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631.
Complete records of more than 3,000 earthquake events in the Shanxi, Wenzhou reservoir earthquake sequence were recorded from August to November,2014 by the high-density,high-resolution monitoring stations of the Zhejiang Regional Digital Seismic Network and the reservoir earthquake monitoring network,with a maximum magnitude of M4. 2. Based on 3-D epicenter location, focal mechanism solutions, and in combination with the geological and tectonic characteristics of the reservoir area,the earthquake sequence is discussed in this paper. The linear fitting of the Hypo SAT location results show that the main shock occurred in the NW trending fault and the earthquake sequence is concentrated in bands along the active faults,with a strike of305 °,dipping SW with dip angle of 85 °. By using P-wave first motion symbols, we obtained the average focal mechanism of M ≥ 3. 5 earthquakes,with a strike 308 ° and dip 84 ° for nodal plane II. The field geological survey and research show that the strike,dip and rake of nodal plane II are roughly consistent with the occurrence of the Shuangxi-Jiaoxi fault. The comprehensive analysis reveals that the NW-trending Shuangxi-Jiaoxi fault is the seismogenic structure of the earthquakes. 相似文献
632.
Fettweis M Baeye M Francken F Lauwaert B Van den Eynde D Van Lancker V Martens C Michielsen T 《Marine pollution bulletin》2011,62(2):258-269
The impact of continuous disposal of fine-grained sediments from maintenance dredging works on the suspended particulate matter concentration in a shallow nearshore turbidity maximum was investigated during dredging experiment (port of Zeebrugge, southern North Sea). Before, during and after the experiment monitoring of SPM concentration using OBS and ADV altimetry was carried out at a location 5 km west of the disposal site. A statistical analysis, based on the concept of populations and sub-sampling, was applied to evaluate the effect. The data revealed that the SPM concentration near the bed was on average more than two times higher during the dredging experiment. The disposed material was mainly transported in the benthic layer and resulted in a long-term increase of SPM concentration and formation of fluid mud layers. The study shows that SPM concentration can be used as an indicator of environmental changes if representative time series are available. 相似文献
633.
以可持续发展理论、环境生态学、景观生态学等科学理论为指导,应用"3S"技术和地面观测技术相结合的方法,结合对我国湿地环境质量监测研究的历史与现状,以国内主要湿地类型区的监测信息为平台,共筛选出了湿地景观状况、湿地生物状况、湿地非生物状况、湿地规模等4大类,共计19个监测评价指标,应用层次分析法(AHP),在咨询专家意见的基础上,利用T.L.Saaty的标度法,建立了符合我国国情的湿地环境质量监测的评价指标体系,研究成果可评价全国范围内的湿地环境质量变化规律和发展趋势,为我国的湿地评价、保护和管理工作提供依据。 相似文献
634.
WATANABE Masataka WANG Qinxue HAYASHI Seiji MURAKAMI ShogoLIU Jiyuan OUYANG Zhu LI Yan LI Yingnian WANG Kelin 《地理学报》2005,15(2):131-141
The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, monitor, and assess environmental disasters, degradation, and their impacts in the Asia-Pacific region. The system primarily employs data from the moderate resolution imaging spectrometer (MODIS) sensor on the Earth Observation System- (EOS-) Terra/Aqua satellite, as well as those from ground observations at five sites in different ecological systems in China. From the preliminary data analysis on both annual and daily variations of water, heat and CO2 fluxes, we can confirm that this system basically has been working well. The results show that both latent flux and CO2 flux are much greater in the crop field than those in the grassland and the saline desert, whereas the sensible heat flux shows the opposite trend. Different data products from MODIS have very different correspondence, e.g. MODIS-derived land surface temperature has a close correlation with measured ones, but LAI and NPP are quite different from ground measurements, which suggests that the algorithms used to process MODIS data need to be revised by using the local dataset. We are now using the APEIS-FLUX data to develop an integrated model, which can simulate the regional water, heat, and carbon fluxes. Finally, we are expected to use this model to develop more precise high-order MODIS products in Asia-Pacific region. 相似文献
635.
某高速公路纵穿大断裂带内的山地丘陵区,由于坡体地质条件较差,设计及施工力度欠缺,在2005年6月的强降雨的诱发下,坡体发生了约10万m3的大规模变形,严重影响了高速公路的正常运营。为有效的治理变形坡体,确保公路营运的安全,根据对该变形边坡的现场踏勘,完成了紧急抢险工程设计及综合治理工程设计。根据近两年来的深部位移监测显示,坡体已基本稳定,达到了为抢险施工工程提供科学依据的预期目的。 相似文献
636.
The paper describes the performance of a 5.3-m trial embankment constructed on approximately 45 m of hydraulically placed pulverised fuel ash (pfa). It is planned to redevelop the 17-ha lagoon containing the pfa as a landfill. There is little variation in the particle size distribution of the uniformly graded silt sized pfa over the lagoon. However, the density of the pfa varies with depth with loose material underlying a denser surface layer, in a pattern that probably results from the water level in the lagoon during pfa deposition.
Settlement under the trial embankment was apparently largely complete by the end of the construction period (17 days), with approximately 300 mm of settlement under the crest of the embankment. The embankment settlement is significantly affected by compression of the loose layers within the deposit. Analysis of the problem using the conventional one-dimensional settlement method, and an mv profile determined by CPT calibrated against laboratory tests gave a reasonable prediction of the embankment crest settlement. 相似文献
637.
GPS in dynamic monitoring of long-period structures 总被引:6,自引:0,他引:6
Global Positioning System (GPS) technology with high sampling rates (10 samples per second) allows scientifically justified and economically feasible dynamic measurements of relative displacements of long-period structures—otherwise difficult to measure directly by other means, such as the most commonly used accelerometers that require post-processing including double integration. We describe an experiment whereby the displacement responses of a simulated tall building are measured clearly and accurately in real-time. Such measurements can be used to assess average drift ratios and changes in dynamic characteristics, and therefore can be used by engineers and building owners or managers to assess the building performance during extreme motions caused by earthquakes and strong winds. By establishing threshold displacements or drift ratios and identifying changing dynamic characteristics, procedures can be developed to use such information to secure public safety and/or take steps to improve the performance of the building. 相似文献
638.
遥感和生长模型相结合的小麦长势监测研究现状与展望 总被引:9,自引:0,他引:9
遥感影像的信息波段及其组合可以反映农作物生长的空间信息,可对小麦进行长势监测和产量估算,具有及时性和广域性。生长模型是集气候、土壤、品种和栽培措施等因素为一体的,对作物的物候发育、光合生产、器官建成、同化物积累与分配以及产量与品质形成等生理过程及其与环境和技术因子关系综合量化的动态数学模型,具有机理性和预测性。将二者结合用于长势监测不但具有理论研究价值,还具有广泛的应用前景。本文在简要概述小麦生长模型和长势遥感监测研究进展的基础上,总结了生长模型和遥感相结合的小麦长势监测应用的研究进展,并提出一些今后研究设想。 相似文献
639.
640.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):241-244
In the major physiographic divisions of the north-east of European Russia, temperatures in the cryolithozone and the active/seasonally frozen layer were monitored during the period 1970 to 1995. Active layer depths increased on average by 11% to 15%, whereas the depths of the seasonally frozen layer decreased by 19% to 40%. The largest positive temperature increments, up to 1.2C, were characteristic for the piedmont and basement plains. Lacustrine-alluvial lowlands demonstrated oppositely directed temperature trends depending on a landform. Numerous sites with ongoing permafrost formation demonstrated negative temperature increments varying from 0.1C to 2.0C. 相似文献