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1.
Jantien Stoter Henk de Kluijver Vinaykumar Kurakula 《International journal of geographical information science》2013,27(8):907-924
Noise mapping is the process of determining and visualizing noise impact on the environment in order to support environmental policies. Currently most noise impact studies are based on a 2D approach. The 3D output of noise simulation software is processed and visualized in 2D and combined with 2D topographical and other data, such as population distribution, to quantify the effects. The research described in this paper aims at improving visualization and assessment of noise impact on the environment by generating a 3D noise map in cases where 3D effects are relevant. Based on the specific demand, an approach is presented to generate a 3D noise map as a basis for noise impact studies. The proposed concept is proofed by applying it to a sample noise impact study. From experiences with the sample, it can be concluded that the 3D noise map offers significant insight in situations where 3D noise effects are relevant, i.e. in urban areas. Here, current 2D noise maps have limitations. In addition, more accurate assessment of noise impact is possible in particular when different floors of a building close to the noise source and/or behind noise barriers are considered. This paper also elaborates on accuracy aspects in all phases of noise modelling, including a presentation of initial experiments of 3D noise interpolation. 相似文献
2.
It has been demonstrated both theoretically and experimentally that the Green's function between two receivers can be retrieved from the cross-correlation of isotropic noise records. Since surface waves dominate noise records in geophysics, tomographic inversion using noise correlation techniques have been performed from Rayleigh waves so far. However, very few numerical studies implying surface waves have been conducted to confirm the extraction of the true dispersion curves from noise correlation in a complicated soil structure. In this paper, synthetic noise has been generated in a small-scale (<1 km) numerical realistic environment and classical processing techniques are applied to retrieve the phase velocity dispersion curves, first step toward an inversion. We compare results obtained from spatial autocorrelation method (SPAC), high-resolution frequency-wavenumber method (HRFK) and noise correlation slantstack techniques on a 10-sensor array. Two cases are presented in the (1–20 Hz) frequency band that corresponds to an isotropic or a directional noise wavefield. Results show that noise correlation slantstack provides very accurate phase velocity estimates of Rayleigh waves within a wider frequency band than classical techniques and is also suitable for accurately retrieving Love waves dispersion curves. 相似文献
3.
Eric Calais 《Geophysical Journal International》1999,138(1):221-230
Global Positioning System (GPS) data are analysed from three permanent sites, two in the Western Alps (Grasse, France, and Zimmerwald, Switzerland) and the third in the Po Basin (Torino, Italy), for the 2.5-year period from 1 January 1996 to 1 July 1998. An analysis of the stochastic properties of the position time series reveals a significant amount of spatially and temporally correlated noise, which best fits a model combining white noise and flicker noise. The coloured noise is drastically reduced by spatially filtering the time series, suggesting that it is not due to site-specific effects such as monument motion, but rather to noise sources common to the three sites, such as reference frame, satellite orbit or Earth orientation errors. We find velocity uncertainties (95 per cent confidence interval) of 2.7 mm yr−1 at GRAS, 2.3 mm yr−1 at ZIMM, and 2.9 mm yr−1 at TORI. The residual velocity in the Eurasian reference frame is statistically greater than zero at ZIMM only, with 2.4 ± 2.3 mm yr−1 of motion in a NW direction. These uncertainties place an upper bound on the expected deformation in the Western Alps. Velocities relative to stable Eurasia do not exceed 3 mm yr−1 , corresponding to a maximum strain rate of 0.03 μstrain yr−1 over the GRAS–TORI–ZIMM triangle. 相似文献
4.
长时间序列遥感图像中含有大量的噪声和坏数据,给分类带来困难。该文提出一种新的时间序列特征指标:像元时间序列的简单线性回归系数(SLC),用来提高分类精度。为证明其有效性,设计出一套模拟实验。结果表明:SLC具有较强的抗噪声、抗坏数据能力,有利于提高分类精度,特别是对于植被指数时间序列遥感图像。 相似文献
5.
煤矿区居民的环境污染感知——以陕西省韩城矿区为例 总被引：2，自引：0，他引：2
选择陕西省韩城矿区的下峪口矿和燎原矿为研究区域,通过实地访谈和454份有效问卷,利用秩和检验等统计方法,探讨了居民对环境污染的感知的影响因素。主要结论是:(1)矿区居民对环境普遍不满意,他们认为最严重的环境污染是大气污染,其次是噪音污染。矿区环境污染的最主要原因是煤炭加工(洗选、炼焦),采煤并不是最主要的环境污染原因。(2)在居民属性与环境污染感知方面发现:性别对环境污染的感知无明显的影响。年龄和居住时间对大气污染、水污染和噪音污染的感知有显著正向影响。文化程度对水污染、噪音污染和环境卫生感知有显著负向影响,这与文化集团性有关。居住空间对水污染和噪音污染有显著负向影响,说明水污染和噪音污染感知表现出空间层次性。研究结果可以为矿区的环境治理、政策制定等提供参考。 相似文献
6.
居民环境感知是其环境行为为基础,研究居民属性对环境问题感知的影响,对煤矿区的环境保护社会措施的实施有重要参考意义。彬长矿区是国家重点产煤区,但其环境问题非常严重。通过实地访谈和407份有效问卷的统计,利用秩和检验等方法,探讨了居民对环境问题的感知和调适行为的影响因素,主要结论是：（1）矿区居民对环境普遍不满,他们认为大气污染最严重,其次是环境卫生、噪音和水污染,最后是塌陷和地裂缝。环境问题的最主要原因由采煤和煤炭加工;（2）在居民属性与环境问题感知方面发现：性别对大气污染、水污染、塌陷和地裂缝的感知有明显的影响。年龄属性对大气污染、水污染、噪音污染、塌陷和地裂缝的感知均有显著正向影响。文化程度属性对大气污染、塌陷和地裂缝的感知有显著负向影响。职业属性对各类环境问题的感知均有显著影响。居住时间对噪音污染感知没有显著影响,对其他感知有显著正向影响。居住空间在居民对矿区环境问题的感知上具有显著性负向影响。研究结果可以为矿区的环境治理、政策制定等提供参考 相似文献
7.
Processing seismic ambient noise data to obtain reliable broad-band surface wave dispersion measurements 总被引：28，自引：0，他引：28
G. D. Bensen M. H. Ritzwoller M. P. Barmin A. L. Levshin F. Lin M. P. Moschetti N. M. Shapiro Y. Yang 《Geophysical Journal International》2007,169(3):1239-1260
Ambient noise tomography is a rapidly emerging field of seismological research. This paper presents the current status of ambient noise data processing as it has developed over the past several years and is intended to explain and justify this development through salient examples. The ambient noise data processing procedure divides into four principal phases: (1) single station data preparation, (2) cross-correlation and temporal stacking, (3) measurement of dispersion curves (performed with frequency–time analysis for both group and phase speeds) and (4) quality control, including error analysis and selection of the acceptable measurements. The procedures that are described herein have been designed not only to deliver reliable measurements, but to be flexible, applicable to a wide variety of observational settings, as well as being fully automated. For an automated data processing procedure, data quality control measures are particularly important to identify and reject bad measurements and compute quality assurance statistics for the accepted measurements. The principal metric on which to base a judgment of quality is stability, the robustness of the measurement to perturbations in the conditions under which it is obtained. Temporal repeatability, in particular, is a significant indicator of reliability and is elevated to a high position in our assessment, as we equate seasonal repeatability with measurement uncertainty. Proxy curves relating observed signal-to-noise ratios to average measurement uncertainties show promise to provide useful expected measurement error estimates in the absence of the long time-series needed for temporal subsetting. 相似文献
8.
XIN M.TU 《地理学报(英文版)》1991,(4)
Rank estimation by canonical correlation analysis in multivariate statistics has been proposed as analternative approach for estimating the number of components in a multicomponent mixture.Amethodological turning point of this new approach is that it focuses on the difference in structure ratherthan in magnitude in characterizing the difference between the signal and the noise.This structuraldifference is quantified through the analysis of canonical correlation,which is a well-established datareduction technique in multivariate statistics.Unfortunately,there is a price to be paid for having thisstructural difference:at least two replicate data matrices are needed to carry out the analysis.In this paper we continue to explore the potential and to extend the scope of the canonical correlationtechnique.In particular,we propose a bootstrap resampling method which makes it possible to performthe canonical correlation analysis on a single data matrix.Since a robust estimator is introduced to makeinference about the rank,the procedure may be applied to a wide range of data without any restrictionon the noise distribution.Results from real as well as simulated mixture samples indicate that when usedin conjunction with this resampling method,canonical correlation analysis of a single data matrix isequally efficient as of replicate data matrices. 相似文献
9.
A Preliminary Investigation into the Relationship between Long-Period Seismic Noise and Local Fluctuations in the Atmospheric Pressure Field 总被引：3，自引：0，他引：3
Gordon G. Sorrells 《Geophysical Journal International》1971,26(1-4):71-82
Summary The displacement response of an elastic half space to a plane pressure wave is examined in order to establish the conditions under which sources of this type can contribute significantly to the long-period seismic noise field. The study is restricted to pressure waves which propagate at velocities well below the seismic wave velocities characteristic of the half space. The numerical studies indicate that pressure waves with amplitudes of 100 μbar or more can contribute significantly to the long-period vertical background noise observed at the surface, provided that the detectors are located on sections of alluvial fill or poorly to moderately indurated sandstones and shales whose thicknesses are greater than about a kilometre. These same waves can also create significant tilt noise on long-period horizontal seismographs located at or near the surface, regardless of the rock type. The seismic disturbances created by pressure waves decay rapidly away from the surface. Therefore, it appears that it may be possible to eliminate the effects of atmospherically generated noise by placing the detectors at moderate depths. 相似文献
10.
西方城市社会地理学研究动向分析 总被引：2，自引：0，他引：2
姚华松 《地理与地理信息科学》2006,22(5):101-106
在地理学社会化和人文化的大背景下,人文地理学的重要分支城市社会地理学逐渐成为西方研究的热点。而中国城市地学界一直重经济而轻社会、文化,对城市社会地理学的研究相对滞后。因此,亟须对西方城市社会地理研究成果进行梳理,以期整体把握其研究框架与趋势,为中国城市社会地理学的发展提供借鉴与指导。该文在概念界定基础上,总结1990s以来西方城市社会地理学的研究趋势,归纳西方社会公平、疾病与健康地理、城市管制等研究重点。 相似文献
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13.
国外发达国家城市社区生活空间结构及其规划的研究表明,从20世纪90年代至今,社区资源的可获性研究已成为城市社会-生活空间研究的焦点。本文基于社区体系结构原理,融合以往关于社区资源可获性的研究成果,探索性地总结出社区资源可获性的评价原理以及社区资源可获性相关的评价原则、内容、方法和指标体系。 相似文献
14.
This paper examines prevailing wisdoms on the topic of poverty–environmental interactions, problematizes some standard assumptions and interrogates the geographical literature on the subject. Dominant development discourse has tended to blame the poor for environmental degradation, ignoring the role of other processes and actors at various scales in causing environmental degradation. We examine how definitions of poverty, institutional arrangements, conventional economic models and assumed feedback loops may influence our understanding of poverty–environment interactions. The article gives particular attention to the political ecology approach as a lens through which this dynamic may be understood. Recent work in political ecology has broadened views of poverty–environment interactions by focusing on issues of power, scale and discourse in influencing outcomes and policies. 相似文献
15.
北极黄河科学考察站的GPS站位于挪威斯瓦尔巴群岛,该站对于我国在北极测绘领域的研究具有重要作用。由于极区条件的限制,该站建立在冻土之上,因此需要对其稳定性进行深入研究。本文在利用GAMIT/GLOBK软件处理黄河站及周边IGS站观测数据的基础上,估计了不同噪声模型下的噪声量级、站坐标序列参数和不确定度,分析了黄河GPS观测站与IGS站运动趋势之间的关联性。结果表明,黄河站及周边GPS时间序列不仅存在白噪声,还存在较大量级的闪烁噪声,个别站的一些分量还存在随机游走噪声,仅考虑白噪声会低估总噪声和参数不确定度;黄河GPS站与邻近的NYAL站相比,两者的水平和垂直运动趋势完全一致,仅在垂直方向上有2.15 mm·a~(–1)的差异。 相似文献
16.
D. J. Webb 《Geophysical Journal International》1982,70(1):261-271
Summary. A model of the tides in a hemispherical ocean is used to investigate the effect of changes in the Earth's rotation rate on the power dissipated by the ocean tides. The results obtained are then used in an idealized astronomical model to investigate how they affect the history of the Earth—Moon system.
Using the tidal model it is found that at rotation rates higher than that of the present Earth, the power dissipated by the semi-diurnal tides in the ocean drops off rapidly as a result of the increased tidal frequency. Thus if the Earth's rotation rate is doubled from its present value, then the rate of energy dissipation in the ocean is reduced to approximately one-third of its present value and the tidal torque is reduced by a factor of about 6.
The present value for secular acceleration of the Moon, calculated from the results of the tidal model is -30.5 arcsec century-2 . Using this value in the astronomical model, which has the Moon and Sun in circular orbits above the equator, and assuming that the tidal torque is independent of the tidal frequency, the Gerstenkorn event is predicted to have occurred 1.3 × 109 yr ago.
When the astronomical model is run with a torque determined at all times from the tidal model, the reduction in the energy dissipated early in the history of the system, leads to a Gerstenkorn date of 5.3 × 109 yr ago. However, dissipation within the solid earth is found to be important early in the history of the system and when this effect is included it gives a date for the Gerstenkorn event of 3.9 × 109 yr ago. 相似文献
Using the tidal model it is found that at rotation rates higher than that of the present Earth, the power dissipated by the semi-diurnal tides in the ocean drops off rapidly as a result of the increased tidal frequency. Thus if the Earth's rotation rate is doubled from its present value, then the rate of energy dissipation in the ocean is reduced to approximately one-third of its present value and the tidal torque is reduced by a factor of about 6.
The present value for secular acceleration of the Moon, calculated from the results of the tidal model is -30.5 arcsec century
When the astronomical model is run with a torque determined at all times from the tidal model, the reduction in the energy dissipated early in the history of the system, leads to a Gerstenkorn date of 5.3 × 10
17.
《Geophysical Journal International》1964,8(4):356-369
Summary. This paper describes the results of measurements of the magnetic remanence and anisotropy of susceptibility of some Swedish varved silts. An attempt has been made to observe in nature the effects, which have been demonstrated in the laboratory, of water currents on these properties and to obtain new data on the effects of slopes on the direction of remanence.
It was not possible to obtain quantitative confirmation of the effects of water currents though it is shown that the field results fit qualitatively with those from the laboratory and that the effects of currents may in favourable circumstances be neglected or corrected for. By combining the new data on the effects of slopes with those previously published it has been found possible to demonstrate the importance of grain size in determining the magnitude of the bedding error correction and an expression has been found which gives this correction to an accuracy comparable with the error of measurement of remanence direction.
It is concluded that, since all known systematic deviations of the remanence direction may now be corrected for, it should be possible, in suitable circumstances, to obtain reliable estimates of field directions over the last 10,000 years from measurements on the Swedish varves. 相似文献
It was not possible to obtain quantitative confirmation of the effects of water currents though it is shown that the field results fit qualitatively with those from the laboratory and that the effects of currents may in favourable circumstances be neglected or corrected for. By combining the new data on the effects of slopes with those previously published it has been found possible to demonstrate the importance of grain size in determining the magnitude of the bedding error correction and an expression has been found which gives this correction to an accuracy comparable with the error of measurement of remanence direction.
It is concluded that, since all known systematic deviations of the remanence direction may now be corrected for, it should be possible, in suitable circumstances, to obtain reliable estimates of field directions over the last 10,000 years from measurements on the Swedish varves. 相似文献
18.
“两规”新旧土地利用分类体系比较 总被引：2，自引：0，他引：2
近年来“两规”衔接已成为一个重要的研究课题,“两规”新用地分类体系的先后发布给“两规”衔接带来了契机。运用比较分析方法研究了“两规”新、旧用地分类体系的相互关系,将“两规”用地分类体系的关系演变划分为1997年以前相互独立发展、1997-2006年相互冲突和2006年以来相互衔接3个时期。“两规”旧用地分类体系的比较表明两者在分类重点、分类体系构成、建设用地分类方法和空间范围4个方面的矛盾和冲突最明显。“土规”新、旧用地分类体系的比较表明有4个方面的特征变化：①现状、规划两套分类体系由相互分离转变为相互衔接;②现状分类由三级体系变为二级体系;③在建设用地分类中突出考虑了行业因素;④增强了规划分类的弹性空间。“城规”新、旧用地分类体系的比较分析表明有2个方面的特征变化：①增加城乡用地分类体系;②修订城市建设用地分类体系。最后构建了“两规”新用地分类体系的对应关系。 相似文献
19.
Three-dimensional inversion without blocks 总被引：12，自引：0，他引：12
Summary. We propose a method for solving non-linear inverse problems in the case where the unknown is a function of the spatial coordinates and the data set is discrete and finite. The method is based on a generalized leastsquares criterion, it is defined directly for non-linear problems (without previous linearization of the forward problem), and in the particular linear case it gives the same results (although slightly more general) than the Backus & Gilbert approach. As an example, we apply the method to the three-dimensional seismic velocity inverse problem, using as data the arrival times of seismic waves. The following paper (Nercessian et al .) shows some esults obtained using the present method. 相似文献
20.
This paper questions the main techniques of mapping in the context of aircraft noise in the vicinity of airports, and compares these techniques in terms of their purpose, benefits and limitations. Then the paper describes a method to summarise radar traces of a given air transport departure or arrival route into a median route and its envelope containing 80% of flights. This makes it possible to map global and easy-to-read maps of current air procedures around airports based on actual pathways flown by the aircraft. It also makes it possible to investigate the impact of change in aeronautical procedures on the actual geography of air routes around airports. Such maps complement noise contour maps and offer a good basis for debating aeronautical procedures at airports whose operations expose the population to noise. 相似文献