Science.gov

Sample records for 3-dimensional numerical landslide

  1. 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.

  2. 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.

  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. 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

  5. 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)

  6. 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.

  7. Numerical study of the directed polymer in a 1 + 3 dimensional random medium

    NASA Astrophysics Data System (ADS)

    Monthus, C.; Garel, T.

    2006-09-01

    The directed polymer in a 1+3 dimensional random medium is known to present a disorder-induced phase transition. For a polymer of length L, the high temperature phase is characterized by a diffusive behavior for the end-point displacement R2 ˜L and by free-energy fluctuations of order ΔF(L) ˜O(1). The low-temperature phase is characterized by an anomalous wandering exponent R2/L ˜Lω and by free-energy fluctuations of order ΔF(L) ˜Lω where ω˜0.18. In this paper, we first study the scaling behavior of various properties to localize the critical temperature Tc. Our results concerning R2/L and ΔF(L) point towards 0.76 < Tc ≤T2=0.79, so our conclusion is that Tc is equal or very close to the upper bound T2 derived by Derrida and coworkers (T2 corresponds to the temperature above which the ratio bar{Z_L^2}/(bar{Z_L})^2 remains finite as L ↦ ∞). We then present histograms for the free-energy, energy and entropy over disorder samples. For T ≫Tc, the free-energy distribution is found to be Gaussian. For T ≪Tc, the free-energy distribution coincides with the ground state energy distribution, in agreement with the zero-temperature fixed point picture. Moreover the entropy fluctuations are of order ΔS ˜L1/2 and follow a Gaussian distribution, in agreement with the droplet predictions, where the free-energy term ΔF ˜Lω is a near cancellation of energy and entropy contributions of order L1/2.

  8. 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

  9. A numerical landscape evolution model incorporating slow, deep-seated landslides

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    In many mountainous landscapes, deep-seated landslides transport large volumes of sediment and exert a strong control on topographic development. Specifically, they tend to reduce slope angles and catchment relief, disrupt the channel network, and form topographic benches, which are often underlain by deep zones of weathered material. Remote sensing studies frequently utilize these characteristics to compile landslide inventories and assess the role landslides play in shaping topography, but quantitative process models capable of generating deep-seated landslide features are comparably sparse. Here, we present a numerical landscape evolution model that generates these deep-seated landslide-related features at the drainage basin scale (~1 km2) by coupling equations for soil creep, fluvial incision, and bedrock weathering with a novel treatment of deep-seated landslide processes. Soil creep sediment flux is proportional to the local topographic gradient, fluvial incision is proportional to stream power, and the weathering rate is assumed to decay exponentially with the depth of weathered material. In the model, deep-seated landslides transport weathered material through a combination of basal sliding at the bedrock interface and internal deformation in a manner analogous to glacial movement. As a model landscape evolves from an initial surface with meter-scale roughness, deep-seated landslides localize where fluvial incision is rapid, such as near knickpoints and in the headwaters of incipient drainages, and develop into long-lived, persistently active features. Superimposed on these features are episodes of increased landslide activity lasting for hundreds to thousands of years that often force lateral migration of fluvial channels and inhibit formation of new channels. This landslide activity leaves a legacy in the landscape of broad, bench-type topography underlain by deep pockets of weathered material that persists for millions of years. We quantify the above

  10. 3-dimensional numerical modeling of an industrial radio frequency heating system using finite elements.

    PubMed

    Chan, T V Chow Ting; Tang, J; Younce, F

    2004-01-01

    This paper presents a new, yet simple and effective approach to modeling industrial Radio Frequency heating systems, using the wave equation applied in three dimensions instead of the conventional electrostatics method. The central idea is that the tank oscillatory circuit is excited using an external source. This then excites the applicator circuit which is then used to heat or dry the processed load. Good agreement was obtained between the experimental and numerical data, namely the S11-parameter, phase, and heating patterns for different sized loads and positions.

  11. A Fast Apparent-Horizon Finder for 3-Dimensional Cartesian Grids in Numerical Relativity

    NASA Astrophysics Data System (ADS)

    Thornburg, Jonathan

    2003-10-01

    In 3 + 1 numerical simulations of dynamic black hole spacetimes, it's useful to be able to find the apparent horizon(s) (AH) in each slice of a time evolution. A number of AH finders are available, but they often take many minutes to run, so they're too slow to be practically usable at each time step. Here I present a new AH finder, AHFINDERDIRECT, which is very fast and accurate, typically taking only a few seconds to find an AH to ~ 10-5m accuracy on a GHz-class processor. I assume that an AH to be searched for is a Strahlkörper (``star-shaped region'') with respect to some local origin, and so parameterize the AH shape by r = h(angle) for some single-valued function h: S2 --> R+. The AH equation then becomes a nonlinear elliptic PDE in h on S2, whose coefficients are algebraic functions of gij, Kij, and the Cartesian-coordinate spatial derivatives of gij. I discretize S2 using 6 angular patches (one each in the neighborhood of the +/-x, +/-y, and +/-z axes) to avoid coordinate singularities, and finite difference the AH equation in the angular coordinates using 4th order finite differencing. I solve the resulting system of nonlinear algebraic equations (for h at the angular grid points) by Newton's method, using a ``symbolic differentiation'' technique to compute the Jacobian matrix. AHFINDERDIRECT is implemented as a thorn in the CACTUS computational toolkit, and will be made freely available starting in fall 2003.

  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. Numerical modeling of rainfall thresholds for shallow landsliding in the Seattle, Washington, area

    USGS Publications Warehouse

    Godt, Jonathan W.; McKenna, Jonathan P.

    2008-01-01

    The temporal forecasting of landslide hazard has typically relied on empirical relations between rainfall characteristics and landslide occurrence to identify conditions that may cause shallow landslides. Here, we describe an alternate, deterministic approach to define rainfall thresholds for landslide occurrence in the Seattle, Washington, area. This approach combines an infinite slope-stability model with a variably saturated flow model to determine the rainfall intensity and duration that leads to shallow failure of hillside colluvium. We examine the influence of variation in particle-size distribution on the unsaturated hydraulic properties of the colluvium by performing capillary-rise tests on glacial outwash sand and three experimental soils with increasing amounts of fine-grained material. Observations of pore-water response to rainfall collected as part of a program to monitor the near-surface hydrology of steep coastal bluffs along Puget Sound were used to test the numerical model results and in an inverse modeling procedure to determine the in situ hydraulic properties. Modeling results are given in terms of a destabilizing rainfall intensity and duration, and comparisons with empirical observations of landslide occurrence and triggering rainfall indicate that the modeling approach may be useful for forecasting landslide occurrence.

  15. 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.

  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. 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

  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. 3-D Numerical Investigation of the Tsaoling Landslide Induced by Chi-Chi Earthquake, Taiwan.

    NASA Astrophysics Data System (ADS)

    Tang, C.; Hu, J.

    2004-12-01

    Large landslides occurred in the mountainous area near the epicenter of the Sept. 21st, 1999, Chi-Chi earthquake in central Taiwan. These landslides were triggered by the Mw = 7.6 earthquake, which resulted in more than 2,400 human casualties and widespread damage. The 1999 Chi-Chi earthquake triggered a catastrophic Tsaloing landslide, which mobilized about 0.125 km3 of rock and soil that slid across the Chingshui River and created a 5 km long natural dam. One fifth of the landslide mass dropped into the Chingshui River, the rest jumped over the river. At least five large landslides occurred in Tsaoling area are induced by big earthquake and heavy rainfalls since 1862 to 1999. Geological investigation shows that the prevailing attitude of sedimentary formation is about N45W with a dipping angle of 12S. First we used Remark Method to calculate the stability of slope. The bottom of slope has been eroded by Chingshui stream, and the PGA (Peak Ground Acceleration) in Chi-Chi earthquake was exceeded the yield acceleration along the sliding surface. The landslide mechanism may be including flowing, rolling, bouncing and sliding. The rock on the fault plane during faulting can generate pseudotachylyte resulted from melted rock by frictional heat energy along the sliding surface. The frictional melted rocks were found out in the Chiu-Fen-Erh-Shan collapses. However, we didn¡¦t found out the frictional melted rock in Tsaoling area. If we calculated the kinetic energy which was converted to heat energy, the increase of temperature was enough to melt the rocks on sliding surface. When the rocks on the sliding surface had been melted, the friction on the sliding surface must be decrease. Therefore, the 0.125 km3 debris had sufficient kinetic energy to across Chingshui River to the other side of the river. Using 3D distinct-element modeling (PFC3d code), we try to simulate kinematic process of Tsaoling landslide. Our numerical model was compose of about 10,000 spherical

  1. 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

  2. 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

  3. 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.

  4. Numerical modeling of the Mount Meager landslide constrained by its force history derived from seismic data

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    We focus on the 6 August 2010 Mount Meager landslide that occurred in Southwest British Columbia, Canada. This 48.5 Mm3 rockslide that rapidly changed into a debris flow was recorded by over 25 broadband seismic stations. We showed that the waveform inversion of the seismic signal making it possible to calculate the time history of the force applied by the landslide to the ground is very robust and stable, even when using only data from a single station. By comparing this force with the force calculated through numerical modeling of the landslide, we are able to support the interpretation of seismic data made using a simple block model. However, our study gives different values of the friction coefficients involved and more details about the volumes and orientation of the subevents and the flow trajectory and velocity. Our sensitivity analysis shows that the characteristics of the released mass and the friction coefficients all contribute to the amplitude and the phase of the force. Despite this complexity, our study makes it possible to discriminate the best values of all these parameters. Our results suggest that comparing simulated and inverted forces helps to identify appropriate rheological laws for natural flows. We also show that except for the initial collapse, peaks in the low-frequency force related to bends and runup over topography changes are associated with high-frequency generation, possibly due to an increased agitation of the granular material involved.

  5. SLOWMOVE - A numerical model for the propagation of slow-moving landslides: a 1D approach and its application to the analysis of the Valoria landslide (Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Daehne, A.; van Asch, Th. W. J.; Corsini, A.; Spickerman, A.; Bégueria-Portuguès, S.

    2010-05-01

    Understanding the behavior of landslides often starts with a numerical simulation that accurately accounts for observed physical processes. This research proposes a method for the implementation of the dynamic SLOWMOVE model to a high-mobility, moderate velocity earth flow located in the northern Apennines. The Valoria landslide is 3.5 km long earth slide- earth flow that resumed activity in 2001. Landslide materials comprised of disaggregated Flysch, Marl and Claystones are mainly transported as earth slides in the upper slope, and as earth flows in the main track. Repeated acceleration events lasting several weeks occur seasonally since 2001 reactivation. During events it can reach velocities of about 10 m per hour with a cumulative displacement of hundreds of meters. Through this intermittent activity, more than ten million cubic meters have been transferred down-slope since 2001, changing significantly and several times the morphology of the slope. The SLOWMOVE model postulates that landslide materials can be represented as a homogeneous material with rheological properties and constant density. The approach is based on the Navier-Stokes equations. Under the assumptions that the inertia of the moving mass can be neglected, the behavior of the landslide depends solely on the balance between driving forces and resisting forces which contain a Coulomb-viscous component. Excess pore pressure due to undrained loading and lateral force form the main parameters that control the acceleration. The effects of lateral force and excess pore pressure allow a numerical simulation of landslide reactivation by coupling of two landslide bodies. A numerical scheme based on a finite difference solution (2D Eulerian space with Cartesian coordinates) was implemented in Microsoft Excel and used to compute propagation of the mass in 1D. The model allows coupling between mass movements having different geotechnical characteristic. In practice, it allows simulating the reactivation of

  6. Numerical analysis of the effect of root reinforcement on the triggering of shallow landslides

    NASA Astrophysics Data System (ADS)

    Schwarz, Massimiliano; Cohen, Denis; Giadrossich, Filippo

    2014-05-01

    Triggering mechanisms of shallow landslides in vegetated slopes are strongly influenced by roots and their distribution. The mechanical properties of rooted soils are reported in numerous studies but are yet to be widely used for slope stability calculations. Quantifying root reinforcement in slope stability calculation, is difficult due to the complexity of soil-root interactions and the lack of knowledge of spatial root distribution. Moreover, the compressibility of rooted soil contributes both to the stiffness of the body of the slope and to the foot of the slope. Thus, they plays a fundamental role in landslide activation. Next to the well-documented contribution of roots to shear and tensile strength of soils, there are no studies that discuss the effects of roots on the compressibility of soils and how this mechanical property influences the triggering and size of shallow landslides. In this study we present the results of the sensitivity analysis of the SOSlope model based on the implementation of recent field and laboratory investigation results on the effects of root reinforcement and water content on the tensile-compressive behavior of rooted soil. The model simulates the effects of the spatial and temporal variability of root reinforcement on the stability of a slope as a function of position, dimension, and tree species. Including the compressive behavior or rooted soils is particularly important to estimate how vegetation stabilizes slopes of protection forests and bioengineered slopes. Results of the model are compared to field observations and discussed in the context of future validations. This study represents an important improvement for strategies within the scope of bioengineering measures and for the management of protection forests against shallow landslides.

  7. Tsunamis Triggered by Submarine Landslides in the NE Atlantic: Evidences of Mass Failures and Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Omira, R.; Ramalho, I.; Baptista, M. A.; Miranda, J. M. A.; Batista, L.; Terrinha, P.

    2014-12-01

    Tsunamis caused by submarine mass failures constitute a widely recognized source of natural hazard. However, in the NE Atlantic the tsunami hazard posed by landslides remains poorly studied. In this study, we attempt to contribute to a better understanding of the tsunami hazard of landslides origin. We investigate the tsunami hazard posed by deepwater submarine landslide failures in the Gorringe Bank (GB) area, NE Atlantic. This investigation requires detailed marine geological data and a robust numerical model to simulate both the mass failure flow and the subsequent tsunami. The analysis of both swath-bathymetric data and the multichannel seismic profiles revealed evidences of the presence of at least three large deepwater mass failures in the GB area of possible tsunamigenic potential. It also allows defining the geomorphologic characteristics of the identified submarine landslides, which include the erosional area (dimensions, scarps) and the depositional area (sediments extent, volume). Some depositional volumes reach ~80km3. To simulate the flow of the mudslide failure and the wave induced by the seafloor motion we employ a multi-layers viscous shallow-water (VSW) model. The lower layer represents the slide assumed to be a viscous-incompressible fluid, and characterized by sediments density, and kinematic viscosity. It is bounded by the upper layer consisting of seawater assumed to be inviscid and incompressible. We solve the VSW equations in a finite-difference scheme considering a "two-way" coupling approach. The results are presented in terms of: i) evidences of submarine mass failures in the area of GB; ii) simulations of seafloor motion due to the occurrence slides failures; ii) simulations of tsunami generation induced by the submarine landslide flow; and iii) simulations of tsunami propagation and coastal impact. Results show that, using the VSW model, we are able to reliably reproduce the sediment deposit induced by slide failures. In some cases, the

  8. The 1963 Vajont landslide (Italy) simulated through a numerical 2D code

    NASA Astrophysics Data System (ADS)

    Zaniboni, Filippo; Ausilia Paparo, Maria; Elsen, Katharina; Tinti, Stefano

    2013-04-01

    On October 9th, 1963, a huge mass of about 260 million m3 collapsed along Mt. Toc flank into the artificial lake called Vajont and generated a gigantic wave that invested the town of Longarone (North-East Italy, about 100 km north of Venice), provoking about 2000 casualties. The event started a public debate on the responsibilities for the disaster, and also raised crucial issues for the scientific and engineering community, regarding reservoir flank instability and safety of the hydroelectric plant. The peculiar features of the event were immediately evident. The clay layers remained uncovered in the upper part of the detachment niche, supporting the hypothesis of a well-defined pre-existing sliding surface, that could explain the high falling velocity (around 20 m/s as a maximum) and the compactness of the deposit layers that were found to sit almost unperturbed on the bottom of the valley. The numerical study presented here contributes to the understanding of dynamics of the Vajont landslide. It is found that the accurate knowledge of the pre- and post-slide morphology provides tight constraints on the parameters of the numerical model, that are tuned to fit the observed deposit. Numerical simulations are carried out by means of the in-house built code UBO-BLOCK2. The initial sliding body is divided into a mesh of interacting volume-conserving blocks, whose motion is computed numerically. The friction coefficient at the base of the landslide is determined through a best fit search by maximizing the degree of overlapping between the calculated and observed deposits. Our best solution is also able to account for the observed slight easterly rotation of the mass, the different behaviors of the eastern and western part of the sliding surface and the retrogressive motion of the slide that after climbing up the opposite flank of the valley reverted velocity to settle down on the bottom of the valley.

  9. Numerical modelling of historical landslide-generated tsunamis in the French Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Poisson, B.; Pedreros, R.

    2010-06-01

    Two historical landslide-induced tsunamis that reached the coasts of the French Lesser Antilles are studied. First, the Martinique coast was hit by a tsunami down the western flank of Montagne Pelée at the beginning of the big eruption of May 1902. More recently, the northeastern coast of Guadeloupe was affected by a tsunami that had been generated around Montserrat by pyroclastic flows entering the sea, during the July 2003 eruption of the Soufrière Hills volcano. We use a modified version of the GEOWAVE model to compute numerical simulations of both events. Two source hypotheses are considered for each tsunami. The comparison of the simulation results with reported tsunami height data helps to discriminate between the tested source decriptions. In the Martinique case, we obtain a better fit to data when considering three successive lahars entering the sea, as a simplified single source leads to an overstimation of the tsunami wave heights at the coast. In the Montserrat case, the best model uses a unique source which volume corresponds to published data concerning the peak volume flow. These findings emphasize the importance of an accurate description of the relevant volume as well as the timing sequence of the source event in landslide-generated tsunami modelling. They also show that considering far-field effects in addition to near-field effects may significantly improve tsunami modelling.

  10. Numerical simulation of transonic propeller flow using a 3-dimensional small disturbance code employing novel helical coordinates

    NASA Technical Reports Server (NTRS)

    Snyder, Aaron

    1987-01-01

    The numerical simulation of three-dimensional transonic flow about propeller blades is discussed. The equations for the unsteady potential flow about propellers is given for an arbitrary coordinate system. From this the small disturbance form of the equation is derived for a new helical coordinate system. The new coordinate system is suited to propeller flow and allows cascade boundary conditions to be applied straightforward. A numerical scheme is employed which solves the steady flow as an asymptotic limit of unsteady flow. Solutions are presented for subsonic and transonic flow about a 5 percent thick bicircular arc blade of an eight bladed cascade. Both high and low advance ratio cases are given which include a lifting case as well as nonlifting cases. The nonlifting cases are compared to solutions from a Euler code.

  11. A simplified 3-D Navier-Stokes numerical model for landslide-tsunami: Application to the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Horrillo, J.; Wood, A.; Kim, G.-B.; Parambath, A.

    2013-12-01

    A simplified three-dimensional Navier-Stokes (3-D NS) model for two fluids, water and landslide material (mudslide) is presented and validated with standard laboratory experiments. Dubbed TSUNAMI3D (Tsunami Solution Using Navier-Stokes Algorithm with Multiple Interfaces) is applied to a 3-D full-scale landslide scenario in the Gulf of Mexico (GOM), i.e., the East-Breaks underwater landslide. The simplified 3-D NS model is conceived to be computationally efficient for tsunami calculations. The simplification is derived from the large aspect ratio of the tsunami waves (wavelength/wave-height) and the selected computational grid that has a smaller aspect ratio. This allows us to assume a horizontal fluid surface in each individual cell containing the interface (air-water, air-mudslide, and water-mudslide). The tracking of fluid interfaces is based on the Volume of Fluid method and the surfaces are obtained by integrating the fluxes of each individual fluid cell along the water column. In the momentum equation, the pressure term is split into two components, hydrostatic and nonhydrostatic. The internal friction is solved in a simplified manner by adjusting the viscosity coefficient. Despite the simplification to get an efficient solution, the numerical results agree fairly well with standard landslide laboratory experiments required by the National Tsunami Hazard Mitigation Program for tsunami model validation. The numerical effect caused by using a sharp versus a diffusive water-mudslide interface for a full-scale landslide-tsunami scenario is also investigated. Observations from this experiment indicated that choosing a sharp or diffusive interface seems to have no remarkable effect at early stages of the tsunami wave propagation. Last, a large scale 3-D numerical simulation is carried out for the ancient GOM's East-Breaks landslide by using the simplified model to calculate the early stages of the tsunami wave propagation.

  12. On the instability of a 3-dimensional attachment line boundary layer: Weakly nonlinear theory and a numerical approach

    NASA Technical Reports Server (NTRS)

    Hall, P.; Malik, M. R.

    1984-01-01

    The instability of a three dimensional attachment line boundary layer is considered in the nonlinear regime. Using weakly nonlinear theory, it is found that, apart from a small interval near the (linear) critical Reynolds number, finite amplitude solutions bifurcate subcritically from the upper branch of the neutral curve. The time dependent Navier-Stokes equations for the attachment line flow have been solved using a Fourier-Chebyshev spectral method and the subcritical instability is found at wavenumbers that correspond to the upper branch. Both the theory and the numerical calculations show the existence of supercritical finite amplitude (equilibrium) states near the lower branch which explains why the observed flow exhibits a preference for the lower branch modes. The effect of blowing and suction on nonlinear stability of the attachment line boundary layer is also investigated.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  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. 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)

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. Sector collapse at Kick 'em Jenny submarine volcano (Lesser Antilles): numerical simulation and landslide behaviour

    NASA Astrophysics Data System (ADS)

    Dondin, Frédéric; Lebrun, Jean-Frédéric; Kelfoun, Karim; Fournier, Nicolas; Randrianasolo, Auran

    2012-03-01

    Kick 'em Jenny volcano is the only known active submarine volcano in the Lesser Antilles. It lies within a horseshoe-shaped structure open to the west northwest, toward the deep Grenada Basin. A detailed bathymetric survey of the basin slope at Kick 'em Jenny and resulting high-resolution digital elevation model allowed the identification of a major submarine landslide deposit. This deposit is thought to result from a single sector collapse event at Kick 'em Jenny and to be linked to the formation of the horseshoe-shaped structure. We estimated the volume and the leading-edge runout of the landslide to be ca. 4.4 km3 and 14 km, respectively. We modelled a sector collapse event of a proto Kick 'em Jenny volcano using VolcFlow, a finite difference code based on depth-integrated mass and momentum equations. Our models show that the landslide can be simulated by either a Coulomb-type rheology with low basal friction angles (5.5°-6.5°) and a significant internal friction angle (above 17.5°) or, with better results, by a Bingham rheology with low Bingham kinematic viscosity (0 < ν B < 30 m2/s) and high shear strength (130 < γ ≤ 180 m2/s2). The models and the short runout distance suggest that the landslide travelled as a stiff cohesive flow affected by minimal granular disaggregation and slumping on a non-lubricated surface. The main submarine landslide deposit can therefore be considered as a submarine mass slide deposit that behaved like a slump.

  7. Landslide Hazards

    USGS Publications Warehouse

    ,

    2000-01-01

    Landslide hazards occur in many places around What Can You Do If You Live Near Steep Hills? the world and include fast-moving debris flows, slow-moving landslides, and a variety of flows and slides initiating from volcanoes. Each year, these hazards cost billions of dollars and cause numerous fatalities and injuries. Awareness and education about these hazards is a first step toward reducing damaging effects. The U.S. Geological Survey conducts research and distributes information about geologic hazards. This Fact Sheet is published in English and Spanish and can be reproduced in any form for further distribution. 

  8. 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

  9. Numerical simulation of a flow-like landslide using the particle finite element method

    NASA Astrophysics Data System (ADS)

    Zhang, Xue; Krabbenhoft, Kristian; Sheng, Daichao; Li, Weichao

    2015-01-01

    In this paper, an actual landslide process that occurred in Southern China is simulated by a continuum approach, the particle finite element method (PFEM). The PFEM attempts to solve the boundary-value problems in the framework of solid mechanics, satisfying the governing equations including momentum conservation, displacement-strain relation, constitutive relation as well as the frictional contact between the sliding mass and the slip surface. To warrant the convergence behaviour of solutions, the problem is formulated as a mathematical programming problem, while the particle finite element procedure is employed to tackle the issues of mesh distortion and free-surface evolution. The whole procedure of the landslide, from initiation, sliding to deposition, is successfully reproduced by the continuum approach. It is shown that the density of the mass has little influence on the sliding process in the current landslide, whereas both the geometry and the roughness of the slip surface play important roles. Comparative studies are also conducted where a satisfactory agreement is obtained.

  10. 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

  11. 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

  12. 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

  13. Water related triggering mechanisms of shallow landslides: Numerical modelling of hydraulic flows in slopes verified with field experiments

    NASA Astrophysics Data System (ADS)

    Broennimann, C.; Tacher, L.

    2009-04-01

    To assess hill slope stability and landslide triggering mechanisms, it is essential to understand the hydrogeological regime in slopes. In this work finite element models are elaborated and field experiments are carried out to study particularly shallow landslides with thickness of a few meters. The basis hypothesis of the presented research assumes that even for shallow landslides the hydrogeological role of the substratum, mostly bedrock, is determinant for the slopes behaviour, either it is draining or feeding the overlaying unstable mass. The investigated area of about 1 square kilometre is situated next to the villages Buchberg and Rüdlingen (canton Schaffhausen, Switzerland) at the border of the river Rhine. The lithology in this region is characterized mainly by horizontally layered sandstones intersected by marls from the upper seawater and the lower freshwater molasse, overlaid by soil and weathered bedrock of about 1 to 4 m thickness, both classified as silty sands. With a slope inclination of locally up to 40° the area is rather steep and characterized by continuous regressive erosion processes. During heavy rainfall events, such as the one from May 2002, shallow landslides occurred in the area affecting afforested soils as well as woodless areas. Geological field observations, infiltration and tracer tests show a fairly complicated hydrogeological character of the region. Along the slope, in the first few meters of depth, no groundwater table was found. However, seasonally controlled sources can be observed in-between outcropping bedrock. Within the sandstone, vertical faults in decametre scale oriented parallel to the Rhine that most likely opened during decompression due to the cutting of the river affect locally the hydrogeological regime by draining the slope. This implies a high grade of heterogeneity in the water flows in a local scale. Based on these conceptual hydrological and geological models, a numerical flow model was obtained using finite

  14. 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.

  15. 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)

  16. Calibration of the landsliding numerical model SLIPOS and prediction of the seismically induced erosion for several large earthquakes scenarios

    NASA Astrophysics Data System (ADS)

    Jeandet, Louise; Lague, Dimitri; Steer, Philippe; Davy, Philippe; Quigley, Mark

    2016-04-01

    Coseismic landsliding is an important contributor to the long-term erosion of mountain belts. But if the scaling between earthquakes magnitude and volume of sediments eroded is well known, the understanding of geomorphic consequences as divide migration or valley infilling still poorly understood. Then, the prediction of the location of landslides sources and deposits is a challenging issue. To progress in this topic, algorithms that resolves correctly the interaction between landsliding and ground shaking are needed. Peak Ground Acceleration (PGA) have been shown to control at first order the landslide density. But it can trigger landslides by two mechanisms: the direct effect of seismic acceleration on forces balance, and a transient decrease in hillslope strength parameters. The relative importance of both effects on slope stability is not well understood. We use SLIPOS, an algorithm of bedrock landsliding based on a simple stability analysis applied at local scale. The model is capable to reproduce the Area/Volume scaling and area distribution of natural landslides. We aim to include the effects of earthquakes in SLIPOS by simulating the PGA effect via a spatially variable cohesion decrease. We run the model (i) on the Mw 7.6 Chi-Chi earthquake (1999) to quantitatively test the accuracy of the predictions and (ii) on earthquakes scenarios (Mw 6.5 to 8) on the New-Zealand Alpine fault to infer the volume of landslides associated with large events. For the Chi-Chi earthquake, we predict the observed total landslides area within a factor of 2. Moreover, we show with the New-Zealand fault case that the simulation of ground acceleration by cohesion decrease lead to a realistic scaling between the volume of sediments and the earthquake magnitude.

  17. 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

  18. 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.

  19. Numerical Modeling of Earthquake-Induced Landslide Using an Improved Discontinuous Deformation Analysis Considering Dynamic Friction Degradation of Joints

    NASA Astrophysics Data System (ADS)

    Huang, Da; Song, Yixiang; Cen, Duofeng; Fu, Guoyang

    2016-12-01

    Discontinuous deformation analysis (DDA) as an efficient technique has been extensively applied in the dynamic simulation of discontinuous rock mass. In the original DDA (ODDA), the Mohr-Coulomb failure criterion is employed as the judgment principle of failure between contact blocks, and the friction coefficient is assumed to be constant in the whole calculation process. However, it has been confirmed by a host of shear tests that the dynamic friction of rock joints degrades. Therefore, the friction coefficient should be gradually reduced during the numerical simulation of an earthquake-induced rockslide. In this paper, based on the experimental results of cyclic shear tests on limestone joints, exponential regression formulas are fitted for dynamic friction degradation, which is a function of the relative velocity, the amplitude of cyclic shear displacement and the number of its cycles between blocks with an edge-to-edge contact. Then, an improved DDA (IDDA) is developed by implementing the fitting regression formulas and a modified removing technique of joint cohesion, in which the cohesion is removed once the `sliding' or `open' state between blocks appears for the first time, into the ODDA. The IDDA is first validated by comparing with the theoretical solutions of the kinematic behaviors of a sliding block on an inclined plane under dynamic loading. Then, the program is applied to model the Donghekou landslide triggered by the 2008 Wenchuan earthquake in China. The simulation results demonstrate that the dynamic friction degradation of joints has great influences on the runout and velocity of sliding mass. Moreover, the friction coefficient possesses higher impact than the cohesion of joints on the kinematic behaviors of the sliding mass.

  20. Emplacement of volcanic debris landslide deposits: new insight from distinct element numerical simulations

    NASA Astrophysics Data System (ADS)

    Thompson, N.; Bennett, M.; Petford, N.

    2008-12-01

    The emplacement processes of large-scale volcanic debris avalanche events remain poorly understood. Much of what we know about this complex process is interpreted from deposits that typically contain a suite of commonly observed characteristics including preservation of original stratigraphy and finer-grained basal (shearing) layers. Interpreting the formation and evolution of these structures is key to understanding the processes that occur after flank/sector detachment has commenced. A distinct element numerical modelling technique has been used to investigate the volcano avalanche emplacement processes. Particle bonding is introduced to a generalized flank collapse scenario; when stresses are overcome in the failed mass, the bond breaks. Material with pervasive bond breakage subsequently behaves as a granular material. This approach allows brittle discontinuities to emerge in the flow as the avalanche propagates through the runout space. Initial results are in good agreement with deposit structures observed in the field and in ASTER satellite imagery. These include the development of hummocky topography, toreva block formation and a progressive rounding of blocks of bonded particles. These blocks are present primarily on the surface of the subsequent deposit and decrease in size distally. Additionally, no particle bonds remain along the basal surface of the simulated deposit, implying the presence of a basal shearing layer, a mechanism believed responsible for long runouts in real world avalanches.

  1. Holocene history of deep-seated landsliding in the North Fork Stillaguamish River valley from surface roughness analysis, radiocarbon dating, and numerical landscape evolution modeling

    NASA Astrophysics Data System (ADS)

    Booth, Adam M.; LaHusen, Sean R.; Duvall, Alison R.; Montgomery, David R.

    2017-02-01

    Documenting spatial and temporal patterns of past landsliding is a challenging step in quantifying the effect of landslides on landscape evolution. While landslide inventories can map spatial distributions, lack of dateable material, landslide reactivations, or time, access, and cost constraints generally limit dating large numbers of landslides to analyze temporal patterns. Here we quantify the record of the Holocene history of deep-seated landsliding along a 25 km stretch of the North Fork Stillaguamish River valley, Washington State, USA, including the 2014 Oso landslide, which killed 43 people. We estimate the ages of more than 200 deep-seated landslides in glacial sediment by defining an empirical relationship between landslide deposit age from radiocarbon dating and landslide deposit surface roughness. We show that roughness systematically decreases with age as a function of topographic wavelength, consistent with models of disturbance-driven soil transport. The age-roughness model predicts a peak in landslide frequency at 1000 calibrated (cal) years B.P., with very few landslide deposits older than 7000 cal years B.P. or younger than 100 cal years B.P., likely reflecting a combination of preservation bias and a complex history of changing climate, base level, and seismic shaking in the study area. Most recent landslides have occurred where channels actively interact with the toes of hillslopes composed of glacial sediments, suggesting that lateral channel migration is a primary control on the location of large deep-seated landslides in the valley.

  2. 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

  3. Submarine landslides

    USGS Publications Warehouse

    Hampton, M.A.; Lee, H.J.; Locat, J.

    1996-01-01

    Landslides are common on inclined areas of the seafloor, particularly in environments where weak geologic materials such as rapidly deposited, finegrained sediment or fractured rock are subjected to strong environmental stresses such as earthquakes, large storm waves, and high internal pore pressures. Submarine landslides can involve huge amounts of material and can move great distances: slide volumes as large as 20,000 km3 and runout distances in excess of 140 km have been reported. They occur at locations where the downslope component of stress exceeds the resisting stress, causing movement along one or several concave to planar rupture surfaces. Some recent slides that originated nearshore and retrogressed back across the shoreline were conspicuous by their direct impact on human life and activities. Most known slides, however, occurred far from land in prehistoric time and were discovered by noting distinct to subtle characteristics, such as headwall scarps and displaced sediment or rock masses, on acoustic-reflection profiles and side-scan sonar images. Submarine landslides can be analyzed using the same mechanics principles as are used for occurrences on land. However, some loading mechanisms are unique, for example, storm waves, and some, such as earthquakes, can have greater impact. The potential for limited-deformation landslides to transform into sediment flows that can travel exceedingly long distances is related to the density of the slope-forming material and the amount of shear strength that is lost when the slope fails.

  4. 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.

  5. Deep-water seamounts in the NE Atlantic, sources of landslides-induced tsunamis: Slope stability analysis and tsunami numerical modelling

    NASA Astrophysics Data System (ADS)

    Baptista, M. A.; Omira, R.; Ramalho, I.; Vales, D.; Matias, L. M.; Terrinha, P.

    2015-12-01

    Submarine mass failures (SMFs) present one of the significant marine Geo-hazards. Their importance as contributors to tsunami hazard has been recognized over the last 20-30 years, but they are seldom considered in the evaluation of quantitative tsunami impact or in the design of warning strategies. This study aims to investigate the slope stability of the SMFs in the NE Atlantic, their companion tsunami and the associated hazard at the target coasts. It focuses on two major deep-water seamounts of the NE Atlantic, the Gorringe Bank and the Hirondelle, where evidences of large SMFs have been found. Slope stability analysis is often based on relationships between landslides and earthquakes. Here, within each considered seamount, slope failure potential is investigated through the pseudo-static method. This analysis allows establishing a relationship between the size of the SMF and the critical earthquake peak ground acceleration necessary to initiate it and therefore define the possible SMF scenarios. Numerical modelling of SMF-induced tsunami generation is then employed to test the tsunamigenic potential of each defined scenario. It is performed using a multi-layers viscous shallow-water model, where the lower layer represents the deformable slide that is assumed to be a viscous-incompressible fluid, and bounded by the upper layer of seawater assumed to be inviscid and incompressible. The propagation of tsunami waves is simulated employing non-linear shallow water equations. Results are presented in terms of: 1) slope stability curves that establish the relationship between the probable earthquake magnitudes and the possible sizes of SMFs, 2) possible SMF scenarios within each seamount, 3) potential of tsunami generation for each SMF, 4) tsunami coastal impact at target coasts. Results show that SMFs in the NE Atlantic have the potential of generating large tsunamis with significant impact along the surrounding coasts. Therefore, more attention must be accorded to

  6. 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

  7. A Quasi-Global Landslide Model Using Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Farahmand, A.; AghaKouchak, A.

    2012-12-01

    Each year, landslides cause thousands of casualties and billions of dollars in damages across the world. Landslides are triggered by heavy precipitation and/or earthquakes. Typically, Hurricanes and Typhoons lead to extensive rainfall over several days and thus, may trigger landslides. Thus far, various statistical, analytical and numerical approaches have been introduced to model landslides. The aim of this study is to develop a global landslide prediction model. In the first step, the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) landslide inventory along with satellite-based precipitation data, 250 m slope, land cover information are used to develop the model. This landslide model utilizes the power of Support Vector Machines (SVM), which is a learning algorithm that can classify landslide events. 70% of the NASA/GSFC landslide inventory data were used for model training and 30% for validation and verification. The results of 200 random sub-samples of available landslide observations (70% training and 30% validation) revealed that the suggested model predicted historical landslides reliably. The average error of 200 iterations of landslide prediction was estimated approximately 2%, with approximately 1% false landslide events. Efforts are underway to further develop this model into a global landslide prediction model.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. Mount Meager landslide flow history

    NASA Astrophysics Data System (ADS)

    Moretti, Laurent; Allstadt, Kate; Mangeney, Anne; Yann, capdeville; Eleonore, Stutzmann; François, Bouchut

    2014-05-01

    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

  18. Assessment of Landslide Hazards using Geophysical Tomography

    NASA Astrophysics Data System (ADS)

    Kostyanev, S.; Iliev, I.; Stefanov, P.; Stoeva, P.

    2003-04-01

    Landslides and unstable slopes are among the major natural and man-made hazards affecting manking and yet their causes, their consequences for human life and property, and possible strategies for mitigating their effect are not very well understood. We will note, that only in Bulgaria there are over thousand active landslides on populated and health resort areas. The material and social losses have not been calculated yet. But in preliminary data they are enormous.Numerous and dangerous are the landslides and unstable slopes in opencast coal-mines too. In this paper we offer methods for combined application of high resolution electrical resistivity) tomography and seismic ray tomography for characteristic of landslide hazards and unstable ones. The major aim here is to predict where and when landsliding will occur, establishing their variability in space and time, and appraising their impact on the natural and socio-economical environment. The above methods are applied for studing of concrete landslide in Bulgarian Black Sea and on some unstable slopes in an opencast coal-mine of Maritza-Iztok area. This combined application of electrical and seismic tomography for assessment of landslide hazard is very usefull.

  19. 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.

  20. Comparing landslide inventory maps

    NASA Astrophysics Data System (ADS)

    Galli, Mirco; Ardizzone, Francesca; Cardinali, Mauro; Guzzetti, Fausto; Reichenbach, Paola

    Landslide inventory maps are effective and easily understandable products for both experts, such as geomorphologists, and for non experts, including decision-makers, planners, and civil defense managers. Landslide inventories are essential to understand the evolution of landscapes, and to ascertain landslide susceptibility and hazard. Despite landslide maps being compiled every year in the word at different scales, limited efforts are made to critically compare landslide maps prepared using different techniques or by different investigators. Based on the experience gained in 20 years of landslide mapping in Italy, and on the limited literature on landslide inventory assessment, we propose a general framework for the quantitative comparison of landslide inventory maps. To test the proposed framework we exploit three inventory maps. The first map is a reconnaissance landslide inventory prepared for the Umbria region, in central Italy. The second map is a detailed geomorphological landslide map, also prepared for the Umbria region. The third map is a multi-temporal landslide inventory compiled for the Collazzone area, in central Umbria. Results of the experiment allow for establishing how well the individual inventories describe the location, type and abundance of landslides, to what extent the landslide maps can be used to determine the frequency-area statistics of the slope failures, and the significance of the inventory maps as predictors of landslide susceptibility. We further use the results obtained in the Collazzone area to estimate the quality and completeness of the two regional landslide inventory maps, and to outline general advantages and limitations of the techniques used to complete the inventories.

  1. 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.

  2. 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.

  3. 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.

  4. Road landslide information management and forecasting system base on GIS.

    PubMed

    Wang, Wei Dong; Du, Xiang Gang; Xie, Cui Ming

    2009-09-01

    Take account of the characters of road geological hazard and its supervision, it is very important to develop the Road Landslides Information Management and Forecasting System based on Geographic Information System (GIS). The paper presents the system objective, function, component modules and key techniques in the procedure of system development. The system, based on the spatial information and attribute information of road geological hazard, was developed and applied in Guizhou, a province of China where there are numerous and typical landslides. The manager of communication, using the system, can visually inquire all road landslides information based on regional road network or on the monitoring network of individual landslide. Furthermore, the system, integrated with mathematical prediction models and the GIS's strongpoint on spatial analyzing, can assess and predict landslide developing procedure according to the field monitoring data. Thus, it can efficiently assists the road construction or management units in making decision to control the landslides and to reduce human vulnerability.

  5. 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.

  6. 3-dimensional fabrication of soft energy harvesters

    NASA Astrophysics Data System (ADS)

    McKay, Thomas; Walters, Peter; Rossiter, Jonathan; O'Brien, Benjamin; Anderson, Iain

    2013-04-01

    Dielectric elastomer generators (DEG) provide an opportunity to harvest energy from low frequency and aperiodic sources. Because DEG are soft, deformable, high energy density generators, they can be coupled to complex structures such as the human body to harvest excess mechanical energy. However, DEG are typically constrained by a rigid frame and manufactured in a simple planar structure. This planar arrangement is unlikely to be optimal for harvesting from compliant and/or complex structures. In this paper we present a soft generator which is fabricated into a 3 Dimensional geometry. This capability will enable the 3-dimensional structure of a dielectric elastomer to be customised to the energy source, allowing efficient and/or non-invasive coupling. This paper demonstrates our first 3 dimensional generator which includes a diaphragm with a soft elastomer frame. When the generator was connected to a self-priming circuit and cyclically inflated, energy was accumulated in the system, demonstrated by an increased voltage. Our 3D generator promises a bright future for dielectric elastomers that will be customised for integration with complex and soft structures. In addition to customisable geometries, the 3D printing process may lend itself to fabricating large arrays of small generator units and for fabricating truly soft generators with excellent impedance matching to biological tissue. Thus comfortable, wearable energy harvesters are one step closer to reality.

  7. 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.

  8. PERSPECTIVE ON LANDSLIDE DAMS.

    USGS Publications Warehouse

    Schuster, Robert L.; Costa, John E.; ,

    1986-01-01

    The most common types of mass movements that form landslide dams are rock and soil slumps and slides; mud, debris, and earth flows: and rock and debris avalanches. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snow melt, and earthquakes. Most landslide dams are remarkable short-lived. In a sample of 63 documented cases, 22 percent of the landslide dams failed in less than 1 day after formation, and half failed within 10 days. Overtopping was by far the most frequent cause of landslide-dam failure. Backwater flooding behind landslide dams can inundate communities and valuable agricultural land. Floods from the failure of landslide dams are smaller than floods from constructed dams impounding bodies of water with the same potential energy, but larger than floods from failure of ice dams. Secondary effects of landslide-dam failures include additional landslides as reservoir levels drop rapidly, aggradation of valleys upstream and downstream of the dams, and avulsive channel changes downstream.

  9. Landslides as agents of diversity

    NASA Astrophysics Data System (ADS)

    Geertsema, Marten

    2016-04-01

    Landslides, often destructive and damaging, are also agents of change that introduce diversity to landscapes. I discuss landslide diversity at three levels: site diversity, soil diversity, and habitat diversity. There are many landslide types involving different materials and rates and styles of movement. Landscape diversity varies with different types of landslides. Landslides, at the same time depositional and erosional agents, influence sites by redistributing materials and changing microtopography. Eroded portions of landslides, with exposed parent material, revert to the initial stages of soil development and ecological succession. Landslides can also alter soil properties including, surface texture, chemistry and porosity. Landslides influence habitat diversity by creating ecosystem mosaics.

  10. Turbidite record of frequency and source of large volume (>100 km3) Canary Island landslides in the last 1.5 Ma: Implications for landslide triggers and geohazards

    NASA Astrophysics Data System (ADS)

    Hunt, J. E.; Wynn, R. B.; Talling, P. J.; Masson, D. G.

    2013-07-01

    During the last two decades, numerous studies have focused on resolving the landslide histories of the Canary Islands. Issues surrounding the preservation and dating of onshore and proximal submarine landslide deposits precludes accurate determination of event ages. However, submarine landslides often disaggregate and generate sediment gravity flows. Volcaniclastic turbidites sampled from Madeira Abyssal Plain piston cores represent a record of eight large-volume failures from the Western Canary Islands in the last 1.5 Ma. During this time, there is a mean recurrence rate of 200 ka, while the islands of El Hierro and Tenerife have individual landslide recurrences of 500 ka and 330 ka, respectively. Deposits from the 15 ka El Golfo landslide from El Hierro and 165 ka Icod landslide from Tenerife are examined. This study also identifies potential deposits associated with the Orotava (535 ka), Güímar (850 ka), and Rogues de García landslides (1.2 Ma) from Tenerife, El Julan (540 ka), and El Tiñor (1.05 Ma) landslides from El Hierro, and the Cumbre Nueva landslide (485 ka) from La Palma. Seven of eight landslides occurred during major deglaciations or subsequent interglacial periods, which represent 55% of the time. However, all of the studied landslides occur during or at the end of periods of protracted island volcanism, which generally represent 60% of the island histories. Although climate may precondition failures, it is suggested that volcanism presents a more viable preconditioning and trigger mechanism for Canary Island landslides.

  11. 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.

  12. 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.

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

    PubMed

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

    2014-03-04

    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.

  14. 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.

  15. Submarine landslides of the Southern California Borderland

    USGS Publications Warehouse

    Lee, H.J.; Greene, H. Gary; Edwards, B.D.; Fisher, M.A.; Normark, W.R.

    2009-01-01

    Conventional bathymetry, sidescan-sonar and seismic-reflection data, and recent, multibeam surveys of large parts of the Southern California Borderland disclose the presence of numerous submarine landslides. Most of these features are fairly small, with lateral dimensions less than ??2 km. In areas where multibeam surveys are available, only two large landslide complexes were identified on the mainland slope- Goleta slide in Santa Barbara Channel and Palos Verdes debris avalanche on the San Pedro Escarpment south of Palos Verdes Peninsula. Both of these complexes indicate repeated recurrences of catastrophic slope failure. Recurrence intervals are not well constrained but appear to be in the range of 7500 years for the Goleta slide. The most recent major activity of the Palos Verdes debris avalanche occurred roughly 7500 years ago. A small failure deposit in Santa Barbara Channel, the Gaviota mudflow, was perhaps caused by an 1812 earthquake. Most landslides in this region are probably triggered by earthquakes, although the larger failures were likely conditioned by other factors, such as oversteepening, development of shelf-edge deltas, and high fluid pressures. If a subsequent future landslide were to occur in the area of these large landslide complexes, a tsunami would probably result. Runup distances of 10 m over a 30-km-long stretch of the Santa Barbara coastline are predicted for a recurrence of the Goleta slide, and a runup of 3 m over a comparable stretch of the Los Angeles coastline is modeled for the Palos Verdes debris avalanche. ?? 2009 The Geological Society of America.

  16. 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

  17. 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.

  18. 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.

  19. Scientific visualization of 3-dimensional optimized stellarator configurations

    SciTech Connect

    Spong, D.A.

    1998-01-01

    The design techniques and physics analysis of modern stellarator configurations for magnetic fusion research rely heavily on high performance computing and simulation. Stellarators, which are fundamentally 3-dimensional in nature, offer significantly more design flexibility than more symmetric devices such as the tokamak. By varying the outer boundary shape of the plasma, a variety of physics features, such as transport, stability, and heating efficiency can be optimized. Scientific visualization techniques are an important adjunct to this effort as they provide a necessary ergonomic link between the numerical results and the intuition of the human researcher. The authors have developed a variety of visualization techniques for stellarators which both facilitate the design optimization process and allow the physics simulations to be more readily understood.

  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. Landslide-generated tsunamis at Réunion Island

    NASA Astrophysics Data System (ADS)

    Kelfoun, Karim; Giachetti, Thomas; Labazuy, Philippe

    2010-10-01

    Landslides that occur on oceanic volcanoes can reach the sea and trigger catastrophic tsunamis. Réunion Island has been the location of numerous huge landslides involving tens to hundreds of cubic kilometers of material. We use a new two-fluid (seawater and landslide) numerical model to estimate the wave amplitudes and the propagation of tsunamis associated with landslide events on Réunion Island. A 10 km3 landslide from the eastern flank of Piton de la Fournaise volcano would lift the water surface by about 150 m where it entered the sea. The wave thus generated would reach Saint-Denis, the capital of Réunion Island (population of about 150,000 people), in only 12 min, with an amplitude of more than 10 m, and would reach Mauritius Island in 18 min. Although Mauritius is located about 175 km from the impact, waves reaching its coast would be greater than those for Réunion Island. This is due to the initial shape of the wave, and its propagation normal to the coast at Mauritius but generally coast-parallel at Réunion Island. A submarine landslide of the coastal shelf of 2 km3, would trigger a ˜40 m high wave that would severely affect the proximal coast in the western part of Réunion Island. For a landslide of the shelf of only 0.5 km3, waves of about 2 m in amplitude would affect the proximal coast.

  3. 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.

  4. Colluvium supply in humid regions limits the frequency of storm-triggered landslides

    PubMed Central

    Parker, Robert N.; Hales, Tristram C.; Mudd, Simon M.; Grieve, Stuart W. D.; Constantine, José A.

    2016-01-01

    Shallow landslides, triggered by extreme rainfall, are a significant hazard in mountainous landscapes. The hazard posed by shallow landslides depends on the availability and strength of colluvial material in landslide source areas and the frequency and intensity of extreme rainfall events. Here we investigate how the time taken to accumulate colluvium affects landslide triggering rate in the Southern Appalachian Mountains, USA and how this may affect future landslide hazards. We calculated the failure potential of 283 hollows by comparing colluvium depths to the minimum (critical) soil depth required for landslide initiation in each hollow. Our data show that most hollow soil depths are close to their critical depth, with 62% of hollows having soils that are too thin to fail. Our results, supported by numerical modeling, reveal that landslide frequency in many humid landscapes may be insensitive to projected changes in the frequency of intense rainfall events. PMID:27688039

  5. Colluvium supply in humid regions limits the frequency of storm-triggered landslides

    NASA Astrophysics Data System (ADS)

    Parker, Robert N.; Hales, Tristram C.; Mudd, Simon M.; Grieve, Stuart W. D.; Constantine, José A.

    2016-09-01

    Shallow landslides, triggered by extreme rainfall, are a significant hazard in mountainous landscapes. The hazard posed by shallow landslides depends on the availability and strength of colluvial material in landslide source areas and the frequency and intensity of extreme rainfall events. Here we investigate how the time taken to accumulate colluvium affects landslide triggering rate in the Southern Appalachian Mountains, USA and how this may affect future landslide hazards. We calculated the failure potential of 283 hollows by comparing colluvium depths to the minimum (critical) soil depth required for landslide initiation in each hollow. Our data show that most hollow soil depths are close to their critical depth, with 62% of hollows having soils that are too thin to fail. Our results, supported by numerical modeling, reveal that landslide frequency in many humid landscapes may be insensitive to projected changes in the frequency of intense rainfall events.

  6. Colluvium supply in humid regions limits the frequency of storm-triggered landslides.

    PubMed

    Parker, Robert N; Hales, Tristram C; Mudd, Simon M; Grieve, Stuart W D; Constantine, José A

    2016-09-30

    Shallow landslides, triggered by extreme rainfall, are a significant hazard in mountainous landscapes. The hazard posed by shallow landslides depends on the availability and strength of colluvial material in landslide source areas and the frequency and intensity of extreme rainfall events. Here we investigate how the time taken to accumulate colluvium affects landslide triggering rate in the Southern Appalachian Mountains, USA and how this may affect future landslide hazards. We calculated the failure potential of 283 hollows by comparing colluvium depths to the minimum (critical) soil depth required for landslide initiation in each hollow. Our data show that most hollow soil depths are close to their critical depth, with 62% of hollows having soils that are too thin to fail. Our results, supported by numerical modeling, reveal that landslide frequency in many humid landscapes may be insensitive to projected changes in the frequency of intense rainfall events.

  7. Large scale landslide mud flow modeling, simulation, and comparison with observations

    NASA Astrophysics Data System (ADS)

    Liu, F.; Shao, X.; Zhang, B.

    2012-12-01

    Landslide is a catastrophic natural event. Modeling, simulation, and early warning of landslide event can protect the safety of lives and properties. Therefore, study of landslide bears important scientific and practical value. In this research, we constructed a high performance parallel fluid dynamics model to study large scale landslide transport and evolution process. This model solves shallow water equation derived from 3 dimensional Euler equations in Cartesian coordinate system. Based on bottom topography, initial condition, bottom friction, and mudflow viscosity coefficient, density and other parameters, this model predicts landslide transport process and deposition distribution. Using 3 dimension bottom topography data from an digital elevation model in Zhou Qu area, this model produces the onset, transport and deposition process happened during Zhou Qu landslide. It also calculates spatial and temporal distribution of the mud flow transportation route, deposition depth, and kinematic energy of the event. This model together with an early warning system can lead to significant improvement to construction planning in landslide susceptible area.; Zhou Qu topography from Digital Elevation Model ; Modeling result from PLM (parallel landslide model)

  8. 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.

  9. Geographic relations of landslide distribution and assessment of landslide hazards in the Blanco, Cibuco, and Coamo basins, Puerto Rico

    USGS Publications Warehouse

    Larsen, M.C.; Torres-Sanchez, A. J.

    1996-01-01

    Landslide occurrence is common in mountainous areas of Puerto Rico where mean annual rainfall and the frequency of intense storms are high and hillslopes are steep. Each year, landslides cause extensive damage to property and occasionally result in loss of life. Landslide maps developed from 1:20,000 scale aerial photographs in combination with a computerized geographic information system were used to evaluate the landslide potential in the Blanco, Cibuco, and Coamo Basins of Puerto Rico. These basins, ranging in surface area from 276 to 350 square kilometers, are described in this report. The basins represent a broad range of the climatologic, geographic, and geologic conditions that occur in Puerto Rico. In addition, a variety of landslide types were documented. Rainfall-triggered debris flows, shallow soil slips, and slumps were most abundant. The most important temporal control on landslide occurrence in Puerto Rico is storm rainfall. Forty-one storms triggered widespread landsliding about 1 to 2 times per year during the last three decades. These storms were frequently of 1 to 2 days duration in which, on average, several hundred millimeters of rainfall triggered tens to hundreds of landslides in the central mountains. Most of these storms were tropical disturbances that occurred during the hurricane season of June through November. Land use and the topographic characteristics of hillslope angle, elevation, and aspect are the most important spatial controls governing landslide frequency. Hillslopes in the study area that have been anthropogenically modified, exceed 12 degrees in gradient and about 350 meters in elevation, and face the east-northeast are most prone to landsliding. Bedrock geology and soil order seem less important in the determination of landslide frequency, at least when considered at a generalized level. A rainfall accumulation-duration relation for the triggering of numerous landslides throughout the central mountains, and a set of

  10. 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.

  11. 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.

  12. 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

  13. Fast landslides travelling on permafrost with application to Mars: preliminary modelling studies

    NASA Astrophysics Data System (ADS)

    De Blasio, F. V.

    2013-09-01

    Long-runout landslides on Mars and especially in Valles Marineris present similarities with terrestrial landslides collapsing on glaciers. Because it is much unlikely that ice, if any, has remained exposed in the equatorial Valles Marineris for a time span >2 Gy, this could indicate that ancient failures occurred on subsurface ice. It would be interesting to develop simulation codes for landslides in permafrost and compare the numerical prediction to case studies on the Martian surface.

  14. Improving Spatial Prediction of Shallow Rainfall-induced Landslides

    NASA Astrophysics Data System (ADS)

    Baum, R. L.; Godt, J. W.; Coe, J. A.

    2009-12-01

    landslides modeled in 2-D and 3-D are preferentially found within areas of straight or concave profile (hollows). These predicted landslides cannot cross into adjacent convex areas, because the line of thrust must remain within a modeled landslide mass to prevent interslice or intercell tension and numerical instability. Physically, tension would cause the mass to separate. Consequently, source areas of shallow landslides computed using 2-D or 3-D methods are likely to be confined to individual concavities, whereas observed source areas may be much larger as a result of simultaneous or progressive failure that cause neighboring slides to coalesce. Using 2-D or 3-D analyses to predict landslide size and location reduces spurious clusters of unstable cells and improves accuracy.

  15. Submarine landslides hazard offshore Israel

    NASA Astrophysics Data System (ADS)

    Katz, Oded

    2016-04-01

    Submarine landslides pose significant natural hazards. They can damage seafloor infrastructure, such as that used to recover oil and gas or seafloor telecommunication cables, and even generate tsunamis. We recently mapped 447 submarine landslides across the east Mediterranean continental slope, offshore Israel (hereafter the studied area). The mapped landslides are found at water depths of 130 m to 1,000 m and their volume ranges 10-5 - 100 km3. Landslide scars are typically related to a critical slope angle of >4° . Landslides at the northern part of the studied area are spatially associated with fault scarps and are smaller than the ones on the southern part. In this work we evaluate the potential hazard to population and to on- and off- shore facilities posed by submarine landslides across the studied area. We integrate three independent probabilities: (1) the probability for a landslide event of a given volume, based on the size distribution of the mapped landslides; (2) the probability for a landslide event in a given time, based on the reoccurrence time of triggering earthquakes with M >7, and on a 50,000 years general time frame derived from submarine landslides identified across the Mediterranean Sea; (3) the probability for a landslide event in a given area, based on the distribution of slopes exceeding the critical angle. Overall, the fraction of potentially destructive landslides (size > 0.1 km3) is small, 0.05. Thus, considering typical planning time scales of less than 100 years, the calculated hazard is only moderate. The small fraction of landslides with tsunamogenic potential (size > 1 km3), suggests that the hazard for landslide-induced tsunamis along the open slope part of the studied area is small. Landslides in the southern part of the studied area are larger and thus present a somewhat bigger potential source of tsunami waves.

  16. 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

  17. 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.

  18. 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.

  19. The Manti, Utah, landslide

    USGS Publications Warehouse

    Fleming, R.W.; Johnson, R.B.; Schuster, R.L.; Williams, G.P.

    1988-01-01

    PART A: The Manti landslide is in Manti Canyon on the west side of the Wasatch Plateau in central Utah. In early June 1974, coincident with the melting of a snowpack, a rock slump/debris flow occurred on the south rim of Manti Canyon. Part of the slumped material mixed with meltwater and mobilized into a series of debris flows that traveled down the slope a distance of as much as 1.2 km. Most of the flows were deposited either at the base of the steep rocks of the canyon rim or at the site of an old, silted reservoir. A small part of the debris flow deposit stopped on the head of the very large, relatively inactive Manti landslide. The upper part of the landslide began moving as cracks propagated downslope. A little more than a year later, August 1975, movement extended the full length of the old landslide, and about 19 million m 3 of debris about 3 km long and as much as 800 m wide threatened to block the canyon. The upper part of the landslide apparently had moved small amounts between 1939 and 1974. This part of the landslide, identifiable on pre-1974 aerial photographs, consisted of well-defined linears on the landslide flanks and two large internal toe bulges about 2 km downslope from the head. The abrupt reactivation in 1974 proceeded quickly after the debris flows had provided a surcharge in the head and crown area. Movement propagated downslope at 4-5 m/h for the first few days following reactivation. During 1974, the reactivation probably encompassed all the parts of the landslide that had moved small amounts between 1939 and 1974. Movement nearly or completely stopped during the winter of 1974-75, but began again in the spring of 1975. The landslide enlarged from the flanks of the internal toe bulges to Manti Creek at a rate of 2-3 m/h. Movement stopped again during the winter of 1975-76 and began again in the spring of 1976. Thereafter, the displacements have been small compared to earlier. The displacement rates for the landslide were variable depending

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Large landslides from oceanic volcanoes

    USGS Publications Warehouse

    Holcomb, R.T.; Searle, R.C.

    1991-01-01

    Large landslides are ubiquitous around the submarine flanks of Hawaiian volcanoes, and GLORIA has also revealed large landslides offshore from Tristan da Cunha and El Hierro. On both of the latter islands, steep flanks formerly attributed to tilting or marine erosion have been reinterpreted as landslide headwalls mantled by younger lava flows. These landslides occur in a wide range of settings and probably represent only a small sample from a large population. They may explain the large volumes of archipelagic aprons and the stellate shapes of many oceanic volcanoes. Large landslides and associated tsunamis pose hazards to many islands. -from Authors

  5. Chaotic Advection in a Bounded 3-Dimensional Potential Flow

    NASA Astrophysics Data System (ADS)

    Metcalfe, Guy; Smith, Lachlan; Lester, Daniel

    2012-11-01

    3-dimensional potential, or Darcy flows, are central to understanding and designing laminar transport in porous media; however, chaotic advection in 3-dimensional, volume-preserving flows is still not well understood. We show results of advecting passive scalars in a transient 3-dimensional potential flow that consists of a steady dipole flow and periodic reorientation. Even for the most symmetric reorientation protocol, neither of the two invarients of the motion are conserved; however, one invarient is closely shadowed by a surface of revolution constructed from particle paths of the steady flow, creating in practice an adiabatic surface. A consequence is that chaotic regions cover 3-dimensional space, though tubular regular regions are still transport barriers. This appears to be a new mechanism generating 3-dimensional chaotic orbits. These results contast with the experimental and theoretical results for chaotic scalar transport in 2-dimensional Darcy flows. Wiggins, J. Fluid Mech. 654 (2010).

  6. Landslide inventories: The essential part of seismic landslide hazard analyses

    USGS Publications Warehouse

    Harp, E.L.; Keefer, D.K.; Sato, H.P.; Yagi, H.

    2011-01-01

    A detailed and accurate landslide inventory is an essential part of seismic landslide hazard analysis. An ideal inventory would cover the entire area affected by an earthquake and include all of the landslides that are possible to detect down to sizes of 1-5. m in length. The landslides must also be located accurately and mapped as polygons depicting their true shapes. Such mapped landslide distributions can then be used to perform seismic landslide hazard analysis and other quantitative analyses. Detailed inventory maps of landslide triggered by earthquakes began in the early 1960s with the use of aerial photography. In recent years, advances in technology have resulted in the accessibility of satellite imagery with sufficiently high resolution to identify and map all but the smallest of landslides triggered by a seismic event. With this ability to view any area of the globe, we can acquire imagery for any earthquake that triggers significant numbers of landslides. However, a common problem of incomplete coverage of the full distributions of landslides has emerged along with the advent of high resolution satellite imagery. ?? 2010.

  7. 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.

  8. Suggested nomenclature for landslides

    USGS Publications Warehouse

    Cruden, D.M.; Novograd, S.; Pilot, G.A.; Krauter, E.; Bhandari, R.K.; Cotecchia, V.; Nakamura, H.; Okagbue, C.O.; Zhuoyuan , Zhang; Hutchinson, J.N.; Varnes, D.J.; Ter-Stepanian, G.I.

    1990-01-01

    The IAEG Commission on Landslides and other Mass Movements on Slopes has proposed English and French names for 19 identifiable features of slope movements and for 7 dimensions of those features. The Commission intends to publish this list in other languages and to supplement and revise it from time to time.

  9. Thermal crosstalk in 3-dimensional RRAM crossbar array

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    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.

  10. 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

  11. 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

    2015-08-27

    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.

  12. Identifying a large landslide with small displacements in a zone of coseismic tectonic deformation; the Villa Del Monte landslide triggered by the 1989 Loma Prieta, California, earthquake

    USGS Publications Warehouse

    Keefer, David K.; Harp, Edwin L.; Griggs, Gary B.; Evans, Stephen G.; DeGraff, Jerome V.

    2002-01-01

    The Villa Del Monte landslide was one of 20 large and complex landslides triggered by the 1989 LomaPrieta, California, earthquake in a zone of pervasive coseismicground cracking near the fault rupture. The landslide was approximately 980 m long, 870 m wide, and encompassed an area of approximately 68 ha. Drilling data suggested that movement may have extended to depths as great as 85 m below the ground surface. Even though the landslide moved <1 m, it caused substantial damage to numerous dwellings and other structures, primarily as a result of differential displacements and internal Assuring. Surface cracks, scarps, and compression features delineating the Villa Del Monte landslide were discontinuous, probably because coseismic displacements were small; such discontinuous features were also characteristic of the other large, coseismic landslides in the area, which also moved only short distances during the earthquake. Because features marking landslide boundaries were discontinuous and because other types of coseismic ground cracks were widespread in the area, identification of the landslides required detailed mapping and analysis. Recognition that landslides such as that at Villa Del Monte may occur near earthquake-generating fault ruptures should aid in future hazard evaluations of areas along active faults.

  13. 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

  14. 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.

  15. Optimization of 3-dimensional imaging of the breast region with 3-dimensional laser scanners.

    PubMed

    Kovacs, Laszlo; Yassouridis, Alexander; Zimmermann, Alexander; Brockmann, Gernot; Wöhnl, Antonia; Blaschke, Matthias; Eder, Maximilian; Schwenzer-Zimmerer, Katja; Rosenberg, Robert; Papadopulos, Nikolaos A; Biemer, Edgar

    2006-03-01

    The anatomic conditions of the female breast require imaging the breast region 3-dimensionally in a normal standing position for quality assurance and for surgery planning or surgery simulation. The goal of this work was to optimize the imaging technology for the mammary region with a 3-dimensional (3D) laser scanner, to evaluate the precision and accuracy of the method, and to allow optimum data reproducibility. Avoiding the influence of biotic factors, such as mobility, we tested the most favorable imaging technology on dummy models for scanner-related factors such as the scanner position in comparison with the torso and the number of scanners and single shots. The influence of different factors of the breast region, such as different breast shapes or premarking of anatomic landmarks, was also first investigated on dummies. The findings from the dummy models were then compared with investigations on test persons, and the accuracy of measurements on the virtual models was compared with a coincidence analysis of the manually measured values. The best precision and accuracy of breast region measurements were achieved when landmarks were marked before taking the shots and when shots at 30 degrees left and 30 degrees right, relative to the sagittal line, were taken with 2 connected scanners mounted with a +10-degree upward angle. However, the precision of the measurements on test persons was significantly lower than those measured on dummies. Our findings show that the correct settings for 3D imaging of the breast region with a laser scanner can achieve an acceptable degree of accuracy and reproducibility.

  16. 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

  17. 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.

  18. A suggested method for reporting a landslide

    USGS Publications Warehouse

    Fell, Robin; Lacerda, W.; Cruden, D.M.; Evans, S.G.; LaRochelle, P.; Martinez, Fernando; Beltran, Lisandro; Jesenak, J.; Novograd, S.; Krauter, E.; Slunga, E.; Pilot, G.A.; Brand, E.W.; Farkas, J.; Bhandari, R.K.; Cotecchia, V.; Esu, Franco; Fujita, H.; Nakamura, H.; Sassa, K.; Ting, W.H.; Salt, Graham; Janbu, Nilmar; Nespak, A.M.; Gongxian, Wang; Zhuoyuan , Zhang; Michelena, R.; Popescu, Mihai; Viberg, Leif; Bonnard, C.; Hutchinson, J.N.; Einstein , H.H.; Schuster, R.L.; Varnes, D.J.; Ter-Martiros­ian, Z.G.; Ter-Stepanian, G.I.; Anagnosti, P.; Hashizume, M.; Watanabe, Masayuki

    1990-01-01

    The Landslide Report is a Suggested Method developed by the International Geotechnical Societies' UNESCO Working Party on World Landslide Inventory for reporting the position, date, type, geometry, volume and damage of significant landslides.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Landslide and debris-flow hazard analysis and prediction using GIS in Minamata Hougawachi area, Japan

    NASA Astrophysics Data System (ADS)

    Wang, Chunxiang; Esaki, Tetsuro; Xie, Mowen; Qiu, Cheng

    2006-10-01

    On July 20, 2003, following a short duration of heavy rainfall, a debris-flow disaster occurred in the Minamata Hougawachi area, Kumamoto Prefecture, Japan. This disaster was triggered by a landslide. In order to assess the landslide and debris-flow hazard potential of this mountainous region, the study of historic landslides is critical. The objective of the study is to couple 3D slope-stability analysis models and 2D numerical simulation of debris flow within a geographical information systems in order to identity the potential landslide-hazard area. Based on field observations, the failure mechanism of the past landslide is analyzed and the mechanical parameters for 3D slope-stability analysis are calculated from the historic landslide. Then, to locate potential new landslides, the studied area is divided into slope units. Based on 3D slope-stability analysis models and on Monte Carlo simulation, the spots of potential landslides are identified. Finally, we propose a depth-averaged 2D numerical model, in which the debris and water mixture is assumed to be a uniform continuous, incompressible, unsteady Newtonian fluid. The method accurately models the historic debris flow. According to the 2D numerical simulation, the results of the debris-flow model, including the potentially inundated areas, are analyzed, and potentially affected houses, river and road are mapped.

  5. 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.

  6. Magnitude and Recurrence of Submarine Landslides: Active vs. Passive Margins

    NASA Astrophysics Data System (ADS)

    Urgeles, Roger; Camerlenghi, Angelo

    2016-04-01

    Submarine landslides are ubiquitous along Mediterranean continental margins. With the aim of understanding mass-wasting processes and related hazard at the scale of a large marine basin encompassing multiple geological settings, we have compiled data on their geometry, age, and trigger mechanism with a geographic information system. The distribution of submarine landslides in the Mediterranean reveals that major deltaic wedges have a higher density of large submarine landslides, while tectonically active margins are characterized by relatively small failures. In all areas, landslide size distributions display power law scaling for landslides > 1 km3. We find consistent differences on the exponent of the power law (θ) depending on the tectonic setting. Active margins present steep slopes of the frequency-magnitude relationship while passive margins tend to display gentler slopes. This pattern likely responds to the common view that tectonically active margins have numerous but small failures, while passive margins have larger but fewer failures. Available age information suggests that failures exceeding 1000 km3 are infrequent and may recur every ~40 kyr. Smaller failures that can still cause significant damage might be relatively frequent (failures > 1 km3 may recur every 40 years). The database highlights that our knowledge of submarine landslide activity with time is limited to a few tens of thousands of years. Available data suggest that submarine landslides may preferentially occur during lowstand periods, but no firm conclusion can be made on this respect, as only 70 landslides (out of 696 in the database) have relatively accurate age determinations. The temporal pattern and changes in frequency-magnitude distribution suggest that sedimentation patterns and pore pressure development have had a major role in triggering slope failures and control the sediment flux from mass wasting to the deep basin.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. An application of adaptive neuro-fuzzy inference system to landslide susceptibility mapping (Klang valley, Malaysia)

    NASA Astrophysics Data System (ADS)

    Sezer, Ebru; Pradhan, Biswajeet; Gokceoglu, Candan

    2010-05-01

    Landslides are one of the recurrent natural hazard problems throughout most of Malaysia. Recently, the Klang Valley area of Selangor state has faced numerous landslide and mudflow events and much damage occurred in these areas. However, only little effort has been made to assess or predict these events which resulted in serious damages. Through scientific analyses of these landslides, one can assess and predict landslide-susceptible areas and even the events as such, and thus reduce landslide damages through proper preparation and/or mitigation. For this reason , the purpose of the present paper is to produce landslide susceptibility maps of a part of the Klang Valley areas in Malaysia by employing the results of the adaptive neuro-fuzzy inference system (ANFIS) analyses. Landslide locations in the study area were identified by interpreting aerial photographs and satellite images, supported by extensive field surveys. Landsat TM satellite imagery was used to map vegetation index. Maps of topography, lineaments and NDVI were constructed from the spatial datasets. Seven landslide conditioning factors such as altitude, slope angle, plan curvature, distance from drainage, soil type, distance from faults and NDVI were extracted from the spatial database. These factors were analyzed using an ANFIS to construct the landslide susceptibility maps. During the model development works, total 5 landslide susceptibility models were obtained by using ANFIS results. For verification, the results of the analyses were then compared with the field-verified landslide locations. Additionally, the ROC curves for all landslide susceptibility models were drawn and the area under curve values was calculated. Landslide locations were used to validate results of the landslide susceptibility map and the verification results showed 98% accuracy for the model 5 employing all parameters produced in the present study as the landslide conditioning factors. The validation results showed sufficient

  14. Prediction of Rainfall-Induced Landslides

    NASA Astrophysics Data System (ADS)

    Nadim, F.; Sandersen, F.

    2009-12-01

    -mum intensity of rain within a short period of time (1-3 hours) during a storm is most critical for triggering of debris flows. Therefore empirical methods developed for prediction of initiation of debris flows include both long-duration and short-duration rain-fall. More recent research has focused on the spatial distribution of unstable areas and on better spatial resolution of the occurrence of landslide-triggering precipitation events. Spatial distribution can be assessed by analyzing the stability conditions for shallow landslides if reasonable estimates of strength parameters are available. In general, two different approaches may be adopted for the assessment of threshold values for rainfall-induced landslides: empirical methods that are based on past observations and statistical analyses, and numerical analyses that are based on geo-mechanical modelling. The former approach together with very short-term weather forecasting (now-casting) are commonly used in the design of early warning systems for debris flows.

  15. 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

  16. 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.

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

    USGS Publications Warehouse

    Keefer, David K.

    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.

  18. 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

  19. Evaluation of flood and landslide risk to the population of Italy.

    PubMed

    Guzzetti, Fausto; Stark, Colin P; Salvati, Paola

    2005-07-01

    We have compiled a database of floods and landslides that occurred in Italy between AD 1279 and 2002 and caused deaths, missing persons, injuries, and homelessness. Analysis of the database indicates that more than 50,593 people died, went missing, or were injured in 2580 flood and landslide events. Harmful events were inventoried in 26.3% of the 8103 Italian municipalities. Fatal events were most frequent in the Alpine regions of northern Italy and were caused by both floods and landslides. In southern Italy, landslides were the principal agents of fatalities and were most numerous in the Campania region. Casualties were most frequent in the autumn. Fast-moving landslides, including rock falls, rockslides, rock avalanches, and debris flows, caused the largest number of deaths. In order to assess the overall risk posed by these processes, we merged the historical catalogs and identified 2682 "hydrogeomorphological" events that triggered single or multiple landslides and floods. We estimated individual risk through the calculation of mortality rates for both floods and landslides and compared these rates to the death rates for other natural, medical, and human-induced hazards in Italy. We used the frequency distribution of events with fatalities to ascertain the magnitude and frequency of the societal risks posed by floods and landslides. We quantified these risks in a Bayesian model that describes the probabilities of fatal flood and landslide events in Italy.

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

    PubMed

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

    2014-11-01

    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.

  1. The National Landslide Information Center; data to reduce landslide damage

    USGS Publications Warehouse

    Brown, W. M.

    1992-01-01

    In a world of persistent and increasing construction on and occupation of hillslopes, canyons, and coastal bluffs, landslides are exacting an inexorable toll of human life and economic loss. In the 1980's, massive landslides disasters occurred throughout the world, many in regions where such disasters were historically unprecedented, or where their potential was forgotten or disregarded. by present generations. In some cases, large populations had moved onto unstable lands before renewed landslide activity. For example, the San Francisco Bay region in population between 1955 and 1982, and much of the new development occurred on hillsides and in canyons. Major rainstorms in both 1955 and 1982 produced abundant landslides throughout the region, but the landslides in 1982 proved much more devastating than those in 1955 because of the increased population density on sloping ground. Similar situations persist in many other population centers surrounded by hills and mountains, such as Rio de Janeiro, Hong Kong, and Los Angeles. 

  2. Landslide size distribution in seismic areas

    NASA Astrophysics Data System (ADS)

    Valagussa, Andrea; Frattini, Paolo; Crosta, Giovanni B.

    2015-04-01

    In seismic areas, the analysis of the landslides size distribution with the distance from the seismic source is very important for hazard zoning and land planning. From numerical modelling (Bourdeau et al., 2004), it has been observed that the area of the sliding mass tends to increase with the ground-motion amplitude up to a certain threshold input acceleration. This has been also observed empirically for the 1989 Loma Prieta earthquake (Keefer and Manson, 1998) and 1999 Chi Chi earthquake (Khazai and Sitar, 2003). Based on this, it possible to assume that the landslide size decreases with the increase of the distance from the seismic source. In this research, we analysed six earthquakes-induced landslides inventories (Papua New Guinea Earthquake, 1993; Northridge Earthquake, 1994; Niigata-Chuetsu Earthquake 2004; Iwate-Miyagi Nairiku Earthquake, 2008; Wenchuan Earthquake, 2008; Tohoku Earthquake, 2011) with a magnitude ranging between 6.6 and 9.0 Mw. For each earthquake, we first analysed the size of landslides as a function of different factors such as the lithology, the PGA, the relief, the distance from the seismic sources (both fault and epicentre). Then, we analysed the magnitude frequency curves for different distances from the source area and for each lithology. We found that a clear relationship between the size distribution and the distance from the seismic source is not evident, probably due to the combined effect of the different influencing factors and to the non-linear relationship between the ground-motion intensity and the distance from the seismic source.

  3. 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

  4. 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.

  5. Nature and timing of large landslides within an active orogen, eastern Pamir, China

    NASA Astrophysics Data System (ADS)

    Yuan, Zhaode; Chen, Jie; Owen, Lewis A.; Hedrick, Kathryn A.; Caffee, Marc W.; Li, Wenqiao; Schoenbohm, Lindsay M.; Robinson, Alexander C.

    2013-01-01

    Large-scale landsliding (involving ≫ 106 m3 in volume) is important in landscape development in high mountains. To assess the importance of large landslides in high mountains, four large landslides (Bulunkou, Muztagh, Taheman, and Yimake) were mapped in the NE Chinese Pamir at the westernmost end of the Himalayan-Tibetan orogen and dated using 10Be terrestrial cosmogenic nuclides. The Bulunkou landslide at the southernmost end of Muji Valley is composed of ~ 1.7 × 107 m3 of landslide debris and has an age of 2.0 ± 0.1 ka. The Muztagh landslide, located on the SW side of the massif Muztagh Ata, is composed of ~ 4.7 × 108 m3 of debris, and has an age of 14.3 ± 0.8 ka. The Taheman landslide, located south of Muztagh Ata, is composed of ~ 2.6 × 108 m3 of landslide debris and has an age of 6.8 ± 0.2 ka. The Yimake landslide, on the northern frontal range of the Pamir at the southwestern end of the Tarim basin, is composed of ~ 1.4 × 109 m3 of landslide debris and has an age of 7.1 ± 0.6 ka. Two other large landslides are present in the region, the Aerpa Aigezi (on a tributary of the Gez River) and the Bile Jiyi (on the Yarkand River) landslides, and are composed of ~ 1.6 × 107 m3 and ~ 5.2 × 106 m3 of landslide debris, respectively. However, the Aerpa Aigezi and Bile Jiyi landslides were not studied in as much detail or dated because of their inaccessibility. Given the tectonically active nature of this region, with numerous active faults, and the morphology of the landslides, these landslides were likely triggered by earthquakes. However, other causes — including long-term increased precipitation and geologic bedrock structure — could be important contributing factors in their formation.

  6. 3-Dimensional wireless sensor network localization: A review

    NASA Astrophysics Data System (ADS)

    Najib, Yasmeen Nadhirah Ahmad; Daud, Hanita; Aziz, Azrina Abd; Razali, Radzuan

    2016-11-01

    The proliferation of wireless sensor network (WSN) has shifted the focus to 3-Dimensional geometry rather than 2-Dimensional geometry. Since exact location of sensors has been the fundamental issue in wireless sensor network, node localization is essential for any wireless sensor network applications. Most algorithms mainly focus on 2-Dimensional geometry, where the application of this algorithm will decrease the accuracy on 3-Dimensional geometry. The low rank attribute in WSN's node estimation makes the application of nuclear norm minimization as a viable solution for dimensionality reduction problems. This research proposes a novel localization algorithm for 3-Dimensional WSN which is nuclear norm minimization. The node localization is formulated via Euclidean Distance Matrix (EDM) and is then optimized using Nuclear-Norm Minimization (NNM).

  7. Landslides Triggered by the 12 May 2008, M 7.9 Wenchuan, China Earthquake

    NASA Astrophysics Data System (ADS)

    Harp, E.; Jibson, R.; Godt, J.

    2009-04-01

    The 12 May 2008, M 7.9 Wenchuan earthquake in eastern Sichuan Province of China triggered tens of thousands of rock falls, rock slides, rock avalanches, and deep, complex, landslides. Of the approximately 87,000 deaths caused by the earthquake, more than 20,000 have been attributed to landsides. Numerous villages were buried by large landslides. Air-blasts resulting from the rapid failure and movement of landslides were observed and documented from numerous eye-witness accounts. More than 100 landslide-dammed lakes were created by the earthquake, 33 of which were evaluated to determine if spillway construction was necessary to minimize flooding by future breaching of the landslide dams. Spillways were ultimately constructed on at least 16 landslide dams. Preliminary observations in the field and from satellite imagery indicate that the most common types of landslides were rock falls and rock slides that ranged in size from several hundred cubic meters to several hundred thousand cubic meters in volume. There were hundreds to perhaps as many as one thousand landslides exceeding 1 million cubic meters in volume. The largest landslide identified using Jaxa's Alos/Prism satellite imagery (2.5 m resolution) is nearly 1 billion cubic meters in volume and is located approximately 12 km north-northeast of the city of Hanwang. This landslide appears to have resulted from the failure of a 1.5-km section of ridge crest that now occupies most of the adjacent valley to the northeast; its toe spills over the next ridge crest to the northeast. The satellite imagery of 4 June 2008 shows two small lakes dammed by the slide debris. Within the mountainous areas in the near-field zone of shaking, rock slides dammed chains of lakes in many drainages. Sections of streams 2-3 km long have been completely covered by rock debris as of the 4 June imagery The debris from the triggered landslides is being redistributed rapidly by post-earthquake rainfall. A 100-year rainstorm in September

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Lituya Bay Landslide Impact Generated Mega-Tsunami 50th Anniversary

    NASA Astrophysics Data System (ADS)

    Fritz, Hermann M.; Mohammed, Fahad; Yoo, Jeseon

    2009-02-01

    On July 10, 1958, an earthquake Mw 8.3 along the Fairweather fault triggered a major subaerial landslide into Gilbert Inlet at the head of Lituya Bay on the southern coast of Alaska. The landslide impacted the water at high speed generating a giant tsunami and the highest wave runup in recorded history. The mega-tsunami runup to an elevation of 524 m caused total forest destruction and erosion down to bedrock on a spur ridge in direct prolongation of the slide axis. A cross section of Gilbert Inlet was rebuilt at 1:675 scale in a two-dimensional physical laboratory model based on the generalized Froude similarity. A pneumatic landslide tsunami generator was used to generate a high-speed granular slide with controlled impact characteristics. State-of-the-art laser measurement techniques such as particle image velocimetry (PIV) and laser distance sensors (LDS) were applied to the decisive initial phase with landslide impact and wave generation as well as the runup on the headland. PIV provided instantaneous velocity vector fields in a large area of interest and gave insight into kinematics of wave generation and runup. The entire process of a high-speed granular landslide impact may be subdivided into two main stages: (a) Landslide impact and penetration with flow separation, cavity formation and wave generation, and (b) air cavity collapse with landslide run-out and debris detrainment causing massive phase mixing. Formation of a large air cavity — similar to an asteroid impact — in the back of the landslide is highlighted. A three-dimenional pneumatic landslide tsunami generator was designed, constructed and successfully deployed in the tsunami wave basin at OSU. The Lituya Bay landslide was reproduced in a three-dimensional physical model at 1:400 scale. The landslide surface velocities distribution was measured with PIV. The measured tsunami amplitude and runup heights serve as benchmark for analytical and numerical models.

  14. 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

  15. 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.

  16. 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.

  17. Automated optical image correlation to constrain dynamics of slow-moving landslides

    NASA Astrophysics Data System (ADS)

    Mackey, B. H.; Roering, J. J.; Lamb, M. P.

    2011-12-01

    Large, slow-moving landslides can dominate sediment flux from mountainous terrain, yet their long-term spatio-temporal behavior at the landscape scale is not well understood. Movement can be inconspicuous, episodic, persist for decades, and is challenging and time consuming to quantify using traditional methods such as stereo photogrammetry or field surveying. In the absence of large datasets documenting the movement of slow-moving landslides, we are challenged to isolate the key variables that control their movement and evolution. This knowledge gap hampers our understanding of landslide processes, landslide hazard, sediment budgets, and landscape evolution. Here we document the movement of numerous slow-moving landslides along the Eel River, northern California. These glacier-like landslides (earthflows) move seasonally (typically 1-2 m/yr), with minimal surface deformation, such that scattered shrubs can grow on the landslide surface for decades. Previous work focused on manually tracking the position of individual features (trees, rocks) on photos and LiDAR-derived digital topography to identify the extent of landslide activity. Here, we employ sub-pixel change detection software (COSI-Corr) to generate automated maps of landslide displacement by correlating successive orthorectified photos. Through creation of a detailed multi-temporal deformation field across the entire landslide surface, COSI-Corr is able to delineate zones of movement, quantify displacement, and identify domains of flow convergence and divergence. The vegetation and fine-scale landslide morphology provide excellent texture for automated comparison between successive orthorectified images, although decorrelation can occur in areas where translation between images is greater than the specified search window, or where intense ground deformation or vegetation change occurs. We automatically detected movement on dozens of active landslides (with landslide extent and displacement confirmed by

  18. Submarine landslides along the eastern Mediterranean Israeli continental slope

    NASA Astrophysics Data System (ADS)

    Reuven, Einav; Katz, Oded; Aharonov, Einat

    2013-04-01

    Numerous shallow submarine slope failures (scars and deposits) are observed in recent high resolution bathymetric grids of the continental slope off the Israeli eastern Mediterranean coast. The nature of these slope failures is currently not comprehensively understood as well as the question of whether the eastern Mediterranean continental slope is continuously or episodically unstable. We report here first steps towards understanding the present state of this submarine landslide system, which include mapping and analyzing the geology of the landslides and the hosting slopes. The continental slope extends from water depths of about 150 to more than 1000 meters with a slope of less than 5 degrees in general. Bathymetric grids with pixel resolution of 15 m till water depth of 700 m and 50 m till water depth of 1700 m were used. Analyzing the bathymetry revealed three main submarine surface features: (a) numerous shallow landslides, within the upper sequence of the post-Messenian sediments. Landslide widths range between hundreds to thousand of meters at the scar, with scar heights up to hundred meters. The toes of the landslides are not always mapable and lay up to a few kilometers down slope from the scar. Slope angles within the scars are 5 to more than15 degrees. At least two types of landslides were detected: presumably young slides with sharp scars, and presumably old slides with secondary slides and secondary drainage systems developed within the scar area; (b) a few kilometers long, north striking step-like lineaments. Step heights are up to 100 meters and the slopes are up to 20 degrees. The offset between parallel steps is less than a kilometer to a few kilometers. The steps are interpreted as surface expressions of growth faults rooted at the Messinian evaporates up to 1.5 kilometers below surface; (c) a few north striking channels were also detected with steep walls of more than 15 degrees, up to two kilometers width and a few kilometers length. The nature

  19. 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

  20. 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

  1. 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.

  2. 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

  3. Wetting characteristics of 3-dimensional nanostructured fractal surfaces

    NASA Astrophysics Data System (ADS)

    Davis, Ethan; Liu, Ying; Jiang, Lijia; Lu, Yongfeng; Ndao, Sidy

    2017-01-01

    This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

  4. 3-dimensional (3D) fabricated polymer based drug delivery systems.

    PubMed

    Moulton, Simon E; Wallace, Gordon G

    2014-11-10

    Drug delivery from 3-dimensional (3D) structures is a rapidly growing area of research. It is essential to achieve structures wherein drug stability is ensured, the drug loading capacity is appropriate and the desired controlled release profile can be attained. Attention must also be paid to the development of appropriate fabrication machinery that allows 3D drug delivery systems (DDS) to be produced in a simple, reliable and reproducible manner. The range of fabrication methods currently being used to form 3D DDSs include electrospinning (solution and melt), wet-spinning and printing (3-dimensional). The use of these techniques enables production of DDSs from the macro-scale down to the nano-scale. This article reviews progress in these fabrication techniques to form DDSs that possess desirable drug delivery kinetics for a wide range of applications.

  5. Steady Flow of Acoustically Fluidized Long Runout Landslides

    NASA Astrophysics Data System (ADS)

    Melosh, H. J.

    2001-12-01

    The high mobility exhibited by long runout landslides remains a geologic puzzle. In 1979 I proposed that the presence of strong internal vibrations could fluidize the rock debris composing such a landslide, and permit very large volumes of rock debris (more than 106 m3) to flow with a low coefficient of friction. Numerical simulations by Campbell in 1995 verified that a low friction mode of motion is theoretically possible but their time resolution was insufficient to validate my proposed mechanism. Since my initial proposal I performed laboratory studies of vibrated granular materials that support the rheology predicted by acoustic fluidization theory. I now report theoretical studies that apply this rheologic law to the steady flow of granular material down an incline of uniform slope. Although numerical solutions of the resulting highly nonlinear equations are generally necessary, a simple analytic solution is possible when the sound waves in the landslide propagate only short distances compared to the thickness of the slide mass. This solution shows that sustained flow is possible if a "regeneration parameter" equal to 1/2 Q e sin2 θ is equal to about 1. In this equation Q denotes the rate of energy absorption by inelastic processes, e is the vibrational energy generation efficiency, and θ is the (constant) slope. For plausible values of these parameters the critical slope on which steady sliding is possible is between 7 and 11 degrees, far lower than permitted by the static coefficient of friction. These slopes are similar to those observed for long runout landslides on the Earth, Venus, Mars and Io. The solution also shows that the velocity-depth profile is close to parabolic. Although a basal shear concentration has been reported for the Blackhawk landslide (which also possesses a basal layer of fine sand), more uniform shear is inferred in homogeneous slide masses. Campbell's numerical simulations also exhibit a parabolic velocity profile through the

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Landslide on Valles Marineris: morphology and flow dynamics

    NASA Astrophysics Data System (ADS)

    Sato, H.; Kurita, K.; Baratoux, D.; Pinet, P.

    2008-09-01

    Introduction: Valles Marineris is known as a place of numerous and well preserved landslides on Mars. In comparison with terrestrial landslides, martian landslides are distinctive in their size and morphology. As a consequence of the topography of the canyon, the averaged drop height of these landslides is about 6.5 km and the averaged volume is about 102~4 km3[1], which is 2~3 orders of magnitude larger than terrestrial ones, at the exception of marine landslides[2]. As for the morphology, clear levees with longitudinal lineations are typical features of martian landslides, whereas surfaces of the terrestrial mass movements are dominated by a rather chaotic topography with, in some cases, the occurrence of transverse ridges. The characteristics of the deposits should reflect the dynamics of the emplacement and the subsurface material properties. In particular, there is a longstanding debate about the relation between the long run-out length and the existence of subsurface volatiles (water ice, clathrates, ground water) [1,3,4,5,6,7]. The motivation of our research is the fact that material properties are expected to be deduced from the morphology of the deposits and the knowledge of the flow dynamics. Then, the characteristics of subsurface materials partially collapsed as mass movements could be documented as a function of time, considering the age of each landslide. In this study, we focus on the longitudinal grooves which are found on the surface of landslide deposits at Valles Marineris (Fig.1). This pattern is a typical feature in the martian landslides[3], and extremely rarely observed in the terrestrial mass movements. The origin is not well clarified, but it seems strong relation with the flow style or physical property of transported materials. With the objective to determine the condition of formation of the lineations, the geometric characteristics (volume, surface, thickness, run-out length) of lineated and non-lineated landslides are compared. Then

  11. The features of the landslide distribution and assessment of landslide susceptibility in Japan

    NASA Astrophysics Data System (ADS)

    Doshida, S.

    2013-12-01

    Many landslides occur in the place which the landslide generated in the past, or its surrounding area. The causes are considered to be formation of slipping surface, the moving mass which becomes vulnerable by deformation or destruction and geological structures in which a slipping surface is easily formed. Therefore, it is very important for prevention and mitigation of the landslide damages to create the landslide inventory map which is shown the place which the landslide generated in the past. National Research Institute for Earth Science and Disaster Prevention (NIED), Japan, have published the landslide inventory map "landslide distribution maps" for preventing and mitigating landslide disasters. The landslide distribution map have mapped the 380,000 or more landslide topographies in whole Japan by interpretation of aerial photographs. The individual landslide not less than 150 m wide is drawn in the landslide distribution map. The objects of this research are to clarify geological and geomorphological features of landslide distributions by analyzing the landslide distribution map and to make the landslide susceptibility map for the assessment of landslide in whole Japan. The landside distribution in whole Japan is not equal and there is a difference in the density. I propose the method of the wide area landslide assessment used by the features and distributions according to of geological setting. I calculate the landslide body ratio in each geological unit. The landslide body ratio is that the rate of the landslide body area in each geological unit and the whole area in each geological unit. The landslide body ratio can be considered that landslide susceptibility (occurrence probability of landslides) in each geological unit. As a result, an average of the landslide body ratio is about 5.2 % in whole Japan. The area consist of the accretionary complex based on volcanic rocks and plutonic rocks have comparatively high-risk landslide susceptibility, and the

  12. Slumgullion; Colorado’s natural landslide laboratory

    USGS Publications Warehouse

    Highland, L.M.

    1993-01-01

    The mountains of Colorado, and the Rocky Mountains in general, have one of the highest levels of landslide hazard in the nation. In a typical year, landslides hazard in the nation. In a typical year, landslides cause several fatalities and millions of dollars in damage to highways, pipelines, buildings, and forests in Colorado. To reduce such losses we need to understand why landslides occur and how they behave once they form. The Slumgullion landslide, an ideal natural laboratory, offers a unique opportunity to carefully observe and monitor the movement of a large, active landslide. In 1990, soon after the State of Colorado assigned high priority to hazard evaluation of the Slumgullion landslide, the USGS began an intensive study as part of its Landslide Hazards Reduction Program. 

  13. 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.; Margottini, Claudio; Canuti, Paolo; Sassa, Kyoji

    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.

  14. Landslide properties Controlled by the Denudation degree on Granite area in Japan

    NASA Astrophysics Data System (ADS)

    Matsuzawa, Makoto; Takahara, Teruyoshi; Kinoshita, Atsuhiko; Ishizuka, Tadanori

    2014-05-01

    In 2009, numerous shallow landslides were induced in a cretaceous granite region by heavy rainstorms in the area of the city of Hofu, Yamaguchi Prefecture, in western Japan. Fourteen people were killed by the debris flow. This area has a widely distributed plantation surface, and topography formed by denudation processes such as the 2009 landslides. The plantation surface area is known for the frequent occurrence of landslides in the past. However, the relation between the landslide properties and the degree of mountain denudation, which is important for predicting the landslide risk, has not been clarified. We examined the relation between the degree of mountain denudation and the shallow landslide properties [landslide density (number/km2), landslide form, and soil layer structure]. First, we classified the slopes based on the degree of mountain denudation and interpretation of the 2009 landslide scars, using 1-m resolution DEMs, aerial photographs, and field surveys. As a result, the slopes were classified into three types as follows: (1) lightly denuded slopes (L-slope), (2) moderately denuded slopes (M-slope), and (3) heavily denuded slopes (H-slope). The landslide numbers were 23, 54, and 21 in the L-slope, M-slope, and H-slope regions, respectively. Next, we analyzed the landslide properties using ESRI ArcGIS10. The landslide densities were 77/ km2, 115/ km2, and 41/ km2 in the L-slope, M-slope, and H-slope areas, respectively. The investigation area experienced heavy precipitation (about 250-300 mm per day). The landslide average volumes were 423 m3, 401 m3, and 173 m3 in the L-slope, M-slope, and H-slope areas, respectively. The landslide average angles were 28.5° , 33.2° , and 40.4° in the L-slope, M-slope, and H-slope areas, respectively. Finally, we surveyed the landslide form and soil layer structure using detailed field surveys. The landslide form in the L-slope and M-slope areas was that of an 'arc shape type', and in the H-slope area was that of

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Landslide hazard assessment: recent trends and techniques.

    PubMed

    Pardeshi, Sudhakar D; Autade, Sumant E; Pardeshi, Suchitra S

    2013-01-01

    Landslide hazard assessment is an important step towards landslide hazard and risk management. There are several methods of Landslide Hazard Zonation (LHZ) viz. heuristic, semi quantitative, quantitative, probabilistic and multi-criteria decision making process. However, no one method is accepted universally for effective assessment of landslide hazards. In recent years, several attempts have been made to apply different methods of LHZ and to compare results in order to find the best suited model. This paper presents the review of researches on landslide hazard mapping published in recent years. The advanced multivariate techniques are proved to be effective in spatial prediction of landslides with high degree of accuracy. Physical process based models also perform well in LHZ mapping even in the areas with poor database. Multi-criteria decision making approach also play significant role in determining relative importance of landslide causative factors in slope instability process. Remote Sensing and Geographical Information System (GIS) are powerful tools to assess landslide hazards and are being used extensively in landslide researches since last decade. Aerial photographs and high resolution satellite data are useful in detection, mapping and monitoring landslide processes. GIS based LHZ models helps not only to map and monitor landslides but also to predict future slope failures. The advancements in Geo-spatial technologies have opened the doors for detailed and accurate assessment of landslide hazards.

  2. Investigation of 3-dimensional structural morphology for enhancing light trapping with control of surface haze

    NASA Astrophysics Data System (ADS)

    Park, Hyeongsik; Shin, Myunghun; Kim, Hyeongseok; Kim, Sunbo; Le, Anh Huy Tuan; Kang, Junyoung; Kim, Yongjun; Pham, Duy Phong; Jung, Junhee; Yi, Junsin

    2017-04-01

    A comparative study of 3-dimensional textured glass morphologies with variable haze value and chemical texturing of the glass substrates was conducted to enhance light trapping in silicon (Si) thin film solar cells (TFSCs). The light trapping characteristics of periodic honeycomb structures show enhanced transmittance and haze ratio in numerical and experimental approaches. The periodic honeycomb structure of notched textures is better than a random or periodic carved structure. It has high transmittance of ∼95%, and haze ratio of ∼52.8%, and the haze property of the angular distribution function of transmittance shows wide scattering angles in the long wavelength region because of the wide spacing and aspect ratio of the texture. The numerical and experimental approaches of the 3-D texture structures in this work will be useful in developing high-performance Si TFSCs with light trapping.

  3. The Landslide Handbook - A Guide to Understanding Landslides

    USGS Publications Warehouse

    Highland, Lynn M.; Bobrowsky, Peter

    2008-01-01

    This handbook is intended to be a resource for people affected by landslides to acquire further knowledge, especially about the conditions that are unique to their neighborhoods and communities. Considerable literature and research are available concerning landslides, but unfortunately little of it is synthesized and integrated to address the geographically unique geologic and climatic conditions around the globe. Landslides occur throughout the world, under all climatic conditions and terrains, cost billions in monetary losses, and are responsible for thousands of deaths and injuries each year. Often, they cause long-term economic disruption, population displacement, and negative effects on the natural environment. Outdated land-use policies may not always reflect the best planning for use of land that is vulnerable to landslides. The reasons for poor or nonexistent land-use policies that minimize the perceived or actual danger and damage potential from geologic hazards are many and encompass the political, cultural, and financial complexities and intricacies of communities. Landslides often are characterized as local problems, but their effects and costs frequently cross local jurisdictions and may become State or Provincial or national problems. Growing populations may be limited in their geographic expansion, except to occupy unstable, steep, or remote areas. Often, stabilizing landslide-scarred areas is too costly, and some inhabitants have no other places to relocate. Fortunately, simple, 'low-tech' precautions and actions can be adopted to at least ensure an individual's immediate safety, and this handbook gives a brief overview of many of these options. We strongly suggest that, where possible, the assistance of professional engineers/geologists or those experienced in the successful mitigation of unstable slopes be consulted before actions are taken. This handbook helps homeowners, community and emergency managers, and decisionmakers to take the positive

  4. Possible worst-case tsunami scenarios around the Marmara Sea from combined earthquake and landslide sources

    NASA Astrophysics Data System (ADS)

    Latcharote, Panon; Suppasri, Anawat; Imamura, Fumihiko; Aytore, Betul; Yalciner, Ahmet Cevdet

    2016-12-01

    This study evaluates tsunami hazards in the Marmara Sea from possible worst-case tsunami scenarios that are from submarine earthquakes and landslides. In terms of fault-generated tsunamis, seismic ruptures can propagate along the North Anatolian Fault (NAF), which has produced historical tsunamis in the Marmara Sea. Based on the past studies, which consider fault-generated tsunamis and landslide-generated tsunamis individually, future scenarios are expected to generate tsunamis, and submarine landslides could be triggered by seismic motion. In addition to these past studies, numerical modeling has been applied to tsunami generation and propagation from combined earthquake and landslide sources. In this study, tsunami hazards are evaluated from both individual and combined cases of submarine earthquakes and landslides through numerical tsunami simulations with a grid size of 90 m for bathymetry and topography data for the entire Marmara Sea region and validated with historical observations from the 1509 and 1894 earthquakes. This study implements TUNAMI model with a two-layer model to conduct numerical tsunami simulations, and the numerical results show that the maximum tsunami height could reach 4.0 m along Istanbul shores for a full submarine rupture of the NAF, with a fault slip of 5.0 m in the eastern and western basins of the Marmara Sea. The maximum tsunami height for landslide-generated tsunamis from small, medium, and large of initial landslide volumes (0.15, 0.6, and 1.5 km3, respectively) could reach 3.5, 6.0, and 8.0 m, respectively, along Istanbul shores. Possible tsunamis from submarine landslides could be significantly higher than those from earthquakes, depending on the landslide volume significantly. These combined earthquake and landslide sources only result in higher tsunami amplitudes for small volumes significantly because of amplification within the same tsunami amplitude scale (3.0-4.0 m). Waveforms from all the coasts around the Marmara Sea

  5. 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.

  6. 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

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

    PubMed

    Shahabi, Himan; Hashim, Mazlan

    2015-04-22

    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.

  8. 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

  9. 3-dimensional electronic structures of CaC6

    NASA Astrophysics Data System (ADS)

    Kyung, Wonshik; Kim, Yeongkwan; Han, Garam; Leem, Choonshik; Kim, Junsung; Kim, Yeongwook; Kim, Keunsu; Rotenberg, Eli; Kim, Changyoung; Postech Collaboration; Advanced Light Source Collaboration; Yonsei University Team

    2014-03-01

    There is still remaining issues on origin of superconductivity in graphite intercalation compounds, especially CaC6 because of its relatively high transition temperature than other GICs. There are two competing theories on where the superconductivity occurs in this material; intercalant metal or charge doped graphene layer. To elucidate this issue, it is necessary to confirm existence of intercalant driven band. Therefore, we performed 3 dimensional electronic structure studies with ARPES to find out 3d dispersive intercalant band. However, we could not observe it, instead observed 3d dispersive carbon band. This support the aspect of charge doped graphene superconductivity more than intercalant driving aspect.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. Automated feature extraction for 3-dimensional point clouds

    NASA Astrophysics Data System (ADS)

    Magruder, Lori A.; Leigh, Holly W.; Soderlund, Alexander; Clymer, Bradley; Baer, Jessica; Neuenschwander, Amy L.

    2016-05-01

    Light detection and ranging (LIDAR) technology offers the capability to rapidly capture high-resolution, 3-dimensional surface data with centimeter-level accuracy for a large variety of applications. Due to the foliage-penetrating properties of LIDAR systems, these geospatial data sets can detect ground surfaces beneath trees, enabling the production of highfidelity bare earth elevation models. Precise characterization of the ground surface allows for identification of terrain and non-terrain points within the point cloud, and facilitates further discernment between natural and man-made objects based solely on structural aspects and relative neighboring parameterizations. A framework is presented here for automated extraction of natural and man-made features that does not rely on coincident ortho-imagery or point RGB attributes. The TEXAS (Terrain EXtraction And Segmentation) algorithm is used first to generate a bare earth surface from a lidar survey, which is then used to classify points as terrain or non-terrain. Further classifications are assigned at the point level by leveraging local spatial information. Similarly classed points are then clustered together into regions to identify individual features. Descriptions of the spatial attributes of each region are generated, resulting in the identification of individual tree locations, forest extents, building footprints, and 3-dimensional building shapes, among others. Results of the fully-automated feature extraction algorithm are then compared to ground truth to assess completeness and accuracy of the methodology.

  16. Landslides on Charon and not on Pluto

    NASA Astrophysics Data System (ADS)

    Beyer, Ross A.; Singer, Kelsi N.; Nimmo, Francis; Moore, Jeffrey M.; McKinnon, William B.; Schenk, Paul M.; Spencer, John R.; Weaver, Harold A.; Olkin, Catherine B.; Young, Leslie; Ennico, Kimberly; Stern, S. Alan; New Horizons Science Team

    2016-10-01

    Landslide features are observed on Charon but not on Pluto. This observation is another that reinforces the different strength regime of surface materials on the two bodies. Pluto's surface, although underlain by strong water ice, is primarily mantled with a variety of geologically weak ice species. Observations of these features indicate that they flow and move, but do so in a manner similar to glacial flow, and the strength and steepening required to precipitate a landslide simply isn't present in these materials under the pressure and temperature conditions on Pluto's surface. There are certainly areas of local mass-wasting, but no substantial landslide deposits. There are some locations on Pluto, notably along the fossae walls, and perhaps on the steeper montes surfaces that could have fostered landslides, but no landslide deposits have been observed nor are there obvious landslide alcoves that would have sourced them. The resolution of observations along the fossae may prevent identification there, and the toes of the steeper montes are embayed by geologically recent plains material which could be overlaying any landslide deposits.Charon, however, has a water-ice surface which exhibits many strength-dominated geologic features, and also exhibits landslide deposits. There are not many of these features and they are confined to the informally named Serenity Chasma, which has relatively steep, tall slopes, perfect for landslide initiation. We will discuss the physical characteristics of these landslide deposits and their context amongst other landslide features in the solar system.

  17. 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.

  18. Dynamic sensitivity analysis of long running landslide models through basis set expansion and meta-modelling

    NASA Astrophysics Data System (ADS)

    Rohmer, Jeremy

    2016-04-01

    Predicting the temporal evolution of landslides is typically supported by numerical modelling. Dynamic sensitivity analysis aims at assessing the influence of the landslide properties on the time-dependent predictions (e.g., time series of landslide displacements). Yet two major difficulties arise: 1. Global sensitivity analysis require running the landslide model a high number of times (> 1000), which may become impracticable when the landslide model has a high computation time cost (> several hours); 2. Landslide model outputs are not scalar, but function of time, i.e. they are n-dimensional vectors with n usually ranging from 100 to 1000. In this article, I explore the use of a basis set expansion, such as principal component analysis, to reduce the output dimensionality to a few components, each of them being interpreted as a dominant mode of variation in the overall structure of the temporal evolution. The computationally intensive calculation of the Sobol' indices for each of these components are then achieved through meta-modelling, i.e. by replacing the landslide model by a "costless-to-evaluate" approximation (e.g., a projection pursuit regression model). The methodology combining "basis set expansion - meta-model - Sobol' indices" is then applied to the La Frasse landslide to investigate the dynamic sensitivity analysis of the surface horizontal displacements to the slip surface properties during the pore pressure changes. I show how to extract information on the sensitivity of each main modes of temporal behaviour using a limited number (a few tens) of long running simulations. In particular, I identify the parameters, which trigger the occurrence of a turning point marking a shift between a regime of low values of landslide displacements and one of high values.

  19. 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

  20. 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.

  1. 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

  2. Simple parameter estimation for complex models — Testing evolutionary techniques on 3-dimensional biogeochemical ocean models

    NASA Astrophysics Data System (ADS)

    Mattern, Jann Paul; Edwards, Christopher A.

    2017-01-01

    Parameter estimation is an important part of numerical modeling and often required when a coupled physical-biogeochemical ocean model is first deployed. However, 3-dimensional ocean model simulations are computationally expensive and models typically contain upwards of 10 parameters suitable for estimation. Hence, manual parameter tuning can be lengthy and cumbersome. Here, we present four easy to implement and flexible parameter estimation techniques and apply them to two 3-dimensional biogeochemical models of different complexities. Based on a Monte Carlo experiment, we first develop a cost function measuring the model-observation misfit based on multiple data types. The parameter estimation techniques are then applied and yield a substantial cost reduction over ∼ 100 simulations. Based on the outcome of multiple replicate experiments, they perform on average better than random, uninformed parameter search but performance declines when more than 40 parameters are estimated together. Our results emphasize the complex cost function structure for biogeochemical parameters and highlight dependencies between different parameters as well as different cost function formulations.

  3. A probabilistic approach for assessing landslide-triggering event rainfall in Papua New Guinea, using TRMM satellite precipitation estimates

    NASA Astrophysics Data System (ADS)

    Robbins, J. C.

    2016-10-01

    Large and numerous landslides can result in widespread impacts which are felt particularly strongly in the largely subsistence-orientated communities residing in the most landslide-prone areas of Papua New Guinea (PNG). Understanding the characteristics of rainfall preceding these landslide events is essential for the development of appropriate early warning systems and forecasting models. Relationships between rainfall and landslides are frequently complex and uncertainties tend to be amplified by inconsistent and incomplete landslide catalogues and sparse rainfall data availability. To address some of these uncertainties a modified Bayesian technique has been used, in conjunction with the multiple time frames method, to produce thresholds of landslide probability associated with rainfall events of specific magnitude and duration. Satellite-derived precipitation estimates have been used to derive representative rainfall accumulations and intensities over a range of different rainfall durations (5, 10, 15, 30, 45, 60, 75 and 90 days) for rainfall events which resulted in landslides and those which did not result in landslides. Of the two parameter combinations (accumulation-duration and intensity-duration) analysed, rainfall accumulation and duration provide the best scope for identifying probabilistic thresholds for use in landslide warning and forecasting in PNG. Analysis of historical events and rainfall characteristics indicates that high accumulation (>250 mm), shorter duration (<15 days) rainfall events and long duration (>75 days), high accumulation (>1200 mm) rainfall events are more likely to lead to moderate- to high-impact landslides. This analysis has produced the first proxy probability thresholds for landslides in PNG and their application within an early warning framework has been discussed.

  4. Modelling landslide-generated tsunami: from landslide propagation to downstream flood in dam context

    NASA Astrophysics Data System (ADS)

    Franz, Martin; Podladchikov, Yury; Humair, Florian; Matasci, Battista; Jaboyedoff, Michel

    2015-04-01

    Alpine regions have a high density of dammed lakes, either natural or anthropogenic. Those are frequently surrounded by steep slopes and thus, are potentially affected by mass wasting processes. The penetration of landsliding material in the water body may lead to impulse waves that could overtop the dam and, in the worst case scenario, breach or break the latter. The possible resulting outburst flood is a serious threat for populated places, commonly concentrated downstream in the valleys. In order to assess the risk resulting from the succession of all phenomenon, a numerical model able to handle all of them is required. Although specific models of flooding simulation or wave propagation are efficient, there is currently no fully achieved model capable to integrate all the above-mentioned processes at the same time. In order to address this, we propose a new model capable to handle these difficult combinations and which is suitable for risk assessment in dam contexts. Our model is based on both the shallow water equations and viscous flow equations. The first ones are stabilised by the Lax-Friedrichs scheme and compute the wave propagation and the downstream flow, i.e. the wet state. The viscous flow equations are used for the dry state and to propagate the landslide body. The transition from one state to the other is ruled by a threshold based on the Reynolds number. First, in order to test the capacity of our model to endure critical situations, we conducted numerical sandbox tests such as Riemann problems, dam break, and landslide tsunami-related ones in 2 dimensions. In a second time, the model is applied on a real case study: the Oeschinen Lake (Switzerland). This naturally dammed lake is specifically selected since it is potentially affected by all above-mentioned phenomenon, including landsliding, wave generation, wave propagation in the water body and on the shore as well as the downstream flooding. Results show that the municipality of Kandersteg

  5. 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…

  6. 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.

  7. 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.

  8. 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

  9. A Probabilistic Approach to Transient Hydrology and Landslide Triggering

    NASA Astrophysics Data System (ADS)

    Simoni, S.; Rigon, R.; Godt, J. W.; Savage, W. Z.

    2005-12-01

    We present results from a 3D, transient coupled simulation of hillslope hydrology and slope stability for a steep alpine catchment that experienced shallow landslides during an intense period of rain. These results reproduce observed spatial and temporal distributions of rainfall-induced landslides. The distributed coupled hydrological-geotechnical model, GEOtop-SF, describes processes related to slope hydrology and slope stability. It combines a 3D numerical solution of the Richards equation and a slope-stability analysis. Hydrological processes are simulated by GEOtop which runs on a 3D grid built on detailed topography. It contains a detailed description of the interactions between topography and solar radiation (shortwave and longwave) in order to compute the energy budget and the 3D water balance. The model describes the temporal variation of the water table, of the soil moisture content and of the matric suction within the whole basin. It also simulates the transient pore-water pressure due to infiltration and redistribution processes, which is of primary importance in landslide triggering. The SF module performs the shallow stability analysis by applying a simple infinite-slope model with a probabilistic approach to account for uncertainty of the soil-strength parameters such as soil cohesion, cohesion due to vegetation and internal friction angle. Geotechnical properties are determined through field and laboratory tests. The probabilistic approach reflects the variability and the heterogeneity of the soil that greatly affects local slope stability. Results show that the probability of landsliding varies in space and time. The likelihood of landslide occurrence is greatest a few days after the peak of the precipitation at a depth of 0.8m. At this time the model computes high failure probability for the steepest and unvegetated areas. In addition, the model highlights that, for a given location, this probability increases with depth. Aerial photos of this

  10. Proposed method for hazard mapping of landslide propagation zone

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    Sustainable development of communities situated in areas with landslide potential requires a fully understanding of the mechanisms that govern the triggering of the phenomenon as well as the propagation of the sliding mass, with catastrophic consequences on the nearby inhabitants and environment. Modern analysis methods for areas affected by the movement of the soil bodies are presented in this work, as well as a new procedure to assess the landslide hazard. Classical soil mechanics offer sufficient numeric models to assess the landslide triggering zone, such as Limit Equilibrium Methods (Fellenius, Janbu, Morgenstern-Price, Bishop, Spencer etc.), blocks model or progressive mobilization models, Lagrange-based finite element method etc. The computation methods for assessing the propagation zones are quite recent and have high computational requirements, thus not being sufficiently used in practice to confirm their feasibility. The proposed procedure aims to assess not only the landslide hazard factor, but also the affected areas, by means of simple mathematical operations. The method can easily be employed in GIS software, without requiring engineering training. The result is obtained by computing the first and second derivative of the digital terrain model (slope and curvature maps). Using the curvature maps, it is shown that one can assess the areas most likely to be affected by the propagation of the sliding masses. The procedure is first applied on a simple theoretical model and then used on a representative section of a high exposure area in Romania. The method is described by comparison with Romanian legislation for risk and vulnerability assessment, which specifies that the landslide hazard is to be assessed, using an average hazard factor Km, obtained from various other factors. Following the employed example, it is observed that using the Km factor there is an inconsistent distribution of the polygonal surfaces corresponding to different landslide

  11. 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

  12. Use of landslides for paleoseismic analysis

    USGS Publications Warehouse

    Jibson, R.W.

    1996-01-01

    In many environments, landslides preserved in the geologic record can be analyzed to determine the likelihood of seismic triggering. If evidence indicates that a seismic origin is likely for a landslide or group of landslides, and if the landslides can be dated, then a paleo-earthquake can be inferred, and some of its characteristics can be estimated. Such paleoseismic landslide studies thus can help reconstruct the seismic history of a site or region. In regions that contain multiple seismic sources and in regions where surface faulting is absent, paleoseismic ground-failure studies are valuable tools in hazard and risk studies that are more concerned with shaking hazards than with interpretation of the movement histories of individual faults. Paleoseismic landslide analysis involves three steps: (1) identifying a feature as a landslide, (2) dating the landslide, and (3) showing that the landslide was triggered by earthquake shaking. This paper addresses each of these steps and discusses methods for interpreting the results of such studies by reviewing the current state of knowledge of paleoseismic landslide analysis.

  13. 3-Dimensional Analysis of Dynamic Behavior of Bearing of Nielsen Bridge

    NASA Astrophysics Data System (ADS)

    Tanimura, Shinji; Heya, Hiroyuki; Umeda, Tsutomu; Mimura, Koji; Yoshikawa, Osamu

    In 1995, the great Hanshin-Awaji earthquake caused a large amount of destruction and structural failures. One example, whose mechanism is not fully clear, is the fracture of a bridge bearing of a Nielsen type bridge that does not occur under the ordinary static or dynamic loading conditions. The fracture probably resulted from very high stress due to an unexpected dynamic mechanism. In this paper, the 3-dimensional dynamic behavior of a Nielsen type bridge was analyzed by assuming a collision between the upper and the lower parts of the bearing, which might have occurred in the great Hanshin-Awaji earthquake. The numerical results show that an impact due to a relative velocity of 5˜6m/s between the upper and the lower parts of the bearing generates a stress sufficient to cause a fracture in the upper bearing. The observed features of the actual fracture surface was also simulated fairly closely.

  14. 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.

  15. 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

  16. 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.

  17. Discovering the driving factors of landslides of the Wenchuan earthquake using remote sensing and GIS

    NASA Astrophysics Data System (ADS)

    Li, Xi; Guan, Zequn; Shen, Tiyan

    2008-12-01

    On May 12 in 2008, a Magnitude 8.0 earthquake hit Wenchuan in China, and the casualty shocked the whole world. The landslide was a frequent secondary disaster in this earthquake, so to analyze the mechanism of landslides in the disaster area is very important for post-earthquake reconstruction. The study area is located in PingWu County, which was also hit by the earthquake severely. And the data sources are ETM+ image, DEM and interpreted ALOS image. This paper considered four potential driving factors for landslides, and they are land cover, lineament, slope and drainage. The land cover was classified based on the density of vegetation, and sub-pixel analysis was employed; Density of lineament was calculated by Sobel operator and image segmentation; Slope was classified by using a threshold; Drainage was considered without numerical analysis, because it is significant and simple in study area. To find out how they influenced the landslides, conditional probability was utilized as a measurement. The result shows that areas in sparse vegetation, dense lineament and steep topography were easy to meet landslides, while drainages also induced landslides.

  18. 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.

  19. Regional landslide-hazard evaluation using landslide slopes, Western Wasatch County, Utah

    USGS Publications Warehouse

    Hylland, M.D.; Lowe, Mark

    1997-01-01

    Landsliding has historically been one of the most damaging geologic hazards in western Wasatch County, Utah. Accordingly, we mapped and analyzed landslides (slumps and debris slides) in the area to provide an empirical basis for regional landslide-hazard evaluation. The 336 landslides in the 250-sq-mi (650-km2) area involve 20 geologic units, including Mississippian- to Quaternary-aged rock and unconsolidated deposits. Landsliding in western Wasatch County is characterized by a strong correlation between geologic material and landslide-slope inclination. From a simple statistical analysis of overall slope inclinations of late Holocene landslides, we determined "critical" slope inclinations above which late Holocene landsliding has typically occurred and used these as the primary basis for defining relative landslide hazard. The critical slopes vary for individual geologic units and range from 15 to 50 percent (9??-27??). The critical slope values and landslide locations were used in conjunction with geologic and slope maps to construct qualitative landslide-susceptibility maps for use by county planners. The maps delineate areas of low, moderate, and high relative hazard and indicate where studies should be completed prior to development to evaluate site-specific slope-stability conditions. Critical slopes as determined in this study provide a consistent empirical reference that is useful for evaluating relative landslide hazard and guiding land-use-planning decisions in large, geologically complex areas.

  20. Landslide hazard analysis for Hong Kong using landslide inventory and GIS

    NASA Astrophysics Data System (ADS)

    Chau, K. T.; Sze, Y. L.; Fung, M. K.; Wong, W. Y.; Fong, E. L.; Chan, L. C. P.

    2004-05-01

    This paper presents a landslide-inventory-based and GIS-based framework for systematic landslide hazard analysis by employing historical landslide data in Hong Kong, coupling with geological, geomorphological, population, climatic, and rainfall data. Based on 1448 landslide data from 1984 to 1998, the diurnal and seasonal distributions of landslides are established and compared with the seasonal rainfall variation. The cumulative fatalities and injuries caused by landslides increase with the cumulative rainfall in Hong Kong, indicating a strong correlation between rainfall and landslide consequences. The average annual fatality and injury rates in Hong Kong caused by landslide are 11.35 and 11.63, respectively. In terms of being hit by a landslide, squatter areas and roads on Hong Kong Island are at the highest risk. A frequency-volume relation for Hong Kong Island was established, and, using this relation, it was estimated that the return period of a 26,000 m 3 landslide (the size of 1995 Shum Wan Road Landslide) is about 3.12 years. A hazard zonation map for Hong Kong Island is established by using historical data. The potential use of GIS technology to incorporate various layers of information is illustrated using Hong Kong Island as an example. Both landslide hazard and risk maps are proposed using raster calculation.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

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

    USGS Publications Warehouse

    Highland, Lynn; Sun, Ping; Edited by Margottini, Claudio; Canuti, Paolo; Sassa, Kyoji

    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.

  9. 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.

  10. 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.

  11. The Springdale, Utah, landslide: An extraordinary event

    USGS Publications Warehouse

    Jibson, R.W.; Harp, E.L.

    1996-01-01

    The most dramatic geologic effect of the M-5.7 St. George, Utah earthquake of 2 September 1992 was the triggering of the 14,000,000-m3 Springdale, Utah landslide. The roughly 10 m of landslide movement destroyed three houses, threatened several condominiums, disrupted utility lines, and temporarily closed the southwest entrance to Zion National Park. The seismic triggering of this landslide is puzzling because its distance from the earthquake epicenter, 44 km, is much greater than the farthest distance (18 km) at which similar landslides have been triggered in worldwide earthquakes of the same magnitude. Other Colorado Plateau earthquakes also have produced landslides far beyond worldwide distance limits, which suggests that regional variations in ground-shaking attenuation may require different landslide-triggering distance limits for different seismotectonic regions. Slope stability analysis and historical records of landslide movement suggest that the Springdale landslide was only slightly above limit-equilibrium conditions at the time of the earthquake. Dynamic stability analysis using Newmark's permanent-displacement method indicates coseismic landslide displacement of only 1-8 cm; this rather modest displacement probably induced enough deformation in the montmorillonitic clays along the failure surface to reduce shear strength and destabilize the slide, which continued to move for several hours after the earthquake.

  12. Quick clay and landslides of clayey soils.

    PubMed

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

    2009-10-30

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

  13. 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

  14. The first 3-dimensional assemblies of organotin-functionalized polyanions.

    PubMed

    Piedra-Garza, Luis Fernando; Reinoso, Santiago; Dickman, Michael H; Sanguineti, Michael M; Kortz, Ulrich

    2009-08-21

    Reaction of the (CH(3))(2)Sn(2+) electrophile toward trilacunary [A-alpha-XW(9)O(34)](n-) Keggin polytungstates (X = P(V), As(V), Si(IV)) with guanidinium as templating-cation resulted in the isostructural compounds Na[C(NH(2))(3)](2)[{(CH(3))(2)Sn(H(2)O)}(3)(A-alpha-PW(9)O(34))] x 9 H(2)O (1), Na[C(NH(2))(3)](2)[{(CH(3))(2)Sn(H(2)O)}(3)(A-alpha-AsW(9)O(34))] x 8 H(2)O (2) and Na(2)[C(NH(2))(3)](2)[{(CH(3))(2)Sn(H(2)O)}(3)(A-alpha-SiW(9)O(34))] x 10 H(2)O (3). Compounds 1-3 constitute the first 3-dimensional assemblies of organotin-functionalized polyanions, as well as the first example of a dimethyltin-containing tungstosilicate in the case of 3, and they show a similar chiral architecture based on tetrahedrally-arranged {(CH(3))(2)Sn}(3)(A-alpha-XW(9)O(34)) monomeric building-blocks connected via intermolecular Sn-O=W bridges regardless of the size and/or charge of the heteroatom.

  15. Mandibular reconstruction using stereolithographic 3-dimensional printing modeling technology.

    PubMed

    Cohen, Adir; Laviv, Amir; Berman, Phillip; Nashef, Rizan; Abu-Tair, Jawad

    2009-11-01

    Mandibular reconstruction can be challenging for the surgeon wishing to restore its unique geometry. Reconstruction can be achieved with titanium bone plates followed by autogenous bone grafting. Incorporation of the bone graft into the mandible provides continuity and strength required for proper esthetics and function and permitting dental implant rehabilitation at a later stage. Precious time in the operating room is invested in plate contouring to reconstruct the mandible. Rapid prototyping technologies can construct physical models from computer-aided design via 3-dimensional (3D) printers. A prefabricated 3D model is achieved, which assists in accurate contouring of plates and/or planning of bone graft harvest geometry before surgery. The 2 most commonly used rapid prototyping technologies are stereolithography and 3D printing (3DP). Three-dimensional printing is advantageous to stereolithography for better accuracy, quicker printing time, and lower cost. We present 3 clinical cases based on 3DP modeling technology. Models were fabricated before the resection of mandibular ameloblastoma and were used to prepare bridging plates before the first stage of reconstruction. In 1 case, another model was fabricated and used as a template for iliac crest bone graft in the second stage of reconstruction. The 3DP technology provided a precise, fast, and cheap mandibular reconstruction, which aids in shortened operation time (and therefore decreased exposure time to general anesthesia, decreased blood loss, and shorter wound exposure time) and easier surgical procedure.

  16. In vitro measurement of muscle volume with 3-dimensional ultrasound.

    PubMed

    Delcker, A; Walker, F; Caress, J; Hunt, C; Tegeler, C

    1999-05-01

    The aim was to test the accuracy of muscle volume measurements with a new 3-dimensional (3-D) ultrasound system, which allows a freehand scanning of the transducer with an improved quality of the ultrasound images and therefore the outlines of the muscles. Five resected cadaveric hand muscles were insonated and the muscle volumes calculated by 3-D reconstructions of the acquired 2-D ultrasound sections. Intra-reader, inter-reader and follow-up variability were calculated, as well as the volume of the muscle tissue measured by water displacement. In the results, 3-D ultrasound and water displacement measurements showed an average deviation of 10.1%; Data of 3-D ultrasound measurements were: intra-reader variability 2.8%; inter-reader variability 2.4% and follow-up variability 2.3%. 3-D measurements of muscle volume are valid and reliable. Serial sonographic measurements of muscle may be able to quantitate changes in muscle volume that occur in disease and recovery.

  17. Invasive 3-Dimensional Organotypic Neoplasia from Multiple Normal Human Epithelia

    PubMed Central

    Ridky, Todd W.; Chow, Jennifer M.; Wong, David J.; Khavari, Paul A.

    2013-01-01

    Refined cancer models are required to assess the burgeoning number of potential targets for cancer therapeutics within a rapid and clinically relevant context. Here we utilize tumor-associated genetic pathways to transform primary human epithelial cells from epidermis, oropharynx, esophagus, and cervix into genetically defined tumors within a human 3-dimensional (3-D) tissue environment incorporating cell-populated stroma and intact basement membrane. These engineered organotypic tissues recapitulated natural features of tumor progression, including epithelial invasion through basement membrane, a complex process critically required for biologic malignancy in 90% of human cancers. Invasion was rapid, and potentiated by stromal cells. Oncogenic signals in 3-D tissue, but not 2-D culture, resembled gene expression profiles from spontaneous human cancers. Screening well-characterized signaling pathway inhibitors in 3-D organotypic neoplasia helped distil a clinically faithful cancer gene signature. Multi-tissue 3-D human tissue cancer models may provide an efficient and relevant complement to current approaches to characterize cancer progression. PMID:21102459

  18. 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

  19. A shallow landslide analysis method consisting of contour line based method and slope stability model with critical slip surface

    NASA Astrophysics Data System (ADS)

    Tsutsumi, D.

    2015-12-01

    To mitigate sediment related disaster triggered by rainfall event, it is necessary to predict a landslide occurrence and subsequent debris flow behavior. Many landslide analysis method have been developed and proposed by numerous researchers for several decades. Among them, distributed slope stability models simulating temporal and spatial instability of local slopes are more essential for early warning or evacuation in area of lower part of hill-slopes. In the present study, a distributed, physically based landslide analysis method consisting of contour line-based method that subdivide a watershed area into stream tubes, and a slope stability analysis in which critical slip surface is searched to identify location and shape of the most instable slip surface in each stream tube, is developed. A target watershed area is divided into stream tubes using GIS technique, grand water flow for each stream tubes during a rainfall event is analyzed by a kinematic wave model, and slope stability for each stream tube is calculated by a simplified Janbu method searching for a critical slip surface using a dynamic programming method. Comparing to previous methods that assume infinite slope for slope stability analysis, the proposed method has advantage simulating landslides more accurately in spatially and temporally, and estimating amount of collapsed slope mass, that can be delivered to a debris flow simulation model as a input data. We applied this method to a small watershed in the Izu Oshima, Tokyo, Japan, where shallow and wide landslides triggered by heavy rainfall and subsequent debris flows attacked Oshima Town, in 2013. Figure shows the temporal and spatial change of simulated grand water level and landslides distribution. The simulated landslides are correspond to the uppermost part of actual landslide area, and the timing of the occurrence of landslides agree well with the actual landslides.

  20. Effect of forest clear-cutting on landslide occurrences: Analysis of rainfall thresholds at Mt. Ichifusa, Japan

    NASA Astrophysics Data System (ADS)

    Saito, Hitoshi; Murakami, Wataru; Daimaru, Hiromu; Oguchi, Takashi

    2017-01-01

    Vegetation cover is an important factor for rainfall-induced landslides. We analyzed the effect of forest clear-cutting on the initiation of landslides using empirical rainfall intensity-duration (I-D) thresholds at Mt. Ichifusa, Japan, which is characterized by granitic rocks. Extensive clear-cutting was conducted for the forest industry during the late 1960s in the northern part of Mt. Ichifusa. This single episode of clear-cutting caused frequent shallow landslides triggered by rainfall. We interpreted orthorectified aerial photographs from 1969, 1976, 1980, 1985, 1990, 1995, 1999, and 2005 using GIS and mapped landslides based on these photographs. We then analyzed all rainfall events of the warm seasons (Apr.-Oct.) of 1952-2011 (60 years) based on hourly rain gauge data. We used basic rainfall parameters such as mean rainfall intensity (I, mm/h) and duration (D, h) and estimated the return periods of these rainfall conditions. We investigated rainfall I-D thresholds for landslide occurrences in each period represented by the aerial photographs and assessed the relationships between landslide occurrences and topographic characteristics from 10-m DEMs. The results show that several landslides occurred after clear-cutting before 1976 but that they have occurred most frequently during the periods 1976-1980, 1980-1985, and 1990-1995. Numerous landslides occurred in these years at steeper and gentler slopes in the clear-cut area, but few landslides occurred in the non-clear-cut area. Rainfall analysis demonstrates that rainfall I-D thresholds after clear-cutting declined to half of those of the non-clear-cut area. The return periods of these rainfall I-D thresholds also declined to 1 year for short durations of < 12 h and to < 3 years for 72 h in the clear-cut area. Our findings underscore the substantial hysteresis effects between clear-cutting and landslide occurrences at Mt. Ichifusa.

  1. 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

  2. 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

  3. Towards a better understanding of a large rotational soil slide (Ludoialm Landslide, Austria)

    NASA Astrophysics Data System (ADS)

    Krenn, Julia; Mergili, Martin; Ottner, Franz; Wriessnig, Karin; Schneider-Muntau, Barbara; Zangerl, Christian

    2014-05-01

    We investigate the geological and geotechnical characteristics of the Ludoialm Landslide (Tyrol, Austria), a very slow to extremely slow clay, silt rotational slide located in the Northern Calcareous Alps. With a length of 700 m and a maximum width of 300 m the landslide involves at least 500,000 m³ of till and debris flow deposits. Given that the Ludoialm Landslide occurs in a relatively flat terrain with an average slope angle of 17°, a particular geotechnical and hydrogeological situation is assumed. This study focuses on processes and mechanisms which have triggered the soil slide. Several methods are applied to gain an integral understanding of the landslide including the analysis of historic documents and aerial views, geomorphological and geological field mapping, laboratory analysis of geotechnical parameters and clay mineralogy, numerical modelling and remote sensing. The Ludoialm Landslide dates back at least to the time of the oldest campaign of aerial imagery in this area in 1952. However it can be assumed that the initial formation of the landslide is much older. Digital photogrammetry is applied to derive a sequence of terrain models from stereo pairs of historic aerial views. These terrain models are then used to simulate the deformation history of the landslide during the last decades. In the last sixty years, the landslide area has extended notably and was reactivated twice in 1967 and 1999 as a result of intensive snow melting in spring. Detailed field mapping showed that the landslide consists of several slabs of variable activity and secondary slides at the toe. In order to improve the understanding of the geotechnical and hydrogeological characteristics of the landslide, samples for laboratory analyses were collected from the till and debris flow deposits as well as from the underlying marl. On the one hand, a mineral analysis using X-ray diffraction was performed whereas on the other hand, drained and undrained triaxial tests were conducted

  4. 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

  5. Landslide risk mitigation through integrated monitoring and modelling

    NASA Astrophysics Data System (ADS)

    Terranova, Oreste Giuseppe; Gariano, Stefano Luigi; Iovine, Giulio G. R.

    2014-05-01

    In winter 2008-09, exceptional prolonged rains triggered numerous landslides in Calabria (southern Italy). Among these, a large rock slide was triggered on 28 January 2009 in weathered metamorphic rocks at San Benedetto Ullano (CS), involving fractured and altered migmatitic gneiss and biotitic schist. A detailed geomorphological survey was carried out during the entire phase of mobilization, allowing to recognize the evolution of the phenomenon. A series of benchmarks was promptly placed in correspondence of fractures on the body and along the sides of the landslide, allowing for frequent measurements of surface movements. In addition, a network of real-time monitoring extensometers were implemented at the surface of the landslide, combined with a meteorological station. The survey site and the data of the monitoring system allowed, from the early stages of activation of the phenomenon, to implement a support system to handle the emergency. In the following months, a clear retrogressive distribution could be identified, coupled with a tendency towards the enlargement of the flanks. In early May, the first crisis ended up. After the arrest of the phenomenon, a geological-technical scheme of the slope could be drawn, also based on data collected through a set of 5 exploratory wells (equipped with 4 inclinometers and 1 piezometer). The landslide mobilized a thickness from 15 to 35 meters along the longitudinal profile. To examine the stability of the slope affected by the landslide, and to quantify the role of fluctuations of the water table in destabilizing the slope, a parametric limit equilibrium analysis was conducted. The analysis confirmed the first interpretation of the process: the first activation of the landslide was expected, in fact, in the central portion of the slope in case, in the same area, the groundwater levels are close to ground level. Between 31 January 31 and 1 February 2010, following a further period of exceptional rainfall, the network of

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 3-Dimensional shear wave elastography of breast lesions

    PubMed Central

    Chen, Ya-ling; Chang, Cai; Zeng, Wei; Wang, Fen; Chen, Jia-jian; Qu, Ning

    2016-01-01

    Abstract Color patterns of 3-dimensional (3D) shear wave elastography (SWE) is a promising method in differentiating tumoral nodules recently. This study was to evaluate the diagnostic accuracy of color patterns of 3D SWE in breast lesions, with special emphasis on coronal planes. A total of 198 consecutive women with 198 breast lesions (125 malignant and 73 benign) were included, who underwent conventional ultrasound (US), 3D B-mode, and 3D SWE before surgical excision. SWE color patterns of Views A (transverse), T (sagittal), and C (coronal) were determined. Sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC) were calculated. Distribution of SWE color patterns was significantly different between malignant and benign lesions (P = 0.001). In malignant lesions, “Stiff Rim” was significantly more frequent in View C (crater sign, 60.8%) than in View A (51.2%, P = 0.013) and View T (54.1%, P = 0.035). AUC for combination of “Crater Sign” and conventional US was significantly higher than View A (0.929 vs 0.902, P = 0.004) and View T (0.929 vs 0.907, P = 0.009), and specificity significantly increased (90.4% vs 78.1%, P = 0.013) without significant change in sensitivity (85.6% vs 88.0%, P = 0.664) as compared with conventional US. In conclusion, combination of conventional US with 3D SWE color patterns significantly increased diagnostic accuracy, with “Crater Sign” in coronal plane of the highest value. PMID:27684820

  11. 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.

  12. A new preclinical 3-dimensional agarose colony formation assay.

    PubMed

    Kajiwara, Yoshinori; Panchabhai, Sonali; Levin, Victor A

    2008-08-01

    The evaluation of new drug treatments and combination treatments for gliomas and other cancers requires a robust means to interrogate wide dose ranges and varying times of drug exposure without stain-inactivation of the cells (colonies). To this end, we developed a 3-dimensional (3D) colony formation assay that makes use of GelCount technology, a new cell colony counter for gels and soft agars. We used U251MG, SNB19, and LNZ308 glioma cell lines and MiaPaCa pancreas adenocarcinoma and SW480 colon adenocarcinoma cell lines. Colonies were grown in a two-tiered agarose that had 0.7% agarose on the bottom and 0.3% agarose on top. We then studied the effects of DFMO, carboplatin, and SAHA over a 3-log dose range and over multiple days of drug exposure. Using GelCount we approximated the area under the curve (AUC) of colony volumes as the sum of colony volumes (microm2xOD) in each plate to calculate IC50 values. Adenocarcinoma colonies were recognized by GelCount scanning at 3-4 days, while it took 6-7 days to detect glioma colonies. The growth rate of MiaPaCa and SW480 cells was rapid, with 100 colonies counted in 5-6 days; glioma cells grew more slowly, with 100 colonies counted in 9-10 days. Reliable log dose versus AUC curves were observed for all drugs studied. In conclusion, the GelCount method that we describe is more quantitative than traditional colony assays and allows precise study of drug effects with respect to both dose and time of exposure using fewer culture plates.

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. Modeling landslide mechanics in a tectonic and volcanic environment (southern Cianjur, Indonesia): A heuristic-probabilistic approach

    NASA Astrophysics Data System (ADS)

    Djamaluddin, Ridwan

    Southern Cianjur experiences numerous landslides. This study determines that stratigraphic and geologic structures control their occurrences. Sequences of rocks that have contrasting physical characteristics---such as the Lower Part of the Bentang Formation (Tmbl), the Upper Part of the Bentang Formation (Tmbu), and volcanic products (Quk)---create potential slip surfaces along their contacts. Dips in the bedding planes that are in the same direction with the slope surface (synclinal valley slope) contribute further deterioration to these unfavorable conditions. In addition, some landslides are triggered by faults. Other, smaller landslides are the result of local slope conditions, including low soil cohesion, high water content, and low internal friction angle. The above results were obtained through assessments of landslides and the potential causative factors in the framework of a slope system, as suggested by the General System Theory. This study considers lithology, soil, slope inclination, landcover, rainfall, earthquake, and faults as the components of slope systems related to landslides. The methods that evaluate the relationship between landslides and these components include Geographic Information Systems (GIS), statistical software packages, and geotechnical analyses. The results of these methods are consistent. However, a background knowledge in earth sciences also plays an important role in creating a model of the landslide mechanisms in Southern Cianjur.

  3. 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.

  4. 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

  5. National landslide susceptibility map for Germany

    NASA Astrophysics Data System (ADS)

    Glade, T.; Dikau, R.; Bell, R.

    2003-04-01

    Landslide susceptibility is generally based on historical data and field mapping, Resulting maps usually cover regions ranging between local and regional scales. However, also national scale analysis is important to delineate regions most prone to landsliding. Herein it is crucial to define the parameters, which are most important within this scale, and indeed, which can be derived from national data sets. This study aims to demonstrate a method on how to obtain national scale landslide susceptibility maps. In this study, German landslide literature was extensively reviewed. Due to the varying nature of the different sources and publications, only the information on lithology and slope angle was compiled. To include local knowledge, returned questionnaires send to experts in landslide research were evaluated and respective information summarized. For regions with no information, generalized geotechnical properties for existing lithology were applied. Additionally, a geological map at a scale of 1:1.000.000 and a nationwide digital terrain model with a resolution of 25 m x 25 m were available. The combination of slope angle and lithology was qualitatively classified in negligible, minor, moderate and high landslide susceptibility classes and applied to the data. Due to the resolution of the geology map, the 25 m resolution has been aggregated to 150 m, which seemed appropriate considering the extend of most of the landslides. Coastal landslide susceptibility has been derived from an existing data set. The map delineates areas of different landslide susceptibilities. The regions include cuestas, steep slopes in rolling midland topography and in the Alps, as well as slopes of deeply dissected rivers. Work in progress includes an evaluation of the calculated landslide susceptibility map using regional data sets. Although it is a preliminary result, this study presents the potential of such maps for planning and management purposes.

  6. 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...

  7. 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.

  8. 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

  9. Landsliding in Allegheny County, Pennsylvania

    USGS Publications Warehouse

    Briggs, Reginald Peter; Pomeroy, John S.; Davies, William E.

    1975-01-01

    Man should proceed with caution if modifications such as loading, excavation, or changes of the water regime are contemplated for slopes in Allegheny County, especially those slopes described on the map as highly sensitive to disturbance by man. Features indicative of unstable slope conditions include: cracks in buildings, yard walls, and pools; doors and windows that jam; fences and other linear features bowed out of line; tilted trees and utility poles; cracks and steplike ground features; hummocky ground; and water seeps. Geologic factors related to the landsliding process include rock types, layering, fracturing, and attitude; nature of soil cover; permeability of rocks and soils; and steepness of slope.

  10. Landslide hazard and risk assessment for Ambon city using landslide inventory and geographic information system

    NASA Astrophysics Data System (ADS)

    Souisa, Matheus; Hendrajaya, Lilik; Handayani, Gunawan

    2016-08-01

    Ambon Island is a volcanic islands arc and included in the territory of the archipelago of small islands are associated with subduction zones that have a degree of high vulnerability to natural disasters, such as erosion and landslides on the slopes of certain conditions. Landslides that occur various in the city of Ambon, usually occurs during the rainy season so that the impacts that occur not only occurs on site but also off site with amount of large sedimentation. This paper presents the application of digital image analysis techniques and tools Geographic Information Systems to describe the degree of landslide hazard and risk areas in locations Ambon City, Moluccas. The cause of the landslide is analyzed through various thematic layers attribute data for the study area. Landslide hazard zonation assessment is done by using historical data, while the landslide risk analysis is done by using the results of landslide hazard assessment and socioeconomic factors by using geospatial models. The risk assessment of landslides can be used to estimate the risk to the population, property and infrastructure. The study results in the form of a map of landslide hazard and the risk of landslides that act to support urban spatial planning based on disaster mitigation.

  11. 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

  12. Structure and characteristics of landslide input data and consequences on landslide susceptibility assessment and prediction capability

    NASA Astrophysics Data System (ADS)

    Oliveira, S. C.; Zezere, J. L.; Garcia, R. A. C.; Piedade, A.

    2009-04-01

    For the territorial planning and management it is of crucial importance the knowledge of the landslide susceptibility, in order to minimize the physical damages and economic losses associated to a certain instability scenario. Resultant mitigation measures can only be effective if we were able to predict where future landslides will occur. In order to improve the quality of data driven landslide susceptibility assessment, recent research developed worldwide as been focused on some fundamental questions: What is the quality of landslide inventories? What is the most appropriate terrain-unit to adopt? What is the most reliable statistical model? What are the best tools to validate results? In contrast, little attention has been given in the literature to the consequences on the landslide susceptibility assessment resulting from the structure and characteristics of the landslide database. Under the assumption that the conditions that led to slope instability in the past are more likely to generate new instability in the future, the statistically-based landslide susceptibility evaluation for a specific area is based on the spatial correlation between a set of independent, predisposing landslide geo-environmental factors, and the distribution of past landslides, which are considered the dependent variable. Landslides are usually included in the susceptibility models as a single point or as a polygon representing the entire unstable area. The selection of the way landslide information enter into prediction models (point vs polygon) is frequently conditioned by software constrains, and surprisingly, the effects of this choice in landslide susceptibility results has not been made. The purpose of this study is to evaluate the quality of susceptibility results obtained for rotational slides in a 12 km2 test site located at north of Lisbon, Portugal considering: (i) the structure and characteristics of landslide input data; (ii) the capacity of different landslide inventories

  13. An Integrated Landslide-Runout Model for the Assessment of Typhoon-Induced Landslide Hazard and Early Warning Practice

    NASA Astrophysics Data System (ADS)

    Chiang, S. H.; Chang, K. T.; Chen, Y. C.; Chen, C. F.

    2014-12-01

    The study proposes an integrated landslide-runout model, iLIR-w (Integrated Landslide Initiation prediction and landslide Runout simulation at Watershed level), to assess landslide hazard affected by typhoon. For rainfall-induced landslides, many landslide model have focused on the prediction of landslide locations, but few have incorporated the prediction of landslide timing and landslide runouts in one single modeling framework. iLIR-w combines an integrated landslide model for predicting shallow landslides and a watershed-scale runout simulation to simulate the coupled processes related to landslide hazard. The study developed the model in a watershed in southern Taiwan, by using landslide inventories prepared after eight historical typhoon events (2001-2008). The study then tested iLIR-w by incorporating typhoon rainfall forecasts from the Taiwan Cooperative Precipitation Ensemble Forecast Experiment (TAPEX) to practice landslide hazard early warning of 6 h, 12 h, 24 h, 48 h before the arrival of Typhoon Morakot which seriously damaged Southern Taiwan in 2009. The model performs reasonably well in the prediction of landslide locations, timing and runouts. Therefore, the model is expected to be useful for landslide hazard prevention, and can be applied to other watersheds with similar environment, assuming that reliable model parameters are available.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. An enlarging landslide scar and evolution of the surrounding forested hillslope: Results from a dendrogeomorphic and multi-temporal LiDAR DTM survey

    NASA Astrophysics Data System (ADS)

    Keck, J. W.; Hsiao, C.; Lin, B.; Wright, W. E.; Chi, S.

    2012-12-01

    Landslide sediment hazard assessments performed in Taiwan commonly rely on the area of landslide scars clearly visible in aerial photos or satellite images to gauge sediment hazard. Although studies in Taiwan have shown that erosion rates associated with an exposed landslide scar can be more than two times as high as pre-landslide levels, it has also been shown that a significant amount of sediment is derived from further retrogressive enlargement of the scar. Hillslope surface features such as tension cracks and secondary scarps located outside of the scar may be indicative of future landslide activity, however, because temporal relationships between those features and the landslide scar are unknown, confidence in future scar enlargement area estimates can be limited. The goal of this study is to investigate how a hillslope both spatially and temporally evolves around an enlarging landslide scar and how that evolution may have been related to the final area of the scar. The hillslope is the north face of a low elevation(800m to 1200m) spur located in the northern Xueshan mountains of Taiwan. Prior to formation of the landslide scar, the hillslope was defined by a forested, nearly planar surface incised by several shallow, parallel draining hollows. During a period of strong typhoons between 1997 and 2008, the landslide scar initiated at the foot of the slope and intermittently enlarged along one of the hollows until reaching the ridgeline. Presently, numerous tension cracks, debris flow channels and smaller landslide scarps cut across the hillslope on all sides of the scar. Evolution of the scar is reconstructed using aerial photo and satellite images. The location of landslide features hidden by the forest outside of the scar are surveyed in the field and an attempt is made to identify the timing of sub-canopy movement using a dendrogeomorphic survey on primarily alder and all available conifer trees. Multiple AirLIDAR DTM data sets, recorded throughout the later

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. Map showing 1983 landslides in Utah

    USGS Publications Warehouse

    Brabb, Earl E.; Wieczorek, Gerald F.; Harp, Edwin L.

    1989-01-01

    The State of Utah sustained direct damages from landslides and flooding in excess of $400 million during approximately three months in the spring of 1983.  These disastrous events were declared national disaster areas (Anderson and others, 1985).

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Lithological control on the kinematic pattern in a large clayey landslide (Avignonet, French Alps)

    NASA Astrophysics Data System (ADS)

    Bièvre, Grégory; Jongmans, Denis

    2014-05-01

    the whole landslide) and was validated by hydrogeological observations and permeability measurements. Electrical imaging of the superficial coarser layer allowed a new interpretation of the displacement field to be proposed. As already pointed out before in numerous studies, this case history illustrates the necessity of combining investigation and monitoring techniques for understanding the complexity of large landslide mechanism behaviour.

  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. Landslides nearby Boguchwała

    NASA Astrophysics Data System (ADS)

    Maj, Hubert

    2014-05-01

    The students of first class of our school have been working during this season about landslides nearby Boguchwała - where our school is located. Although landslides in Poland are most common in the Carpathian Mountains, in southern Poland, this phenomenon becomes more and more serious also in other regions. The example of them is strzyżowski powiat, nearby Boguchwała, situated about 100km on the north from the Carpathian Mountains . These landslides have occured on a large scale in the district for 2000 year. What happened in 2010 was a real cataclysm. By now, people noted about 100 active landslides in the area of the district, which caused damage to about 400 building constructions and 50 families had to leave their homes. The largest landslide is located on the western slope of the valley of Wisłok. The landslide was almost 10ha big, 326m long and 330m wide. It caused damage to houses and barns, and one of them literally fell to the ground. The ground has subsided due to the geological construction of the substrate, mountain dynamic of sculptures and frequent downfalls. It was established on the base of sandstone. To prevent the phenomenon of the proceedings should be planted different kinds of plants to stabilize the ground.

  18. Shallow landslide hazard map of Seattle, Washington

    USGS Publications Warehouse

    Harp, Edwin L.; Michael, John A.; Laprade, William T.

    2008-01-01

    Landslides, particularly debris flows, have long been a significant cause of damage and destruction to people and property in the Puget Sound region. Following the years of 1996 and 1997, the Federal Emergency Management Agency designated Seattle as a “Project Impact” city with the goal of encouraging the city to become more disaster resistant to landslides and other natural hazards. A major recommendation of the Project Impact council was that the city and the U.S. Geological Survey collaborate to produce a landslide hazard map. An exceptional data set archived by the city containing more than 100 yr of landslide data from severe storm events allowed comparison of actual landslide locations with those predicted by slope-stability modeling. We used an infinite-slope analysis, which models slope segments as rigid friction blocks, to estimate the susceptibility of slopes to debris flows, which are water-laden slurries that can form from shallow failures of soil and weathered bedrock and can travel at high velocities down steep slopes. Data used for the analysis consisted of a digital slope map derived from recent light detection and ranging (LiDAR) imagery of Seattle, recent digital geologic mapping of the city, and shear-strength test data for the geologic units found in the surrounding area. The combination of these data layers within a geographic information system (GIS) platform allowed us to create a shallow landslide hazard map for Seattle.

  19. 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

  20. 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

  1. 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.

  2. Landslides and engineering geology of the Seattle, Washington, area

    USGS Publications Warehouse

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

    2008-01-01

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

  3. 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.

  4. Control of Grasp and Manipulation by Soft Fingers with 3-Dimensional Deformation

    NASA Astrophysics Data System (ADS)

    Nakashima, Akira; Shibata, Takeshi; Hayakawa, Yoshikazu

    In this paper, we consider control of grasp and manipulation of an object in a 3-dimensional space by a 3-fingered hand robot with soft finger tips. We firstly propose a 3-dimensional deformation model of a hemispherical soft finger tip and verify its relevance by experimental data. Second, we consider the contact kinematics and derive the dynamical equations of the fingers and the object where the 3-dimensional deformation is considered. For the system, we thirdly propose a method to regulate the object and the internal force with the information of the hand, the object and the deformation. A simulation result is presented to show the effectiveness of the control method.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. Map showing landslides and areas of potential landsliding in the Salina quadrangle, Utah

    USGS Publications Warehouse

    Williams, Paul L.

    1972-01-01

    The term “landslide” is broadly defined as any “downward and outward movement of slope-forming materials composed of natural rock, soils, artificial fills, or combinations of these materials. The moving mass may proceed by any one of three principal types of movement: falling, sliding, or flossing, or by their combinations” (Varnes, 1958). Landslides and areas of potential landslides are fairly common in the rugged terrain of the Salina quadrangle. In much of the western half of the map area, relatively high rainfall, steep slopes, and flat layers of hard rock on top of very soft incompetent rock all favor landsliding, chiefly as slides and earth flows. In arid parts of the quadrangle, principally in the east half, alternating flat layers of hard and soft rocks are eroded to bare cliffs separated by benches, and rockfalls are the dominant type of landsliding. Landslides were more active in the wetter climate of the Pleistocene Epoch, which ended several thousand years ago (Smith and others, 1963, p. 52). Although landslide deposits are abundant in the Salina quadrangle, few landslide movements have been documented during historic time, partly because landslides are generally less active now than during Pleistocene times, partly because movement is commonly very slow and thus escapes notice, and partly because of the remoteness and sparse population of the area.

  10. Regional moisture balance control of landslide motion: implications for landslide forecasting in a changing climate

    USGS Publications Warehouse

    Coe, Jeffrey A.

    2012-01-01

    I correlated 12 years of annual movement of 18 points on a large, continuously moving, deep-seated landslide with a regional moisture balance index (moisture balance drought index, MBDI). I used MBDI values calculated from a combination of historical precipitation and air temperature data from A.D. 1895 to 2010, and downscaled climate projections using the Intergovernmental Panel on Climate Change A2 emissions scenario for 2011–2099. At the landslide, temperature is projected to increase ~0.5 °C/10 yr between 2011 and 2099, while precipitation decreases at a rate of ~2 mm/10 yr. Landslide movement correlated with the MBDI with integration periods of 12 and 48 months. The correlation between movement and MBDI suggests that the MBDI functions as a proxy for groundwater pore pressures and landslide mobility. I used the correlation to forecast decreasing landslide movement between 2011 and 2099, with the head of the landslide expected to stop moving in the mid-21st century. The MBDI, or a similar moisture balance index that accounts for evapotranspiration, has considerable potential as a tool for forecasting the magnitude of ongoing deep-seated landslide movement, and for assessing the onset or likelihood of regional, deep-seated landslide activity.

  11. 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

  12. Landslides from the February 4, 1976, Guatemala earthquake

    USGS Publications Warehouse

    Harp, Edwin L.; Wilson, Raymond C.; Wieczorek, Gerald F.

    1981-01-01

    The M (Richter magnitude) = 7.5 Guatemala earthquake of February 4, 1976, generated more than 10,000 landslides throughout an area of approximately 16,000 km2. These landslides caused hundreds of fatalities as well as extensive property damage. Landslides disrupted both highways and the railroad system and thus severely hindered early rescue efforts. In Guatemala City, extensive property damage and loss of life were due to ground failure beneath dwellings built too close to the edges of steeply incised canyons. We have recorded the distribution of landslides from this earthquake by mapping individual slides at a scale of 1:50,000 for most of the landslide-affected area, using high-altitude aerial photography. The highest density of landslides was in the highlands west of Guatemala City. The predominant types of earthquake-triggered landslides were rock falls and debris slides of less than 15,000 m3 volume; in addition to these smaller landslides, 11 large landslides had volumes of more than 100,000 m3. Several of these large landslides posed special hazards to people and property from lakes impounded by the landslide debris and from the ensuing floods that occurred upon breaching and rapid erosion of the debris. The regional landslide distribution was observed to depend on five major factors: (1) seismic intensity; (2) lithology: 90 percent of all landslides were within Pleistocene pumice deposits; (3) slope steepness; (4) topographic amplification of seismic ground motion; and (5) regional fractures. The presence of preearthquake landslides had no apparent effect on the landslide distribution, and landslide concentration in the Guatemala City area does not correlate with local seismic-intensity data. The landslide concentration, examined at this scale, appears to be governed mainly by lithologic differences within the pumice deposits, preexisting fractures, and amplification of ground motion by topography-all factors related to site conditions.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. Physically based prediction of earthquake induced landsliding

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    Earthquakes are an important trigger of landslides and can contribute significantly to sedimentary or organic matter fluxes. We present a new physically based expression for the prediction of total area and volume of populations of earthquake-induced landslides. This model implements essential seismic processes, linking key parameters such as ground acceleration, fault size, earthquake source depth and seismic moment. To assess the model we have compiled and normalized a database of landslide inventories for 40 earthquakes. We have found that low landscape steepness systematically leads to overprediction 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, even though the prediction of total landslide area is more difficult than that of volume because it is affected by additional parameters such as the depth and continuity of soil cover. Some outliers in terms of observed landslide intensity are likely to be associated with exceptional rock mass properties in the epicentral area. Others may be related to seismic source complexities ignored by the model. However, most cases in our catalogue seem to be relatively unaffected by these two effects despite the variety of lithologies and tectonic settings they cover. This makes the model suitable for integration into landscape evolution models, and application to the assessment of secondary hazards and risks associated with earthquakes.

  19. Population exposed to landslide risk in Italy

    NASA Astrophysics Data System (ADS)

    Trigila, Alessandro; Iadanza, Carla; Munafò, Michele; Baiocco, Fabio; Marinosci, Ines; Chiocchini, Raffaella; Mugnoli, Stefano

    2013-04-01

    Italy is one of the European countries most affected by landslides counting over 486,000 mass movements with a total area of 20,700 square kilometres equal to 6.9% of the national territory. Moreover Italy is a densely urbanized country: 8101 municipalities, about 200 inhabitants per sq. km, 16,000 km of rail network and 180,000 km of road network. Landslides caused more than 5000 fatalities in the last century and considerable damage to urban areas, transport infrastructure and facilities, environmental and cultural heritage. The aim of this work is to estimate the population exposed to landslide risk in Italy. The input data are: the Italian Landslide Inventory, the Italian Population Census data and the high-resolution Artificial surfaces-Imperviousness Layer (Geoland2). The Italian Landslide Inventory (Progetto IFFI) realised by ISPRA (Italian National Institute for Environmental Protection and Research) and the Regions and Self-governing Provinces, identifies landslides occurred in the national territory in accordance with standardized methods and using a detailed landslide mapping (1:10,000 scale). The 14th Population Census, made by ISTAT (Italian National Institute of Statistics) in 2001, contains data of resident population for the 382,534 census tracts in which Italy is divided. The pan-European high-resolution (HR) Artificial surfaces-Imperviousness Layer, realized using remote sensing data within the GMES initiative (Global Monitoring for Environment and Security) by European Commission and European Space Agency, contains the degree of imperviousness (between 0 and 100%). GIS overlay of this information layer (20 x 20 m grid) with census tracts has allowed the spatialization of population within urban settlements of each census tract. This methodology has been particularly useful in the case of rural census tracts characterized by large surface area and low population density. The methodology could be also applied to estimate the population exposed to

  20. 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.

  1. Modeling landslide recurrence in Seattle, Washington, USA

    USGS Publications Warehouse

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

    2008-01-01

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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  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. 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.

  10. Remote rainfall sensing for landslide hazard analysis

    USGS Publications Warehouse

    Wieczorek, Gerald F.; McWreath, Harry; Davenport, Clay

    2001-01-01

    Methods of assessing landslide hazards and providing warnings are becoming more advanced as remote sensing of rainfall provides more detailed temporal and spatial data on rainfall distribution. Two recent landslide disasters are examined noting the potential for using remotely sensed rainfall data for landslide hazard analysis. For the June 27, 1995, storm in Madison County, Virginia, USA, National Weather Service WSR-88D Doppler radar provided rainfall estimates based on a relation between cloud reflectivity and moisture content on a 1 sq. km. resolution every 6 minutes. Ground-based measurements of rainfall intensity and precipitation total, in addition to landslide timing and distribution, were compared with the radar-derived rainfall data. For the December 14-16, 1999, storm in Vargas State, Venezuela, infrared sensing from the GOES-8 satellite of cloud top temperatures provided the basis for NOAA/NESDIS rainfall estimates on a 16 sq. km. resolution every 30 minutes. These rainfall estimates were also compared with ground-based measurements of rainfall and landslide distribution. In both examples, the remotely sensed data either overestimated or underestimated ground-based values by up to a factor of 2. The factors that influenced the accuracy of rainfall data include spatial registration and map projection, as well as prevailing wind direction, cloud orientation, and topography.

  11. Fluidized landslides induced by extreme rainfall along basaltic caldera cliff of Mt. Aso in July 2012

    NASA Astrophysics Data System (ADS)

    Fukuoka, Hiroshi; Matsushi, Yuki; Furuya, Gen; Saito, Hitoshi

    2013-04-01

    In the end of the rainy season of 2012, a extreme rainfall affected western Japan in July and induced hundreds of fluidized landslides claiming casualties of more than 20. Measured trigger precipitation was recorded by the nearby ground-based station of the AMeDAS network (Automated Meteorological Data Acquisition System)as about 80 mm/h for consecutive 4 hours. Analysis of Radar-Raingauge Analyzed Precipitation-operated by the Japan Meteorological Agency showed landslide affected area almost coincided with the ones of heavier precipitation. Most of the landslides took place along the outer caldera rim and flank of the central cone of Mt. Aso, a basaltic active volcano. Most of the landslides slid on the boundary of strongly weathered soils, which used to be new volcanic accretion materials. Outstanding features of these landslides are: (1) This area had been affected by similar heavy rainfall decades ago, however, again a number of landslides took place in the nearby past scars; (2) Many of the soil slide bodies are shallow less than 5 meters deep and possibly immediately transformed into debris flows or mud flows and traveled long distance to reach the downslope communities; (3) Visual observation of the sources showed the high possibility that some of the slides were apparently induced by liquefaction. Similar cases were reported of past 2 landslide disasters in Japan. This strongly suggests that excessive rainfall can trigger numerous mud flows of unexpected reach. We conducted close field study at a typical soil slide - mud flow site. It originally initiated as debris or soil slide on a thin steep bedding plane of about 34 degrees consisting of coarser accretion materials. Needle penetration test showed comparatively weaker strength in the layer. It is underlain by a layer of finer materials. Such a higher permeability contrast could contribute to higher susceptibility of excess pore pressure generation. We took soil samples from the vicinity of sliding

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Landslide inventory for the Little North Santiam River Basin, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2010-01-01

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

  18. Rainfall-Triggered Landslides Bury Sri Lankan Villages

    NASA Technical Reports Server (NTRS)

    Kirschbaum, Dalia; Stanley, Thomas

    2016-01-01

    On the afternoon of May 17th, 2016, a major landslide event caused at least 92 deaths, with 109 still missing*. The site was rated highly susceptible to landslides in a new global landslide susceptibility map. GPM precipitation data suggest that both antecedent and current rainfall as well as complex topography played a role in the slope failures.

  19. 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.

  20. 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.

  1. Deterministic Approach for Estimating Critical Rainfall Threshold of Rainfall-induced Landslide in Taiwan

    NASA Astrophysics Data System (ADS)

    Chung, Ming-Chien; Tan, Chih-Hao; Chen, Mien-Min; Su, Tai-Wei

    2013-04-01

    Taiwan is an active mountain belt created by the oblique collision between the northern Luzon arc and the Asian continental margin. The inherent complexities of geological nature create numerous discontinuities through rock masses and relatively steep hillside on the island. In recent years, the increase in the frequency and intensity of extreme natural events due to global warming or climate change brought significant landslides. The causes of landslides in these slopes are attributed to a number of factors. As is well known, rainfall is one of the most significant triggering factors for landslide occurrence. In general, the rainfall infiltration results in changing the suction and the moisture of soil, raising the unit weight of soil, and reducing the shear strength of soil in the colluvium of landslide. The stability of landslide is closely related to the groundwater pressure in response to rainfall infiltration, the geological and topographical conditions, and the physical and mechanical parameters. To assess the potential susceptibility to landslide, an effective modeling of rainfall-induced landslide is essential. In this paper, a deterministic approach is adopted to estimate the critical rainfall threshold of the rainfall-induced landslide. The critical rainfall threshold is defined as the accumulated rainfall while the safety factor of the slope is equal to 1.0. First, the process of deterministic approach establishes the hydrogeological conceptual model of the slope based on a series of in-situ investigations, including geological drilling, surface geological investigation, geophysical investigation, and borehole explorations. The material strength and hydraulic properties of the model were given by the field and laboratory tests. Second, the hydraulic and mechanical parameters of the model are calibrated with the long-term monitoring data. Furthermore, a two-dimensional numerical program, GeoStudio, was employed to perform the modelling practice. Finally

  2. Detecting seasonal landslide movement within the Cascade landslide complex (Washington) using time-series SAR imagery

    USGS Publications Warehouse

    Hu, Xie; Wang, Teng; Pierson, Thomas C.; Lu, Zhong; Kim, Jin-Woo; Cecere, Thomas H.

    2016-01-01

    Detection of slow or limited landslide movement within broad areas of forested terrain has long been problematic, particularly for the Cascade landslide complex (Washington) located along the Columbia River Gorge. Although parts of the landslide complex have been found reactivated in recent years, the timing and magnitude of motion have not been systematically monitored or interpreted. Here we apply novel time-series strategies to study the spatial distribution and temporal behavior of the landslide movement between 2007 and 2011 using InSAR images from two overlapping L-band ALOS PALSAR-1 satellite tracks. Our results show that the reactivated part has moved approximately 700 mm downslope during the 4-year observation period, while other parts of the landslide complex have generally remained stable. However, we also detect about 300 mm of seasonal downslope creep in a terrain block upslope of the Cascade landslide complex—terrain previously thought to be stable. The temporal oscillation of the seasonal movement can be correlated with precipitation, implying that seasonal movement here is hydrology-driven. The seasonal movement also has a frequency similar to GPS-derived regional ground oscillations due to mass loading by stored rainfall and subsequent rebound but with much smaller magnitude, suggesting different hydrological loading effects. From the time-series amplitude information on terrain upslope of the headscarp, we also re-evaluate the incipient motion related to the 2008 Greenleaf Basin rock avalanche, not previously recognized by traditional SAR/InSAR methods. The approach used in this study can be used to identify active landslides in forested terrain, to track the seasonal movement of landslides, and to identify previously unknown landslide hazards.

  3. 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

  4. Preoperative 3-dimensional Magnetic Resonance Imaging of Uterine Myoma and Endometrium Before Myomectomy.

    PubMed

    Kim, Young Jae; Kim, Kwang Gi; Lee, Sa Ra; Lee, Seung Hyun; Kang, Byung Chul

    2017-02-01

    Uterine myomas are the most common gynecologic benign tumor affecting women of childbearing age, and myomectomy is the main surgical option to preserve the uterus and fertility. During myomectomy for women with multiple myomas, it is advisable to identify and remove as many as possible to decrease the risk of future myomectomies. With deficient preoperative imaging, gynecologists are challenged to identify the location and size of myomas and the endometrium, which, in turn, can lead to uterine rupture during future pregnancies. Current conventional 2-dimensional imaging has limitations in identifying precise locations of multiple myomas and the endometrium. In our experience, we preferred to use 3-dimensional imaging to delineate the myomas, endometrium, or blood vessels, which we were able to successfully reconstruct by using the following imaging method. To achieve 3-dimensional imaging, we matched T2 turbo spin echo images to detect uterine myomas and endometria with T1 high-resolution isotropic volume excitation-post images used to detect blood vessels by using an algorithm based on the 3-dimensional region growing method. Then, we produced images of the uterine myomas, endometria, and blood vessels using a 3-dimensional surface rendering method and successfully reconstructed selective 3-dimensional imaging for uterine myomas, endometria, and adjacent blood vessels. A Web-based survey was sent to 66 gynecologists concerning imaging techniques used before myomectomy. Twenty-eight of 36 responding gynecologists answered that the 3-dimensional image produced in the current study is preferred to conventional 2-dimensional magnetic resonance imaging in identifying precise locations of uterine myomas and endometria. The proposed 3-dimensional magnetic resonance imaging method successfully reconstructed uterine myomas, endometria, and adjacent vessels. We propose that this will be a helpful adjunct to uterine myomectomy as a preoperative imaging technique in future

  5. The Golden bypass landslide, Golden, Colorado

    USGS Publications Warehouse

    Highland, L.M.; Brown, W. M.

    1993-01-01

    Slope instability along a new highway bypass in Golden, Colorado, became a major concern in 1993. Rains and snowmelt accelerated movement of a landslide that had begun to develop before the bypass was opened to traffic in July of 1991. The downslope movement of earth materials increased significantly in 1993. During the first few months of the year, the landslide pushed onto the west shoulder of the road and crumpled the pavement beneath the south-bound lane. As we prepare this article (September, 1993), the slide continues to encroach onto the highway, posing a persistent problem despite repeated efforts to slow or stop its movement. As this article will show, permanent solutions to landslide problems of this kind are difficult to obtain. 

  6. 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.

  7. 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.

  8. Landslide hazard and forest fires - the relevance of geology for landslide type and development

    NASA Astrophysics Data System (ADS)

    Fernandez-Steeger, Tomas M.; Wiatr, Thomas; Papanikolaou, Ioannis; Reicherter, Klaus

    2010-05-01

    Current research indicates an increasing number of forest fires incidents and burned areas for Europe in the future (e.g. Moriondo et al., 2006). Besides economical and environmental impacts they can cause future "secondary" hazards like landslides, debris flows and flash floods. There are many past and current studies investigating effects of erosion and landslide phenomena like debris flows in burned areas (s. Shakesby & Doerr, 2006). The influence of the geological framework is often neglected in these studies. Furthermore, deep seated landslides and slumps are only hypothetically described (Swanson, 1981). To study the relevance of geology and to observe the processes, areas in Attica and the western Peloponnese in Greece burned by the catastrophic wildfires of 2007 and 2009 were investigated. The Tertiary Flysch units and the Neogene deposits in the Pyrgos area of the western Peloponnese are generally a landslide prone area. The slopes in the area show the typical morphological features of a landslide landscape. This is not only true for the in 2007 burned areas but also for unburned areas even in some kilometre distance. Large rotational slides with 20 m and higher main scarps interact and build up complex staircase landslide cascades. Even so vegetation indicates for the unburned areas currently a low activity. In contrary in the burned areas even 2 years after the fires many recent effects from landslides can be observed, like slope failures, cliff break ups, road failures, destroyed retention walls and cracks in houses. While the shallow landslides show a very high dynamic, also older larger landslides are developing or reactivating. As the changes in landslide activity are limited to the burned areas, it is reasonable that the changes in the hydrological conditions like Swanson (1981) predicted due to the destroyed vegetation are the main trigger mechanism for the new and reactivated landslides. An increased availability of water at the sliding plane and

  9. The 1979 Submarine Landslide-Generated Tsunami in Mururoa, French Polynesia

    NASA Astrophysics Data System (ADS)

    Poupardin, Adrien; Heinrich, Philippe; Frère, Antoine; Imbert, David; Hébert, Hélène; Flouzat, Mireille

    2017-01-01

    This paper aims at best describing the submarine landslide which induced partial submersion of the atolls of Mururoa and Fangataufa in 1979. More precisely, waves propagated along the south coast of Mururoa atoll and penetrated into its lagoon some minutes after the landslide triggering (t = 0 s), whereas a train of eight water waves reached the runway located on the north-east coast of Fangataufa (40 km south of Mururoa) between t = 7 min 30 s and t = 20 min. A numerical model based on shallow water equations is used to simulate the landslide as well as the associated tsunami. Saint-Venant equations are used to propagate the tsunami in coastal areas, whereas the offshore propagation is simulated by solving weakly nonlinear Boussinesq equations. Low- and high-resolution nested grids are used to simulate the tsunami propagation in deep sea and in shallow waters, respectively. Several scenarios have been tested to reproduce the observed water and run-up heights in the near and far fields. The best scenarios correspond to a landslide with a volume in the range (75-90 Mm3) (for a basal friction angle of 35°) and with a basal friction angle in the range (30°-40°) (for a volume of 80 Mm3). These results have been completed by a parametric study on the slide parameters.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Using Distinct-Element Method (DEM) to Investigate Tsaoling Landslide Induced by Chi-Chi Earthquake, Taiwan.

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    Large landslides occurred in the mountainous area near the epicenter on Sept. 21st, 1999, Chi-Chi earthquake in central Taiwan. These landslides were triggered by the Mw = 7.6 earthquake, which resulted in more than 2,400 people casualties and widespread damage. The 1999 Chi-Chi earthquake triggered a catastrophic Tsaloing landslide, which mobilized about 0.125 km3 of rock and soil that slid across the Chingshui River and created a 5 km long natural dam. One fifth of the landslide mass dropped into the Chingshui River, the rest crossed over Chingshui River. At least five large landslides occurred in Tsaoling area are induced by big earthquakes and downpours since 1862 to 1999. Geological investigation shows that the prevailing attitude of sedimentary formation is about N50W with a dipping angle of 12S. First we used Newmark Method to calculate the stability of slope distinct-element method to simulate Tsaoling landslide (PFC3d and PFC2d discrete element code). Because of the discrete, particle-based nature of the model, specification of material properties and boundary condition is more difficult than available continuum methods. The user may specify micro-properties that control particle-particle interaction, but have no way to directly prescribe the micro-properties of the model such as Young's modulus(E), unconfined compressive strength (UCS), Cohesion(C0), Possion's ratio(£h), coefficient of friction(£g), porosity, and the initial stress state. As a result, the process of generating an initial model with the appropriate material behavior and initial stress state is by trial-and-error, requiring the use of numerical equivalent of a biaxial rock mechanics test rig to derive the rock mechanical macro-properties. We conclude that the characteristics of Tsaoling landslide process are: (1) the rocks were bond together on sliding, and (2) the frictional coefficient was very small.

  19. 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.

  20. Earthquake triggering of landslides in highly jointed rock masses: Reconstruction of the 1783 Scilla rock avalanche (Italy)

    NASA Astrophysics Data System (ADS)

    Bozzano, Francesca; Lenti, Luca; Martino, Salvatore; Montagna, Alfredo; Paciello, Antonella

    2011-06-01

    The Scilla rock avalanche occurred on 6 February 1783 along the coast of the Calabria region (southern Italy), close to the Messina Strait. It was triggered by a mainshock of the “Terremoto delle Calabrie” seismic sequence, and it induced a tsunami wave responsible for more than 1500 casualties along the neighbouring Marina Grande beach. Based on subaerial and submarine surveys, a 5 × 106 m3 subaerial landslide was identified together with a 3 × 106 m3 submarine scar area, whereas block deposits are present in both the subaerial and submerged regions. A detailed geological reconstruction of the slope was obtained and a geomechanical characterisation of the metamorphic rocks involved in the landslide was performed. Based on this reconstruction, intense jointing conditions of the rock mass can be related to main fault zones parallel and normally oriented to the actual coastline. An engineering geology model of the landslide was devised according to an equivalent continuum approach to evaluate both stiffness and strength of the rock mass within the slope. A finite difference stress-strain numerical modelling of the Scilla landslide was performed under dynamic conditions to back-analyse the landslide trigger as well as local seismic amplifications. This modelling gave new insights into the physical interactions between seismic inputs and slopes, as it demonstrated the fundamental role played by i) the interaction between the seismic input and geological setting of unsheared rock slopes (i.e., without preexisting landslide masses), ii) cumulated strain effects due to seismic sequences, and iii) jointing conditions of the involved rock masses responsible for the seismic amplification of the landslide-prone volume, driving it toward failure conditions.

  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. The relationship among probability of failure, landslide susceptibility and rainfall

    NASA Astrophysics Data System (ADS)

    Huang, Chuen Ming; Lee, Chyi-Tyi

    2016-04-01

    Landslide hazard included spatial probability, temporal probability and size probability. Many researches evaluate spatial probability in landslide susceptibility, but it is not many in temporal probability and size probability. Because of it must own enough landslide inventories that covered entire study area and large time range. In seismology, using Poisson model to calculate temporal probability is a well-known inference. However, it required a long term and complete records to analyze. In Taiwan, the remote sensing technology made us to establish multi landslide inventories easily, but it is still lack in time series. Thus the landslide susceptibility through changed different return period triggering factor was often assumed landslide hazard. Compare with landslide inventory, collected a long tern rainfall gauge records is easy. However, landslide susceptibility is a relative spatial probability. No matter using different event or analyzing in different area, the landslide susceptibility is not equal. So which model is representative that is difficult to be decided. This study adopted histogram matching to construct basic landslide susceptibility of the region. Then the relationship between landslide susceptibility, probability of failure and rainfall in multi-event can be found out.

  3. Maps Showing Seismic Landslide Hazards in Anchorage, Alaska

    USGS Publications Warehouse

    Jibson, Randall W.; Michael, John A.

    2009-01-01

    The devastating landslides that accompanied the great 1964 Alaska earthquake showed that seismically triggered landslides are one of the greatest geologic hazards in Anchorage. Maps quantifying seismic landslide hazards are therefore important for planning, zoning, and emergency-response preparation. The accompanying maps portray seismic landslide hazards for the following conditions: (1) deep, translational landslides, which occur only during great subduction-zone earthquakes that have return periods of =~300-900 yr; (2) shallow landslides for a peak ground acceleration (PGA) of 0.69 g, which has a return period of 2,475 yr, or a 2 percent probability of exceedance in 50 yr; and (3) shallow landslides for a PGA of 0.43 g, which has a return period of 475 yr, or a 10 percent probability of exceedance in 50 yr. Deep, translational landslide hazard zones were delineated based on previous studies of such landslides, with some modifications based on field observations of locations of deep landslides. Shallow-landslide hazards were delineated using a Newmark-type displacement analysis for the two probabilistic ground motions modeled.

  4. Estimating the empirical probability of submarine landslide occurrence

    USGS Publications Warehouse

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

    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.

  5. Maps showing seismic landslide hazards in Anchorage, Alaska

    USGS Publications Warehouse

    Jibson, Randall W.

    2014-01-01

    The devastating landslides that accompanied the great 1964 Alaska earthquake showed that seismically triggered landslides are one of the greatest geologic hazards in Anchorage. Maps quantifying seismic landslide hazards are therefore important for planning, zoning, and emergency-response preparation. The accompanying maps portray seismic landslide hazards for the following conditions: (1) deep, translational landslides, which occur only during great subduction-zone earthquakes that have return periods of =300-900 yr; (2) shallow landslides for a peak ground acceleration (PGA) of 0.69 g, which has a return period of 2,475 yr, or a 2 percent probability of exceedance in 50 yr; and (3) shallow landslides for a PGA of 0.43 g, which has a return period of 475 yr, or a 10 percent probability of exceedance in 50 yr. Deep, translational landslide hazards were delineated based on previous studies of such landslides, with some modifications based on field observations of locations of deep landslides. Shallow-landslide hazards were delineated using a Newmark-type displacement analysis for the two probabilistic ground motions modeled.

  6. Landslide vulnerability criteria: a case study from Umbria, central Italy.

    PubMed

    Galli, Mirco; Guzzetti, Fausto

    2007-10-01

    Little is known about the vulnerability to landslides, despite landslides causing frequent and widespread damage to the population and the built-up environment in many areas of the world. Lack of information about vulnerability to landslides limits our ability to determine landslide risk. This paper provides information on the vulnerability of buildings and roads to landslides in Umbria, central Italy. Information on 103 landslides of the slide and slide-earth flow types that have resulted in damage to buildings and roads at 90 sites in Umbria is used to establish dependencies between the area of the landslide and the vulnerability to landslides. The dependencies obtained are applied in the hills surrounding the town of Collazzone, in central Umbria, an area for which a detailed landslide inventory map is available. By exploiting the landslide inventory and the established vulnerability curves, the geographical distribution of the vulnerability to landslides is mapped and statistics of the expected damage are calculated. Reliability and limits of the vulnerability thresholds and of the obtained vulnerability assessment are discussed.

  7. 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.

  8. 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

  9. Sensitivity of the long period seismic waves generated by a landslide on its characteristics and flow history

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    Gravitational instabilities, such as landslides, avalanches or debris flows play a key role in erosion processes and represent one of the major natural hazards in mountainous, coastal or 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 flow is still an open issue, in particular due to the lack of observations relevant to the flow dynamics. In this context, the seismic signal generated by landslides is a unique tool to get information on their dynamics. Indeed, when the landslide accelerates and decelerates on the complex topography, the spatio-temporal stress field that it applies on the ground generates seismic waves. These waves carry the memory of the flow history. 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 the rheological parameters during the flow. Because global and regional seismic networks continuously record gravitational instabilities, this new method will help gathering new data on landslide behavior. The purpose here is to identify scaling laws making it possible to extract landslide characteristics such as its volume, mass, geometry and location, from seismic observations (amplitude, duration, energy…). To address this issue, we performed a series of simulations of the landslide and generated seismic waves by varying the characteristics of the landslide such as the volume, topography, friction angle, or initial shape of the released mass and of the earth model such as seismic waves velocity, number of layers, etc. For 2D and 3D simple configurations and for real landslides, we systematically investigate how these parameters affect the generated long period seismic waves and the force at their origin, obtained by inversion of the recorded seismic signal. This study shows that the initial volume

  10. Analysing post-earthquake landslide activity using multi-temporal landslide inventories near the epicentral area of the 2008 Wenchuan earthquake

    NASA Astrophysics Data System (ADS)

    Tang, Chenxiao; Van Westen, Cees J.; Tanyas, Hakan; Jetten, Victor G.

    2016-12-01

    Large earthquakes in mountainous regions may trigger thousands of landslides, some active for years. We analysed the changes in landslide activity near the epicentre of the 2008 Wenchuan earthquake by generating five landslide inventories for different years through stereoscopic digital visual image interpretation. From May 2008 to April 2015, 660 new landslides occurred outside the co-seismic landslide areas. In April 2015, the number of active landslides had gone down to 66, less than 1 % of the co-seismic landslides, but still much higher than the pre-earthquake levels. We expect that the landslide activity will continue to decay, but may be halted if extreme rainfall events occur.

  11. 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.

  12. 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

  13. Modelling landslide hazard, soil redistribution and sediment yield of landslides on the Ugandan footslopes of Mount Elgon

    NASA Astrophysics Data System (ADS)

    Claessens, L.; Knapen, A.; Kitutu, M. G.; Poesen, J.; Deckers, J. A.

    2007-10-01

    In this study, the LAPSUS-LS landslide model, together with a digital terrain analysis of topographic attributes, is used as a spatially explicit tool to simulate recent shallow landslides in Manjiya County on the Ugandan slopes of Mount Elgon. Manjiya County is a densely populated mountainous area where landslides have been reported since the beginning of the twentieth century. To better understand the causal factors of landsliding, 81 recent landslides have been mapped and investigated. Through statistical analysis it was shown that steep concave slopes, high rainfall, soil properties and layering as well as human interference were the main factors responsible for landslides in the study area. LAPSUS-LS is used to construct a landslide hazard map, and to confirm or reject the main factors for landsliding in the area. The model is specifically designed for the analysis of shallow landslide hazard by combining a steady state hydrologic model with a deterministic infinite slope stability model. In addition, soil redistribution algorithms can be applied, whereby erosion and sedimentation by landsliding can be visualized and quantified by applying a threshold critical rainfall scenario. The model is tested in the Manjiya study area for its ability to delineate zones that are prone to shallow landsliding in general and to group the recent landslides into a specific landslide hazard category. The digital terrain analysis confirms most of the causal topographic factors for shallow landsliding in the study area. In general, shallow landslides occur at a relatively large distance from the water divide, on the transition between steep concave and more gentle convex slope positions, which points to concentration of (sub)surface flow as the main hydrological triggering mechanism. In addition, LAPSUS-LS is capable to group the recent shallow landslides in a specific landslide hazard class (critical rainfall values of 0.03-0.05 m day - 1 ). By constructing a landslide hazard

  14. 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

  15. Mapping landslide susceptibility using data-driven methods.

    PubMed

    Zêzere, J L; Pereira, S; Melo, R; Oliveira, S C; Garcia, R A C

    2017-07-01

    Most epistemic uncertainty within data-driven landslide susceptibility assessment results from errors in landslide inventories, difficulty in identifying and mapping landslide causes and decisions related with the modelling procedure. In this work we evaluate and discuss differences observed on landslide susceptibility maps resulting from: (i) the selection of the statistical method; (ii) the selection of the terrain mapping unit; and (iii) the selection of the feature type to represent landslides in the model (polygon versus point). The work is performed in a single study area (Silveira Basin - 18.2km(2) - Lisbon Region, Portugal) using a unique database of geo-environmental landslide predisposing factors and an inventory of 82 shallow translational slides. The logistic regression, the discriminant analysis and two versions of the information value were used and we conclude that multivariate statistical methods perform better when computed over heterogeneous terrain units and should be selected to assess landslide susceptibility based on slope terrain units, geo-hydrological terrain units or census terrain units. However, evidence was found that the chosen terrain mapping unit can produce greater differences on final susceptibility results than those resulting from the chosen statistical method for modelling. The landslide susceptibility should be assessed over grid cell terrain units whenever the spatial accuracy of landslide inventory is good. In addition, a single point per landslide proved to be efficient to generate accurate landslide susceptibility maps, providing the landslides are of small size, thus minimizing the possible existence of heterogeneities of predisposing factors within the landslide boundary. Although during last years the ROC curves have been preferred to evaluate the susceptibility model's performance, evidence was found that the model with the highest AUC ROC is not necessarily the best landslide susceptibility model, namely when terrain

  16. 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.

  17. 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

  18. The Use of SPOT 5 (Take 5) for Landslide Detection in Preparation for the Arrival of Sentinel-2 Satellite

    NASA Astrophysics Data System (ADS)

    Vecchiotti, Filippo; Tilch, Nils; Haberler, Alexandra

    2016-08-01

    The central part of Tyrol (Austria) was hit by a heavy rainstorm on June 7th 2015 which triggered numerous landslides and mudflows in the Sellrain valley. A series of SPOT-5 (Take 5) images from April to September 2015 for the site of Sellrain were tested. A pixel based landslide detection approach was applied in order to evaluate the potential on exploiting 5 days' time series in a similar way on the soon available SENTINEL-2 sensor. For this work, 13 scenes in total were taken into consideration, but the detection of landslide-induced change on the image data was focused on a pair of images, more precisely the one acquired on the 6th and the 11th of June 2015. This semi-automatic method exploits the geo-processing capabilities of ArcGIS software, so that his use is highly recommended in the context of disaster management.

  19. 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.

  20. 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.

  1. Timing and recurrence interval of Himalayan landslides

    NASA Astrophysics Data System (ADS)

    Pachauri, A. K.

    2009-04-01

    Himalayan landsldies have been occurring since the 55 million years ever since the Hinmlayan mountains came into being. The fact is that Himalayas are rising even today at the rate of a few cm per year as supported by the Indian Plate mtion measured by GPS. The recurrence of landsldies has not beeen documented even for well known landsldies and therefore the Border Road Organisation and Public Works departments of India are unable to realise the value of the data as the records are scanty and not formalised. There is a need to establish a data bank for landslides and debris flows as well as landslide related disasters in himalayas so that moelling for recurrence can be done. Some intersting examples of the landslides after the Chamoli earthquake are good examples of landsldies that occurred after several weeks of the earthquake at Chamoli as studied by the author. The present paper proposes the need for the analyses and a program that can be chalked out to prognasticate landslide occurrence.

  2. 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.

  3. A multi-scale approach to cost/benefit analyses of landslide prevention vs. post-event actions

    NASA Astrophysics Data System (ADS)

    Salbego, G.; Floris, M.; Busnardo, E.; Toaldo, M.

    2015-02-01

    The main aim of this paper is to test economic benefits of landslide prevention measures vs. post-event emergency actions. To this end, small and large scale analyses were performed in a training area located in the North-Eastern Italian pre-Alps that was hit by an exceptional rainfall event occurred in November 2010. At the small-scale, landslide susceptibility was initially assessed using a simple probabilistic analysis, which allowed to highlight the main landslide conditioning factors and the most hazardous areas. However, this approach revealed to be quite insufficient to reach planned goals, so a large-scale case-by-case analysis was performed: a study case was defined, according to landslide occurrence frequency and assessment of elements at risk. Numerical modeling demonstrated that remedial works carried out after the landslide - water-removal intervention such as a drainage trench - could have improved slope stability if applied before its occurrence. Then, a cost-benefit analysis was finally employed. It defined that prevention would have been economically convenient compared to a non-preventive and passive attitude, allowing a 30% saving relative to total costs. Therefore, this kind of approach could be actually used as a mean toward preventive soil protection not only within the investigated case study, but also in all those hazardous areas where preventive measures are needed.

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Multiscale/multiresolution landslides susceptibility mapping

    NASA Astrophysics Data System (ADS)

    Grozavu, Adrian; Cătălin Stanga, Iulian; Valeriu Patriche, Cristian; Toader Juravle, Doru

    2014-05-01

    Within the European strategies, landslides are considered an important threatening that requires detailed studies to identify areas where these processes could occur in the future and to design scientific and technical plans for landslide risk mitigation. In this idea, assessing and mapping the landslide susceptibility is an important preliminary step. Generally, landslide susceptibility at small scale (for large regions) can be assessed through qualitative approach (expert judgements), based on a few variables, while studies at medium and large scale requires quantitative approach (e.g. multivariate statistics), a larger set of variables and, necessarily, the landslide inventory. Obviously, the results vary more or less from a scale to another, depending on the available input data, but also on the applied methodology. Since it is almost impossible to have a complete landslide inventory on large regions (e.g. at continental level), it is very important to verify the compatibility and the validity of results obtained at different scales, identifying the differences and fixing the inherent errors. This paper aims at assessing and mapping the landslide susceptibility at regional level through a multiscale-multiresolution approach from small scale and low resolution to large scale and high resolution of data and results, comparing the compatibility of results. While the first ones could be used for studies at european and national level, the later ones allows results validation, including through fields surveys. The test area, namely the Barlad Plateau (more than 9000 sq.km) is located in Eastern Romania, covering a region where both the natural environment and the human factor create a causal context that favor these processes. The landslide predictors were initially derived from various databases available at pan-european level and progressively completed and/or enhanced together with scale and the resolution: the topography (from SRTM at 90 meters to digital

  9. 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.

  10. 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.

  11. 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

  12. Orographic Precipitation Changes and Shallow Landslide-Derived Sediment in Steep Landscapes

    NASA Astrophysics Data System (ADS)

    Bellugi, D. G.; O'Gorman, P. A.; Perron, J. T.; Milledge, D.

    2014-12-01

    -resolution topographic data and soil parameters have been well constrained. We perform numerical experiments under a range of orographic rainfall scenarios to quantify the impact of changes in extreme precipitation on landslide-derived sediment volume on steep slopes, and we compare this behavior with the historical observations available at the site.

  13. Multi-Dimensional Shallow Landslide Stability Analysis Suitable for Application at the Watershed Scale

    NASA Astrophysics Data System (ADS)

    Milledge, D.; Bellugi, D.; McKean, J. A.; Dietrich, W.

    2012-12-01

    The infinite slope model is the basis for almost all watershed scale slope stability models. However, it assumes that a potential landslide is infinitely long and wide. As a result, it cannot represent resistance at the margins of a potential landslide (e.g. from lateral roots), and is unable to predict the size of a potential landslide. Existing three-dimensional models generally require computationally expensive numerical solutions and have previously been applied only at the hillslope scale. Here we derive an alternative analytical treatment that accounts for lateral resistance by representing the forces acting on each margin of an unstable block. We apply 'at rest' earth pressure on the lateral sides, and 'active' and 'passive' pressure using a log-spiral method on the upslope and downslope margins. We represent root reinforcement on each margin assuming that root cohesion is an exponential function of soil depth. We benchmark this treatment against other more complete approaches (Finite Element (FE) and closed form solutions) and find that our model: 1) converges on the infinite slope predictions as length / depth and width / depth ratios become large; 2) agrees with the predictions from state-of-the-art FE models to within +/- 30% error, for the specific cases in which these can be applied. We then test our model's ability to predict failure of an actual (mapped) landslide where the relevant parameters are relatively well constrained. We find that our model predicts failure at the observed location with a nearly identical shape and predicts that larger or smaller shapes conformal to the observed shape are indeed more stable. Finally, we perform a sensitivity analysis using our model to show that lateral reinforcement sets a minimum landslide size, while the additional strength at the downslope boundary means that the optimum shape for a given size is longer in a downslope direction. However, reinforcement effects cannot fully explain the size or shape

  14. 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

  15. 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

  16. Landslides in the western Columbia Gorge, Skamania County, Washington

    USGS Publications Warehouse

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

    2016-11-04

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

  17. 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.

  18. Probabilistic modelling of rainfall induced landslide hazard assessment

    NASA Astrophysics Data System (ADS)

    Kawagoe, S.; Kazama, S.; Sarukkalige, P. R.

    2010-06-01

    To evaluate the frequency and distribution of landslides hazards over Japan, this study uses a probabilistic model based on multiple logistic regression analysis. Study particular concerns several important physical parameters such as hydraulic parameters, geographical parameters and the geological parameters which are considered to be influential in the occurrence of landslides. Sensitivity analysis confirmed that hydrological parameter (hydraulic gradient) is the most influential factor in the occurrence of landslides. Therefore, the hydraulic gradient is used as the main hydraulic parameter; dynamic factor which includes the effect of heavy rainfall and their return period. Using the constructed spatial data-sets, a multiple logistic regression model is applied and landslide hazard probability maps are produced showing the spatial-temporal distribution of landslide hazard probability over Japan. To represent the landslide hazard in different temporal scales, extreme precipitation in 5 years, 30 years, and 100 years return periods are used for the evaluation. The results show that the highest landslide hazard probability exists in the mountain ranges on the western side of Japan (Japan Sea side), including the Hida and Kiso, Iide and the Asahi mountainous range, the south side of Chugoku mountainous range, the south side of Kyusu mountainous and the Dewa mountainous range and the Hokuriku region. The developed landslide hazard probability maps in this study will assist authorities, policy makers and decision makers, who are responsible for infrastructural planning and development, as they can identify landslide-susceptible areas and thus decrease landslide damage through proper preparation.

  19. Rainfall-induced landslide cataloging for hazard assessment

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    Rainfall-triggered landslide hazards only represent a portion of the total fatalities associated with hydrometerological disasters; however, the economic losses and casualties caused by these hazards are greater than generally acknowledged and result in higher annual property losses than any other natural disaster. Most of the victims of landslide disasters occur in the developing world, where increased building on unstable hillslopes and poor or nonexistent mitigation activities escalate disaster risk. This research explores two landslide inventories at the global and regional scales and examines their potential applicability and validation capabilities for landslide hazard and risk assessment. The global analysis develops a methodology for compiling rainfall-triggered landslide events, drawing upon news reports, scholarly articles and other hazard databases to develop catalog at the global scale. The events cataloged in the inventory include information on the nominal and geographic location, date, affected population, information source, and a qualitative measure of the landslide event’s size and location accuracy. This global inventory differs from other landslide catalogs by providing a publicly available database of information on rainfall-triggered landslide events globally, which can be compared to other sources. The global catalog is used to evaluate preliminary landslide forecasting work as well as to assess landslide distribution and frequency worldwide. This research presents a discussion on the scientific and socio-economic implications of such a database and its utility in evaluating natural and anthropogenic triggers to hydrometeorological hazards in a changing world.

  20. 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 there…

  1. 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.

  2. Landslide inventory maps: New tools for an old problem

    NASA Astrophysics Data System (ADS)

    Guzzetti, Fausto; Mondini, Alessandro Cesare; Cardinali, Mauro; Fiorucci, Federica; Santangelo, Michele; Chang, Kang-Tsung

    2012-04-01

    Landslides are present in all continents, and play an important role in the evolution of landscapes. They also represent a serious hazard in many areas of the world. Despite their importance, we estimate that landslide maps cover less than 1% of the slopes in the landmasses, and systematic information on the type, abundance, and distribution of landslides is lacking. Preparing landslide maps is important to document the extent of landslide phenomena in a region, to investigate the distribution, types, pattern, recurrence and statistics of slope failures, to determine landslide susceptibility, hazard, vulnerability and risk, and to study the evolution of landscapes dominated by mass-wasting processes. Conventional methods for the production of landslide maps rely chiefly on the visual interpretation of stereoscopic aerial photography, aided by field surveys. These methods are time consuming and resource intensive. New and emerging techniques based on satellite, airborne, and terrestrial remote sensing technologies, promise to facilitate the production of landslide maps, reducing the time and resources required for their compilation and systematic update. In this work, we first outline the principles for landslide mapping, and we review the conventional methods for the preparation of landslide maps, including geomorphological, event, seasonal, and multi-temporal inventories. Next, we examine recent and new technologies for landslide mapping, considering (i) the exploitation of very-high resolution digital elevation models to analyze surface morphology, (ii) the visual interpretation and semi-automatic analysis of different types of satellite images, including panchromatic, multispectral, and synthetic aperture radar images, and (iii) tools that facilitate landslide field mapping. Next, we discuss the advantages and the limitations of the new remote sensing data and technology for the production of geomorphological, event, seasonal, and multi-temporal inventory maps

  3. Oxidation of sulfides and rapid weathering in recent landslides

    NASA Astrophysics Data System (ADS)

    Emberson, Robert; Hovius, Niels; Galy, Albert; Marc, Odin

    2016-09-01

    Linking together the processes of rapid physical erosion and the resultant chemical dissolution of rock is a crucial step in building an overall deterministic understanding of weathering in mountain belts. Landslides, which are the most volumetrically important geomorphic process at these high rates of erosion, can generate extremely high rates of very localised weathering. To elucidate how this process works we have taken advantage of uniquely intense landsliding, resulting from Typhoon Morakot, in the T'aimali River and surrounds in southern Taiwan. Combining detailed analysis of landslide seepage chemistry with estimates of catchment-by-catchment landslide volumes, we demonstrate that in this setting the primary role of landslides is to introduce fresh, highly labile mineral phases into the surface weathering environment. There, rapid weathering is driven by the oxidation of pyrite and the resultant sulfuric-acid-driven dissolution of primarily carbonate rock. The total dissolved load correlates well with dissolved sulfate - the chief product of this style of weathering - in both landslides and streams draining the area (R2 = 0.841 and 0.929 respectively; p < 0.001 in both cases), with solute chemistry in seepage from landslides and catchments affected by significant landsliding governed by the same weathering reactions. The predominance of coupled carbonate-sulfuric-acid-driven weathering is the key difference between these sites and previously studied landslides in New Zealand (Emberson et al., 2016), but in both settings increasing volumes of landslides drive greater overall solute concentrations in streams. Bedrock landslides, by excavating deep below saprolite-rock interfaces, create conditions for weathering in which all mineral phases in a lithology are initially unweathered within landslide deposits. As a result, the most labile phases dominate the weathering immediately after mobilisation and during a transient period of depletion. This mode of

  4. 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.

  5. 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 rep