bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrological parameter estimation for ungauged basin based on satellite altimeter data and discharge modeling. A simulation for the Caqueta River (Amazonian Basin, Colombia)
Authors: Leon J. G. , Seyler F. , Calmant S. , Bonnet M.-P. , Cauhopé M. 
Published: April 2010

Abstract. The main objective of this paper is to review the usefulness of altimetric data in ungauged or very poorly monitored basin. It is shown that altimetric measurements can be combined with a single in-situ gauge to derive a reliable stage-discharge relationship upstream from the gauge. The Caqueta River in the Colombian Amazon Basin was selected to simulate a poorly monitored basin. Thus it was possible to derive the stage-discharge relationship for 13 "virtual gauge stations'' defined at river crossing with radar altimetric ground tracks. Stage measurements are derived from altimetric data following the methodology developed by Leon et al. (2006). Discharge is modeled using PROGUM – a flow routing model based on the Muskingum Cunge (M-C) approach considering a diffusion-cum-dynamic wave propagation (Leon et al., 2006) using a single gauge located downstream from the basin under study. Rating curve parameters at virtual stations are estimated by fitting with a power law the temporal series of water surface altitude derived from satellite measurements and the modelled discharges. The methodology allows the ellipsoidal height of effective zero flow to be estimated. This parameter is a good proxy of the mean water depth from which the bottom slope of the reaches can be computed. Validation has been conducted by comparing the results with stages and discharges measured at five other gauges available on the Caqueta basin. Outflow errors range from 10% to 20% between the upper basin and the lower basin, respectively. Mean absolute differences less than 1.10 m between estimated equivalent water depth and measured water depth indicates the reliability of the proposed method. Finally, a 1.2×10−4 mm−1 mean bottom slope has been obtained for the 730 km long reach of the Caqueta main stream considered.
The EU CADZIE database for extreme and deflected snow avalanches
Authors: Domaas U. , Harbitz C. B. , Bakkehøi H. 
Published: April 2010

Abstract. The EU programme CADZIE (Catastrophic Avalanches: Defence Structures and Zoning in Europe), was established after the catastrophic 1999 avalanche winter in Europe. The overall objective of the programme is improved snow avalanche risk management by: (1) improved avalanche hazard zoning by computational models; and (2) improved understanding of the interaction between defence structures and avalanches. One contribution to meet the objectives is a database of well-documented extreme or deflected avalanche events in the six countries of the partners of the programme. The database contains observational, topographical and meteorological snow avalanche data with reliability, as well as references, copyrights, etc., all in a convenient framework based on common formats. The structure, contents, and potential use of the database are described. Example calculations of extreme and deflected events made by the NGI user interface "SKRED", for practical use of avalanche computational models, present applications of the database. Finally, further development of the database and of the computational models to meet the future needs in avalanche hazard zoning is proposed.
Co-postseismic hydrogeochemical anomalies in a volcanic environment
Authors: Biagi P. F. , Molchanov O. , Piccolo R. , Minafra A. , Ermini A. , Capozzi V. , Khatkevich Y. M. , Gordeev E. I. 
Published: April 2010

Abstract. For many years flow-rate, temperature, ions and gases content data have been collected from a natural spring located in the Koryakskiy volcano area (Kamchatka, Russia). We have investigated the correlations between the hydrogeochemical data and the areal seismicity represented by the ks values (ks is a function of magnitude and hypocentral distance) of the earthquakes. At first we smoothed the raw hydrogeochemical data using a semi-triangle weight function. Then we compared the trends of each smoothed hydrogeochemical parameter with the ks trend using a running cross-correlation function with a maximum lag of ± 30 days and the main result was that, sometimes, we found 0.7–0.4 cross-correlation coefficients with no lag for flow rate and with + (10 – 15) days lags for some ion and gas contents. The correlation is positive, i.e. flow rate and ion and gas contents increase when ks increases. This phenomenology could be explained by an underground water pumping produced by some earthquake. We advance the hypothesis that this pumping could be the response of the viscoelastic underground medium of the Koryakskiy volcano to seismic waves. So, sometimes, the supply of elastic energy of the earthquakes may provide the trigger to a catastrophic nucleation of bubbles of this material producing a new melt with a lower density which will tend to expand and cause a pressure increase. This pressure produces a more intensive circulation of underground water and an anomalous increase of the flow rate and subsequently anomalous increases in groundwater ions and gases content.
Slope instability in the Bastardo Basin (Umbria, Central Italy) – The landslide of Barattano
Authors: Cencetti C. , Conversini P. 
Published: April 2010

Abstract. The Bastardo Basin is one of the classics Apenninic intermontane basins of central Italy. They are en-closed tectonic basins (graben and semigraben) with high anthropization, but with high vulnerability, too (seismic, hydrogeological and geomorphological). The paper concerns some aspects about slope instability in the Bastardo Basin as part of a wider research, which aims to actually define the characteristics of the liability to landslides of the Apenninic intermontane basins. In particular lithological, stratigraphical and hydrogeological conditions are analysed under which a landslide near village of Barattano has developed. This mass movement, at different times, produced partial or total occlusion of the torrent Puglia. Here geognostic investigations together with laboratory tests and subsequent monitoring of landslide area were carried out. A back analysis, based on limit equilibrium solutions for the factor of safety of the slope, provided the residual strenght properties of the soil mass along the sliding surface. The landslide of Barattano is representative of a very frequent situation (in terms of type, factors and causes of the movement, possible development of the movement) not only within Bastardo Basin, but in general within Apenninic intermontane basins, too. The study of landslide and the design of appropriate remedial measures are of great importance in terms of prevention and mitigation of geologic-hydraulic risk in Apenninic intermontane basins.
Hazard assessment of debris flows for Leung King Estateof Hong Kong by incorporating GIS with numericalsimulations
Authors: Chau K. T. , Lo K. H. 
Published: April 2010

Abstract. As over seventy percent of the land of Hong Kong is mountainous, rainfall-induced debris flows are not uncommon in Hong Kong. The objective of this study is to incorporate numerical simulations of debris flows with GIS to identify potential debris flow hazard areas. To illustrate this approach, the proposed methodology is applied to Leung King Estate in Tuen Mun. A Digital Elevation Model (DEM) of the terrain and the potential debris-flow sources were generated by using GIS to provide the required terrain and flow source data for the numerical simulations. A theoretical model by Takahashi et al. (1992) improved by incorporating a new erosion initiation criterion was used for simulating the runout distances of debris flows. The well-documented 1990 Tsing Shan debris flow, which occurred not too far from Leung King Estate, was used to calibrate most of the flow parameters needed for computer simulations. Based on the simulation results, a potential hazard zone was identified and presented by using GIS. Our proposed hazard map was thus determined by flow dynamics and a deposition mechanism through computer simulations without using any so- called expert opinions, which are bounded to be subjective and biased.
Integration of spatial and temporal data for the definition of different landslide hazard scenarios in the area north of Lisbon (Portugal)
Authors: Zêzere J. L. , Reis E. , Garcia R. , Oliveira S. , Rodrigues M. L. , Vieira G. , Ferreira A. B. 
Published: April 2010

Abstract. A general methodology for the probabilistic evaluation of landslide hazard is applied, taking in account both the landslide susceptibility and the instability triggering factors, mainly rainfall. The method is applied in the Fanhões-Trancão test site (north of Lisbon, Portugal) where 100 shallow translational slides were mapped and integrated into a GIS database. For the landslide susceptibility assessment it is assumed that future landslides can be predicted by statistical relationships between past landslides and the spatial data set of the predisposing factors (slope angle, slope aspect, transversal slope profile, lithology, superficial deposits, geomorphology, and land use). Susceptibility is evaluated using algorithms based on statistical/probabilistic analysis (Bayesian model) over unique-condition terrain units in a raster basis. The landslide susceptibility map is prepared by sorting all pixels according to the pixel susceptibility value in descending order. In order to validate the results of the susceptibility ana- lysis, the landslide data set is divided in two parts, using a temporal criterion. The first subset is used for obtaining a prediction image and the second subset is compared with the prediction results for validation. The obtained prediction-rate curve is used for the quantitative interpretation of the initial susceptibility map. Landslides in the study area are triggered by rainfall. The integration of triggering information in hazard assessment includes (i) the definition of thresholds of rainfall (quantity-duration) responsible for past landslide events; (ii) the calculation of the relevant return periods; (iii) the assumption that the same rainfall patterns (quantity/duration) which produced slope instability in the past will produce the same effects in the future (i.e. same types of landslides and same total affected area). The landslide hazard is present as the probability of each pixel to be affected by a slope movement, and results from the coupling between the susceptibility map, the prediction-rate curve, and the return periods of critical rainfall events, on a scenario basis. Using this methodology, different hazard scenarios were assessed, corresponding to different rain paths with different return periods.
Probabilistic high-resolution forecast of heavy precipitation over Central Europe
Authors: Marsigli C. , Montani A. , Nerozzi F. , Paccagnella T. 
Published: April 2010

Abstract. The limited-area ensemble prediction system COSMO-LEPS has been running operationally at ECMWF since November 2002. Five runs of the non-hydrostatic limited-area model Lokal Modell (LM) are available every day, nested on five selected members of three consecutive 12-h lagged ECMWF global ensembles. The limited-area ensemble forecasts range up to 120h and LM-based probabilistic products are disseminated to several national weather services. COSMO-LEPS has been constructed in order to have a probabilistic system with high resolution, focussing the attention on extreme events in regions with complex orography. In this paper, the performance of COSMO-LEPS for a heavy precipitation event that affected Central Europe in August 2002 has been examined. At the 4-day forecast range, the probability maps indicate the possibility of the overcoming of high precipitation thresholds (up to 150mm/24h) over the region actually affected by the flood. Furthermore, one out of the five ensemble members predicts 4 days ahead a precipitation structure very similar to the observed one.
Analysis of an intense bora event in the Adriatic area
Authors: Cesini D. , Morelli S. , Parmiggiani F. 
Published: April 2010

Abstract. Numerical simulations of a bora event, recently occurred in the Adriatic area, are presented. Two reference runs at different horizontal resolution (about 20km and 8km) describe the case. Initial conditions for the atmospheric model integration are obtained from ECMWF analyses. Satellite data are used for comparisons. A further run at horizontal resolution of 8km, using initial satellite sea surface temperatures, is performed to evaluate their impact on the low level wind over the Adriatic Sea. All the simulations are carried out with 50 layers in the vertical. Numerous aspects of the simulations are found to be in agreement with the understanding as well as the observational knowledge of bora distinctive characteristics. Satellite data and model results indicate that a more realistic simulation of the bora wind over the sea is achieved using the model with 8km horizontal resolution and that the low level wind in this case is sensitive, though weakly, to the difference between the used sea surface temperature fields. Simulation results also show that both wind intensity and the area around wind peaks tend to increase when relatively higher sea surface temperatures are used.
Anomalies of LF signal during seismic activity in November–December 2004
Authors: Rozhnoi A. A. , Solovieva M. S. , Molchanov O. A. , Hayakawa M. , Maekawa S. , Biagi P. F. 
Published: April 2010

Abstract. A signal transmitted by Japan Time Standard LF station (40 kHz, Fukushima prefecture) and recorded in Petropavlovsk-Kamchatski (Russia) is analyzed during a time interval from 1 July 2004 till 24 January 2005. This interval is characterized by quiet seismic conditions up to the beginning of November, but rather strong seismic activity occurs in November and December not far from Hokkaido (Japan) and in the region of northern Kuril Islands. There were three series of earthquakes with M=5.6–7.1 in a zone of sensitivity of our wave path during two months. Nighttime "bay-like" phase and amplitude anomalies of the LF signal are observed several days before and during every series of earthquakes. During the whole period of seismic activity a significant shift in terminator times is also evident. The spectrum of LF seismo-induced anomalies shows a clear increase for the period of about 25 min.
Estimation of the regional stock of residential buildings as a basis for a comparative risk assessment in Germany
Authors: Kleist L. , Thieken A. H. , Köhler P. , Müller M. , Seifert I. , Borst D. , Werner U. 
Published: April 2010

Abstract. One important prerequisite for a comparable quantitative risk assessment for different types of hazards (e.g., earthquakes, windstorms and floods) is the use of a common database about and financial appraisal of the assets at risk. For damage assessments it is necessary to represent the values at risk on a regional disaggregated scale and to intersect them with hazard scenarios. This paper presents a methodology and results of a financial appraisal of residential buildings for all communities in Germany. The calculated values are defined as replacement values for the reference year 2000. The resulting average replacement costs for residential buildings per inhabitant amount to EUR 46 600, with considerable differences between communities. The inventory can be used for the calculations of direct losses from various natural disasters within the project "Risk Map Germany''.
Evolving towards a critical point: A possible electromagnetic way in which the critical regime is reached as the rupture approaches
Authors: Kapiris P. G. , Eftaxias K. A. , Nomikos K. D. , Polygiannakis J. , Dologlou E. , Balasis G. T. , Bogris N. G. , Peratzakis A. S. , Hadjicontis V. E. 
Published: April 2010

Abstract. In analogy to the study of critical phase transitions in statistical physics, it has been argued recently that the fracture of heterogeneous materials could be viewed as a critical phenomenon, either at laboratory or at geophysical scales. If the picture of the development of the fracture is correct one may guess that the precursors may reveal the critical approach of the main-shock. When a heterogeneous material is stretched, its evolution towards breaking is characterized by the appearance of microcracks before the final break-up. Microcracks produce both acoustic and electromagnetic(EM) emission in the frequency range from VLF to VHF. The microcracks and the associated acoustic and EM activities constitute the so-called precursors of general fracture. These precursors are detectable not only at laboratory but also at geophysical scales. VLF and VHF acoustic and EM emissions have been reported resulting from volcanic and seismic activities in various geologically distinct regions of the world. In the present work we attempt to establish the hypothesis that the evolution of the Earth's crust towards the critical point takes place not only in a mechanical but also in an electromagnetic sense. In other words, we focus on the possible electromagnetic criticality, which is reached while the catastrophic rupture in the Earth's crust approaches. Our main tool is the monitoring of micro-fractures that occur before the final breakup, by recording their radio-electromagnetic emissions. We show that the spectral power law analysis of the electromagnetic precursors reveals distinguishing signatures of underlying critical dynamics, such as: (i) the emergence of memory effects; (ii) the decrease with time of the anti-persistence behaviour; (iii) the presence of persistence properties in the tail of the sequence of the precursors; and (iv) the acceleration of the precursory electro-magnetic energy release. Moreover, the statistical analysis of the amplitudes of the electromagnetic fluctuations reveals the breaking of the symmetry as the theory predicts. Finally, we try to answer the question: how universal the observed electromagnetic critical behaviour of the failing system is?
The nonlinear coupling of electromagnetic ion cyclotron and lower hybrid waves in the ring current region: the magnetic storm 1-7May 1998
Authors: Khazanov G. V. , Krivorutsky E. N. , Gamayunov K. V. , Avanov L. A. 
Published: April 2010

Abstract. The excitation of lower hybrid waves (LHWs) is a widely discussed mechanism of interaction between plasma species in space, and is one of the unresolved questions of magnetospheric multi-ion plasmas. In this paper we present the morphology, dynamics, and level of LHW activity generated by electromagnetic ion cyclotron (EMIC) waves during the 2-7 May 1998 storm period on the global scale. The LHWs were calculated based on a newly developed self-consistent model (Khazanov et. al., 2002) that couples the system of two kinetic equations: one equation describes the ring current (RC) ion dynamic, and another equation describes the evolution of EMIC waves. It is found that the LHWs are excited by helium ions due to their mass dependent drift in the electric field of EMIC waves. The level of LHW activity is calculated assuming that the induced scattering process is the main saturation mechanism for these waves. The calculated LHWs electric fields are consistent with the observational data.
A simplified model of the Martian atmosphere - Part 2: a POD-Galerkin analysis
Authors: Whitehouse S. G. , Lewis S. R. , Moroz I. M. , Read P. L. 
Published: April 2010

Abstract. In Part I of this study Whitehouse et al. (2005) performed a diagnostic analysis of a simplied model of the Martian atmosphere, in which topography was absent and in which heating was modelled as Newtonian relaxation towards a zonally symmetric equilibrium temperature field. There we derived a reduced-order approximation to the vertical and the horizonal structure of the baroclinically unstable Martian atmosphere, retaining only the barotropic mode and the leading order baroclinic modes. Our objectives in Part II of the study are to incorporate these approximations into a Proper Orthogonal Decomposition-Galerkin expansion of the spherical quasi-geostrophic model in order to derive hierarchies of nonlinear ordinary differential equations for the time-varying coefficients of the spatial structures. Two different vertical truncations are considered, as well as three different norms and 3 different Galerkin truncations. We investigate each in turn, using tools from bifurcation theory, to determine which of the systems most closely resembles the data for which the original diagnostics were performed.
Avalanches in bi-directional sandpile and burning models: a comparative study
Authors: Gedalin M. , Bregman M. , Balikhin M. , Coca D. , Consolini G. , Treumann R. A. 
Published: April 2010

Abstract. We perform a statistical analysis of two one-dimensional avalanching models: the bi-directional sandpile and the burning model (described in detail in the companion paper by Gedalin et al. (2005) "Dynamics of the burning model"). Such a comparison helps understand whether very limited measurements done by a remote observer may provide sufficient information to distinguish between the two physically different avalanching systems. We show that the passive phase duration reflects the avalanching nature of the system. The cluster size analysis may provide some clues. The distribution of the active phase durations shows a clear difference between the two models, reflecting the dependence on the internal dynamics. Deeper insight into the active phase duration distribution even provides information about the system parameters.
Internal-wave reflection from uniform slopes: higher harmonics and Coriolis effects
Authors: Gerkema T. 
Published: April 2010

Abstract. Weakly nonlinear reflection of internal waves from uniform slopes produces higher harmonics and mean fields; the expressions are here derived for constant stratification and with Coriolis effects fully included, i.e. the horizontal component of the earth rotation vector (referred to as "non-traditional'') is taken into account. Uniformity in one of the horizontal directions is assumed. It is shown that solutions can be as readily derived with as without ; hence there is no need to make the so-called Traditional Approximation. Examples of reflecting internal-wave beams are presented for super-inertial, inertial and sub-inertial frequencies. The problem of resonant and non-resonant forcing of the second harmonic is studied for single plane waves; unlike under the Traditional Approximation, the problem of reflection from a horizontal bottom no longer forms a singular case. Non-traditional effects are favourable to resonant forcing at near-tidal rather than near-inertial frequencies, and generally increase the intensity of the second harmonic. Strong stratification tends to suppress non-traditional effects, but a near-total suppression is only attained for high values of stratification that are characteristic of the seasonal thermocline; in most parts of the ocean, non-traditional effects can therefore be expected to be important.