四川盆地降水变化的区域差异

利用四川盆地实测气象资料、NCEP/NCAR再分析资料以及NCDC全球气温距平资料,分析了四川盆地降水变化的区域差异。结果表明:盆地降水空间异常分布主要呈东西振荡特征,近46 a来,盆西降水显著减少,盆东降水总体变化趋势不明显。青藏高原夏季风指数、西太平洋副热带高压北界和脊线指数与盆地夏季降水的相关场表现为盆西和盆东反号分布,表明高原夏季风和西太副高可能是盆地降水东西振荡分布的重要原因。通过与全球气温变化的回归分析发现,盆地降水变化趋势的区域差异,特别是盆西地区的暖干化可能是对全球变暖的区域响应。     

Spatial-temporal differences in in-stream flow requirement based on GIS： A case study of Yan＇an region,northern Shaanxi

Although water has the central function of the bloodstream in the biosphere especially in arid or semi-arid regions such as Yah＇an region in northwestern China, yet the very limited attention is paid to the role of the water-related processes in ecosystem. In this research, based on continuous nearly 50-year data including runoff volume, sediment discharge as well as sediment accretion from hydrographic stations, and 10-year information of water quality from pollution monitoring stations, the method for measuring in-stream flow requirement has been put forward supported by experiential models and GIS spatial analysis. Additionally, the changes of in-stream flow requirement for environment and economic development have been addressed from spatial-temporal dimensions. The results show that： （1） According to the central streams in Yan＇an region, mean annual in-stream flow requirement reaches 1.0619 billion m^3, and the surface water for economic exploitation is 0.2445 billion m3 （2） Mean annual in-stream flow requirement for sediment transfers in flood period occupies over 80% of the integrated volume in a year. （3） From the 1950s to 1970s, in-stream flow requirement for sediment transfers is comparatively higher, while from the 1980s to 1990s, this requirement presents a decreasing tendency.     

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Alongshore variability of cross‐shore bar behavior on a nontidal beach

We report on a 6‐year nearshore bathymetric dataset from the Danube Delta (Romanian Black Sea coast) that comprises 16 km of erosive, stable and accumulative low‐lying micro‐tidal beaches northward of Sf. Gheorghe arm mouth. Two to three two‐dimensional longshore sandbars exhibit a net multi‐annual cyclic (2.8–5.5 years) offshore migration (20–50 m yr^?1) in a similar way to other coasts worldwide. Bar morphology and behavior on the sediment‐rich accretionary (dissipative) sector differ substantially from that on the erosive (intermediate) sector. Shoreface slope is the most important factor controlling sandbar number and behavior. It determines different wave‐breaking patterns in the surf zone, translated into different offshore sediment transport and bar zone widths along the study site. Additionally, sediment availability, as a result of the distance from the arm mouth and of the long‐term evolution of the coast, controls the sandbar volume variability. These are all ultimately reflected in the variations of sandbar migration rates and cycle periods. A non‐dimensional morpho‐sedimentary parameter is finally presented, which expresses the bar system change potential as offshore sediment transport potential across the bar zone. Copyright © 2016 John Wiley & Sons, Ltd.     

新疆地区县(市)地震应急能力指标体系的建立与区域差异初探

从新疆地区地震活动性、灾害背景及区域协同联动应急模式出发,在遵循科学性、系统优化和可操作性及区域特性等原则的基础上,采用层次分析法建立了县级行政单元的地震应急能力评价指标体系;继而建立了基于基础设施条件、基础人力物力财力、(县级)专项能力和专项经验及基础环境背景4个一类指标集的县(市)绝对地震应急能力综合评价模型,并根据新疆地区4类人员问卷调查资料,计算和分析了样本支持条件下各指标的权重及结果,将其应用在新疆地区县(市)地震应急能力等级划分中。结果表明,地震应急能力的空间分布格局的产生与区域经济发展水平和地理位置等方面所具备的优势是相适应的,安居富民工程对提升区域地震应急能力发挥了重要作用,少数民族聚集区应急能力有待加强,寒旱、高海拔地区等特殊地理因素影响不可忽视。     

敦密断裂带盆地群油页岩特征及成矿差异分析

古近纪敦密断裂带上分布一系列的含油页岩盆地群。根据盆地间构造-沉积充填、岩石组合和油页岩赋存特征,初步确认盆地群中油页岩沉积于湖盆鼎盛阶段,均形成于古近系始新统路特阶。盆地群间油页岩矿床特征存在明显的差别,由西南向东北,油页岩厚度逐渐变小,其沉积环境由深湖到半深湖,再到湖沼,而有机质来源则由湖泊生物为主,到湖泊生物和陆源有机质双向来源,过渡为以陆源高等植物为主。结合含油页岩层系形成于同一时期和相似的古气候背景下,盆地沉降和沉积充填作用是影响油页岩矿床差异的关键因素。长期处于欠补偿环境,可容纳空间大的湖盆利于巨厚油页岩的形成,随着可容纳空间的减少、陆源碎屑供给的增多,油页岩厚度减薄,分布也变得相对局限。深湖和湖沼成因油页岩品质较好,半深湖油页岩品质较差。     

技术关联与城市产业增长研究

动态外部性对于城市产业增长具有显著影响,考察技术关联与城市产业增长之间的关系,并结合产业特征和区域特征构建产业—空间新增长模型,探讨技术关联对城市产业增长的影响机制。采用1998-2008年中国工业企业数据库的数据,研究发现产业特征和区域特征与技术关联存在相互作用,技术密集型产业的技术关联显著促进产业增长,此外东部地区技术关联越高,产业增长越迅速。研究表明,技术关联对城市产业增长的影响具有显著的促进作用,且在不同产业内部和不同区域间存在显著差异。     

Geostatistical approaches to refinement of digital elevation data

Data refinement refers to the processes by which a dataset’s resolution, in particular, the spatial one, is refined, and is thus synonymous to spatial downscaling. Spatial resolution indicates measurement scale and can be seen as an index for regular data support. As a type of change of scale, data refinement is useful for many scenarios where spatial scales of existing data, desired analyses, or specific applications need to be made commensurate and refined. As spatial data are related to certain data support, they can be conceived of as support-specific realizations of random fields, suggesting that multivariate geostatistics should be explored for refining datasets from their coarser-resolution versions to the finer-resolution ones. In this paper, geostatistical methods for downscaling are described, and were implemented using GTOPO30 data and sampled Shuttle Radar Topography Mission data at a site in northwest China, with the latter’s majority grid cells used as surrogate reference data. It was found that proper structural modeling is important for achieving increased accuracy in data refinement; here, structural modeling can be done through proper decomposition of elevation fields into trends and residuals and thereafter. It was confirmed that effects of semantic differences on data refinement can be reduced through properly estimating and incorporating biases in local means.     

用相关分析法检测两种地震计性能及记录数据差异

阐明利用同点记录数据相关性检测两种地震计性能及记录数据差异的方法,并用两台经过测试且性能相同的FBS - 3B型地震计进行验证,最后用该方法检测了STS -2、KS - 2000型地震计的高频段性能及记录数据差异.     

基于频率差异的多次波识别

从简化的海洋地震勘探的基本模型出发,根据一次波和多次波的传播所经介质品质因子的不同,通过理论分析和数值实验证明了随着传播时间的增加,一次波的主频可明显低于同一时间段的海水鸣震主频;提出了将多次波的传播时间和相应主频结合起来判别多次波的"时间-频率识别模式"。实际资料的处理实验表明:与传统的"时间识别模式"相比,基于"时间-频率识别模式"的多次波衰减,可在压制多次波的同时较好地保持有效信号的基本特征。