10～30d延伸期天气预报方法研究进展与展望

10~30 d延伸期预报是国际大气科学关注的研究热点。这一时间段的预报对开展防灾、救灾工作具有极其重要的价值和意义,该工作需要结合初始气象条件、海洋、大气以及气候的影响因素,其中观测资料具有复杂性、综合性、全球性等,这些科学大数据反映和表征着复杂的自然现象与关系,具有高度数据相关性和多重数据属性,预测过程十分复杂。分析了延伸期预报的各种主流方法,其中重点介绍了动力模式、经典统计和大数据方法 3类预报方法的研究现状,并探讨了各种方法的优势和不足,在此基础上对目前延伸期预报领域存在的问题进行了讨论和总结。对延伸期预报方法的未来发展方向和应用前景给以展望。     

大数据正在引发地球科学领域一场深刻的革命——《地质科学》2017年大数据专题代序

本文针对目前国内大数据研究的现状,着重分析了在地球科学领域大数据研究落后的原因,指出大数据正在引发地球科学领域一场深刻的革命,大数据的关键不在于数据的大,而且在于思维的新;从数据出发,让数据说话,依靠人工智能方法,让机器学习、深度学习、可视分析等大数据技术逐步成为必需。利用大数据方法研究玄武岩构造环境判别图以及中新世岩浆事件的意义所取得的成果即是极佳的研究范例。文中指出,面向未来,大数据对于地球科学界来说,决不是可有可无的,它将创造奇迹。大数据作为第四科学范式的研究领域十分宽广,它将改变地球科学家的思维方式,从逻辑思维方式转变为由数据驱动的关联思维方式,文中呼吁科学界对大数据给予更多的关注和支持。     

Influence of rock strength on the valley morphometry of Big Creek, central Idaho, USA

Analysis of valley morphometry and bedrock strength along Big Creek, central Idaho, shows that valley floor width is strongly controlled by bedrock. We performed statistical analysis of Schmidt hammer rock strength as a function of lithology and aspect and of valley morphometry as a function of rock strength. Rock strength is significantly greater on the south side of the valley and in Eocene granodiorites. Rock strength is weakest in Eocene volcanic tuffs. Valley floor width depends negatively on weakest valley-side rock strength, and hillslope gradient on the north side of the valley depends positively on rock strength. Stream gradient does not depend on rock strength. Valley floor width appears to be controlled by bedrock strength on the weaker side of the valley, which was generally the north (south-facing) side. We speculate that a higher degree of weathering via freeze–thaw cycles contributes to lower strength on the north side. The positive dependence of hillslope gradient on rock strength on the north side provides evidence that differential weathering across lithologies determines the gradient that can be maintained as lateral migration of the stream erodes valley walls. These results suggest that in situ rock strength exerts strong influences on some measures of valley morphometry by modulating hillslope mass wasting processes and limiting lateral erosion.     

Building geospatial infrastructure

ABSTRACT

Many visions for geospatial technology have been advanced over the past half century. Initially researchers saw the handling of geospatial data as the major problem to be overcome. The vision of geographic information systems arose as an early international consensus. Later visions included spatial data infrastructure, Digital Earth, and a nervous system for the planet. With accelerating advances in information technology, a new vision is needed that reflects today’s focus on open and multimodal access, sharing, engagement, the Web, Big Data, artificial intelligence, and data science. We elaborate on the concept of geospatial infrastructure, and argue that it is essential if geospatial technology is to contribute to the solution of problems facing humanity.     

All pixels are useful,but some are more useful: Efficient in situ data collection for crop-type mapping using sequential exploration methods

A precise knowledge of the crop distribution in the landscape is crucial for the agricultural sector to inform better management and logistics. Crop-type maps are often derived by the supervised classification of satellite imagery using machine learning models. The choice of data sampled during the data collection phase of building a classification model has a tremendous impact on a model's performance, and is usually collected via roadside surveys throughout the area of interest. However, the large spatial extent, and the varying accessibility to fields, often makes the acquisition of appropriate training data sets difficult. As such, in situ data are often collected on a best-effort basis, leading to inefficiencies, sub-optimal accuracies, and unnecessarily large sample sizes. This highlights the need for new more efficient tools to guide data collection. Here, we address three tasks that one commonly faces when planning to collect in situ data: which survey route to select among a set logistically feasible routes; which fields are the most relevant to collect along the chosen survey route; and how to best augment existing in situ data sets with additional observations. Our findings show that the normalised Moran's I index is a useful indicator for choosing the survey route, and that sequential exploration methods can identify the most important fields to survey on that route. The provided recommendations are flexible, overcome the main logistical constraints associated with in situ data collection, yield accurate results, and could be incorporated in a mobile application to assist data collection in real-time.     

地震信息化共用服务平台设计与实现

随着信息技术的飞速发展和信息化的推进,各个项目建设均要对硬件、网络、数据库、软件平台和系统进行重复的规划与建设,项目建设的系统越多,操作系统和应用服务的部署和运维就面临着越大的挑战,同时也造成了大量硬件资源的浪费,需要较高的成本进行维护.本文介绍了地震信息化项目中,利用云计算和大数据技术构建地震信息化共用服务平台,通过...     

大数据时代城市时空间行为研究方法

信息技术的快速发展带来了“大数据”时代的到来,改变了城市的空间组织和居民行为,并使得城市时空间行为研究方法面临变革。本文在总结传统城市时空间行为研究方法存在问题的基础上,对影响其变革的数据获取与处理技术进行梳理,重点从居民时空行为、城市空间及城市等级体系3个方面综述了国内外应用大数据进行城市时空间行为研究的最新进展,构建了基于大数据应用的城市时空间行为研究方法框架。本文认为,大数据时代城市时空间行为研究方法的变革主要取决于对反映居民时空行为的网络或移动信息设备数据的挖掘、处理及应用,但是还需要进一步推动相关学科间的交叉与融合,加强社交网站等网络数据在居民时空行为和城市空间研究中的应用,并指导城市规划编制与管理方法的创新。     

Deep slab subduction and dehydration and their geodynamic consequences: Evidence from seismology and mineral physics

We present new pieces of evidence from seismology and mineral physics for the existence of low-velocity zones in the deep part of the upper mantle wedge and the mantle transition zone that are caused by fluids from the deep subduction and deep dehydration of the Pacific and Philippine Sea slabs under western Pacific and East Asia. The Pacific slab is subducting beneath the Japan Islands and Japan Sea with intermediate-depth and deep earthquakes down to 600 km depth under the East Asia margin, and the slab becomes stagnant in the mantle transition zone under East China. The western edge of the stagnant Pacific slab is roughly coincident with the NE–SW Daxing'Anling-Taihangshan gravity lineament located west of Beijing, approximately 2000 km away from the Japan Trench. The upper mantle above the stagnant slab under East Asia forms a big mantle wedge (BMW). Corner flow in the BMW and deep slab dehydration may have caused asthenospheric upwelling, lithospheric thinning, continental rift systems, and intraplate volcanism in Northeast Asia. The Philippine Sea slab has subducted down to the mantle transition zone depth under Western Japan and Ryukyu back-arc, though the seismicity within the slab occurs only down to 200–300 km depths. Combining with the corner flow in the mantle wedge, deep dehydration of the subducting Pacific slab has affected the morphology of the subducting Philippine Sea slab and its seismicity under Southwest Japan. Slow anomalies are also found in the mantle under the subducting Pacific slab, which may represent small mantle plumes, or hot upwelling associated with the deep slab subduction. Slab dehydration may also take place after a continental plate subducts into the mantle.     

黑龙江争光金矿水文地质特征浅析

争光金矿床是黑龙江省近年来在其西北部地区发现的一个中(大)型的热液-构造蚀变岩型金矿床。文章论述了争光金矿床岩石赋水特征及其地下水补径排条件,认为采用"大井"法计算露采场基岩裂隙水水量是适宜的,其水文地质参数确定合理。     

GIS基础软件技术体系发展及展望

地理信息系统作为IT系统的重要组成部分,其技术的每一次进步都与最新IT技术的兴起息息相关。随着云计算、大数据、人工智能等技术的发展与应用,如今GIS基础软件已经形成五大技术体系：大数据GIS技术体系,增加了对空间大数据的存储管理、分析处理以及可视化的能力,丰富了空间数据的内涵;人工智能GIS技术体系,GIS通过结合人工智能相关算法,增强了GIS模型的分析预测能力,同时二者之间相互赋能,在增强GIS能力的同时,也让人工智能具备空间分析和可视化能力,拓展了其应用范围;新一代三维GIS技术体系,实现了二三维GIS一体化和多源异构数据的融合,推动了三维GIS从室外走向室内,从宏观走向微观;分布式GIS技术体系,突破了数据类型和容量的限制,数量级提升了GIS软件的性能,让高可用和高可信GIS应用成为可能;跨平台GIS技术体系,使得GIS软件可运行于不同类型的CPU架构和操作系统,满足日益丰富的多终端应用需求。五大技术相辅相成,进一步拓展了GIS基础软件的能力和应用场景。本文以SuperMap GIS为例,详细介绍了GIS五大技术体系的具体内容,阐述了每项技术的难点与创新点,并用光环曲线对五大技术体系的发展阶段进行了划分,探讨了未来GIS技术的发展趋势。