基于GeoSOT-3D的空间对象快速可视化与实验分析   总被引：1，自引：0，他引：1  

李志强  程承旗  李爽 《地球信息科学学报》2015,17(7):810-815

地球空间信息剖分组织,在全球海量、多源、多分辨率数据组织与管理方面表现出了极大的优越性。但全球尺度的空间数据往往数据量大、内容丰富,进行对象表达时需处理的数据量,远远超出计算机硬件的处理能力。鉴此,本文在GeoSOT-3D地球空间剖分框架下,借鉴已有三维快速可视化技术,并顾及GeoSOT-3D自身的全球多尺度划分、无缝无叠、二进制一维整形编码等特性,将现有三维快速可视化方法与GeoSOT-3D剖分框架特性相结合,提出了八叉树索引的空间对象裁剪和消隐策略,实现了GeoSOT-3D框架下空间对象的快速剖分表达。同时,以空间电磁场的表达为例,开发了试验系统,并对结果进行了分析,解决了GeoSOT-3D空间对象表达效率低下的问题。  相似文献   

Conditional LAS stochastic simulation of regionalized variables in random fields     

Samuel Frimpong  Peter K. Achireko 《Computational Geosciences》1998,2(1):37-45

Ore reserves forecasts are required to aid in investment decisions, mine design and valuation, short and long term production plans and proper and efficient mill design. In random multivariable fields with limited data and high levels of uncertainty, the kriged block estimates produce a smoothing effect resulting in underestimating high values and overestimating low values. The modified conditional simulation (MCS) methodology solves these problems by simulating the random field to preserve its mean and the variance structure. The simulation model is conditioned to reproduce the data at known sample points to minimize the variability between the simulated data and the true field data. In this study, the authors develop the MCS methodology to simulate ore reserve grades using the best linear unbiased estimation (BLUE) and the local average subdivision (LAS) techniques. The MCS methodology is applied to simulate block grades in a section of the Sabi Gold Project in Zimbabwe. The results are compared with the kriged estimates for this section. Analysis of the results shows that the MCS methodology reproduces the known sample grades with minimum estimation error of 0.001 while the estimation error associated with the kriged estimates is 1.104, a 100% efficiency of the MCS method over the kriging technique.  相似文献   

Contribution of pits dug by goannas (Varanus gouldii) to the dynamics of banded mulga landscapes in eastern Australia     

Walter G Whitford 《Journal of Arid Environments》1998,40(4):453-457

The densities of pits made by goannasVaranus gouldiiwere estimated in the three distinct zones of banded mulga landscapes (erosion slope, interception zone, and mulga grove) in paddocks of a grazing study in north-western New South Wales, Australia. In light and moderately grazed paddocks, soil pits were significantly more abundant in the interception zones (M=119.057 m⁻²) than in the groves and erosion slopes (M=16.057 m⁻²). In the overgrazed paddock there were no differences in densities of pits in any of the zones. In the groves and erosion slopes approximately 70-80% of the pits contained litter, seeds, and fruits. However, on the erosion slopes less than 20% of the pits contained litter and seeds. The data support the hypothesis that soil disturbance byVaranuslizards produces a positive feedback mechanism for the viability of the interception zone and the functioning of banded vegetation landscapes.  相似文献   

冲绳海槽晚第四纪硅藻生物地层划分与对比     

李超  蓝东兆  石学法  陈承惠 《台湾海峡》2004,23(4):507-513

本文对冲绳海槽中段B孔岩芯中的沉积硅藻进行了分析。共鉴定出52属166种和变种．根据硅藻属种组成、热带远洋种的相对含量以及整个硅藻植物群的变化特征共划分出9个组合带，并对它们的特征进行了描述；结合^14C测年数据。对该岩芯的地层年代归属进行了确定，全新世与晚更新世的界线位于该孔125cm处．上部地层为全新统，下部地层为上更新统；同时与邻近DGKS9603钻孔的硅藻生物地层进行了对比．  相似文献   

Extending a BIM-based data model to support 3D digital management of complex ownership spaces     

Behnam Atazadeh  Mohsen Kalantari  Abbas Rajabifard  Serene Ho  Tom Champion 《International journal of geographical information science》2017,31(3):499-522

Currently, 2D-based analogue building subdivision plans are used to represent the spatial extent of private, public and communal property ownership rights. These plans are recognized as posing a range of challenges in terms of communicating the spatial complexity of ownership spaces within multi-storey buildings. In response to these challenges, three-dimensional (3D) digital data environments are being investigated as a potential approach for managing complex, vertically stratified ownership arrangements. The argument presented in this article is that Building Information Modelling (BIM) can be adopted for 3D digital management of data related to complex ownership spaces. BIM provides a common and 3D digital data sharing space, underpinning a reliable basis for facilitating collaboration and decision-making over the lifecycle of buildings. However, ownership attributes and the spatial structure of ownership arrangements inside buildings are yet to be accommodated within the BIM data environment. In this article, we present a range of required data elements for managing complex ownership spaces, which have been elicited by investigating current practices pertaining to subdivision of ownership spaces within multi-storey buildings in Melbourne, Australia. An open data model in the BIM domain is extended with these data elements and a prototype model for a real multi-storey building is implemented to demonstrate the viability of the extended data model for 3D digital management and visualization of data related to complex ownership arrangements.  相似文献   

基于共生理论的中国特色保护类村庄振兴类型细分研究   总被引：1，自引：1，他引：0  

杨坤  芮旸  李宜峰  杨钰华 《地理科学进展》2021,40(11):1861-1875

特色保护类村庄是国家乡村振兴战略规划确定的4种村庄基本类型之一,但其分异明显,仍需进一步细分类型以精准施策。论文坚持问题导向和理论指引的分类思路,针对特色保护类村庄内蕴的保护与发展对立统一关系,借鉴共生理论构建其共生系统概念模型,根据系统类型及构成的差异划分村庄振兴类型,筛选出8173个国家级特色保护类村庄作为实证研究样本,初步提出一套简便实用的类型识别流程及方法,据此逐层判断样本类型并分类明确振兴模式。结果表明：① 特色保护类村庄共生系统分为外共生型、内共生型和内外共生兼具型3种,存在村庄与外部有机体共生、村庄特色资源与产业共生、村庄特色文化资源与人居环境共生以及村庄特色资源、产业与外部有机体共生等4类共生关系;② 特色保护类村庄振兴类型基于共生关系表征的异同抽象归纳为10种,样本据此细分为47个旅游目的地型、75个文旅融合型、251个农旅融合型、47个特色农业型、442个景区依托型、1463个市场拉动型、2159个交通推动型、160个历史记忆保护型、1543个民族特色保护型和1986个地域文化保护型村庄; ③ 特色保护类村庄振兴模式因类型而异,包括“优化升级、示范引领”“深度融合、增值赋能”“品牌强农、特色集聚”“借力景区、村景互补”“瞄准市场、乡城对接”“联动交通、一体共生”和“活态保护、留住乡愁”7种。  相似文献   

纳米比亚达马拉造山带新元古界朝斯组条带状铁建造的特征及成因     

曹晗  吴昌志  刘援军 《江苏地质》2016,40(4):589-598

以纳米比亚北部台地区的新元古代成冰期朝斯(Chuos)组沉积变质型条带状铁建造为研究对象,通过研究该区的大地构造背景、矿物学、岩石学、地球化学等特征,针对该区域朝斯组地层特征、构造历史、结构构造、矿物组成、形成环境及成因等方面进行研究,结合"雪球地球"假说,认为研究区含铁建造与成冰期的一定条件下的裂谷作用形成海盆和热液组分有直接成因联系,在雪球期内的氧化还原环境多变的裂谷大洋、海底热液流体、大陆风化作用、海洋生物圈变化、大气与海水的物质组分交换等多重因素的作用下,最终导致了含铁条带建造的沉积层序的形成。  相似文献   

一种基于地球剖分网格的方向导向的路径搜索算法     

田方杰  程承旗 《地理信息世界》2016,(4):1-6

路径搜索问题作为地理信息科学等学科的一个研究热点,由此出现的许多路径搜索算法,在交通道路网和导航系统中已得到广泛应用。纵观这些成果,往往需要以构造矢量道路为前提,道路网缺乏地区(如野外、室内)等情况不太适用。由此,本文提出了基于地球剖分网格的以方向主导的路径搜索算法,文中描述了具体的原理和方法,且针对算法设计相应实验验证了该算法的可行性和效率,为路径搜索提出了一种新思路。  相似文献   

碳酸盐岩台地多旋回沉积小层精细划分对比方法研究——以川中磨溪构造嘉二段为例   总被引：4，自引：0，他引：4  

谭秀成  罗冰  李凌  罗玉宏  杨金利  姚晏波  李俊良  邹娟  何秀琼 《地层学杂志》2008,32(2):207-212

以四川盆地川中磨溪构造下三叠系嘉陵江组二段为研究对象,研究海相碳酸盐岩台地多旋回小层精细划分与对比方法。通过对海水咸化旋回、相对海平面变化旋回、古气候变化旋回沉积特征与成因的分析,磨溪地区嘉二段沉积期主要发育潮下型碳酸盐米级旋回层序,沉积界面特征明显并具有一定的成因联系,这种高频沉积旋回具多成因机制特征。在此基础阐明了高频米级旋回的划分原则,提出了一种多旋回沉积界面优选的依据与方法,据此,重新厘定了川中磨溪构造嘉二段小层划分方案。通过精细对比,建立了近于等时的地层格架。该方法有效地避免了单纯运用岩电特征进行地层划分对比时带来的多解性问题,并使各亚段和小层接近于等时的沉积体,为沉积微相及储层的成因和分布研究奠定了可靠的地层学基础。  相似文献   

扬子地台寒武系碳酸盐岩的碳同位素组成及地质意义   总被引：8，自引：0，他引：8  

左景勋  彭善池  朱学剑 《地球化学》2008,37(2):118-128

贵州金沙地区寒武系上部娄山关组岩性单一,为蒸发相白云岩,生物化石稀少,沉积时代归属不清.为寻找地层对比与划分的岩石地球化学标志,按5 m的样品间距对贵州金沙地区相邻的长岩沟剖面、岩孔剖面寒武系采集了250件碳、氧同位素样品进行测试分析,对其演化趋势进行了研究.结果表明,贵州金沙地区寒武系碳同位素组成演化表现出4次显著负漂移和3次显著的正漂移.负漂移分布于清虚洞组中部(NE-1)、陡坡寺组下部(NE-2)、陡坡寺组与娄山关组的分界处(NE-3)、及娄山关组下部(NE-4),δ13C值分别降低到-2.3‰0、-2.6‰o、-6.2‰和-4.8‰;正漂移分布于清虚洞组底部(PE-1)、顶部(PE-2)及娄山关组上部(PE-3),δ13C值分别上升到1.3‰、2.1‰和2.6‰.δ13C的演化趋势可与世界各大陆寒武系δ13C演化趋势对比,它将娄山关组下部、中部、上部分别划归全球寒武系第二统上部、第三统及第四统.  相似文献