堰塞湖排险过程中的水文计算探讨

地震、滑坡等原因都能造成河道堵塞形成堰塞湖.堰塞湖的危害:一是上游的淹没灾害,二是溃决后对下游的冲毁及淹没灾害.要妥善处理堰塞湖,减少灾害损失,需要掌握一些水文信息.本文提出了解堰塞湖六个方面的基础信息,探讨如何计算堰塞湖里的蓄水量、堰塞湖溃坝流量及沿程最大流量.目的是为决策者提供基础水文信息,帮助领导正确决策,减少次生灾害的发生.     

堰塞湖应急处置实践与认识

堰塞湖是由于山体滑坡、崩塌、泥石流等堵塞河道形成的没有经过专门设计、没有专门的泄水设施的湖泊,一旦溃决,容易给下游造成巨大的灾难。分析了堰塞湖的成因、溃决机理与风险判断,提出堰塞湖应急处置的原则、理念、阶段与处置方法,总结了堰塞湖应急处置中的一些经验和认识。以四川省汶川特大地震形成的堰塞湖应急处置为例,从可能溃决方式、溃坝洪水、应急除险总体方案、开渠引流方案和除险效果等方面,介绍了唐家山堰塞湖的应急处置实践,并简要介绍了其它一些堰塞湖应急处置。     

无人机遥感图像及其三维可视化在汶川地震救灾中的应用

在分析了无人机低空遥感影像几何变形原理,对无人机遥感数据进行图像拼接与几何校正,正射精校正等处理后与高精度DEM融合,制作出了研究区景观的三维遥感虚拟动态模型。通过分析三维可视化图像,结合地形资料,对汶川地震重灾区安县荼坪河流域由山体滑坡和崩塌等地貌变化造成的堰塞湖和相关灾害,进行了高分辨率、低空遥感的灾害信息获取和灾情评估。实践表明,在灾害应急和复杂地形条件下,使用无人机低空遥感及其三维可视化技术,进行实地数据采集和信息提取,能够对震后各种实时情景进行精确描述,为决策者提供了准确、详细、及时的第一手资料,从而最大限度地减少损失。     

地震诱发堰塞湖的应急水文分析方法与实践

本文运用事件分析方法,在分析突发事件水文应急分析要求的基础上,结合当前应用模式,提出了应急水文分析方法框架模型,并示例说明了在四川"5·12"地震后堰塞湖除险处置过程中不同阶段的应用情况.这些方法对于其他突发事件的水文应急分析也有借鉴意义.     

地震诱发的堰塞湖初步研究

由于地震引发山体滑坡并堵塞河道形成的湖泊称为地震堰塞湖。据统计,我国自1856年以来,共计产生141个地震堰塞湖,按照其形成和造成的灾害来看,堰塞湖可以分为3类:高危型堰塞湖、稳态型堰塞湖和即生即消型堰塞湖。高危型堰塞湖由于蓄水量大、落差大,往往在形成后几天至几年后会被冲垮,形成严重的地震滞后次生水灾。稳态型堰塞湖(亦称“死湖”),可以存在很长时间且湖积水量很大。即生即消型堰塞湖为震时形成的短时堰塞湖,很快会被后来累积的水体冲毁,一般危害不大。如果简单的用时间来区分堰塞湖的类型,那么在一天或者几天内溃决的是即生即消型堰塞湖;几天至100年溃决的是高危型堰塞湖;溃决时间超过100年者,是稳态型堰塞湖。     

青藏高原东北缘黄河上游滑坡与堰塞湖研究进展

随着黄河流域生态保护与高质量发展上升为国家战略,滑坡灾害防治成为迫切需要攻克的基础性问题。另外,黄河上游地区因地形高差大、古地震及强降雨事件频繁,诱发的滑坡及滑坡堰塞湖数量多、分布广、危害重,是近年来滑坡发育和演化机制以及滑坡堰塞湖溃决效应研究的热点。本文在综合整理该地区已有研究工作的基础上,结合笔者研究团队近20年来所获得的滑坡调查评价、测试分析和防灾减灾研究成果,系统归纳了黄河上游地区滑坡调查与风险评价、滑坡时空展布规律及主控因素研究、典型滑坡堰塞湖的续存时长及溃决危害、古滑坡堆积体开发利用及防灾减灾等方面的研究进展和成果,提出了未来在该地区研究古滑坡、堰塞湖沉积与河流阶地以及堰塞湖溃决效应等应关注的4个科学问题。研究结果对于揭示黄河上游地质历史时期滑坡发育和堰塞湖形成的主控因素,探讨滑坡发育的动力机制对地震和降雨的响应过程,拓展第四纪地质学在古滑坡形成演变方面的应用研究等具有重要参考价值。     

金沙江上游特米古滑坡堰塞湖形成与溃决时间讨论

开展古滑坡堰塞湖形成演化过程研究,可以揭示古灾害地质环境效应,重建区域构造历史活动序列和古气候演变特征。特米古滑坡发育于金沙江上游巴塘段,滑坡堆积地貌和堰塞湖相沉积物保存较好,是研究区内古地质环境的良好载体。在遥感解译、无人机测绘、现场调查和地质测年的基础上,结合前人研究成果,分析探讨了特米古滑坡发育特征、堰塞湖形成时间与溃决演化过程。结果表明,特米古滑坡是特大型岩质历史堵江滑坡,滑坡堰塞湖实际形成时间应该远早于2.15 ka BP,历史上曾发生过多次溃决,完全溃决时间大约为1.08 ka BP,堰塞湖稳定保存时间大于1.07 ka。金沙江巴塘段大型堵江滑坡群并非由单次地质事件形成,而是由金沙江断裂带多次强烈地震诱发。     

对地观测技术用于汶川和玉树地震灾害的研究

汶川、玉树大地震造成了重大人员伤亡和财产损失。地震发生后,对地观测技术成为地震灾害监测与灾情评估的重 要手段。本文将从三个方面论述对地观测技术在上述地震灾害评估和研究中所发挥的作用：一是利用高分辨率光学对地观 测技术,建立堰塞湖、道路损毁、崩塌/滑坡/碎屑流等次生地质灾害的遥感分析方法和模型,系统监测汶川地震次生地质 灾害的空间分布、损毁范围、风险程度;二是利用宽幅和干涉两种模式SAR数据,分析玉树地震的区域地质构造和岩性分 布特征,获得玉树地震同震形变场大小及其空间分布信息,证明了多模式SAR在地震灾情协同分析与评价中的有效性和重 要潜力;三是建立了地震灾害三维模拟评估系统,提高了对地震灾害三维模拟的精确性,为地震灾情的精确三维评估提供 了系统平台。     

多层次多尺度的区域性震害预测模式

地震应急反应能力和灾害救援组织的效能是评价一个地区防震减灾水平的重要尺度。为了提高地震应急救援工作的能力 ,福建省地震局震害预测项目组采用多层次、多空间尺度的城乡震害预测技术途径和系统研究原则 ,以适应不同层次的地震应急、救援决策、组织指挥工作的需要。     

面向灾害应急响应的地质灾害链知识图谱构建方法

知识图谱是形式化描述实体及其相互关系的知识系统,其在应急救灾、时空预测决策等方面发挥着重要的作用.灾害应急领域面临数据骤增而应急关键知识匮乏问题,由此从灾害链角度分析地质灾害发展过程中关联的诸多要素,提出了一种自顶向下和自底向上结合的地质灾害链知识图谱构建方法 .首先,基于灾害链角度对地质灾害间复杂形成机理及成链规律进行分析,在已有地质灾害知识基础上,基于自顶向下方法建立了统一的用于信息抽取的地质灾害链本体语义表达框架,包括描述地质灾害知识体系的地质灾害事件本体、承载地质灾害发生的地质环境本体、受地质灾害作用下的地理对象本体及地质灾害在灾前、灾中和灾后时空过程中对应的应急处置方法本体;其次,结合自底向上方法构建数据层,通过知识融合、知识存储对概念、实例与属性等要素及其关联关系进行识别;最后以汶川地震为例并对知识图谱进行可视化表达.结果表明,本方法能有效地对四类要素及其关系进行识别,实现了数据-信息-知识的转换,为地质灾害领域的知识图谱构建提供技术参考.     

Relationships between the acoustic characteristics and physical and deformation properties of clay soils

The search for relationships between deformation characteristics of soils obtained by engineering-geological (direct) and seismoacoustic (indirect) methods is an important problem in modern science. An attempt is made to analyze the influence of a number of factors on the velocity of elastic waves and deformation characteristics of model clay soils.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

A geo-ontology-based approach to decision-making in emergency management of meteorological disasters

Ontology as a kind of method for knowledge representation is able to provide semantic integration for decision support in emergency management activities of meteorological disasters. We examine a meteorological disaster system as composed of four components: disastrous meteorological events, hazard-inducing environments, hazard-bearing bodies, and emergency management. The geospatial characteristics of these components can be represented with geographical ontology (geo-ontology). In this paper, we propose an ontology representation of domain knowledge of a meteorological disaster system descending from an adapted geospatial foundation ontology, designed to formally conceptualize the domain terms and establish relationships between those concepts. The class hierarchy and relationships of the proposed ontology are implemented finally at top level, domain level/task level, and application level. The potential application of the ontology is illustrated with a case study of prediction of secondary disasters and evacuation decision of a typhoon event. The multi-level ontology model can provide semantic support for before-, during-, after-event emergency management activities such as risk assessment, resource preparedness, and emergency response where the formed concepts and their relationships can be incorporated into reasoning sentences of these decision processes. Furthermore, the ontology model is realized with a universally used intermediate language OWL, which enables it to be used in popular environments. This work will underlie the semantic integration among human beings, between heterogeneous systems and between human beings and systems, enable spatial semantic reasoning, and will be useful in guiding advanced decision support in emergency management of meteorological disasters.     

空间关系及其应用

GIS中的空间关系主要描述空间对象之间的各种关系,为GIS的分析提供基本的理论和方法支持。空间关系主要包括距离关系、方向关系、拓扑关系及空间关系相似性等。从空间关系的内涵来讲,空间关系模型应该能够反映目标尺度、人类认知、目标层次、现象的不确定以及随时间变化等特性对空间关系的影响;从数学角度来看,空间关系模型必须是可形式化和可推理的,以方便操作和实现;空间关系从人们认知的角度对空间现象和目标间的关系进行建模,因而在空间数据查询、检索、空间数据挖掘、空间场景相似性评价以及图像理解等应用领域得到了广泛应用。现有GIS模型主要针对二维平面的简单对象、确定的现象进行建模,因而大多数空间关系模型只描述和推理二维平面对象和确定现象的空间关系,三维空间关系、不确定空间关系、复杂目标间的多层次空间关系推理、遥感图像空间关系的抽取、描述与推理将是未来空间关系研究和发展的重要方向。     

地下空间逾渗与裂缝属性的关系分析

裂缝连通性评价是地下空间研究的重要内容。逾渗分析是研究裂缝网络连通性的一种有效手段。裂缝网络逾渗临界值多使用裂缝间接表征参数(如分形维数)来确定,但存在裂缝网络连通性不同却有相同间接表征参数的情况,这降低了预测的可靠性。为避免此类问题并更加准确快速地表征裂缝网络的连通性,文章在构建逾渗临界值方程时,摒弃了间接参数简化的方式,使用裂缝直接表征参数(如裂缝数量、长度等)进行非线性拟合。通过二维数值模拟建立不同参数的离散裂缝网络模型,分析逾渗低、中、高概率临界条件与裂缝直接表征参数的关系,建立逾渗临界条件预测方程,并对方程在不同尺度研究区的应用进行了讨论和验证。结果表明：预测方程可有效地预测不同概率的逾渗临界值。同时文章在预测方程的基础上,建立了裂缝网络连通性评价标准,这对于裂缝发育地区的地下空间评价工作具有一定的指导和借鉴意义。     

Privacy, reconsidered: New representations, data practices, and the geoweb

Blogging, social networking, and other Web 2.0 practices have sparked widespread debate about the status and future of privacy. This paper examines an explicitly geographical aspect of Web 2.0 with respect to these debates: the geospatial web, or ‘geoweb’. As part of fundamental shifts in the kinds of geographic information available, its circulation, and representative forms it assumes, the geoweb implies new objects of privacy concern and subsequent privacy-related negotiations over the aggregate of its component information, technologies, and data praxes. Thus we argue that privacy must not only be revisited, but indeed re-conceptualized. Whereas prior research on privacy vis-à-vis geographic information technologies has tended to question what privacy ‘is’, we focus instead on the constitutive outcomes of societal struggles over privacy. We examine how privacy is being negotiated around two geoweb services - Google Street View and the Twitter GeoAPI - to illustrate that these contestations produce privacy as a social object in particular ways. We show that public discourse around actual or anticipated privacy harms stemming from geoweb services and their uses, as well as the preventatives and remedies proposed or implemented to address such harms, reconstitute the objects and practices of privacy concern, and alter the roles and relationships of state, civil and corporate actors in the construction of privacy. Finally we suggest that the geoweb raises new privacy concerns because some of its representational forms - namely geo-tagged images and self-authored texts - facilitate identification and disclosure with more immediacy and less abstraction.     

Recording and analyzing geospatially accurate structural data through ‘digital mapping’ technique: A case study from the Canisp Shear Zone,NW Scotland

Spatial accuracy of structural data is an important factor for construction of a properly scaled model of crustal structures. Digital Geological Mapping methods can add the required spatial accuracy to the data, and also can improve the versatility of the geological/structural map in many ways, which are difficult to achieve through conventional mapping techniques. The present paper describes the methodology of digital mapping and discusses its applicability in structural analyses in the Canisp Shear Zone (CSZ) — a reactivated continental basement structure in the Precambrian Lewisian Gneiss complex of NW Scottish Highland. The CSZ is reinterpreted as a major dextral transpressional shear zone developed during Laxfordian deformation. It overprinted an earlier Inverian shear zone fabric, and was later reactivated and/or overprinted by brittle shearing of different phases and different scales. Spatial analyses within the ArcGISTM environment has helped bring out the geological relationships between different types of structural data in the shear zone, highlighting the partitioning of deformation into zones of high and low strain. A kinematic interpretation based on the geospatial data analysis, combined with conventional stereographic projection technique, is presented.     

基于规则库的三维空间数据模型

三维空间对象的形式复杂多样,对象之间的空间关系尚未形成共识.三维空间数据模型的空间及非空间关系的表达更是难以统一.典型的三维空间数据模型包括面向实体型、面向关系型和混合型3种数据模型,但这些模型存在诸如拓扑操作困难、对象语义描述不完整、关系表达欠缺等一系列不足.通过分析、综合3种模型的优缺点,以顾及拓扑面向实体的三维矢量数据模型为基础,设计了基于规则库的三维空间数据模型.这是一个将关系与对象相统一的新型数据模型.通过对对象关系的分析研究,引入规则的概念,进而构建出规则库,提出对空间对象间关系和结构统一的,完整的表达和管理方式.结合地质、矿山等应用将该三维空间数据模型在多个城市的三维地质应用中进行成功验证.通过应用,说明该模型实现了空间对象的自身结构和对象之间关系的统一表达,具备自定义、可扩展的空间对象关系表达能力,能够适应复杂应用要求,具有良好的应用前景.      

High‐resolution remote sensing and GIS techniques for geobase data supporting archaeological surveys: A case study of ancient Doliche,southeast Turkey

The detection, surveying, and analysis of ancient settlement structures using remote sensing techniques offer a unique opportunity to quickly map the locations of archaeological objects in a relatively short time. High‐resolution images contribute information to the documentation and spatial relation of these objects, especially if Geographic Information Systems (GIS) and Web‐based applications are used. The aim of this study was to assess the potential use of satellite data and aerial imagesacquired by a remote‐controlled balloon to generate geospatial data with a range of resolutions and information depths. The study area was Doliche, in the landscape of ancient Commagene (Turkey), where conventional flight campaigns are impossible or strongly restricted. Recently generated data sets (i.e., topographic maps, ortho‐images, terrain models) were combined with field observations to derive ancient and modern landscape patterns and their possible relation to an assumed “ancient procession road” between the village Doliche (Dülük) and the nearby sanctuary of theRoman divinity Iupiter Dolichenus. © 2010 Wiley Periodicals, Inc.     

Service-oriented approach for geospatial feature discovery

Rapid increases in remote sensing capability have made remotely sensed images an importance source for intelligence analysts to discover geospatial features. The overwhelming volume of routine image acquisition has greatly outpaced the increase in the capacity of manual image interpretation by intelligence analysts, and prompted automated methods for geospatial feature extraction from high spatial resolution images. Nevertheless, existing methods focus on automatic extraction of isolated or elementary features, such as buildings and roads. A compound geospatial feature, such as a Weapon of Mass Destruction (WMD) proliferation facility, is spatially composed of elementary features (e.g., containment buildings, cooling ponds, and fences). The spatial relations among elementary features can assist the detection of compound features from images. This paper proposes a service-oriented approach for discovering compound geospatial features. The approach includes both a chaining strategy and an architecture. The chaining strategy is to discover sites of facilities by orchestrating services that compute spatial relations among elementary features. The architecture is a service-oriented framework to support the chaining for feature discovery. The approach not only takes advantages of spatial characteristics of complex features, but also enjoys the openness and flexibility of the Service-Oriented Architecture (SOA). A prototypical implementation is provided to illustrate the applicability of the approach.