Seismic activity in the Czech Republic in 2008     

Jan Zedník  Jana Pazdírková 《Studia Geophysica et Geodaetica》2010,54(2):333-338

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Accuracy assessment of the Mexican National Forest Inventory map: A study in four ecogeographical areas     

Stéphane Couturier  Jean‐François Mas  Erna López‐Granados  Jorge Benítez  Valdemar Coria‐Tapia  Álvaro Vega‐Guzmán 《Singapore journal of tropical geography》2010,31(2):163-179

The accuracy of the Mexican National Forest Inventory (NFI) map is derived in four distinct ecogeographical areas, using an assessment design tailored for the project. A main achievement of the design was to integrate the high diversity of classes encompassed at the most detailed subcommunity level of the classification scheme within a cost‐controlled statistically sound assessment. A hybrid double sampling strategy was applied to the 2.5 million‐ha study area. A total of 5955 reference sites were verified against their NFI map label. The availability of detailed quasi‐synchronous reference data for the 2000 Landsat‐derived NFI and the high diversity of mapped classes allowed a careful thematic analysis on the selected regions, relevant for national extrapolation. Global accuracy estimates of 64–78 per cent were registered among the four ecogeographical areas (two with mainly temperate climate and the other two with mainly tropical climate), with the lower accuracy levels found in areas more densely covered with forests. According to the estimates, the NFI map tends to underestimate the presence of temperate forest (especially oak) and overestimate the presence of tropical forest in the areas investigated. The analysis of confusions reveals difficulties in unambiguously interpreting or labelling forests with secondary vegetation, herbaceous and/or shrub‐like vegetation as well as distinguishing between aquatic vegetation types. The design proved useful from the perspective of accuracy assessments of regional maps in biodiverse regions.  相似文献   

Seismicity pattern of the Betic Cordillera(southern Spain) derived from the fractal properties of earthquakes and faults          下载免费PDF全文

J Henares Romero  C López Casado  J Badal  J A Peláez 《地震科学（英文版）》2010,23(4):309-324

Several studies on earthquake occurrence and associated faulting have demonstrated that both phenomena have a scale-invariant behavior which can be analyzed by means of a set of non-integer dimensions(Dq) describing their fractal properties and the calculation of multi-fractal spectra.It is the case that the behavior of these spectra is asymptotic at the ends of the variation interval of q,which is a real number that enters into the definition of the partition function of the dataset.The difference between the extreme values,called multi-fractal spectrum slope,is used to investigate the heterogeneity of the spatial distribution of earthquakes and fault systems.In this paper we focus on the Betic Cordillera,southeastern Spain,which is commonly considered the contact between the Eurasian and African plates and has an important seismic activity in the context of the Iberian Peninsula.Some of the most conspicuous Iberian earthquakes,such as the 1829 mb6.3 Torrevieja and the 1884 mb6.1 Alhama de Granada earthquakes occurred in this mountain range and both reached intensity X.The present work implies a new analysis based on the slope of multi-fractal spectra and referred to the historical seismicity of the region,specifically b-value(frequency distribution of earthquakes respect to magnitude),epicentral location,seismic energy and faulting.On this basis we propose a seismotectonic zonation that is contrasted with the stress state and the geodynamical evolution of the Betic Cordillera.  相似文献   

The effect of nested grid sampling on the parameter estimation of a spatial Gompertz diffusion     

R. Gutiérrez  C. Roldán  R. Gutiérrez-Sánchez  J. M. Angulo 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(4):539-546

This paper evaluates the effects of using data observed on regular nested grids on the parameter estimates of a two-parameter Gompertz diffusion model. This new spatial diffusion process represents a technically more complex stage of Gompertz modeling. Firstly, the diffusion model is introduced through an appropriate transformation of a two-parameter Gaussian diffusion process. Probabilistic characteristics of this model, such as the transition densities and the trend functions, are obtained. Secondly, statistical estimation is considered using data obtained on a regular or irregular grid; the explicit expression of the likelihood equations and the parameter estimators are given for regular grids. Finally, a simulation experiment illustrates the results of this paper.  相似文献   

A multi-scale hierarchical framework for developing understanding of river behaviour to support river management     

A. M. Gurnell  M. Rinaldi  B. Belletti  S. Bizzi  B. Blamauer  G. Braca  A. D. Buijse  M. Bussettini  B. Camenen  F. Comiti  L. Demarchi  D. García de Jalón  M. González del Tánago  R. C. Grabowski  I. D. M. Gunn  H. Habersack  D. Hendriks  A. J. Henshaw  M. Klösch  B. Lastoria  A. Latapie  P. Marcinkowski  V. Martínez-Fernández  E. Mosselman  J. O. Mountford  L. Nardi  T. Okruszko  M. T. O’Hare  M. Palma  C. Percopo  N. Surian  W. van de Bund  C. Weissteiner  L. Ziliani 《Aquatic Sciences - Research Across Boundaries》2016,78(1):1-16

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Classification of river morphology and hydrology to support management and restoration     

M. Rinaldi  A. M. Gurnell  M. González del Tánago  M. Bussettini  D. Hendriks 《Aquatic Sciences - Research Across Boundaries》2016,78(1):17-33

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Source parameters for the 2013–2015 earthquake sequence in Nógrád county,Hungary     

Zoltán Wéber 《Journal of Seismology》2016,20(3):987-999

Between 2013 June and 2015 January, 35 earthquakes with local magnitude M _L ranging from 1.1 to 4.2 occurred in Nógrád county, Hungary. This earthquake sequence represents above average seismic activity in the region and is the first one that was recorded by a significant number of three-component digital seismographs in the county. Using a Bayesian multiple-event location algorithm, we have estimated the hypocenters of 30 earthquakes with M _L ≥1.5. The events occurred in two small regions of a few squared kilometers: one to the east of Érsekvadkert and the other at Iliny. The uncertainty of the epicenters is about 1.5–1.7 km in the E-W direction and 1.8–2.1 km in the N-S direction at the 95 % confidence level. The estimated event depths are confined to the upper 3 km of the crust. We have successfully estimated the full moment tensors of 4 M _w ≥3.6 earthquakes using a probabilistic waveform inversion procedure. The non-double-couple components of the retrieved moment tensor solutions are statistically insignificant. The negligible amount of the isotropic component implies the tectonic nature of the investigated events. All of the analyzed earthquakes have strike-slip mechanism with either right-lateral slip on an approximately N-S striking or left-lateral movement on a roughly E-W striking nodal plane. The orientations of the obtained focal mechanisms are in good agreement with the main stress pattern published for the epicentral region. Both the P and T principal axes are horizontal, and the P axis is oriented along a NE-SW direction.  相似文献   

Exploration of deep sedimentary layers in Tacna city,southern Peru,using microtremors and earthquake data for estimation of local amplification   总被引：1，自引：1，他引：0  

Hiroaki Yamanaka  Mileyvi Selene Quispe Gamero  Kosuke Chimoto  Kouichiro Saguchi  Diana Calderon  Fernándo Lázares La Rosa  Zenón Aguilar Bardales 《Journal of Seismology》2016,20(1):107-116

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Relationship between volcanic ash fallouts and seismic tremor: quantitative assessment of the 2015 eruptive period at Cotopaxi volcano,Ecuador     

Benjamin Bernard  Jean Battaglia  Antonio Proaño  Silvana Hidalgo  Francisco Vásconez  Stephen Hernandez  Mario Ruiz 《Bulletin of Volcanology》2016,78(11):80

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The Disruption Index (DI) as a tool to measure disaster mitigation strategies     

M. A. Ferreira  F. Mota de Sá  C. S. Oliveira 《Bulletin of Earthquake Engineering》2016,14(7):1957-1977

Apart from the loss of lives, injuries and homeless resulting from an earthquake, not only the economy and physical landscape are altered, but also the lives of citizens and their places of work are dramatically altered. If critical services and functions are disrupted for more than a reasonable time period, consequences can be severe. All communities are at risk and face potential disaster, if unprepared. The Disruption Index (DI) is a tool that allows the representation of a complex and multidimensional situation in a concise and easier way, providing institutions and communities with a way to identify the global earthquake impact in a geographical area, the elements at risk, and the means to reduce it. In the present paper, after a short review of the concept of DI, its geographic (spatial) distribution is developed and an application to some cities in Algarve (Portugal) is made. Then, the use of DI in the context of measuring the risk reduction for alternative disaster mitigation strategies is introduced and illustrations are presented.  相似文献