-out models, in order to allow a more comprehensive approach to quantitative risk assessment. A method was developed to compute the variation in run-out intensities by using a dynamic run-out model (MassMov2D) and a probabilistic framework based on a Monte Carlo simulation in order to analyze the effect of the uncertainty of input parameters. The probability density functions of the rheological parameters

  3. Numerical modelling of hydrological slope response: GIS application to rainfall induced landslides forecasting

    NASA Astrophysics Data System (ADS)

    Olivares, Lucio; Picarelli, Luciano; Savastano, Vincenzo; Damiano, Emilia; Greco, Roberto; Guida, Andrea

    2010-05-01

    A significant part of Italian mountainous areas are covered by pyroclastic deposits resting at slope angles higher than 40-50°. The stability of these steep slopes in loose or poorly cemented pyroclastic materials is essentially guaranteed by the positive effects of matrix suction on shear strength until an increase in saturation (and hence a decrease in suction) is induced by seepage initiated by different processes. The Cervinara flowslide (Campania, Italy) is a typical case where rainfall infiltration increased saturation and hence led to failure of shallow layered pyroclastic deposits. This case study is examined by means of a numerical model calibrated through back-analysis of flume tests, which link instability to rainwater infiltration. The complexity of infiltration process on unsaturated layered slope requires the set up of a numerical model. The model includes a 3D volume finite algorithm (I-MOD3D) developed in VBA application for ARCOBJECTTM/ARCGIS 9.2TM to automate the mesh-generation starting from a Digital Terrain Model allowing the analysis of slope response at catchment scale. Model calibration was carried out using either data from laboratory tests on natural soil samples or from infiltration tests on layered slope model. Model validation was carried out through back-analysis of in situ suction measurements using initial and boundary conditions derived from field monitoring. Comparison between the results of slope model infiltration tests, numerical simulations and in situ measurements showed that the developed numerical model represents reliable tool for predicting slope response to rainfall infiltration for shallow layered pyroclastic deposits.

  4. Numerical Simulation of Boiling Two-Phase Flow in Tight-Lattice Rod Bundle by 3-Dimensional Two-Fluid Model Code ACE-3D

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Misawa, Takeharu; Takase, Kazuyuki

    Two-fluid model can simulate two-phase flow by computational cost less than detailed two-phase flow simulation method such as interface tracking method or particle interaction method. Therefore, two-fluid model is useful for thermal hydraulic analysis in large-scale domain such as a rod bundle. Japan Atomic Energy Agency (JAEA) develops three dimensional two-fluid model analysis code ACE-3D that adopts boundary fitted coordinate system in order to simulate complex shape flow channel. In this paper, boiling two-phase flow analysis in a tight-lattice rod bundle was performed by ACE-3D code. The parallel computation using 126 CPUs was applied to this analysis. In the results, the void fraction, which distributes in outermost region of rod bundle, is lower than that in center region of rod bundle. The tendency of void fraction distribution agreed with the measurement results by neutron radiography qualitatively. To evaluate effects of two-phase flow model used in ACE-3D code, numerical simulation of boiling two-phase in tight-lattice rod bundle with no lift force model was also performed. From the comparison of calculated results, it was concluded that the effects of lift force model were not so large for overall void fraction distribution of tight-lattice rod bundle. However, the lift force model is important for local void fraction distribution of fuel bundles.

  5. Numerical simulation of landslide-generated waves using a soil-water coupling smoothed particle hydrodynamics model

    NASA Astrophysics Data System (ADS)

    Shi, Chuanqi; An, Yi; Wu, Qiang; Liu, Qingquan; Cao, Zhixian

    2016-06-01

    We simulate the generation of a landslide-induced impulse wave with a newly-developed soil-water coupling model in the smoothed particle hydrodynamics (SPH) framework. The model includes an elasto-plastic constitutive model for soil, a Navier-Stokes equation based model for water, and a bilateral coupling model at the interface. The model is tested with simulated waves induced by a slow and a fast landslide. Good agreement is obtained between simulation results and experimental data. The generated wave and the deformation of the landslide body can both be resolved satisfactorily. All parameters in our model have their physical meaning in soil mechanics and can be obtained from conventional soil mechanics experiments directly. The influence of the dilatancy angle of soil shows that the non-associated flow rule must be selected, and the value of the dilatancy angle should not be chosen arbitrarily, if it is not determined with relative experiments.

  6. Italian landslide early warning system

    NASA Astrophysics Data System (ADS)

    Rossi, M.

    2009-04-01

    for the early warning system, comparing rain gauge network measurements with existing and new national rainfall thresholds, has been implemented. In this version, information on landslide spatial and temporal probability at the national scale have been made available. Future versions of the system: (i) will use new Italian regional and local rainfall thresholds, (ii) will consider rainfall estimates obtained from ground-based weather radars, meteorological satellites, and numerical weather forecasts, and (iii) will implement new criteria for the issue of warning based on the combination of rainfall thresholds and statistical models of landslide hazard and risk.

  7. Investigation of Geomorphic and Seismic Effects on the 1959 Madison Canyon, Montana, Landslide Using an Integrated Field, Engineering Geomorphology Mapping, and Numerical Modelling Approach

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    We present an integrated approach to investigate the seismically triggered Madison Canyon landslide (volume = 20 Mm3), which killed 26 people in Montana, USA, in 1959. We created engineering geomorphological maps and conducted field surveys, long-range terrestrial digital photogrammetry, and preliminary 2D numerical modelling with the objective of determining the conditioning factors, mechanisms, movement behaviour, and evolution of the failure. We emphasise the importance of both endogenic (i.e. seismic) and exogenic (i.e. geomorphic) processes in conditioning the slope for failure and hypothesise a sequence of events based on the morphology of the deposit and seismic modelling. A section of the slope was slowly deforming before a magnitude-7.5 earthquake with an epicentre 30 km away triggered the catastrophic failure in August 1959. The failed rock mass rapidly fragmented as it descended the slope towards Madison River. Part of the mass remained relatively intact as it moved on a layer of pulverised debris. The main slide was followed by several debris slides, slumps, and rockfalls. The slide debris was extensively modified soon after the disaster by the US Army Corps of Engineers to provide a stable outflow channel from newly formed Earthquake Lake. Our modelling and observations show that the landslide occurred as a result of long-term damage of the slope induced by fluvial undercutting, erosion, weathering, and past seismicity, and due to the short-term triggering effect of the 1959 earthquake. Static models suggest the slope was stable prior to the 1959 earthquake; failure would have required a significant reduction in material strength. Preliminary dynamic models indicate that repeated seismic loading was a critical process for catastrophic failure. Although the ridge geometry and existing tension cracks in the initiation zone amplified ground motions, the most important factors in initiating failure were pre-existing discontinuities and seismically induced

  8. Ganges Landslide

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03681 Ganges Landslide

    Two large landslides dominate this image of part of Ganges Chasma. The eroded surface of an old landslide covers the north half of the image, while a more recent landslide occurs to the south.

    Image information: VIS instrument. Latitude -6.7N, Longitude 310.4E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. Numerical Investigation of Seismically Induced Rock Mass Fatigue as a Mechanism Contributing to the Progressive Failure of Deep-Seated Landslides

    NASA Astrophysics Data System (ADS)

    Gischig, Valentin; Preisig, Giona; Eberhardt, Erik

    2016-06-01

    The importance of earthquakes in triggering catastrophic failure of deep-seated landslides has long been recognized and is well documented in the literature. However, seismic waves do not only act as a trigger mechanism. They also contribute to the progressive failure of large rock slopes as a fatigue process that is highly efficient in deforming and damaging rock slopes. Given the typically long recurrence time and unpredictability of earthquakes, field-based investigations of co-seismic rock slope deformations are difficult. We present here a conceptual numerical study that demonstrates how repeated earthquake activity over time can destabilize a relatively strong rock slope by creating and propagating new fractures until the rock mass is sufficiently weakened to initiate catastrophic failure. Our results further show that the damage and displacement induced by a certain earthquake strongly depends on pre-existing damage. In fact, the damage history of the slope influences the earthquake-induced displacement as much as earthquake ground motion characteristics such as the peak ground acceleration. Because seismically induced fatigue is: (1) characterized by low repeat frequency, (2) represents a large amplitude damage event, and (3) weakens the entire rock mass, it differs from other fatigue processes. Hydro-mechanical cycles, for instance, occur at higher repeat frequencies (i.e., annual cycles), lower amplitude, and only affect limited parts of the rock mass. Thus, we also compare seismically induced fatigue to seasonal hydro-mechanical fatigue. While earthquakes can progressively weaken even a strong, competent rock mass, hydro-mechanical fatigue requires a higher degree of pre-existing damage to be effective. We conclude that displacement rates induced by hydro-mechanical cycling are indicative of the degree of pre-existing damage in the rock mass. Another indicator of pre-existing damage is the seismic amplification pattern of a slope; frequency

  10. SLOWMOVE - A numerical model for the propagation of slow-moving landslides: a spatially distributed 2.5D approach and its application to the analysis of the Super-Sauze landslide (French Alps).

    NASA Astrophysics Data System (ADS)

    Travelletti, Julien; Bégueria, Santiago; van Asch, Theo; Spickermann, Anke; Malet, Jean-Philippe

    2010-05-01

    Process-based models are common tools for understanding and forecasting landslide behaviour. The objective of this study is to describe the implementation of the dynamic SLOWMOVE model in 2.5 dimensions using the GIS scripting language PCRaster. This environment provides visualization of the results through map animations and time series, and a user-friendly interface. The model performance is evaluated on multi-temporal datasets of landslide displacements for the period of summer 2009. The Super-Sauze landslide is triggered in Callovo-Oxfordian black marls and is composed of a silty-sand matrix mixed with moraine debris. It extends over a horizontal distance of 850 m with an average 25° slope. The total volume is estimated at 750,000 m3 and creeping velocities range from 0.01 to 0.40 m day-1. The complex paleo-topography covered by the landslide is made by successions of crests and gullies which play an essential role in the behavior by creating sections with distinct kinematical, mechanical and hydrological characteristics. Observational data showed that the velocity rates are mainly controlled by changes in excess pore water pressure. The SLOWMOVE model has been implemented in 2.5D in order to take into account of complex basal topography represented through a DEM. The landslide is treated as a one-phase material, whose behavior is controlled by rheological properties following a Coulomb-viscous model. SLOWMOVE 2.5D is based on a two dimensional finite difference solution (2D Eulerian space with Cartesian coordinates) of the Saint Venant equations that are derived from a depth-integration of the Navier-Stokes equations of fluid motion. Important assumptions in the model are that: (1) the inertia term in the equation of motion can be cancelled without a significant effect in the velocity field; (2) the acceleration due to internal pressure is controlled by strain; (3) undrained loading generates excess pore water pressure.

  11. Landslides and debris flows in Ephraim Canyon, central Utah

    SciTech Connect

    Baum, R.L.; Fleming, R.W.

    1989-01-01

    The geology of 36 km{sup 2} in Ephraim Canyon, on the west side of the Wasatch Plateau, central Utah, was mapped at a scale of 1:12,000 following the occurrence of numerous landslides in 1983. The geologic map shows the distribution of the landslides and debris flows of 1983-86, as well as older landslide deposits, other surficial deposits, and bedrock. Several of the recent landslides are described and illustrated by means of maps or photographs.

  12. Venus - Landslide Deposits

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Magellan spacecraft has observed remnant landslide deposits apparently resulting from the collapse of volcanic structures. This image, centered at 45.2 degrees south latitude, 201.4 degrees east longitude, shows a collapse deposit 70 kilometers (43 miles) across. The bright, highly textured deposit near the center of the image probably consists of huge blocks of fractured volcanic rock, many as large as several hundred meters across. A remnant of the volcano itself, about 20 kilometers (12.4 miles) across, is seen at the center of the image. The distorted radar appearance of the volcano is a result of extremely steep slopes on the 'scars' from which the landslide material originated. A field of numerous small volcanic domes can be seen in the northern half of the image. The bright irregular lineaments trending to the north-northwest are ridges caused by regional tectonic deformation of the upper layers of the Venusian crust.

  13. Tithonium Landslide

    NASA Technical Reports Server (NTRS)

    2006-01-01

    12 February 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a large landslide deposit on the floor of western Tithonium Chasma.

    Location near: 4.3oS, 87.9oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  14. Ophir Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    4 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a small landslide off a steep slope in southwestern Ophir Chasma.

    Location near: 4.6oS, 72.8oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Spring

  15. Tharsis Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The landslide in the VIS image occurs in the Tharsis region of Mars, just north of Hebes Chasma. The volcanic flows forming the lower surface in the image have a platy texture. The landslide is younger than the volcanic flow, as the landslide sits on top of the flow surface.

    Image information: VIS instrument. Latitude 5, Longitude 282.4 East (77.6 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. Ganges Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This Mars Global Surveyor (MGS) Orbiter Camera (MOC) image shows a high resolution view of portions of the lobes of several landslide deposits in Ganges Chasma. Dark material near the bottom (south) end of the image is windblown sand.

    Location near: 8.2oS, 44.3oW Image width: 3.0 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  17. Teleportation of a 3-dimensional GHZ State

    NASA Astrophysics Data System (ADS)

    Cao, Hai-Jing; Wang, Huai-Sheng; Li, Peng-Fei; Song, He-Shan

    2012-05-01

    The process of teleportation of a completely unknown 3-dimensional GHZ state is considered. Three maximally entangled 3-dimensional Bell states function as quantum channel in the scheme. This teleportation scheme can be directly generalized to teleport an unknown d-dimensional GHZ state.

  18. Crater Landslide

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA06088 Crater Landslide

    This landslide occurs in an unnamed crater southeast of Millochau Crater.

    Image information: VIS instrument. Latitude -24.4N, Longitude 87.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Underwater Landslide Shape, Motion, Deformation, and Tsunami Generation

    NASA Astrophysics Data System (ADS)

    Grilli, S. T.; Watts, P.

    2003-04-01

    We represent underwater landslides with functional forms that describe the shape of an underwater landslide, or submarine mass failure. The chosen mathematical functions are able to reproduce most features of the more complicated landslide shapes output by the model BING. A canonical description of underwater landslide shape is proposed that remains valid throughout mass failure acceleration. The landslide motion is decomposed into center of mass motion and deformation about the center of mass, in traditional engineering fashion. The theoretical center of mass motion is compared to both experimental results of granular mass flows and numerical results from BING. Appropriate values of dynamical coefficients account for added mass effects, hydrodynamic drag, and Coulomb friction, whenever applicable. Landslide motion is scaled by landslide density, length and slope angle. This approach is readily extended to account for real bathymetric cross sections. Landslide deformation is treated as an overall landslide thinning, an overall landslide extension, and as an accumulation of bulk towards the front of the failure. The initial rates of deformation are found from both experimental and numerical work. The mean rates of deformation are found from the length of actual landslide deposits. In both cases, landslide deformation is scaled by the landslide density, length and slope angle. Tsunami generation is simulated with an efficient 2D Boundary Element Method fluid dynamic model. The model enables many different tsunami generation simulations with an absolute free surface accuracy of greater than 1%. A sensitivity analysis is performed for tsunamis generated by a substantial cross-section of the non-dimensional space described by landslide shape, motion, and deformation. Tsunami generation by the model is compared to various experimental results of solid and deforming landslides. In general, it is the center of mass motion that dominates tsunami generation, whereas

  20. Physical Modeling of Landslide Generated Tsunamis and the 50th Anniversary of the Vajont Dam Disaster

    NASA Astrophysics Data System (ADS)

    McFall, Brian C.; Mohammed, Fahad; Fritz, Hermann M.

    2013-04-01

    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 shape and front velocity were measured using above and underwater cameras. Three-dimensional landslide surfaces with surface velocities were reconstruction 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.

  1. Mount Meager landslide flow history

    NASA Astrophysics Data System (ADS)

    Moretti, L.; Allstadt, K.; Mangeney, A.; Capdeville, Y.; Stutzmann, E.; Bouchut, F.

    2013-12-01

    Gravitational instabilities, such as landslides, avalanches, or debris flows, play a key role in erosional processes and represent one of the major natural hazards in mountainous, coastal, and volcanic regions. Despite the great amount of field, experimental and numerical work devoted to this problem, the understanding of the physical processes at work in gravitational flows is still an open issue, in particular due to the lack of observations relevant to their dynamics. In this context, the seismic signal generated by gravitational flows is a unique opportunity to obtain information on their dynamics. Indeed, as shown recently by Favreau et al., (2010), simulation of the seismic signal generated by landslides makes it possible to discriminate different flow scenarios and estimate rheological parameters. Global and regional seismic networks continuously record gravitational instabilities, so this new method will help gather new data on landslide behavior, particularly when combined with a landslide numerical modeling. Using this approach, we focus on the 6 August 2010 Mount Meager landslide: a 48.5 Mm3 rockslide-debris flow occurring in the Mount Meager Volcanic complex in the Southwest British Columbia. This landslide traveled over 12.7 km in just a few minutes time and was recorded by 25 broadband seismic stations. The time history of the forces exerted by the landslide on the ground surface was inverted from the seismic waveforms. The forcing history revealed the occurrence of a complicated initiation and showed features attributable to flow over a complicated path that included two sharp turns and runup at a valley wall barrier. To reliably interpret this signal and thus obtain detailed information about the dynamics of the landslide, we ran simulations for a range of scenarios by varying the coefficient of friction and the number, mass, and timings of subevents and compute the forces generated in each case. By comparing the results of these simulations to the

  2. 3-dimensional Oil Drift Simulations

    NASA Astrophysics Data System (ADS)

    Wettre, C.; Reistad, M.; Hjøllo, B.Å.

    Simulation of oil drift has been an ongoing activity at the Norwegian Meteorological Institute since the 1970's. The Marine Forecasting Centre provides a 24-hour service for the Norwegian Pollution Control Authority and the oil companies operating in the Norwegian sector. The response time is 30 minutes. From 2002 the service is extended to simulation of oil drift from oil spills in deep water, using the DeepBlow model developed by SINTEF Applied Chemistry. The oil drift model can be applied both for instantaneous and continuous releases. The changes in the mass of oil and emulsion as a result of evaporation and emulsion are computed. For oil spill at deep water, hydrate formation and gas dissolution are taken into account. The properties of the oil depend on the oil type, and in the present version 64 different types of oil can be simulated. For accurate oil drift simulations it is important to have the best possible data on the atmospheric and oceanic conditions. The oil drift simulations at the Norwegian Meteorological Institute are always based on the most updated data from numerical models of the atmosphere and the ocean. The drift of the surface oil is computed from the vectorial sum of the surface current from the ocean model and the wave induced Stokes drift computed from wave energy spectra from the wave prediction model. In the new model the current distribution with depth is taken into account when calculating the drift of the dispersed oil droplets. Salinity and temperature profiles from the ocean model are needed in the DeepBlow model. The result of the oil drift simulations can be plotted on sea charts used for navigation, either as trajectory plots or particle plots showing the situation at a given time. The results can also be sent as data files to be included in the user's own GIS system.

  3. Probabilistic rainfall thresholds for landslide occurrence using a Bayesian approach

    NASA Astrophysics Data System (ADS)

    Berti, M.; Martina, M. L. V.; Franceschini, S.; Pignone, S.; Simoni, A.; Pizziolo, M.

    2012-12-01

    Various methods have been proposed in the literature to predict the rainfall conditions that are likely to trigger landslides in a given area. Most of these methods, however, only consider the rainfall events that resulted in landslides and provide deterministic thresholds with a single possible output (landslide or no-landslide) for a given input (rainfall conditions). Such a deterministic view is not always suited to landslides. Slope stability, in fact, is not ruled by rainfall alone and failure conditions are commonly achieved with a combination of numerous relevant factors. When different outputs (landslide or no-landslide) can be obtained for the same input a probabilistic approach is preferable. In this work we propose a new method for evaluating rainfall thresholds based on Bayesian probability. The method is simple, statistically rigorous, and returns a value of landslide probability (from 0 to 1) for each combination of the selected rainfall variables. The proposed approach was applied to the Emilia-Romagna Region of Italy taking advantage of the historical landslide archive, which includes more than 4000 events for which the date of occurrence is known with daily accuracy. The results show that landsliding in the study area is strongly related to rainfall event parameters (duration, intensity, total rainfall) while antecedent rainfall seems to be less important. The distribution of landslide probability in the rainfall duration-intensity shows an abrupt increase at certain duration-intensity values which indicates a radical change of state of the system and suggests the existence of a real physical threshold.

  4. Landslide mobility and hazards: implications of the 2014 Oso disaster

    USGS Publications Warehouse

    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

    2015-01-01

    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.

  5. Landslide mobility and hazards: implications of the 2014 Oso disaster

    NASA Astrophysics Data System (ADS)

    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.

    2015-02-01

    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.

  6. 3-Dimensional Topographic Models for the Classroom

    NASA Technical Reports Server (NTRS)

    Keller, J. W.; Roark, J. H.; Sakimoto, S. E. H.; Stockman, S.; Frey, H. V.

    2003-01-01

    We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.

  7. 3-dimensional imaging at nanometer resolutions

    DOEpatents

    Werner, James H.; Goodwin, Peter M.; Shreve, Andrew P.

    2010-03-09

    An apparatus and method for enabling precise, 3-dimensional, photoactivation localization microscopy (PALM) using selective, two-photon activation of fluorophores in a single z-slice of a sample in cooperation with time-gated imaging for reducing the background radiation from other image planes to levels suitable for single-molecule detection and spatial location, are described.

  8. Landslide seismic magnitude

    NASA Astrophysics Data System (ADS)

    Lin, C. H.; Jan, J. C.; Pu, H. C.; Tu, Y.; Chen, C. C.; Wu, Y. M.

    2015-11-01

    Landslides have become one of the most deadly natural disasters on earth, not only due to a significant increase in extreme climate change caused by global warming, but also rapid economic development in topographic relief areas. How to detect landslides using a real-time system has become an important question for reducing possible landslide impacts on human society. However, traditional detection of landslides, either through direct surveys in the field or remote sensing images obtained via aircraft or satellites, is highly time consuming. Here we analyze very long period seismic signals (20-50 s) generated by large landslides such as Typhoon Morakot, which passed though Taiwan in August 2009. In addition to successfully locating 109 large landslides, we define landslide seismic magnitude based on an empirical formula: Lm = log ⁡ (A) + 0.55 log ⁡ (Δ) + 2.44, where A is the maximum displacement (μm) recorded at one seismic station and Δ is its distance (km) from the landslide. We conclude that both the location and seismic magnitude of large landslides can be rapidly estimated from broadband seismic networks for both academic and applied purposes, similar to earthquake monitoring. We suggest a real-time algorithm be set up for routine monitoring of landslides in places where they pose a frequent threat.

  9. Landslide in Sirenum

    NASA Technical Reports Server (NTRS)

    2004-01-01

    27 August 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a landslide deposit in a deep trough in Terra Sirenum near 26.1oS, 140.0oW. After the landslide occurred, subsequent erosion of the slope produced talus that covers part of the landslide deposit. This area is about 3 km (1.9 mi) across; sunlight illuminates the scene from the lower left.

  10. Biochemical Applications Of 3-Dimensional Fluorescence Spectrometry

    NASA Astrophysics Data System (ADS)

    Leiner, Marc J.; Wolfbeis, Otto S.

    1988-06-01

    We investigated the 3-dimensional fluorescence of complex mixtures of bioloquids such as human serum, serum ultrafiltrate, human urine, and human plasma low density lipoproteins. The total fluorescence of human serum can be divided into a few peaks. When comparing fluorescence topograms of sera, from normal and cancerous subjects, we found significant differences in tryptophan fluorescence. Although the total fluorescence of human urine can be resolved into 3-5 distinct peaks, some of them. do not result from single fluorescent urinary metabolites, but rather from. several species having similar spectral properties. Human plasma, low density lipoproteins possess a native fluorescence that changes when submitted to in-vitro autoxidation. The 3-dimensional fluorescence demonstrated the presence of 7 fluorophores in the lipid domain, and 6 fluorophores in the protein. dovain- The above results demonstrated that 3-dimensional fluorescence can resolve the spectral properties of complex ,lxtures much better than other methods. Moreover, other parameters than excitation and emission wavelength and intensity (for instance fluorescence lifetime, polarization, or quenchability) may be exploited to give a multidl,ensio,a1 matrix, that is unique for each sample. Consequently, 3-dimensio:Hhal fluorescence as such, or in combination with separation techniques is therefore considered to have the potential of becoming a useful new H.ethod in clinical chemistry and analytical biochemistry.

  11. Landslide Hazards - A National Threat

    USGS Publications Warehouse

    U.S. Geological Survey

    2005-01-01

    Landslides occur and can cause damage in all 50 States. Severe storms, earthquakes, volcanic activity, coastal wave attack, and wildfires can cause widespread slope instability. Landslide danger may be high even as emergency personnel are providing rescue and recovery services. To address landslide hazards, several questions must be considered: Where and when will landslides occur? How big will the landslides be? How fast and how far will they move? What areas will the landslides affect or damage? How frequently do landslides occur in a given area? Answers to these questions are needed to make accurate landslide hazard maps and forecasts of landslide occurrence, and to provide information on how to avoid or mitigate landslide impacts. The U.S. Geological Survey develops methods to answer these questions to help protect U.S. communities from the dangers of landslides.

  12. Reply to comment by Chen et al. on "Controls on the size and geometry of landslides: Insights from discrete element numerical simulations"

    NASA Astrophysics Data System (ADS)

    Aharonov, Einat; Katz, Oded; Morgan, Julia K.; Dugan, Brandon

    2016-01-01

    Chen et al.'s comment presents limit equilibrium (LE) calculations of slope stability, which yield different landslide geometries compared with those obtained by Katz et al. (2014) using the Discrete Element Method (DEM). Previous work, however, has demonstrated excellent agreement in the slide geometries and sizes obtained by DEM vs. those obtained by limit analysis, thereby lending confidence to DEM and to limit analysis as methods to study slope instability and geometry. We suggest three reasons why the LE results may differ from DEM: (1) LE is a static method, which seeks a single failure surface to predict slope stability. Although it captures well the average slope conditions, the details of the stress distribution may be inaccurate. (2) DEM is a dynamic method that holistically simulates the evolution of stress and strain. Thus it is better suited to simulate far from equilibrium situations, such as overly steep slopes with FS < 1, which have strong dynamic responses. (3) The geometries of the slides presented by Chen et al. appear to be constrained by the domain size. We expect that a larger simulation domain may allow exploration of additional slide geometries, potentially with better correspondence with those of the DEM simulations.

  13. Frictional velocity-weakening in landslides on Earth and on other planetary bodies.

    PubMed

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

    2014-01-01

    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. PMID:24595169

  14. Hydroelectric structures studies using 3-dimensional methods

    SciTech Connect

    Harrell, T.R.; Jones, G.V.; Toner, C.K. )

    1989-01-01

    Deterioration and degradation of aged, hydroelectric project structures can significantly affect the operation and safety of a project. In many cases, hydroelectric headworks (in particular) have complicated geometrical configurations, loading patterns and hence, stress conditions. An accurate study of such structures can be performed using 3-dimensional computer models. 3-D computer models can be used for both stability evaluation and for finite element stress analysis. Computer aided engineering processes facilitate the use of 3-D methods in both pre-processing and post-processing of data. Two actual project examples are used to emphasize the authors' points.

  15. Exploring trends of landslide distribution and mechanics of flow with a new database for landslides on Mars

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    by large slumps and avalanches that could result from different properties and mechanisms as well as by the stronger confinement which hamper the flow and thinning of the mass Landslide multiple collapse at the same location could be indicative of predisposing factors, ice water or weak lithologies. At the same time mobility and flow style remain almost unchanged. What controlled the time interval between successive failures? Dynamics of the landslides: We developed a series of numerical simulations to explain the long run-out and the noticeable stretching. Simulations are based on the presence of ice as a lubricating medium either at the base of the landslide, or inside the regolith.

  16. Ganges Chasma Landslide

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 01 April 2002) This image shows a spectacular landslide along a portion of the southern wall of Ganges Chasma within Valles Marineris. Landslides have very characteristic morphologies on Earth, which they also display on Mars. These morphologies include a distinctive escarpment at the uppermost part of the landslide--called a head scarp (seen at the bottom of this image), a down-dropped block of material below that escarpment that dropped almost vertically, and a deposit of debris that moved away from the escarpment at high speed. In this example, the wall rock displayed in the upper part of the cliff is layered, with spurs and chutes created by differing amounts of erosion. Below the steep scarp is a smoother, steep slope of material with small, narrow tongues of debris that have eroded off of the escarpment since the landslide occurred (a talus slope). The actual landslide deposit, visible in the upper half of this image, shows striations that form by differences in the side-by-side motion during high velocity emplacement. This immense landslide traveled some 70 km at speeds that probably exceeded 100 kilometers per hour (60 miles per hour) before coming to rest, forming abrupt, terminal fronts (upper right corner of image). Even at these high speeds, this massive landslide was moving for nearly an hour before it came to rest.

  17. Innovative Techniques for Teaching about Landslides and Triggered Landslide Events

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    When we think of a landslide (mass wasting), both the public and scientists often envisage an individual movement of earth material down a slope. Yet, landslides often occur not as individuals, but as parts of a triggered landslide event. This is where a trigger (e.g., an earthquake or heavy rainfall) results in up to tens of thousands of landslides in a region in the minutes to days after the trigger. In this paper, we will present ideas for innovative demonstrations, teaching practicals and projects, ranging from low-cost low-tech to more advanced digital methods, to communicate the ideas of landslides and triggered landslide events to the public and students. This paper is aimed at those in secondary school/university education and the public sector looking for examples to interest and inform their respective audiences about landslides, triggered landslide events, and the importance and implications of considering landslides not just as individuals, but as populations.

  18. Landslide in Coprates

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows part of a large landslide complex off the north wall of Coprates Chasma in the Valles Marineris trough complex. The wall of Coprates Chasma occupies much of the upper and middle portions of the image; the landslide lobes are on the trough floor in the bottom half of the image. Large boulders the size of houses can be seen on these landslide surfaces. This image is located near 13.9 S, 56.7 W. The picture covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the upper left.

  19. Landslides of Palestinian Region

    NASA Astrophysics Data System (ADS)

    Alwahsh, H.

    2013-12-01

    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

  20. Landslide Hazard Mapping in Rwanda Using Logistic Regression

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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.

  1. Object-based Landslide Mapping: Examples, Challenges and Opportunities

    NASA Astrophysics Data System (ADS)

    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

    2016-04-01

    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

  2. 3-dimensional bioprinting for tissue engineering applications.

    PubMed

    Gu, Bon Kang; Choi, Dong Jin; Park, Sang Jun; Kim, Min Sup; Kang, Chang Mo; Kim, Chun-Ho

    2016-01-01

    The 3-dimensional (3D) printing technologies, referred to as additive manufacturing (AM) or rapid prototyping (RP), have acquired reputation over the past few years for art, architectural modeling, lightweight machines, and tissue engineering applications. Among these applications, tissue engineering field using 3D printing has attracted the attention from many researchers. 3D bioprinting has an advantage in the manufacture of a scaffold for tissue engineering applications, because of rapid-fabrication, high-precision, and customized-production, etc. In this review, we will introduce the principles and the current state of the 3D bioprinting methods. Focusing on some of studies that are being current application for biomedical and tissue engineering fields using printed 3D scaffolds. PMID:27114828

  3. A seismic landslide susceptibility rating of geologic units based on analysis of characterstics of landslides triggered by the 17 January, 1994 Northridge, California earthquake

    USGS Publications Warehouse

    Parise, M.; Jibson, R.W.

    2000-01-01

    One of the most significant effects of the 17 January, 1994 Northridge, California earthquake (M=6.7) was the triggering of thousands of landslides over a broad area. Some of these landslides damaged and destroyed homes and other tructures, blocked roads, disrupted pipelines, and caused other serious damage. Analysis of the distribution and characteristics of these landslides is important in understanding what areas may be susceptible to landsliding in future earthquakes. We analyzed the frequency, distribution, and geometries of triggered landslides in the Santa Susana 7.5??? quadrangle, an area of intense seismic landslide activity near the earthquake epicenter. Landslides occured primarily in young (Late Miocene through Pleistocene) uncemented or very weakly cemented sediment that has been repeatedly folded, faulted, and uplifted in the past 1.5 million years. The most common types of landslide triggered by the earthquake were highly disrupted, shallow falls and slides of rock and debris. Far less numerous were deeper, more coherent slumps and block slides, primarily occuring in more cohesive or competent materials. The landslides in the Santa Susana quadrangle were divided into two samples: single landslides (1502) and landslide complexes (60), which involved multiple coalescing failures of surficial material. We described landslide, morphologies by computing simple morphometric parameters (area, length, width, aspect ratio, slope angle). To quantify and rank the relative susceptibility of each geologic unit to seismic landsliding, we calculated two indices: (1) the susceptibility index, which is the ratio (given as a percentage) of the area covered by landslide sources within a geologic unit to the total outcrop area of that unit: and (2) the frequency index [given in landslides per square kilometer (ls/km2)], which is the total number of landslides within each geologic unit divided by the outcrop area of that unit. Susceptibility categories include very high

  4. Landslides triggered by the earthquake

    SciTech Connect

    Harp, E.L.; Keefer, D.K.

    1990-01-01

    The May 2 earthquake triggered landslides numbering in the thousands. Most numerous were rockfalls and rockslides that occurred mainly on slopes steeper than 60{degree} within sandstone, siltstone, and shale units of Upper Cretaceous and Tertiary strata. Soil falls from cutbank slopes along streams were also numerous. Seven slumps in natural slopes were triggered, and minor liquefaction-induced lateral-spread failures occurred along Los Gatos Creek. Rockfalls and rockslides occurred as far as 34 km northwest, 15 km south, and 26 km southwest of the epicenter. There were few slope failures to the east of the epicenter, owing to the absence of steep slopes in that direction. Throughout the area affected, rockfalls and rockslides were concentrated on southwest-facing slopes; the failures on slopes facing in the southwest quadrant accounted for as much as 93% of all failures in some areas. Rockfalls and rockslides from ridge crests were predominantly from sandstone units. Along steeply incised canyons, however, failures in shale and siltstone units were also common. Small rockslides and soil slides occurred from cut slopes above oil-well pump pads in the oil fields; slumps were common in the outer parts of steep fill slopes of the pump pads. The distribution of seismically induced landslides throughout the entire earthquake-affected area was mapped from true-color airphotos taken on May 3, 1985.

  5. The inner structure of landslides and landslide-prone slopes in south German cuesta landscapes assessed by geophysical, geomorphological and sedimentological approaches

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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

  6. Landslide in Kasei Valles

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) continues in 2003 to return excellent, high resolution images of the red planet's surface. This nearly 1.5 meters (5 ft.) per pixel view of a landslide on a 200 meter-high (219 yards-high) slope in Kasei Valles was specifically targeted for scientific investigation by rotating the MGS spacecraft about 7.8o off-nadir in January 2003. The scar left by the landslide reveals layers in the bedrock at the top the slope and shows a plethora of dark-toned, house-sized boulders that rolled down the slope and collected at the base of the landslide scar. A few meteor impact craters have formed on the landslide deposit and within the scar, indicating that this landslide occurred a very long time ago. Sunlight illuminates this scene from the left/lower left; the landslide is located near 28.3oN, 71.9oW.

  7. Cardiothoracic Applications of 3-dimensional Printing.

    PubMed

    Giannopoulos, Andreas A; Steigner, Michael L; George, Elizabeth; Barile, Maria; Hunsaker, Andetta R; Rybicki, Frank J; Mitsouras, Dimitris

    2016-09-01

    Medical 3-dimensional (3D) printing is emerging as a clinically relevant imaging tool in directing preoperative and intraoperative planning in many surgical specialties and will therefore likely lead to interdisciplinary collaboration between engineers, radiologists, and surgeons. Data from standard imaging modalities such as computed tomography, magnetic resonance imaging, echocardiography, and rotational angiography can be used to fabricate life-sized models of human anatomy and pathology, as well as patient-specific implants and surgical guides. Cardiovascular 3D-printed models can improve diagnosis and allow for advanced preoperative planning. The majority of applications reported involve congenital heart diseases and valvular and great vessels pathologies. Printed models are suitable for planning both surgical and minimally invasive procedures. Added value has been reported toward improving outcomes, minimizing perioperative risk, and developing new procedures such as transcatheter mitral valve replacements. Similarly, thoracic surgeons are using 3D printing to assess invasion of vital structures by tumors and to assist in diagnosis and treatment of upper and lower airway diseases. Anatomic models enable surgeons to assimilate information more quickly than image review, choose the optimal surgical approach, and achieve surgery in a shorter time. Patient-specific 3D-printed implants are beginning to appear and may have significant impact on cosmetic and life-saving procedures in the future. In summary, cardiothoracic 3D printing is rapidly evolving and may be a potential game-changer for surgeons. The imager who is equipped with the tools to apply this new imaging science to cardiothoracic care is thus ideally positioned to innovate in this new emerging imaging modality. PMID:27149367

  8. Landslides - Cause and effect

    USGS Publications Warehouse

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

    1976-01-01

    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.

  9. HYDROGEOLOGY OF THE THERMAL LANDSLIDE

    SciTech Connect

    Vantine, J.

    1985-01-22

    The large Thermal Landslide overlies the initial area of geothermal development at The Geysers. The landslide is waterbearing while the underlying Franciscan formation bedrock units are essentially non-waterbearing except where affected by hydrothermal alteration. Perched ground water moving through the landslide is heated prior to discharge as spring flow.

  10. Regulation of landslide motion by dilatancy and pore pressure feedback

    USGS Publications Warehouse

    Iverson, R.M.

    2005-01-01

    A new mathematical model clarifies how diverse styles and rates of landslide motion can result from regulation of Coulomb friction by dilation or contraction of water-saturated basal shear zones. Normalization of the model equations shows that feedback due to coupling between landslide motion, shear zone volume change, and pore pressure change depends on a single dimensionless parameter ??, which, in turn, depends on the dilatancy angle ?? and the intrinsic timescales for pore pressure generation and dissipation. If shear zone soil contracts during slope failure, then ?? 0, and negative feedback permits slow, steady landslide motion to occur while positive pore pressure is supplied by rain infiltration. Steady state slip velocities v0 obey v0 = -(K/??) p*e, where K is the hydraulic conductivity and p*e is the normalized (dimensionless) negative pore pressure generated by dilation. If rain infiltration and attendant pore pressure growth continue unabated, however, their influence ultimately overwhelms the stabilizing influence of negative p*e. Then, unbounded landslide acceleration occurs, accentuated by an instability that develops if ?? diminishes as landslide motion proceeds. Nonetheless, numerical solutions of the model equations show that slow, nearly steady motion of a clay-rich landslide may persist for many months as a result of negative pore pressure feedback that regulates basal Coulomb friction. Similarly stabilized motion is less likely to occur in sand-rich landslides that are characterized by weaker negative feedback.

  11. Land use change and landslide characteristics analysis for community-based disaster mitigation.

    PubMed

    Chen, Chien-Yuan; Huang, Wen-Lin

    2013-05-01

    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. PMID:22961329

  12. Disseminating Landslide Hazard Information for California Local Government

    NASA Astrophysics Data System (ADS)

    Wills, C. J.

    2010-12-01

    Since 1969, the California Geological Survey has produced numerous maps showing landslide features and delineating potential slope-stability problem areas. These maps have been provided to local governments to encourage consideration of landslide hazards in planning and development decisions. Maps produced from 1986 through 1995 under the Landslide Hazard Mapping Act were advisory only, and their use by local government was never consistent. By contrast, maps of Zones of Required Investigation for seismically induced landslides produced under the Seismic Hazard Zoning Act since 1997 come with detailed guidelines and legal requirements. A legislative act that required landslide hazards be mapped and hazard maps disseminated to local government proved ineffective in landslide hazard mitigation. A later act with requirements that the hazard zone maps be used by local government proved more effective. Planning scenarios have proven to be an effective way of transmitting scientific information about natural hazards to emergency response professionals. Numerous earthquake planning scenarios have been prepared and used as the basis for emergency response exercises. An advantage of scenarios that include loss estimates is that the effects can be put in units of measure that everyone understands, principally deaths and dollars. HAZUS software available from FEMA allows calculation of losses for earthquake scenarios, but similar methods for landslides have not been developed. As part of the USGS Multi-Hazard Demonstration Project, we have estimated the landslide losses for a major west-coast winter storm scenario by developing a system based loosely on HAZUS. Data on landslide damage in past storms has been sparse and inconsistent, but a few data sets are available. The most detailed and complete available data on landslide damage was gathered by the City of Los Angeles following the 1978 storms. We extrapolate from that data to the entire state by first generalizing a

  13. Incorporating 3-dimensional models in online articles

    PubMed Central

    Cevidanes, Lucia H. S.; Ruellasa, Antonio C. O.; Jomier, Julien; Nguyen, Tung; Pieper, Steve; Budin, Francois; Styner, Martin; Paniagua, Beatriz

    2015-01-01

    Introduction The aims of this article were to introduce the capability to view and interact with 3-dimensional (3D) surface models in online publications, and to describe how to prepare surface models for such online 3D visualizations. Methods Three-dimensional image analysis methods include image acquisition, construction of surface models, registration in a common coordinate system, visualization of overlays, and quantification of changes. Cone-beam computed tomography scans were acquired as volumetric images that can be visualized as 3D projected images or used to construct polygonal meshes or surfaces of specific anatomic structures of interest. The anatomic structures of interest in the scans can be labeled with color (3D volumetric label maps), and then the scans are registered in a common coordinate system using a target region as the reference. The registered 3D volumetric label maps can be saved in .obj, .ply, .stl, or .vtk file formats and used for overlays, quantification of differences in each of the 3 planes of space, or color-coded graphic displays of 3D surface distances. Results All registered 3D surface models in this study were saved in .vtk file format and loaded in the Elsevier 3D viewer. In this study, we describe possible ways to visualize the surface models constructed from cone-beam computed tomography images using 2D and 3D figures. The 3D surface models are available in the article’s online version for viewing and downloading using the reader’s software of choice. These 3D graphic displays are represented in the print version as 2D snapshots. Overlays and color-coded distance maps can be displayed using the reader’s software of choice, allowing graphic assessment of the location and direction of changes or morphologic differences relative to the structure of reference. The interpretation of 3D overlays and quantitative color-coded maps requires basic knowledge of 3D image analysis. Conclusions When submitting manuscripts, authors can

  14. Landslide risk assessment

    USGS Publications Warehouse

    Lessing, P.; Messina, C.P.; Fonner, R.F.

    1983-01-01

    Landslide risk can be assessed by evaluating geological conditions associated with past events. A sample of 2,4 16 slides from urban areas in West Virginia, each with 12 associated geological factors, has been analyzed using SAS computer methods. In addition, selected data have been normalized to account for areal distribution of rock formations, soil series, and slope percents. Final calculations yield landslide risk assessments of 1.50=high risk. The simplicity of the method provides for a rapid, initial assessment prior to financial investment. However, it does not replace on-site investigations, nor excuse poor construction. ?? 1983 Springer-Verlag New York Inc.

  15. Small Landslide in Kasei

    NASA Technical Reports Server (NTRS)

    2004-01-01

    21 February 2004 The finger-shaped lobe just right of center in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image is the deposit of a small landslide that came down a dark, layered slope. Landslides are common on Mars in areas of steep topography; this one is located in the Kasei Valles region near 23.9oN, 67.1oW. Sunlight illuminates the scene from the lower left; the picture covers an area 3 km (1.9 mi) wide.

  16. Landslide in Coprates

    NASA Technical Reports Server (NTRS)

    2004-01-01

    15 November 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the distal (far) end of a landslide deposit in Coprates Chasma, part of the vast Valles Marineris trough system. Large boulders, the size of buildings, occur on the landslide surface. This October 2004 picture is located near 15.3oS, 54.6oW, and covers an area approximately 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  17. Landslide in Mutch

    NASA Technical Reports Server (NTRS)

    2005-01-01

    18 November 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the east margin of a landslide off the southern rim of Mutch Crater in the Xanthe Terra region of Mars. This particular landslide was likely triggered by a meteor impact that occurred nearby.

    Location near: 0.7oS, 55.9oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Spring

  18. Landslide in Aureum Chaos

    NASA Technical Reports Server (NTRS)

    2004-01-01

    15 May 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the results of a small landslide off of a hillslope in the Aureum Chaos region of Mars. Mass movement occurred from right (the slope) to left (the lobate feature pointed left). Small dark dots in the landslide area are large boulders. This feature is located near 2.6oS, 24.5oW. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the left/upper left.

  19. Interactive Teaching about Landslides and Triggered Landslide Events

    NASA Astrophysics Data System (ADS)

    Taylor, Faith E.; Malamud, Bruce D.

    2015-04-01

    When we think of a landslide (mass wasting), both the public and scientists often envisage an individual movement of earth material down a slope. Yet, landslides often occur not as individuals, but as parts of a triggered landslide event. This is where a trigger (e.g., an earthquake or heavy rainfall) results in up to tens of thousands of landslides in a region in the minutes to days after the trigger. The sum of the impacts of these landslides may be greater than individual parts. This interactive Prezi poster will present ideas for innovative demonstrations, teaching practicals and projects, ranging from low-cost low-tech to more advanced digital methods, to communicate the ideas of landslides and triggered landslide events to the public and students. We will give live hands-on demonstrations and welcome discussions with other scientists to share ideas and best practices. This paper is aimed at those in secondary school/university education and the public sector looking for examples to interest and inform their respective audiences about landslides, triggered landslide events, and the importance and implications of considering landslides not just as individuals, but as populations.

  20. Landslide risk assessment for individual buildings. A case study from the Prahova Subcarpathians, ROMANIA

    NASA Astrophysics Data System (ADS)

    Armaş, I.

    2012-04-01

    The aim of this study is to quantify the landslide risk for individual buildings using spatial data in a GIS environment. To document the efficiency of the method, a landslide prone area along Prahova Subcarpathian Valley was chosen, where landslide hazard interacts with human settlement and activities. The bivariate landslide susceptibility index (LSI) was used to calculate the spatial probability of landslides occurrence. LSI is a bivariate statistical approach that compares the spatial distribution of landslides with each individual factor that is being considered. The Landslide Susceptibility Index map was produced by numerically adding the weighted thematic maps for slope gradient and aspect, watertable, soil texture, lithology, built environment and land use. The values obtained were in good agreement with the field observations. Validation curves were obtained using the random-split strategy for two combinations of variables: (a) all seven variables and (b) three variables which showed highest individual success rates with respect to landslides occurrences (slope gradient, watertable and land use). The principal pre-disposing factors were found to be slope steepness and groundwater table. Vulnerability was established as the degree of loss to individual buildings resulting from a potential damaging landslide with a given return period in an area. Risk was calculated by multiplying the spatial probability of landslides by the vulnerability for each building and summing up the losses for a 10 years return period.

  1. Landslides and tsunamis

    USGS Publications Warehouse

    Keating, Barbara H., (Edited By); Waythomas, Christopher F.; Dawson, Alastair G.

    2000-01-01

    The study of tsunamis has been shifting away from theoretical modeling of tsunami source, wave propagation and runup toward multidisciplinary investigations, with an emphasis on field studies. This collection of papers highlights the many approaches being utilized to study landslides and tsunamis.

  2. Landslide Caused Damages in a Gallery

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    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.

  3. Supporting response with science: the Oso, Washington, landslide

    NASA Astrophysics Data System (ADS)

    Godt, J.

    2014-12-01

    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

  4. Coprates Chasma Landslide

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    Coprates Chasma comprises the central portion of the Valles Marineris canyon system complex. This image of the southern wall of Coprates Chasma contains a landslide deposit with dunes over portions of slide. Landslides have very characteristic morphologies on Earth, which they also display on Mars. These morphologies include a distinctive escarpment at the uppermost part of the landslide--called a head scarp (seen at the bottom of this image), a down-dropped block of material below that escarpment that dropped almost vertically, and a deposit of debris that moved away from the escarpment at high speed. In this example, the wall rock displayed in the upper part of the cliff contains spurs and chutes created by differing amounts of erosion. The actual landslide deposit is delineated by its fan-shape and lobate margins. The dunes subsequently marched upon the landslide deposit.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a

  5. Landslide volumes and landslide mobilization rates in Umbria, central Italy

    NASA Astrophysics Data System (ADS)

    Guzzetti, Fausto; Ardizzone, Francesca; Cardinali, Mauro; Rossi, Mauro; Valigi, Daniela

    2009-03-01

    A catalogue of 677 landslides of the slide type was selected from a global database of geometrical measurements of individual landslides, including landslide area ( AL) and volume ( VL). The measurements were used to establish an empirical relationship to link AL (in m 2) to VL (in m 3). The relationship takes the form of a power law with a scaling exponent α = 1.450, covers eight orders of magnitude of AL and twelve orders of magnitude of VL, and is in general agreement with existing relationships published in the literature. The reduced scatter of the experiential data around the dependency line, and the fact that the considered landslides occurred in multiple physiographic and climatic environments and were caused by different triggers, indicate that the relationship between VL and AL is largely independent of the physiographical setting. The new relationship was used to determine the volume of individual landslides of the slide type in the Collazzone area, central Italy, a 78.9 km 2 area for which a multi-temporal landslide inventory covering the 69-year period from 1937 to 2005 is available. In the observation period, the total volume of landslide material was VLT = 4.78 × 10 7 m 3, corresponding to an average rate of landslide mobilization φL = 8.8 mm yr - 1 . Exploiting the temporal information in the landslide inventory, the volume of material produced during different periods by new and reactivated landslides was singled out. The wet period from 1937 to 1941 was recognized as an episode of accelerated landslide production. During this 5-year period, approximately 45% of the total landslide material inventoried in the Collazzone area was produced, corresponding to an average rate of landslide mobilization φL = 54 mm yr - 1 , six times higher than the long term rate. The volume of landslide material in an event or period was used as a proxy for the magnitude of the event or period, defined as the logarithm (base 10) of the total landslide volume produced

  6. Tsunamis generated by 3D granular landslides in various scenarios from fjords to conical islands

    NASA Astrophysics Data System (ADS)

    McFall, Brian C.; Fritz, Hermann M.

    2015-04-01

    Landslide generated tsunamis such as in Lituya Bay, Alaska 1958 account for some of the highest recorded tsunami runup heights. 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 pneumatic pistons down slope. Two different landslide materials are used 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 with video image processing. The measured landslide and wave parameters are compared between the planar hill slope used in various scenarios and the convex hill slope of the conical island. The energy conversion rates from the landslide motion to the wave train is quantified for the planar and convex hill slopes. The wave runup data on the opposing headland is analyzed and evaluated with wave theories. The measured landslide and tsunami data serve to validate and advance three-dimensional numerical landslide tsunami prediction models.

  7. Landslides in everyday life: An interdisciplinary approach to understanding vulnerability in the Himalayas

    NASA Astrophysics Data System (ADS)

    Sudmeier-Rieux, K.; Breguet, A.; Dubois, J.; Jaboyedoff, M.

    2009-04-01

    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

  8. Thermal crosstalk in 3-dimensional RRAM crossbar array

    PubMed Central

    Sun, Pengxiao; Lu, Nianduan; Li, Ling; Li, Yingtao; Wang, Hong; Lv, Hangbing; Liu, Qi; Long, Shibing; Liu, Su; Liu, Ming

    2015-01-01

    High density 3-dimensional (3D) crossbar resistive random access memory (RRAM) is one of the major focus of the new age technologies. To compete with the ultra-high density NAND and NOR memories, understanding of reliability mechanisms and scaling potential of 3D RRAM crossbar array is needed. Thermal crosstalk is one of the most critical effects that should be considered in 3D crossbar array application. The Joule heat generated inside the RRAM device will determine the switching behavior itself, and for dense memory arrays, the temperature surrounding may lead to a consequent resistance degradation of neighboring devices. In this work, thermal crosstalk effect and scaling potential under thermal effect in 3D RRAM crossbar array are systematically investigated. It is revealed that the reset process is dominated by transient thermal effect in 3D RRAM array. More importantly, thermal crosstalk phenomena could deteriorate device retention performance and even lead to data storage state failure from LRS (low resistance state) to HRS (high resistance state) of the disturbed RRAM cell. In addition, the resistance state degradation will be more serious with continuously scaling down the feature size. Possible methods for alleviating thermal crosstalk effect while further advancing the scaling potential are also provided and verified by numerical simulation. PMID:26310537

  9. Thermal crosstalk in 3-dimensional RRAM crossbar array.

    PubMed

    Sun, Pengxiao; Lu, Nianduan; Li, Ling; Li, Yingtao; Wang, Hong; Lv, Hangbing; Liu, Qi; Long, Shibing; Liu, Su; Liu, Ming

    2015-01-01

    High density 3-dimensional (3D) crossbar resistive random access memory (RRAM) is one of the major focus of the new age technologies. To compete with the ultra-high density NAND and NOR memories, understanding of reliability mechanisms and scaling potential of 3D RRAM crossbar array is needed. Thermal crosstalk is one of the most critical effects that should be considered in 3D crossbar array application. The Joule heat generated inside the RRAM device will determine the switching behavior itself, and for dense memory arrays, the temperature surrounding may lead to a consequent resistance degradation of neighboring devices. In this work, thermal crosstalk effect and scaling potential under thermal effect in 3D RRAM crossbar array are systematically investigated. It is revealed that the reset process is dominated by transient thermal effect in 3D RRAM array. More importantly, thermal crosstalk phenomena could deteriorate device retention performance and even lead to data storage state failure from LRS (low resistance state) to HRS (high resistance state) of the disturbed RRAM cell. In addition, the resistance state degradation will be more serious with continuously scaling down the feature size. Possible methods for alleviating thermal crosstalk effect while further advancing the scaling potential are also provided and verified by numerical simulation. PMID:26310537

  10. Forensic analysis of Malin landslide in India

    NASA Astrophysics Data System (ADS)

    Ering, P.; Kulkarni, R.; Kolekar, Y.; Dasaka, S. M.; Babu, G. L., Sr.

    2015-09-01

    A devastating landslide occurred on 30th July 2014, resulting in the burial of a village of about 40 houses called Malin, in western India and also led to about 160 deaths. The landslide was triggered by heavy rainfall in the area and mass movement of debris. The paper investigates slope failure in the Malin area using back analysis and numerical methods. Site investigation was conducted to obtain representative information of the area. Finite difference analyses using FLAC 2D is performed for the failed slope to determine the possible cause of failure. Analysis results show that slope failure occurred due to the loss of suction strength at the interface between rock and local soil.

  11. Landsat applied to landslide mapping

    NASA Technical Reports Server (NTRS)

    Sauchyn, D. J.; Trench, N. R.

    1978-01-01

    A variety of features characteristic of rotational landslides may be identified on Landsat imagery. These include tonal mottling, tonal banding, major and secondary scarps, and ponds. Pseudostereoscopic viewing of 9 by 9 in. transparencies was useful for the detailed identification of landslides, whereas 1:250,000 prints enlarged from 70 mm negatives were most suitable for regional analysis. Band 7 is the most useful band for landslide recognition, due to accentuation of ponds and shadows. Examination of both bands 7 and 5, including vegetation information, was found to be most suitable. Although, given optimum terrain conditions, some landslides in Colorado may be recognized, many smaller landslides are not identifiable. Consequently, Landsat is not recommended for detailed regional mapping, or for use in areas similar to Colorado, where alternative (aircraft) imagery is available. However, Landsat may prove useful for preliminary landslide mapping in relatively unknown areas.

  12. Landsliding in partially saturated materials

    USGS Publications Warehouse

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

    2009-01-01

    [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.

  13. A potential submarine landslide tsunami in South China Sea

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Zhang, Y.; Switzer, A. D.

    2010-12-01

    Submarine earthquakes and submarine landslides are two main sources of tsunamis. Tsunami hazard modeling in the South China Sea has been primarily concerned with the potential large submarine earthquakes in the Manila trench. In contrast, evaluating the regional risk posed by tsunamis generated from submarine landslide is a new endeavor. At offshore south central Vietnam, bathymetric and seismic surveys show evidence of potentially tsunamigenic submarine landslides although their ages remain uncertain. We model two hypothetical submarine landslide events at a potential site on the heavily sediment laden, seismically active, steep continental slope offshore southeast Vietnam. Water level rises along the coast of Vietnam are presented for the potential scenarios, which indicate that the southeast coastal areas of Vietnam are at considerable risk of tsunami generated offshore submarine landslides. Key references: Kusnowidjaja Megawati, Felicia Shaw, Kerry Sieh, Zhenhua Huang, Tso-Ren Wu, Y. Lin, Soon Keat Tan and Tso-Chien Pan.(2009). Tsunami hazard from the subduction megathrust of the South China Sea, Part I, Source characterization and the resulting tsunami, Journal of Asian Earth Sciences, Vol. 36(1), pp. 13-20. Enet, F., Grilli, S.T. and Watts, P. (2003). Laboratory experiments for tsunami generated by underwater landslides: comparison with numerical modeling, In: Proceedings of 13th International Conference on Offshore and Polar Engineering, Honolulu, Hawaii, USA, pp. 372-379.

  14. Landslide movement in southwest Colorado triggered by atmospheric tides

    USGS Publications Warehouse

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

    2009-01-01

    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.

  15. Assessing Landslide Mobility Using GIS: Application to Kosrae, Micronesia

    NASA Astrophysics Data System (ADS)

    Reid, M. E.; Brien, D. L.; Godt, J.; Schmitt, R. G.; Harp, E. L.

    2015-12-01

    Deadly landslides are often mobile landslides, as exemplified by the disastrous landslide that occurred near Oso, Washington in 2014 killing 43. Despite this association, many landslide susceptibility maps do not identify runout areas. We developed a simple, GIS-based method for identifying areas potentially overrun by mobile slides and debris flows. Our method links three processes within a DEM landscape: landslide initiation, transport, and debris-flow inundation (from very mobile slides). Given spatially distributed shear strengths, we first identify initiation areas using an infinite-slope stability analysis. We then delineate transport zones, or regions of potential entrainment and/or deposition, using a height/length runout envelope. Finally, where these transport zones intersect the channel network, we start debris-flow inundation zones. The extent of inundation is computed using the USGS model Laharz, modified to include many debris-flow locations throughout a DEM. Potential debris-flow volumes are computed from upslope initiation areas and typical slide thicknesses. We applied this approach to the main island of Kosrae State, Federated States of Micronesia (FSM). In 2002, typhoon Chata'an triggered numerous landslides on the neighboring islands of Chuuk State, FSM, resulting in 43 fatalities. Using an infinite-slope stability model calibrated to the Chuuk event, we identified potential landslide initiation areas on Kosrae. We then delineated potential transport zones using a 20º runout envelope, based on runout observations from Chuuk. Potential debris-flow inundation zones were then determined using Laharz. Field inspections on Kosrae revealed that our resulting susceptibility map correctly classified areas covered by previous debris-flow deposits and did not include areas covered by fluvial deposits. Our map has the advantage of providing a visual tool to portray initiation, transport, and runout zones from mobile landslides.

  16. Tsunamis generated from long, thin, gravitationally accelerated landslides

    NASA Astrophysics Data System (ADS)

    Take, Andy; Mulligan, Ryan; Miller, Garrett

    2016-04-01

    Landslide generated tsunamis are major hazards for developed areas on lakes and reservoirs. Over the past twenty years, enormous advances have been made in both the physical and numerical modeling of the wave generation, wave propagation, and run-up components of this problem by the geoscience community. However, nearly all of the experiments capturing the mechanics of wave generation have been conducted using flume tests of either zero-porosity blocks, or granular material pneumatically accelerated to achieve different impact velocities. Therefore, wave generation has been investigated primarily for physical model landslides that tend to be short, thick, and have a packing that is not entirely dissimilar from the static packing of the material in the release box. In this study we a large-scale landslide flume consisting of an 8.2 m long 30° landslide slope to gravitationally accelerate granular landslides into a 2.1 m wide and 33.0 m long wave flume that terminates with a 27° runup slope, with still water depths of 0.05 to 0.5 m in the reservoir. Granular material is released at the top of the inclined portion of the flume, and is then accelerated under gravity to produce a long, thin, high porosity granular flow prior to impact with the water reservoir. The characteristics of the waves generated under the these conditions are then compared to the results from previous studies on shorter and thicker landslides, before drawing conclusions regarding the applicability of existing empirical models describing the maximum amplitude of landslide generated waves for this class of landslide.

  17. Topographic signatures and a general transport law for deep-seated landslides in a landscape evolution model

    NASA Astrophysics Data System (ADS)

    Booth, Adam M.; Roering, Josh J.; Rempel, Alan W.

    2013-06-01

    A fundamental goal of studying earth surface processes is to disentangle the complex web of interactions among baselevel, tectonics, 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 in weathered bedrock 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 the horizontal landslide flux to the vertical tectonic flux, that characterizes three distinct landscape types. One is dominated by stochastic landsliding, whereby discrete landslide events episodically erode material at rates exceeding the long-term uplift rate. Another is characterized by steady landsliding, in which the landslide flux at any location remains constant through time and is greatest 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, low angle hillslopes despite high uplift rates. The stochastic landsliding regime captures the frequent observation that deep-seated landslides produce large sediment fluxes from small areal extents while being active only a fraction of the time. We suggest that this model is adaptable to a wide range of geologic settings and is useful for interpreting climate-driven changes in landslide behavior.

  18. Landslides in Valles Marineris, Mars

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1979-01-01

    The morphology of the landslides in the Martian equatorial troughs, the geologic structure of the troughs, the time of emplacement, the similarity to terrestrial landslides, and the origin and mechanism of transport are analyzed. About 35 large landslides well-resolved on Viking images were examined, and it is found that the major landslides cover 31,000 sq km of the trough floors, and individual slides range in area from 40 to 7000 sq km. The morphologic variations of the landslides can be attributed mainly to their degree of confinement on trough floors. Many prominent landslides appear to be of similar age and were emplaced after a major faulting that dropped the trough floors. Most sliding occurred after the created scarps were dissected into spurs, gullies, and tributary canyons. Emplacement of the landslides approximately coincided with a late episode of major eruptive activity of the Tharsis volcanoes, and it is suggested that the slides may have originated as gigantic mudflows with slump blocks at their heads. The large size of many landslides is due to the fault scarps as high as 7 km on which they formed in the absence of vigorous fluvial erosion. The landslides suggest that Mars is earthlike in some respects, which may be important for further evaluations.

  19. Prediction of earthquake-triggered landslide event sizes

    NASA Astrophysics Data System (ADS)

    Braun, Anika; Havenith, Hans-Balder; Schlögel, Romy

    2016-04-01

    Seismically induced landslides are a major environmental effect of earthquakes, which may significantly contribute to related losses. Moreover, in paleoseismology landslide event sizes are an important proxy for the estimation of the intensity and magnitude of past earthquakes and thus allowing us to improve seismic hazard assessment over longer terms. Not only earthquake intensity, but also factors such as the fault characteristics, topography, climatic conditions and the geological environment have a major impact on the intensity and spatial distribution of earthquake induced landslides. We present here a review of factors contributing to earthquake triggered slope failures based on an "event-by-event" classification approach. The objective of this analysis is to enable the short-term prediction of earthquake triggered landslide event sizes in terms of numbers and size of the affected area right after an earthquake event occurred. Five main factors, 'Intensity', 'Fault', 'Topographic energy', 'Climatic conditions' and 'Surface geology' were used to establish a relationship to the number and spatial extend of landslides triggered by an earthquake. The relative weight of these factors was extracted from published data for numerous past earthquakes; topographic inputs were checked in Google Earth and through geographic information systems. Based on well-documented recent earthquakes (e.g. Haiti 2010, Wenchuan 2008) and on older events for which reliable extensive information was available (e.g. Northridge 1994, Loma Prieta 1989, Guatemala 1976, Peru 1970) the combination and relative weight of the factors was calibrated. The calibrated factor combination was then applied to more than 20 earthquake events for which landslide distribution characteristics could be cross-checked. One of our main findings is that the 'Fault' factor, which is based on characteristics of the fault, the surface rupture and its location with respect to mountain areas, has the most important

  20. A performance-based approach to landslide risk analysis

    NASA Astrophysics Data System (ADS)

    Romeo, R. W.

    2009-04-01

    severities) and vulnerability (the probability of a limit state performance be reached, given a certain severity). Then, for each landslide all the exposed goods (structures and infrastructures) within the landslide area and within a buffer (representative of the maximum extension of a landslide given a reactivation), are counted. The risk is the product of the damage probability and the ratio of the exposed goods of each landslide to the whole assets exposed to the same type of landslides. Since the risk is computed numerically and by the same procedure applied to all landslides, it is free from any subjective assessment such as those implied in the qualitative methods.

  1. Eos Chasma Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    This VIS image shows several landslides within Eos Chasma. Many very large landslides have occurred within different portions of Valles Marineris. Note where the northern wall has failed in a upside-down bowl shape, releasing the material that formed the landslide deposit.

    Image information: VIS instrument. Latitude -8, Longitude 318.6 East (41.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. Tsunami Generation and Propagation by 3D deformable Landslides and Application to Scenarios

    NASA Astrophysics Data System (ADS)

    McFall, Brian C.; Fritz, Hermann M.

    2014-05-01

    with video image processing. The measured landslide and wave parameters are compared between the planar hill slope used in various scenarios and the convex hill slope of the conical island. The energy conversion rates from the landslide motion to the wave train is quantified for the planar and convex hill slopes. The wave runup data on the opposing headland is analyzed and evaluated with wave theories. A method to predict the maximum wave runup on an opposing headland using nondimensional landslide, water body and bathymetric parameters is derived. The measured landslide and tsunami data serve to validate and advance three-dimensional numerical landslide tsunami prediction models.

  3. Landslide triggering rainfall thresholds estimation using hydrological modelling of catchments in the Ialomita Subcarpathians, Romania

    NASA Astrophysics Data System (ADS)

    Chitu, Zenaida; Busuioc, Aristita; Burcea, Sorin; Sandric, Ionut

    2016-04-01

    This work focuses on the hydro-meteorological analysis for landslide triggering rainfall thresholds estimation in the Ialomita Subcarpathians. This specific area is a complex geological and geomorphic unit in Romania, affected by landslides that produce numerous damages to the infrastructure every few years (1997, 1998, 2005, 2006, 2010, 2012 and 2014). Semi-distributed ModClark hydrological model implemented in HEC HMS software that integrates radar rainfall data, was used to investigate hydrological conditions within the catchment responsible for the occurrence of landslides during the main rainfall events. Statistical analysis of the main hydro-meteorological variables during the landslide events that occurred between 2005 and 2014 was carried out in order to identify preliminary rainfall thresholds for landslides in the Ialomita Subcarpathians. Moreover, according to the environmental catchment characteristics, different hydrological behaviors could be identified based on the spatially distributed rainfall estimates from weather radar data. Two hydrological regimes in the catchments were distinguished: one dominated by direct flow that explains the landslides that occurred due to slope undercutting and one characterized by high soil water storage during prolonged rainfall and therefore where subsurface runoff is significant. The hydrological precipitation-discharge modelling of the catchment in the Ialomita Subcarpathians, in which landslides occurred, helped understanding the landslide triggering and as such can be of added value for landslide research.

  4. Chapter C. The Loma Prieta, California, Earthquake of October 17, 1989 - Landslides

    USGS Publications Warehouse

    Keefer, David K., (Edited By)

    1998-01-01

    Central California, in the vicinity of San Francisco and Monterey Bays, has a history of fatal and damaging landslides, triggered by heavy rainfall, coastal and stream erosion, construction activity, and earthquakes. The great 1906 San Francisco earthquake (MS=8.2-8.3) generated more than 10,000 landslides throughout an area of 32,000 km2; these landslides killed at least 11 people and caused substantial damage to buildings, roads, railroads, and other civil works. Smaller numbers of landslides, which caused more localized damage, have also been reported from at least 20 other earthquakes that have occurred in the San Francisco Bay-Monterey Bay region since 1838. Conditions that make this region particularly susceptible to landslides include steep and rugged topography, weak rock and soil materials, seasonally heavy rainfall, and active seismicity. Given these conditions and history, it was no surprise that the 1989 Loma Prieta earthquake generated thousands of landslides throughout the region. Landslides caused one fatality and damaged at least 200 residences, numerous roads, and many other structures. Direct damage from landslides probably exceeded $30 million; additional, indirect economic losses were caused by long-term landslide blockage of two major highways and by delays in rebuilding brought about by concern over the potential long-term instability of some earthquake-damaged slopes.

  5. A multidimensional stability model for predicting shallow landslide size and shape across landscapes

    PubMed Central

    Milledge, David G; Bellugi, Dino; McKean, Jim A; Densmore, Alexander L; Dietrich, William E

    2014-01-01

    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. PMID:26213663

  6. On the characteristics of landslide tsunamis.

    PubMed

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

    2015-10-28

    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. PMID:26392615

  7. On the characteristics of landslide tsunamis

    PubMed Central

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

    2015-01-01

    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. PMID:26392615

  8. Post failure behaviour of landslide bodies: the large Montescaglioso landslide of 2013 dec

    NASA Astrophysics Data System (ADS)

    Spilotro, Giuseppe; Ermini, Ruggero; Sdao, Francesco; Pellicani, Roberta

    2015-04-01

    After a period of intense rains, on 3 December 2013, already from the day before preceded by several warning signals, a landslide of about 800 m in length, 700 m wide, maximum depth of 40 m, with a total surface area of the first detachment body of 500,000 square meters (50 ha) and volume of about 3 million cubic meters was mobilized from the slopes south of Montescaglioso (MT, Italy). The body was moved towards the south of about 20 m, stopping against the opposite bank of a deep ditch. The distension caused by this movement triggered the movement of additional plates in the upper part of the slope, extending the total surface interested by the instability phenomenon. Despite the extensive damage to houses and commercial buildings, no casualties occurred. The studies and monitoring of sensible parameters, carried out after the landslide movement, revealed numerous specificities prodromal to the landslide phenomenon: a stratigraphic context, even if simple, but disrupted by late-Pleistocene tectonics and by the eustatic deepening of the base level of the hydrography; a widespread aquifer over the entire surface of the landslide body inside the sandy and conglomeratic covering layers; the groundwater flow which revealed the same direction of the landslide displacement; finally, a river network strongly deformed from its natural configuration, with reduced efficiency compared to outflow and increased compared to the process of infiltration. In the distribution of the points of weakness, whose coalescence enveloped the large surface of the landslide, are to be recorded: processes of loss of cementation by sandy and conglomeratic soils; loss of soil matrix operated by groundwater flow in the stretch near the clayey bedrock; interaction of the stiff blue clays with low salinity fluids at the foot of the landslide and elsewhere. The result was a rapid movement of a rigid body, which allowed to recognize a process of progressive failure. The mean shear strength mobilized

  9. Predicting the reactivation of a landslide from precipitation data. The example of a confidential landslide (Switzerland)

    NASA Astrophysics Data System (ADS)

    Franz, Martin; Jaboyedoff, Michel

    2014-05-01

    The return period is widely used to characterise the statistical time between two occurrences of a natural event of a given intensity. It is the case for precipitation, thanks to a long recording time (over 160 years in Switzerland). But for landslides, especially for a single case study, the history is generally insufficient. Thus, the prediction of brusque reactivation of existing slides is still hard to quantify and are crucial information for risk assessment. In this context, the return period of studied landslides can be linked with the one of the precipitation of the same region. The case study, a landslide in an undisclosed location is mainly composed by Würmian deglaciation deposits and intramorainic deposits. It is a partially submerged landslide and contains two water tables. One is associated with the level of the water body and the other is perched. The landslide has a sliding rate of about 2 cm per year and its motion is controlled by the perched water table level and thus, by the precipitations. This study aims to provide a reliable numerical model that permits the estimation of return periods for water-triggered landslides. The model takes into account an infiltration function, the porosity, the permeability, the underground flow and the surface runoff. Inputting the precipitation intensity, it gives the cumulative duration and vice versa. The intersection of these two outputs into an Intensity-Duration-Frequency (IDF) chart lead to a matching return period. As this process is performed for various water table levels, and particularly the one that corresponds to a safety factor smaller than one, the return period of the reactivation of the slide is obtained. In our case study, the parameters of the models are both determined by available data and in situ measurements. Nine different water table levels are investigated and the return period, based on the safety factors calibrated on the worst precipitation scenario, obtained for the sudden

  10. Landslide triggering by rain infiltration

    USGS Publications Warehouse

    Iverson, Richard M.

    2000-01-01

    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 motion and slow, deep

  11. Landslides on Callisto

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Recent Galileo images of the surface of Jupiter's moon Callisto have revealed large landslide deposits within two large impact craters seen in the right side of this image. The two landslides are about 3 to 3.5 kilometers (1.8 to 2.1 miles) in length. They occurred when material from the crater wall failed under the influence of gravity, perhaps aided by seismic disturbances from nearby impacts. These deposits are interesting because they traveled several kilometers from the crater wall in the absence of an atmosphere or other fluids which might have lubricated the flow. This could indicate that the surface material on Callisto is very fine-grained, and perhaps is being 'fluffed' by electrostatic forces which allowed the landslide debris to flow extended distances in the absence of an atmosphere.

    This image was acquired on September 16th, 1997 by the Solid State Imaging (CCD) system on NASA's Galileo spacecraft, during the spacecraft's tenth orbit around Jupiter. North is to the top of the image, with the sun illuminating the scene from the right. The center of this image is located near 25.3 degrees north latitude, 141.3 degrees west longitude. The image, which is 55 kilometers (33 miles) by 44 kilometers (26 miles) across, was acquired at a resolution of 100 meters per picture element.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  12. Video Based Sensor for Tracking 3-Dimensional Targets

    NASA Technical Reports Server (NTRS)

    Howard, R. T.; Book, Michael L.; Bryan, Thomas C.

    2000-01-01

    Video-Based Sensor for Tracking 3-Dimensional Targets The National Aeronautics and Space Administration's (NASAs) Marshall Space Flight Center (MSFC) has been developing and testing video-based sensors for automated spacecraft guidance for several years, and the next generation of video sensor will have tracking rates up to 100 Hz and will be able to track multiple reflectors and targets. The Video Guidance Sensor (VGS) developed over the past several years has performed well in testing and met the objective of being used as the terminal guidance sensor for an automated rendezvous and capture system. The first VGS was successfully tested in closed-loop 3-degree-of-freedom (3- DOF) tests in 1989 and then in 6-DOF open-loop tests in 1992 and closed-loop tests in 1993-4. Development and testing continued, and in 1995 approval was given to test the VGS in an experiment on the Space Shuttle. The VGS flew in 1997 and in 1998, performing well for both flights. During the development and testing before, during, and after the flight experiments, numerous areas for improvement were found. The VGS was developed with a sensor head and an electronics box, connected by cables. The VGS was used in conjunction with a target that had wavelength-filtered retro-reflectors in a specific pattern, The sensor head contained the laser diodes, video camera, and heaters and coolers. The electronics box contained a frame grabber, image processor, the electronics to control the components in the sensor head, the communications electronics, and the power supply. The system works by sequentially firing two different wavelengths of laser diodes at the target and processing the two images. Since the target only reflects one wavelength, it shows up well in one image and not at all in the other. Because the target's dimensions are known, the relative positions and attitudes of the target and the sensor can be computed from the spots reflected from the target. The system was designed to work from I

  13. Shallow Landslide Assessment using SINMAP in Laguna, Philippines

    NASA Astrophysics Data System (ADS)

    Bonus, A. A. B.; Rabonza, M. L.; Alemania, M. K. B.; Alejandrino, I. K.; Ybanez, R. L.; Lagmay, A. M. A.

    2014-12-01

    Due to the tectonic environment and tropical climate in the Philippines, both rain-induced and seismic-induced landslides are common in the country. Numerous hazard mapping activities are regularly conducted by both academic and government institutions using various tools and software. One such software is Stability Index Mapping (SINMAP), a terrain stability mapping tool applied to shallow translational landslide phenomena controlled by shallow groundwater flow convergence. SINMAP modelling combines a slope stability model with a steady-state hydrology model to delineate areas prone to shallow landslides. DOST- Project NOAH, one of the hazard-mapping initiatives of the government, aims to map all landslide hazard in the Philippines using both computer models as well as validating ground data. Laguna, located in the island of Luzon, is one such area where mapping and modelling is conducted. SINMAP modelling of the Laguna area was run with a 5-meter Interferomteric Synthetic Aperture Radar (IFSAR) derived digital terrain model (DTM). Topographic, soil-strength and physical hydrologic parameters, which include cohesion, angle of friction, bulk density and hydraulic conductivity, were assigned to each pixel of a given DTM grid to compute for the corresponding factor of safety. The landslide hazard map generated using SINMAP shows 2% of the total land area is highly susceptible in Santa Mara, Famy, Siniloan, Pangil, Pakil and Los Baἦos Laguna and 10% is moderately susceptible in the eastern parts of Laguna. The data derived from the model is consistent with both ground validation surveys as well as landslide inventories derived from high resolution satellite imagery from 2003 to 2013. With these combined computer and on-the-ground data, it is useful in identifying no-build zone areas and in monitoring activities of the local government units and other agencies concerned. This provides a reasonable delineation of hazard zones for shallow landslide susceptible areas of

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

    NASA Astrophysics Data System (ADS)

    Bednarczyk, Zbigniew

    2014-03-01

    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.

  15. Study of the dynamic behavior of earthflows through the analysis of shear wave velocity in the landslide's body

    NASA Astrophysics Data System (ADS)

    Bertello, Lara

    2015-04-01

    Over the first year of my PhD, I carried out a literature search about earthflows features and dynamics and conducted periodic ReMi-MASW campaigns to assess the temporal variation of shear velocity for several landslides that were recently reactivated. Literature search was conducted to review recent works related to shear wave velocity as an indicator for rheological changes in clay materials (Mainsant et al., 2012). From January to August 2014 I carried out numerous ReMi-MASW surveys to characterize several active earthflows in the Emilia-Romagna Apennines. I did these measures both inside and outside the landslide's bodies, usually during the first ten days after the reactivation. At first, these measures indicate low shear waves velocity inside the landslide and high velocity outside. This is due to the different consistence of the materials, to the different water content and to the void index. Then I repeated the measures over time in the same places on the same landslide, in order to detect the variability of Vs over time in correlations with the landslide's movements. Periodic ReMi-MASW survey were conducted on the following landslides: • The Montevecchio (FC) earthflow was reactivated the 1th of February 2014 (estimated volume of 240.000 m³) and increased the movement's velocity around the 7th of February 2014, after intense precipitations. Analyzing the data collected inside the landslide's body, I observed an increase of Vs over time, due to the decrease of landslide velocity; • The Silla (BO) complex landslide reactivated the 10th of February 2014 (estimated volume of 900.000 m³), and moved downslope with a maximum velocity in the order of several m/hour. Studying the data, it is possible to notice how the Vs increase over time only in the lower portion of the landslide. In fact the upper portion is still active, so the Vs remained unchanged over time. • the Puzzola-Grizzana Morandi (BO) complex landslide. This landslide was reactivated the 10th

  16. Coseismic landslide reactivation characteristics determined from dynamic ring-shear testing

    USGS Publications Warehouse

    Schulz, William H.; Wang, Gonghui; Zhang, Fanyu

    2012-01-01

    Large earthquakes often cause widespread landsliding that alters landscapes and presents significant hazards to human safety and the built environment. For example, the 2008, Mw 7.9 Wenchuan, China earthquake triggered more than 56,000 landslides that killed about 20,000 people. Predicting the occurrence and nature of coseismic landslides remains elusive largely because limitations on laboratory apparatus and a lack of instrumental field observations have precluded understanding the basic response of geologic materials to seismically induced shearing. Coastal Oregon, USA is a region of numerous landslides and great subduction-zone earthquakes that recur every 300-500 yrs, the most recent of which occurred during January 1700. Reactivation of existing landslides during future great earthquakes could threaten human safety because many of these slides potentially impact tsunami evacuation and emergency response routes.

  17. From 2-dimensional cephalograms to 3-dimensional computed tomography scans.

    PubMed

    Halazonetis, Demetrios J

    2005-05-01

    Computed tomography is entering the orthodontic specialty as a mainstream diagnostic modality. Radiation exposure and cost have decreased significantly, and the diagnostic value is very high compared with traditional radiographic options. However, 3-dimensional data present new challenges and need a different approach from traditional viewing of static images to make the most of the available possibilities. Advances in computer hardware and software now enable interactive display of the data on personal computers, with the ability to selectively view soft or hard tissues from any angle. Transfer functions are used to apply transparency and color. Cephalometric measurements can be taken by digitizing points in 3-dimensional coordinates. Application of 3-dimensional data is expected to increase significantly soon and might eventually replace many conventional orthodontic records that are in use today. PMID:15877045

  18. Isidis Crater Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The landslide in this VIS image is located inside an impact crater located south of the Isidis Planitia region of Mars. As with the previous unnamed crater landslide, this one formed due to slope failure of the inner crater rim.

    Image information: VIS instrument. Latitude -2.9, Longitude 90.8 East (269.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Olympus Mons Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The landslide in this VIS image originated from the steep escarpment which surrounds the Olympus Mons volcano on Mars. This landslide is located on the northern side of the volcano.

    Image information: VIS instrument. Latitude 23.2, Longitude 223.9 East (136.1 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. An innovative tool for landslide susceptibility mapping in Kyrgyzstan, Central Asia

    NASA Astrophysics Data System (ADS)

    Saponaro, Annamaria; Pilz, Marco; Wieland, Marc; Bindi, Dino; Parolai, Stefano

    2013-04-01

    Kyrgyzstan is among the most exposed countries in the world to landslide susceptibility. The high seismicity of the area, the presence of high mountain ridges and topographic relieves, the geology of the local materials and the occurrence of heavy precipitations represent the main factors responsible for slope failures. In particular, the large variability of material properties and slope conditions as well as the difficulties in forecasting heavy precipitations locally and in quantifying the level of ground shaking call for harmonized procedures for reducing the negative impact of these factors. Several studies have recently been carried out aiming at preparing landslide susceptibility and hazard maps; however, some of them - qualitative-based - suffer from the application of subjective decision rules from experts in the classification of parameters that influence the occurrence of a landslide. On the other hand, statistical methods provide objectivity over qualitative ones since they allow a numerical evaluation of landslide spatial distribution with landslide potential factors. For this reason, we will make use of a bivariate technique known as Weight-Of-Evidence method to evaluate the influence of landslide predictive factors. The aim of this study is to identify areas in Kyrgyzstan being more prone to earthquake-triggered landslides. An innovative approach which exploits the new advances of GIS technology together with statistical concepts is presented. A range of conditioning factors and their potential impact on landslide activation is quantitatively assessed on the basis of landslide spatial distribution and seismic zonation. Results show areas which are more susceptible to landslides induced by earthquakes. Our approach can be used to fill the gap of subjectivity that typically affects already performed qualitative analysis. The resulting landslide susceptibility map represents a potentially supportive tool for disaster management and planning activities

  1. Landslide hazard mitigation in North America

    USGS Publications Warehouse

    Wieczorek, G.F.; Leahy, P.P.

    2008-01-01

    Active landslides throughout the states and territories of the United States result in extensive property loss and 25-50 deaths per year. The U.S. Geological Survey (USGS) has a long history of detailed examination of landslides since the work of Howe (1909) in the San Juan Mountains of Colorado. In the last four decades, landslide inventory maps and landslide hazard maps have depicted landslides of different ages, identified fresh landslide scarps, and indicated the direction of landslide movement for different regions of the states of Colorado, California, and Pennsylvania. Probability-based methods improve landslide hazards assessments. Rainstorms, earthquakes, wildfires, and volcanic eruptions can trigger landslides. Improvements in remote sensing of rainfall make it possible to issue landslide advisories and warnings for vulnerable areas. From 1986 to 1995, the USGS issued hazard warnings based on rainfall in the San Francisco Bay area. USGS workers also identified rainfall thresholds triggering landslides in Puerto Rico, Hawaii, Washington, and the Blue Ridge Mountains of central Virginia. Detailed onsite monitoring of landslides near highways in California and Colorado aided transportation officials. The USGS developed a comprehensive, multi-sector, and multi-agency strategy to mitigate landslide hazards nationwide. This study formed the foundation of the National Landslide Hazards Mitigation Strategy. The USGS, in partnership with the U.S. National Weather Service and the State of California, began to develop a real-time warning system for landslides from wildfires in Southern California as a pilot study in 2005.

  2. Transformation of dilative and contractive landslide debris into debris flows-An example from marin County, California

    USGS Publications Warehouse

    Fleming, R.W.; Ellen, S.D.; Algus, M.A.

    1989-01-01

    The severe rainstorm of January 3, 4 and 5, 1982, in the San Francisco Bay area, California, produced numerous landslides, many of which transformed into damaging debris flows. The process of transformation was studied in detail at one site where only part of a landslide mobilized into several episodes of debris flow. The focus of our investigation was to learn whether the landslide debris dilated or contracted during the transformation from slide to flow. The landslide debris consisted of sandy colluvium that was separable into three soil horizons that occupied the axis of a small topographic swale. Failure involved the entire thickness of colluvium; however, over parts of the landslide, the soil A-horizon failed separately from the remainder of the colluvium. Undisturbed samples were taken for density measurements from outside the landslide, from the failure zone and overlying material from the part of the landslide that did not mobilize into debris flows, and from the debris-flow deposits. The soil A-horizon was contractive and mobilized to flows in a process analogous to liquefaction of loose, granular soils during earthquakes. The soil B- and C-horizons were dilative and underwent 2 to 5% volumetric expansion during landslide movement that permitted mobilization of debris-flow episodes. Several criteria can be used in the field to differentiate between contractive and dilative behavior including lag time between landsliding and mobilization of flow, episodic mobilization of flows, and partial or complete transformation of the landslide. ?? 1989.

  3. Early warning system to forecast rainfall-induced landslides in Italy (SANF)

    NASA Astrophysics Data System (ADS)

    Rossi, Mauro

    2010-05-01

    Harmful landslide events are frequent in Italy. In this Country, in 2009 rainfall-induced landslides have caused at least 208 casualties, in multiple landslide events. In the period 1950-2009, the average yearly number of harmful landslide events has exceeded 35, most of which rainfall-induced landslide events. These figures indicate the impact that rainfall-induced landslides have on the population of Italy. The Italian national Department for Civil Protection (DPC), an Office of the Prime Minister, and the Research Institute for Geo-Hydrological Protection (IRPI), of the Italian National Research Council (CNR), are designing and implementing a prototype system to forecast the possible occurrence of rainfall-induced landslides in Italy. The system is based on two components. The first component consists of: (i) a set of national, regional, and local rainfall thresholds (of the intensity-duration (ID) type) for possible landslide imitation, (ii) a database of sub-hourly rainfall measurements obtained by a network of 1950 rain gauges in Italy, and (iii) quantitative rainfall forecasts acquired through numerical modelling. Every day, and for each individual rain gauge, the system compares the measured and the forecasted rainfall amounts against pre-defined thresholds, and assigns to each rain gauge a probability for possible landslide occurrence. This information is used to prepare synoptic-scale maps showing where rainfall-induced landslides are expected, in a period of time. The second component of the system consists of synoptic assessments of landslide hazard and risk in Italy, including small-scale zoning maps. The assessments are obtained through statistical modelling of thematic and environmental information, including national catalogues of historical landslides and of historical landslides with human consequences in Italy, in the period 1900-2005. Combination of the hazard and risk zonations with the daily forecasts for possible landslide occurrence, allows

  4. A national early warning system for rainfall-induced landslides in Italy

    NASA Astrophysics Data System (ADS)

    Guzzetti, F.; Rossi, M.; Peruccacci, S.; Brunetti, M.; Marchesini, I.; Ardizzone, F.; Balducci, V.; Bianchi, C.; Cardinali, M.; Fiorucci, F.; Mondini, A.; Reichenbach, P.; Salvati, P.; Tonelli, G.; Dello Buono, D.; Izzi, F.; Amato, L.; La Scaleia, G.; Maio, D.; Pagliara, P.; de Bernardinis, B.

    2010-12-01

    In Italy, intense or prolonged rainfall is the primary cause of landslides, and rainfall-induced slope failures occur every year, claiming lives, causing economic disruption, and producing environmental problems. In 2009, rainfall-induced landslides in Italy have caused more than 200 casualties (deaths, missing persons, injured people), in multiple landslide events. In the period 1950-2009, the average yearly number of harmful landslide events has exceeded 35, most of which were rainfall-induced landslide events. These figures indicate the impact that rainfall-induced landslides have on the population of Italy. The Italian national Department for Civil Protection (DPC), an Office of the Prime Minister, and the Research Institute for Geo-Hydrological Protection (IRPI), of the Italian National Research Council (CNR), have designed and implemented a prototype system to forecast the possible occurrence of rainfall-induced landslides in Italy. The system is based on two main components. The first component consists of: (i) a set of national, regional, and local rainfall thresholds (of the intensity-duration (ID) type) for possible landslide occurrence, (ii) a database of sub-hourly rainfall measurements obtained by a nationwide network of 1950 rain gauges, and (iii) a database of daily quantitative rainfall forecasts obtained through numerical modelling. Every day, and for each individual rain gauge, the system compares the measured and the forecasted rainfall amounts against pre-defined thresholds, and assigns to each rain gauge a probability of possible landslide occurrence. This information is used to prepare synoptic-scale maps showing where rainfall induced landslides are expected, in a period of time. The second component of the system consists of synoptic assessments of landslide hazard and risk in Italy, including small-scale maps. The assessments were obtained through the statistical modelling of thematic and environmental information, including national

  5. Differential Cross Section Kinematics for 3-dimensional Transport Codes

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank

    2008-01-01

    In support of the development of 3-dimensional transport codes, this paper derives the relevant relativistic particle kinematic theory. Formulas are given for invariant, spectral and angular distributions in both the lab (spacecraft) and center of momentum frames, for collisions involving 2, 3 and n - body final states.

  6. Controlled teleportation of a 3-dimensional bipartite quantum state

    NASA Astrophysics Data System (ADS)

    Cao, Hai-Jing; Chen, Zhong-Hua; Song, He-Shan

    2008-07-01

    A controlled teleportation scheme of an unknown 3-dimensional (3D) two-particle quantum state is proposed, where a 3D Bell state and 3D GHZ state function as the quantum channel. This teleportation scheme can be directly generalized to teleport an unknown d-dimensional bipartite quantum state.

  7. Global Flood and Landslide Detection and Prediction Using Satellite Observations

    NASA Astrophysics Data System (ADS)

    Adler, R.; Yilmaz, K.; Hong, Y.; Kirschbaum, D.; Pierce, H.; Policelli, F.

    2009-04-01

    A global flood and landslide detection/prediction system is now running in real-time using satellite multi-satellite rainfall analysis in combination with hydrological models and algorithms to estimate key flood and landslide parameters (http://trmm.gsfc.nasa.gov/publications_dir/potential_flood_hydro.html). The system also uses satellite-based land surface information such as digital elevation information from the NASA SRTM (Shuttle Radar Terrain Mission) and vegetation information from MODIS in he model and algorithm calculations. Progress in using the TRMM Multi-satellite Precipitation Analysis (TMPA) as input to these flood and landslide forecasts is outlined, with case studies as well as validation in terms of flood/landslide events. Examples shown include the major flood in Burma in spring of 2008 and examples of floods and landslide events associated with tropical cyclones. The flood determination algorithm consists of three major components: 1) multi-satellite precipitation estimation; 2) characterization of land surface including digital elevation information and other surface information, topography-derived hydrologic parameters such as flow direction, flow accumulation, basin, and river network etc.; 3) a hydrological model to infiltrate rainfall and route overland runoff. Results of calculated water depth over a threshold are then displayed about six hours after real-time. Time-history of inundations are also calculated and displayed. Validation analysis indicates good results for flood detection and evolution, but with limitations in the current routing calculations. Global numerical weather prediction rainfall forecasts are being used experimentally to extend the period of utility of the flood information. In terms of landslides, the satellite rainfall information is combined with a global landslide susceptibility map, derived from a combination of global surface characteristics (digital elevation topography, slope, soil types, soil texture, and land

  8. Modeling of landslide volume estimation

    NASA Astrophysics Data System (ADS)

    Amirahmadi, Abolghasem; Pourhashemi, Sima; Karami, Mokhtar; Akbari, Elahe

    2016-06-01

    Mass displacement of materials such as landslide is considered among problematic phenomena in Baqi Basin located at southern slopes of Binaloud, Iran; since, it destroys agricultural lands and pastures and also increases deposits at the basin exit. Therefore, it is necessary to identify areas which are sensitive to landslide and estimate the significant volume. In the present study, in order to estimate the volume of landslide, information about depth and area of slides was collected; then, considering regression assumptions, a power regression model was given which was compared with 17 suggested models in various regions in different countries. The results showed that values of estimated mass obtained from the suggested model were consistent with observed data (P value= 0.000 and R = 0.692) and some of the existing relations which implies on efficiency of the suggested model. Also, relations that were created in small-area landslides were more suitable rather than the ones created in large-area landslides for using in Baqi Basin. According to the suggested relation, average depth value of landslides was estimated 3.314 meters in Baqi Basin which was close to the observed value, 4.609 m.

  9. Real-Time Monitoring of Active Landslides

    USGS Publications Warehouse

    Reid, Mark E.; LaHusen, Richard G.; Ellis, William L.

    1999-01-01

    Landslides threaten lives and property in every State in the Nation. To reduce the risk from active landslides, the U.S. Geological Survey (USGS) develops and uses real-time landslide monitoring systems. Monitoring can detect early indications of rapid, catastrophic movement. Up-to-the-minute or real-time monitoring provides immediate notification of landslide activity, potentially saving lives and property. Continuous information from real-time monitoring also provides a better understanding of landslide behavior, enabling engineers to create more effective designs for halting landslide movement.

  10. Frictional weakening of Landslides in the Solar System

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Landslides are an important phenomenon that shapes the surface morphology of solid planetary bodies, including planets and small bodies. In addition, landslide science aims to predict the maximum distance travelled and the maximum velocity reached by a potential landslide in order to quantify the damage it may cause. On the one hand, observations show that the so-called Heim's ratio (i.e. the ratio between the difference of the height of the initial mass and that of the deposit, and the traveling distance) decreases with increasing volume for landslides observed on Earth [1] and other planets like Mars and icy moons like Iapetus [2], but whether this quantity is a good representation of the effective friction during the flow is still a controversial issue. On the other hand, numerical simulations (either continuous or discrete) of real landslides commonly require the assumption of very small friction coefficient to reproduce the extension of deposits [2-5]. We investigate if a common origin can explain the characteristics of landslides in such variety of planetary environments. Based on analytical and numerical solutions for granular flows constrained by remote-sensing observations [3, 7], we developed a consistent method to estimate the effective friction coefficient of landslides, i.e., the constant basal friction coefficient that reproduces their first-order properties. We show that: i) the Heim's ratio is not equivalent to the effective friction coefficient; ii) the friction coefficient decreases with increasing volume or, more fundamentally, with increasing sliding velocity. Inspired by frictional weakening mechanisms thought to operate during earthquakes [8], we propose an empirical velocity-weakening friction law under an unifying phenomenological framework applicable to small to large landslides observed on Earth and beyond (including icy moons of giant planets) whatever the environment and material involved. References: [1] Legros, Eng. Geol. 2002; [2

  11. Submarine landslides in Society and Austral Islands, French Polynesia: Evolution with the age of the edifices

    NASA Astrophysics Data System (ADS)

    Clouard, V.; Bonneville, A.

    2003-04-01

    This paper presents descriptions of numerous submarine landslides in French Polynesia. This inventory shows an evolution of the landslide type with the age of oceanic islands. Submarine active volcanoes are subject to superficial landslides of fragmental material whereas young islands exhibit marks of mass wasting corresponding to giant lateral collapses due to debris avalanche that occurred during the period of volcanic activity. Later, erosional processes generate sand-rubble flows and lead the islands to the stellate morphology known on atolls and guyots. In addition, Tupai atoll and Rurutu Island have been subject to giant slump that deeply modify their shape.

  12. Geological control of earthquake induced landslide in El Salvador

    NASA Astrophysics Data System (ADS)

    Tsige Aga, Meaza

    2010-05-01

    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, (meaza@geo.ucm.es) (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

  13. Risk to housing induced by slow-moving landslides and reactivations in Vaud County (Switzerland)

    NASA Astrophysics Data System (ADS)

    Sonnleitner, M.; Nicolet, P.; Choffet, M.; Jaboyedoff, M.

    2012-04-01

    The Vaud County, which is located in the western part of Switzerland, can be divided in three regions, namely the Jura thrust belt, the Molassic plateau and the Prealps. The County is characterized by numerous landslides, some of which include several houses. A landslide inventory has been made in 1985 based on photointerpretation and actualized in 2008 with aerial LiDAR data. Four classes of depth (shallow, medium, deep and undetermined), four classes of speed (0-2 cm/y, 2-10 cm/y, >10 cm/y and undetermined) and three classes of age (recent, ancient and undetermined) are used to describe the landslides. The 2008 study, which was prepared for a regional hazard map, also added potential landslides in zones contiguous to proven landslides where the local conditions were similar. The first observation that can be made is that the houses built on landslides are most of the time in slow moving landslides (69%, but in 19% of the cases, the speed is unknown), whereas only 0.5% of the houses built on landslides are on fast moving ones. The relation to the depth is less linear, since the proportion of the buildings in deep and medium seated landslides are more or less similar, while only 2% are located on shallow landslides (and 9% on undetermined ones). The location of the landslides regarding zoning has been studied in order to assess the potential development inside sliding areas. The first reassuring result is that 95% of the landslides surface is not classified as building zones (although it doesn't mean that there is no building at all in these areas, since most of the buildings located on landslides are not inside a building zone). However, some of the communities have a large part of their building zones in proven or potential landslides, the maximum being 100% in 8 communities for both categories of landslides and 56% for proven ones. This will lead to problems in land use planning. Another goal is to assess the potential effect of a reactivation or a strong

  14. Design of 3-dimensional complex airplane configurations with specified pressure distribution via optimization

    NASA Technical Reports Server (NTRS)

    Kubrynski, Krzysztof

    1991-01-01

    A subcritical panel method applied to flow analysis and aerodynamic design of complex aircraft configurations is presented. The analysis method is based on linearized, compressible, subsonic flow equations and indirect Dirichlet boundary conditions. Quadratic dipol and linear source distribution on flat panels are applied. In the case of aerodynamic design, the geometry which minimizes differences between design and actual pressure distribution is found iteratively, using numerical optimization technique. Geometry modifications are modeled by surface transpiration concept. Constraints in respect to resulting geometry can be specified. A number of complex 3-dimensional design examples are presented. The software is adopted to personal computers, and as result an unexpected low cost of computations is obtained.

  15. Characterization of Landslide Geometry and Motion near Black Canyon City, Arizona

    NASA Astrophysics Data System (ADS)

    Helmi, H.; Arrowsmith, R.; Marliyani, G. I.

    2015-12-01

    Techniques in the assessment and mitigation of the landslide hazard can be strengthened with application of structure from motion (SfM)-- an inexpensive photogrammetric method. We investigate a landslide north of Black Canyon City, Arizona. The ~0.6 km2 landslide is easily identified through remotely-sensed imagery and in the field. The landslide displaces series of Early and Middle Miocene volcanic and sedimentary rocks. We use SfM to generate a 0.2 m resolution digital elevation model and rectified ortho-mosaic from UAV- and balloon-based images. Derivative maps (hillshade, slope, contour) and the ortho-mosaic were used as base map for our detailed surface geomorphology and geology mapping. The main head scarp is ~600 m long and oriented NE-SW; minor scarps oriented NW-SE are also identified. Numerous open fractures (mm to m lengths) were identified throughout the landslide body (mostly with longitudinal orientation). The occurrence of a distinctive layer of reddish dark colored basalt lava presents a key displaced marker to estimate the landslide movement. Using this marker, the total displacement is estimated to be ~70 m vertically with maximum translation of ~95 m to the SE by both translation and horizontal axis rotation. The landslide geometry, fracture distribution and orientation, all indicate that the landslide is a rotational landslide with its surface movement is largely controlled by local topography. We estimate the rate of the slide motion by measuring the amount of fracture displacement and speculative ages of the disturbed vegetation located along the fractures. The analysis indicates a slow average landslide velocity of about 16 mm/year.

  16. Analysis of landslides triggered in 2010 in Tuzla, Bosnia and Herzegowina

    NASA Astrophysics Data System (ADS)

    Mumic, Edin; Glade, Thomas; Hasel, Stefan

    2013-04-01

    In many countries in the world, landslide information is sparsely available. This is also the case in Tuzla in Bosnia and Herzegowina, although landslides cause regularly significant damage and occur widespread in different catchments. Therefore, this research aims to summarize all available landslide information in the Tuzla region for a sequence of rainstorms in 2010, to analyse the trigger conditions, to investigate the damages and to examine the anthropogenic cause for the landslide initiation. Numerous interviews have been carried out with responsible institutions but also affected population. In addition, the accessible local archives have been investigated. The results show that severe consequences from landslide occurrence on the population are often due to illegal construction of houses. The geological setting and the regolith are clearly predisposing factors, however, the human modifications alter the landslide process significantly. The spatial distribution of landslides and their geophysical properties are analysed and displayed within a GIS. By applying the Intensity-Duration rainfall model it was determined that in the area of the Tuzla landslides, the triggering conditions are reached by 72 hours precipitation conditions with an average intensity of 1.42 mm/h, however, ranging between 0.5 and 20 mm/h in shorter periods. Furthermore, the landslide initiation is clearly highly influenced by anthropogenic factors such as mining, deforestation and slope cutting. These results demonstrate, that a sound and through analysis of landslides in this area, but also throughout Bosnia and Herzegowina would be necessary in order to protect the society from the intense negative consequences.

  17. Landslide risk mapping and modeling in China

    NASA Astrophysics Data System (ADS)

    Li, W.; Hong, Y.

    2015-12-01

    Under circumstances of global climate change, tectonic stress and human effect, landslides are among the most frequent and severely widespread natural hazards on Earth, as demonstrated in the World Atlas of Natural Hazards (McGuire et al., 2004). Every year, landslide activities cause serious economic loss as well as casualties (Róbert et al., 2005). How landslides can be monitored and predicted is an urgent research topic of the international landslide research community. Particularly, there is a lack of high quality and updated landslide risk maps and guidelines that can be employed to better mitigate and prevent landslide disasters in many emerging regions, including China (Hong, 2007). Since the 1950s, landslide events have been recorded in the statistical yearbooks, newspapers, and monographs in China. As disasters have been increasingly concerned by the government and the public, information about landslide events is becoming available from online news reports (Liu et al., 2012).This study presents multi-scale landslide risk mapping and modeling in China. At the national scale, based on historical data and practical experiences, we carry out landslide susceptibility and risk mapping by adopting a statistical approach and pattern recognition methods to construct empirical models. Over the identified landslide hot-spot areas, we further evaluate the slope-stability for each individual site (Sidle and Hirotaka, 2006), with the ultimate goal to set up a space-time multi-scale coupling system of Landslide risk mapping and modeling for landslide hazard monitoring and early warning.

  18. Geoethical Issues in Landslides Hazard Zonation

    NASA Astrophysics Data System (ADS)

    Parkash Gupta, Surya

    2016-04-01

    Landslide hazard zonation is a common geoscientific practice for assessing potential from slope instability problems. Several different approaches and techniques have been applied by various researchers to classify hilly terrains into different degrees or probabilities of landslide hazards. But the study of landslide hazard zonation practices in India reveals that most of these approaches use same factors and approaches for landslide processes. However, the causative and controlling factors for different types of landslides have been found to be different depending on the material (rock, debris or soil) involved in the movement as well as the failure process (fall, topple, slide (rotational, wedge, planar), flow and spread. Each of these landslide process is governed by different factors but during the landslide hazard or susceptibility zonation by many of the geoscientists, same set of factors have been used. Such approaches not only enhance the errors in landslide hazard assessment but also increase the uncertainties in terms of landslide processes. These kind of landslide hazard or susceptibility zonation maps can not be used reliably by the planners, administrators, development agencies, communities and other stakeholders. The approach is likely to affect the credibility of geoscientists among the society. Hence, it is proposed that landslide process specific zonation maps should be generated to classify the hilly terrains into different degrees of hazards. It will also help in establishing responsible factor for each landslide process more accurately and estimating potential landslide hazards with greater reliability.

  19. Physical Modeling of Tsunamis Generated By 3D Deformable Landslides in Various Scenarios From Fjords to Conical Islands

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    compared between the planar hill slope used in various scenarios and the convex hill slope of the conical island. The energy conversion rates from the landslide motion to the wave train is quantified for the planar and convex hill slopes. The wave runup data on the opposing headland is analyzed and evaluated with wave theories. A method to predict the maximum wave runup on an opposing headland using nondimensional landslide, water body and bathymetric parameters is derived. The measured landslide and tsunami data serve to validate and advance three-dimensional numerical landslide tsunami prediction models.

  20. The Corfu Landslide: Analog to Giant Landslides on Mars

    NASA Technical Reports Server (NTRS)

    Lewis, S. W.; Baker, V. R.

    1984-01-01

    In an analog to the great landslides of the Vales Marineris, Mars, a detailed study was made of the Corfu Landslide in south-central Washington. This prehistoric slide is located on the northern flank of the Saddle Mountains, southwest of Othello, Washington. The slide covers a 13 square km area centered on section 11 of T.15N., R.27E., Willamette Meridian, adjacent to the Corfu townsite. Approximately 1 cubic km of material is involved in sliding that was probably initiated by Missoula flooding through the Channeled Scabland. It is concluded that there were four primary factors involved in the initiation of the Corfu landsliding: (1) A slip surface was present at the right orientation; (2) Glacial flooding undercut the slope; (3) Wetter climatic conditions prevailed during that time period; and (4) Some seismic vibrations, known to occur locally, probably acted as a trigger. These factors show that special conditions were required in conjunction to produce landsliding. Studies in progress of the Vales Marieneris suggest that the same factors probably contributed to landsliding there.

  1. The Corfu landslide: Analog to giant landslides on Mars

    NASA Astrophysics Data System (ADS)

    Lewis, S. W.; Baker, V. R.

    1984-04-01

    In an analog to the great landslides of the Vales Marineris, Mars, a detailed study was made of the Corfu Landslide in south-central Washington. This prehistoric slide is located on the northern flank of the Saddle Mountains, southwest of Othello, Washington. The slide covers a 13 square km area centered on section 11 of T.15N., R.27E., Willamette Meridian, adjacent to the Corfu townsite. Approximately 1 cubic km of material is involved in sliding that was probably initiated by Missoula flooding through the Channeled Scabland. It is concluded that there were four primary factors involved in the initiation of the Corfu landsliding: (1) A slip surface was present at the right orientation; (2) Glacial flooding undercut the slope; (3) Wetter climatic conditions prevailed during that time period; and (4) Some seismic vibrations, known to occur locally, probably acted as a trigger. These factors show that special conditions were required in conjunction to produce landsliding. Studies in progress of the Vales Marieneris suggest that the same factors probably contributed to landsliding there.

  2. Multimodality 3-Dimensional Image Integration for Congenital Cardiac Catheterization

    PubMed Central

    2014-01-01

    Cardiac catheterization procedures for patients with congenital and structural heart disease are becoming more complex. New imaging strategies involving integration of 3-dimensional images from rotational angiography, magnetic resonance imaging (MRI), computerized tomography (CT), and transesophageal echocardiography (TEE) are employed to facilitate these procedures. We discuss the current use of these new 3D imaging technologies and their advantages and challenges when used to guide complex diagnostic and interventional catheterization procedures in patients with congenital heart disease. PMID:25114757

  3. Mapping landslide source and transport areas in VHR images with Object-Based Analysis and Support Vector Machines

    NASA Astrophysics Data System (ADS)

    Heleno, Sandra; Matias, Magda; Pina, Pedro

    2015-04-01

    Visual interpretation of satellite imagery remains extremely demanding in terms of resources and time, especially when dealing with numerous multi-scale landslides affecting wide areas, such as is the case of rainfall-induced shallow landslides. Applying automated methods can contribute to more efficient landslide mapping and updating of existing inventories, and in recent years the number and variety of approaches is rapidly increasing. Very High Resolution (VHR) images, acquired by space-borne sensors with sub-metric precision, such as Ikonos, Quickbird, Geoeye and Worldview, are increasingly being considered as the best option for landslide mapping, but these new levels of spatial detail also present new challenges to state of the art image analysis tools, asking for automated methods specifically suited to map landslide events on VHR optical images. In this work we develop and test a methodology for semi-automatic landslide recognition and mapping of landslide source and transport areas. The method combines object-based image analysis and a Support Vector Machine supervised learning algorithm, and was tested using a GeoEye-1 multispectral image, sensed 3 days after a damaging landslide event in Madeira Island, together with a pre-event LiDAR DEM. Our approach has proved successful in the recognition of landslides on a 15 Km2-wide study area, with 81 out of 85 landslides detected in its validation regions. The classifier also showed reasonable performance (false positive rate 60% and false positive rate below 36% in both validation regions) in the internal mapping of landslide source and transport areas, in particular in the sunnier east-facing slopes. In the less illuminated areas the classifier is still able to accurately map the source areas, but performs poorly in the mapping of landslide transport areas.

  4. The effect of complex fault rupture on the distribution of landslides triggered by the 12 January 2010, Haiti earthquake

    USGS Publications Warehouse

    Harp, Edwin L.; Jibson, Randall W.; Dart, Richard L.

    2013-01-01

    The MW 7.0, 12 January 2010, Haiti earthquake triggered more than 7,000 landslides in the mountainous terrain south of Port-au-Prince over an area that extends approximately 50 km to the east and west from the epicenter and to the southern coast. Most of the triggered landslides were rock and soil slides from 25°–65° slopes within heavily fractured limestone and deeply weathered basalt and basaltic breccia. Landslide volumes ranged from tens of cubic meters to several thousand cubic meters. Rock slides in limestone typically were 2–5 m thick; slides within soils and weathered basalt typically were less than 1 m thick. Twenty to thirty larger landslides having volumes greater than 10,000 m3 were triggered by the earthquake; these included block slides and rotational slumps in limestone bedrock. Only a few landslides larger than 5,000 m3 occurred in the weathered basalt. The distribution of landslides is asymmetric with respect to the fault source and epicenter. Relatively few landslides were triggered north of the fault source on the hanging wall. The densest landslide concentrations lie south of the fault source and the Enriquillo-Plantain-Garden fault zone on the footwall. Numerous landslides also occurred along the south coast west of Jacmél. This asymmetric distribution of landsliding with respect to the fault source is unusual given the modeled displacement of the fault source as mainly thrust motion to the south on a plane dipping to the north at approximately 55°; landslide concentrations in other documented thrust earthquakes generally have been greatest on the hanging wall. This apparent inconsistency of the landslide distribution with respect to the fault model remains poorly understood given the lack of any strong-motion instruments within Haiti during the earthquake.

  5. Quantify landslide exposure in areas with limited hazard information

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    probability of landslides, on the basis of the expert knowledge on the landslide phenomena. For each of twenty-five municipalities included in the study area, the expected losses (or consequences), in monetary terms, due to different hazard scenarios have been evaluated. After calculating the economic losses, the total risk at municipal level was evaluated, by generating the risk curves and calculating the area under the curves. The analysis of the risk curves related to the 25 municipalities has showed that the total risk values, expressed in monetary terms, is higher for the bigger municipal areas located in the southern part of the study area where the elevation is lower, as are more numerous the elements at risk distributed on the municipal territory. Finally, this quantitative risk assessment procedure, which calculates the exposure in monetary terms of elements at risk, allows to establish the changes in risk in future with urban development and monetary inflation.

  6. Landslides triggered by the 1946 Ancash earthquake, Peru

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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

  7. Channel Wall Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation.

    Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  8. Terra Cimmeria Crater Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The landslide in this VIS image is located inside an impact crater in the Terra Cimmeria region of Mars. The unnamed crater hosting this image is just east of Molesworth Crater.

    Image information: VIS instrument. Latitude -27.7, Longitude 152 East (208 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. Melas Chasma Landslide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03041 Dunes in Darwin Crater

    The landslide in the center of this image occurred in the Melas Chasma region of Valles Marineris.

    Image information: VIS instrument. Latitude 11S, Longitude 292.6E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  10. Landslide in a Crater

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The landslide in this VIS image is located inside an impact crater in the Elysium region of Mars. The unnamed crater is located at the margin of the volcanic flows from the Elysium Mons complex.

    Image information: VIS instrument. Latitude 1.2, Longitude 134 East (226 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. Landslide susceptibility mapping using GIS-based statistical models and Remote sensing data in tropical environment

    PubMed Central

    Hashim, Mazlan

    2015-01-01

    This research presents the results of the GIS-based statistical models for generation of landslide susceptibility mapping using geographic information system (GIS) and remote-sensing data for Cameron Highlands area in Malaysia. Ten factors including slope, aspect, soil, lithology, NDVI, land cover, distance to drainage, precipitation, distance to fault, and distance to road were extracted from SAR data, SPOT 5 and WorldView-1 images. The relationships between the detected landslide locations and these ten related factors were identified by using GIS-based statistical models including analytical hierarchy process (AHP), weighted linear combination (WLC) and spatial multi-criteria evaluation (SMCE) models. The landslide inventory map which has a total of 92 landslide locations was created based on numerous resources such as digital aerial photographs, AIRSAR data, WorldView-1 images, and field surveys. Then, 80% of the landslide inventory was used for training the statistical models and the remaining 20% was used for validation purpose. The validation results using the Relative landslide density index (R-index) and Receiver operating characteristic (ROC) demonstrated that the SMCE model (accuracy is 96%) is better in prediction than AHP (accuracy is 91%) and WLC (accuracy is 89%) models. These landslide susceptibility maps would be useful for hazard mitigation purpose and regional planning. PMID:25898919

  12. Dynamic simulation of landslide based on thermo-poro-elastic approach

    NASA Astrophysics Data System (ADS)

    He, Si-Ming; Liu, Wei; Wang, Juan

    2015-02-01

    Catastrophic landslides often extend for surprisingly long distances, a trend consolidated by a decrease in the apparent friction coefficient with an increasing landslide volume. However, there is not yet a physical model able to predict the long distances traveled by landslides in the condition of deformation. A two-dimensional model for simulating catastrophic landslide motion is presented in this paper and is based on a lump model for thermo-poro-elastic mediums. The model can concurrently simulate landslide dynamic processes, and pore pressure and frictional heating evolution in the shear zone at the bottom of a landslide. These are based upon the shallow-seated groundwater table assumption and depth-averaged integration, as well as the thermo-poro-elastic approach. A combined computational method based on the finite volume method and Crank-Nicolson method is proposed to solve the coupled equations. Four computational experiments have been run and the numerical results indicate that frictional heating enhances pore water pressure and reduces the friction, resulting in higher mobility and longer distances traveled. The value of pore water pressure can also influence the deformation process of a landslide.

  13. Landslide susceptibility mapping using GIS-based statistical models and Remote sensing data in tropical environment.

    PubMed

    Shahabi, Himan; Hashim, Mazlan

    2015-01-01

    This research presents the results of the GIS-based statistical models for generation of landslide susceptibility mapping using geographic information system (GIS) and remote-sensing data for Cameron Highlands area in Malaysia. Ten factors including slope, aspect, soil, lithology, NDVI, land cover, distance to drainage, precipitation, distance to fault, and distance to road were extracted from SAR data, SPOT 5 and WorldView-1 images. The relationships between the detected landslide locations and these ten related factors were identified by using GIS-based statistical models including analytical hierarchy process (AHP), weighted linear combination (WLC) and spatial multi-criteria evaluation (SMCE) models. The landslide inventory map which has a total of 92 landslide locations was created based on numerous resources such as digital aerial photographs, AIRSAR data, WorldView-1 images, and field surveys. Then, 80% of the landslide inventory was used for training the statistical models and the remaining 20% was used for validation purpose. The validation results using the Relative landslide density index (R-index) and Receiver operating characteristic (ROC) demonstrated that the SMCE model (accuracy is 96%) is better in prediction than AHP (accuracy is 91%) and WLC (accuracy is 89%) models. These landslide susceptibility maps would be useful for hazard mitigation purpose and regional planning. PMID:25898919

  14. Major risk from rapid, large-volume landslides in Europe (EU Project RUNOUT)

    NASA Astrophysics Data System (ADS)

    Kilburn, Christopher R. J.; Pasuto, Alessandro

    2003-08-01

    Project RUNOUT has investigated methods for reducing the risk from large-volume landslides in Europe, especially those involving rapid rates of emplacement. Using field data from five test sites (Bad Goisern and Köfels in Austria, Tessina and Vajont in Italy, and the Barranco de Tirajana in Gran Canaria, Spain), the studies have developed (1) techniques for applying geomorphological investigations and optical remote sensing to map landslides and their evolution; (2) analytical, numerical, and cellular automata models for the emplacement of sturzstroms and debris flows; (3) a brittle-failure model for forecasting catastrophic slope failure; (4) new strategies for integrating large-area Global Positioning System (GPS) arrays with local geodetic monitoring networks; (5) methods for raising public awareness of landslide hazards; and (6) Geographic Information System (GIS)-based databases for the test areas. The results highlight the importance of multidisciplinary studies of landslide hazards, combining subjects as diverse as geology and geomorphology, remote sensing, geodesy, fluid dynamics, and social profiling. They have also identified key goals for an improved understanding of the physical processes that govern landslide collapse and runout, as well as for designing strategies for raising public awareness of landslide hazards and for implementing appropriate land management policies for reducing landslide risk.

  15. What Were the Reasons for the Rapid Landslide Occurrence in "Piaseczno" Open Pit? - Analysis of the Landslide Process

    NASA Astrophysics Data System (ADS)

    Jakóbczyk, Joanna; Cała, Marek; Stopkowicz, Agnieszka

    2015-03-01

    Landslides are major natural hazards occurring in opencast mining. The problem of slope stability failure in the existing open pit mines as well as in those which are at a stage of technical closure is current issue in Poland and all over the world. This problem requires conducting in-depth and meaningful analysis which will identify the causes of processes characterized by a very rapid course and large extent. The paper presents the analysis of the landslide causes, which took place on May 11, 2011 on the western slope of the internal dump in "Piaseczno" sulphur mine (at a stage of technical closure). It was the first native sulphur open pit mine in Poland in which the exploitation was carried out from 1958 untill 1971. Reclamation works have been ongoing since 2005. The aim of these works is to create water body which will be used for recreational purposes. During the reclamation works on the western slope of "Piaseczno" reservoir the landslide processes were activated. A detailed description of geology and preliminary analyses of landslide processes are given in [1]. The development of landslide took place in a very violent manner. Moreover, the occurrence of the landslide caused the movement of the reservoir shoreline by about 350 meters and created a bay with the area of approximately 6 hectares. Displacement of 600 000 m3 of soil masses under the water resulted in its level rising by 56 cm. The total volume of ground masses was over 1 million m3. The analysis of the landslide process activation was carried out for two representative cross-sections of the internal dump. Numerical calculations were performed using the Limit Equilibrium Method (SLOPE/W GeoStudio) and the Finite Difference Method using the Shear Strength Reduction Method (FLAC Slope). They were aimed at determining the shape and extent of potential slip surface, which would correspond to the observed landslide. The purpose of the analysis, the results of which are presented in the article, was to

  16. Analysis of post-earthquake landslide activity and geo-environmental effects

    NASA Astrophysics Data System (ADS)

    Tang, Chenxiao; van Westen, Cees; Jetten, Victor

    2014-05-01

    Large earthquakes can cause huge losses to human society, due to ground shaking, fault rupture and due to the high density of co-seismic landslides that can be triggered in mountainous areas. In areas that have been affected by such large earthquakes, the threat of landslides continues also after the earthquake, as the co-seismic landslides may be reactivated by high intensity rainfall events. Earthquakes create Huge amount of landslide materials remain on the slopes, leading to a high frequency of landslides and debris flows after earthquakes which threaten lives and create great difficulties in post-seismic reconstruction in the earthquake-hit regions. Without critical information such as the frequency and magnitude of landslides after a major earthquake, reconstruction planning and hazard mitigation works appear to be difficult. The area hit by Mw 7.9 Wenchuan earthquake in 2008, Sichuan province, China, shows some typical examples of bad reconstruction planning due to lack of information: huge debris flows destroyed several re-constructed settlements. This research aim to analyze the decay in post-seismic landslide activity in areas that have been hit by a major earthquake. The areas hit by the 2008 Wenchuan earthquake will be taken a study area. The study will analyze the factors that control post-earthquake landslide activity through the quantification of the landslide volume changes well as through numerical simulation of their initiation process, to obtain a better understanding of the potential threat of post-earthquake landslide as a basis for mitigation planning. The research will make use of high-resolution stereo satellite images, UAV and Terrestrial Laser Scanning(TLS) to obtain multi-temporal DEM to monitor the change of loose sediments and post-seismic landslide activities. A debris flow initiation model that incorporates the volume of source materials, vegetation re-growth, and intensity-duration of the triggering precipitation, and that evaluates

  17. Digital inventory of landslides and related deposits in Honduras triggered by Hurricane Mitch

    USGS Publications Warehouse

    Harp, Edwin L.; Hagaman, Kirk W.; Held, Matthew D.; McKenna, Jonathan P.

    2002-01-01

    Intense rainfall from Hurricane Mitch from October 27-31, 1998, exceeded 900 mm in places in Honduras and triggered in excess of 500,000 landslides throughout the country. Landslides damaged an estimated 70% of the road network in Honduras based on estimates by the U. S Army Corps of Engineers. Numbers of fatalities due to landslides are not accurately known due to the fact that numerous small villages throughout Honduras lost residents to landslides without an official count being recorded. A conservative estimate would place the number at near 1,000. Debris flows accounted for over 95% of the landslides and ranged in thickness from 1 to 15 m. Flow path lengths of these failures ranged from several meters to 7.5 km. The highest concentrations of debris flows occurred in the mountains near the town of Choluteca where over 900 mm of rain fell in three days. Although landslides other than debris flows were few, several deep-seated landslides in the city of Tegucigalpa severely impacted people and property. The 'El Berrinche' rotational slump/earth flow of approximately six million cubic meters volume destroyed the entire neighborhood of Colonia Soto near the center of the city. The landslide also dammed the Rio Choluteca and created a lagoon behind the landslide dam, which immediately posed a health problem for the city, because raw, untreated sewage was emptying into the Rio Choluteca. Several areas of highly concentrated landslides have been responsible for much of the flooding problem as well. Huge sediment influxes from landslide source areas near La Ceiba, La Libertad, Marale, and in several arms of El Cajon Reservoir have reduced stream capacities to practically nothing and have exacerbated flooding conditions in even the moderate rainfall seasons since Hurricane Mitch. The ongoing hazard to communities from landslides triggered during Hurricane Mitch are being analyzed using aerial photography taken by the U.S. Air Force and by supplemental photography taken

  18. Landslide Hazard Probability Derived from Inherent and Dynamic Determinants

    NASA Astrophysics Data System (ADS)

    Strauch, Ronda; Istanbulluoglu, Erkan

    2016-04-01

    Landslide hazard research has typically been conducted independently from hydroclimate research. We unify these two lines of research to provide regional scale landslide hazard information for risk assessments and resource management decision-making. Our approach combines an empirical inherent landslide probability with a numerical dynamic probability, generated by combining routed recharge from the Variable Infiltration Capacity (VIC) macro-scale land surface hydrologic model with a finer resolution probabilistic slope stability model run in a Monte Carlo simulation. Landslide hazard mapping is advanced by adjusting the dynamic model of stability with an empirically-based scalar representing the inherent stability of the landscape, creating a probabilistic quantitative measure of geohazard prediction at a 30-m resolution. Climatology, soil, and topography control the dynamic nature of hillslope stability and the empirical information further improves the discriminating ability of the integrated model. This work will aid resource management decision-making in current and future landscape and climatic conditions. The approach is applied as a case study in North Cascade National Park Complex, a rugged terrain with nearly 2,700 m (9,000 ft) of vertical relief, covering 2757 sq km (1064 sq mi) in northern Washington State, U.S.A.

  19. Landslide caracteristics determination using bayesian inversion and seismic recording

    NASA Astrophysics Data System (ADS)

    Mangeney, A.; Moretti, L.; Capdeville, Y.; Stutzmann, E.; Bodin, T.; Bouchut, F.

    2014-12-01

    Gravitational instabilities, such as landslides, avalanches, or debris flows, play a key role in erosional processes and represent one of the major natural hazards in mountainous, coastal, and volcanic regions. Despite the great amount of field, experimental and numerical work devoted to this problem, the understanding of the physical processes at work in gravitational flows is still an open issue, in particular due to the lack of observations relevant to their dynamics. In this context, the seismic signal generated by gravitational flows is a unique opportunity to obtain information on their dynamics and characteristics. Here we present the study of the 1997 Boxing Day landslide that occurred in Montserrat. We accessed the force applied by the landslide to the ground surface responsible of the seismic waves by inverting the seismic waveform recorded (force-time function). This force was then used as a constraint in a bayesian inversion problem where the forward problem is the force-time function calculation obtained by simulating the landslide with the SHALTOP model (mangeney et al., 2007). With this method, we are able to give an estimate of the rheology (friction coefficient) and the initial shape of the collapsing mass. The volume retrieved is very similar to that obtained by field observations. The friction coefficient determined is also similar to that constrained by former studies or to that predicted by empirical laws (Lucas et al., 2014). Furthermore the method permits to give an estimate of the error made on these parameters.

  20. Communicating landslide hazard and risk through global catalogs and a forecasting framework

    NASA Astrophysics Data System (ADS)

    Kirschbaum, D. B.; Adler, D.; Adler, R. F.

    2010-12-01

    over estimation of potential landslide activity areas, are geographically variable and depend on the spatial resolution of the landslide susceptibility information as well as the rainfall information and thresholds used to identify triggering conditions in time. The ability to accurately evaluate the algorithm’s performance is closely linked to the availability and accuracy of landslide event information in the global landslide catalog. Near real-time communication of susceptible landslide areas from the landslide algorithm framework is controlled by the availability and accuracy of satellite-based precipitation information. Current missions such as the Tropical Rainfall Measuring Mission (TRMM) as well as future missions such as the Global Precipitation Measurement (GPM) mission provide critical inputs to near real-time hazard assessment and numerical weather forecasts. Synthesizing landslide report information and the landslide hazard forecasting framework provides the unique opportunity to evaluate and communicate landslide hazard and risk globally to a broad audience, including the scientific community, public, governments, and response organizations.

  1. Real-time monitoring of landslides

    USGS Publications Warehouse

    Reid, Mark E.; LaHusen, Richard G.; Baum, Rex L.; Kean, Jason W.; Schulz, William H.; Highland, Lynn M.

    2012-01-01

    Landslides cause fatalities and property damage throughout the Nation. To reduce the impact from hazardous landslides, the U.S. Geological Survey develops and uses real-time and near-real-time landslide monitoring systems. Monitoring can detect when hillslopes are primed for sliding and can provide early indications of rapid, catastrophic movement. Continuous information from up-to-the-minute or real-time monitoring provides prompt notification of landslide activity, advances our understanding of landslide behavior, and enables more effective engineering and planning efforts.

  2. Landslide Hazard in Georgia

    NASA Astrophysics Data System (ADS)

    Gaprindashvili, George; Tsereteli, Emil; Gaprindashvili, Merab

    2014-05-01

    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

  3. Landslide Hazard in Georgia

    NASA Astrophysics Data System (ADS)

    Gaprindashvili, G.; Tsereteli, E.; Gaprindashvili, M.

    2013-12-01

    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

  4. The 3-dimensional cellular automata for HIV infection

    NASA Astrophysics Data System (ADS)

    Mo, Youbin; Ren, Bin; Yang, Wencao; Shuai, Jianwei

    2014-04-01

    The HIV infection dynamics is discussed in detail with a 3-dimensional cellular automata model in this paper. The model can reproduce the three-phase development, i.e., the acute period, the asymptotic period and the AIDS period, observed in the HIV-infected patients in a clinic. We show that the 3D HIV model performs a better robustness on the model parameters than the 2D cellular automata. Furthermore, we reveal that the occurrence of a perpetual source to successively generate infectious waves to spread to the whole system drives the model from the asymptotic state to the AIDS state.

  5. The relationship between extreme precipitation events and landslides distributions in 2009 in Lower Austria

    NASA Astrophysics Data System (ADS)

    Katzensteiner, H.; Bell, R.; Petschko, H.; Glade, T.

    2012-04-01

    The prediction and forecast of widespread landsliding for a given triggering event is an open research question. Numerous studies tried to link spatial rainfall and landslide distributions. This study focuses on analysing the relationship between intensive precipitation and rainfall-triggered shallow landslides in the year 2009 in Lower Austria. Landslide distributions were gained from the building ground register, which is maintained by the Geological Survey of Lower Austria. It contains detailed information of landslides, which were registered due to damage reports. Spatially distributed rainfall estimates were extracted from INCA (Integrated Nowcasting through Comprehensive Analysis) precipitation analysis, which is a combination of station data interpolation and radar data in a spatial resolution of 1km developed by the Central Institute for Meteorology and Geodynamics (ZAMG), Vienna, Austria. The importance of the data source is shown by comparing rainfall data based on reference gauges, spatial interpolation and INCA-analysis for a certain storm period. INCA precipitation data can detect precipitating cells that do not hit a station but might trigger a landslide, which is an advantage over the application of reference stations for the definition of rainfall thresholds. Empirical thresholds at regional scale were determined based on rainfall-intensity and duration in the year 2009 and landslide information. These thresholds are dependent on the criteria which separate the landslide triggering and non-triggering precipitation events from each other. Different approaches for defining thresholds alter the shape of the threshold as well. A temporarily threshold I=8,8263*D^(-0.672) for extreme rainfall events in summer in Lower Austria was defined. A verification of the threshold with similar events of other years as well as following analyses based on a larger landslide database are in progress.

  6. Geology and tsunamigenic potential of submarine landslides in Santa Barbara Channel, Southern California

    USGS Publications Warehouse

    Fisher, M.A.; Normark, W.R.; Greene, H. Gary; Lee, H.J.; Sliter, R.W.

    2005-01-01

    A large submarine landslide complex and four small landslides developed under the Santa Barbara Channel, suggesting a potential hazard from landslide-generated tsunamis. We integrate offshore stratigraphy and geologic structure, multibeam bathymetric information, and several kinds of seismic-reflection data to understand how and when the submarine landslides formed. Seismic-reflection data show that mass failure along the slope began at least 200 ka ago. Landslides appear as zones of poor reflectivity having an irregular upper surface, and these zones alternate vertically with strong parallel reflections. The emplacement ages of two of the three main landslide lobes are well established at 8 and 10 ka. The source material for the youngest part of the landslide complex was sediment of probable late Pleistocene and Holocene age that accumulated in a shelf-edge delta. Directly under this delta, growth of faults and anticlines was particularly intense and tended to oversteepen the deltaic deposits. These active structures also formed migration pathways and reservoirs for aqueous and hydrocarbon fluids from the deep basin. Tsunami deposits have been described from a low-lying area near Santa Barbara, and numerical modeling of tsunamis generated by hypothetical landslides in Santa Barbara Channel indicates a moderate to severe threat [Borrero, J.C., Dolan, J.F. and Synolakis, C.E., 2001. Tsunamis within the eastern Santa Barbara Channel. Geophys. Res. Lett., 28(4): 643-646.], involving wave runups of 2-20 m, for a range of assumed landslide volumes. Inundation from these waves, however, is expected to be highly focused so that only narrow (???10-km) sections of the shoreline would be affected. Crown Copyright ?? 2005 Published by Elsevier B.V. All rights reserved.

  7. Slovenian national landslide database as a basis for statistical assessment of landslide phenomena in Slovenia

    NASA Astrophysics Data System (ADS)

    Komac, Marko; Hribernik, Katarina

    2015-11-01

    Landslide databases on a national scale are an important tool for good spatial planning and for planning prevention measures or remediation activities. We have developed a modern national landslide database that enabled better landslide occurrence understanding, and will in the future help to assess landslide hazard, risk, potential damage, and enable more efficient landslide mitigation. In the paper landslide database construction steps and their properties are described. Following the collection of the landslide data from various sources and their input into the database the consistency of the database was assessed. Based on the data collected we have assessed basic statistical landslide properties, such as their overall spatial distribution, size and volume and the relation between them, landslide distribution in relation to engineering-geological units and different land-use, and past landslide mitigation activities. Analysis of landslide distribution also indicated areas in Slovenia where no landslide mapping was performed in the past, yet it should be, due to the high landslide susceptibility of these areas. Consequentially future national activities in relation to landslide problems should be governed primarily based on the findings of the database analyses to achieve the highest efficiency.

  8. Submarine landslides: processes, triggers and hazard prediction.

    PubMed

    Masson, D G; Harbitz, C B; Wynn, R B; Pedersen, G; Løvholt, F

    2006-08-15

    Huge landslides, mobilizing hundreds to thousands of km(3) of sediment and rock are ubiquitous in submarine settings ranging from the steepest volcanic island slopes to the gentlest muddy slopes of submarine deltas. Here, we summarize current knowledge of such landslides and the problems of assessing their hazard potential. The major hazards related to submarine landslides include destruction of seabed infrastructure, collapse of coastal areas into the sea and landslide-generated tsunamis. Most submarine slopes are inherently stable. Elevated pore pressures (leading to decreased frictional resistance to sliding) and specific weak layers within stratified sequences appear to be the key factors influencing landslide occurrence. Elevated pore pressures can result from normal depositional processes or from transient processes such as earthquake shaking; historical evidence suggests that the majority of large submarine landslides are triggered by earthquakes. Because of their tsunamigenic potential, ocean-island flank collapses and rockslides in fjords have been identified as the most dangerous of all landslide related hazards. Published models of ocean-island landslides mainly examine 'worst-case scenarios' that have a low probability of occurrence. Areas prone to submarine landsliding are relatively easy to identify, but we are still some way from being able to forecast individual events with precision. Monitoring of critical areas where landslides might be imminent and modelling landslide consequences so that appropriate mitigation strategies can be developed would appear to be areas where advances on current practice are possible. PMID:16844646

  9. Improving Landslide Susceptibility Modeling Using an Empirical Threshold Scheme for Excluding Landslide Deposition

    NASA Astrophysics Data System (ADS)

    Tsai, F.; Lai, J. S.; Chiang, S. H.

    2015-12-01

    Landslides are frequently triggered by typhoons and earthquakes in Taiwan, causing serious economic losses and human casualties. Remotely sensed images and geo-spatial data consisting of land-cover and environmental information have been widely used for producing landslide inventories and causative factors for slope stability analysis. Landslide susceptibility, on the other hand, can represent the spatial likelihood of landslide occurrence and is an important basis for landslide risk assessment. As multi-temporal satellite images become popular and affordable, they are commonly used to generate landslide inventories for subsequent analysis. However, it is usually difficult to distinguish different landslide sub-regions (scarp, debris flow, deposition etc.) directly from remote sensing imagery. Consequently, the extracted landslide extents using image-based visual interpretation and automatic detections may contain many depositions that may reduce the fidelity of the landslide susceptibility model. This study developed an empirical thresholding scheme based on terrain characteristics for eliminating depositions from detected landslide areas to improve landslide susceptibility modeling. In this study, Bayesian network classifier is utilized to build a landslide susceptibility model and to predict sequent rainfall-induced shallow landslides in the Shimen reservoir watershed located in northern Taiwan. Eleven causative factors are considered, including terrain slope, aspect, curvature, elevation, geology, land-use, NDVI, soil, distance to fault, river and road. Landslide areas detected using satellite images acquired before and after eight typhoons between 2004 to 2008 are collected as the main inventory for training and verification. In the analysis, previous landslide events are used as training data to predict the samples of the next event. The results are then compared with recorded landslide areas in the inventory to evaluate the accuracy. Experimental results

  10. Tien Shan Geohazards Database: Landslide susceptibility analysis

    NASA Astrophysics Data System (ADS)

    Havenith, H. B.; Torgoev, A.; Schlögel, R.; Braun, A.; Torgoev, I.; Ischuk, A.

    2015-11-01

    This paper is the second part of a new geohazards analysis applied to a large part of the Tien Shan, Central Asia, focused on landslide susceptibility computations that are based on recently compiled geographic, geological and geomorphological data. The core data are a digital elevation model, an updated earthquake catalogue, an active fault map as well as a new landslide inventory. The most recently added digital data are a new simplified geological map, an annual precipitation map, as well as river and road network maps that were produced for the Kyrgyz and Tajik parts of the Tien Shan. On the basis of these records we determine landslide densities with respect to morphological (M), geological (G), river distance (R), precipitation (P), earthquake (E) and fault (F) distance factors. Correlations were also established between scarp locations and the slope angle, distance to rivers, curvature. These correlations show that scarps tend to be located on steeper slopes, farther from rivers and on more convex terrain than the entire landslides. On the basis of the landslide density values computed for each class of the aforementioned factors, two landslide susceptibility maps are created according to the Landslide Factor analysis: the first one considers correlations between the landslide occurrences and the first four factors (MGRP); the second one is based on the first map (MGRP) combined with the seismo-tectonic influence (+ E + F) on landslide distributions. From the comparison of these two maps with actual landslide distributions we infer that the distances to rivers as well as to faults and past earthquakes most strongly constrain the susceptibility of slopes to landslides. We highlight several zones where the landslide susceptibilities computed for the MGRP + E + F factors fit better the observed concentration of landslides than those computed for the MGRP factors alone. For a few zones, both maps produce high landslide susceptibilities that do not well reflect

  11. Directions of the US Geological Survey Landslide Hazards Reduction Program

    USGS Publications Warehouse

    Wieczorek, G.F.

    1993-01-01

    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

  12. Landslide susceptibility assessment based on different rainfall-triggered landslide events

    NASA Astrophysics Data System (ADS)

    Oliveira, Sergio C.; Zêzere, José L.; Garcia, Ricardo A. C.

    2015-04-01

    The availability of several complete landslide event inventory maps associated to different rainfall conditions is uncommon for a single region. Nevertheless, it could contribute to a better recognition of the total extent and magnitude of landslides under specific triggering conditions. The motivation of the present work is related with three problems that should be solved: (i) How representative of the landslide activity and distribution in a study area can be a landslide event? (ii) How reliable can be a landslide event-based susceptibility map? (iii) How adequate can be a landslide event-based map to independent validate a landslide susceptibility map? To answer the previous questions two independent rainfall-triggered landslide event inventories, available for the Grande da Pipa river basin, north of Lisbon, Portugal, are used to assess landslide susceptibility at the regional scale. The 1983 landslide event was triggered by a single day of intense precipitation and originates 220 landslides that affected 0.15% (161413 m2) of the study area. The 2010 landslide event was associated with a long lasting rainfall period up to 90 days and generated 254 landslides that affected 0.46 % (511820 m2) of the study area. The two landslide-event inventories are compared according the following topics: (i) the landslide typology; (ii) the landslide morphometric characteristics; (iii) the analysis of the landslide predisposing factors; (iv) the assessment of magnitude-frequency relationships; (v) the predictive capability of landslide event-based susceptibility models. For the last topic, the Information Value method is used to establish the statistical relationships between the dependent landslide inventory map and the data-set of independent predisposing factors. Two landslide event-based susceptibility maps are produced using independently the landslide inventories of 1983 and 2010. The independent validation is obtained by crossing each landside susceptibility map with

  13. Lagrangian Hydrocode Simulations of Tsunamigenic, Subaerial Landslides

    NASA Astrophysics Data System (ADS)

    Schwaiger, H. F.; Parsons, J.; Higman, B.

    2006-12-01

    The interaction of debris flows, both subaqueous and subaerial, with bodies of water can produce tsunamis with a locally devastating impact. When debris flows begin above the water surface, the impact can produce a large air cavity, significantly increasing the effective volume of water displaced and complicating efforts to model the resulting tsunami. Because grid-based, Eulerian numerical methods have an inherent difficulty tracking material boundaries, we have implemented a particle-based, Lagrangian model (Smoothed Particle Hydrodynamics). The use of a particle model removes the common numerical difficulties associated with large deformation, multi-phase flows such as the numerical diffusion of material boundaries. We treat the debris flow as an incompressible, viscous fluid and the body of water as inviscid. Other rheologies of the debris flow (Mohr-Coulomb or Bingham plastic) can be included through the use of a non-linear viscosity. We apply this model to study the 1958 Lituya Bay landslide and resulting tsunami. Our simulation results compare favorably with field observations as well as a scaled laboratory experiment and a numerical study using an AMR Eulerian compressible fluid model.

  14. Scientists Investigate Recent Philippine Landslide

    NASA Astrophysics Data System (ADS)

    Lagmay, Alfredo Mahar A.; Ong, John Burtkenley T.; Fernandez, Dan Ferdinand D.; Lapus, Mark R.; Rodolfo, Raymond S.; Tengonciang, Arlene Mae P.; Soria, Janneli Lea A.; Baliatan, Eden G.; Quimba, Zareth L.; Uichanco, Christopher L.; Paguican, Engielle Mae R.; Remedio, Armelle Reca C.; Lorenzo, Genevieve Rose H.; Avila, Francia B.; Valdivia, Waldemar

    2006-03-01

    A massive landslide devastated the community of Barangay Guinsaugon, Municipality of St. Bernard, Southern Leyte Province, Philippines, at about 10:30 local time on 17 February. The landslide occurred along the steep fault scarp of the Philippine Fault Zone (PFZ) (Figure 1a), a large and active tectonic structure that traverses the entire length of the Philippines [Allen, 1962]. Barangay Guinsaugon is located at the foot of the scarp, directly in the path of the downward moving mass of earth. As of 24 February, the landslide caused 122 confirmed deaths; 1,328 people still are missing. To assist in the search and rescue operations that followed the landside, a team of geologists and physicists from the University of Philippines (UP-Diliman, Quezon City) and Ateneo de Manila University conducted an investigation of this area on 21-25 February. The UP-Ateneo team provided technical advice on the geology, which included the identification of the type and characteristics of the landslide.

  15. Landslides: A Question of Balance

    ERIC Educational Resources Information Center

    Devitt, John; Loader, Pete

    2008-01-01

    The impression given in some textbooks is that a landslide can be generated by increasing the weight of an unstable block or adding water to a potential slip plane. This demonstration, which might easily be adapted as a student investigation in physics at advanced level, was an attempt to rectify such oversimplifications and explain to students…

  16. Long runout mechanism of recent earthquake-triggered landslides in Japan and China

    NASA Astrophysics Data System (ADS)

    Fukuoka, Hiroshi; Wang, Gonghui; Miyagi, Toyohiko; Cui, Peng; Igwe, Ogbonnaya; Georgieva, Ekaterina

    2010-05-01

    path shows typical behavior of the Sliding surface liquefaction. Apparent friction angle can be calculated as only about 9.5 degrees. This small value can clearly show the high mobility of the landslide. 3. Long runout mechanism of scraping foreground soils and building foundation The main shock of the Wehchuan Earthquake caused two major landslides in Beichuan city, Wangjiayan landslide and Jingjiashan landslide. The former one slid into the city center and claimed lives of about 1,600, which is the largest casualty by a single landslide in the quake. It traveled very long distance and destroyed numerous buildings in the city center. Many buildings were flattened and wrecked into pieces in front of the toe of landslide mass of more than 100 meters wide. Other partly-destroyed buildings were inclined and apparently affected by partial upheaval or subsidence. Yin, et al. (2008) suggested that extremely strong air blasting caused by the rapid landslide mass movement could be the mechanism of flattening. However, similar experience was recorded in the 1985 Jizukiyama Landslide by torrential rainfall, and the 1995 Takarazuka Golf Course landslide triggered by the Kobe quake in Japan. In both cases, landslide mass ran scraping soils in front of the debris toe. This mechanism can be partly explained by quick and undrained loading by the rapid moving landslide mass onto the alluvial ground and the generated excess pore pressure.

  17. Effects of Bedrock Landsliding on Cosmogenically Determined Erosion Rates

    NASA Technical Reports Server (NTRS)

    Niemi, Nathan; Oskin, Mike; Burbank, Douglas; Heimsath, Arjun

    2005-01-01

    The successful quantification of long-term erosion rates underpins our understanding of landscape. formation, the topographic evolution of mountain ranges, and the mass balance within active orogens. The measurement of in situ-produced cosmogenic radionuclides (CRNs) in fluvial and alluvial sediments is perhaps the method with the greatest ability to provide such long-term erosion rates. In active orogens, however, deep-seated bedrock landsliding is an important erosional process, the effect of which on CRN-derived erosion rates is largely unquantified. We present a numerical simulation of cosmogenic nuclide production and distribution in landslide-dominated catchments to address the effect of bedrock landsliding on cosmogenic erosion rates in actively eroding landscapes. Results of the simulation indicate that the temporal stability of erosion rates determined from CRN concentrations in sediment decreases with increased ratios of landsliding to sediment detachment rates within a given catchment area, and that larger catchment areas must be sampled with increased frequency of landsliding in order to accurately evaluate long-term erosion rates. In addition, results of this simulation suggest that sediment sampling for CRNs is the appropriate method for determining long-term erosion rates in regions dominated by mass-wasting processes, while bedrock surface sampling for CRNs is generally an ineffective means of determining long-term erosion rates. Response times of CRN concentrations to changes in erosion rate indicate that climatically driven cycles of erosion may be detected relatively quickly after such changes occur, but that complete equilibration of CRN concentrations to new erosional conditions may take tens of thousands of years. Simulation results of CRN erosion rates are compared with a new, rich dataset of CRN concentrations from the Nepalese Himalaya, supporting conclusions drawn from the simulation.

  18. Landslide databases for applied landslide impact research: the example of the landslide database for the Federal Republic of Germany

    NASA Astrophysics Data System (ADS)

    Damm, Bodo; Klose, Martin

    2014-05-01

    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

  19. The Geomorphological Evolution of a Landscape in a Tectonically Active Region: the Sennwald Landslide

    NASA Astrophysics Data System (ADS)

    Aksay, Selçuk; Ivy-Ochs, Susan; Hippe, Kristina; Graemiger, Lorenz; Vockenhuber, Christof

    2016-04-01

    The Säntis nappe is a fold-and-thrust structure in eastern Switzerland consisting of numerous tectonic discontinuities that make rocks vulnerable to rock failure. The Sennwald landslide is one of those events that occurred due to the failure of Lower Cretaceous Helvetic limestones. This study reveals the surface exposure age of the event in relation to geological and tectonic setting, earthquake frequency of the Central Alps, and regional scale climate/weather influence. Our study comprises detailed mapping of landform features, thin section analysis of landslide boulder lithologies, landslide volume estimation, numerical DAN-3D run-out modelling, and the spatial and temporal relationship of the event. In the Sennwald landslide, 92 million m3 of limestones detached from the south-eastern wall of the Säntis nappe and slid with a maximum travel distance of ~4'500 m and a "fahrboeschung" angle of 15° along the SE-dipping sliding plane almost parallel to the orientation of the bedding plane. Numerical run-out modelling results match the extent and the thickness of landslide deposits as observed in the field. The original bedrock stratigraphy was preserved as geologically the top layer in the bedrock package travelled the farthest and the bottom layer came to rest closest to the release bedrock wall during the landslide. Velocities of maximum 90 m/s were obtained from the numerical run-out modelling. Total Cl and 36Cl were determined at ETH AMS facility with isotope dilution methods defined in the literature (Ivy-Ochs et al., 2004). Surface exposure ages of landslide deposits in the accumulation area are revealed from twelve boulders. The distribution of limestone boulders in the accumulation area, the exposure ages, and the numerical run-out modelling support the hypothesis that the Sennwald landslide was a single catastrophic event. The event is likely to have been triggered by at least light to moderate earthquakes (Mw=4.0-6.0). The historical and the last 40-year

  20. 3-Dimensional Imaging Modalities for Phenotyping Genetically Engineered Mice

    PubMed Central

    Powell, K. A.; Wilson, D.

    2013-01-01

    A variety of 3-dimensional (3D) digital imaging modalities are available for whole-body assessment of genetically engineered mice: magnetic resonance microscopy (MRM), X-ray microcomputed tomography (microCT), optical projection tomography (OPT), episcopic and cryoimaging, and ultrasound biomicroscopy (UBM). Embryo and adult mouse phenotyping can be accomplished at microscopy or near microscopy spatial resolutions using these modalities. MRM and microCT are particularly well-suited for evaluating structural information at the organ level, whereas episcopic and OPT imaging provide structural and functional information from molecular fluorescence imaging at the cellular level. UBM can be used to monitor embryonic development longitudinally in utero. Specimens are not significantly altered during preparation, and structures can be viewed in their native orientations. Technologies for rapid automated data acquisition and high-throughput phenotyping have been developed and continually improve as this exciting field evolves. PMID:22146851

  1. Protalign: a 3-dimensional protein alignment assessment tool.

    PubMed

    Meads, D; Hansen, M D; Pang, A

    1999-01-01

    Protein fold recognition (sometimes called threading) is the prediction of a protein's 3-dimensional shape based on its similarity to a protein of known structure. Fold predictions are low resolution; that is, no effort is made to rotate the protein's component amino acid side chains into their correct spatial orientations. The goal is simply to recognize the protein family member that most closely resembles the target sequence of unknown structure and to create a sensible alignment of the target to the known structure (i.e., a structure-sequence alignment). To facilitate this type of structure prediction, we have designed a low resolution molecular graphics tool. ProtAlign introduces the ability to interact with and edit alignments directly in the 3-dimensional structure as well as in the usual 2-dimensional layout. It also contains several functions and features to help the user assess areas within the alignment. ProtAlign implements an open pipe architecture to allow other programs to access its molecular graphics capabilities. In addition, it is capable of "driving" other programs. Because amino acid side chain orientation is not relevant in fold recognition, we represent amino acid residues as abstract shapes or glyphs much like Lego (tm) blocks and we borrow techniques from comparative flow visualization using streamlines to provide clean depictions of the entire protein model. By creating a low resolution representation of protein structure, we are able to at least double the amount of information on the screen. At the same time, we create a view that is not as busy as the corresponding representations using traditional high resolution visualization methods which show detailed atomic structure. This eliminates distracting and possibly misleading visual clutter resulting from the mapping of protein alignment information onto a high resolution display of the known structure. This molecular graphics program is implemented in Open GL to facilitate porting to

  2. Mathematical Modeling Applied to Prediction of Landslides in Southern Brazil

    NASA Astrophysics Data System (ADS)

    Silva, Lúcia; Araújo, João; Braga, Beatriz; Fernandes, Nelson

    2013-04-01

    after the landslide event. Numerical simulations with the SHALSTAB model were carried out in the basin and the results compared to the original location of the scars in the field. The results suggest that the combination of field mapping with the numerical simulation scenarios may contribute to the definition of better land management practices in such environment. Besides this, the replacement of the natural rain forest by huge banana plantations in this environment may have played a major role in defining the spatial distribution of landslides scars and the magnitude of the landslides generated.

  3. The landslide hazard in the San Francisco Bay region

    USGS Publications Warehouse

    Brabb, E.E.

    1977-01-01

    Development in hilly or mountainous terrain has resulted in much landslide damage. Areas susceptible to landsliding can be recognized. Practices for minimizing landslides are presented. ?? 1977 D. Reidel Publishing Company.

  4. Extreme Precipitation and High-Impact Landslides

    NASA Technical Reports Server (NTRS)

    Kirschbaum, Dalia; Adler, Robert; Huffman, George; Peters-Lidard, Christa

    2012-01-01

    It is well known that extreme or prolonged rainfall is the dominant trigger of landslides; however, there remain large uncertainties in characterizing the distribution of these hazards and meteorological triggers at the global scale. Researchers have evaluated the spatiotemporal distribution of extreme rainfall and landslides at local and regional scale primarily using in situ data, yet few studies have mapped rainfall-triggered landslide distribution globally due to the dearth of landslide data and consistent precipitation information. This research uses a newly developed Global Landslide Catalog (GLC) and a 13-year satellite-based precipitation record from Tropical Rainfall Measuring Mission (TRMM) data. For the first time, these two unique products provide the foundation to quantitatively evaluate the co-occurence of precipitation and rainfall-triggered landslides globally. The GLC, available from 2007 to the present, contains information on reported rainfall-triggered landslide events around the world using online media reports, disaster databases, etc. When evaluating this database, we observed that 2010 had a large number of high-impact landslide events relative to previous years. This study considers how variations in extreme and prolonged satellite-based rainfall are related to the distribution of landslides over the same time scales for three active landslide areas: Central America, the Himalayan Arc, and central-eastern China. Several test statistics confirm that TRMM rainfall generally scales with the observed increase in landslide reports and fatal events for 2010 and previous years over each region. These findings suggest that the co-occurrence of satellite precipitation and landslide reports may serve as a valuable indicator for characterizing the spatiotemporal distribution of landslide-prone areas in order to establish a global rainfall-triggered landslide climatology. This research also considers the sources for this extreme rainfall, citing

  5. Geophysical Survey To Understand Failure Mechanisms Involved On Deep Seated Landslides

    NASA Astrophysics Data System (ADS)

    Lebourg, T.; Tric, E.; Guglielmi, Y.; Cappa, F.; Charmoille, A.; Bouissou, S.

    2003-04-01

    The understanding of rupture processes involve on deep seated landslides and hence the prediction of such phenomenon is difficult for two main reasons. The first one, arise from the difficulty in estimating the mechanical behaviour of the whole mountain which is very different from that of a rock sample we can study on laboratory. This is mainly true in the upper part of slope subjected to weathering (Lebourg and al., 2002). The second reason, is due to the necessity of taking into account both the 3D geometry of the phenomenon and geological discontinuities affecting the mountain slide. We propose to show geophysical research on a deep seated landslide and the way we use to integreted then into numerical models. One of main problem of study deep seatted landslides with geophysical survey is the size of the landslide and the deep of the slope. The landslides we studied are located in the French Alps (Clapière landslide and Rocbillière landslide). It concern various geological formation, triggered by hydrological sollicitations. Our geophysical methods allow us to obtain 2D and 3D imagery of the geological structures, but also the shearing surface and the hydrological system used in the numerical and physical modeling. The research of the hydrogeological system can become one of the must importante result for the administration. After the first geophysical survey, we can quantify the hydrogeological level who can initiate or accelerate the paroxism of the landslide. Numerical model and prediction can also propose a 'surveillance' on the geophysical pseudo-dynamic prospecting. Our results showed also the importance of the weathering and the complexe chenalisation of the water whithin the slope, in the initiation of the movement. Our futur goal is to study the relative influence of the mechanical behaviour of the mountain, the behaviour of the wheathering zone, faults and intial topography of the mountain on landslide to determine the key parameter controlling this

  6. Analysis of hydrological triggered clayey landslides by small scale experiments

    NASA Astrophysics Data System (ADS)

    Spickermann, A.; Malet, J.-P.; van Asch, T. W. J.; Schanz, T.

    2010-05-01

    Hydrological processes, such as slope saturation by water, are a primary cause of landslides. This effect can occur in the form of e.g. intense rainfall, snowmelt or changes in ground-water levels. Hydrological processes can trigger a landslide and control subsequent movement. In order to forecast potential landslides, it is important to know both the mechanism leading to failure, to evaluate whether a slope will fail or not, and the mechanism that control the movement of the failure mass, to estimate how much material will move in which time. Despite numerous studies which have been done there is still uncertainty in the explanation of the processes determining the failure and post-failure. Background and motivation of the study is the Barcelonnette area that is part of the Ubaye Valley in the South French Alps which is highly affected by hydrological-controlled landslides in reworked black marls. Since landslide processes are too complex to understand it only by field observation experiments and computer calculations are used. The main focus of this work is to analyse the initialization of failure and the post-failure behaviour of hydrological triggered landslides in clays by small-scale experiments, namely by small-scale flume tests and centrifuge tests. Although a lot of effort is made to investigate the landslide problem by either small-scale or even large-scale slope experiments there is still no optimal solution. Small-scale flume tests are often criticised because of their scale-effect problems dominant in dense sands and cohesive material and boundary problems. By means of centrifuge tests the scale problem with respect to stress conditions is overcome. But also centrifuge testing is accompanied with problems. The objectives of the work are 1) to review potential failure and post-failure mechanisms, 2) to evaluate small-scale experiments, namely flume and centrifuge tests in the analysis of the failure behaviour in clayey slopes and 3) to interpret the

  7. Theory of relativistic Brownian motion: the (1+3) -dimensional case.

    PubMed

    Dunkel, Jörn; Hänggi, Peter

    2005-09-01

    A theory for (1+3) -dimensional relativistic Brownian motion under the influence of external force fields is put forward. Starting out from a set of relativistically covariant, but multiplicative Langevin equations we describe the relativistic stochastic dynamics of a forced Brownian particle. The corresponding Fokker-Planck equations are studied in the laboratory frame coordinates. In particular, the stochastic integration prescription--i.e., the discretization rule dilemma--is elucidated (prepoint discretization rule versus midpoint discretization rule versus postpoint discretization rule). Remarkably, within our relativistic scheme we find that the postpoint rule (or the transport form) yields the only Fokker-Planck dynamics from which the relativistic Maxwell-Boltzmann statistics is recovered as the stationary solution. The relativistic velocity effects become distinctly more pronounced by going from one to three spatial dimensions. Moreover, we present numerical results for the asymptotic mean-square displacement of a free relativistic Brownian particle moving in 1+3 dimensions. PMID:16241514

  8. Landslides and glacier fall - ice/debris avalanches triggered by the April 2015 Gorkha Earthquake, Nepal

    NASA Astrophysics Data System (ADS)

    Fukuoka, Hiroshi; Bhandari, Netra Prakash; Adhikari, Basanta Raj; Yamasaki, Shintaro

    2016-04-01

    On 25 April 2015, a large-scale earthquake of M7.8 attacked central Nepal. Epicenter is located in Gorkha, west of Kathmandu. Aftershocks epicenter area extended about 100 km long and 150 km wide. Acceleration records inside Kathmandu basin show that the main shock predominant period is 3 - 5 s and PGA is smaller than 0.2 g, because of underneath thick deposits. Japanese expert investigation team dispatched immediately after the quake found numerous small- to large-scale landslides in the earthquake fault rupture zone except Kathmandu basin. Those characteristics are (1) number of larger landslides are much smaller than expected from the main shock magnitude, (2) uncountable rock falls were observed which claimed casualties in the mountain communities; (3) as many landslides were reactivated since the main/after-shock area are occupied by landslide-prone hill slopes; (4) some large-scale rock slides resulting in landslide dam creation, were confirmed by the immediate satellite imagery analysis; (5) In the Langtang village in Himalaya mountains, an hanging glacier fall - ice/debris avalanche was triggered, claiming the lives of all the residents and trekkers staying in the community. Authors had returned debris sample to Japan, trying to apply geotechnical tests for mechanism study; (6) subsidence sites along the highway of artificial fills and adjacent communities of Kathmandu were observed; (7) Small-scale landslides and subsidence were observed in some of UNESCO's World heritage sites.

  9. Numerical model of electromagnetic scattering off a subterranean 3-dimensional dielectric

    SciTech Connect

    Dease, C.G.; Didwall, E.M.

    1983-08-01

    As part of the effort to develop On-Site Inspection (OSI) techniques for verification of compliance to a Comprehensive Test Ban Treaty (CTBT), a computer code was developed to predict the interaction of an electromagnetic (EM) wave with an underground cavity. Results from the code were used to evaluate the use of surface electromagnetic exploration techniques for detection of underground cavities or rubble-filled regions characteristic of underground nuclear explosions.

  10. Landslide-Generated Tsunami Model for Quick Hazard Assessment

    NASA Astrophysics Data System (ADS)

    Franz, M.; Rudaz, B.; Locat, J.; Jaboyedoff, M.; Podladchikov, Y.

    2015-12-01

    Alpine regions are likely to be areas at risk regarding to landslide-induced tsunamis, because of the proximity between lakes and potential instabilities and due to the concentration of the population in valleys and on the lakes shores. In particular, dam lakes are often surrounded by steep slopes and frequently affect the stability of the banks. In order to assess comprehensively this phenomenon together with the induced risks, we have developed a 2.5D numerical model which aims to simulate the propagation of the landslide, the generation and the propagation of the wave and eventually the spread on the shores or the associated downstream flow. To perform this task, the process is done in three steps. Firstly, the geometry of the sliding mass is constructed using the Sloping Local Base Level (SLBL) concept. Secondly, the propagation of this volume is performed using a model based on viscous flow equations. Finally, the wave generation and its propagation are simulated using the shallow water equations stabilized by the Lax-Friedrichs scheme. The transition between wet and dry bed is performed by the combination of the two latter sets of equations. The proper behavior of our model is demonstrated by; (1) numerical tests from Toro (2001), and (2) by comparison with a real event where the horizontal run-up distance is known (Nicolet landslide, Quebec, Canada). The model is of particular interest due to its ability to perform quickly the 2.5D geometric model of the landslide, the tsunami simulation and, consequently, the hazard assessment.

  11. Oregon earthquakes increase local landslide risk

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-11-01

    Coastal Oregon is home to a number of slow, recurrent landslides. During bouts of heavy rain, water gets into the soil, reducing friction and causing the ground to slip. Often, these landslides creep along at a barely perceptible rate—less than a centimeter per day. Yet the landslides are a lurking threat, as past events that have damaged infrastructure and cut communities off for months at a time have demonstrated.

  12. Field monitoring of the Corvara landslide (Dolomites, Italy) and its relevance for hazard assessment

    NASA Astrophysics Data System (ADS)

    Corsini, Alessandro; Pasuto, A.; Soldati, M.; Zannoni, A.

    2005-03-01

    The Corvara landslide is an active slow moving rotational earth slide - earth flow, located uphill of the village of Corvara in Badia, one of the main tourist centres in the Alta Badia valley in the Dolomites (Province of Bolzano, Italy). Present-day movements of the Corvara landslide cause National Road 244 and other infrastructures to be damaged on a yearly basis. The movements also give rise to more serious risk scenarios for some buildings located in front the toe of the landslide. For these reasons, the landslide has been under observation since 1997 with various field devices that enable slope movements to be monitored for hazard assessment purposes. Differential GPS measurements on a network of 47 benchmarks has shown that horizontal movements at the surface of the landslide have ranged from a few centimetres to more than 1 m between September 2001 and September 2002. Over the same period, vertical movements ranged from a few centimetres to about 10 cm, with the maximum displacement rate being recorded in the track zone and in the uppermost part of the accumulation lobe of the landslide. Borehole systems, such as inclinometers and TDR cables, have recorded similar rates of movement, with the depths of the major active shear surfaces ranging from 48 m to about 10 m. From these data, it is estimated that the active component of the landslide has a volume of about 50 million m 3. In this paper the monitoring data collected so far are presented and discussed in detail to prove that the hazard for the Corvara landslide, considered as the product of yearly probability of occurrence and magnitude of the phenomenon, can be regarded has as medium or high if the velocity or alternatively the volume involved is considered. Finally, it is also concluded that the monitoring results obtained provide a sound basis on which to develop and validate numerical models, manage hazard and support the identification of viable passive and active mitigation measures.

  13. Physical Limits on the Predictability of Erosion and Sediment Transport by Landslides and Debris Flows

    NASA Astrophysics Data System (ADS)

    Iverson, R. M.

    2015-12-01

    Episodic landslides and debris flows play a key role in sculpting many steep landscapes, and they also pose significant natural hazards. Field evidence, laboratory experiments, and theoretical analyses show that variations in the quantity, speed, and distance of sediment transport by landslides and debris flows can depend strongly on nuanced differences in initial conditions. Moreover, initial conditions themselves can be strongly dependent on the geological legacy of prior events. The scope of these dependencies is revealed by the results of landslide dynamics experiments [Iverson et al., Science, 2000], debris-flow erosion experiments [Iverson et al., Nature Geosci., 2011], and numerical simulations of the highly destructive 2014 Oso, Washington, landslide [Iverson et al., Earth Planet. Sci. Let., 2015]. In each of these cases, feedbacks between basal sediment deformation and pore-pressure generation cause the speed and distance of sediment transport to be very sensitive to subtle differences in the ambient sediment porosity and water content. On the other hand, the onset of most landslides and debris flows depends largely on pore-water pressure distributions and only indirectly on sediment porosity and water content. Thus, even if perfect predictions of the locations and timing of landslides and debris flows were available, the dynamics of the events - and their consequent hazards and sediment transport - would be difficult to predict. This difficulty is a manifestation of the nonlinear physics involved, rather than of poor understanding of those physics. Consequently, physically based models for assessing the hazards and sediment transport due to landslides and debris flows must take into account both evolving nonlinear dynamics and inherent uncertainties about initial conditions. By contrast, landscape evolution models that use prescribed algebraic formulas to represent sediment transport by landslides and debris flows lack a sound physical basis.

  14. Causes and mobility of large volcanic landslides: application to Tenerife, Canary Islands

    NASA Astrophysics Data System (ADS)

    Hürlimann, M.; Garcia-Piera, J. O.; Ledesma, A.

    2000-12-01

    Giant volcanic landslides are one of the most hazardous geological processes due to their volume and velocity. Since the 1980 eruption and associated debris avalanche of Mount St. Helens hundreds of similar events have been recognised worldwide both on continental volcanoes and volcanic oceanic islands. However, the causes and mobility of these enormous mass movements remain unresolved. Tenerife exhibits three voluminous subaerial valleys and a wide offshore apron of landslide debris produced by recurrent flank failures with ages ranging from Upper Pliocene to Middle Pleistocene. We have selected the La Orotava landslide for analysis of its causes and mobility using a variety of simple numerical models. First, the causes of the landslide have been evaluated using Limit Equilibrium Method and 2D Finite Difference techniques. Conventional parameters including hydrostatic pore pressure and material strength properties, together with three external processes, dike intrusion, caldera collapse and seismicity, have been incorporated into the stability models. The results indicate that each of the external mechanism studied is capable of initiating slope failures. However, we propose that a combination of these processes may be the most probable cause for giant volcanic landslides. Second, we have analysed the runout distance of the landslide using a simple model treating both the subaerial and submarine parts of the sliding path. The effect of the friction coefficient, drag forces and hydroplaning has been incorporated into the model. The results indicate that hydroplaning particularly can significantly increase the mobility of the landslide, which may reach runout distances greater than 70 km. The models presented are not considered definite and have mainly a conceptual purpose. However, they provide a physical basis from which to better interpret these complex geologic phenomena and should be taken into account in the prediction of future events and the assessment of

  15. Quick Analysis Method for Estimating Debris Flow Prone Area Caused by Overflow from Landslide dam

    NASA Astrophysics Data System (ADS)

    Shimizu, T.; Uchida, T.; Yamakoshi, T.; Yoshino, K.; Kisa, H.; Ishizuka, T.; Kaji, A.

    2012-04-01

    When earthquake or torrential rainfall cause deep catastrophic landslides, landslide dams can be formed in mountainous region. If water overflows from the landslide dams, large scale debris flow can occurs and possibly causes serious disasters in the downward region. Debris flow caused by the overflow from landslide dam is possible to affect the larger area than normal debris flow and flash flood. It is important for both a decision maker and resident in the area to recognize the disaster prone area as early as possible. For that reason, it is important to establish a quick analysis method for estimating debris flow prone area caused by overflow from landslide dams under the emergency situation. This situation requires the method to have both accuracy and speed for release. Nonetheless these two factors have trade-off relationship. We recently developed the quick analysis method to estimate debris flow disaster prone area caused by overflow from landslide dams. The method including the ways of efficient survey and numerical simulation programs called QUAD-L (QUick Analysis system for Debris flow caused by Landslide dam overflow). Our quick analysis system was actually applied to show the area for evacuation against debris flow caused by overflow from landslide dam formed by the 2011 Typhoon Talas which hit mainly the central region of Japan on September 2-4th, 2011. In addition to background of this application, since May 1st, 2011, Erosion and Sediment Control (SABO) Department of the Ministry of Land, Infrastructure, Transport and Tourism, Japan (MLIT) launched a new scheme using above-mentioned quick analysis method.

  16. Environmental impact of the landslides caused by the 12 May 2008, Wenchuan, China earthquake

    USGS Publications Warehouse

    Highland, Lynn; Sun, Ping

    2013-01-01

    The magnitude 7.9 (Mw) Wenchuan, China, earthquake of May 12, 2008 caused at least 88,000 deaths of which one third are estimated to be due to the more than 56,000 earthquake-induced landslides. The affected area is mountainous, featuring densely-vegetated, steep slopes through which narrowly confined rivers and streams flow. Numerous types of landslides occurred in the area, including rock avalanches, rock falls, translational and rotational slides, lateral spreads and debris flows. Some landslides mobilized hundreds of million cubic meters of material, often resulting in the damming of rivers and streams, impacting river ecosystems and morphology. Through an extensive search of both Chinese- and English-language publications we provide a summary of pertinent research on environmental effects, emphasizing key findings. Environmental effects caused by landslides include the alteration of agriculture, changes to natural ecosystems, changes in river morphology due to landslide dams and other effects such as sedimentation and flooding. Damage by landslides to the giant panda reserve infrastructure and habitat, was severe, threatening the survival of one of the world’s rarest species. The Panda reserves are of national significance to China, and to the vital tourism economy of the region. One of the major impacts to both the natural and built environment is the complete relocation of some human populations and infrastructure to new areas, resulting in the abandonment of towns and other areas that were damaged by the earthquake and landslides. The landslide effects have affected the biodiversity of the affected area, and it has been hypothesized that strict forest preservation measures taken in the years preceding the earthquake resulted in a reduction of the environmental damage to the area.

  17. Geomorphological, pedological and dendrochronological signatures of a relict landslide terrain, Mt Garbatka (Kamienne Mts), SW Poland

    NASA Astrophysics Data System (ADS)

    Migoń, Piotr; Kacprzak, Andrzej; Malik, Ireneusz; Kasprzak, Marek; Owczarek, Piotr; Wistuba, Małgorzata; Pánek, Tomaš

    2014-08-01

    In the Kamienne Mountains the largest concentration of apparently relict landslides in the Sudetes range occurs. On the northern slopes of Mt Garbatka mass movements re-shaped two adjacent slope hollows and a wide depositional area is located down the valley. The main landslide body is nearly 1 km long and 200-300 m wide. Its flattened surface morphology and the occurrence of large dispersed allochtonous boulders in the distal part suggests a flow-like movement, initiated by shallow translational slides in the upper slopes. The thickness of colluvium, determined by an ERT survey, may reach 10 m. Geomorphic signatures of mass movement are subdued, suggesting that considerable time has elapsed since the origin of the landslide and that large-scale mass movements are likely pre-Holocene in age. This is consistent with the results of an extensive soil survey within the landslide body and on the surrounding slopes. Similarity of soil properties and well-developed horizonation of profiles both within the landslide and outside it shows that no major disturbance has taken place during the soil formation period. Dendrogeomorphological research, in turn, yielded evidence of numerous growth disturbances recorded in tree rings of Norway spruce growing on the landslide body. These signals are interpreted that the slope surface is not entirely stable under current environmental conditions. Flow or creep of landslide material is not very likely, given the characteristics of cover materials, and it is hypothesized that dendrochronological signals develop in response to ground deformation through piping and throughflow. Landslide hazard in the valley below Mt Garbatka appears low at present but to claim complete stability would be premature.

  18. A dynamic landslide hazard assessment system for Central America and Hispaniola

    NASA Astrophysics Data System (ADS)

    Kirschbaum, D. B.; Stanley, T.; Simmons, J.

    2015-10-01

    Landslides pose a serious threat to life and property in Central America and the Caribbean Islands. In order to allow regionally coordinated situational awareness and disaster response, an online decision support system was created. At its core is a new flexible framework for evaluating potential landslide activity in near real time: Landslide Hazard Assessment for Situational Awareness. This framework was implemented in Central America and the Caribbean by integrating a regional susceptibility map and satellite-based rainfall estimates into a binary decision tree, considering both daily and antecedent rainfall. Using a regionally distributed, percentile-based threshold approach, the model outputs a pixel-by-pixel nowcast in near real time at a resolution of 30 arcsec to identify areas of moderate and high landslide hazard. The daily and antecedent rainfall thresholds in the model are calibrated using a subset of the Global Landslide Catalog in Central America available for 2007-2013. The model was then evaluated with data for 2014. Results suggest reasonable model skill over Central America and poorer performance over Hispaniola due primarily to the limited availability of calibration and validation data. The landslide model framework presented here demonstrates the capability to utilize globally available satellite products for regional landslide hazard assessment. It also provides a flexible framework to interchange the individual model components and adjust or calibrate thresholds based on access to new data and calibration sources. The availability of free satellite-based near real-time rainfall data allows the creation of similar models for any study area with a spatiotemporal record of landslide events. This method may also incorporate other hydrological or atmospheric variables such as numerical weather forecasts or satellite-based soil moisture estimates within this decision tree approach for improved hazard analysis.

  19. A dynamic landslide hazard assessment system for Central America and Hispaniola

    NASA Astrophysics Data System (ADS)

    Kirschbaum, D. B.; Stanley, T.; Simmons, J.

    2015-04-01

    Landslides pose a serious threat to life and property in Central America and the Caribbean Islands. In order to allow regionally coordinated situational awareness and disaster response, an online decision support system was created. At its core is a new flexible framework for evaluating potential landslide activity in near real-time: Landslide Hazard Assessment for Situational Awareness. This framework was implemented in Central America and the Caribbean by integrating a regional susceptibility map and satellite-based rainfall estimates into a binary decision tree, considering both daily and antecedent rainfall. Using a regionally distributed, percentile-based threshold approach, the model outputs a pixel-by-pixel nowcast in near real-time at a resolution of 30 arcsec to identify areas of moderate and high landslide hazard. The daily and antecedent rainfall thresholds in the model are calibrated using a subset of the Global Landslide Catalog in Central America available for 2007-2013. The model was then evaluated with data for 2014. Results suggest reasonable model skill over Central America and poorer performance over Hispaniola, due primarily to the limited availability of calibration and validation data. The landslide model framework presented here demonstrates the capability to utilize globally available satellite products for regional landslide hazard assessment. It also provides a flexible framework to interchange the indiviual model components and adjust or calibrate thresholds based on access to new data and calibration sources. The availability of free, satellite-based near real-time rainfall data allows the creation of similar models for any study area with a spatiotemporal record of landslide events. This method may also incorporate other hydrological or atmospheric variables such as numerical weather forecasts or satellite-based soil moisture estimates within this decision tree approach for improved hazard analysis.

  20. 3D modelling of slow landslides: the Portalet case study (Spain)

    NASA Astrophysics Data System (ADS)

    Fernandez-Merodo, Jose Antonio; Bru, Guadalupe; García-Davalillo, Juan Carlos; Herrera, Gerardo; Fernandez, Jose

    2014-05-01

    Slow landslide deformation evolution is generally cast using 1D or 2D numerical models. This paper aims to explore 3D effects on the kinematic behavior of a real landslide, the Portalet landslide (Central Spanish Pyrenees). This is a very well characterized and documented active paleo-landslide that has been reactivated by the construction of a parking area at the toe of the slope. The proposed 3D model is based on a time dependent hydro-mechanical finite element formulation that takes into account i) groundwater changes due to daily rainfall records and ii) viscous behavior and delayed creep deformation through a viscoplastic constitutive model based on Perzyna's theory. The model reproduces the nearly constant strain rate (secondary creep) and the acceleration/deceleration of the moving mass due to hydrological changes. Furthermore, the model is a able to catch the superficial 3D kinematics revealed by advanced in-situ monitoring like ground based SAR or DInSAR processing of satellite SAR images. References [1] Herrera G, Fernández-Merodo JA, Mulas J, Pastor M, Luzi G, Monserrat O (2009) A landslide forecasting model using ground based SAR data: The Portalet case study. Engineering Geology 105: 220-230 [2] Fernández-Merodo JA, Herrera G, Mira P, Mulas J, Pastor M, Noferini L, Me-catti D and Luzi G (2008). Modelling the Portalet landslide mobility (Formigal, Spain). iEMSs 2008: International Congress on Environmental Modelling and Software. Sànchez-Marrè M, Béjar J, Comas J, Rizzoli A and Guariso G (Eds.) International Environmental Modelling and Software Society (iEMSs) [3] Fernández-Merodo JA, García-Davalillo JC, Herrera G, Mira P, Pastor M (2012). 2D visco-plastic finite element modelling of slow landslides: the Portalet case study (Spain). Landslides, DOI: 10.1007/s10346-012-0370-4

  1. Venus - Landslide in Navka Region

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Magellan spacecraft has observed remnant landslide deposits apparently resulting from the collapse of volcanic structures. This Magellan radar image is centered about 25.4 degrees south latitude and 308 degrees east longitude in the southwestern Navka Region of Venus. The image shows a 17.4 kilometer (10.8 mile) diameter volcanic dome on the plains. The dome is approximately 1.86 kilometers (1.2 mile) in height and it has a slope of about 23 degrees. The northwest and northeast flanks of the dome have collapsed to form landslides that have deposited debris on the plains. The image shows an area 110 kilometers (68 miles) across and 100 kilometers (62 miles) in length.

  2. ECONOMIC LOSSES AND FATALITIES DUE TO LANDSLIDES.

    USGS Publications Warehouse

    Schuster, Robert L.; Fleming, Robert W.

    1986-01-01

    Annual losses in the United States, Japan, Italy, and India have been estimated at 1 billion or more each. During the period 1971-74, nearly 600 people per year were killed by landslides worldwide; about 90 percent of these deaths occurred in the Circum-Pacific region. From 1967-82, 150 people per year died in Japan as a result of slope failures. In the United States, the number of landslide-related fatalities per year exceeds 25. Japan leads other nations in development of comprehensive programs to reduce economic losses and fatalities due to landslides. The United States recently has proposed a national landslide hazard reduction program.

  3. Mapping and analysis of Martian landslides

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni B.; Frattini, Paolo; Valbuzzi, Elena; Russo, Valeria

    2013-04-01

    This work is part of a larger effort aimed to a more quantitative description of landslide phenomena on Mars and the understanding of rock mass properties and landslide mobility with respect to their Earth equivalents. Recently, large satellite imagery datasets have become available and they have been mosaicked in different suitable tools making mapping an easier job than before. Furthermore, the availability of other georeferenced database makes possible and easily feasible some spatially distributed analyses. We prepared a new landslide inventory to acquire information about: landslide size distribution and areal density, controls of geometrical condition along Martian slopes, landslide typology and mechanism, relationship with impact craters distribution, runout, volume estimates, characteristic features. We adopted Google Earth, Google, Inc. as a mapping tool using both visible and CTX images. Landslides have been mapped according to standard geomorphological criteria, by two landslide experts delineating both the landslide scar and accumulation limits, associating each scarp to a deposit. Multiple accumulations have been differentiated where possible to obtain a more sound dataset. We prevalently mapped landslides located along the Martian valleys and Chasma flanks with only minor attention to classical block and slump instabilities typical of crater rim failures. This because we were mainly interested in long runout landslides or complex failures which could allow to define some rock mass characteristics along these slopes, and to study landslide mobility with respect to Earth equivalent phenomena. So long runout landslides have been mapped also when recognized within crater rims. Topographic characteristics have been extracted by means of the available MOLA dataset. The inventory presently consists of 1232 landslides covering a total area of about 180,000 km2. Landslide size ranges from 0.15 km2 to a maximum of 12,000 km2. We examined area

  4. How different are the results acquired from mathematical and subjective methods in dendrogeomorphology? Insights from landslide movements

    NASA Astrophysics Data System (ADS)

    Šilhán, Karel

    2016-01-01

    Knowledge of past landslide activity is crucial for understanding landslide behaviour and for modelling potential future landslide occurrence. Dendrogeomorphic approaches represent the most precise methods of landslide dating (where trees annually create tree-rings in the timescale of up to several hundred years). Despite the advantages of these methods, many open questions remain. One of the less researched uncertainties, and the focus of this study, is the impact of two common methods of geomorphic signal extraction on the spatial and temporal results of landslide reconstruction. In total, 93 Norway spruce (Picea abies (L.) Karst.) trees were sampled at one landslide location dominated by block-type movements in the forefield of the Orlické hory Mts., Bohemian Massif. Landslide signals were examined by the classical subjective method based on reaction (compression) wood analysis and by a numerical method based on eccentric growth analysis. The chronology of landslide movements obtained by the mathematical method resulted in twice the number of events detected compared to the subjective method. This finding indicates that eccentric growth is a more accurate indicator for landslide movements than the classical analysis of reaction wood. The reconstructed spatial activity of landslide movements shows a similar distribution of recurrence intervals (Ri) for both methods. The differences (maximally 30% of the total Ri ranges) in results obtained by both methods may be caused by differences in the ability of trees to react to tilting of their stems by a specific growth response (reaction wood formation or eccentric growth). Finally, the ability of trees to record tilting events (by both growth responses) in their tree-ring series was analysed for different decades of tree life. The highest sensitivity to external tilting events occurred at tree ages from 70 to 80 years for reaction wood formation and from 80 to 90 years for eccentric growth response. This means that

  5. Venus - Volcano With Massive Landslides

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This Magellan full-resolution mosaic which covers an area 143 by 146 kilometers (89 by 91 miles) is centered at 55 degrees north latitude, 266 degrees east longitude. The bright feature, slightly south of center is interpreted to be a volcano, 15-20 kilometers (9.3 to 12.4 miles) in diameter with a large apron of blocky debris to its right and some smaller aprons to its left. A preferred explanation is that several massive catastrophic landslides dropped down steep slopes and were carried by their momentum out into the smooth, dark lava plains. At the base of the east-facing or largest scallop on the volcano is what appears to be a large block of coherent rock, 8 to 10 kilometers (5 to 6 miles) in length. The similar margin of both the scallop and block and the shape in general is typical of terrestrial slumped blocks (masses of rock which slide and rotate down a slope instead of breaking apart and tumbling). The bright lobe to the south of the volcano may either be a lava flow or finer debris from other landslides. This volcanic feature, characterized by its scalloped flanks is part of a class of volcanoes called scalloped or collapsed domes of which there are more than 80 on Venus. Based on the chute-like shapes of the scallops and the existence of a spectrum of intermediate to well defined examples, it is hypothesized that all of the scallops are remnants of landslides even though the landslide debris is often not visible. Possible explanations for the missing debris are that it may have been covered by lava flows, the debris may have weathered or that the radar may not be recognizing it because the individual blocks are too small

  6. An Atlas of ShakeMaps for Landslide and Liquefaction Modeling

    NASA Astrophysics Data System (ADS)

    Johnson, K. L.; Nowicki, M. A.; Mah, R. T.; Garcia, D.; Harp, E. L.; Godt, J. W.; Lin, K.; Wald, D. J.

    2012-12-01

    et al., this meeting, for more detail on the regression). To make the ShakeMap and PAGER systems more comprehensive in terms of secondary losses, we are working to calibrate a similarly constrained regression for liquefaction estimation using a suite of well-studied earthquakes for which detailed, digitized liquefaction datasets are available; here variants of wetness index and soil strength replace geology and slope. We expect that this Atlas of ShakeMaps for landslide and liquefaction case history events, which will soon be publicly available via the internet, will aid in improving the accuracy of loss-modeling systems such as PAGER, as well as allow for a common framework for numerous other mechanistic and empirical studies.

  7. Landslide Mobility and Hazards: A Geophysical Overview of the Oso Disaster

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    Some landslides move slowly or intermittently downslope, whereas others accelerate catastrophically and run out long distances across flat or gently sloping terrain. Seldom does landsliding of one type transition abruptly into the other, however, and seldom are the consequences more severe than at a site near Oso, Washington, where more than 40 fatalities resulted from a high-speed, long-runout landslide on 22 March 2014. Our interpretations of seismic data inversions and eyewitness accounts indicate that the Oso event began gradually, with remobilization of old landslide deposits that were unusually wet due to months of exceptional precipitation. For about 50 s, relatively slow downslope motion of these deposits withdrew support from a bluff above them, and then the bluff collapsed abruptly. This collapse radiated strong broadband seismic energy and rapidly loaded the old landslide material downslope. We infer that this rapid loading of previously dilated landslide debris caused contractive deformation, widespread liquefaction, and runaway acceleration. The resulting debris avalanche flow (DAF) had a volume of 8 ×106 m3and a fahrböschung (H/L ratio) of 0.106, making it exceptionally mobile for a landslide of its size. The leading edge of the Oso DAF may have gained mobility by entraining water as it displaced the adjacent Stillaguamish River and by liquefying wet floodplain sediments as it overran them, and it formed distal deposits that resembled those of many wood-freighted debris flows. The transition from relatively slow landslide motion (which had occurred intermittently for decades at the Oso site) to high-speed motion and long runout appears to have been very sensitive to contingencies. Our simulations of the Oso event using a new numerical model (D-Claw) show that small differences in water-saturated porosity (n) were sufficient to cause divergent landslide behaviors. In a case with n = 0.38, D-Claw predicts runaway liquefaction and high-speed runout

  8. Hazard assessment of landslide and debris flow in the Rjeina river valley, Croatia

    NASA Astrophysics Data System (ADS)

    Wang, Chunxiang; Watanabe, Naoki; Marui, Hideaki

    2013-04-01

    The Rječina River extends approximately 18.7km long and flows into the Adriatic Sea at the center of Rijeka City, Croatia. Landslide, debris flow and rockfall are main geohazards in the middle part of the Rječina river basin. The zone between the Valići reservoir dam and the Pasac Bridge is particularly the most unstable and hazardous area in the river basin. The Grohovo landslide in the middle part of the river basin is located on the valley's slope facing southwest and situated at just downstream of the Valići dam. This landslide is the largest active landslide along the Adriatic Sea coast in Croatia. Assuming that serious heavy rainfall or earthquake occurs, it is most likely to occur two types of geohazard event. One scenario is that the debris deposited on the Grohovo landslide will move down to the channel of the Rječina River and dam up the river course. Another scenario is that the slope deposits on the landslide will be mixed with water and subsequently turn into a debris flow reaching to Rijeka City. We simulate both two cases of the formation of landslide-dam and the occurrence of debris-flow by two integrated models using GIS to represent the dynamic process across 3D terrains. In the case of the formation of landslide-dam, it is assumed that slope deposits will move downhill after failing along a shear zone. GIS-based revised Hovland's 3D limit equilibrium model is used to simulate the movement and stoppage of the slope deposits to form landslide-dam. The 3D factor of safety will be calculated step by step during the sliding process simulation. Stoppage is defined by the factor of safety much greater than one and the velocity equal to zero. The simulation result shows that the height of the landslide-dam will be nine meters. In case of debris flow, the mixture of slope deposits and water will be differentiated from landslide by fluid-like deformation of the mobilized material. GIS-based depth-averaged 2D numerical model is used to predict the

  9. How seismic waves can be used to understand and constrain landslide dynamics

    NASA Astrophysics Data System (ADS)

    Mangeney, A.; Favreau, P.; Moretti, L.; Lucas, A.; Le Friant, A.; Bouchut, F.

    2010-12-01

    Gravitational instabilities such as debris flows, landslide or avalanches play a key role in erosion processes on the Earth’s surface and represent one of the major natural hazard threatening life and property in mountainous, volcanic, seismic and coastal areas. Despite the great amount of experimental, numerical and field studies, the understanding of landslide dynamics is still an open question. In particular, there is no consensus to explain the high mobility of natural avalanches. Field measurements relevant to the dynamics of natural landslides are scarce. This is due to their unpredictability and destructive power and prevents detailed investigation of the mechanical properties of the flowing material. Recent studies have shown that the seismic signal generated by landslides provides a unique way to detect gravitational instabilities and to get information on their dynamics and geometrical characteristics. In particular, Favreau et al. [2009] show that simulation of landslides and generated seismic waves reproduce the main features of the recorded low frequency seismic signal, making it possible to discriminate between possible alternative scenarios for flow dynamics and to provide first estimates of the rheological parameters. We propose here to go further in this direction by investigating the following key questions: What is the effect of the topography and of the landslide volume on the generated seismic signal? What is the sensitivity of the generated seismic signal to the mechanical behavior of the landslide? At what distance and frequency is the point source approximation correct? To address these issues, numerical simulation of two well constrained landslides has been performed: the 2.5 Mm3 Thurwieser landslide that occurred in Italy in 2004 and the 60 Mm3 Boxing Day debris avalanche that occurred in Montserrat in 1997 during the volcanic eruption. For both landslides, simulation shows the major role of topography curvature on the generated seismic

  10. Landslide Economics: Concepts and Case Studies

    NASA Astrophysics Data System (ADS)

    Klose, Martin; Damm, Bodo

    2015-04-01

    Landslide economics is vital for fundamental understanding of landslide risk as dealing with two important topics: (i) impact assessment, either as damage statistics or cost modeling, and (ii) vulnerability assessment, i.e., the study of exposure, sensitivity, and resilience to landslide damage, ideally from both sociotechnical and financial perspective (e.g., Crovelli and Coe, 2009; Wills et al., 2014). Many aspects addressed in landslide economics have direct influence on landslide risk, including: (i) human activity is often a major causative factor of landslides, not only by predisposing or triggering them, but also as a result of inadequate (low-cost) landslide mitigation; (ii) the level of tolerable or acceptable risk, a measure driving a large part of landslide costs in industrialized countries, is highly variable, differing between individuals, public or private organizations, and societies, with its nature being to change over time; and (iii) decision makers are faced with finding the right balance in landslide mitigation, thus need to weight diverse geological and socioeconomic factors that control its effectiveness in both technical and financial terms (e.g., Klose et al., 2014a). A large part of the complexity in assessing landslide risk as measured by economic costs is due to unique problems in understanding of (i) what types of landslide damage affect human activity and infrastructure in which way, (ii) how society contributes and responds to various kinds of damage, and (iii) how landslide damage is valued in monetary terms. Landslide economics shows the potential to take account of these sociocultural factors to the benefit of risk analysis (e.g., Klose et al., 2014b). The present contribution introduces local and regional case studies in which different economic issues of landslide risk are highlighted using the example of public infrastructures in NW Germany. A special focus is on the following topics: (i) risk culture and created risk, (ii

  11. Characteristics of deep-seated catastrophic landslide in a valley, movement process, and determination of deposition hazard area

    NASA Astrophysics Data System (ADS)

    Lo, Chia-Ming; Weng, Meng-Chia

    2013-04-01

    During extreme rainfall, deep-seated catastrophic landslide is a frequent mishap in main stream and tributaries of Taiwan. Reviewing the histories of Taiwan landslide events, as a large and deep-seated rock/soil mass of simultaneous movements in a valley, it might cause serious disasters. Reviewing the present literatures, there are morphological indications that the potential deep-seated catastrophic landslide can be track and find. Especially, the slate slope is influenced by weathering and gravitation for a long time, it become weak and it may cause the sliding slope creep and folding rock that will become the sliding surface of deep-seated catastrophic landslide. But analysis deep-seated catastrophic landslides for disaster preparedness and response planning are sometimes inadequate due to the complexity of such slopes. Whereas, this study mainly focus on deep-seated catastrophic landslide in valley. The study area has chosen Xiandushan Mountain, the 115.9 k of Suhua highway, and Zhuoshui River which to discuss the characteristics of deep-seated catastrophic landslide in a valley, movement process, and deposition hazard area. Base on the past events of deep-seated catastrophic landslide, the geological investigation, morphological analysis, and remote sensing technology will helpful to induce the geological characteristics and the morphological evolution. Besides, the deep-seated catastrophic landslide events will simplify to set up the physical modeling, its interpret the variation conditions to influence the characteristics, movement process, and deposition hazard area for deep-seated catastrophic landslide. The results of physical modeling were compared with those produced by numerical analysis (Application of discrete element method by PFC3D program) so that the correctness of the numerical simulation could be justified. Subsequently, calibrated numerical methods adopted in the small-scale model were used to simulate the full-scale model. The simulation

  12. Chromosome Conformation of Human Fibroblasts Grown in 3-Dimensional Spheroids

    PubMed Central

    Chen, Haiming; Comment, Nicholas; Chen, Jie; Ronquist, Scott; Hero, Alfred; Ried, Thomas; Rajapakse, Indika

    2015-01-01

    In the study of interphase chromosome organization, genome-wide chromosome conformation capture (Hi-C) maps are often generated using 2-dimensional (2D) monolayer cultures. These 2D cells have morphological deviations from cells that exist in 3-dimensional (3D) tissues in vivo, and may not maintain the same chromosome conformation. We used Hi-C maps to test the extent of differences in chromosome conformation between human fibroblasts grown in 2D cultures and those grown in 3D spheroids. Significant differences in chromosome conformation were found between 2D cells and those grown in spheroids. Intra-chromosomal interactions were generally increased in spheroid cells, with a few exceptions, while inter-chromosomal interactions were generally decreased. Overall, chromosomes located closer to the nuclear periphery had increased intra-chromosomal contacts in spheroid cells, while those located more centrally had decreased interactions. This study highlights the necessity to conduct studies on the topography of the interphase nucleus under conditions that mimic an in vivo environment. PMID:25738643

  13. Simple explanations for shallow landslides!?

    NASA Astrophysics Data System (ADS)

    Graf, Frank; Rickli, Christian

    2016-04-01

    In order to find easily recordable and practicable parameters for estimating the resistance of steep slopes against superficial soil failure, 218 comprehensively documented shallow landslides triggered in forested area have been analysed. The parameters investigated are divided into three principal subject areas: soil mechanics, vegetation, and topography. From the soil mechanical perspective, the shear parameters angle of internal friction Φ' and cohesion c' were pivotal. Information on them derived from field classification, laboratory analyses of grain size distribution (USCS) as well as from direct shear and triaxial compression tests with corresponding soil material. In respect of vegetation, forest aspects were of particular interest e.g. tree species composition, degree of coverage, layering, development stage, health, and gap size. Topographically, the focus was on terrain morphology, inclination, exposition, and altitude. It turned out that applying a three-step filter based on the aforementioned parameter categories yielded a retrospectively explanation power of 97% (n=212). The respective main criteria that were serially applied are: soil mechanics: slope inclination α is less than 5° steeper than the angle of internal friction Φ' of the corresponding soil material vegetation: forests are in a multi-layered or well structured pole or tree wood stage with a tree coverage degree of > 40% topography: the line of slope - transverse profile of the area of shallow landslide is NOT concave-flat, flat-concave, or convex-concave The application of the first step, the "5° -criterion", revealed that about 50% (n=107) of the slopes with the superficial soil failures were more than 5° steeper than the angle of internal friction Φ' of the soil material. In the second step, the vegetation-criteria explained another 40% (n=90) insofar that the corresponding requirements were not met. The topography step, finally, showed that additional 15 shallow landslides (7

  14. Thermo-Poro-Elastic Effects in Landslide Dynamics

    NASA Astrophysics Data System (ADS)

    Goren, L.; Aharonov, E.; Anders, M. H.

    2009-04-01

    friction reduction. A pore pressure- velocity phase plane is described, divided by a separatrix distinguishing between catastrophic and arrested sliding. Why landslide runout distances increase with increasing slide size? Natural landslides, like the Heart Mountain slide, often exhibit surprisingly large travel distances, and an unexplained decrease in apparent friction coefficient H/L (where H is the drop height and L the travel distance) with increasing slide volume, V. We suggest that the TPE mechanism operating at the base of landslides may explain this behavior: Depth-dependent permeability controls pore pressure diffusion rates from the shear-heating shear-zone, allowing larger slides to maintain high pore pressure for longer times, thus resulting in larger travel distances L and a lower H/L. The numerically obtained relation between V and H/L agrees with field data of subaerial landslides. The study is then implemented for predicting the motion of Heart Mt landslide.

  15. Earthquake induced landslide hazard field observatory in the Avcilar peninsula

    NASA Astrophysics Data System (ADS)

    Bigarre, Pascal; Coccia, Stella; Theoleyre, Fiona; Ergintav, Semih; Özel, Oguz; Yalçinkaya, Esref; Lenti, Luca; Martino, Salvatore; Gamba, Paolo; Zucca, Francesco; Moro, Marco

    2015-04-01

    SAR temporal series has been undertaken, providing global but accurate Identification and characterization of gravitational phenomena covering the aera. Evaluation of the resolution and identification of landslide hazard-related features using space multispectral/hyperspectral image data has been realized. Profit has been gained from a vast drilling and geological - geotechnical survey program undertaken by the Istanbul Metropolitan Area, to get important data to complete the geological model of the landslide as well as one deep borehole to set up permanent instrumentation on a quite large slow landslide, fully encircled by a dense building environment. The selected landslide was instrumented in 2014 with a real-time observational system including GPS, rainfall, piezometer and seismic monitoring. Objective of this permanent monitoring system is three folds: first to detect and quantify interaction between seismic motion, rainfall and mass movement, building a database opened to the scientific community in the future, second to help to calibrate dynamic numerical geomechanical simulations intending to study the sensitivity to seismic loading, and last but not least. Last but not least important geophysical field work has been conducted to assess seismic site effects already noticed during the 1999 earthquake .Data, metadata and main results are from now progressively compiled and formatted for appropriate integration in the cloud monitoring infrastructure for data sharing.

  16. A comprehensive database of Martian landslides

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    During a long-term project, we have identified and classified a large number (> 3000) of Martian landslides especially but not exclusively from Valles Marineris. This database provides a more complete basis for a statistical study of landslides on Mars and its relationship with geographical and environmental conditions. Landslides have been mapped according to standard geomorphological criteria, delineating both the landslide scar and accumulation limits, associating each scarp to a deposit, and using the program ArcGis for generation of a complete digital dataset. Multiple accumulations from the same source area or from different sources have been differentiated, where possible, to obtain a more complete dataset and to allow more refined analyses. Each landslide has been classified according to a set of criteria including: type, degree of confinement, possible trigger, elevation with respect to datum, geomorphological features, degree of multiplicity, and so on. The runout, fall height, and volume have been measured for each deposit. In fact, the database is revealing a series of trends that may assist at understanding landform processes on Mars and its past climatic conditions. One of the most interesting aspects of our dataset is the presence of a population of landslides whose particularly long mobility deviates from average behavior. While some landslides have travelled unimpeded on a usually flat area, others have travelled against obstacles or mounds. Therefore, landslides are also studied in relation to i) morphologies created by the landslide itself, ii) presence of mounds, barriers or elevations than have affected the movement of the landslide mass. In some extreme cases, the landslide was capable of travelling for several tens of km along the whole valley and upon reaching the opposite side it travelled upslope for several hundreds of meters, which is indication of high travelling speed. In other cases, the high speed is revealed by dynamic deformations

  17. Submarine Landslides at Santa Catalina Island, California

    NASA Astrophysics Data System (ADS)

    Legg, M. R.; Francis, R. D.

    2011-12-01

    Santa Catalina Island is an active tectonic block of volcanic and metamorphic rocks originally exposed during middle Miocene transtension along the evolving Pacific-North America transform plate boundary. Post-Miocene transpression created the existing large pop-up structure along the major strike-slip restraining bend of the Catalina fault that forms the southwest flank of the uplift. Prominent submerged marine terraces apparent in high-resolution bathymetric maps interrupt the steep submarine slopes in the upper ~400 meters subsea depths. Steep subaerial slopes of the island are covered by Quaternary landslides, especially at the sea cliffs and in the blueschist metamorphic rocks. The submarine slopes also show numerous landslides that range in area from a few hectares to more than three sq-km (300 hectares). Three or more landslides of recent origin exist between the nearshore and first submerged terrace along the north-facing shelf of the island's West End. One of these slides occurred during September 2005 when divers observed a remarkable change in the seafloor configuration after previous dives in the area. Near a sunken yacht at about 45-ft depth where the bottom had sloped gently into deeper water, a "sinkhole" had formed that dropped steeply to 100-ft or greater depths. Some bubbling sand was observed in the shallow water areas that may be related to the landslide process. High-resolution multibeam bathymetry acquired in 2008 by CSU Monterey Bay show this "fresh" slide and at least two other slides of varying age along the West End. The slides are each roughly 2 hectares in area and their debris aprons are spread across the first terrace at about 85-m water depth that is likely associated with the Last Glacial Maximum sealevel lowstand. Larger submarine slides exist along the steep Catalina and Catalina Ridge escarpments along the southwest flank of the island platform. A prominent slide block, exceeding 3 sq-km in area, appears to have slipped more than

  18. Analyzing Geometric Characteristics of Rainfall-induced Landslides

    NASA Astrophysics Data System (ADS)

    Chiang, S. H.; Chen, C. F.

    2015-12-01

    Previous landslide prediction studies have focused on the assessment of location of landslides. Besides location, landslide geometric features (i.e., size and shape) are important factors that influence the distribution and dynamics of landslides. Statistical methods have been used to determine the frequency-size or frequency-volume relationships of landslides, through examining landslide inventories. However, the question of what sets their size and shape is unanswered. In this study, a landslide geometry generating algorithm (LsGA) is developed for quantifying landslide geometric features, including area, perimeter, upper length, lower length, average length and average width, with incorporating an existing landslide inventory and digital elevation model (DEM). The Kaoping watershed in Southern Taiwan is selected as the study area, and the landslide inventory prepared after Typhoon Morakot (August 2009) were applied for LsGA analysis. Landslide geometric features generated by LsGA were then used to correlate to geo-environmental factors, such as slope, contributing area and topographic index (TI), in a logistic regression model. Preliminary findings are: (1) smaller landslides are generally longer than larger landslides, (2) the upper length of small landslides is relatively wider than large landslides, (3) small landslides are more likely to be observed over gentle slopes (<30 deg), and (4) small landslides are more likely to be observed over lower part of slopes (high TI value, near channels). Other results will be presented in the meeting.

  19. Comparing The Results Of Terrasar-X And Envisat Sar Images With Ps-InSAR Methods On Slow Motion Landslides: Koyulhisar, Turkey

    NASA Astrophysics Data System (ADS)

    Demirel, Mehmet; Poyraz, Fatih; Özgür Hastaoğlu, Kemal; Türk, Tarık; Tatar, Orhan; Birdal, Anıl Can

    2015-04-01

    In recent years, PS-InSAR method has been used widely on monitoring slow motion landslides. The motion amounts obtained by PS-InSAR method is avaliable only in LOS(line of sight) and it can't provide information about three dimensional motions. Nevertheless, motions caused by landslides are usually 3 dimensional and also they are not homogeneous. This is one of the biggest handicaps of monitoring landslides with SAR method. In this study, annual motion rates of the PS points that are located in Koyulhisar landslide region are obtained from differently resolutioned sar images of Envisat and Terrasar-x satellite's frames through PS-InSAR method and by using StaMPS software. Throughout the landslide region a profile has been established in North-South line, and the correlation of the results obtained from the sar images lining on this profile. All results are observed to have %80 correlation with each other. By means of these results a subsidence area has been found in the northern region and an uplifting area has been found in the southern region. Through this study, general information about the landslide mechanism has been obtained.

  20. Geological factors contributing to landslides: case studies of a few landslides in different regions of India

    NASA Astrophysics Data System (ADS)

    Vasudevan, Nirmala; Ramanathan, Kaushik

    2016-02-01

    Landslides - mass movements of rock, debris or earth down a slope - are worldwide phenomena which cause significant damage and an estimated 5000 fatalities each year. They are caused by the interplay of various natural and anthropogenic factors and occur under diverse geoenvironmental conditions. In India, landslides occur primarily in the Himalayas of North India and in the Western Ghats of South India. This paper reports the results of field investigations for six landslide sites in North, Northeast and South India. We provide explanations as to why several landslides occurred at each of the sites. Our goal is to gain a deeper insight into the causes and precursors of landslides, which will facilitate more accurate identification of landslide-prone locations and enable early detection of landslide events.

  1. Comment on "The reduction of friction in long-runout landslides as an emergent phenomenon" by Brandon C. Johnson, Charles S. Campbell, and H. Jay Melosh

    NASA Astrophysics Data System (ADS)

    Louge, M. Y.

    2016-05-01

    Johnson et al. (2016) use numerical simulations of disks to revisit the mystery of the struzstrom, a kind of landslide that travels an unexpectedly long distance on flat land, far beyond the mountain slope on which it initially accelerated.

  2. Giant blocks in the South Kona landslide, Hawaii

    USGS Publications Warehouse

    Moore, J.G.; Bryan, W.B.; Beeson, M.H.; Normark, W.R.

    1995-01-01

    A large field of blocky sea-floor hills, up to 10km long and 500 high, are gigantic slide blocks derived from the west flank of Mauna Loa volcano on the island of Hawaii. These megablocks are embedded in the toe of the south Kona landslide, which extends ~80km seaward from the present coastline to depths of nearly 5km. A 10-15km-wide belt of numerous, smaller, 1-3 km-long slide blocks separates the area of giant blocks from two submarine benches at depths of 2600 and 3700m depth that terminate seaward 20 to 30km from the shoreline. Similar giant blocks are found on several other major submarine Hawaiian landslides, including those north of Oahu and Molokai, but the South Kona blocks are the first to be examined in detail using high-resolution bathymetry, dredging, and submersible diving. Dredging of two of the giant blocks brought up pillowed tholeiitic lava. Megablocks were carried by a late Pleistocene giant landslide 40-80km west from the ancestral shoreline of Mauna Loa volcano before growth of the midslope benches by later slump movement. -from Authors

  3. Long runout landslides: a solution from granular mechanics

    NASA Astrophysics Data System (ADS)

    Parez, Stanislav; Aharonov, Einat

    2015-10-01

    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.

  4. Modelling the landslide area and sediment discharge in landslide-dominated region, Taiwan

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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

  5. Seasonal landslide mapping and estimation of landslide mobilization rates using aerial and satellite images

    NASA Astrophysics Data System (ADS)

    Fiorucci, F.; Cardinali, M.; Carlà, R.; Rossi, M.; Mondini, A. C.; Santurri, L.; Ardizzone, F.; Guzzetti, F.

    2011-06-01

    We tested the possibility of using digital, color aerial ortho-photographs and monoscopic, panchromatic satellite images of comparable spatial and radiometric resolution, to map recent landslides in Italy and to update existing measures of landslide mobilization. In a 90-km 2 area in Umbria, central Apennines, rainfall resulted in abundant landslides in the period from September 2004 to June 2005. Analysis of the rainfall record determined the approximate dates of landslide occurrence and revealed that the slope failures occurred in response to moderately wet rainfall periods. The slope failures occurred primarily in cultivated terrain and left subtle morphological and land cover signatures, making the recognition and mapping of the individual landslides problematic. Despite the difficulty with the identification of the landslides without the use of stereoscopic visualization, visual analysis of the aerial and satellite images allowed mapping 457 new landslides, ranging in area 3.0 × 10 1 < AL < 2.5 × 10 4 m 2, for a total landslide area ALT = 6.92 × 10 5 m 2. To identify the landslides, the investigators adopted the interpretation criteria commonly used to identify and map landslides on aerial photography. The result confirms that monoscopic, very high resolution images taken by airborne and satellite sensors can be used to prepare landslide maps even where slope failures are difficult to detect, provided the imagery has sufficient geometric and radiometric resolutions. The different dates of the aerial (March 2005) and the satellite (June-July 2005) images allowed the temporal segmentation of the landslide information, and studying the statistics of landslide area and volume for different periods. Compared to pre-existing information on the abundance and size of the landslides in the area, the inventory obtained by studying the aerial and satellite images proved more complete. The new mapping showed 145% more landslides and 85% more landslide area than a pre

  6. Evidences of landslide earthquake triggering due to self-excitation process

    NASA Astrophysics Data System (ADS)

    Bozzano, F.; Lenti, L.; Martino, Salvatore; Paciello, A.; Scarascia Mugnozza, G.

    2011-06-01

    The basin-like setting of stiff bedrock combined with pre-existing landslide masses can contribute to seismic amplifications in a wide frequency range (0-10 Hz) and induce a self-excitation process responsible for earthquake-triggered landsliding. Here, the self-excitation process is proposed to justify the far-field seismic trigger of the Cerda landslide (Sicily, Italy) which was reactivated by the 6th September 2002 Palermo earthquake ( M s = 5.4), about 50 km far from the epicentre. The landslide caused damage to farm houses, roads and aqueducts, close to the village of Cerda, and involved about 40 × 106 m3 of clay shales; the first ground cracks due to the landslide movement formed about 30 min after the main shock. A stress-strain dynamic numerical modelling, performed by FDM code FLAC 5.0, supports the notion that the combination of local geological setting and earthquake frequency content played a fundamental role in the landslide reactivation. Since accelerometric records of the triggering event are not available, dynamic equivalent inputs have been used for the numerical modelling. These inputs can be regarded as representative for the local ground shaking, having a PGA value up to 0.2 m/s2, which is the maximum expected in 475 years, according to the Italian seismic hazard maps. A 2D numerical modelling of the seismic wave propagation in the Cerda landslide area was also performed; it pointed out amplification effects due to both the structural setting of the stiff bedrock (at about 1 Hz) and the pre-existing landslide mass (in the range 3-6 Hz). The frequency peaks of the resulting amplification functions ( A( f)) fit well the H/ V spectral ratios from ambient noise and the H/ H spectral ratios to a reference station from earthquake records, obtained by in situ velocimetric measurements. Moreover, the Fourier spectra of earthquake accelerometric records, whose source and magnitude are consistent with the triggering event, show a main peak at about 1 Hz

  7. Landslides in the New Madrid seismic zone

    SciTech Connect

    Jibson, R.W.; Keefer, D.K.

    1985-01-01

    During the New Madrid earthquakes of 1811-12, bluffs bordering the Mississippi alluvial plain in the epicentral region underwent large-scale landsliding. Between Cairo, Illinois and Memphis, Tennessee, the authors mapped 221 large landslides of three types: (1) old, eroded, coherent block slides and slumps; (2) old earth flows; and (3) young, fresh slumps that occur only along near-river bluffs and are the only landslides present along such bluffs. Historical accounts and field evidence indicate that most or all old coherent slides and earth flows date to the 1811-12 earthquakes and that the only currently active, large-scale landsliding in the area occurs along bluffs bordering the river. Analysis of old coherent slides and earth flows indicates that landslide distribution is most strongly affected by slope height, but that proximity to the hypocenters of the 1811-12 earthquakes also has a significant effect. Slope-stability analyses of an old coherent slide and an earth flow selected as representative of the principal kinds of landslides present indicate that both were stable in aseismic conditions even when water tables were at highest possible levels. However, a dynamic Newmark displacement analysis shows that ground shaking such as that in 1811-12 would cause large displacements leading to catastrophic failure in both slides. These results indicate that in large earthquakes landsliding in much of the study are is likely. Moderate earthquakes may also trigger landslides at some locations.

  8. UAV for landslide mapping and deformation analysis

    NASA Astrophysics Data System (ADS)

    Shi, Beiqi; Liu, Chun

    2015-12-01

    Unmanned aerial vehicle (UAV) can be a flexible, cost-effective, and accurate method to monitor landslides with high resolution aerial images. Images acquired on 05 May 2013 and 13 December 2014 of the Xishan landslide, China, have been used to produce a high-resolution ortho-mosaic of the entire landslide and digital elevation model (DEM). The UAV capability for imaging detection and displacements on the landslide surface has been evaluated, and the subsequent image processing approaches for suitably georectifying the data have been assessed. Objects derived from the segmentation of a multispectral image were used as classifying units for landslide object-oriented analysis. Spectral information together with various morphometric characteristics was applied for recognizing landslides from false positives. Digital image correlation technique was evaluated to quantify and map terrain displacements. The magnitude and direction of the displacement vectors derived from correlating two temporal UAV images corresponded to a visual interpretation of landslide change. Therefore, the UAV can demonstrate its capability for producing valuable landslide mapping data and deformation information.

  9. The 3-dimensional construction of the Rae craton, central Canada

    NASA Astrophysics Data System (ADS)

    Snyder, David B.; Craven, James A.; Pilkington, Mark; Hillier, Michael J.

    2015-10-01

    Reconstruction of the 3-dimensional tectonic assembly of early continents, first as Archean cratons and then Proterozoic shields, remains poorly understood. In this paper, all readily available geophysical and geochemical data are assembled in a 3-D model with the most accurate bedrock geology in order to understand better the geometry of major structures within the Rae craton of central Canada. Analysis of geophysical observations of gravity and seismic wave speed variations revealed several lithospheric-scale discontinuities in physical properties. Where these discontinuities project upward to correlate with mapped upper crustal geological structures, the discontinuities can be interpreted as shear zones. Radiometric dating of xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences. These ages can also be correlated to surface rocks. The 3.6-2.6 Ga Rae craton comprises at least three smaller continental terranes, which "cratonized" during a granitic bloom. Cratonization probably represents final differentiation of early crust into a relatively homogeneous, uniformly thin (35-42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho. The peak thermotectonic event at 1.86-1.7 Ga was associated with the Hudsonian orogeny that assembled several cratons and lesser continental blocks into the Canadian Shield using a number of southeast-dipping megathrusts. This orogeny metasomatized, mineralized, and recrystallized mantle and lower crustal rocks, apparently making them more conductive by introducing or concentrating sulfides or graphite. Little evidence exists of thin slabs similar to modern oceanic lithosphere in this Precambrian construction history whereas underthrusting and wedging of continental lithosphere is inferred from multiple dipping discontinuities.

  10. A 3-Dimensional Anatomic Study of the Distal Biceps Tendon

    PubMed Central

    Walton, Christine; Li, Zhi; Pennings, Amanda; Agur, Anne; Elmaraghy, Amr

    2015-01-01

    Background Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature. Purpose To comprehensively describe the morphology of the distal biceps tendon. Study Design Descriptive laboratory study. Methods The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling. Results The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads. Conclusion This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics. Clinical Relevance A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation. PMID:26665092

  11. Development and Validation of a 3-Dimensional CFB Furnace Model

    NASA Astrophysics Data System (ADS)

    Vepsäläinen, Arl; Myöhänen, Karl; Hyppäneni, Timo; Leino, Timo; Tourunen, Antti

    At Foster Wheeler, a three-dimensional CFB furnace model is essential part of knowledge development of CFB furnace process regarding solid mixing, combustion, emission formation and heat transfer. Results of laboratory and pilot scale phenomenon research are utilized in development of sub-models. Analyses of field-test results in industrial-scale CFB boilers including furnace profile measurements are simultaneously carried out with development of 3-dimensional process modeling, which provides a chain of knowledge that is utilized as feedback for phenomenon research. Knowledge gathered by model validation studies and up-to-date parameter databases are utilized in performance prediction and design development of CFB boiler furnaces. This paper reports recent development steps related to modeling of combustion and formation of char and volatiles of various fuel types in CFB conditions. Also a new model for predicting the formation of nitrogen oxides is presented. Validation of mixing and combustion parameters for solids and gases are based on test balances at several large-scale CFB boilers combusting coal, peat and bio-fuels. Field-tests including lateral and vertical furnace profile measurements and characterization of solid materials provides a window for characterization of fuel specific mixing and combustion behavior in CFB furnace at different loads and operation conditions. Measured horizontal gas profiles are projection of balance between fuel mixing and reactions at lower part of furnace and are used together with both lateral temperature profiles at bed and upper parts of furnace for determination of solid mixing and combustion model parameters. Modeling of char and volatile based formation of NO profiles is followed by analysis of oxidizing and reducing regions formed due lower furnace design and mixing characteristics of fuel and combustion airs effecting to formation ofNO furnace profile by reduction and volatile-nitrogen reactions. This paper presents

  12. Simple scaling of catastrophic landslide dynamics.

    PubMed

    Ekström, Göran; Stark, Colin P

    2013-03-22

    Catastrophic landslides involve the acceleration and deceleration of millions of tons of rock and debris in response to the forces of gravity and dissipation. Their unpredictability and frequent location in remote areas have made observations of their dynamics rare. Through real-time detection and inverse modeling of teleseismic data, we show that landslide dynamics are primarily determined by the length scale of the source mass. When combined with geometric constraints from satellite imagery, the seismically determined landslide force histories yield estimates of landslide duration, momenta, potential energy loss, mass, and runout trajectory. Measurements of these dynamical properties for 29 teleseismogenic landslides are consistent with a simple acceleration model in which height drop and rupture depth scale with the length of the failing slope. PMID:23520108

  13. Exploring model sensitivity issues across different scales in landslide susceptibility

    NASA Astrophysics Data System (ADS)

    Catani, F.; Lagomarsino, D.; Segoni, S.; Tofani, V.

    2013-03-01

    Despite the large number of recent advances and developments in landslide susceptibility mapping there is still a lack of studies focusing on specific aspects of LSM model sensitivity. For example, the influence of factors of paramount importance such as the survey scale of the landslide conditioning variables (LCVs), the resolution of the mapping unit (MUR) and the optimal number and ranking of LCVs have never been investigated analytically, especially on large datasets. In this paper we attempt this experimentation concentrating on the impact of model tuning choice on the final result, rather than on the comparison of methodologies. To this end, we adopt a simple implementation of the random forest (RF) classification family to produce an ensemble of landslide susceptibility maps for a set of different model settings, input data types and scales. Random forest is a combination of tree (usually binary) bayesian predictors that permits to relate a set of contributing factors with the actual landslides occurrence. Being it a nonparametric model, it is possible to incorporate a range of numeric or categorical data layers and there is no need to select unimodal training data. Many classical and widely acknowledged landslide predisposing factors have been taken into account as mainly related to: the lithology, the land use, the land surface geometry (derived from of DTM), the structural and anthropogenic constrains. In addition, for each factor we also included in the parameter set the standard deviation (for numerical variables) or the variety (for categorical ones). The use of random forest enables to estimate the relative importance of the single input parameters and to select the optimal configuration of the regression model. The model was initially applied using the complete set of input parameters then, with progressively smaller subsamples of the parameter space. Considering the best set of parameters we also studies the impact of scale and accuracy of input

  14. Sensitivity analysis and scale issues in landslide susceptibility mapping

    NASA Astrophysics Data System (ADS)

    Catani, Filippo; Lagomarsino, Daniela; Segoni, Samuele; Tofani, Veronica

    2013-04-01

    Despite the large number of recent advances and developments in landslide susceptibility mapping (LSM) there is still a lack of studies focusing on specific aspects of LSM model sensitivity. For example, the influence of factors of paramount importance such as the survey scale of the landslide conditioning variables (LCVs), the resolution of the mapping unit (MUR) and the optimal number and ranking of LCVs have never been investigated analytically, especially on large datasets. In this paper we attempt this experimentation concentrating on the impact of model tuning choice on the final result, rather than on the comparison of methodologies. To this end, we adopt a simple implementation of the random forest (RF) classification family to produce an ensamble of landslide susceptibility maps for a set of different model settings, input data types and scales. RF classification and regression methods offer a very flexible environment for testing model parameters and mapping hypotheses, allowing for a direct quantification of variable importance. The model choice is, in itself, quite innovative since it is the first time that such technique, widely used in remote sensing for image classification, is used in this form for the production of a LSM. Random forest is a combination of tree (usually binary) bayesian predictors that permits to relate a set of contributing factors with the actual landslides occurrence. Being it a nonparametric model, it is possible to incorporate a range of numeric or categorical data layers and there is no need to select unimodal training data. Many classical and widely acknowledged landslide predisposing factors have been taken into account as mainly related to: the lithology, the land use, the land surface geometry (derived from DTM), the structural and anthropogenic constrains. In addition, for each factor we also included in the parameter set the standard deviation (for numerical variables) or the variety (for categorical ones). The use of

  15. Rainfall characteristics associated to the triggering of fast- and slow-moving landslides - a comparison between the South French Alps and Lower Austria

    NASA Astrophysics Data System (ADS)

    Remaitre, Alexandre; Wallner, Stefan; Promper, Catrin; Glade, Thomas; Malet, Jean-Philippe

    2013-04-01

    Rainfall is worldwide a recognized trigger of landslides. Numerous studies were conducted in order to define the relationships between the precipitations and the triggering or the reactivation of landslides. Hydrological triggering of landslides can be divided in three general types: (1) development of local perched water tables in the subsoil leading to shallow slope instabilities and possible gravitational flows, (2) long-lasting rise in permanent water tables leading to more deep-seated slope instabilities, and (3) intense runoff causing channel-bed erosion and debris flows. Types (1) and (3) are usually observed during high rainfall intensities (hourly and daily rainfall) associated to heavy storms; type (2) is usually observed through increasing water content in the subsoil due to antecedent rainfalls (weekly or monthly rainfall) and/or massive snowmelt. Many investigations have been carried out to determine the amount of precipitation needed to trigger slopes failures. For rainfall-induced landslides a threshold may be define the rainfall, soil moisture or hydrological conditions that, when reached or exceeded, are likely to trigger landslides. Usually rainfall thresholds can be defined on physical process-based or conceptual models or empirical, historical and statistical bases. Nevertheless, both the large variety of landslides and to the extreme variety of climatic conditions leading to the triggering or the reactivation of a landslide lead to a regional definition of relationships between landslide occurrence and associated climatic conditions. The purpose of this case study is to analyze the relationships between the triggering of three types of landslides, debris flows, shallow landslides and deep-seated mudslides, and different patterns of rainfall in two study sites with different physiographic and climatic characteristics: the Barcelonnette basin in the South French Alps and the Waidhofen an der Ybbs area in Lower Austria. For this purpose, we

  16. Landslides risk mitigation along lifelines

    NASA Astrophysics Data System (ADS)

    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.

    2012-04-01

    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

  17. A preliminary regional assessment of earthquake-induced landslide susceptibility for Vrancea Seismic Region

    NASA Astrophysics Data System (ADS)

    Micu, Mihai; Balteanu, Dan; Ionescu, Constantin; Havenith, Hans; Radulian, Mircea; van Westen, Cees; Damen, Michiel; Jurchescu, Marta

    2015-04-01

    In seismically-active regions, earthquakes may trigger landslides enhancing the short-to-long term slope denudation and sediment delivery and conditioning the general landscape evolution. Co-seismic slope failures present in general a low frequency - high magnitude pattern which should be addressed accordingly by landslide hazard assessment, with respect to the generally more frequent precipitation-triggered landslides. The Vrancea Seismic Region, corresponding to the curvature sector of the Eastern Romanian Carpathians, represents the most active sub-crustal (focal depth > 50 km) earthquake province of Europe. It represents the main seismic energy source throughout Romania with significant transboundary effects recorded as far as Ukraine and Bulgaria. During the last 300 years, the region featured 14 earthquakes with M>7, among which seven events with magnitude above 7.5 and three between 7.7 and 7.9. Apart from the direct damages, the Vrancea earthquakes are also responsible for causing numerous other geohazards, such as ground fracturing, groundwater level disturbances and possible deep-seated landslide occurrences (rock slumps, rock-block slides, rock falls, rock avalanches). The older deep-seated landslides (assumed to have been) triggered by earthquakes usually affect the entire slope profile. They often formed landslide dams strongly influencing the river morphology and representing potential threats (through flash-floods) in case of lake outburst. Despite the large potential of this research issue, the correlation between the region's seismotectonic context and landslide predisposing factors has not yet been entirely understood. Presently, there is a lack of information provided by the geohazards databases of Vrancea that does not allow us to outline the seismic influence on the triggering of slope failures in this region. We only know that the morphology of numerous large, deep-seated and dormant landslides (which can possibly be reactivated in future

  18. Real-time Global Flood and Landslide Prediction Using Satellite Observations (Invited)

    NASA Astrophysics Data System (ADS)

    Adler, R. F.; Yilmaz, K. K.; Kirschbaum, D.; Hong, Y.; Pierce, H.; Policelli, F.

    2009-12-01

    A global flood and landslide detection/prediction system is now running in real-time using multi-satellite rainfall analysis in combination with hydrological models and algorithms to estimate flood and landslide locations (http://trmm.gsfc.nasa.gov/publications_dir/potential_flood_hydro.html). The system also uses satellite-based land surface information such as digital elevation information from the NASA SRTM (Shuttle Radar Terrain Mission) and vegetation information from MODIS in the model and algorithm calculations. Progress in using the TRMM Multi-satellite Precipitation Analysis (TMPA) as input to these flood and landslide forecasts is outlined, with case studies as well as validation in terms of flood/landslide events. Examples shown include the August 2009 landslide events in Taiwan and the major flood in Burma in spring of 2008. The flood determination algorithm consists of three major components: 1) multi-satellite precipitation estimation; 2) characterization of land surface including digital elevation information and other surface information, topography-derived hydrologic parameters such as flow direction, flow accumulation, river network and basin boundaries, etc.; 3) a hydrological model to infiltrate rainfall and route overland runoff. Results of calculated water depth over a threshold are then displayed about six hours after real-time. Time-history of inundations are also calculated and displayed. Validation analysis indicates good results for flood detection and evolution, but with limitations in the current routing calculations. Occasional flood events are missed due to limitations in the satellite rain estimations. An improved global hydrological model is being tested and initial improved results will be shown. Global numerical weather prediction rainfall forecasts are also being used experimentally to extend the period of utility of the flood information. In terms of landslides, the satellite rainfall information is combined with a global

  19. Coseismic landslides associated with the 2015 Gorkha earthquake sequence in Nepal

    NASA Astrophysics Data System (ADS)

    Clark, M. K.; Gallen, S. F.; West, A. J.; Chamlagain, D.; Roback, K.; Lowe, K.; Niemi, N. A.; Greenwood, W.; Bateman, J.; Zekkos, D.

    2015-12-01

    Coseismic landsliding due to the M7.8 Gorkha earthquake sequence poses immediate and prolonged hazards to communities in the Nepalese Himalaya, as well as a rare opportunity to study the effect of large earthquakes on erosion and sediment budgets in mountain belts. We present near-real time response models developed within hours of the event using a simplified Newmark analysis. These rapid response models were used to prioritize early scientific efforts and to guide rescue and recovery efforts by US and international agencies. Analyses included prediction of regional landslide occurrence and identification of potential landslide dam locations, which could cause flooding upstream and downstream if the dam is catastrophically breached. Subsequent investigations have included mapping of coseismic landslides using pre- and post- event satellite imagery and field observations, and inversion of mapped landslide distributions for estimates of near-surface rock strength. Compared to model predictions using regionally uniform rock strength, observed landslides are more concentrated north of the physiographic transition between the Lesser and Greater Himalaya where hillslope gradients suddenly steepen. Fewer landslides than predicted occurred in the high elevation, steep glaciated terrain and in areas of highest modeled PGA, just to the south of this physiographic transition. Discrepancies between model predictions and observations could arise from spatial variability in rock strength, in PGA or frequency content at specific site locations, or by pre-conditioning (topographic or otherwise) for landslide hazard. Co-seismic landsliding produces a prolonged hazard for years to come. In the near term, more frequent landslides are expected to occur during the summer monsoon seasons by remobilization of debris and due to a dynamic increase in pore-pressure on hillsides or near ridge tops that were pervasively cracked during the main earthquake or aftershocks, but did not

  20. Landslides on Earth, Mars, Moon and Mercury

    NASA Astrophysics Data System (ADS)

    Brunetti, Maria Teresa; Xiao, Zhiyong; Komatsu, Goro; Peruccacci, Silvia; Fiorucci, Federica; Cardinali, Mauro; Santangelo, Michele; Guzzetti, Fausto

    2015-04-01

    Landslides play an important role in the evolution of landscapes on Earth and on other solid planets of the Solar System. On Earth, landslides have been recognized in all continents, and in subaerial and submarine environments. The spatial and temporal range of the observed slope failures is extremely large on Earth. Surface gravity is the main factor driving landslides in solid planets. Comparison of landslide characteristics, e.g. the landslide types and sizes (area, volume, fall height, length) on various planetary bodies may help in understanding the effect of surface gravity on failure initiation and propagation. In the last decades, planetary exploration missions have delivered an increasing amount of high-resolution imagery, which enables to resolve and identify morphologic structures on planetary surfaces in great detail. Here, we present three geomorphological inventories of extraterrestrial landslides on Mars, Moon and Mercury. To recognize and map the landslides on the three Solar System bodies, we adopt the same visual criteria commonly used by geomorphologists to identify terrestrial slope failures in aerial photographs or satellite images. Landslides are classified based on the morphological similarity with terrestrial ones. In particular, we focus on rock slides mapped in Valles Marineris, Mars, and along the internal walls of impact craters on the Moon and Mercury. We exploit the three inventories to study the statistical distributions of the failure sizes (e.g., area, volume, fall height, length), and we compare the results with similar distributions obtained for terrestrial landslides. We obtain indications on the effect of the different surface gravity on landslides on Earth and Mars through the relationship between the landslide area and volume on the two planets. From the analysis of the area, we hypothesize that the lack of medium size landslides on Mars is due to the absence of erosive processes, which are induced on Earth chiefly by water

  1. A 3-dimensional mass conserving element for compressible flows

    NASA Technical Reports Server (NTRS)

    Fix, G.; Suri, M.

    1985-01-01

    A variety of finite element schemes has been used in the numerical approximation of compressible flows particularly in underwater acoustics. In many instances instabilities have been generated due to the lack of mass conservation. Two- and three-dimensional elements are developed which avoid these problems.

  2. 3-Dimensional modeling of protein structures distinguishes closely related phytoplasmas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoplasmas (formerly mycoplasmalike organisms, MLOs) are cell wall-less bacteria that inhabit phloem tissue of plants and are transmitted from plant-to-plant by phloem-feeding insects. Numerous diseases affecting hundreds of plant species in many botanical families are attributed to infections by...

  3. InSAR imagery pattern matching validation for landslide assessment

    NASA Astrophysics Data System (ADS)

    Serbulea, Manole-Stelian; Gogu, Radu; Teleaga, Delia; Marcel Manoli, Daniel; Priceputu, Adrian; Gaitanaru, Dragos Stefan; Ungureanu, Constantin; Anghel, Alexandra; Andronic, Adrian; Niculescu, Alexandru; Liviu Bugea, Adrian

    2013-04-01

    The need for identifying over large areas ongoing instability phenomena and spotting the old ones pushed the boundaries of geotechnical engineering from numerical modeling and point-wise in-situ measurements towards geodesic and geographic sciences. Regardless of the ground-based monitoring techniques' precision and reliability, a larger scale monitoring is often useful to either better correlate the scattered results or to identify additional monitoring points. Using aerial ortho-photogrammetry and site visit recognition represent a good, yet costly method to obtain qualitative information about old inactive landslides. A more suitable approach is using ground-based or satellite radar interferometry (InSAR). The obvious disadvantage of the ground-based system is that the monitoring has to be carried out on a predetermined site while the space-borne system may be set to collect information from various sites in range by each successive passing. The quantitative results acquired through the means of InSAR provide a precise set of information regarding the soil surface displacement, with high accuracy and reliability. They provide a great means of identifying danger zones as well as a way of calibrating and augmenting the classical monitoring techniques. This work describes the possibility of integrating the InSAR measurements with the ground monitoring techniques to identify landslide occurrence hazard and reveal the whole of affected areas even when minute symptoms develop. One of the objectives is to propose InSAR monitoring as a fast and efficient mapping tool to help authorities minimize the damage produced by landslides. It can also provide engineers and scientists additional information to further study landslides dynamics phenomena (such as propagation). Interferometry on SAR data uses phase values from two radar images. When a point changes position, the distance between it and the sensor alters, modifying the phase of the signal. This change is used to

  4. Precipitation and soil accumulation history modifies future landslide hazard

    NASA Astrophysics Data System (ADS)

    Parker, R.; Hales, T. C.; Mudd, S. M.; Grieve, S. W. D.

    2015-12-01

    Landslides are a major global geohazard that are predicted to increase as anthropogenic climate change drives an increase in landslide-triggering storms. Humid mountains may be particularly important, as rainfall-induced shallow landsliding causes a significant proportion of global landslide fatalities. While precipitation is a significant driving force, future landslide susceptibility also depends on millennial-scale landslide history that limits the distribution of potential landslide material. However, the influence of landslide history on current and future landslide hazard is poorly understood. We address this problem by first quantifying the distribution of shallow landslide potential across 1347 km2 of the southern Appalachian Mountains using an unprecedented empirical dataset of hillslope soil depths and strength parameters. By accounting for landslide history, estimates of future landslide potential are lowered significantly. Slope stability modelling demonstrates that under current conditions, only 38% of potential landslide sites across the landscape could fail, regardless of the size of the storm. Of susceptible slopes, most can only fail during the largest possible precipitation events. This is because once a landslide occurs it takes thousands of years to accumulate enough soil to make a site unstable during precipitation. In contrast, the return period of large storms is tens to hundreds of years. This result challenges whether increases in precipitation predicted by climate models will lead to measureable increases in landslide frequency. Next, we examine how the distribution of potential landslide material changes through time as storm-induced landslides periodically remove material, using a coupled hillslope stability and soil accumulation model applied to the Appalachian landscape. Our results reveal the spatial pattern of temporal variability in landslide potential, which represents a neglected source of uncertainty when assessing regional

  5. A 3-dimensional Analysis of the Cassiopeia A Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Isensee, Karl

    We present a multi-wavelength study of the nearby supernova remnant Cassiopeia A (Cas A). Easily resolvable supernova remnants such as Cas A provide a unique opportunity to test supernova explosion models. Additionally, we can observe key processes in the interstellar medium as the ejecta from the initial explosion encounter Cas A's powerful shocks. In order to accomplish these science goals, we used the Spitzer Space Telescope's Infrared Spectrograph to create a high resolution spectral map of select regions of Cas A, allowing us to make a Doppler reconstruction of its 3-dimensional structure structure. In the center of the remnant, we find relatively pristine ejecta that have not yet reached Cas A's reverse shock or interacted with the circumstellar environment. We observe O, Si, and S emission. These ejecta can form both sheet-like structures as well as filaments. Si and O, which come from different nucleosynthetic layers of the star, are observed to be coincident in some regions, and separated by >500 km s -1 in others. Observed ejecta traveling toward us are, on average, ˜800 km s -1 slower than the material traveling away from us. We compare our observations to recent supernova explosion models and find that no single model can simultaneously reproduce all the observed features. However, models of different supernova explosions can collectively produce the observed geometries and structures of the emission interior to Cas A's reverse shock. We use the results from the models to address the conditions during the supernova explosion, concentrating on asymmetries in the shock structure. We also predict that the back surface of Cassiopeia A will begin brightening in ∼30 years, and the front surface in ˜100 years. We then used similar observations from 3 regions on Cas A's reverse shock in order to create more 3-dimensional maps. In these regions, we observe supernova ejecta both immediately before and during the shock-ejecta interaction. We determine that the

  6. Mechanical-mathematical modeling for landslide process

    NASA Astrophysics Data System (ADS)

    Svalova, V.

    2009-04-01

    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

  7. Xanthe Terra Landslide in IR

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    This is a daytime IR image of a chaos region within Xanthe Terra. As with earlier images, the landslide in this image is caused by the failure of steep slopes releasing material to form the landslide deposit.

    Image information: IR instrument. Latitude 3.1, Longitude 309.7 East (50.3 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  8. Accuracy assessment of landslide prediction models

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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.

  9. Hazard assessment of the Tidal Inlet landslide and potential subsequent tsunami, Glacier Bay National Park, Alaska

    USGS Publications Warehouse

    Wieczorek, G.F.; Geist, E.L.; Motyka, R.J.; Jakob, M.

    2007-01-01

    An unstable rock slump, estimated at 5 to 10????????10 6 m3, lies perched above the northern shore of Tidal Inlet in Glacier Bay National Park, Alaska. This landslide mass has the potential to rapidly move into Tidal Inlet and generate large, long-period-impulse tsunami waves. Field and photographic examination revealed that the landslide moved between 1892 and 1919 after the retreat of the Little Ice Age glaciers from Tidal Inlet in 1890. Global positioning system measurements over a 2-year period show that the perched mass is presently moving at 3-4 cm annually indicating the landslide remains unstable. Numerical simulations of landslide-generated waves suggest that in the western arm of Glacier Bay, wave amplitudes would be greatest near the mouth of Tidal Inlet and slightly decrease with water depth according to Green's law. As a function of time, wave amplitude would be greatest within approximately 40 min of the landslide entering water, with significant wave activity continuing for potentially several hours. ?? 2007 Springer-Verlag.

  10. Source and progression of a submarine landslide and tsunami: The 1964 Great Alaska earthquake at Valdez

    NASA Astrophysics Data System (ADS)

    Parsons, Tom; Geist, Eric L.; Ryan, Holly F.; Lee, Homa J.; Haeussler, Peter J.; Lynett, Patrick; Hart, Patrick E.; Sliter, Ray; Roland, Emily

    2014-11-01

    Like many subduction zone earthquakes, the deadliest aspects of the 1964 M = 9.2 Alaska earthquake were the tsunamis it caused. The worst of these were generated by local submarine landslides induced by the earthquake. These caused high runups, engulfing several coastal towns in Prince William Sound. In this paper, we study one of these cases in detail, the Port Valdez submarine landslide and tsunami. We combine eyewitness reports, preserved film, and careful posttsunami surveys with new geophysical data to inform numerical models for landslide tsunami generation. We review the series of events as recorded at Valdez old town and then determine the corresponding subsurface events that led to the tsunami. We build digital elevation models of part of the pretsunami and posttsunami fjord-head delta. Comparing them reveals a ~1500 m long region that receded 150 m to the east, which we interpret as the primary delta landslide source. Multibeam imagery and high-resolution seismic reflection data identify a ~400 m wide chute with hummocky deposits at its terminus, which may define the primary slide path. Using these elements we run hydrodynamic models of the landslide-driven tsunamis that match observations of current direction, maximum inundation, and wave height at Valdez old town. We speculate that failure conditions at the delta front may have been influenced by manmade changes in drainage patterns as well as the fast retreat of Valdez and other glaciers during the past century.

  11. The low-cost GNSS GEOMON system for monitoring landslide displacements

    NASA Astrophysics Data System (ADS)

    Demierre, Michel; Malet, Jean-Philippe; Folladore, Laurent; Boetzlé, Pierre; Martin, Jeanneret; Ferhat, Gilbert; Ulrich, Patrice

    2016-04-01

    Analysis of landslide hazard requires continuous and high frequency ground-based surface displacement monitoring at numerous locations. The low-cost GEOMON GNSS system, developped by Infrasurvey in collaboration with the research institutes HEIG-VD / Geomatics and HEIG-VD / MISC-DC, is currently tested experimentally in France by EOST (Ecole et Observatoire des Sciences de la Terre) for the French Landslide Observatory OMIV. The objective of this work is to present the technical solution of the GEOMON GNSS and the results of a field campaign performed during the summer 2015 at the Super-Sauze landslide (France) and at the Hohberg landslide (Switzerland). The GNSS GEOMON system is based on low-cost L1 receiver, the transmission of the phase observations by radio to a base station located outside of the landslide or stored internally on SD cards, and a rapid processing with the open source RTKLib processing software. The performance of the GNSS GEOMON system in real field monitoring conditions will be presented.

  12. The relationship between the slope angle and the landslide size derived from limit equilibrium simulations

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Li; Liu, Chun-Guo; Chang, Zu-Feng; Zhou, Qing

    2016-01-01

    Katz et al. (2014) carried out a study of controls on the size and geometry of landslides using two-dimensional discrete element numerical simulations. One of their conclusions is that in addition to the peak strength of the slope material, the initial slope angle is another factor that controls the amount of material available for landslides, thus the size, of the resultant landslide. It means that in steeper slopes, more material disintegrates for a given material strength, and consequently the produced landslide is larger. However, in our studies based on limit equilibrium simulations, the sliding mass volume decreases with the increasing slope angle for a given material strength, just contrary to the result of Katz et al. One possible explanation is that when the slope angle in our model increases, the geometry of the potential critical slip surface changes, leading to a decrease of the amount of material available for potential sliding that compensates the increasing gravity effect owing to the enlargement of the slope angle. It suggests that there exist different controls of the slope angle on the landslide size for given material strength.

  13. Landslides, ground subsidence, icefall-debris avalanches triggered by the April 2015 Nepal-Gorkha Earthquake

    NASA Astrophysics Data System (ADS)

    Fukuoka, H.; Bhandary, N. P.

    2015-12-01

    A M7.8 earthquake rattled the vast area surrounding Kathmandu, Nepal's capital city on April 25, 2015. The epicenter is located in Gorkha and the rupture area extended about 100 km long and 150 km wide estimated from the aftershock distribution. Accelerometer record at Kathmandu shows that the main shock predominant period is 5 s and PGA is smaller than 0.2 g, because of Kathmandu basin's thick deposits. The Japanese expert investigation team dispatched thereafter found numerous small- to large-scale landslides in the earthquake fault rupture zone except Kathmandu basin. Those characteristics are (1) uncountable rock falls were observed which claimed largest casualties in the mountain communities; (2) as many landslides were reactivated since most of the territory is landslide-prone hill slopes; (3) large-scale rock slides resulting in landslide dam creation, were confirmed by the immediate satellite imagery analysis; (4) In the Langtang village in Himalaya mountains, a icefall - debris avalanche was triggered, claiming the lives of about 1/3 of the residents; (5) subsidence sites along the highway of artificial fills and adjacent communities of Kathmandu were observed; (6) Small-scale landslides and subsidence were observed in some of UNSCO's World heritage sites.

  14. DEM simulation for landslide process and barrier dam formation on the mountainous highway

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Kai; Lee, Ching-Fang; Wei, Lun-Wei; Chou, Hsien-Ter; Chu, Sheng-Shin

    2013-04-01

    A barrier dam induced by landslide in Hanyuan, Sichuan, China occurred on August 6th, 2009. An approximately 9x106 m3 sliding mass dumped rapidly into the Dadu River and buried the new highway S306. After the major landslide, the large-scale debris mass caused the secondary shallow avalanche at the opposite bank and even formed a barrier dam with a length of 100 m and a height of 40 m crossing the Dadu River. The corresponding backwater effect submerged the upstream village over 10 km. This study adopts DEM simulation to examine the dynamic landslide process and understand the triggering mechanism of barrier dam. Based on the numerical investigation, the results showed that the sliding behavior can be classified into three stages: first initial stage with high potential energy, primary sliding with fast velocity, and final stage of impacting river channel. In addition, the energy balance principle for dynamic landslide is also verified with the DEM simulation. With respect to the consideration of hazard managements, one hopes the result can assist engineers to evaluate dangerous potential region and plan protecting construction on the steep mountainous area. Keywords:Landslide, barrier dam, DEM, dynamic process, backwater.

  15. Automatic landslides detection on Stromboli volcanic Island

    NASA Astrophysics Data System (ADS)

    Silengo, Maria Cristina; Delle Donne, Dario; Ulivieri, Giacomo; Cigolini, Corrado; Ripepe, Maurizio

    2016-04-01

    Landslides occurring in active volcanic islands play a key role in triggering tsunami and other related risks. Therefore, it becomes vital for a correct and prompt risk assessment to monitor landslides activity and to have an automatic system for a robust early-warning. We then developed a system based on a multi-frequency analysis of seismic signals for automatic landslides detection occurring at Stromboli volcano. We used a network of 4 seismic 3 components stations located along the unstable flank of the Sciara del Fuoco. Our method is able to recognize and separate the different sources of seismic signals related to volcanic and tectonic activity (e.g. tremor, explosions, earthquake) from landslides. This is done using a multi-frequency analysis combined with a waveform patter recognition. We applied the method to one year of seismic activity of Stromboli volcano centered during the last 2007 effusive eruption. This eruption was characterized by a pre-eruptive landslide activity reflecting the slow deformation of the volcano edifice. The algorithm is at the moment running off-line but has proved to be robust and efficient in picking automatically landslide. The method provides also real-time statistics on the landslide occurrence, which could be used as a proxy for the volcano deformation during the pre-eruptive phases. This method is very promising since the number of false detections is quite small (<5%) and is reducing when the size of the landslide increases. The final aim will be to apply this method on-line and for a real-time automatic detection as an improving tool for early warnings of tsunami-genic landslide activity. We suggest that a similar approach could be also applied to other unstable non-volcanic also slopes.

  16. The large landslide of Carlantino, in the Daunian sub-Apennine (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Canora, F.; Fidelibus, M. D.; Pellicani, R.; Spilotro, G.

    2009-04-01

    , other 4 slides come out in 1984, 1992, 1997 and 2005. Many other minor slides reached the channel at several lower elevations. A big part of the earth body, detached in 1984, never reached the accumulation zone as it stopped at about half the length of the channel. There are several points of interest in the study of the behaviour of these large slides. The most important are the large extent of the landslide body and the coexistence in the upper, lower and lateral parts of strain and stress fields somewhat independent. As an example, 30 years after the last catastrophic movement of the upper part of the landslide body, the accumulation zone reveals still today the effects of small deformations. In a similar manner, the stress field along various zones around the main upper fault can be different, leading to different stability conditions of the top area. The high permeability of the calcarenites overlying clayey soils determine the conditions of perennial feeding of the landslide body by groundwater. Temperature and conductivity logs carried out in numerous boreholes drilled along the slide body allowed tracing the preferential groundwater pathways and recognizing the groundwater feeding zones. The monitoring of the slide has been and is performed with several techniques, including the most recent ones, with different levels of performance, as single beam laser pointers, TDR (Time Domain Reflectometry), and Acoustic Emission measurement. The last topic under investigation is the response of the slide to the seasonal changes of the reservoir level, in terms of kinematics and in terms of chemical interactions of freshwater with interstitial clay water.

  17. Quantifying the effect of landslide-derived sediments on detrital thermochronology

    NASA Astrophysics Data System (ADS)

    Whipp, David M.; Ehlers, Todd A.

    2014-05-01

    Analysis of modern river sediment using detrital thermochronology can provide a record of tectonic activity, surface denudation and sediment transport by surface processes. Ideal sediment samples contain datable mineral grains that represent bedrock exposed in the entire catchment. However, in steep mountainous catchments in active orogens, where detrital thermochronology is advantageous, bedrock landslides can produce a significant fraction of basin sediment. Individual landslides contribute sediment from a restricted region within the catchment and may invalidate the assumption that the sediment sample represents the entire drainage area. We use a simple numerical model of landslide sediment production in combination with the 3D thermokinematic and thermochronometer age prediction software Pecube to determine the magnitude of the influence of landslides on modern river sediment samples. Model landslides are distributed randomly in the catchment following a defined frequency-magnitude relationship and the rate of landslide sediment production is scaled to a defined rock exhumation rate. A sample of n ages is selected at random from the catchment mouth after 1-1000 years of sediment accumulation to simulate variable sediment residence times within the catchment. Sub-basins are also sampled to determine the influence of landslides as a function of basin area. Bedrock landsliding strongly affects catchment detrital cooling age distributions, particularly for shorter sediment residence times. We focus on the Nyadi drainage basin in the central Nepal Himalaya, where published detrital muscovite 40Ar/39Ar cooling age distributions from samples collected five years apart differ in spite of having a sufficient number of dated mineral grains to record the basin age distribution (n = 34 and n = 111). Using a Monte Carlo method, we compare the observed age distributions to 10,000 predicted age distributions of n randomly selected ages and find ~97% of the predicted age

  18. A multi-disciplinary approach to study coastal complex landslides: the case of Torino di Sangro (Central Italy)

    NASA Astrophysics Data System (ADS)

    Sciarra, Marco; Carabba, Luigi; Urbano, Tullio; Calista, Monia

    2016-04-01

    stress-strain numerical modeling solved by a Finite Difference Method (FLAC 2D). This study suggests that rock falls and shallow landslide are hazardous phenomenal that involve the near-surface cover of a bigger and more complex landslide. The distinction between secondary processes, which appear to be the most hazardous in the short-term, and deep-seated one, demonstrated that accurate multi-approach analysis provide important information that can be supportive for local administration and decision makers, and for the comprehension of the factors controlling large and deep-seated landslide affecting the Adriatic coastal slopes.

  19. GIS-based analysis of 1933 Diexi Landslides and dam breach on the Min River, Sichuan, China

    NASA Astrophysics Data System (ADS)

    Ling, Song; Evans, Stephen G.

    2014-05-01

    Due to complex tectonic and geomorphologic factors, the Tibetan Plateau and its surrounding areas, are particularly prone to landslides. Rivers have deeply cut into bedrock, forming narrow valleys that are especially prone to landslide damming. Numerous landslide damming and subsequent dam breaching events are recorded from the region in historical documents and the geosciece literature; these include events at the Dadu River (1786), Diexi (1933), Tanggudong (1967), Yigong (2000), and Tangjiashan (2008). We report the results of a GIS-based analysis of earthquake-generated landslide dams at Diexi. The Diexi Earthquake (M=7.5) occurred on August 25, 1933 and induced a series of giant landslides along the Min River, some of which blocked the river and formed three large landslide lakes. The landslide dam located furthest downstream breached on October 9, 1933, 45 days after the earthquake. The outburst flood resulted in huge damage to the downstream area killing 2,423 people, one of the most serious landslide-related disasters in China during the 20th Century. In the present work, GIS analysis is applied to the Diexi Landslides, based on a review of historical documents and previous studies, data collected during field work, and remote sensing and SRTM-3 digital terrain data. We attempted to determine the precise locations of the 1933 landslides and measured dam height, cross-section area, and volume of the damming landslides. Due to the lack of topographic data before the 1933 earthquake, data of the landslide lakes, including maximum water elevation and total impounded volume can only be estimated. Using credible water levels and inferred submerged topography we calculate an outburst volume for the 1933 event. Moreover, cross-sections are made for both the damming area and the Min River downstream in order to make a general assessment of the damage due to the subsequent flood. Maximum flood discharge is estimated by regression equations. The two remaining lakes on

  20. The influence of different type of landslide for the preparation of statistical multivariate landslide susceptibility models

    NASA Astrophysics Data System (ADS)

    Ghosh, S.; Reichenbach, P.; Rossi, M.; Guzzetti, F.; van Westen, C.; Carranza, E. J. M.

    2009-04-01

    The results of multivariate landslide statistical susceptibility models are highly sensitive to the type of statistical and spatial distribution of the mass movement used as grouping variable, and to the type of geofactors used as explanatory variables. Different classification of landslide data set could result in different model performance and validation fit. Exploiting a discriminant analysis (DA) and a logistic regression (LR) models, we prepared different landslide susceptibility zonation for a study area around Kurseong town in the Darjeeling Himalaya region, Eastern India. To prepare the models, we used as training data set, 342 shallow translational rock slides and 168 shallow translational debris slides, which occurred between 1968 and 2003. To validate the models we used a different set of landslide that occurred between 2004 and 2007. 62 relevant factors including morphometric and geo-environmental parameters were used as explanatory variables. We present and discuss the performance and the validation results of the landslide susceptibility zonation prepared with the two different statistical multivariate models using as grouping variables - the rock slides data set, the debris slides data set and the two type of landslides data set together. The discriminate analysis performs better than the logistic regression and this is probably due to the: a) lack of coherence in the selected training data set and the corresponding explanatory variables; b) landslide type classification problems; c) frequency distribution of landslide/no-landslide mapping units.

  1. Method and apparatus for imaging through 3-dimensional tracking of protons

    NASA Technical Reports Server (NTRS)

    Ryan, James M. (Inventor); Macri, John R. (Inventor); McConnell, Mark L. (Inventor)

    2001-01-01

    A method and apparatus for creating density images of an object through the 3-dimensional tracking of protons that have passed through the object are provided. More specifically, the 3-dimensional tracking of the protons is accomplished by gathering and analyzing images of the ionization tracks of the protons in a closely packed stack of scintillating fibers.

  2. Landslide incidence in the North of Portugal: Analysis of a historical landslide database based on press releases and technical reports

    NASA Astrophysics Data System (ADS)

    Pereira, Susana; Zêzere, José Luís; Quaresma, Ivânia Daniela; Bateira, Carlos

    2014-06-01

    This work presents and explores the Northern Portugal Landslide Database (NPLD) for the period 1900-2010. NPLD was compiled from press releases (regional and local newspapers) and technical reports (reports by civil protection authorities and academic works); it includes 628 landslides, corresponding to 5.7 landslides per year on average. Although 50% of landslides occurred in the last 35 years of the series, the temporal distribution of landslides does not show any regular increase with time. The relationship between annual precipitation and landslide occurrence shows that reported landslides tend to be more frequent in wetter years. Moreover, landslides occur mostly in the wettest months of the year (December, January and February), which reflects the importance of rainfall in triggering slope instability. Most landslides cause damage that affects people and/or structures; 69.4% of the landslides in Northern Portugal caused 136 fatalities, 173 injured and left 460 persons homeless. More than half of the total landslides (321 landslides) led to railway or motorway closures and 49 landslides destroyed 126 buildings. The NPLD is compared with a landslide database for the whole of Portugal constructed from a single daily national newspaper covering the same reference period. It will be demonstrated that the regional and local newspapers are more effective than the national newspaper in reporting damaging landslides in the North of Portugal. Like other documentary-based landslide inventories, the NPLD does not accurately report non-damaging landslides. Therefore, NPLD was found unsuitable to validate municipal-scale landslide susceptibility models derived from detailed geomorphology-based landslide inventories.

  3. ALISSA: Abridged Landslide Inventory of Spain for synoptic Susceptibility Assessment

    NASA Astrophysics Data System (ADS)

    Hervás, Javier

    2014-05-01

    ALISSA is a concise although fairly spatially distributed, small-scale landslide inventory covering peninsular Spain and the Balearic Islands. The inventory was primarily aimed to provide point locations of undifferentiated landslides to calibrate and validate the susceptibility model used to produce the first version of the 1 km cell size (approximately 1:1 million scale), generic European Landslide Susceptibility Map (ELSUS 1000 v1) in 2013. The map is the result of collaborative work between BGR (Hanover, Germany), JRC (Ispra, Italy), CNRS-IPGS (Strasbourg, France) and CNR-IRPI (Perugia, Italy), with help from many mapping organisations throughout Europe which provided landslide locations, in support to the EU Thematic Strategy for Soil Protection regarding the identification of landslide priority areas in Europe. This limited landslide inventory was needed to complete pan-European landslide susceptibility assessment since no nationwide inventory fairly representing landslide occurrence in Spain was published. ALISSA is compiled from published documents, including mainly scientific literature, technical reports, and geological, geotechnical and geomorphological maps, complemented with media news for very recent landslides not yet published in the literature and unpublished work by the author in some areas. The spatial dataset (inventory map) consists of point features corresponding to landslide centroids, which have been crosschecked, validated and geo-referenced on Google Earth to a location accuracy generally within 100 m, which for the smaller landslides is mainly dependent on Google Earth spatial accuracy. In areas where Google Earth imagery does not provide suitable spatial resolution landslide location validation is performed using web-based 2-D satellite/aerial imagery viewers available in the country such as Iberpix or SigPac, or even through interpretation of Panoramio photos on Google Earth. Landslide type, when documented, and locations are thus

  4. What Shape is a Landslide? Statistical Patterns in Landslide Length to Width Ratio

    NASA Astrophysics Data System (ADS)

    Taylor, Faith E.; Malamud, Bruce D.; Witt, Annette

    2015-04-01

    We present a variety of methods to approximate landslide shapes by ellipses, to test the goodness of fit of an elliptical approximation to each landslide shape and to examine the probability distribution of the length-to-width ratio (L/W) of the corresponding ellipses in two substantially complete landslide inventories. The planimetric shape of an individual landslide area is controlled by factors such as terrain morphology, material involved and speed, with landslide shapes varying in total area (AL), type of shape, and their length-to-width ratios. Here, we use mapped polygons from two substantially complete inventories: (i) 11,111 landslides triggered by the 1994 (M = 6.7) Northridge Earthquake, USA (ii) 9,594 landslides triggered by heavy rain during the 1998 Hurricane Mitch in Guatemala. For each landslide polygon, various methods of approximating an elliptical shape were tested. The best method found was fitting a convex hull (CH) to each landslide polygon, approximating an ellipse with equivalent area (ACH) and Perimeter (PCH) of the convex hull and then scaling this ellipse to match the area of the original landslide (AL). The goodness-of-fit (e) of elliptical approximations was tested using a measure of the area of intersection (AI) between the original landslide polygon area (AL) and the elliptical approximation: e = 1 - (2(AL - AI)/AL) =-1+2 AI/AL. The goodness-of-fit e ranges from -1 for an imperfect fit and +1 for a perfect fit. We found that the percentage of landslides having a 'good fit' (e ≥ 0.5) of the ellipse to the inventory landslide polygons were 99% of landslides from the Northridge inventory and 84% of landslides from the Guatemala inventory. For these landslides, the non-dimensional value of the ratio of the ellipse length-to-width (L/W) was calculated. For the Guatemala landslides, 50 % of landslide ellipse L/W values are ≤ 2.17, and 90 % of values are ≤ 3.6. For the Northridge landslides, 50 % of landslide ellipse L/W values are

  5. Landslide Education as part of the LAMPRE Research Project

    NASA Astrophysics Data System (ADS)

    Malamud, Bruce D.; Mihir, Monika; Taylor, Faith

    2015-04-01

    This paper discusses some of the on-line landslide educational resources available via LAMPRE (www.lampre-project.eu), a Euro 2.0M ten-partner EC FP7 funded research project ending 2/2015 devoted to landslide modelling and tools for vulnerability assessment preparedness and recovery management. LAMPRE Educational is a collection of talks, activities and other resources aimed at non-experts (general public, student, teachers and decision makers) to help them better understand the general background, processes, issues and resources available for landslides and triggered landslide events. In this paper we will discuss some of the specific LAMPRE Educational activities and resources available on the LAMPRE web site including: (i) LAMPRE landslide webcast talks and workshops explaining the basics of landslides and triggered events, (ii) A LAMPRE Google Earth Practical for the identification of landslides (15 pages), (iii) A LAMPRE Interactive Presentation on landslides and triggered landslide events (available as a PREZI presentation), (iv) A set of 25 LAMPRE Landslide Frequently Asked Questions (FAQs), (v) A set of web links to general landslide information (8 links), landslide videos and photos (14 links), landslide activities and teaching (9 links). The web site for LAMPRE Educational has been the most widely of all LAMPRE web pages (e.g., the landslide FAQs averaging 300 hits per month over 16 months), one sign, in addition to physical based education activities we have done, of the success of LAMPRE Educational.

  6. Great landslide events in Italian artificial reservoirs

    NASA Astrophysics Data System (ADS)

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

    2005-09-01

    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.

  7. Spatial three-dimensional landslide susceptibility mapping tool and its applications

    NASA Astrophysics Data System (ADS)

    Xie, Mowen; Tetsuro, Esaki; Qiu, Cheng; Jia, Lin

    applied for mapping the landslide susceptibility of three examples: the first one for city planning, the second for predicting the possible landslide influence around a past slope disaster, and the third for mapping landslide along a national route. Based on numerous Monte Carlo simulation, the possible critical landslide bodies have been identified, which cannot be carried out by using the traditional slope stability analyses.

  8. A Novel Method of Orbital Floor Reconstruction Using Virtual Planning, 3-Dimensional Printing, and Autologous Bone.

    PubMed

    Vehmeijer, Maarten; van Eijnatten, Maureen; Liberton, Niels; Wolff, Jan

    2016-08-01

    Fractures of the orbital floor are often a result of traffic accidents or interpersonal violence. To date, numerous materials and methods have been used to reconstruct the orbital floor. However, simple and cost-effective 3-dimensional (3D) printing technologies for the treatment of orbital floor fractures are still sought. This study describes a simple, precise, cost-effective method of treating orbital fractures using 3D printing technologies in combination with autologous bone. Enophthalmos and diplopia developed in a 64-year-old female patient with an orbital floor fracture. A virtual 3D model of the fracture site was generated from computed tomography images of the patient. The fracture was virtually closed using spline interpolation. Furthermore, a virtual individualized mold of the defect site was created, which was manufactured using an inkjet printer. The tangible mold was subsequently used during surgery to sculpture an individualized autologous orbital floor implant. Virtual reconstruction of the orbital floor and the resulting mold enhanced the overall accuracy and efficiency of the surgical procedure. The sculptured autologous orbital floor implant showed an excellent fit in vivo. The combination of virtual planning and 3D printing offers an accurate and cost-effective treatment method for orbital floor fractures. PMID:27137437

  9. An illustrated landslide handbook for developing nations

    USGS Publications Warehouse

    Highland, Lynn M.; Bobrowsky, Peter

    2008-01-01

    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

  10. Landslide susceptibility map: from research to application

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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

  11. Statistical Signature of Deep-seated Landslides

    NASA Astrophysics Data System (ADS)

    Gangodagamage, C.; Foufoula-Georgiou, E.; Belmont, P.; Mackey, B. H.; Fuller, T. K.

    2014-12-01

    We investigate the statistical signature of deep-seated landslides using basin wide topographic data and flowpath arrangement and explore the extent to which these globally derived signatures can be used to locally map landslides. We used directed distance from the divide, which accounts for the distance traveled along flowpaths starting from significant ridgelines, as a scale parameter and demonstrate that local slope vs. directed distance and curvature vs. local slope offer powerful means for identifying the presence of landslides in a landscape. By exploring a threshold on the probability distribution of local slopes conditional on directed distance we show that mapping of landslide features is possible. We apply the methodology to three 0.5 to 2.5 km2 watersheds in northern California and document three regions of distinct geomorphic signatures [Gangodagamage et al., 2011, http://dx.doi.org/10.1029/2010WR009252]. In region A, hillslope gradient increases with distance from the divide and flowpaths are divergent or parallel. Region B corresponds to the zone with highly convergent flowpaths and exhibits the strongest signal of landslide related features. Region C is a moderately convergent zone that transitions into the fluvial channel network. Next, we use specific quantiles of the probability density function of local slopes conditioned on directed distance from the divide to map individual landslide features. This analysis allows us to explore the 3D morphometry of the landslide affected basins and to develop a supervised set of ensemble templates for landslides as a function of local slope vs. directed distance (DD) relationship. Then we use this template and demonstrate that the landslide affected basins can be identified by iterative matching the landslide signature template with the basin wide signatures of the tributary basins in the South Fork Eel River, CA. Finally, we perform a multiscale analysis of the contributing area parameterized by directed

  12. Cellular Automata Models Applied to the Study of Landslide Dynamics

    NASA Astrophysics Data System (ADS)

    Liucci, Luisa; Melelli, Laura; Suteanu, Cristian

    2015-04-01

    Landslides are caused by complex processes controlled by the interaction of numerous factors. Increasing efforts are being made to understand the spatial and temporal evolution of this phenomenon, and the use of remote sensing data is making significant contributions in improving forecast. This paper studies landslides seen as complex dynamic systems, in order to investigate their potential Self Organized Critical (SOC) behavior, and in particular, scale-invariant aspects of processes governing the spatial development of landslides and their temporal evolution, as well as the mechanisms involved in driving the system and keeping it in a critical state. For this purpose, we build Cellular Automata Models, which have been shown to be capable of reproducing the complexity of real world features using a small number of variables and simple rules, thus allowing for the reduction of the number of input parameters commonly used in the study of processes governing landslide evolution, such as those linked to the geomechanical properties of soils. This type of models has already been successfully applied in studying the dynamics of other natural hazards, such as earthquakes and forest fires. The basic structure of the model is composed of three modules: (i) An initialization module, which defines the topographic surface at time zero as a grid of square cells, each described by an altitude value; the surface is acquired from real Digital Elevation Models (DEMs). (ii) A transition function, which defines the rules used by the model to update the state of the system at each iteration. The rules use a stability criterion based on the slope angle and introduce a variable describing the weakening of the material over time, caused for example by rainfall. The weakening brings some sites of the system out of equilibrium thus causing the triggering of landslides, which propagate within the system through local interactions between neighboring cells. By using different rates of

  13. Unification of color postprocessing techniques for 3-dimensional computational mechanics

    NASA Technical Reports Server (NTRS)

    Bailey, Bruce Charles

    1985-01-01

    To facilitate the understanding of complex three-dimensional numerical models, advanced interactive color postprocessing techniques are introduced. These techniques are sufficiently flexible so that postprocessing difficulties arising from model size, geometric complexity, response variation, and analysis type can be adequately overcome. Finite element, finite difference, and boundary element models may be evaluated with the prototype postprocessor. Elements may be removed from parent models to be studied as independent subobjects. Discontinuous responses may be contoured including responses which become singular, and nonlinear color scales may be input by the user for the enhancement of the contouring operation. Hit testing can be performed to extract precise geometric, response, mesh, or material information from the database. In addition, stress intensity factors may be contoured along the crack front of a fracture model. Stepwise analyses can be studied, and the user can recontour responses repeatedly, as if he were paging through the response sets. As a system, these tools allow effective interpretation of complex analysis results.

  14. Assessing the Economic Cost of Landslide Damage in Low-Relief Regions: Case Study Evidence from the Flemish Ardennes (Belgium)

    NASA Astrophysics Data System (ADS)

    Vranken, L.; Van Turnhout, P.; Van Den Eeckhaut, M.; Vandekerckhove, L.; Vantilt, G.; Poesen, J.

    2012-04-01

    Several regions around the globe are at risk to incur damage from landslides. These landslides cause significant structural and functional damage to public and private buildings and infrastructure. Numerous studies investigated how natural factors and human activities control the (re-)activation of landslides. However, few studies have concentrated on a quantitative estimate of the overall damage caused by landslides at a regional scale. This study therefore starts with a quantitative economic assessment of the direct and indirect damage caused by landslides in the Flemish Ardennes (Belgium), a low-relief region (area=ca. 700 km2) susceptible to landslides. Based on focus interviews as well as on semi-structured interviews with homeowners, civil servants (e.g. from the technical services from the various towns), or with the owners and providers of lifelines such as electricity and sewage, we have quantitatively estimated the direct and indirect damage induced by landsliding and this for a 10 to 30 year period (depending on the type of infrastructure or buildings). Economic damage to public infrastructure and buildings was estimated for the entire region, while for private damage 10 cases with severe to small damage were quantified. For example, in the last 10 year, costs of road repair augmented to 814 560 €. Costs to repair damaged roads that have not yet been repaired, were estimated at 669 318 €. In the past 30 years, costs of measures to prevent road damage augmented to at least 14 872 380 €. More than 90% of this budget for preventive measures was spent 30 years ago, when an important freeway was damaged and had to be repaired. These preventive measures (building a grout wall and improving the drainage system) were effective as no further damage has been reported until present. To repair and prevent damage to waterworks and sewage systems, expenditures amounted to 551 044 € and this for the last 30 years. In the past 10 years, a new railway line

  15. Statistical Seismic Landslide Analysis: an Update

    NASA Astrophysics Data System (ADS)

    Lee, Chyi-Tyi

    2015-04-01

    Landslides are secondary or induced features, whose recurrence is controlled by the repetition of triggering events, such as earthquakes or heavy rainfall. This makes seismic landslide hazard analysis more complicated than ordinary seismic hazard analysis, and it requires multi-stage analysis. First, susceptibility analysis is utilized to divide a region into successive classes. Then, it is necessary to construct a relationship between the probability of landslide failure and earthquake intensity for each susceptibility class for a region, or to find the probability of failure surface using the susceptibility value and earthquake intensity as independent variables at the study region. Then, hazard analysis for the exceedance probability of earthquake intensity is performed. Finally, an analysis of the spatial probability of landslide failure under a certain return-period earthquake is drawn. This study uses data for Chi-Chi earthquake induced landslides as the training data set to perform the susceptibility analysis and probability of failure surface analysis. A regular probabilistic seismic hazard analysis is also conducted to map different return-period Arias intensities. Finally a seismic landslide hazard map for the whole of Taiwan is provided.

  16. Mathematical modelling of submarine landslide motion

    NASA Astrophysics Data System (ADS)

    Burminskij, A.

    2012-04-01

    Mathematical modelling of submarine landslide motion The paper presents a mathematical model to calculate dynamic parameters of a submarine landslide. The problem of estimation possible submarine landslides dynamic parameters and run-out distances as well as their effect on submarine structures becomes more and more actual because they can have significant impacts on infrastructure such as the rupture of submarine cables and pipelines, damage to offshore drilling platforms, cause a tsunami. In this paper a landslide is considered as a viscoplastic flow and is described by continuum mechanics equations, averaged over the flow depth. The model takes into account friction at the bottom and at the landslide-water boundary, as well as the involvement of bottom material in motion. A software was created and series of test calculations were performed. Calculations permitted to estimate the contribution of various model coefficients and initial conditions. Motion down inclined bottom was studied both for constant and variable slope angle. Examples of typical distributions of the flow velocity, thickness and density along the landslide body at different stages of motion are given.

  17. A multi-annual landslide inventory for the assessment of shallow landslide susceptibility - Two test cases in Vorarlberg, Austria

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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.

  18. Landslide process and types of groundwater- and rainfall-induced landslide in a flume experiment

    NASA Astrophysics Data System (ADS)

    Wu, Chunhung

    2016-04-01

    Most of the landslide cases in Taiwan were induced by rainfall or earthquake events. The landslide cases which were only induced by groundwater were very rare. The groundwater-induced deep landslide with landslide depth of 15-20 m and landslide volume of around 220000 m3 occurred at 3.1K of Highway No. 3 on Apr. 25, 2010 in Taiwan. The groundwater-induced landslide is a fast-moving dip-slope landslide. The purpose of this study is to understand the landslide processes and types of groundwater- and rainfall-induced landslide in the flume landslide experiments. The landslide experiments were carried out in the flume with the length, width, and height of 1.5 m, 0.3 m, and 0.3 m, respectively. The research proceeded 18 flume landslide experiments and observed the processes and types under different setting conditions, including soil deposited height (5 cm and 10 cm), channel slope (4.4°, 8.7°, and 13.0°), groundwater discharge (51.3 and 31.7 cm3/sec), rainfall intensity (0.093 and 0.037 mm/sec), soil diameter (0.5 and 0.9 mm). The research also measured the water content and pore pressure by using ECH2O Dielectric Aquameter sensors and TML KPC-200KPB sensors, and recorded the experiment processes by two Video cameras from side and top views. Some conclusions can be made based on the results of the flume landslide experiments. The porosity of soil decides the development speed of wet wave in the soil. The pile soil deposition with a high porosity of soil or a large soil diameter is hard to from landslide because the development speed of wet wave in the soil is fast but the water content in the soil is low than the threshold of water content to induce the landslide. The height of pile soil deposition decides the wetness and landslide types of pile soil deposition. The height of pile soil deposition gets higher, the pile soil deposition is harder to be totally wet, the seriousness of landslide gets lighter and the total sediment yield gets less. The slope of channel

  19. Prediction of shallow landslide occurrence: Validation of a physically-based approach through a real case study.

    PubMed

    Schilirò, Luca; Montrasio, Lorella; Scarascia Mugnozza, Gabriele

    2016-11-01

    In recent years, physically-based numerical models have frequently been used in the framework of early-warning systems devoted to rainfall-induced landslide hazard monitoring and mitigation. For this reason, in this work we describe the potential of SLIP (Shallow Landslides Instability Prediction), a simplified physically-based model for the analysis of shallow landslide occurrence. In order to test the reliability of this model, a back analysis of recent landslide events occurred in the study area (located SW of Messina, northeastern Sicily, Italy) on October 1st, 2009 was performed. The simulation results have been compared with those obtained for the same event by using TRIGRS, another well-established model for shallow landslide prediction. Afterwards, a simulation over a 2-year span period has been performed for the same area, with the aim of evaluating the performance of SLIP as early warning tool. The results confirm the good predictive capability of the model, both in terms of spatial and temporal prediction of the instability phenomena. For this reason, we recommend an operating procedure for the real-time definition of shallow landslide triggering scenarios at the catchment scale, which is based on the use of SLIP calibrated through a specific multi-methodological approach. PMID:27341114

  20. Activation of Deep-Seated Landslides in NW California After Wildfires in 2006 and 2008

    NASA Astrophysics Data System (ADS)

    Mikulovsky, R. P.; de la Fuente, J. A.; Bell, A.; Stevens, M.; Levitan, F.

    2012-12-01

    Widespread wildfires in the Klamath Mountains and Coast Ranges of northwestern California burned tens of thousands of acres within the Klamath, Shasta-Trinity, Six Rivers, and Mendocino National Forests in 2006 and 2008. Much of the area burned was underlain by older dormant, deep seated landslide deposits. Numerous landslides were activated within the older complexes during the winters of 2009-2010, and 2010-2011, years with average precipitation. Post-fire debris flows associated with shallow landslides and mobilization of shallow hill slope material and channel bed deposits are well-documented in the literature. These responses typically occur in the first few years after the fire. They have been attributed to fire-induced reduction in soil permeability, loss of ground cover and organic material, and loss of fine root support. In contrast, activation of deep-seated landslides after wildfire has been observed but not as thoroughly documented. Such activations can occur immediately after the fire, in response to ordinary precipitation events. However, delayed responses of 10 years or more are known. Fire-related loss of root support is not likely a factor in the activation of these landslides because their failure planes are typically located well below the rooting depth. The 10 plus year reaction time strongly suggests that movement is related to changes in slope hydrology, since landslide deposits are known to have complex groundwater flow paths (Iverson and Major 1987, Iverson 2000). Activation of such landslides can have far-reaching watershed effects, involving large debris slides from the margins and toes of the older landslides. These debris slides may generate debris flows. In rare cases, landslide dams can form. For these reasons, it is essential to identify dormant landslides within burned areas, and their burn severity, in order to better understand how they react in response to varying wildfire severities. Four landslides which occurred after 2008 are

  1. Assessment of Active Landslides in Sanbaro Sago Valley, Blue-Nile Catchment, Ethiopia

    NASA Astrophysics Data System (ADS)

    Hailemariam Gugsa, Trufat

    2010-05-01

    In fall of 2009, a detail field mapping was carried out in the Sanbaro Sago Valley, south-eastern of Blue-Nile catchment, to inspect the landslide processes that affected the livelihood of more than 6,000 peoples. The valley is a part of Ethiopian highlands where long histories of rainfall triggered landslides are prominent. The villagers suffered the recurring landslides for the last five years, even at present; there are numerous evidences of active landslides, with some actual slides currently taking place. The nature their activity indicate high probability of destructive phenomena within the foreseeable future. The landslides already damaged houses, farm plots and drainage ditch, as well; more than 40 causalities are recorded. Most of the dwellers have been permanently displaced from their residences, as they lost their houses and farm plots. A preliminary zoning was made through the interpretation of satellite images (+ETM Land sat) that drape over the digital elevation model of the area, which followed by detail field investigation to map the geological, geomorphological, and anthropogenic factors that contribute to the landslide activity. The valley consists of low lying graben bounded by steep scarps that characterized by highly weathered Tertiary basaltic rocks covered with Quaternary deposits. Structurally controlled, alluvial and denudational landforms are present. There are distinct geomorphic units formed by differences in the lithology of the various basalt types. The Quaternary deposits along the ridge that has many rills and incised gullies are characterized by weathered basalts and alluvial-colluvial deposits. The elevation of the valley ranges from 1290m to 3200m m.a.s.l. The steep slopes, volcanic hills, exposed on the downthrown side of the major scarps have been modified by erosion, resulting in a highly dissected topography with steep gullies. This makes the steep slopes of the ridge to be one of landslide prone areas. Many of the active

  2. An updated catalogue of landslides and floods with human consequences in Italy

    NASA Astrophysics Data System (ADS)

    Salvati, P.; Bianchi, C.; Guzzetti, F.

    2009-04-01

    We have updated the catalogue of landslides and floods with direct consequences to the population in Italy. The catalogue covers the 1941-year period between 68 and 2008, and lists landslides and floods that have resulted in deaths, missing persons, injuries and homeless. The catalogue was complied searching a variety of bibliographical and archive sources, including the national catalogue of landslide and flood events in Italy (http://sici.irpi.cnr.it), and five regional catalogues of historical landslide and flood events. We have mapped, at 1:25,000 or 1:100,000 scales, the exact or the approximate location of all the sites were harmful landslides and floods have occurred in the considered period. Analysis of the catalogues indicates that at least 57,450 people have died, went missing or were injured in 3020 landslide and flood events. This corresponds to a long term average of about 30 casualties per year, and 1.5 harmful event per year. In the new catalogue, the number of landslide events with casualties (1770) is largest than the number of flood events with casualties (1233). However, the number of fatalities caused by foods (38,750, 75%) is largest than the number of landslide fatalities (13,542, 25%). Further analysis of the catalogue reveals that the total number of homeless exceeded 873,400, corresponding to a long term, yearly average of 450 people. Harmful landslide and flood events were inventoried in 2496 of the 8102 Italian municipalities (31%). Fatal events (i.e., events resulting in deaths and missing persons) occurred in 1378 municipalities (17%), and were most numerous in northern Italy. The region where the landslide death toll was highest is the Campania region, in southern Italy, where 3319 people died or went missing. The figure corresponds to 25% of total number of reported landslide fatalities. The large number of fatalities in this region is due mostly to soil slips and debris flows in areas where a thin cover of volcanic ash overlies

  3. Climate services for adapting landslide hazard prevention measures in the Vrancea Seismic Region

    NASA Astrophysics Data System (ADS)

    Micu, Dana; Balteanu, Dan; Jurchescu, Marta; Sima, Mihaela; Micu, Mihai

    2014-05-01

    The Vrancea Seismic Region is covering an area of about 8 000 km2 in the Romanian Curvature Carpathians and Subcarpathians and it is considered one of Europe's most intensely multi-hazard-affected areas. Due to its geomorphic traits (heterogeneous morphostructural units of flysch mountains and molasse hills and depressions), the area is strongly impacted by extreme hydro-meteorological events which are potentially enhancing the numerous damages inflicted to a dense network of human settlements. An a priori knowledge of future climate change is a useful climate service for local authorities to develop regional adapting strategies and adequate prevention/preparedness frameworks. This paper aims at integrating the results of the high-resolution climate projections over the 21st century (within the FP7 ECLISE project) into the regional landslide hazard assessment. The requirements of users (Civil Protection, Land management, local authorities) for this area refer to reliable and high-resolution spatial data on landslide and flood hazard for short and medium-term risk management strategies. An insight into the future behavior of climate variability in the Vrancea Seismic Region, based on future climate projections of three regional models, under three RCPs (2.6, 4.5, 8.6), suggests a clear warming, both annually and seasonally and a rather limited annual precipitation decrease, but with a strong change of seasonality. A landslide inventory of 2485 cases (shallow and medium seated earth, debris and rock slides and earth and debris flows) was obtained based on large scale geomorphological mapping and aerial photos support (GeoEye, DigitalGlobe; provided by GoogleEarth and BingMaps). The landslides are uniformly distributed across the area, being considered representative for the entire morphostructural environment. Landslide susceptibility map was obtained using multivariate statistical analysis (logistic regression), while a relative landslide hazard index was computed

  4. A new methodology for deterministic landslide risk assessment at the local scale

    NASA Astrophysics Data System (ADS)

    Cotecchia, F.; Santaloia, F.; Lollino, P.; Vitone, C.; Mitaritonna, G.; Parise, M.

    2009-04-01

    -hydro-mechanical classes, the external factors and the landslide typologies are recognised and formulated. These connections may be recognized as result of phenomenological studies, limit equilibrium analyses of the slopes, in-situ monitoring and numerical modelling of the landslide processes. The application of the procedure to the hazard assessment within a given portion of the region represents the second phase of the methodology. The research work is developed with reference to a test-site area, the Daunia region, located at the eastern margin of the southern Apennines, which is a portion of the chain belt along the subduction zone between the African and the Euro-Asiatic plates, where slopes are made up of tectonised and fissured soils and rocks. Here, frequent and intense landsliding involve the slopes extensively and repeatedly, restraining urban development. The research is currently investigating the applicability of the deterministic methodology to the landslide hazard assessment of the urban territories in the region.

  5. Connectivity of earthquake-triggered landslides with the fluvial network: Implications for landslide sediment transport after the 2008 Wenchuan earthquake

    NASA Astrophysics Data System (ADS)

    Li, Gen; West, A. Joshua; Densmore, Alexander L.; Hammond, Douglas E.; Jin, Zhangdong; Zhang, Fei; Wang, Jin; Hilton, Robert G.

    2016-04-01

    Evaluating the influence of earthquakes on erosion, landscape evolution, and sediment-related hazards requires understanding fluvial transport of material liberated in earthquake-triggered landslides. The location of landslides relative to river channels is expected to play an important role in postearthquake sediment dynamics. In this study, we assess the position of landslides triggered by the Mw 7.9 Wenchuan earthquake, aiming to understand the relationship between landslides and the fluvial network of the steep Longmen Shan mountain range. Combining a landslide inventory map and geomorphic analysis, we quantify landslide-channel connectivity in terms of the number of landslides, landslide area, and landslide volume estimated from scaling relationships. We observe a strong spatial variability in landslide-channel connectivity, with volumetric connectivity (ξ) ranging from ~20% to ~90% for different catchments. This variability is linked to topographic effects that set local channel densities, seismic effects (including seismogenic faulting) that regulate landslide size, and substrate effects that may influence both channelization and landslide size. Altogether, we estimate that the volume of landslides connected to channels comprises 43 + 9/-7% of the total coseismic landslide volume. Following the Wenchuan earthquake, fine-grained (<~0.25 mm) suspended sediment yield across the Longmen Shan catchments is positively correlated to catchment-wide landslide density, but this correlation is statistically indistinguishable whether or not connectivity is considered. The weaker-than-expected influence of connectivity on suspended sediment yield may be related to mobilization of fine-grained landslide material that resides in hillslope domains, i.e., not directly connected to river channels. In contrast, transport of the coarser fraction (which makes up >90% of the total landslide volume) may be more significantly affected by landslide locations.

  6. The role of hillslope topography on shallow landslides activation and basin saturation propensity

    NASA Astrophysics Data System (ADS)

    Lanni, C.; Pretto, I.; Rigon, R.

    2009-12-01

    Shallow Landslides are one of the most important causes of loss of human life and socio-economic damage related to the hydro-geological risk issues. In the past years a big number of researches have developed tools to assess for the stability condition of hillslopes at the basin-scale. Montgomery and Dietrich (1994), for instance, with their own SHALSTAB model, give a simple way to evaluate the safety factor of mountain hillslopes, coupling the infinite slope stability model with a very simple steady-state hydrological model based on the work by O'Loughlin (1986) and which has similarities to TOPOG (Beven and Kirkby, 1979). The state of art gives the possibility to evaluate the transient nature of the generated pore-pressure fields within soil-thickness during and after the rainfalls. A valuable tool to fulfill this purpose may be the GEOtop model (Rigon et al., 2006) born to solve the 3-dimensional form of Richards’ equation. The present work, which was held using GEOtop model, investigates the stability conditions and the water table level of nine characteristic hillslope types when steady-state conditions are reached. The artificial simple basins are created combining three different curvature's profile (straight, concave and convex) and three different plan shapes (parallel, convergent and divergent) (fig.1). In the analysis the hillslope soil thickness is imposed constant, while the bedrock is considered impermeable. Different intensity rainfalls are simulated. The results show that in the case of the lowest intensity rainfall, basins with convex shape present higher percentage of saturated area than concave and straight ones. Also, convergent hillslopes generally produce a higher percentage of saturated area than the other plan shapes. Moreover, in the case of higher intensity rainfalls, the concave profile curvature seems to be the first order controller on the saturation process. Regarding the stability conditions, convergent hillslopes generally presents

  7. Characteristics of earthquake-induced landslides and differences compared to storm-induced landslides

    NASA Astrophysics Data System (ADS)

    Lee, C.-T.

    2012-04-01

    Landslides triggered by the Chi-Chi earthquake, as re-mapped from high resolution SPOT images just before the quake and after the quake, are studied and compared to landslides triggered by some typhoon storm events in Taiwan. Several landslide controlling factors are statistically analyzed and compared. This includes slope gradient, slope height (SH), total slope height (TSH), relative slope height (RSH), and others. RSH is defined as SH divided by TSH, and is a measure to indicate a location is close to the toe of a slope (RSH=0) or near the ridge top (RSH=1). A high resolution of DEM was used in the terrain analysis to produce slope gradient, RSH and other derived data. The DEM is of 5mx5m grid in origin and was made by aerial photogrammetry. It is checked and smoothed a little and reduced to 10mx10m grid for following analyses. The results show that slope gradient always is a very important factor controlling the occurrence of landslides, but there is difference in distribution of occurrence frequency between the two. Storm-induced shallow landslides most occurred at slope gradient from 20 degrees to 44 degrees and shows a mode about 33 degrees. Earthquake-induced landslides most occurred at slope gradient from 20 degrees to 54 degrees and shows a mode about 42 degrees for shallow landslide and rock falls. There are fewer occurrences of rock falls in a storm event than that in an earthquake event for a specific region. The results also show that RSH is a very significant factor controlling the location of landslides. Storm-induced shallow landslides most occurred at lower RSH and closer to the river, whereas earthquake-induced landslides occurred at higher RSH and closer to the ridge. In summary, the earthquake-induced landslides are mostly located at a steeper and longer slope and at a higher position of the slope as compared to the storm-induced shallow landslides, and this implies that topographic amplification play a very important role in the earthquake

  8. Assessing Landslide Risk Areas Using Statistical Models and Land Cover

    NASA Astrophysics Data System (ADS)

    Kim, H. G.; Lee, D. K.; Park, C.; Ahn, Y.; Sung, S.; Park, J. H.

    2015-12-01

    Recently, damages due to landslides have increased in Republic of Korea. Extreme weathers like typhoon, heavy rainfall related to climate change are the main factor of the damages. Especially, Inje-gun, Gangwon-do had severe landslide damages in 2006 and 2007. In Inje-gun, 91% areas are forest, therefore, many land covers related to human activities were adjacent to forest land. Thus, establishment of adaptation plans to landslides was urgently needed. Landslide risk assessment can serve as a good information to policy makers. The objective of this study was assessing landslide risk areas to support establishment of adaptation plans to reduce landslide damages. Statistical distribution models (SDMs) were used to evaluate probability of landslide occurrence. Various SDMs were used to make landslide probability maps considering uncertainty of SDMs. The types of land cover were classified into 5 grades considering vulnerable level to landslide. The landslide probability maps were overlaid with land cover map to calculate landslide risk. As a result of overlay analysis, landslide risk areas were derived. Especially agricultural areas and transportation areas showed high risk and large areas in the risk map. In conclusion, policy makers in Inje-gun must consider the landslide risk map to establish adaptation plans effectively.

  9. Evaluation on the Efficiency of Subsurface Drainage in Chiu-Fen Landslide at Northern Taiwan

    NASA Astrophysics Data System (ADS)

    Ying, L. Y.; Lin, D. G.

    2015-12-01

    For administrative district, the Chiu-Fen landslide is situated at northern Taiwan and comes within the jurisdiction of Ruei-Fang district, New Taipei City Government. Chiu-Fen village is a famous spot for sightseeing and tourism in Southeast Asia. In the last decade, for economic purpose, a vast area of slope land in Chiu-Fen area was reclaimed into business and commercial districts. However, due to the complicated geological and hydrological conditions, improper reclamation, and lack of appropriate soil and water conservation facilities, large scale landslides are frequently triggered by typhoon rainfall and causes damages to the transportation and residential building in the community. As a consequence, the government initiated a comprehensive field investigations and remediation plans to stabilize the landslide from 1997 and the remediation works were concentrated on subsurface drainages, namely the application of drainage well (a vertical shaft with multi-level horizontal drainage boreholes). To investigate the efficiency of drainage wells on the landslide, the A1-profile in the landslide which covers the drainage wells W2 and W4 was selected for a series of rainfall seepage and slope stability analyses. In addition, a 48-hrs design rainfall with return period of 25, 50 and 100 years based on the local meteorological data bank was adopted for the analyses. The numerical results indicate the factor safety FS of the three potential sliding surfaces within A1-profile are constantly keeping greater than one (FS > 1.0) and without decreasing with the elapsed time during rainfall. This implies that the subsurface drainage works can drain off the infiltrated rainwater from a high intensity and long duration rainfall and preserve the slope stability of landslides from deterioration. Finally, the efficiency of the drainage wells can be evaluated quantitatively in terms of the time-dependent factor of safety and the pore water pressure distribution on several potential

  10. Slope stability susceptibility evaluation parameter (SSEP) rating scheme - An approach for landslide hazard zonation

    NASA Astrophysics Data System (ADS)

    Raghuvanshi, Tarun Kumar; Ibrahim, Jemal; Ayalew, Dereje

    2014-11-01

    In this paper a new slope susceptibility evaluation parameter (SSEP) rating scheme is presented which is developed as an expert evaluation approach for landslide hazard zonation. The SSEP rating scheme is developed by considering intrinsic and external triggering parameters that are responsible for slope instability. The intrinsic parameters which are considered are; slope geometry, slope material (rock or soil type), structural discontinuities, landuse and landcover and groundwater. Besides, external triggering parameters such as, seismicity, rainfall and manmade activities are also considered. For SSEP empirical technique numerical ratings are assigned to each of the intrinsic and triggering parameters on the basis of logical judgments acquired from experience of studies of intrinsic and external triggering factors and their relative impact in inducing instability to the slope. Further, the distribution of maximum SSEP ratings is based on their relative order of importance in contributing instability to the slope. Finally, summation of all ratings for intrinsic and triggering parameter based on actual observation will provide the expected degree of landslide in a given land unit. This information may be utilized to develop a landslide hazard zonation map. The SSEP technique was applied in the area around Wurgessa Kebelle of North Wollo Zonal Administration, Amhara National Regional State in northern Ethiopia, some 490 km from Addis Ababa. The results obtained indicates that 8.33% of the area fall under Moderately hazard and 83.33% fall within High hazard whereas 8.34% of the area fall under Very high hazard. Further, in order to validate the LHZ map prepared during the study, active landslide activities and potential instability areas, delineated through inventory mapping was overlain on it. All active landslide activities and potential instability areas fall within very high and high hazard zone. Thus, the satisfactory agreement confirms the rationality of

  11. The October 16, 2013 rainfall-induced landslides and associated lahars at Izu Oshima Volcano, Japan

    NASA Astrophysics Data System (ADS)

    Miyabuchi, Yasuo; Maeno, Fukashi; Nakada, Setsuya

    2015-09-01

    Intense rainfall related to the typhoon T1326 on October 15-16, 2013 (total 824 mm; maximum hourly rainfall 118.5 mm) triggered numerous landslides and associated lahars at Izu Oshima Volcano, the northernmost part of Izu Mariana volcanic arc, Japan. The landslides were concentrated mainly in a 2-km2 area located on the western slope of Izu Oshima Volcano. Most of the landslides were shallow soil slips (< 2 m thick) in unconsolidated fallout tephra layers overlying lava flows and pyroclastic rocks. The rupture surfaces of them were located near the base of Y1 tephra (AD 1777-1778) and/or the base of Y4 tephra (AD 1421). The Y1 and Y4 tephras differ from the underlying paleosols in permeability, grain size and degree of compaction. The saturated hydraulic conductivities of the paleosols were one to two orders of magnitude smaller than those of the overlying Y1 and Y4 tephras. Most landslides mobilized completely into lahars, traveling along stream channels or flat slopes and flooding at the foot of the volcano. The associated lahars severely damaged inhabited areas and caused thirty five fatalities. Although the lahars eroded slopes and transported boulders up to 1 m in diameter and a large amount of woody debris, they contained more than 90% of sand-to-silt-size particles, similar in composition to the original sliding materials. Sediment discharge volumes from three basins were estimated at 1.8-4.1 × 104 m3/km2, based on debris volumes trapped by sediment retention dams. The characteristics of rainfall-induced landslides and associated lahars at Izu Oshima Volcano in 2013 provide an important lesson about future non-eruption-related landslide and lahar hazards at tephra-rich volcanoes.

  12. Coseismic and Post-seismic landsliding: insights from seismological modeling and landslide map time series.

    NASA Astrophysics Data System (ADS)

    Marc, Odin; Hovius, Niels; Meunier, Patrick; Uchida, Taro; Gorum, Tolga

    2016-04-01

    Earthquakes impart a catastrophic forcing on hillslopes, that often lead to widespread landsliding and can contribute significantly to sedimentary and organic matter fluxes. We present a new expression for the total area and volume of populations of earthquake-induced landslides.This model builds on a set of scaling relationships between key parameters, such as landslide density, ground acceleration, fault size, earthquake source depth and seismic moment, derived from geomorphological and seismological observations. To assess the model we have assembled and normalized a catalogue of landslide inventories for 40 earthquakes. We have found that low landscape steepness systematically leads to over-prediction of the total area and volume of landslides.When this effect is accounted for, the model is able to predict within a factor of 2 the landslide areas and associated volumes for about two thirds of the cases in our databases. This is a significant improvement on a previously published empirical expression based only on earthquake moment. This model is suitable for integration into landscape evolution models, and application to the assessment of secondary hazards and risks associated with earthquakes. However, it only models landslides associated to the strong ground shaking and neglects the intrinsic permanent damage that also occurred on hillslopes and persist for longer period. With time series of landslide maps we have constrained the magnitude of the change in landslide susceptibility in the epicentral areas of 4 intermediate to large earthquakes. We propose likely causes for this transient ground strength perturbations and compare our observations to other observations of transient perturbations in epicentral areas, such as suspended sediment transport increases, seismic velocity reductions and hydrological perturbations. We conclude with some preliminary observations on the coseismic mass wasting and post-seismic landslide enhancement caused by the 2015 Mw.7

  13. Regional coseismic landslide hazard assessment without historical landslide inventories: A new approach

    NASA Astrophysics Data System (ADS)

    Kritikos, Theodosios; Robinson, Tom R.; Davies, Tim R. H.

    2015-04-01

    Currently, regional coseismic landslide hazard analyses require comprehensive historical landslide inventories as well as detailed geotechnical data. Consequently, such analyses have not been possible where these data are not available. A new approach is proposed herein to assess coseismic landslide hazard at regional scale for specific earthquake scenarios in areas without historical landslide inventories. The proposed model employs fuzzy logic and geographic information systems to establish relationships between causative factors and coseismic slope failures in regions with well-documented and substantially complete coseismic landslide inventories. These relationships are then utilized to estimate the relative probability of landslide occurrence in regions with neither historical landslide inventories nor detailed geotechnical data. Statistical analyses of inventories from the 1994 Northridge and 2008 Wenchuan earthquakes reveal that shaking intensity, topography, and distance from active faults and streams are the main controls on the spatial distribution of coseismic landslides. Average fuzzy memberships for each factor are developed and aggregated to model the relative coseismic landslide hazard for both earthquakes. The predictive capabilities of the models are assessed and show good-to-excellent model performance for both events. These memberships are then applied to the 1999 Chi-Chi earthquake, using only a digital elevation model, active fault map, and isoseismal data, replicating prediction of a future event in a region lacking historic inventories and/or geotechnical data. This similarly results in excellent model performance, demonstrating the model's predictive potential and confirming it can be meaningfully applied in regions where previous methods could not. For such regions, this method may enable a greater ability to analyze coseismic landslide hazard from specific earthquake scenarios, allowing for mitigation measures and emergency response plans

  14. Monsoon Rainfall and Landslides in Nepal

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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

  15. Costs and deaths of landslides in Europe

    NASA Astrophysics Data System (ADS)

    Haque, Ubydul; Blum, Philipp

    2016-04-01

    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.

  16. Implementation of a geodatabase of published and non-published data on the catastrophic Vaiont landslide

    NASA Astrophysics Data System (ADS)

    Ghirotti, M.; Genevois, R.; Superchi, L.; Floris, M.; Stead, D.

    2009-04-01

    On the 9th October 1963 a catastrophic landslide suddenly occurred on the southern slope of the Vaiont dam reservoir. A mass of approximately 270 million m3 collapsed into the reservoir generating a wave which overtopped the dam and hit the town of Longarone and other villages: almost 2000 people lost their lives. Numerous questions, legal, economic, societal, and scientific have accompanied its history, before and after October 9th 1963. Several investigations and attempted interpretations of the slope collapse have been carried out during the last 45 years, however a comprehensive explanation of both the triggering and the dynamics of the phenomenon has yet to be provided. Research on the Vaiont landslide, published in the international literature after 1963, can conveniently subdivided into the following: 1) papers based on geological and geomorphological data collected at the Vaiont site; 2) papers focussing on specific aspects including the geotechnical properties of the materials involved, the physical and rheological behavior of the failure mass and the varied methods of stability analysis applied in order to understand the factors involved in landslide initiation and development; 3) papers dealing with the Vaiont landslide in a more comprehensive way. The Vaiont landslide has significantly increased our understanding of the kinematics and dynamics of such catastrophic phenomena. However, much of the data on the Vaiont slide exists in a non-electronic hard copy format. A geodatabase on the Vaiont Slide has been developed, utilising and updating the information collected by Genevois & Ghirotti (2005). An electronic bibliography of all published papers, theses and non-published technical reports, and all available site data forms the core of a newly developed geodatabase on the Vaiont landslide. In addition, data on engineering geological mapping, topography, rock mechanics, groundwater and monitoring have been centralized in a GIS system to allow a re

  17. Experiences of a WEB based test site platform for landslide susceptibility and the use of remote sensing interferometric techniques for monitoring landslide movements in Sweden

    NASA Astrophysics Data System (ADS)

    Löfroth, H.; Hultén, C.; Ledwith, M.; Nisser-Larsson, M.; Righini, G.

    2009-04-01

    Slope stability is a problem of great concern in Sweden. Each year, numerous minor slides occur and every ten to twenty years a major slide develops, often in built-up areas. The landslides are quite deep seated and rapid. Slopes with prerequisites for landslides consists normally either of clay slopes (inclination > 1:10) or rather steep slopes in areas with silt and sand. In Sweden there are guidelines for stability analyses of natural slopes issued by the Swedish Commission on Slope Stability in 1995. The guidelines are structured in such a way that an investigation is carried out in four stages with increasing extent (Sällfors, Larsson and Ottosson, 1996). The different stages, subsequently referred to as the Swedish methodology, are as follows: Stage 1: Overview stability mapping carried out individually for each municipality. Stage 1 is divided in a pilot study and two Sub-stages (Fallsvik and Viberg, 1998). In the Pilot study, sub-areas in the municipalities considered to be mapped are identified. In Sub-stage 1a, the land is divided into areas with and without prerequisites for initial slope failure in clay and silt, while in Sub-stage 1b an overview assessment of the stability under prevailing conditions based on survey calculations is done. The overview stability mapping in Sub-stage 1b forms the basis for decisions on where detailed stability investigations should be performed in Stage 2. The principal aim of Stage 2 is to identify whether there is a real stability problem or not. Based on geotechnical field and laboratory investigations the prerequisites for the calculations are clarified. Slope stability calculations are then carried out with both undrained and combined analysis normally for circular slip surfaces using reliable computer programs. If needed, following the detailed investigation an extended and eventually also a supplementary investigation are carried out. Within the framework of PREVIEW (EU FP6 Project), Landslides Platform, a Web

  18. Predictive Analysis of Landslide Activity Using Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Markuzon, N.; Regan, J.; Slesnick, C.

    2012-12-01

    Landslides are historically one of the most damaging geohazard phenomena in terms of death tolls and socio-economic losses. Therefore, understanding the underlying causes of landslides and how environmental phenomena affect their frequency and severity is of critical importance. Of specific importance for mitigating future damage is increasing our understanding of how climate change will affect landslide severity, occurrence rates, and damage. We are developing data driven models aimed at predicting landslide activity. The models learn multi-dimensional weather and geophysical patterns associated with historical landslides and estimate location-dependent probabilities for landslides under current or future weather and geophysical conditions. Our approach uses machine learning algorithms capable of determining non-linear associations between dependent variables and landslide occurrence without requiring detailed knowledge of geomorphology. Our primary goal in year one of the project is to evaluate the predictive capabilities of data mining models in application to landslide activity, and to analyze if the approach will discover previously unknown variables and/or relationships important to landslide occurrence, frequency or severity. The models include remote sensing and ground-based data, including weather, landcover, slope, elevation and drainage information as well as urbanization data. The historical landslide dataset we used to build our preliminary models was compiled from City of Seattle landslide files, United States Geological Survey reports, newspaper articles, and a verified subset of the Seattle Landslide Database that consists of all reported landslides within Seattle, WA, between 1948 and 1999. Most of the landslides analyzed to-date are shallow. Using statistical analysis and unsupervised clustering methods we have thus far identified subsets of weather conditions that lead to a significantly higher landslide probability, and have developed

  19. Geomorphological mapping of shallow landslides using UAVs

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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

  20. Geoelectric monitoring of the Bagnaschino landslide (Italy)

    NASA Astrophysics Data System (ADS)

    Jochum, Birgit; Supper, Robert; Ottowitz, David; Pfeiler, Stefan; Kim, Jung-Ho; Lovisolo, Mario

    2013-04-01

    Landslides are one of the major natural threats to human lives, settlements and infrastructure. Permanent geoelectrical monitoring using the GEOMON4D instrumentation in combination with high resolution displacement monitoring by means of the DMS system was performed at an active landslide area in Italy (Bagnaschino). These sites are part of a geoelectrical monitoring network of the Geological Survey of Austria, which currently comprises six permanently monitored landslides in Europe. The Bagnaschino site represents a landslide/earthflow reactivated within an old landslide mass. The old landslide is situated on the slopes of the Val Casotto about 4 km SE of Torre Mondovì (NW Italy). Evident indications of deep-seated gravitational deformation suggest that the current slopes are in a condition of limit-equilibrium and are predisposed to slow instability, triggered most probably by rain and/or snow melting and river erosion at the foot. The recent landslide was activated during 1994 rainfall event. It covers an estimated area of 150,000 m² and comprises a displaced material of 1.2 million m³. It endangers a regional road and potential formation of a dam. For the purpose of early warning a DMS monitoring column with 60 m length was installed in October 2008. Total displacement recorded by DMS during the events between 2008 and 2010 was 600 mm. Subsequently, the GEOMON4D geoelectric monitoring system was installed there in 2010. Resistivity measurements are performed along a 224 m long profile, which is oriented parallel to the main movement direction. Its midpoint is next to the DMS station. One set of data comprising around 4000 gradient-type measurements is taken every 4 hours. For power supply a combination of a fuel cell and a solar panel is used. Within the observation interval one distinct displacement event was monitored. This event was accompanied by a decrease of electric resistivity. In addition to our standard analysis of resistivity data (e.g. time

  1. Landslide disaster avoidance: learning from Leyte

    NASA Astrophysics Data System (ADS)

    Davies, T. R.

    2006-12-01

    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

  2. Uncertainty associated with regional landslide risk analysis - a case study in Buzau County, Romania

    NASA Astrophysics Data System (ADS)

    Zumpano, Veronica; Ciurean, Roxana; Micu, Mihai; Balteanu, Dan; Glade, Thomas

    2013-04-01

    When analyzing the risk for a region where landslides constitute a threat for the society and the environment, a fully quantitative approach often becomes impracticable. The magnitude, frequency and location of landslides and a reasonably complete inventory of historical events is commonly not available. Likewise, a thorough investigation of the damaged assets and quantification of losses is rarely possible. Nevertheless, an alternative approach can be engaged in areas where information regarding the environmental conditions leading to the occurrence of landslides including their relative location, and the characteristics and distribution of elements at risk are known. This contribution proposes a methodology for a landslide risk analysis applicable at regional scale taking into account the spatial probability and consequences of past damaging events. Since the temporal information used to calculate the detailed hazard probability is missing, a susceptibility analysis is performed by using a data-driven Bayesian method (Weights of Evidence modeling technique) which analyzes the relation between a training set (past landslide events) and multiple predisposing factors (lithology, landuse, slope, aspect, internal relief, altitude), in order to predict areas that are less-to-more susceptible to landslide initiation. The consequence analysis is based on a generalized assessment of vulnerability, exposure and value of the elements at risk (i.e. buildings and roads) using cadastral and statistical data. For both components of the risk analysis (susceptibility analysis and consequence analysis) an estimation of uncertainty is performed by defining a central value (which represents the statistical mean) and a measure of value range (minimum and maximum) of the input parameters. As the procedure operates at a spatial level, the distribution of risk and the annual probability of expected losses are expressed numerically as well as spatially with the use of GIS. The developed

  3. Flood and Landslide Applications of Near Real-time Satellite Rainfall Products

    NASA Technical Reports Server (NTRS)

    Hong, Yang; Adler, Robert F.; Negri, Andrew; Huffman, George J.

    2007-01-01

    Floods and associated landslides are one of the most widespread natural hazards on Earth, responsible for tens of thousands of deaths and billions of dollars in property damage every year. During 1993-2002, over 1000 of the more than 2,900 natural disasters reported were due to floods. These floods and associated landslides claimed over 90,000 lives, affected over 1.4 billion people and cost about $210 billion. The impact of these disasters is often felt most acutely in less developed regions. In many countries around the world, satellite-based precipitation estimation may be the best source of rainfall data due to lack of surface observing networks. Satellite observations can be of essential value in improving our understanding of the occurrence of hazardous events and possibly in lessening their impact on local economies and in reducing injuries, if they can be used to create reliable warning systems in cost-effective ways. This article addressed these opportunities and challenges by describing a combination of satellite-based real-time precipitation estimation with land surface characteristics as input, with empirical and numerical models to map potential of landslides and floods. In this article, a framework to detect floods and landslides related to heavy rain events in near-real-time is proposed. Key components of the framework are: a fine resolution precipitation acquisition system; a comprehensive land surface database; a hydrological modeling component; and landslide and debris flow model components. A key precipitation input dataset for the integrated applications is the NASA TRMM-based multi-satellite precipitation estimates. This dataset provides near real-time precipitation at a spatial-temporal resolution of 3 hours and 0.25deg x 0.25deg. By careful integration of remote sensing and in-situ observations, and assimilation of these observations into hydrological and landslide/debris flow models with surface topographic information, prediction of useful

  4. Open and disconnected magnetic field lines within coronal mass ejections in the solar wind: Evidence for 3-dimensional reconnection

    NASA Technical Reports Server (NTRS)

    Gosling, J. T.; Birn, J.; McComas, D. J.; Phillips, J. L.; Hesse, M.

    1995-01-01

    Measurements of suprathermal electron fluxes in the solar wind at energies greater than approximatley 80 eV indicate that magnetic field lines within coronal mass ejections. CMEs, near and beyond 1 AU are normally connected to the Sun at both ends. However, a preliminary reexamination of events previously identified as CMEs in the ISEE 3 data reveals that about 1/4 of all such events contain limited regions where field lines appear to be either connected to the Sun at only one end or connected to the outer heliosphere at both ends. Similar intervals of open and disconnected field lines within CMEs have been identified in the Ulysses observations. We believe that these anomalous field topologies within CMEs are most naturally interpreted in terms of 3-dimensional reconnection behind CMEs close to the Sun. Such reconnection also provides a natural explanation both for the flux rope topology of many CMEs as well as the coronal loops formed during long-duration solar soft X ray events. Although detailed numerical simulations of 3-dimensional reconnection behind CMEs are not yet available, such simulations have been done for the qualitatively similar geometry that prevails within the geomagnetic tail. Those simulations of plasmoid formation in the geomagnetic tail do produce the mixture of field topologies within plasmoids discussed here for CMEs.

  5. Relations between hydrology and velocity of a continuously moving landslide-evidence of pore-pressure feedback regulating landslide motion?

    USGS Publications Warehouse

    Schulz, W.H.; McKenna, J.P.; Kibler, J.D.; Biavati, G.

    2009-01-01

    We measured displacement, pore-water pressure, and climatic conditions for 3 years at the continuously moving Slumgullion landslide in Colorado, USA. The landslide accelerated when pore-water pressure increased within the landslide body, but this occurred as pore-water pressure decreased along the landslide margin. The decrease probably occurred in response to shear-induced soil dilation at rates greater than pore-pressure diffusion and likely increased resistance to shear displacement and resulted in landslide deceleration. This dilative strengthening has been experimentally observed and explained theoretically, but not previously identified during field studies. Although landslide displacement should have exceeded that required to achieve critical-state density of shear boundaries, observed relocation of these boundaries indicates that shearing is episodic at fixed locations, so it permits renewed dilative strengthening when "fresh" soil is sheared. Thus, dilatant strengthening may be a considerable mechanism controlling landslide velocity, even for landslides that have continuously moved great distances. ?? Springer-Verlag 2009.

  6. Morphology of Submarine Landslides in Puget Sound

    NASA Astrophysics Data System (ADS)

    Smith, S. B.; Karlin, R.

    2003-12-01

    Submarine landslides, probably triggered by large earthquakes, disturb Holocene sediments in Puget Sound. High-resolution seismic reflection profiling and sidescan swath surveys were conducted over large submarine landslides and debris flows. These large slides are in close proximity to the South Whidbey Island fault zone at Possession Point, Mukilteo, and Edgewater; near the Seattle fault off Alki Point; and near the Tacoma fault at Maury Island. The boundaries of the slides were mapped using sidescan swath surveys. Preliminary slide morphologies were determined from the seismic cross-sections. Three large slide complexes with multiple block slides and debris flows are found off Possession Point; the largest of which is 1.5 km x 1.0 km with a maximum thickness of approximately 50 meters. Large sand flows with maximum thicknesses of 30 to 40 meters occur off Mukilteo and Edgewater. An approximately 3.3 km x 2.2 km, 30 meter thick flow off Alki Point was deposited on top of folded sediments within the deformation zone of the Seattle Fault zone. Three large block slides are present off Maury Island; the largest of which is 2.75 km x 1.0 km, with a maximum thickness of approximately 100 meters. The volumes of these landslides are more than an order of magnitude larger than subaerial landslides in the region. Tsunamis generated by landsliding potentially constitute a major seismic hazard in coastal areas of the Puget Lowland.

  7. Landslide and Land Subsidence Hazards to Pipelines

    USGS Publications Warehouse

    Baum, Rex L.; Galloway, Devin L.; Harp, Edwin L.

    2008-01-01

    Landslides and land subsidence pose serious hazards to pipelines throughout the world. Many existing pipeline corridors and more and more new pipelines cross terrain that is affected by either landslides, land subsidence, or both. Consequently the pipeline industry recognizes a need for increased awareness of methods for identifying and evaluating landslide and subsidence hazard for pipeline corridors. This report was prepared in cooperation with the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration, and Pipeline Research Council International through a cooperative research and development agreement (CRADA) with DGH Consulting, Inc., to address the need for up-to-date information about current methods to identify and assess these hazards. Chapters in this report (1) describe methods for evaluating landslide hazard on a regional basis, (2) describe the various types of land subsidence hazard in the United States and available methods for identifying and quantifying subsidence, and (3) summarize current methods for investigating individual landslides. In addition to the descriptions, this report provides information about the relative costs, limitations and reliability of various methods.

  8. Coprates Chasma Landslides in IR

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Today's daytime IR image is of a portion of Coprates Chasma, part of Valles Marineris. As with yesterday's image, this image shows multiple large landslides.

    Image information: IR instrument. Latitude -8.2, Longitude 300.2 East (59.8 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. The 22 March 2014 Oso landslide, Washington, USA

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    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.

  10. Integration of landslide susceptibility products in the environmental plans

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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.

  11. Distribution probability of large-scale landslides in central Nepal

    NASA Astrophysics Data System (ADS)

    Timilsina, Manita; Bhandary, Netra P.; Dahal, Ranjan Kumar; Yatabe, Ryuichi

    2014-12-01

    Large-scale landslides in the Himalaya are defined as huge, deep-seated landslide masses that occurred in the geological past. They are widely distributed in the Nepal Himalaya. The steep topography and high local relief provide high potential for such failures, whereas the dynamic geology and adverse climatic conditions play a key role in the occurrence and reactivation of such landslides. The major geoscientific problems related with such large-scale landslides are 1) difficulties in their identification and delineation, 2) sources of small-scale failures, and 3) reactivation. Only a few scientific publications have been published concerning large-scale landslides in Nepal. In this context, the identification and quantification of large-scale landslides and their potential distribution are crucial. Therefore, this study explores the distribution of large-scale landslides in the Lesser Himalaya. It provides simple guidelines to identify large-scale landslides based on their typical characteristics and using a 3D schematic diagram. Based on the spatial distribution of landslides, geomorphological/geological parameters and logistic regression, an equation of large-scale landslide distribution is also derived. The equation is validated by applying it to another area. For the new area, the area under the receiver operating curve of the landslide distribution probability in the new area is 0.699, and a distribution probability value could explain > 65% of existing landslides. Therefore, the regression equation can be applied to areas of the Lesser Himalaya of central Nepal with similar geological and geomorphological conditions.

  12. Operational early warning of shallow landslides in Norway: Evaluation of landslide forecasts and associated challenges

    NASA Astrophysics Data System (ADS)

    Dahl, Mads-Peter; Colleuille, Hervé; Boje, Søren; Sund, Monica; Krøgli, Ingeborg; Devoli, Graziella

    2015-04-01

    The Norwegian Water Resources and Energy Directorate (NVE) runs a national early warning system (EWS) for shallow landslides in Norway. Slope failures included in the EWS are debris slides, debris flows, debris avalanches and slush flows. The EWS has been operational on national scale since 2013 and consists of (a) quantitative landslide thresholds and daily hydro-meteorological prognosis; (b) daily qualitative expert evaluation of prognosis / additional data in decision to determine warning levels; (c) publication of warning levels through various custom build internet platforms. The effectiveness of an EWS depends on both the quality of forecasts being issued, and the communication of forecasts to the public. In this analysis a preliminary evaluation of landslide forecasts from the Norwegian EWS within the period 2012-2014 is presented. Criteria for categorizing forecasts as correct, missed events or false alarms are discussed and concrete examples of forecasts falling into the latter two categories are presented. The evaluation show a rate of correct forecasts exceeding 90%. However correct forecast categorization is sometimes difficult, particularly due to poorly documented landslide events. Several challenges has to be met in the process of further lowering rates of missed events of false alarms in the EWS. Among others these include better implementation of susceptibility maps in landslide forecasting, more detailed regionalization of hydro-meteorological landslide thresholds, improved prognosis on precipitation, snowmelt and soil water content as well as the build-up of more experience among the people performing landslide forecasting.

  13. Calculations of turbidite deposits and tsunamis from submarine landslides

    SciTech Connect

    Gisler, Galen R; Weaver, Robert P; Gittings, Michael L

    2009-01-01

    Great underwater landslides like Storegga off the Norwegian coast leave massive deposits on the seafloor and must produce enormous tsunamis. Such events have occurred on continental slopes worldwide, and continue to do so. Triggers for such slides include earthquakes, gas hydrate releases, and underwater volcanos. We have petformed a numerical study of such landslides using the multi-material compressible hydrocode Sage in order to understand the relationship between the rheology of the slide material, the configuration of the resulting deposits on the seafloor, and the tsunami that is produced. Instabilities in the fluid-fluid mixing between slide material and seawater produce vortices and swirls with sizes that depend on the rheology of the slide material. These dynamical features of the flow may be preserved as ridges when the sliding material finally stops. Thus studying the configuration of the ridges in prehistoric slides may give us measures of the circumstances under which the slide was initiated. As part of this study, we have also done a convergence test showing that the slide velocity is sensitive to the resolution adopted in the simulation, but that extrapolation to infinite resolution is possible, and can yield good velocities. We will present two-dimensional simulations of schematic underwater slides for our study of rheology, and a three-dimensional simulation in bathymetric conditions that resemble the pre-Storegga Norwegian margin.

  14. A logical framework for ranking landslide inventory maps

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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

  15. An Explicit 3-Dimensional Model for Reactive Transport of Nitrogen in Tile Drained Fields

    NASA Astrophysics Data System (ADS)

    Hill, D. J.; Valocchi, A. J.; Hudson, R. J.

    2001-12-01

    Recently, there has been increased interest in nitrate contamination of groundwater in the Midwest because of its link to surface water eutrophication, especially in the Gulf of Mexico. The vast majority of this nitrate is the product of biologically mediated transformation of fertilizers containing ammonia in the vadose zone of agricultural fields. For this reason, it is imperative that mathematical models, which can serve as useful tools to evaluate both the impact of agricultural fertilizer applications and nutrient-reducing management practices, are able to specifically address transport in the vadose zone. The development of a 3-dimensional explicit numerical model to simulate the movement and transformation of nitrogen species through the subsurface on the scale of an individual farm plot will be presented. At this scale, nitrogen fate and transport is controlled by a complex coupling among hydrologic, agricultural and biogeochemical processes. The nitrogen model is a component of a larger modeling effort that focuses upon conditions typical of those found in agricultural fields in Illinois. These conditions include non-uniform, multi-dimensional, transient flow in both saturated and unsaturated zones, geometrically complex networks of tile drains, coupled surface-subsurface-tile flow, and dynamic levels of dissolved oxygen in the soil profile. The advection-dispersion-reaction equation is solved using an operator-splitting approach, which is a flexible and straightforward strategy. Advection is modeled using a total variation diminishing scheme, dispersion is modeled using an alternating direction explicit method, and reactions are modeled using rate law equations. The model's stability and accuracy will be discussed, and test problems will be presented.

  16. Susceptibility map of triggering landslides due to rainfall forecast as a part of innovative inspire compliant cloud based infrastructure - InGeoCloudS

    NASA Astrophysics Data System (ADS)

    Šinigoj, Jasna; Podboj, Martin; Komac, Marko, ,, dr.; Požar, Mitja; Krivic, Matija; Jemec-Auflič, Mateja, ,, dr.

    2014-05-01

    system is based on near real-time online modelling of landslide hazard level based on the weather (rainfall) forecast and location-based rainfall triggering levels for landslide occurrence. The system uses rainfall data input from the system Aladin (High Resolution Numerical Weather Prediction Project), which is instantly overlaid with the landslide susceptibility map and with the map of the triggering threshold values for each individual cell resulting in a simple five level warning display. The forecast's aim is to warn users of potential hazard in their region and to serve as a preparedness enhancement tool.

  17. Assessing Landslide Characteristics and Developing a Landslide Potential Hazard Map in Rwanda and Uganda Using NASA Earth Observations

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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.

  18. Re-evaluation of Tsunami Hazard in Marmara Sea Generated from the Combined Earthquake and Landslide Sources Focusing on Istanbul, Turkey

    NASA Astrophysics Data System (ADS)

    Latcharote, P.; Suppasri, A.; Imamura, F.; Aytore, B.; Yalciner, A. C.

    2015-12-01

    This study aimed to re-evaluate tsunami hazard in Marmara Sea from earthquake and submarine landslide focusing on the coastal area of Istanbul. For the fault-generated tsunami, the seismic rupture can be propagated along the North Anatolian Fault (NAF) which have evidenced historical tsunami in Marmara Sea. Based on previous research studies, future scenarios are expected to generate tsunami as well as submarine landslide could be triggered by seismic motion which consider fault-generated tsunami and landslide-generated tsunami individually. However, this study want to simulate tsunami propagation generated from the combining earthquake-landslide sources. Therefore, the evaluation of tsunami hazard was discussed in both of the individual case and the combining case of earthquake and submarine landslide through numerical modelling of tsunami wave with mesh size 90 m of bathymetry data. A two-layer numerical model was employed to simulate the landslide-generated tsunami by modeling the interaction between tsunami and submarine landslide with different volume of initial slide. First, tsunami propagation was generated from earthquake sources of Rupture E in the eastern basin and Rupture W in the western basin of Marmara Sea with fault slip 5 m. For Rupture E and Rupture W, maximum tsunami height at shore shoreline could reach 3.4 m and 2.8 m respectively along the coastal area of Istanbul. For combining Rupture E and Rupture W, maximum tsunami height could reach 3.8 m which was a little higher than that of Rupture E. Then, tsunami propagation was generated from landslide sources in the southern neighborhood of Istanbul near Rupture E. For landslide volume of 0.15 m3, 0.6 m3, and 1.5 m3, maximum tsunami height at shore shoreline could reach 3.7 m, 6.9 m and 8.7 m respectively along the coastal area of Istanbul. It was shown that maximum tsunami height from landslide sources was higher than that from earthquake sources depending on the volume of initial slide

  19. A simple and efficient GIS tool for volume calculations of submarine landslides

    NASA Astrophysics Data System (ADS)

    Völker, David Julius

    2010-10-01

    A numeric tool is presented for calculating volumes of topographic voids such as slump scars of landslides, canyons or craters (negative/concave morphology), or alternatively, bumps and hills (positive/convex morphology) by means of digital elevation models embedded within a geographical information system (GIS). In this study, it has been used to calculate landslide volumes. The basic idea is that a (singular) event (landslide, meteorite impact, volcanic eruption) has disturbed an intact surface such that it is still possible to distinguish between the former (undisturbed) landscape and the disturbance (crater, slide scar, debris avalanche). In such cases, it is possible to reconstruct the paleo-surface and to calculate the volume difference between both surfaces, thereby approximating the volume gain or loss caused by the event. I tested the approach using synthetically generated land surfaces that were created on the basis of Shuttle Radar Topography Mission data. Also, I show the application to two real cases, (1) the calculation of the volume of the Masaya Slide, a submarine landslide on the Pacific continental slope of Nicaragua, and (2) the calculation of the void of a segment of the Fish River Canyon, Namibia. The tool is provided as a script file for the free GIS GRASS. It performs with little effort, and offers a range of interpolation parameters. Testing with different sets of interpolation parameters results in a small range of uncertainty. This tool should prove useful in surface studies not exclusively on earth.

  20. Complex submarine landsliding processes caused by subduction of large seamounts along the Middle America Trench

    NASA Astrophysics Data System (ADS)

    Harders, Rieka; Ranero, Cesar R.; Weinrebe, Wilhelm; von Huene, Roland

    2014-05-01

    Subduction of kms-tall and tens-of-km wide seamounts cause important landsliding events at subduction zones around the word. Along the Middle America Trench, previous work based on regional swath bathymetry maps (with 100 m grids) and multichannel seismic images have shown that seamount subduction produces large-scale slumping and sliding. Some of the mass wasting event may have been catastrophic and numerical modeling has indicated that they may have produced important local tsunamis. We have re-evaluated the structure of several active submarine landlide complexes caused by large seamount subduction using side scan sonar data. The comparison of the side scan sonar data to local high-resolution bathymetry grids indicates that the backscatter data has a resolution that is somewhat similar to that produced by a 10 m bathymetry grid. Although this is an arbitrary comparison, the side scan sonar data provides comparatively much higher resolution information than the previously used regional multibeam bathymetry. We have mapped the geometry and relief of the head and side walls of the complexes, the distribution of scars and the different sediment deposits to produce a new interpretation of the modes of landsliding during subduction of large seamounts. The new higher resolution information shows that landsliding processes are considerably more complex than formerly assumed. Landslides are of notably smaller dimensions that the lower resolution data had previously appear to indicate. However, significantly large events may have occur far more often than earlier interpretations had inferred representing a more common threat that previously assumed.

  1. Challenges performing multi-scale, three-dimensional simulations of landslide generated tsunamis on adaptive unstructured meshes

    NASA Astrophysics Data System (ADS)

    Wilson, C. R.; Kramer, S. C.; Collins, G. S.

    2010-12-01

    Linear wave models cannot reproduce the highly nonlinear generation mechanisms required to accurately predict the consequences of landslide-generated tsunamis. Models based on the nonlinear Navier-Stokes equations can simulate complex landslide-water interactions at realistic scales; however, the computing power required for such a simulation can be prohibitively high for large domains with realistic bathymetries. The variable resolution available with the use of unstructured adaptive meshes allows larger domains to be modeled at the same resolution for a lower computational cost than on structured meshes; they are also better at representing complex geometries and bathymetries. However, unstructured meshes introduce extra numerical challenges requiring the use of novel interface preservation techniques coupled with velocity-pressure discretisations that ensure the conservation and boundedness of all materials in the simulation. In this study we describe some of the challenges encountered extending the finite element, finite volume multiple-material fluid dynamics model Fluidity to large-scale landslide-generated tsunami simulations. In particular, we focus on the ability of the model to preserve the balance between the buoyancy and pressure gradient forces. Failure to discretely satisfy this relationship is shown to result in spurious waves that contaminate any physical tsunami signal. However, ensuring that balance is preserved in a computationally efficient manner imposes extra constraints on the dynamic mesh optimisation process. Incorporating these restrictions allows us to validate our model against multi-scale experimental simulations of landslide generated tsunami (see figure). Experimental (top, taken from Di Risio et. al. 2009, doi:10.1029/2008JC004858) and equivalent numerical simulation (bottom) of a subaerial landslide impacting into water. In the experiment the 80cm long landslide produces waves of amplitude 1-2cm around a 9m diameter island in a 50x

  2. Landslide oil field, San Joaquin Valley, California

    SciTech Connect

    Collins, B.P.; March, K.A.; Caballero, J.S.; Stolle, J.M.

    1988-03-01

    The Landslide field, located at the southern margin of the San Joaquin basin, was discovered in 1985 by a partnership headed by Channel Exploration Company, on a farm out from Tenneco Oil Company. Initial production from the Tenneco San Emidio 63X-30 was 2064 BOPD, making landslide one of the largest onshore discoveries in California during the past decade. Current production is 7100 BOPD from a sandstone reservoir at 12,500 ft. Fifteen wells have been drilled in the field, six of which are water injectors. Production from the Landslide field occurs from a series of upper Miocene Stevens turbidite sandstones that lie obliquely across an east-plunging structural nose. These turbidite sandstones were deposited as channel-fill sequences within a narrowly bounded levied channel complex. Both the Landslide field and the larger Yowlumne field, located 3 mi to the northwest, comprise a single channel-fan depositional system that developed in the restricted deep-water portion of the San Joaquin basin. Information from the open-hole logs, three-dimensional surveys, vertical seismic profiles, repeat formation tester data, cores, and pressure buildup tests allowed continuous drilling from the initial discovery to the final waterflood injector, without a single dry hole. In addition, the successful application of three-dimensional seismic data in the Landslide development program has helped correctly image channel-fan anomalies in the southern Maricopa basin, where data quality and severe velocity problems have hampered previous efforts. New exploration targets are currently being evaluated on the acreage surrounding the Landslide discovery and should lead to an interesting new round of drilling activity in the Maricopa basin.

  3. Multidisciplinary study on anthropogenic landslides in Nepal

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  4. Handling Unquantifiable Uncertainties in Landslide Modelling

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Landslides have many negative economic and societal impacts, including the potential for significant loss of life and damage to infrastructure. Slope stability assessment can be used to guide decisions about the management of landslide risk, but its usefulness can be challenged by high levels of uncertainty in predicting landslide occurrence. Prediction uncertainty may be associated with the choice of model that is used to assess slope stability, the quality of the available input data, or a lack of knowledge of how future climatic and socio-economic changes may affect future landslide risk. While some of these uncertainties can be characterised by relatively well-defined probability distributions, for other uncertainties, such as those linked to climate change, there is no agreement on what probability distribution should be used to characterise them. This latter type of uncertainty, often referred to as deep uncertainty, means that robust policies need to be developed that are expected to perform adequately under a wide range of future conditions. In our study the impact of deep uncertainty on slope stability predictions is assessed in a quantitative and structured manner using Global Sensitivity Analysis (GSA) and the Combined Hydrology and Stability Model (CHASM). In particular, we use and combine several GSA methods including the Method of Morris, Regional Sensitivity Analysis and CART, as well as advanced visualization tools. Our example application is a slope in the Caribbean, an area that is naturally susceptible to landslides due to a combination of high rainfall rates, steep slopes, and highly weathered residual soils. Rapid unplanned urbanisation and changing climate may further exacerbate landslide risk in the future. Our example shows how we can gain useful information in the presence of deep uncertainty by combining physically based models with GSA in a scenario discovery framework.

  5. Application of 3-dimensional printing in hand surgery for production of a novel bone reduction clamp.

    PubMed

    Fuller, Sam M; Butz, Daniel R; Vevang, Curt B; Makhlouf, Mansour V

    2014-09-01

    Three-dimensional printing is being rapidly incorporated in the medical field to produce external prosthetics for improved cosmesis and fabricated molds to aid in presurgical planning. Biomedically engineered products from 3-dimensional printers are also utilized as implantable devices for knee arthroplasty, airway orthoses, and other surgical procedures. Although at first expensive and conceptually difficult to construct, 3-dimensional printing is now becoming more affordable and widely accessible. In hand surgery, like many other specialties, new or customized instruments would be desirable; however, the overall production cost restricts their development. We are presenting our step-by-step experience in creating a bone reduction clamp for finger fractures using 3-dimensional printing technology. Using free, downloadable software, a 3-dimensional model of a bone reduction clamp for hand fractures was created based on the senior author's (M.V.M.) specific design, previous experience, and preferences for fracture fixation. Once deemed satisfactory, the computer files were sent to a 3-dimensional printing company for the production of the prototypes. Multiple plastic prototypes were made and adjusted, affording a fast, low-cost working model of the proposed clamp. Once a workable design was obtained, a printing company produced the surgical clamp prototype directly from the 3-dimensional model represented in the computer files. This prototype was used in the operating room, meeting the expectations of the surgeon. Three-dimensional printing is affordable and offers the benefits of reducing production time and nurturing innovations in hand surgery. This article presents a step-by-step description of our design process using online software programs and 3-dimensional printing services. As medical technology advances, it is important that hand surgeons remain aware of available resources, are knowledgeable about how the process works, and are able to take advantage of

  6. Landslide Hazards in the Seattle, Washington, Area

    USGS Publications Warehouse

    Baum, Rex; Harp, Ed; Highland, Lynn

    2007-01-01

    The Seattle, Washington, area is known for its livability and its magnificent natural setting. The city and nearby communities are surrounded by an abundance of rivers and lakes and by the bays of Puget Sound. Two majestic mountain ranges, the Olympics and the Cascades, rim the region. These dramatic natural features are products of dynamic forces-landslides, earthquakes, tsunamis, glaciers, volcanoes, and floods. The same processes that formed this beautiful landscape pose hazards to the ever-growing population of the region. Landslides long have been a major cause of damage and destruction to people and property in the Seattle area.

  7. Landslide Hazards After the 2005 Kashmir Earthquake

    NASA Astrophysics Data System (ADS)

    Bulmer, Mark; Farquhar, Tony; Roshan, Masud; Akhtar, Sadar Saeed; Wahla, Sajjad Karamat

    2007-01-01

    The 8 October 2005 Kashmir earthquake killed 87,300 people and disrupted the lives of several million more. By current estimates, 30,000 still live in camps sited more in accordance with short term expedience than with freedom from risk of natural hazards. In December 2006, the international aid community expressed fears that 50,000 people in Northwest Frontier Province may leave their mountain homes this winter as landslides and avalanches block access roads. As the focus of humanitarian assistance shifts toward restoration of Kashmir's infrastructure, it is important that the persistent hazard of landslides within the earthquake affected region be understood and recognized.

  8. Automatic recognition of landslides based on change detection

    NASA Astrophysics Data System (ADS)

    Li, Song; Hua, Houqiang

    2009-07-01

    After Wenchuan earthquake disaster, landslide disaster becomes a common concern, and remote sensing becomes more and more important in the application of landslide monitoring. Now, the method of interpretation and recognition for landslides using remote sensing is visual interpretation mostly. Automatic recognition of landslide is a new and difficult but significative job. For the purpose of seeking a more effective method to recognize landslide automatically, this project analyzes the current methods for the recognition of landslide disasters, and their applicability to the practice of landslide monitoring. Landslide is a phenomenon and disaster triggered by natural and artificial reasons that a part of slope comprised of rock, soil and other fragmental materials slide alone a certain weak structural surface under the gravitation. Consequently, according to the geo-science principle of landslide, there is an obvious change in the sliding region between the pre-landslide and post-landslide, and it can be described in remote sensing imagery, so we develop the new approach to identify landslides, which uses change detection based on texture analysis in multi-temporal imageries. Preprocessing the remote sensing data including the following aspects of image enhancement and filtering, smoothing and cutting, image mosaics, registration and merge, geometric correction and radiation calibration, this paper does change detection base on texture characteristics in multi-temporal images to recognize landslide automatically. After change detection of multi-temporal remote sensing images based on texture analysis, if there is no change in remote sensing image, the image detected is relatively homogeneous, the image detected shows some clustering characteristics; if there is part change in image, the image detected will show two or more clustering centers; if there is complete change in remote sensing image, the image detected will show disorderly and unsystematic. At last, this

  9. Deviation from Power Law Behavior in Landslide Phenomenon

    NASA Astrophysics Data System (ADS)

    Li, L.; Lan, H.; Wu, Y.

    2013-12-01

    Power law distribution of magnitude is widely observed in many natural hazards (e.g., earthquake, floods, tornadoes, and forest fires). Landslide is unique as the size distribution of landslide is characterized by a power law decrease with a rollover in the small size end. Yet, the emergence of the rollover, i.e., the deviation from power law behavior for small size landslides, remains a mystery. In this contribution, we grouped the forces applied on landslide bodies into two categories: 1) the forces proportional to the volume of failure mass (gravity and friction), and 2) the forces proportional to the area of failure surface (cohesion). Failure occurs when the forces proportional to volume exceed the forces proportional to surface area. As such, given a certain mechanical configuration, the failure volume to failure surface area ratio must exceed a corresponding threshold to guarantee a failure. Assuming all landslides share a uniform shape, which means the volume to surface area ratio of landslide regularly increase with the landslide volume, a cutoff of landslide volume distribution in the small size end can be defined. However, in realistic landslide phenomena, where heterogeneities of landslide shape and mechanical configuration are existent, a simple cutoff of landslide volume distribution does not exist. The stochasticity of landslide shape introduce a probability distribution of the volume to surface area ratio with regard to landslide volume, with which the probability that the volume to surface ratio exceed the threshold can be estimated regarding values of landslide volume. An experiment based on empirical data showed that this probability can induce the power law distribution of landslide volume roll down in the small size end. We therefore proposed that the constraints on the failure volume to failure surface area ratio together with the heterogeneity of landslide geometry and mechanical configuration attribute for the deviation from power law

  10. Layers, Landslides, and Sand Dunes

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 27 October 2003

    This image shows the northern rim of one of the Valles Marineris canyons. Careful inspection shows many interesting features here. Note that the spurs and gullies in the canyon wall disappear some distance below the top of the canyon wall, indicating the presence of some smooth material here that weathers differently from the underlying rocks. On the floor of the canyon, there are remains from a landslide that came hurtling down the canyon wall between two spurs. Riding over the topography of the canyon floor are many large sand dunes, migrating generally from the lower right to upper left.

    Image information: VIS instrument. Latitude -14.1, Longitude 306.7 East (53.3 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. Landslide Prediction Study in Malaysia

    NASA Astrophysics Data System (ADS)

    Koay, Swee Peng; Lateh, Habibah; Murakami, Satoshi; Koyama, Tomofumi; Sakai, Naoki; Jamaludin, Suhaimi

    2014-05-01

    In Malaysia, landslides are occurring more often than before. The Malaysian Government allocates millions of Malaysian Ringgit for slope monitoring and slope failure measurement in the budget every year. In rural areas, local authorities also play a major role in monitoring the slope to prevent casualty. However, there are thousands of slopes which are classified as dangerous slopes. Implementing site monitoring system in these slopes, with extensometers, soil moisture probes, inclinometers and water gauges, to monitor the movement of the soil in the slopes and predict the occurrence of slopes failure, are too costly and almost impossible. Here, two snake curve methods, Accumulated Rainfall vs. Rainfall Intensity Method and Working Rainfall vs. Rainfall Intensity Method, for the slope failure prediction are proposed. In Accumulated Rainfall vs. Rainfall Intensity Method, Accumulated Rainfall is defined as RN = δΣ t=1Nrt, where RN is the accumulated rain from t = 1 to N , and will be reset to 0 if the rain stop period is longer than the period of water table drawdown to pre-rain level. Rainfall Intensity is hourly rainfall. The definition of Working Rainfall, in Working Rainfall vs. Rainfall Intensity Method, is Rw = rt + δΣ n=1Nαt-n · rt-n , where rt is the volume of rainfall in tth. hour, rt-n is the volume of rainfall in (t -n)th. hour and r0 = 0, at-n is the reduction factor defined as follows, αt-n = 0.5n/ T, where T is a half-life period (in hours), and N < t . If at-n

  12. A regional inventory of the landslide processes and the elements at risk on the Rift flanks west of Lake Kivu (DRC)

    NASA Astrophysics Data System (ADS)

    Maki Mateso, Jean-Claude; Monsieurs, Elise; Jacobs, Liesbet; Bagalwa Mateso, Luc; Fiama Bondo, Silvanos; Delvaux, Damien; Albino, Fabien; Kervyn, François; Dewitte, Olivier

    2016-04-01

    The Rift flanks west of Lake Kivu (DRC) are one of the Congolese regions most affected by fatal landslides. However, information on the distribution of these processes and their impact on society is still lacking. Here we present a first regional landslide inventory and the associated elements at risk. The inventory was conducted in an area of 5,700 km² in three administrative territories between the cities of Bukavu and Goma. The region is one of the most densely populated area of DRC with a density of up to 200 persons/km². The approach for the inventory relies on visual analysis of Google Earth imagery and a 5 m resolution DEM that we produced from TanDEM-X interferometry. Field validation was performed in target places accounting for 5% of the study area. More than 2,000 landslides were mapped and distinction was made between deep and shallow, and slide and flow processes. Average landslide area is 6 ha (max. = 430 ha). Geomorphological analysis of landslide distribution shows topographic, lithologic, climatic and seismic controls. For 600 randomly-selected landslides, elements at risk (house, road, cultivated land, river) were inventoried in the areas affected and potentially affected by the instabilities; 10% of the landslides are inhabited and 25% do not present any risk. Numerous landslides have caused direct and indirect damage in recent years. In some places, the impact of mining activities on slope stability can be important. Google Earth was the only way to locate the recent shallow failures triggered by known extreme rainfall events. This inventory is a first step towards the understanding of the landslide processes in the region. Further studies are needed to complete and validate the information, to better infer about the triggers, and to compute susceptibility and risk maps.

  13. Landslide inventory development in a data sparse region: spatial and temporal characteristics of landslides in Papua New Guinea

    NASA Astrophysics Data System (ADS)

    Robbins, J. C.; Petterson, M. G.

    2015-08-01

    In Papua New Guinea (PNG) earthquakes and rainfall events form the dominant trigger mechanisms capable of generating many landslides. Large volume and high density landsliding can result in significant socio-economic impacts, which are felt particularly strongly in the largely subsistence-orientated communities which reside in the most susceptible areas of the country. As PNG has undergone rapid development and increased external investment from mining and other companies, population and settled areas have increased, hence the potential for damage from landslides has also increased. Information on the spatial and temporal distribution of landslides, at a regional-scale, is critical for developing landslide hazard maps and for planning, sustainable development and decision making. This study describes the methods used to produce the first, country-wide landslide inventory for PNG and analyses of landslide events which occurred between 1970 and 2013. The findings illustrate that there is a strong climatic control on landslide-triggering events and that the majority (~ 61 %) of landslides in the PNG landslide inventory are initiated by rainfall related triggers. There is also large year to year variability in the annual occurrence of landslide events and this is related to the phase of El Niño Southern Oscillation (ENSO) and mesoscale rainfall variability. Landslide-triggering events occur during the north-westerly monsoon season during all phases of ENSO, but less landslide-triggering events are observed during drier season months (May to October) during El Niño phases, than either La Niña or ENSO neutral periods. This analysis has identified landslide hazard hotspots and relationships between landslide occurrence and rainfall climatology and this information can prove to be very valuable in the assessment of trends and future behaviour, which can be useful for policy makers and planners.

  14. Landslides hazard mapping integrating remote sensing and geo-morphological data in the Sorrentina Peninsula coastal areas

    NASA Astrophysics Data System (ADS)

    spinetti, claudia; bisson, marina; tolomei, cristiano; colini, laura; galvani, alessandro; moro, marco; saroli, michele; sepe, vincenzo

    2016-04-01

    The densely inhabited Campania region (Southern Italy) is affected by numerous and dangerous landslides. In particular, the coastal area of Sorrentina Peninsula is one of the zones most subjected to two types of landslides: volcanoclastic debris flows and rock fall. The first type occurs during intensive or persistent precipitations and on significant hillslopes where carbonatic bedrock is covered by pyroclastic deposits related to the Somma-Vesuvius and Phlegrean Fields explosive activity. The second type could be triggered by seismic events and occurs in areas where outcropping bedrock with steep slopes (e.g. the cliffs) is subjected to coastal erosion generating cliff instability. In order to improve the landslides hazard zonation in the Sorrentina Peninsula coastal area, we show a multidisciplinary approach to identify the areas more prone to generate such types of landslide. Our approach involves the analyses of ERS (temporal span between 1992-2000), Envisat (2003-2010), and COSMO-SkyMed (2013-2015) SAR data elaborated applying multi-temporal InSAR techniques to obtain the ground displacement maps and the relative displacement time series, integrated by means of GPS data. These maps were used to identify the instability areas and subsequently investigated by field survey, airborne photogeological interpretation and morphometric elaborations derived from airborne Lidar information. In addition, the land cover mapping was obtained using satellite high-medium resolution data. The analysis was performed in a GIS environment allowing to identify the main parameters that influence the slope instability and to obtain the landslide hazard map. finally, the comparison with the landslides historical database provides the different landslides susceptibility degrees classes.

  15. Estimating the empirical probability of submarine landslide occurrence

    USGS Publications Warehouse

    Geist, Eric L.; Parsons, Thomas E.

    2010-01-01

    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.

  16. Databases and GIS for landslide research in Europe

    NASA Astrophysics Data System (ADS)

    Dikau, Richard; Cavallin, Angelo; Jäger, Stefan

    1996-04-01

    Within the project "The Temporal occurrence and forecasting of landslides in the European Community" a review of the use of databases and GIS for landslide research has been accomplished. It shows a high potential of these techniques in storing spatial and temporal landslide data (landslide inventories) and in applying different modelling approaches to landslide hazard assessments at various scales. There are three major strategies in European landslide research using GIS and database technologies. At medium and broad scales different combinations of landslide data with factor maps (e.g. slope angle, lithology and geomorphological units) lead to static susceptibility and hazard assessments, which allow probability evaluations for future landslide occurrences. At local scales process models to simulate trajectories of paths for slope processes and deterministic slope stability models are in use. In landslide frequency analysis, temporal database information are correlated with recent and historical triggering factors (e.g. precipitation and precipitation indices) to calculate temporal probabilities for landslide forecasting. However, despite encouraging progress in applying computer technologies in European landslide research, the potential of these tools is still largely untested. Furthermore, it is clear that sophisticated technology cannot replace field work, interdisciplinary research strategies, and critical testing of the reliability of the model results.

  17. Influence of surface-normal ground acceleration on the initiation of the Jih-Feng-Erh-Shan landslide during the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Huang, C.-C.; Lee, Y.-H.; Liu, Huaibao P.; Keefer, D.K.; Jibson, R.W.

    2001-01-01

    The 1999 Chi-Chi, Taiwan, earthquake triggered numerous landslides throughout a large area in the Central Range, to the east, southeast, and south of the fault rupture. Among them are two large rock avalanches, at Tsaoling and at Jih-Feng-Erh-Shan. At Jih-Feng-Erh-Shan, the entire thickness (30-50 m) of the Miocene Changhukeng Shale over an area of 1 km2 slid down its bedding plane for a distance of about 1 km. Initial movement of the landslide was nearly purely translational. We investigate the effect of surface-normal acceleration on the initiation of the Jih-Feng-Erh-Shan landslide using a block slide model. We show that this acceleration, currently not considered by dynamic slope-stability analysis methods, significantly influences the initiation of the landslide.

  18. The impact of systematically incomplete and positionally inaccurate landslide inventories on statistical landslide susceptibility models

    NASA Astrophysics Data System (ADS)

    Steger, Stefan; Brenning, Alexander; Bell, Rainer; Glade, Thomas

    2016-04-01

    Several publications emphasize that the quality of statistical landslide susceptibility maps is highly dependent on the completeness and positional accuracy of the landslide inventory used as a response variable to produce the underlying models. We assume that erroneous landslide inventories distort relationships between a landslide inventory and its predictors while we hypothesize that the predictive performance of the underlying models is not necessarily worse in comparison to models generated with an accurate and unbiased landslide inventory. The objective of this study was to investigate the effect of incomplete and positionally inaccurate landslide inventories on the results of statistical landslide susceptibility models. An additional aim was to explore the potential of applying multilevel models to tackle the problem of confounded model coefficients as a results of inventory-based biases. The study was conducted for a landslide-prone study area (100 km²) located in the western part of Lower Austria. An accurate earth-slide point inventory (n = 591) was available for that region. The methodological approach consisted of an artificial introduction of biases and positional inaccuracies into the present landslide inventory and a subsequent quantitative (odds ratios, variable importance, non-spatial and spatial cross validation) and qualitative (geomorphic plausibility) evaluation of the modelling results. Two mapping biases were introduced separately by gradually thinning landslide data (0%, 20%, 80%) within (i) forested areas and (ii) selected municipalities. Positional inaccuracies were simulated by gradually changing the original landslide position (0, 5, 10, 20, 50 and 120 m). The resulting inventories were introduced into a logistic regression model while we considered the effects of including or excluding predictors directly related to the respective incompleteness. All incomplete inventories were additionally introduced into a two-level generalized

  19. Climate change has limited impact on soil-mantled landsliding

    NASA Astrophysics Data System (ADS)

    Parker, Robert; Hales, Tristram; Mudd, Simon; Grieve, Stuart

    2015-04-01

    Projected increases in future storminess, associated with anthropogenically-driven climate change, are expected to produce an increase in landslide frequency and hazards. This prediction relies on an implicit and poorly tested assumption, that landslide frequency is limited by the effectiveness of landslide triggers (pore-pressure events determined by the intensity and duration of storms). Using an unprecedented field dataset of hillslope soil depths and ages (attained through radiocarbon dating) from the Southern Appalachian Mountains (USA), we show that this assumption is not valid in this landscape. Instead, landslide frequency is limited by rates of soil production and transport processes, which prepare sites for future landsliding. By simulating the evolution of Appalachian hillslopes, we demonstrate that unless climate change can drive an increase in soil production and transport rates, an increase in future storminess will have little effect on long-term landslide frequency, while individual storms will trigger fewer and smaller landslides.

  20. Analysis of national and regional landslide inventories in Europe

    NASA Astrophysics Data System (ADS)

    Hervás, J.; Van Den Eeckhaut, M.

    2012-04-01

    A landslide inventory can be defined as a detailed register of the distribution and characteristics of past landslides in an area. Today most landslide inventories have the form of digital databases including landslide distribution maps and associated alphanumeric information for each landslide. While landslide inventories are of the utmost importance for land use planning and risk management through the generation of landslide zonation (susceptibility, hazard and risk) maps, landslide databases are thought to greatly differ from one country to another and often also within the same country. This hampers the generation of comparable, harmonised landslide zonation maps at national and continental scales, which is needed for policy and decision making at EU level as regarded for instance in the INSPIRE Directive and the Thematic Strategy for Soil Protection. In order to have a clear understanding of the landslide inventories available in Europe and their potential to produce landslide zonation maps as well as to draw recommendations to improve harmonisation and interoperability between landslide databases, we have surveyed 37 countries. In total, information has been collected and analysed for 24 national databases in 22 countries (Albania, Andorra, Austria, Bosnia and Herzegovina, Bulgaria, Czech Republic, Former Yugoslav Republic of Macedonia, France, Greece, Hungary, Iceland, Ireland, Italy, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and UK) and 22 regional databases in 10 countries. At the moment, over 633,000 landslides are recorded in national databases, representing on average less than 50% of the estimated landslides occurred in these countries. The sample of regional databases included over 103,000 landslides, with an estimated completeness substantially higher than that of national databases, as more attention can be paid for data collection over smaller regions. Yet, both for national and regional coverage, the data collection

  1. Tien Shan Geohazards Database: Earthquakes and landslides

    NASA Astrophysics Data System (ADS)

    Havenith, H. B.; Strom, A.; Torgoev, I.; Torgoev, A.; Lamair, L.; Ischuk, A.; Abdrakhmatov, K.

    2015-11-01

    In this paper we present new and review already existing landslide and earthquake data for a large part of the Tien Shan, Central Asia. For the same area, only partial databases for sub-regions have been presented previously. They were compiled and new data were added to fill the gaps between the databases. Major new inputs are products of the Central Asia Seismic Risk Initiative (CASRI): a tentative digital map of active faults (even with indication of characteristic or possible maximum magnitude) and the earthquake catalogue of Central Asia until 2009 that was now updated with USGS data (to May 2014). The new compiled landslide inventory contains existing records of 1600 previously mapped mass movements and more than 1800 new landslide data. Considering presently available seismo-tectonic and landslide data, a target region of 1200 km (E-W) by 600 km (N-S) was defined for the production of more or less continuous geohazards information. This target region includes the entire Kyrgyz Tien Shan, the South-Western Tien Shan in Tajikistan, the Fergana Basin (Kyrgyzstan, Tajikistan and Uzbekistan) as well as the Western part in Uzbekistan, the North-Easternmost part in Kazakhstan and a small part of the Eastern Chinese Tien Shan (for the zones outside Kyrgyzstan and Tajikistan, only limited information was available and compiled). On the basis of the new landslide inventory and the updated earthquake catalogue, the link between landslide and earthquake activity is analysed. First, size-frequency relationships are studied for both types of geohazards, in terms of Gutenberg-Richter Law for the earthquakes and in terms of probability density function for the landslides. For several regions and major earthquake events, case histories are presented to outline further the close connection between earthquake and landslide hazards in the Tien Shan. From this study, we concluded first that a major hazard component is still now insufficiently known for both types of geohazards

  2. Landslide inventory map as a tool for landscape planning and management in Buzau Land Geopark

    NASA Astrophysics Data System (ADS)

    Tatu, Mihai; Niculae, Lucica; Popa, Răzvan-Gabriel

    2015-04-01

    Buzău Land is an aspiring Geopark in Romania, located in the mountainous region of the southern part of the Carpathian Bend Area. From a geologic point of view, the East Carpathians represent a segment of the Alpine - Carpathian orogene, and they are composed of numerous tectonic units put up throughout the Mesozoic and Cenozoic orogenesis. They represent a result of two compressional phases, (1) during Late Cretaceous and (2) during Early and Middle Miocene that were responsible for thrusting of internal units onto external units. The latter cover tectonically the Foredeep folded deposits. Landslides are one of the most widespread and dangerous natural hazards in this region, disrupting access routes and damaging property and habitats at least twice per year, in the rainy seasons. This hazard induces deep changes in the landscape and has serious economic consequences related to the damaging of infrastructure and isolation of localities. The proximity to the Vrancea seismogenic zone increases the risk of landslide triggering. A first step in observing the space and time tendency and amplitude of landslides, in order to distinguish the main vulnerabilities and estimate the risk, is to produce an inventory map. We shall present a landslide inventory map for the Buzău Land territory (~1036 km2), which is the primary base of information for further discussions regarding this phenomenon and an essential tool in observing the development of mass-wasting processes and in landscape planning. The inventory map is in accordance with the recommendations of the IAEG Commission on Landslides and other Mass-Movement, applied across the EU. Based on this work, we can already draw some remarks: - The Geopark territory mostly covers two major tectonic units of the East Carpathians: the external nappes and the folded foredeep; areas with landslide potential are common, but by far the highest landslide frequency is observed in the foredeep. This is related to the soft, argillaceous

  3. Improving Landslide Inventories by Limiting Land Classification to Drainage Areas of Debris Flow-Dominated Channels

    NASA Astrophysics Data System (ADS)

    Lyons, N. J.; Mitasova, H.; Wegmann, K. W.

    2011-12-01

    classification inputs is extracted from a lidar-derived digital elevation model with a resolution of 4 m. A normalized difference vegetation index map created from an aerial photograph is also used as a classification input as a surrogate of vegetation canopy thickness. A map of debris flow candidates is produced by multi-resolution, contextual segmentation and classification and is compared to a previously published API landslide inventory of GSMNP. 67% of debris flows are identified and 79% of the land surface is correctly classified when the algorithm is limited to areas that drain to debris flow dominated channels. Candidates in this map include numerous features that have similar characteristics as debris flows delineated in the API inventory. When the entire study area is included, 60% of debris flows are identified and 61% of the land surface is correctly classified. This inventorying method, while limited to one landslide type, allows for a focused approach to statistically characterize the land surface and results in more accurate landslide identification in this study area of the automated techniques. Future work will expand this technique's utility to landslide terrain in different physiographic settings and include field verification of the previously unmapped landslide areas.

  4. Analysis of Landslide Hazard Impact Using the Landslide Database for Germany

    NASA Astrophysics Data System (ADS)

    Klose, M.; Damm, B.

    2014-12-01

    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.

  5. Landslide Susceptibility Statistical Methods: A Critical and Systematic Literature Review

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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

  6. Probabilistic assessment of precipitation-triggered landslides using historical records of landslide occurence, Seattle, Washington

    USGS Publications Warehouse

    Coe, J.A.; Michael, J.A.; Crovelli, R.A.; Savage, W.Z.; Laprade, W.T.; Nashem, W.D.

    2004-01-01

    Ninety years of historical landslide records were used as input to the Poisson and binomial probability models. Results from these models show that, for precipitation-triggered landslides, approximately 9 percent of the area of Seattle has annual exceedance probabilities of 1 percent or greater. Application of the Poisson model for estimating the future occurrence of individual landslides results in a worst-case scenario map, with a maximum annual exceedance probability of 25 percent on a hillslope near Duwamish Head in West Seattle. Application of the binomial model for estimating the future occurrence of a year with one or more landslides results in a map with a maximum annual exceedance probability of 17 percent (also near Duwamish Head). Slope and geology both play a role in localizing the occurrence of landslides in Seattle. A positive correlation exists between slope and mean exceedance probability, with probability tending to increase as slope increases. Sixty-four percent of all historical landslide locations are within 150 m (500 ft, horizontal distance) of the Esperance Sand/Lawton Clay contact, but within this zone, no positive or negative correlation exists between exceedance probability and distance to the contact.

  7. The influence of anisotropy on preferential flow in landslides

    NASA Astrophysics Data System (ADS)

    Cristiano, Elena; Barontini, Stefano; Bogaard, Thom A.; Shao, Wei

    2015-04-01

    Infiltration is one of the most important landslides triggering mechanisms and it is controlled by the hydraulic characteristics of the soil, which depends on the degree of saturation, the existence of preferential flow paths and by anisotropy. Many soils, indeed, exhibit a certain degree of anisotropy due to the stratification associated with soil forming process. Recently, various authors investigated the effect of rainfall in layered soils and its effect on rainfall triggered landslides by means of experimental, conceptual, numerical and theoretical approaches. However, the combined effect of anisotropy and preferential flow on infiltration process and related to rainfall induced landslides has, according to the authors best knowledge, not been studied yet. Aiming at better understanding the soil hydrological processes which take place during an infiltration process, the stability of a synthetic hill slope is numerically investigated. The geometry we considered for the model is a slope with two different layers: the upper soil layer consists of sandy loam, while the lower soil layer is made out of clay. The geometry was studied using both a single permeability and a dual permeability model. In the first case the hydraulic conductivity at saturation was considered isotropic, equal in all directions. Then the vertical component of the hydraulic conductivity tensor at saturation was reduced, while in the third scenario the horizontal component was reduced. In this way the anisotropy effects on both the principal directions were studied. In the dual permeability model, the influence of the anisotropy was considered only in the preferential flow domain, and the hydraulic conductivity at saturation of the soil matrix domain was defined as being isotropic. In order to evaluate also the effects of rainfall intensity on the slope, two different rainfall events were studied: a low intensity rainfall with a long time duration (2 mmh-1,150 h) and an high intensity rainfall

  8. Effects of land-use changes on landslides in a landslide-prone area (Ardesen, Rize, NE Turkey).

    PubMed

    Karsli, F; Atasoy, M; Yalcin, A; Reis, S; Demir, O; Gokceoglu, C

    2009-09-01

    Various natural hazards such as landslides, avalanches, floods and debris flows can result in enormous property damages and human casualties in Eastern Black Sea region of Turkey. Mountainous topographic character and high frequency of heavy rain are the main factors for landslide occurrence in Ardesen, Rize. For this reason, the main target of the present study is to evaluate the landslide hazards using a sequence of historical aerial photographs in Ardesen (Rize), Turkey, by Photogrammetry and Geographical Information System (GIS). Landslide locations in the study area were identified by interpretation of aerial photographs dated in 1973 and 2002, and by field surveys. In the study, the selected factors conditioning landslides are lithology, slope gradient, slope aspect, vegetation cover, land class, climate, rainfall and proximity to roads. These factors were considered as effective on the occurrence of landslides. The areas under landslide threat were analyzed and mapped considering the landslide conditioning factors. Some of the conditioning factors were investigated and estimated by employing visual interpretation of aerial photos and topographic data. The results showed that the slope, lithology, terrain roughness, proximity to roads, and the cover type played important roles on landslide occurrence. The results also showed that degree of landslides was affected by the number of houses constructed in the region. As a consequence, the method employed in the study provides important benefits for landslide hazard mitigation efforts, because a combination of both photogrammetric techniques and GIS is presented. PMID:18780152

  9. An unusual landslide feature on Mars

    NASA Technical Reports Server (NTRS)

    Veverka, J.; Liang, T.

    1975-01-01

    A flow feature on a crater wall, characteristic of a landslide, has been identified in a Mariner 9 high resolution photograph. Although other evidence of mass wasting is common in Mariner 9 photography, the case presented appears unique. A tentative conclusion is that, at least in some cases, Martian soil exhibits significant internal friction in mass movements.

  10. Landslide risk models for decision making.

    PubMed

    Bonachea, Jaime; Remondo, Juan; de Terán, José Ramón Díaz; González-Díez, Alberto; Cendrero, Antonio

    2009-11-01

    This contribution presents a quantitative procedure for landslide risk analysis and zoning considering hazard, exposure (or value of elements at risk), and vulnerability. The method provides the means to obtain landslide risk models (expressing expected damage due to landslides on material elements and economic activities in monetary terms, according to different scenarios and periods) useful to identify areas where mitigation efforts will be most cost effective. It allows identifying priority areas for the implementation of actions to reduce vulnerability (elements) or hazard (processes). The procedure proposed can also be used as a preventive tool, through its application to strategic environmental impact analysis (SEIA) of land-use plans. The underlying hypothesis is that reliable predictions about hazard and risk can be made using models based on a detailed analysis of past landslide occurrences in connection with conditioning factors and data on past damage. The results show that the approach proposed and the hypothesis formulated are essentially correct, providing estimates of the order of magnitude of expected losses for a given time period. Uncertainties, strengths, and shortcomings of the procedure and results obtained are discussed and potential lines of research to improve the models are indicated. Finally, comments and suggestions are provided to generalize this type of analysis. PMID:19732396

  11. AschFlow - A dynamic landslide run-out model for medium scale hazard analysis.

    NASA Astrophysics Data System (ADS)

    Luna, Byron Quan; Blahut, Jan; van Asch, Theo; van Westen, Cees; Kappes, Melanie

    2015-04-01

    Landslides and debris flow hazard assessments require a scale-dependent analysis in order to mitigate damage and other negative consequences at the respective scales of occurrence. Medium or large scale landslide run-out modelling for many possible landslide initiation areas has been a cumbersome task in the past. This arises from the difficulty to precisely define the location and volume of the released mass and from the inability of the run-out models to compute the displacement with a large amount of individual initiation areas (computational exhaustive). Most of the existing physically based run-out models have complications in handling such situations and therefore empirical methods have been used as a practical mean to predict landslides mobility at a medium scale (1:10,000 to 1:50,000). In this context, a simple medium scale numerical model for rapid mass movements in urban and mountainous areas was developed. The deterministic nature of the approach makes it possible to calculate the velocity, height and increase in mass by erosion, resulting in the estimation of various forms of impacts exerted by debris flows at the medium scale The established and implemented model ("AschFlow") is a 2-D one-phase continuum model that simulates, the entrainment, spreading and deposition process of a landslide or debris flow at a medium scale. The flow is thus treated as a single phase material, whose behavior is controlled by rheology (e.g. Voellmy or Bingham). The developed regional model "AschFlow" was applied and evaluated in well documented areas with known past debris flow events.

  12. Extracting source characteristics and dynamics of the August 2010 Mount Meager landslide from broadband seismograms

    NASA Astrophysics Data System (ADS)

    Allstadt, Kate

    2013-09-01

    methods can substantially improve the characterization of the dynamics of large and rapid landslides. Such landslides often generate strong long-period seismic waves due to the large-scale acceleration of the entire landslide mass, which, according to theory, can be approximated as a single-force mechanism at long wavelengths. I apply this theory and invert the long-period seismic waves generated by the 48.5 Mm3 August 2010 Mount Meager rockslide-debris flow in British Columbia. Using data from five broadband seismic stations 70 to 276 km from the source, I obtain a time series of forces the landslide exerted on the Earth, with peak forces of 1.0 × 1011 N. The direction and amplitude of the forces can be used to determine the timing and occurrence of events and subevents. Using this result, in combination with other field and geospatial evidence, I calculate an average horizontal acceleration of the rockslide of 0.39 m/s2 and an average apparent coefficient of basal friction of 0.38 ± 0.02, which suggests elevated basal fluid pressures. The direction and timing of the strongest forces are consistent with the centripetal acceleration of the debris flow around corners in its path. I use this correlation to estimate speeds, which peak at 92 m/s. This study demonstrates that the time series recording of forces exerted by a large and rapid landslide derived remotely from seismic records can be used to tie post-slide evidence to what actually occurred during the event and can serve to validate numerical models and theoretical methods.

  13. Shallow Landslides Hazards in a Changing Climate

    NASA Astrophysics Data System (ADS)

    Bellugi, D. G.; Perron, J. T.; O'Gorman, P. A.; Milledge, D.

    2015-12-01

    Rainfall-triggered shallow landslides pose hazards to communities, infrastructure, and ecosystems. The magnitude and frequency of extreme precipitation are expected to change under climate warming, but their effects on landslide abundance, size, and spatial distribution are poorly understood. Fractional changes in extreme precipitation can be considerably greater than those in mean precipitation as storm intensity is not constrained by the atmospheric energy budget. Changes in orographic precipitation may also alter the spatial pattern of extreme precipitation. We assess relative changes in extreme precipitation for varying return periods and event durations predicted by regional climate models (RCM) in the USA over the periods 1971-2000 to 2041-2070. We delineate areas where orographic precipitation contributes to changes in extreme precipitation by analyzing topography and local winds associated with these extremes. To verify that RCMs reflect theoretical predictions, we quantify precipitation changes on the lee and windward slopes. We assess impacts of extreme precipitation change on landslide characteristics by applying a search algorithm that predicts landslide abundance, location, and size to a study site in the Oregon Coast Range (OCR) with a 10-year landslide observational record. We test a range of precipitation scenarios, forest management practices, and antecedent moisture conditions. To explore effects of orographic precipitation, we rescale observed precipitation for representative lee and windward locations and find that fractional changes in mean winter precipitation are ~3 times larger on leeward slopes. The fractional changes in intensity are much greater for extreme precipitation than mean precipitation, and they increase with return period. In the Pacific Northwest, leeward increases are ~10% for 2-year events and ~20% for 30-year events. At our study site, a 20% increase in precipitation or antecedent moisture corresponds to a 30-40% increase in

  14. Landslides and impacts on comets.

    NASA Astrophysics Data System (ADS)

    Czechowski, Leszek

    2016-07-01

    The recent landing of Philae on the comet 67P/Czuriumow-Gierasimienko indicates that elastic properties of comet's nuclei could be similar to elastic properties of dry snow, namely Young modulus is assumed to be 106 - 108 Pa. We considered a simple model of two spheres (with radius 1400 m each) connected by cylinder (with radius of 200 m and length of 200 m). Density is 470 kg m-3. This shape corresponds approximately to shape of some comets. A few vibration modes are possible. In present research we consider 3 modes: bending, lengthening-shortening along axis of symmetry, and torsion. Let assume that comets are hit by small meteoroid of the mass of 1 kg and velocity 20 km s-1. The maximum values of acceleration of the surface resulting from this impact are given in Table 1. Note that these values are higher than acceleration of the gravity of the comet. Consequently, these vibrations could be an important factor of surface evolution, e.g. they could trigger landslides. It could be alternative mechanism to that presented in [4] (i.e. fluidization). Acknowledgement: The research is partly supported by Polish National Science Centre (decision 2014/15/B/ST 10/02117) References [1] T. Spohn, J. Knollenberg, A. J. Ball, M. Ba-naszkiewicz, J. Benkhoff, M. Grott, J. Gry-gorczuk, C. Hüttig, A. Hagermann, G. Kargl, E. Kaufmann, N. Kömle, E. Kührt, K. J. Kossacki, W. Marczewski, I. Pelivan, R. Schrödter, K. Seiferlin. (2015) Thermal and mechanical properties of the near-surface layers of comet 67P/Churyumov- Gera-simenko Science 31 July 2015: Vol. 349 no. 6247 DOI: 10.1126/science.aab0464 [2] Reuter B. (2013) On how to measure snow mechanical properties relevant to slab avalanche release. International Snow Science Workshop Grenoble - Chamonix Mont-Blanc - 2013 007 [3] Ball A.J. (1997) Ph. D. Thesis: Measuring Physical Properties at the Surface of a Comet Nu-cleus, Univ.of Kent U.K. [4] Belton M. J.S., Melosh J. (2009). Fluidization and multiphase transport of

  15. La Conchita Landslide Risk Assessment

    NASA Astrophysics Data System (ADS)

    Kropp, A.; Johnson, L.; Magnusen, W.; Hitchcock, C. S.

    2009-12-01

    Following the disastrous landslide in La Conchita in 2005 that resulted in ten deaths, the State of California selected our team to prepare a risk assessment for a committee of key stakeholders. The stakeholders represented the State of California, Ventura County, members of the La Conchita community, the railroad, and the upslope ranch owner (where the slide originated); a group with widely varying views and interests. Our team was charged with characterizing the major hazards, developing a series of mitigation concepts, evaluating the benefits and costs of mitigation, and gathering stakeholder input throughout the process. Two unique elements of the study were the methodologies utilized for the consequence assessment and for the decision-making framework. La Conchita is exposed to multiple slope hazards, each with differing geographical distributions, as well as depth and velocity characteristics. Three consequence matrices were developed so that the potential financial losses, structural vulnerabilities, and human safety exposure could be evaluated. The matrices utilized semi-quantitative loss evaluations (both financial and life safety) based on a generalized understanding of likely vulnerability and hazard characteristics. The model provided a quantitative estimate of cumulative losses over a 50-year period, including losses of life based on FEMA evaluation criteria. Conceptual mitigation options and loss estimates were developed to provide a range of risk management solutions that were feasible from a cost-benefit standpoint. A decision tree approach was adopted to focus on fundamental risk management questions rather than on specific outcomes since the committee did not have a consensus view on the preferred solution. These questions included: 1. Over what time period can risks be tolerated before implementation of decisions? 2. Whose responsibility is it to identify a workable risk management solution? 3. Who will own the project? The decision tree

  16. Back Analysis of the 2014 San Leo Landslide Using Combined Terrestrial Laser Scanning and 3D Distinct Element Modelling

    NASA Astrophysics Data System (ADS)

    Spreafico, Margherita Cecilia; Francioni, Mirko; Cervi, Federico; Stead, Doug; Bitelli, Gabriele; Ghirotti, Monica; Girelli, Valentina Alena; Lucente, Claudio Corrado; Tini, Maria Alessandra; Borgatti, Lisa

    2016-06-01

    Landslides of the lateral spreading type, involving brittle geological units overlying ductile terrains, are a common occurrence in the sandstone and limestone plateaux of the northern Apennines of Italy. The edges of these plateaux are often the location of rapid landslide phenomena, such as rock slides, rock falls and topples. In this paper, we present a back analysis of a recent landslide (February 2014), involving the north-eastern sector of the San Leo rock slab (northern Apennines, Emilia-Romagna Region) which is a representative example of this type of phenomena. The aquifer hosted in the fractured slab, due to its relatively higher secondary permeability in comparison to the lower clayey units leads to the development of perennial and ephemeral springs at the contact between the two units. The related piping erosion phenomena, together with slope processes in the clay-shales have led to the progressive undermining of the slab, eventually predisposing large-scale landslides. Stability analyses were conducted coupling terrestrial laser scanning (TLS) and distinct element methods (DEMs). TLS point clouds were analysed to determine the pre- and post-failure geometry, the extension of the detachment area and the joint network characteristics. The block dimensions in the landslide deposit were mapped and used to infer the spacing of the discontinuities for insertion into the numerical model. Three-dimensional distinct element simulations were conducted, with and without undermining of the rock slab. The analyses allowed an assessment of the role of the undermining, together with the presence of an almost vertical joint set, striking sub-parallel to the cliff orientation, on the development of the slope instability processes. Based on the TLS and on the numerical simulation results, an interpretation of the landslide mechanism is proposed.

  17. Dynamic process analysis for the initiation and movement of the Donghekou landslide-debris flow triggered by the Wenchuan earthquake

    NASA Astrophysics Data System (ADS)

    Zhou, Jia-wen; Cui, Peng; Yang, Xing-guo

    2013-10-01

    The Donghekou landslide-debris flow was a remarkable geological disaster triggered by the Wenchuan earthquake in 2008. The dynamic process of a rapid landslide-debris flow is very complicated and can be divided into two aspects: the slope dynamic response of the earthquake and the mass movement and accumulation process. A numerical method combined with a finite difference method (FDM) and discrete element method (DEM) for simulation of landslide-debris flow under seismic loading is presented. The FDM and DEM are coupled through the critical sliding surface, initiation time and velocity. The dynamic response of the slope is simulated by the finite difference method, and critical sliding surface is determined using the earthquake response spectrum method. The landslide initiation time and the velocity are determined by time-history analysis. The mass movement and accumulation process is simulated using the discrete element method. Simulation results demonstrate that the maximum amplification coefficient of dynamic acceleration for the Donghekou slope is approximately 3.909, the initiation time of landslide is approximately 6.0 s, and the average initial velocity of the sliding mass is approximately 0.85 m/s. The failure of the slope is the result of elevation-orientated amplification effect and the sliding mass triggered with a small initial velocity. The numerical simulated result of the maximum sliding velocity is approximately 66.35 m/s, and the mass is disintegrated rapidly because of collision and free fall. The landslide velocity decreases when the flowing mass reaches a lower slope angle and gradually comes to a stop, and the total travel distance is approximately 2400 m.

  18. Export of earthquake-triggered landslides in active mountain ranges: insights from 2D morphodynamic modelling.

    NASA Astrophysics Data System (ADS)

    Croissant, Thomas; Lague, Dimitri; Davy, Philippe; Steer, Philippe

    2016-04-01

    In active mountain ranges, large earthquakes (Mw > 5-6) trigger numerous landslides that impact river dynamics. These landslides bring local and sudden sediment piles that will be eroded and transported along the river network causing downstream changes in river geometry, transport capacity and erosion efficiency. The progressive removal of landslide materials has implications for downstream hazards management and also for understanding landscape dynamics at the timescale of the seismic cycle. The export time of landslide-derived sediments after large-magnitude earthquakes has been studied from suspended load measurements but a full understanding of the total process, including the coupling between sediment transfer and channel geometry change, still remains an issue. Note that the transport of small sediment pulses has been studied in the context of river restoration, but the magnitude of sediment pulses generated by landslides may make the problem different. Here, we study the export of large volumes (>106 m3) of sediments with the 2D hydro-morphodynamic model, Eros. This model uses a new hydrodynamic module that resolves a reduced form of the Saint-Venant equations with a particle method. It is coupled with a sediment transport and lateral and vertical erosion model. Eros accounts for the complex retroactions between sediment transport and fluvial geometry, with a stochastic description of the floods experienced by the river. Moreover, it is able to reproduce several features deemed necessary to study the evacuation of large sediment pulses, such as river regime modification (single-thread to multi-thread), river avulsion and aggradation, floods and bank erosion. Using a synthetic and simple topography we first present how granulometry, landslide volume and geometry, channel slope and flood frequency influence 1) the dominance of pulse advection vs. diffusion during its evacuation, 2) the pulse export time and 3) the remaining volume of sediment in the catchment

  19. Modeling Tsunamis from Potential Submarine Landslides in the Puerto Rico Region

    NASA Astrophysics Data System (ADS)

    Lopez, A. M.; Horrillo, J.; Huerfano Moreno, V. A.; Mercado, A.

    2012-12-01

    Evidence of submarine landslides found on high-resolution bathymetry around the Puerto Rico - Virgin Islands region indicate that tsunamis may have formed in the past, thus affecting coastal zones around Puerto Rico. Furthermore, it suggests that future submarine landslides in the vicinity are likely to occur in the future, resulting in destruction and devastation never seen before for coastal communities in Puerto Rico. With the presence of massive amphitheaters offshore along the northern Puerto Rico coast, and the most recent evidence of the October 11, 1918 tsunami along its northwestern coast, the threat to coastal communities is higher than previously thought. Submarine landslides progress through time as slopes reach their stability. With numerous processes leading to instabilities and subsequent failure, the possibility of experiencing new submarine landslides is real and thus require an assessment as to quantify potential sources, their dimensions, volumes, resulting tsunamis, and their effects onshore. As part of a project to produce evacuation maps from potential sources, the National Tsunami Hazards Mitigation Program funded the Puerto Rico Seismic Network to identify sources, run tsunami simulations and estimate inundation and run-up values. In addition to 15 past submarine landslides observed in the region's bathymetry, 5 scenarios of submarine landslides have been identified as potentially occurring in the future. Whether any or all of these potential case scenarios occur in the upcoming century is unknown, however, results from this study are critical to quantify their effects along coastal areas and therefore prepare communities for their occurrence. Three such cases lie along the northern offshore region, where the Arecibo and Loiza amphitheaters are found, an area where the geology favors such phenomenons. In contrast, the southern offshore region do not show a similar trend and thus seem unlikely to produce large events. We have used available

  20. Construction of 3-Dimensional Printed Ultrasound Phantoms With Wall-less Vessels.

    PubMed

    Nikitichev, Daniil I; Barburas, Anamaria; McPherson, Kirstie; Mari, Jean-Martial; West, Simeon J; Desjardins, Adrien E

    2016-06-01

    Ultrasound phantoms are invaluable as training tools for vascular access procedures. We developed ultrasound phantoms with wall-less vessels using 3-dimensional printed chambers. Agar was used as a soft tissue-mimicking material, and the wall-less vessels were created with rods that were retracted after the agar was set. The chambers had integrated luer connectors to allow for fluid injections with clinical syringes. Several variations on this design are presented, which include branched and stenotic vessels. The results show that 3-dimensional printing can be well suited to the construction of wall-less ultrasound phantoms, with designs that can be readily customized and shared electronically. PMID:27162278

  1. 3-Dimensional Terraced NAND (3D TNAND) Flash Memory-Stacked Version of Folded NAND Array

    NASA Astrophysics Data System (ADS)

    Kim, Yoon; Cho, Seongjae; Lee, Gil Sung; Park, Il Han; Lee, Jong Duk; Shin, Hyungcheol; Park, Byung-Gook

    We propose a 3-dimensional terraced NAND flash memory. It has a vertical channel so it is possible to make a long enough channel in 1F2 size. And it has 3-dimensional structure whose channel is connected vertically along with two stairs. So we can obtain high density as in the stacked array structure, without silicon stacking process. We can make NAND flash memory with 3F2 cell size. Using SILVACO ATLAS simulation, we study terraced NAND flash memory characteristics such as program, erase, and read. Also, its fabrication method is proposed.

  2. Magnetic topologies of coronal mass ejection events: Effects of 3-dimensional reconnection

    SciTech Connect

    Gosling, J.T.

    1995-09-01

    New magnetic loops formed in the corona following coronal mass ejection, CME, liftoffs provide strong evidence that magnetic reconnection commonly occurs within the magnetic ``legs`` of the departing CMEs. Such reconnection is inherently 3-dimensional and naturally produces CMEs having magnetic flux rope topologies. Sustained reconnection behind CMEs can produce a mixture of open and disconnected field lines threading the CMES. In contrast to the results of 2-dimensional reconnection. the disconnected field lines are attached to the outer heliosphere at both ends. A variety of solar and solar wind observations are consistent with the concept of sustained 3-dimensional reconnection within the magnetic legs of CMEs close to the Sun.

  3. Dosimetric Comparison Between 3-Dimensional Conformal and Robotic SBRT Treatment Plans for Accelerated Partial Breast Radiotherapy.

    PubMed

    Goggin, L M; Descovich, M; McGuinness, C; Shiao, S; Pouliot, J; Park, C

    2016-06-01

    Accelerated partial breast irradiation is an attractive alternative to conventional whole breast radiotherapy for selected patients. Recently, CyberKnife has emerged as a possible alternative to conventional techniques for accelerated partial breast irradiation. In this retrospective study, we present a dosimetric comparison between 3-dimensional conformal radiotherapy plans and CyberKnife plans using circular (Iris) and multi-leaf collimators. Nine patients who had undergone breast-conserving surgery followed by whole breast radiation were included in this retrospective study. The CyberKnife planning target volume (PTV) was defined as the lumpectomy cavity + 10 mm + 2 mm with prescription dose of 30 Gy in 5 fractions. Two sets of 3-dimensional conformal radiotherapy plans were created, one used the same definitions as described for CyberKnife and the second used the RTOG-0413 definition of the PTV: lumpectomy cavity + 15 mm + 10 mm with prescription dose of 38.5 Gy in 10 fractions. Using both PTV definitions allowed us to compare the dose delivery capabilities of each technology and to evaluate the advantage of CyberKnife tracking. For the dosimetric comparison using the same PTV margins, CyberKnife and 3-dimensional plans resulted in similar tumor coverage and dose to critical structures, with the exception of the lung V5%, which was significantly smaller for 3-dimensional conformal radiotherapy, 6.2% when compared to 39.4% for CyberKnife-Iris and 17.9% for CyberKnife-multi-leaf collimator. When the inability of 3-dimensional conformal radiotherapy to track motion is considered, the result increased to 25.6%. Both CyberKnife-Iris and CyberKnife-multi-leaf collimator plans demonstrated significantly lower average ipsilateral breast V50% (25.5% and 24.2%, respectively) than 3-dimensional conformal radiotherapy (56.2%). The CyberKnife plans were more conformal but less homogeneous than the 3-dimensional conformal radiotherapy plans. Approximately 50% shorter

  4. Use of High Resolution LiDAR imagery for landslide identification and hazard assessment, State Highway 6, Haast Pass, New Zealand

    NASA Astrophysics Data System (ADS)

    Walsh, Andrew; Zimmer, Valerie; Bell, David

    2015-04-01

    This study has assessed landslide hazards associated with steep and densely vegetated bedrock slopes adjacent to State Highway 6 through the Southern Alps of New Zealand. The Haast Pass serves as one of only three routes across the Southern Alps, and is a lifeline to the southern West Coast of the South Island with a 1,000km detour required through the nearest alternative pass. Over the last 50 years the highway has been subjected to numerous landslide events that have resulted in lengthy road closures, and the death of two tourists in September 2013. To date no study has been undertaken to identify and evaluate the landslide hazards for the entire Haast Pass, with previous work focusing on post-failure monitoring or investigation of individual landslides. This study identified the distribution and extent of regolith deposits on the schist slopes, and the location and sizes of dormant and active landslides potentially impacting the highway. Until the advent of LiDAR technology it had not been possible to achieve such an evaluation because dense vegetation and very steep topography prevented traditional methods of investigation (mapping; trenching; drilling; geophysics) from being used over a large part of the area. LiDAR technology has provided the tools with which to evaluate large areas of the slopes above the highway quickly and with great accuracy. A very high resolution LiDAR survey was undertaken with a flight line overlap of 70%, resulting in six points per square metre in the raw point cloud and a post-processing point spacing of half a metre. The point cloud was transformed into a digital terrain model, and the surface interpreted using texture and morphology to identify slope materials and landslides. Analysis of the LiDAR DTM revealed that the slopes above the highway consist of variable thicknesses of regolith sourced from landsliding events, as well as large areas of bare bedrock that have not been subjected to landslides and that pose minimal hazard

  5. Submarine landslides around the Canary Islands

    NASA Astrophysics Data System (ADS)

    Krastel, Sebastian; Schmincke, Hans-Ulrich; Jacobs, Colin L.; Rihm, Roland; Le Bas, Timothy P.; AlibéS, BáRbara

    2001-01-01

    The morphology and structure of the submarine flanks of the Canary Islands were mapped using the GLORIA long-range side-scan sonar system, bathymetric multibeam systems, and sediment echosounders. Twelve young (<2 Ma) giant landslides have been identified on the submarine flanks of the Canary Islands up to now. Older landslide events are long buried under a thick sediment cover due to high sedimentation rates around the Canary Islands. Most slides were found on the flanks of the youngest and most active islands of La Palma, El Hierro, and Tenerife, but young giant landslides were also identified on the flanks of the older (15-20 Ma) but still active eastern islands. Large-scale mass wasting is an important process during all periods of major magmatic activity. The long-lived volcanic constructive history of the islands of the Canary Archipelago is balanced by a correspondingly long history of destruction, resulting in a higher landslide frequency for the Canary Islands compared to the Hawaiian Islands, where giant landslides only occur late in the period of active shield growth. The lower stability of the flanks of the Canaries is probably due to the much steeper slopes of the islands, a result of the abundance of highly evolved intrusive and extrusive rocks. Another reason for the enhanced slope instability is the abundance of pyroclastic deposits on Canary Islands resulting from frequent explosive eruptions due to the elevated volatile contents in the highly alkalic magmas. Dike-induced rifting is most likely the main trigger mechanism for destabilization of the flanks. Flank collapses are a major geological hazard for the Canary Islands due to the sector collapses themselves as well as triggering of tsunamis. In at least one case, a giant lateral blast occurred when an active magmatic or hydrothermal system became unroofed during flank collapse.

  6. Landslides in Flanders (Belgium): Where science meets public policy

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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

  7. Close Range Digital Photogrammetry Applied to Topography and Landslide Measurements

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Cheng; Huang, Wei-Che

    2016-06-01

    Landslide monitoring is a crucial tool for the prevention of hazards. It is often the only solution for the survey and the early-warning of large landslides cannot be stabilized. The objective of present study is to use a low-cost image system to monitor the active landslides. We adopted the direct linear transformation (DLT) method in close range digital photogrammetry to measure terrain of landslide at the Huoyen Shan, Miaoli of central Taiwan and to compare measured results with e-GPS. The results revealed that the relative error in surface area was approximately 1.7% as comparing the photogrammetry with DLT method and e-GPS measurement. It showed that the close range digital photogrammetry with DLT method had the availability and capability to measure the landslides. The same methodology was then applied to measure the terrain before landslide and after landslide in the study area. The digital terrain model (DTM) was established and then was used to calculate the volume of the terrain before landslide and after landslide. The volume difference before and after landslides was 994.16 m3.

  8. Landslides triggered by the October 8, 2005, Pakistan earthquake and associated landslide-dammed reservoirs

    USGS Publications Warehouse

    Harp, Edwin L.; Crone, Anthony J.

    2006-01-01

    The October 8, 2005, Kashmir earthquake (M 7.6) triggered several thousand landslides, mainly rock falls and rock slides, in the epicentral area near the cities of Muzafarrabad and Balakot, Pakistan. Most of these were shallow, coalescing rock slides emanating from highly sheared and deformed limestone and dolomite of the Precambrian Muzafarrabad Formation. The largest landslide triggered by the earthquake is located approximately 32 kilometers southeast of Muzafarrabad in a tributary valley of the Jhelum River. This landslide is a debris avalanche of approximately 80 million cubic meters volume within the Miocene Murree Formation consisting of mixed sandstone, mudstone, shale, and limestone. The avalanche buried the village of Dandbeh and resulted in approximately 1,000 fatalities, according to local residents. The avalanche deposit traveled approximately 1.5 kilometers downslope and 300 meters or more up the opposite slope in the adjacent Karli stream drainage and also extended into the Tang stream drainage where the Tang stream joins the Karli drainage. The landslide mass has impounded two lakes within the blocked drainages. The lake in the Karli drainage was approximately 800 meters long and 20 meters deep as of December 19, 2005. The lake in the Tang drainage was approximately 400 meters long and 10 meters deep as of this same date. Downstream populations are at risk from possible flash flooding when these debris dams are overtopped by the reservoir water. The closest village, Hattian, is 2.8 kilometers downstream at the junction of the Jhelum River and the landslide-dammed Karli tributary. Other populations along the Jhelum River may also be at risk. Pakistan military engineers are preparing to construct a spillway within the landslide deposits to lessen the severity of the flood if the lake in the Karli stream drainage breaches the landslide dam catastrophically.

  9. Monitoring landslide kinematics by multi-temporal radar interferometry - the Corvara landslide case study

    NASA Astrophysics Data System (ADS)

    Thiebes, Benni; Cuozzo, Giovanni; Callegari, Mattia; Schlögel, Romy; Mulas, Marco; Corsini, Alessandro; Mair, Volkmar

    2016-04-01

    Corvara landslide in the Italian Dolomites is slow-moving landslide on which extensive research activities have been carried out since the 1990ies, including sub-surface techniques (e.g. drillings, piezometers and inclinometers), surface methods (e.g. geomorphological mapping and GPS measurements), and remote sensing techniques (e.g. multi-temporal radar interferometry (MTI), and recently amplitude-based offset-tracking and UAV-based photogrammetry). The currently active volume of Corvara landslide has been estimated to be approximately 25 million m³ with shear surfaces at depths of 40 m. Displacement velocities greatly vary spatially and temporally, with only a few cm per year in the accumulation zone, and more than 20 m per year in the highly active source zone. Autumn rainfall and spring snow melt, as well as accumulation of snow during winter have been identified as the major displacement triggering and accelerating events. The ongoing landslide movements pose a threat to the municipality of Corvara, the national road 244, extensive ski resort infrastructure and a golf course. Over the last years, the focus for monitoring the Corvara landslide was put on MTI using 16 artificial corner reflectors and on permanent and periodic differential GPS measurements. This aimed for (1) assessing the ongoing displacements of an active and complex landslide, and (2) analysing the benefits and limitations of MTI for landslide monitoring from the perspective of geomorphologists but also for administrative end-user such as civil protection and Geological surveys. Here, we present the latest results of these analyses, and report on the potential of MTI and related investigations, as well as future fields of research.

  10. Analysis of Submarine Landslides and Canyons along the U.S. Atlantic Margin Using Extended Continental Shelf Mapping Data

    NASA Astrophysics Data System (ADS)

    Chaytor, J. D.; Brothers, D. S.; Ten Brink, U. S.; Hoy, S. K.; Baxter, C.; Andrews, B.

    2013-12-01

    U.S. Geological Survey (USGS) studies of the U.S. Atlantic continental slope and rise aim to understand the: 1) the role of submarine landslides in tsunami generation, and 2) the linkages between margin morphology and sedimentary processes, particularly in and around submarine canyon systems. Data from U.S. Extended Continental Shelf (ECS) and numerous subsequent mapping surveys have facilitated the identification and characterization of submarine landslides and related features in fine detail over an unprecedented spatial extent. Ongoing analysis of USGS collected piston cores, sub-bottom and multichannel seismic (MCS) reflection profiles, and an extensive suite of legacy MCS data from two landslides, the Southern New England landslide zone and the Currituck Landslide, suggest that the most recent major landslide events are pre-Holocene, but that failures were complex and most likely multi-phase, at times resulting in extensive overlapping debris deposits. Piston core records plus visual observations of the seafloor from recent TowCam deployments and NOAA Ship Okeanos Explorer ROV dives reveal ongoing development of colluvial wedge-style debris aprons at the base of scarps within these landslides, showing that these regions continue to evolve long after the initial failure events. Multibeam bathymetry data and MCS profiles along the upper slope reveal evidence for vertical fluid migration and possible seabed gas expulsion. These observations underscore the need to reevaluate the sources of pore fluid overpressure in slope sediments and their role in landslide generation. ECS and more recent multibeam mapping have provided the opportunity to investigate the full extent of submarine canyon morphology and evolution from Cape Hatteras up to the US-Canadian EEZ, which has led to better understanding of the important role of antecedent margin physiography on their development. Six submarine canyon systems along the margin (Veatch, Hydrographer, Hudson, Wilmington

  11. Assessing the spatial variability of weights of landslide causal factors in different regions from Romania, using logistic regression

    NASA Astrophysics Data System (ADS)

    Margarint, M. C.; Grozavu, A.; Patriche, C. V.

    2012-04-01

    Landslides represent a significant natural hazard in hilly areas of Romania which cause important damages. The scientific interest for landslide susceptibility mapping is quite recent and standardized through legislation. However, there is need for improving the methodology, in order for the susceptibility maps to constitute a sound basis for territorial planning. The logistic regression is one of the main statistical methods used for assessing terrain susceptibility for landsliding. There are different degrees of weighting the landslide causal factors mentioned in the scientific literature, but with large variations. This study aims to identify the range of variation of landslide causal factors for different regions in Romania. The following factors were taken into consideration: slope angle, terrain altitude, terrain curvature (mean, plan and profile), soil type, lithologic class, land use, distance from drainage network and roads, mean annual precipitations. Four square perimeters of 15x15 km were chosen from representative regions in terms of spatial extent of landslides: two situated in the central-northern part of the Moldavian Plateau, one in the Transylvania Depression and one in the Moldavian Subcarpathians. The logistic regression was applied separately for the four sectors. In order to monitor the differences in the final results, numerous attempts have been made, starting from landslides polygons acquired from both the topographic maps at scale 1:25.000 (1984-1985 edition) and the ortophotoimages (2005-2006). The other elements were acquired from cartographic materials at appropriate scales, according the international methodology. The data integration was accomplished in the georeferenced environment provided by TNTMips 6.9 ArcGIS 9.3 and SAGA 2.0.8 software packages, while the statistical analysis was performed using Excel 2003 and XLSTAT 2010 trial version. Maps for all landslide causal factors were achieved for each perimeter. The logistic

  12. Flow-type landslides magnitude evaluation: the case study of the Campania Region (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Santo, Antonio; De Falco, Melania; Di Crescenzo, Giuseppe

    2015-04-01

    In the last years studies concerning the triggering and the run-out susceptibility for different kind of landslides have become more and more precise. In the most of the cases the methodological approach involve the production of detailed thematic maps (at least 1:5000 scale) which represent a very useful tool for territorial planning, especially in urbanized areas. More recently these researches were accompanied by the growth of other studies dealing with landslide magnitude evaluation (especially in terms of volume and velocity estimate). In this paper the results of a flow-type landslides magnitude evaluation are presented. The study area is located in Southern Italy and is very wide (1,500 square kilometres) including all the Campania region. In this context flow type landslides represent the most frequent instabilities as shown by the large number of victims and the huge economic damage caused in the last few centuries. These shallow landslides involve thin cohesionless, unsaturated pyroclastic soils found over steep slopes around Somma-Vesuvio and Phlegrean district, affecting a wide area where over 100 towns are located. Since the potential volume of flow-type landslides is a measure of event magnitude we propose to estimate the potential volume at the scale of slope or basin for about 90 municipalities affecting 850 hierarchized drainage basins and 900 regular slopes. An empirical approach recently proposed in literature (De Falco et al., 2012), allows to estimate the volume of the pyroclastic cover that can be displaced along the slope. The method derives from the interpretation of numerous geological and geomorphological data gathered from a vast amount of case histories on landslides in volcanic and carbonatic contexts and it is based on determining the thickness of the pyroclastic cover and the width of the detachment and erosion-transport zone. Thickness can be evaluated with a good degree of approximation since, in these landslides, the failure

  13. Evaluation of shallow landslide-triggering scenarios through a physically based approach: an example of application in the southern Messina area (northeastern Sicily, Italy)

    NASA Astrophysics Data System (ADS)

    Schilirò, L.; Esposito, C.; Scarascia Mugnozza, G.

    2015-09-01

    Rainfall-induced shallow landslides are a widespread phenomenon that frequently causes substantial damage to property, as well as numerous casualties. In recent~years a wide range of physically based models have been developed to analyze the triggering process of these events. Specifically, in this paper we propose an approach for the evaluation of different shallow landslide-triggering scenarios by means of the TRIGRS (transient rainfall infiltration and grid-based slope stability) numerical model. For the validation of the model, a back analysis of the landslide event that occurred in the study area (located SW of Messina, northeastern Sicily, Italy) on 1 October 2009 was performed, by using different methods and techniques for the definition of the input parameters. After evaluating the reliability of the model through comparison with the 2009 landslide inventory, different triggering scenarios were defined using rainfall values derived from the rainfall probability curves, reconstructed on the basis of daily and hourly historical rainfall data. The results emphasize how these phenomena are likely to occur in the area, given that even short-duration (1-3 h) rainfall events with a relatively low return period (e.g., 10-20~years) can trigger numerous slope failures. Furthermore, for the same rainfall amount, the daily simulations underestimate the instability conditions. The high susceptibility of this area to shallow landslides is testified by the high number of landslide/flood events that have occurred in the past and are summarized in this paper by means of archival research. Considering the main features of the proposed approach, the authors suggest that this methodology could be applied to different areas, even for the development of landslide early warning systems.

  14. 3-dimensional root phenotyping with a novel imaging and software platform

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel imaging and software platform was developed for the high-throughput phenotyping of 3-dimensional root traits during seedling development. To demonstrate the platform’s capacity, plants of two rice (Oryza sativa) genotypes, Azucena and IR64, were grown in a transparent gellan gum system and ...

  15. 3-DIMENSIONAL MEASURED AND SIMULATED FLOW FOR SCOUR NEAR SPUR DIKES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To improve understanding of the flow and scour processes associated with spur dikes more fully, 3-dimensional flow velocities were measured using an acoustic Doppler velocimeter at a closely spaced grid over a fixed flat bed with a submerged spur dike. Some 2592 three-dimensional velocities around a...

  16. 3-dimensional orthodontics visualization system with dental study models and orthopantomograms

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Ong, S. H.; Foong, K. W. C.; Dhar, T.

    2005-04-01

    The aim of this study is to develop a system that provides 3-dimensional visualization of orthodontic treatments. Dental plaster models and corresponding orthopantomogram (dental panoramic tomogram) are first digitized and fed into the system. A semi-auto segmentation technique is applied to the plaster models to detect the dental arches, tooth interstices and gum margins, which are used to extract individual crown models. 3-dimensional representation of roots, generated by deforming generic tooth models with orthopantomogram using radial basis functions, is attached to corresponding crowns to enable visualization of complete teeth. An optional algorithm to close the gaps between deformed roots and actual crowns by using multi-quadratic radial basis functions is also presented, which is capable of generating smooth mesh representation of complete 3-dimensional teeth. User interface is carefully designed to achieve a flexible system with as much user friendliness as possible. Manual calibration and correction is possible throughout the data processing steps to compensate occasional misbehaviors of automatic procedures. By allowing the users to move and re-arrange individual teeth (with their roots) on a full dentition, this orthodontic visualization system provides an easy and accurate way of simulation and planning of orthodontic treatment. Its capability of presenting 3-dimensional root information with only study models and orthopantomogram is especially useful for patients who do not undergo CT scanning, which is not a routine procedure in most orthodontic cases.

  17. Characterization of Students' Reasoning and Proof Abilities in 3-Dimensional Geometry

    ERIC Educational Resources Information Center

    Gutierrez, Angel; Pegg, John; Lawrie, Christine

    2004-01-01

    In this paper we report on a research aimed to identify and characterize secondary school students' reasoning and proof abilities when working with 3-dimensional geometric solids. We analyze students' answers to two problems asking them to prove certain properties of prisms. As results of this analysis, we get, on the one side, a characterization…

  18. 3-Dimensional and Interactive Istanbul University Virtual Laboratory Based on Active Learning Methods

    ERIC Educational Resources Information Center

    Ince, Elif; Kirbaslar, Fatma Gulay; Yolcu, Ergun; Aslan, Ayse Esra; Kayacan, Zeynep Cigdem; Alkan Olsson, Johanna; Akbasli, Ayse Ceylan; Aytekin, Mesut; Bauer, Thomas; Charalambis, Dimitris; Gunes, Zeliha Ozsoy; Kandemir, Ceyhan; Sari, Umit; Turkoglu, Suleyman; Yaman, Yavuz; Yolcu, Ozgu

    2014-01-01

    The purpose of this study is to develop a 3-dimensional interactive multi-user and multi-admin IUVIRLAB featuring active learning methods and techniques for university students and to introduce the Virtual Laboratory of Istanbul University and to show effects of IUVIRLAB on students' attitudes on communication skills and IUVIRLAB. Although…

  19. Geologic characteristics and movement of the Meadow Creek landslide, part of the Coal Hill landslide complex, western Kane County, Utah

    USGS Publications Warehouse

    Ashland, Francis X.; McDonald, Greg N.

    2010-01-01

    The Meadow Creek landslide, part of the Coal Hill landslide complex in western Kane County, Utah, is about 1.7 miles (2.7 km) wide and 1.3 miles (2.1 km) long and contains six smaller historical slides. The upper part of the Meadow Creek landslide is gently sloping and consists of displaced and back-rotated blocks of Cretaceous Dakota and Cedar Mountain Formations that form northeast- to locally east-trending ridges that are separated by sediment-filled half-grabens. The lower part of the landslide is gently to moderately sloping, locally incised, and consists of heterogeneous debris that overrides the Jurassic Carmel Formation near Meadow Creek. Monitoring using a survey-grade Global Positioning System (GPS) instrument detected movement of the southern part of the Meadow Creek landslide between October 2005 and October 2008, including movement of two of the historical slides-landslides 1 and 2. The most movement during the measurement period occurred within the limits of persistently moving landslide 1 and ranged from about 24 to 64 inches (61-163 cm). Movement of the abutting southern part of the Meadow Creek landslide ranged from approximately 6 to 10 inches (15-25 cm). State Route 9 crosses over approximately a mile (1.6 km) of the southern part of the Meadow Creek landslide, including landslide 1. The highway and its predecessor (State Route 15) have been periodically displaced and damaged by persistent movement of landslide 1. Most of the landslide characteristics, particularly its size, probable depth, and the inferred weak strength and low permeability of clay-rich gouge derived from the Dakota and Cedar Mountain Formations, are adverse to and pose significant challenges to landslide stabilization. Secondary hazards include piping-induced sinkholes along scarps and ground cracks, and debris flows and rock falls from the main-scarp escarpment.

  20. Root Cohesion Controls on Shallow Landslide Size, Shape and Location

    NASA Astrophysics Data System (ADS)

    Douglas, M.; Bellugi, D. G.; Perron, J.; Coe, J. A.; Schmidt, K. M.

    2013-12-01

    Many environmental factors, including ground cover, local hydrology, and recent weather events interact to cause shallow landslides and determine landslide characteristics. Vegetation is of particular interest, because changes in vegetation density, age, and composition are expected consequences of human land use and climate change. These changes alter effective cohesion due to root reinforcement, which is known to impact landslide abundance, but the effects of root cohesion on landslide size, shape and location have not been quantified. The Elliott State Forest, a 376 km2 managed forest in Douglas County, Oregon, provides an ideal venue to study these effects. There, a single storm in November 1996 triggered 154 shallow landslides, which were subsequently mapped using aerial images onto laser altimetry data, in an area with a range of vegetation ages but relatively uniform soil properties, topography, and lithology. We used aerial imagery to categorize areas with different land use histories into 3 vegetation classes, ranging from clear-cuts to forest with mature trees over 100 years old. Each mapped landslide was then assigned to a class, and its size, shape and location was recorded. Our results show that, in addition to the expected decrease in landslide abundance in more-vegetated areas (which could be influenced by a bias against detecting landslides under trees), landslides in those areas were also larger and more elongated in the down-slope direction. Although landslides in all three classes generally occurred at locations with similar drainage area and slope, we observed that slides with a larger ratio of drainage area to slope were slightly more abundant in areas with lower vegetation cover. To investigate the causes of these variations, we used a new shallow landslide model calibrated for the Oregon Coast Range to predict the size, shape and location of landslides triggered by the 1996 storm under a range of root cohesion values in a subset of the study

  1. The role of the spatial scale and data accuracy on deep-seated gravitational slope deformation modeling: The Ronco landslide, Italy

    NASA Astrophysics Data System (ADS)

    Longoni, Laura; Papini, Monica; Brambilla, Davide; Arosio, Diego; Zanzi, Luigi

    2016-01-01

    In recent decades numerical models have been developed and extensively used for landslide hazard and risk assessment. The reliability of the outcomes of these numerical simulations must be evaluated carefully as it mainly depends on the soundness of the physical model of the landslide that in turn often requires the integration of several surface and subsurface surveys in order to achieve a satisfactory spatial resolution. Merging diverse sources of data may be particularly complex for large landslides, because of intrinsic heterogeneity and possible great data uncertainty. In this paper, we assess the spatial scale and data accuracy required for effective numerical landslide modeling. We focus on two particular aspects: the model extent and the accuracy of input datasets. The Ronco landslide, a deep-seated gravitational slope deformation (DSGSD) located in the North of Italy, was used as a test-bed. Geological, geomorphological and geophysical data were combined and, as a result, eight models with different spatial scales and data accuracies were obtained. The models were used to run a back analysis of an event in 2002, during which part of the slope moved after intense rainfalls. The results point to the key role of a proper geomorphological zonation to properly set the model extent. The accuracy level of the input datasets should also be tuned. We suggest applying the approach presented here to other DSGSDs with different geological and geomorphological settings to test the reliability of our findings.

  2. Open Source Image-Processing Tools for Low-Cost Uav-Based Landslide Investigations

    NASA Astrophysics Data System (ADS)

    Niethammer, U.; Rothmund, S.; Schwaderer, U.; Zeman, J.; Joswig, M.

    2011-09-01

    In recent years, the application of unmanned aerial vehicles (UAVs) has become more common and the availability of lightweight digital cameras has enabled UAV-systems to represent affordable and practical remote sensing platforms, allowing flexible and high- resolution remote sensing investigations. In the course of numerous UAV-based remote sensing campaigns significant numbers of airborne photographs of two different landslides have been acquired. These images were used for ortho-mosaic and digital terrain model (DTM) generation, thus allowing for high-resolution landslide monitoring. Several new open source image- and DTM- processing tools are now providing a complete remote sensing working cycle with the use of no commercial hard- or software.

  3. A block-based landslide model using smooth surface reconstructions

    NASA Astrophysics Data System (ADS)

    Elsen, Katharina; Tinti, Stefano

    2014-05-01

    The present work is combining the block-based landslide-model developed by Tinti and Bertolucci (2000) with different smooth surface reconstruction methods. This enables us to directly solve the underlying ODE-system, that is describing the blocks motion, numerically. The numerical model is based on the idea that the sliding mass can be discretized by a certain number of quadrilateral blocks of finite volume, where the movement of the single blocks is described using a Lagrangian approach. Within this approach, the underlying equations of motion require for each time-step the computation of the acceleration of each of the blocks from their position on the sliding surface, where information on its curvature is needed in order to compute the centripetal component. To come up to this, different methods were used to interpolate smooth, two times differentiable, surface reconstructions from a given number of points that are describing the real sliding surface. The numerical solution of the model in time is obtained using higher-order explicit and implicit time-integration methods The results of the simulations are evaluated especially with respect to the arrival times and final velocities of the sliding mass and therefore a possible tsunamigenic impact.

  4. Pitfalls in statistical landslide susceptibility modelling

    NASA Astrophysics Data System (ADS)

    Schröder, Boris; Vorpahl, Peter; Märker, Michael; Elsenbeer, Helmut

    2010-05-01

    The use of statistical methods is a well-established approach to predict landslide occurrence probabilities and to assess landslide susceptibility. This is achieved by applying statistical methods relating historical landslide inventories to topographic indices as predictor variables. In our contribution, we compare several new and powerful methods developed in machine learning and well-established in landscape ecology and macroecology for predicting the distribution of shallow landslides in tropical mountain rainforests in southern Ecuador (among others: boosted regression trees, multivariate adaptive regression splines, maximum entropy). Although these methods are powerful, we think it is necessary to follow a basic set of guidelines to avoid some pitfalls regarding data sampling, predictor selection, and model quality assessment, especially if a comparison of different models is contemplated. We therefore suggest to apply a novel toolbox to evaluate approaches to the statistical modelling of landslide susceptibility. Additionally, we propose some methods to open the "black box" as an inherent part of machine learning methods in order to achieve further explanatory insights into preparatory factors that control landslides. Sampling of training data should be guided by hypotheses regarding processes that lead to slope failure taking into account their respective spatial scales. This approach leads to the selection of a set of candidate predictor variables considered on adequate spatial scales. This set should be checked for multicollinearity in order to facilitate model response curve interpretation. Model quality assesses how well a model is able to reproduce independent observations of its response variable. This includes criteria to evaluate different aspects of model performance, i.e. model discrimination, model calibration, and model refinement. In order to assess a possible violation of the assumption of independency in the training samples or a possible

  5. Landslide dynamics from seismology: new results

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    We have recently shown how large landslides can be detected, located, and their dynamics measured in near-real-time through inversion of long-period surface waves. Here I will talk about our discovery, over several years, of multi-km-scale landslides in remote regions across the world, several of which remain unreported, and how we have developed insights into landslide physics using a large inventory of such observations. Slope failures accelerating masses exceeding 10 megatons at 1-3m/s^2 generate forces large enough to trigger teleseismic waves detectable at broadband stations located 100s of kms distant. Inversion of such signals using a single-force model locates the epicenter to around +/-20km, and generates an approximate time series of the forces exerted by the evolving mass motion at that fixed point. This 3D vector sequence indicates the direction and magnitude of accelerations and thus momentum vector changes of the bulk landslide mass. Assuming constancy of this unknown mass during the main phase of motion allows us to infer a mass-scaled trajectory of motion of the mass center in 3D. Calibration against an observed runout distance leads to an estimate of then bulk mass. Conversely, use of an otherwise-estimated landslide mass (e.g., from differential topo mapping) leads to a calibration of the runout path without the need to observe it directly. In either case, comparison can be made against field and remote-sensing observations to check the validity of the method. Here we present multiple such tests against landslides discovered by our group in Alaska, Tibet, the Andes, and more. I will summarize analysis of the dynamical properties of these slope failures and discuss their implications. Simple scaling is seen among a host of dynamical properties, including peak force, mass, momentum, peak kinetic energy, etc. Roughly 5-15 events of this magnitude are seen globally each year. The majority strike in the periglacial environments of Alaska and Himalaya

  6. Earthquake-triggered Tsaoling landslide mechanics and dynamic process revealed by discrete element method

    NASA Astrophysics Data System (ADS)

    Chang, K.-J.; Chen, R.-F.; Chan, Y.-C.; Kuo, C.-Y.; Weng, C.-H.

    2012-04-01

    The high-speed large-scaled Tsaoling rock-and-soil avalanche is the largest landslides triggered by the Chi-Chi earthquake (Taiwan, 1999). In order to characterize the landslide mechanics and sliding behavior, this study integrates the geological and morphological features, strong motion seismostation record during block sliding on the sliding surface, and numerical simulation. The morphological analysis was performed by interpreting aerial photos taken before and at several times after the Chi-Chi earthquake. The topography of the landslide was studied by studying several 2m resolution digital elevation models (DEMs) generated from the aerial photos taken at different times. The comparison between the topographies before and after the slide allows precise calculation of the initial volume of rock and soil mobilized in the landslide, as well as the geometry and thickness of the landslide deposit. Field observations at different scales were also carried along the sliding surface and the landslide deposit and gave new insights into the mechanical behavior of the landslide, and the subsequent geomorphologic evolution of the landslide site. The major sliding surface is situated between two massive sandstones by a metric friable fine layer composing of fine layered shale, silty mudstone and interlayered beds, and is characterizing by a smooth, gentile and planar surface. The major slid mass situated on the upper slope, is an isolated hill and been daylighted. The estimated volume of the initial rocke avalanche is about 125.5 Mm3 and 138 Mm3 for the depleted and accumulation zones, respectively, indicating an increase in volume due to fragmentation. The average thickness was about 150 - 170m, up to 195 m thick of the slid mass. Whereas about 4/5 of the slid mass transport across the river and deposit around the Taochiashan hill. The hill, composed of rock debris generated by the previous events, is about 140 m higher than the Chinshui riverbed before the earthquake. The

  7. Uncertainty on shallow landslide hazard assessment: from field data to hazard mapping

    NASA Astrophysics Data System (ADS)

    Trefolini, Emanuele; Tolo, Silvia; Patelli, Eduardo; Broggi, Matteo; Disperati, Leonardo; Le Tuan, Hai

    2015-04-01

    Shallow landsliding that involve Hillslope Deposits (HD), the surficial soil that cover the bedrock, is an important process of erosion, transport and deposition of sediment along hillslopes. Despite Shallow landslides generally mobilize relatively small volume of material, they represent the most hazardous factor in mountain regions due to their high velocity and the common absence of warning signs. Moreover, increasing urbanization and likely climate change make shallow landslides a source of widespread risk, therefore the interest of scientific community about this process grown in the last three decades. One of the main aims of research projects involved on this topic, is to perform robust shallow landslides hazard assessment for wide areas (regional assessment), in order to support sustainable spatial planning. Currently, three main methodologies may be implemented to assess regional shallow landslides hazard: expert evaluation, probabilistic (or data mining) methods and physical models based methods. The aim of this work is evaluate the uncertainty of shallow landslides hazard assessment based on physical models taking into account spatial variables such as: geotechnical and hydrogeologic parameters as well as hillslope morphometry. To achieve this goal a wide dataset of geotechnical properties (shear strength, permeability, depth and unit weight) of HD was gathered by integrating field survey, in situ and laboratory tests. This spatial database was collected from a study area of about 350 km2 including different bedrock lithotypes and geomorphological features. The uncertainty associated to each step of the hazard assessment process (e.g. field data collection, regionalization of site specific information and numerical modelling of hillslope stability) was carefully characterized. The most appropriate probability density function (PDF) was chosen for each numerical variable and we assessed the uncertainty propagation on HD strength parameters obtained by

  8. Landslide detectability with coarse resolution imagery: a Sentinel-2 emulation study to access spectral landslide discrimination.

    NASA Astrophysics Data System (ADS)

    Mota, Bernardo; Mondini, Alessandro; Malamud, Bruce D.; Mihir, Monika; Drake, Nick

    2014-05-01

    In this paper we explore landslide detectability using a simulation of course resolution (10 m) remote sensing imagery. During the last decade the increasing availability of Very High Resolution (VHR) imagery has significantly improved accuracies obtained by change detection classification algorithms. Still, one of the disadvantages is a spatial-temporal compromise, in that the VHR imagery is generally not taken frequently over the same region. The planed optical sensor aboard the two Sentinel-2 satellites will potentially overcome this limitation, as the sensor will be able to supply coarse resolution images (10 m) with a revisiting period of 5 days at the equator. This will potentially allow for quick assessments after groups of landslides are triggered (e.g., by an earthquake or heavy rainfall) anywhere in the world, soon after the landslides occurs. The scope of this study is to analyse the potential limitations supplied by this imagery for landslide detection. For the study, pre and post Sentinel-2 images were emulated by downgrading two Quickbird satellite images, taken on 2 September 2006 and on 8 October 2009, over the Messina province in Sicily, Italy, where on 1 October 2009 a rainfall storm triggered landslides, soil erosion and inundation. Spectral information, based on change detection indexes (NDVI difference, principal component analysis and spectral angle), were extracted for the stable and unstable areas according to an independent landslide inventory. The inventory was derived by aerial photo interpretation prepared at 1:10,000 scale covering three catchments with a total area of 15 km2 and characterized by soil slips and debris flows affecting 7.9% of the area. Stable and unstable spectral discrimination was determined by analysing their separability, and imposing different areal thresholds between stable and unstable areas, for both mass source and debris flow landslide types. Preliminary results show good agreement between the original and

  9. Tsunami Squares Approach to Landslide-Generated Waves: Application to Gongjiafang Landslide, Three Gorges Reservoir, China

    NASA Astrophysics Data System (ADS)

    Xiao, Lili; Ward, Steven N.; Wang, Jiajia

    2015-12-01

    We have developed a new method, named "Tsunami Squares", for modeling of landslides and landslide-generated waves. The approach has the advantages of the previous "Tsunami Ball" method, for example, separate, special treatment for dry and wet cells is not needed, but obviates the use of millions of individual particles. Simulations now can be expanded to spatial scales not previously possible. The new method accelerates and transports "squares" of material that are fractured into new squares in such a way as to conserve volume and linear momentum. The simulation first generates landslide motion as constrained by direct observation. It then computes induced water waves, given assumptions about energy and momentum transfer. We demonstrated and validated the Tsunami Squares method by modeling the 2008 Three Gorges Reservoir Gongjiafang landslide and river tsunami. The landslide's progressive failure, the wave generated, and its subsequent propagation and run-up are well reproduced. On a laptop computer Tsunami Square simulations flexibly handle a wide variety of waves and flows, and are excellent techniques for risk estimation.

  10. A kinematic model of the Suao landslide calibrated to the morphology of the landslide deposit

    NASA Astrophysics Data System (ADS)

    Wei, L. W.; Lo, C. M.; Lee, C. F.; Chou, H. T.; Lin, M. L.

    2012-04-01

    This study presents results of a case study on the Suao catastrophic landslide, including its kinematic process and the deposition geometry. A 3D discrete element method (program), PFC3D was used to model the kinematic process that led to the landslide and destruction of 115.9k Suhua highway. The landslide advanced from debris slide to debris avalanche during the kinematic process. Assuming a friction coefficient of each particle of 0.05, the predicted maximum velocity was about 50 m/s, the material in the source area collapsed and moved out in about 30 seconds, part of particles deposit downstream, and the whole process finished in the period of about 132.5 seconds. The simulation mimics the process of landslide and alluvial fan in very detail, and the final form is close to real situation. However, it should be reminded that the entrainment from banks and channel bed is neglected by employing PFC3D. Key word: Suao catastrophic landslide, kinematic process, deposition geometry, discrete element method

  11. Modelling past landslide-induced tsunami in Lake Geneva to evaluate the present threat

    NASA Astrophysics Data System (ADS)

    Franz, Martin; Jaboyedoff, Michel; Podladchikov, Yury

    2014-05-01

    In the south-eastern part of Lake Geneva, in the community of Meillerie, France, is located a forested depression, which indicates that a landslide occurred at this place in a distant past. It is a partially submerged slide composed of Trias to Jurassic carbonates. As its volume is greater than 10 mio m3, we assume that a potential brusque failure would have generated an impulse wave able to spread across the lake and reach the location of contemporary cities. Since this type of events is still likely to occur nowadays, this study aims to characterise the tsunami triggered by the past landslide event in order to know the potential wave height in populated places around the lake for events of similar magnitude. The volume of the displaced mass is estimated using the inverse Sloping Local Base Level (SLBL) by subtracting the pre-failure topography (built with the SLBL) to the actual one. In order to model landslide-triggered tsunami, it is necessary to be able to simulate the generation, the propagation of the wave in the lake and on the shores. This task is performed using a two-dimensional numerical model based on the shallow water equations. The Lax-Friedrichs scheme is used for the numerical stabilisation. The preliminary results indicate that the wave propagated across the lake up to distant places. As the shores are today extensively urbanised, in a similar case, they would be subject to catastrophic consequences. Thus, sensitivity tests are conducted for variation of the size and the velocities of the landslide in the model in order to give a distribution of the associated risks.

  12. Submarine Landslides: What we Know and Where we are Going!

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Submarine landslides and other gravity-induced movements can disrupt ver