Data Fusion Technique for Multibeam Echosoundings

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新陈代谢GM(1,1)模型在建筑物沉降预测中的应用研究

本文针对传统GM(1,1)模型存在的不足,建立了新陈代谢GM(1,1)沉降预测模型.并以某建筑物沉降为例对比两模型的预测值,结果表明新陈代谢GM(1,1)模型在处理该类数据上更加具有一定的优势.     

青海高寒草甸退化演替中的植被指数

随着气候变化和人为活动干扰,高寒草甸退化已成为青藏高原严重的生态环境问题,精准识别其退化程度并制定相应恢复策略,对实现高寒草甸可持续发展具有重要意义。目前,低空间分辨率MODIS数据为草地遥感监测的主要数据源,但难以满足景观破碎度或异质性较强地区的应用。本研究基于野外调查资料,利用多源遥感数据（MODIS、Landsat、Sentinel-2）研究不同空间分辨率归一化植被指数（NDVI）对高寒草甸退化演替的响应,为准确评估青藏高原高寒草甸退化程度提供依据。结果表明：（1）随着高寒草甸退化,植被群落优势种演化趋势为禾草—矮嵩草—小嵩草—杂草群落;植被高度和生物量先快速下降,然后缓慢下降或趋于稳定,植被覆盖度和NDVI的变化呈相反特征。（2）随着湿地草甸旱化,植被群落优势种从藏嵩草演变为矮嵩草或小嵩草,湿地旱化初期植被高度、生物量和覆盖度平均值略低于原生湿地,NDVI略大于原生湿地,差异不显著。（3）植被高度、覆盖度和生物量与Sentinel-2或Landsat的NDVI相关性均优于MODIS,说明Sentinel-2和Landsat的NDVI对高寒草甸退化演替过程更加敏感,采用该数据能更准确评估高寒草甸退化程度。     

高速铁路与国家地震台网信息接入及资源共享方式研究

本文对高速铁路与国家地震台网信息接入和资源共享方式进行了讨论。通过对组网模式和时延的分析及测试,在遵循目前地震系统信息传输模式的前提下,对于实时波形数据,可以根据实际情况采取国家中心型或者省局中心型的方式进行共享,用于高铁系统台站的补充,在地震预警发布阶段使用;对于地震速报信息,可以采取国家中心型的方式进行共享,用于地震信息的确认,在地震预警解除阶段使用。为了减小实时数据传输的时延以适应预警需求,应对数据采集器进行升级,并更新相应的流服务器的仪器适配器。     

郯庐断裂带新沂－五河段晚第四纪活动的新证据

The Tancheng-Lujiang fault zone has great influence in eastern China. Studies have shown obvious signs of neotectonic activities on the Xinyi-Wuhe segment of the Tancheng-Lujiang fault zone. In this study, on the basis of the previous work, many seismological surveys are made along the Tancheng-Lujiang fault zone and trenches are excavated in key sites. Combined with the analysis of the seismic activities along the fault, the fault movement features and future seismic risk are discussed. Much first-hand information obtained in the paper can provide an important reference value for the study of large earthquake recurrence rules and the mid and long-term earthquake prediction on the Xinyi-Wuhe segment of the Tancheng-Lujiang fault zone.     

郯庐断裂带新沂-五河段晚第四纪活动的新证据

郯庐断裂带对中国东部地区影响重大。已有研究表明,郯庐断裂带新沂-五河段第四纪以来有明显的新活动迹象。本文在前人工作的基础上,围绕郯庐断裂带新沂-五河段开展地震地质调查,在重点地段进行探槽开挖,结合断裂沿线地震活动分析,对郯庐断裂带新沂-五河段活动习性及未来地震危险性等进行了探讨。本文补充的很多第一手资料,可为研究郯庐断裂带新沂-五河段大地震复发规律及地震中长期预测等提供有价值的参考依据。     

中国暴雨洪涝灾害的暴露度与脆弱性时空变化特征

利用1984-2012年中国暴雨洪涝灾害灾情和社会经济数据,从灾害暴露范围、人口暴露度、经济暴露度和农作物暴露度4个方面分析了灾害暴露度的特征,从人口脆弱性和经济脆弱性两方面分析了灾害脆弱性特征。研究表明：1984-2012年,中国暴雨洪涝灾害年平均暴露范围、人口暴露度、经济暴露度和农作物暴露度分别为9.37万km²、126人/km²、149万元/km²和1.53亿hm²,暴露度总体呈显著增加趋势,高暴露区域主要分布在沿海省（市）;人口脆弱性显著增大,但经济脆弱性有逐渐减小的趋势,灾害脆弱性高值区主要分布在长江中游沿岸的湖南、安徽、重庆、江西、湖北等省（市）,上海、北京、天津为灾害脆弱性最低的区域。     

An improved energy‐based approach for selecting pulse‐like ground motions

This study proposes an improved energy‐based approach for quantitative classification of velocity‐pulse‐like ground motions. The pulse amplitude is determined, in its value and in time location, by the amplitude of the half‐cycle pulse having the largest seismic energy. After conducting statistical analyses, a newly‐determined threshold level for selecting pulse‐like ground motions is derived; and then what followed is a comparison analysis of three pulse‐detecting schemes, one using the wavelet analysis, the other two using the energy concept. It is believed that other than providing a useful way of classifying pulse‐like ground motions for structural demand analysis, knowledge of this work could also benefit the development of the ground motion prediction equations accounting for pulse effects, and further to aid the probabilistic seismic hazard analysis in a near‐fault environment. Copyright © 2016 John Wiley & Sons, Ltd.     

Features and origin time of Mesozoic strike-slip structures in the Yilan-Yitong Fault Zone

The NE-striking Yilan-Yitong Fault Zone(YYFZ) with a length of ca. 900 km is an important major fault zone in northeastern China. Its origin has been a controversial issue for a long time. Detailed field investigation and comprehensive analyses show that strike-slip faults or ductile shear belts exist as the origination structures on the both shoulders of the Cretaceous-Paleogene grabens. These strike-slip structures are dominated by brittle transcurrent faults, and appear as ductile shear belts only in the Weiyuanpu-Yehe and Shulan parts in the south and middle of the fault zone, respectively. The shear belts strike NE-SW and show steep mylonitic foliation and gentle mineral elongation lineation. Outcrop structures, microstructures and quartz c-axis fabrics demonstrate a sinistral shear sense with minor reverse component for the ductile shear belts. The microstructures suggest deformation temperatures of 400–450°C for the Weiyuanpu-Yehe shear belts and 350–400°C for the Shulan shear belt. A series of zircon U-Pb dating results for deformed and undeformed plutons or dikes in the shear belts constrain the strike-slip motion to the time between 160 and 126 Ma. It is further inferred from ages of main geological events in this region that the fault zone originated in the earliest Early Cretaceous. It is suggested therefore that the southern and middle parts of the Tan-Lu Fault Zone, which originated in Middle Triassic, propagated into northeastern China along the sinistral YYFZ under the earliest Early Cretaceous regional compression that is referred to as the Yanshan B event. The earliest Early Cretaceous initiation of the YYFZ results from both the high-speed oblique subduction of the Izanagi Plate and the final closure of the Mongol-Okhotsk Ocean, but the Izanagi Plate subduction played a major dynamic role in the fault zone origin.     

21世纪珠江流域水文过程对气候变化的响应

应用HBV-D水文模型和多个气候模式预估了不同温室气体排放情景下珠江主干流西江的径流过程,分析了21世纪水资源量和洪水频率的变化。结果表明：2050年后年降水量和年径流量较基准期（1961—1990年）明显增加;流域平均的月降水量和径流量在5—10月间均呈增加趋势,12月至次年2月呈减少趋势;年最大1 d和7 d洪量逐渐增加,重现期逐渐缩短。2030年前枯水期径流增加有望缓解枯水期用水压力,而2050年之后丰水期径流量以及洪水强度、发生频率的增加将给珠江流域防汛抗洪带来更大压力,在制订气候变化对流域水资源影响适应性对策时应考虑这两方面的影响。