Application of Web-GIS and Geovisual Analytics to Monitoring of Seabed Evolution in South Baltic Sea Coastal Areas

Regular surveys of coastal zone seabed deliver important information about geomorphologic processes such as silting of waterways. The recent introduction of the Sentinel series of sensors has allowed for the use of satellite sensing for shallow bathymetry morphology monitoring. In this context, this article presents a dedicated Geographic Information System for Baltic Sea shallow water depth monitoring on the basis of Sentinel-2 imagery. The system employs Geovisual Analytics for differential analysis of bathymetry changes as well as monitoring the visibility of known wrecks in the coastal waters of Southern Baltic Sea. Results are verified with regard to known changes in shallow water bathymetry between 28 June 2015 and 3 March 2017.     

Direct observation of complex Tóthian groundwater flow systems in the laboratory

Based on the theory of gravity‐driven groundwater flow systems, we have developed a complex Flow System Sand‐Box Model (FSM). It enables the visual observations of the development and characteristics and temporal evolution of complex Tóthian flow systems in the laboratory. The configuration of the regional, intermediate and local flow systems can be controlled and observed; hydraulic head, flow direction and travel time can be measured; and the scale and shape of the sub‐flow systems as well as the path lines and flow lines can be observed directly. The experiments demonstrate the Tóthian flow systems in a small basin with multiple sources and sinks. Greater local topographic (water table) undulation will lead to larger local flow systems. Greater regional and less local topographic undulation will enhance the development of intermediate and regional flow systems. In homogeneous media, increasing fluid‐potential differences between source and sink increase the spatial scale of the generated flow systems. The FSM is a useful teaching aid and experimental device to study and develop an intuitive insight into gravity‐driven groundwater flow systems. It helps to visualize and understand the hydraulic properties and controlling factors of Tóthian flow systems and may be used to study problems related to the chemical and temperature characteristics of the flow systems as well. Copyright © 2010 John Wiley & Sons, Ltd.     

Areal extent of the 1988 flood in Bangladesh: How much did the satellite imagery show?

This paper presents the methods and results of visual interpretation of satellite imagery for estimating areal extent of the 1988 flood in Bangladesh. The main limitation of this method was that cloud-free images were not available for the peak flood period in the first week of September. Relatively cloud-free images on three selected dates in the last three weeks of September showed that areas of inundation on those dates ranged from 44000 to 60000 km² ± 5% (31 to 42% of Bangladesh). The Government of Bangladesh official estimates of the areal extent of flooding were tentative in nature, since these were based on a choropleth map of relative proportions (percentages) of flooding in different parts of the country. The official estimate of the maximum extent of flooding was 82000 km² (57% of Bangladesh), i.e. 15 to 26% larger than the area shown on satellite imagery. The actual extent of flooding was certainly larger than the estimates from satellite imagery but, perhaps, smaller than the official estimates, since a reduction of 15 to 26% of flood area in one to three weeks seemed unlikely. An alternative method of mapping flood-affected areas by using newspaper-interpreted data was attempted, but the method had limited values because of reporting bias.     

视景地形仿真及其应用

本文主要讨论了视景地形仿真的特点、数据基础及其实现的整个过程，列举了视景地形仿真在军事上和其它领域的应用实例。实验表明，本文所介绍的视景地形仿真过程简单而容易实现，仿真的地形景观具有良好的视觉效果。     

微机双道原子荧光光度计测控系统设计

该系统采用串口通信方式完成嵌入式单片机系统^[1]和计算机之间通信，通过测量待测溶液和标样的荧光强度来计算待测液中某痕量元素的含量，该系统具有图形化友好菜单操作、可视化的曲线分析和数据处理等特点。     

An IEEE value loop of human-technology collaboration in geospatial information science

ABSTRACT

Geosensing and social sensing as two digitalization mainstreams in big data era are increasingly converging toward an integrated system for the creation of semantically enriched digital Earth. Along with the rapid developments of AI technologies, this convergence has inevitably brought about a number of transformations. On the one hand, value-adding chains from raw data to products and services are becoming value-adding loops composed of four successive stages – Informing, Enabling, Engaging and Empowering (IEEE). Each stage is a dynamic loop for itself. On the other hand, the “human versus technology” relationship is upgraded toward a game-changing “human and technology” collaboration. The information loop is essentially shaped by the omnipresent reciprocity between humans and technologies as equal partners, co-learners and co-creators of new values.

The paper gives an analytical review on the mutually changing roles and responsibilities of humans and technologies in the individual stages of the IEEE loop, with the aim to promote a holistic understanding of the state of the art of geospatial information science. Meanwhile, the author elicits a number of challenges facing the interwoven human-technology collaboration. The transformation to a growth mind-set may take time to realize and consolidate. Research works on large-scale semantic data integration are just in the beginning. User experiences of geovisual analytic approaches are far from being systematically studied. Finally, the ethical concerns for the handling of semantically enriched digital Earth cover not only the sensitive issues related to privacy violation, copyright infringement, abuse, etc. but also the questions of how to make technologies as controllable and understandable as possible for humans and how to keep the technological ethos within its constructive sphere of societal influence.     

Big spatial data for urban and environmental sustainability

ABSTRACT

Eighty percent of big data are associated with spatial information, and thus are Big Spatial Data (BSD). BSD provides new and great opportunities to rework problems in urban and environmental sustainability with advanced BSD analytics. To fully leverage the advantages of BSD, it is integrated with conventional data (e.g. remote sensing images) and improved methods are developed. This paper introduces four case studies: (1) Detection of polycentric urban structures; (2) Evaluation of urban vibrancy; (3) Estimation of population exposure to PM2.5; and (4) Urban land-use classification via deep learning. The results provide evidence that integrated methods can harness the advantages of both traditional data and BSD. Meanwhile, they can also improve the effectiveness of big data itself. Finally, this study makes three key recommendations for the development of BSD with regards to data fusion, data and predicting analytics, and theoretical modeling.     

电子地形图符号体系的研究

随着数字制图技术的发展,电子地图的应用日益增多,为保证地理信息感知和认知的一致性与准确性,达到信息与资源共享,电子地形图符号的规范化、标准化势在必行。文中针对此种需求介绍了电子地形图符号体系和符号标准化的研究现状,分析了电子地形图符号体系中存在的主要问题,详细阐述了电子地形图符号体系构建的基本原则、内容以及体系结构,并且结合示例进行了说明,为电子地形图符号体系的研究提供了一些思路。     

战场地理空间信息可视化系统设计与研究

对当前流行的3DGIS系统进行了介绍,并研究提出了采用面向对象的方法来表达3D场景中的空间数据,基于栅格金字塔模型来组织和管理地形数据,基于视点相关的地形LoD方法实现了大范围漫游,基于参数化3D建模方法和矢量地物LoD来实现地物数据的建模和可视化的方法,设计和构建西北地区战场地理空间信息可视化系统(3DMGIS)。     

Models of α Centauri A and B with and without seismic constraints: time dependence of the mixing-length parameter

The α Centauri (α Cen) binary system is a well-known stellar system with very accurate observational constraints on the structure of its component stars. In addition to the classical non-seismic constraints, there are also seismic constraints for the interior models of α Cen A and B. These two types of constraint give very different values for the age of the system. While we obtain 8.9 Gyr for the age of the system from the non-seismic constraints, the seismic constraints imply that the age is about 5.6–5.9 Gyr. There may be observational or theoretical reasons for this discrepancy, which can be found by careful consideration of similar stars. The α Cen binary system, with its solar-type components, is also suitable for testing the stellar mass dependence of the mixing-length parameter for convection derived from the binaries of Hyades. The values of the mixing-length parameter for α Cen A and B are 2.10 and 1.90 for the non-seismic constraints. If we prioritize the seismic constraints, we obtain 1.64 and 1.91 for α Cen A and B, respectively. By taking into account these two contrasting cases for stellar mass dependence of the mixing-length parameter, we derive two expressions for its time dependence, which are also compatible with the mass dependence of the mixing-length parameter derived from the Hyades stars. For assessment, these expressions should be tested in other stellar systems and clusters.