论对地方地震工作的科学指导与管理     

朱煌武  陈刚正 《华北地震科学》1993,11(4):1-8

根据现代行政管理学及领导管理科学的要求，研究探讨了我国地方地震工作管理的特殊性及其基本要求，提出了科学指导和管理地方地震工作的总体思路和基本模式，即一个指导思想，两个落脚点，三种管理方法和四条保证措施。作者据此总结了我国地方地震工作管理的实践和发展，提出了当前亟待解决的三个问题。  相似文献   

X射线荧光光谱分析检出限问题的探讨与建议   总被引：12，自引：5，他引：7  

梁国立邓赛文  吴晓军甘露 《岩矿测试》2003,22(4):291-296

对有关X射线荧光光谱分析低含量元素的检出限问题进行了多方面的探讨。从检出限的定义及其定义下的相对标准偏差到各种不同测量、校准与校正方法的检出限及其相对应的相对标准偏差进行计算。提出了以定义检出限的相对标准偏差为基准,对各种测量方法计算出的检出限进行重新界定,从而确认一个具有可比性的、精度一致的检出限。同时还讨论了仪器与X光管固有杂质元素谱线对该元素检出限的影响;测量仪器、测量条件与测量时间对检出限的影响;不同岩性试样对检出限的影响;检出限与测定限等问题。  相似文献   

一种台风路径相似检索的算法研究     

刘勇  吴必文  王东勇 《气象》2006,32(7):18-24

台风路径可视为二维平面上的一段曲线，根据两条台风路径曲线的相似离度可以判断其数值相似和形态相似的程度。由于直接应用台风基本资料进行相似离度计算有一定的难度和局限性，需要研究利用相似离度原理判断两条台风路径曲线相似程度的计算方法。按照设计的算法处理台风基本资料，可以确定两条台风路径曲线上的对应控制点，得到两条曲线对应控制点之间的距离和距离偏差的方向，最终只需在一个方向计算相似离度就能直接分析两条曲线的相似性。对相似台风进行检索的实例表明，该算法是可行的，能够从台风基本资料库中检索出与当前台风路径最相似的台风个例。  相似文献   

Local configuration measures for categorical spatial data: binary regular lattices     

Barry Boots 《Journal of Geographical Systems》2006,8(1):1-24

This paper examines the utility of a number of pattern measures for local exploratory analysis of binary spatial data. Based on a review of existing pattern measures in cartography, geography, image analysis, and landscape ecology, two fundamental classes of such measures, termed compositional and configurational, are identified. The paper focuses on configurational measures and it is suggested that as many as five such measures (join counts, patch numbers, patch sizes, patch proximity, and distribution of the classes relative to the focal cell of the window) are required to differentiate between all possible local categorical maps. This suggestion is explored by examining aspects of the statistical behaviour (probability distributions and correlations between extreme values of pairs of measures) of a set of 12 configurational measures. Their use is also demonstrated by means of an empirical example.  相似文献   

M L Determination for Local and Regional Events Using a Sparse Network in Southwestern Germany     

Stefan Stange 《Journal of Seismology》2006,10(2):247-257

A method for the determination of consistent local magnitude M _L values (Richter scale, or M _WA) for earthquakes with epicentral distances ranging from 10 km through 1000 km is demonstrated. The raw data consists of nearly 1300 amplitude readings from a network of six digital seismographs in Baden–Württemberg (Southwestern Germany) during 26 months starting in 1995, later extended by another 1000 amplitude readings until 1999. Relying on most of the basics introduced by C.F. Richter a three-parameter attenuation curve (distance correction, magnitude-distance relation) for Baden–Württemberg and adjacent areas is presented. Station corrections are evaluated and the attenuation curve is calibrated with respect to other agencies for distances greater than 650 km. Reasonable parametrisations are discussed and meaningful error bars are attributed. Finally, a seventh station is incorporated by means of its station correction alone, without needing to update the attenuation curve.  相似文献   

Relationships between three dispersion measures used in flood frequency analysis     

I. Markiewicz  W. G. Strupczewski  K. Kochanek  V. P. Singh 《Stochastic Environmental Research and Risk Assessment (SERRA)》2006,20(6):391-405

Three dispersion measures of a random variable, i.e., the standard deviation, the mean deviation (MD) about the mean and the second L-moment, are analyzed in terms of their properties and mutual relationships. Emphasis is placed on the MD, as it is less recognized than two other dispersion measures. The relationships between the dispersion measures are derived for distributions commonly applied in flood frequency analysis (FFA). For distributions that are unbounded, there is a distribution-dependent constant value of the ratio of dispersion measures, or equivalently of respective coefficients of variation. For two-parameter distributions that are lower-bounded, the relationship between the coefficients of variation is also distribution dependent and is not linear. For lower-bounded three-parameter distributions, the dispersion measure ratios, or equivalently the ratios of coefficients of variation, depend on the coefficient of skewness and show a strong distributional dependence. For selected distributions, the three dispersion measures are compared both in terms of the robustness to the largest samples element and the accuracy of upper quantile estimation. The MD statistics may be highly competitive to the two other dispersion measure statistics if applied in FFA for parameters estimation.  相似文献   

A radar-based verification of precipitation forecast for local convective storms     

Daniela Rezacova  Zbynek Sokol  Petr Pesice 《Atmospheric Research》2007,83(2-4):211-224

Local flash flood storms with a rapid hydrological response are a real challenge for quantitative precipitation forecasting (QPF). It is relevant to assess space domains, to which the QPF approaches are applicable. In this paper an attempt is made to evaluate the forecasting capability of a high-resolution numerical weather prediction (NWP) model by means of area-related QPF verification. The results presented concern two local convective events, which occurred in the Czech Republic (CR) on 13 and 15 July 2002 and caused local flash floods. We used the LM COSMO model (Lokall Model of the COSMO consortium) adapted to the horizontal resolution of 2.8 km over a model domain covering the CR. The 18 h forecast of convective precipitation was verified by using radar rainfall totals adjusted to the measured rain gauge data. The grid point-related root mean square error (RMSE) value was calculated over a square around the grid point under the assumption that rainfall values were randomly distributed within the square. The forecast accuracy was characterized by the mean RMSE over the whole verification domain. We attempt to show a dependence of both the RMSE field and the mean RMSE on the square size. The importance of a suitable merger between the radar and rain gauge datasets is demonstrated by a comparison between the verification results obtained with and without the gauge adjustment. The application of verification procedure demonstrates uncertainties in the precipitation forecasts. The model was integrated with initial conditions shifted by 0.5° distances. The four verifications, corresponding to the shifts in the four directions, show differences in the resulting QPF, which depend on the size of verification area and on the direction of the shift.  相似文献   

采用掏土纠偏及袖阀管加固技术整治铁路桥涵不均匀沉降     

蒋丹阳 《探矿工程》2007,34(11):15-17,19

某钢筋混凝土箱形铁路桥发生不均匀沉降,经方案优化对比,采用了沉井射水掏土纠偏和塑料袖阀管注浆加固进行综合治理。介绍了其施工工艺和治理效果。  相似文献   

Neo-liberal ruptures: Local political entities and neighbourhood networks in El Alto, Bolivia     

Juan Manuel Arbona 《Geoforum》2007,38(1):127-137

In October 2003, hundreds of thousands of Bolivians took to the streets demanding the resignation of President Gonzalo Sánchez de Lozada. After 20 years of neo-liberal policies - and the failures to improve the living conditions of the majority - the proposal to export natural gas via Chile was taken by the population as yet another step to sustain an unjust political order. Facing a direct challenge by the population the Sánchez de Lozada administration responded with indiscriminate military force. The result was 63 dead and over 300 wounded, which deepened and extended the social rage and eventually forced the resignation of the President. The neo-liberal project - promoted and defended by Sánchez de Lozada - collapsed. The city of El Alto was the epicentre of the challenges to the legitimacy of this political order. This article focuses on the role of local political entities and neighbourhood networks from El Alto in articulating political spaces that challenged the legitimacy of the institutional infrastructure and led to the October 2003 ruptures in the neo-liberal project. Furthermore, I make the case that the particular histories and memories (of “relocalized” miners and indigenous/peasants) that converged in and defined this city were pivotal in the organization of a “political subsoil” that surged to the surface during the October 2003 events.  相似文献   

A Janus-faced biodiversity change and the partiality of ecological knowledge in a world biodiversity hotspot in Ghana: Implications for biodiversity rehabilitation     

Louis Awanyo 《Geoforum》2007,38(4):739-751

The Gyamfiase-Adenya-Obom cluster of villages in the forest-savanna region of Ghana is located within one of Conservation International’s 34 “World Biodiversity Hotspots” of the most biodiversity-threatened regions of the world. In collaboration with local farmers in this area since 1993, the People, Land Management and Ecological Change Project in Ghana (PLEC-Ghana) has been working on promoting biodiversity rehabilitation to address problems of biodiversity change. This goal is expected to be achieved through agrobiodiversity or biodiversity-friendly agricultural practices. However, farmers’ employment of these practices has been lackluster, even while they acknowledge biodiversity changes, dominated by Chromolaena odorata and other herbaceous species, that are driving the decline in forests and their biodiversity. In interpreting the difficulties of biodiversity rehabilitation in Gyamfiase-Adenya-Obom, this study outlines the diverging ecological knowledge of non-residents/outsiders and local farmers about biodiversity change, which it describes as Janus-like with two diverging faces. One face of biodiversity change shows the detrimental impacts on biodiversity and its observers—non-residents/outsiders—insist on biodiversity rehabilitation that nurtures forests, and the growth and domination of tree species. The other face of biodiversity change shows its agronomic advantages and its observers—the local farmers—are skeptical of current biodiversity rehabilitation practices. Farmers see agronomic benefits in biodiversity change, in particular the benefit of faster soil regeneration within the predominant bush fallow system of farming. And as a result of this observation, farmers continue with practices that sustain a decline in forests and biodiversity. Based on social and ecological research that explores three biodiversity-friendly practices promoted by PLEC-Ghana (fallow management, mulching, and intensive weeding to protect tree seedlings), this article discusses the partiality of ecological perspectives that emphasize either face of biodiversity change but not both, and the implications for biodiversity rehabilitation.  相似文献