Digital Earth Platform Research Articles

A database of detrital zircon U–Pb ages and Hf isotopic compositions from the Tarim, West Kunlun, Pamir, Tajik and Tianshuihai terranes

AbstractWith the development of detrital zircon U–Pb ages and Hf isotope analysis as conventional sedimentological research methods, a large number of studies have been conducted in the Tarim, West Kunlun, Tajik, Pamir and Tianshuihai regions and abundant data have been accumulated. Summarizing these data to characterize sedimentary units and source regions is more important than local studies of specific geological epochs; therefore, we compiled a database of detrital zircon U–Pb ages and Hf isotope analyses from the Tarim, West Kunlun, Pamir, Tajik and Tianshuihai terranes. The database contains data from 90 papers, including 35,281 individual U–Pb ages and 4,181 Hf isotope analyses. The database records the literature source, petrologic sample information, regional geological information, geographic coordinates and analytical parameters for each data point in as much detail as possible to allow readers to review, process, analyse and use the data. The database relies on the Deep‐time Digital Earth (DDE) platform and uses an open database update system to enable sharing and collaborative building. We encourage other researchers to contribute relevant published data to facilitate wider use.

Bibliometric Analysis of OGC Specifications between 1994 and 2020 Based on Web of Science (WoS)

The Open Geospatial Consortium (OGC) is an international non-profit standards organization. Established in 1994, OGC aims to make geospatial information and services FAIR-Findable, Accessible, Interoperable, and Reusable. OGC specifications have greatly facilitated interoperability among software, hardware, data, and users in the GIS field. This study collected publications related to OGC specifications from the Web of Science (WoS database) between 1994 to 2020 and conducted a literature analysis using Derwent Data Analyzer and VosViewer, finding that OGC specifications have been widely applied in academic fields. The most productive organizations were Wuhan University and George Mason University; the most common keywords were interoperability, data, and web service. Since 2018, the emerging keywords that have attracted much attention from researchers were 3D city models, 3D modeling, and smart cities. To make geospatial data FAIR, the OGC specifications SWE and WMS served more for “Findable”, SWE contributed more to “Accessible”, WPS and WCS served more for “Interoperable”, and WPS, XML schemas, WFS, and WMS served more for “Reusable”. The OGC specification also serves data and web services for large-scale infrastructure such as the Digital Earth Platform of the Chinese Academy of Sciences.

Mapping Chemical Earth Program: Progress and challenge

There is a critical need to establish a global geochemical observation network to provide data for monitoring the chemical changes of the Earths near-surface environment. The International Centre on Global-scale Geochemistry, under auspices of UNESCO and Government of China, has initiated an International Scientific Cooperation Project called Mapping Chemical Earth. The project focuses on the establishment of Global Geochemical Observatory Network for documenting baselines and changes of nearly all natural chemical elements in the Earths surface and creating a digital Chemical Earth platform allowing anyone to access vast amounts of geochemical data through the Internet. A total area of about 37 million km2, nearly accounting for 27% of the global land, has been covered by global-/continental-scale sampling. Comparing the data of China, the US, Europe and Australia, the percentage of sites with toxic metals exceeding the risk limits of soil pollution according to “Environmental Quality Standard for Soil of China (GB 15618-1995)” to the total sample sites is 30.9%, 17.1%, 23.5% and 10.9% in Europe, China, USA, and Australia respectively. Comparing the China datasets of 15 years interval sampling between 1994, 1995 and in 2008–2012, toxic metals of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn, particularly Cd at top soils significantly increase from 1990s to 2010s. The proportion of top soil samples exceeding the China Standard risk limit of 0.2 mg/kg Cd increases from 12.2% to 24.9%. The facts show that chemical changes of toxic metals induced by human activities can be well observed using catchment sediment sampling.

Dynamic 3D Simulation of Flood Risk Based on the Integration of Spatio-Temporal GIS and Hydrodynamic Models

Dynamic visual simulation of flood risk is crucial for scientific and intelligent emergency management of flood disasters, in which data quality, availability, visualization, and interoperability are important. Here, a seamless integration of a spatio-temporal Geographic Information System (GIS) with one-dimensional (1D) and two-dimensional (2D) hydrodynamic models is achieved for data flow, calculation processes, operation flow, and system functions. Oblique photography-based three-dimensional (3D) modeling technology is used to quickly build a 3D model of the study area (including the hydraulic engineering facilities). A multisource spatio-temporal data platform for dynamically simulating flood risk was built based on the digital earth platform. Using the spatio-temporal computation framework, a dynamic visual simulation and decision support system for flood risk management was developed for the Xiashan Reservoir. The integration method proposed here was verified using flood simulation calculations, dynamic visual simulations, and downstream river channel and dam-break flood simulations. The results show that the proposed methods greatly improve the efficiency of flood risk simulation and decision support. The methods and system put forward in this study can be applied to flood risk simulations and practical management.

WebGL-based Visualization Method for Large-scale 3D Scene

For the requirements of transmission and real-time visualization of large-scale threedimensional scenes in the Web environment, this paper adopts the three-dimensional model data structure 3DTiles which is suitable for data sharing and network switching, and analyzes the advantages of building three-dimensional scenes based on 3D Tiles. Meanwhile, through the skipping loading of the hierarchical detail model, the model loading time, network requests and memory consumption are reduced, while the scene data drawing efficiency is improved. Based on these theories and technologies, this paper designs and builds a three-dimensional digital earth platform based on WebGL. Experimental results show that this platform can smoothly implement the drawing of large-scale 3D scenes, and achieve the visualization effects and good visual experience.

SPATIOTEMPORAL VISUALIZATION OF TIME-SERIES SATELLITE-DERIVED CO2 FLUX DATA USING VOLUME RENDERING AND GPU-BASED INTERPOLATION ON A CLOUD-DRIVEN DIGITAL EARTH

Abstract. The ocean carbon cycle has a significant influence on global climate, and is commonly evaluated using time-series satellite-derived CO2 flux data. Location-aware and globe-based visualization is an important technique for analyzing and presenting the evolution of climate change. To achieve realistic simulation of the spatiotemporal dynamics of ocean carbon, a cloud-driven digital earth platform is developed to support the interactive analysis and display of multi-geospatial data, and an original visualization method based on our digital earth is proposed to demonstrate the spatiotemporal variations of carbon sinks and sources using time-series satellite data. Specifically, a volume rendering technique using half-angle slicing and particle system is implemented to dynamically display the released or absorbed CO2 gas. To enable location-aware visualization within the virtual globe, we present a 3D particlemapping algorithm to render particle-slicing textures onto geospace. In addition, a GPU-based interpolation framework using CUDA during real-time rendering is designed to obtain smooth effects in both spatial and temporal dimensions. To demonstrate the capabilities of the proposed method, a series of satellite data is applied to simulate the air-sea carbon cycle in the China Sea. The results show that the suggested strategies provide realistic simulation effects and acceptable interactive performance on the digital earth.

A digital earth platform for sustainability

ABSTRACTBased on the experience of the International Society for Digital Earth (ISDE), this paper describes some challenges foreseen in order to develop a Digital Earth platform that can support the implementation of the Sustainable Development Goals. The use of ready-to-use derived geospatial information is essential. Future Earth’s methodology of ‘co-design’ aims to bring together natural, social scientists and decision makers to plan and carry out research for sustainability. Sustainability implies transdisciplinary research, but in order for scientists of different disciplines to work together, they will need to be able to share, access and use common data. This is by far not simple! While the good will to share data might exist, the associated technological, ethical and privacy issues are difficult to solve. An adequate e-infrastructure will be required. ISDE could consider to use the SDGs is the basis to develop the desired Digital Earth platform. This paper, by no means, covers everything for a Digital Earth platform, it aims to trigger research discussions and to have a good view about a starting point.

World Heritage Data Management and Visualization Based on WikiGlobe

Heritage includes the legacy in the past, what we live with today, and what we pass on to future generations. Our cultural and natural heritage are both irreplaceable sources of life and inspiration. There are many introductions about World Heritage on the Internet, especially the official website of United Nations Educational Scientific and cultural organization (UNESCO), which provides the authoritative and comprehensive data of world heritage. It is usually the most popular platform to obtain world heritage information. Combining world heritage with the WikiGlobe (a Digital Earth platform), a scene mode was set from a global perspective with more vivid presentation. This was one of the innovation points of this research. Compared with the traditional 2D display, WikiGlobe has a significant 3D visual effect and various visual tools. Based on WikiGlobe, this research focused on the characteristics of data, organization management and approaches of visualization and realized multi-information navigation and interaction mechanism. In addition, a dynamic mechanism of data maintenance has been established to achieve effective management and visualization of heritage data.

The architecture for data, security and application in Digital Earth platform

Digital Earth platform is an application, service and decision support system, which integrates geo-spatial data acquisition, transmission, storage, processing, analysis, statistics and visualization. It realizes comprehensive management and widely application of different kinds of huge earth data under the geo-spatial framework and in a open environment. It should consider the continues growing of data and applications, as well as data security. According to the issues of how to safely use spatial data in Digital Earth platform, an architecture for data,security and application in Digital Earth platform was proposed in this paper. We call this architecture DOA(DOSA). In the digital earth platform on its goal is the Trusted Data. DOA(DOSA) and Trusted Data can provide data management, security grantee, application supporting for Digital Earth platform.

Design and realization of RS application system for earthquake emergency based on digital earth

The current RS-based earthquake emergency system is mainly based on stand-alone software which cannot meet the requirements of massive remote sensing data and parallel seismic damage information extraction after a devastating earthquake. Taking Shaanxi Province as an example, this paper explored firstly the network-based working mode of seismic damage information extraction and data management strategy for multi-user cooperative operation based on analysing work flow of the RS application to earthquake emergency. Then, using WorldWind java SDK, the RS application system for earthquake emergency based on digital earth platform was brought out in CS architecture. Finally, spatial data tables of classification and grade of seismic damage were designed and the system was developed. This system realized functions including 3D display, management of seismic RS image and GIS data obtained before and after earthquake for different user levels and cooperative extraction and publish of such seismic information as building damage, traffic damage and seismo-geological disasters caused by earthquake in real time. Some application to earthquake cases such as 2014 Ms6.5 Ludian earthquake show that this system can improve the efficiency of seismic damage information interpretation and data sharing, and provide import disaster information for decision making of earthquake emergency rescue and disaster relief.

Design of 3D Digital Earth Resource Mapping System

In order to organize and manage the heterogeneous and volume geographic information resources efficiently for a 3D Digital Earth platform, this paper designs the Resource Mapping System (RMS) and implements it in the Henu Digit Earth (HDE) platform. And the framework and key technologies of the RMS are also discussed.

The Research of Petroleum Enterprise Information System Architecture Based on the G/S Model

This paper explains the petroleum engineering technologies of petroleum enterprise supported by G/S model, which combine process of exploring, developing, and transporting of petroleum enterprise, these key technologies with spatial information technology supported by Digital Earth Platform, resulting in the improvement of the scientificity, accuracy, and rationality of the petroleum engineering technologies and the reduction of the cost and the increase of the benefits.

The use of high-performance and high-throughput computing for the fertilization of digital earth and global change studies

The study of global climate change seeks to understand: (1) the components of the Earth's varying environmental system, with a particular focus on climate; (2) how these components interact to determine present conditions; (3) the factors driving these components; (4) the history of global change and the projection of future change; and (5) how knowledge about global environmental variability and change can be applied to present-day and future decision-making. This paper addresses the use of high-performance computing and high-throughput computing for a global change study on the Digital Earth (DE) platform. Two aspects of the use of high-performance computing (HPC)/high-throughput computing (HTC) on the DE platform are the processing of data from all sources, especially Earth observation data, and the simulation of global change models. The HPC/HTC is an essential and efficient tool for the processing of vast amounts of global data, especially Earth observation data. The current trend involves running complex global climate models using potentially millions of personal computers to achieve better climate change predictions than would ever be possible using the supercomputers currently available to scientists.

A Novel Network Service Mode of Geospatial Information and its Prototype System

This paper proposes a novel digital earth platform framework, which is a application, service and decision-making support systems of geospatial data acquisition, storage, transmission, conversion, processing, analysis, retrieval, expression and output as a unified body, the core of which is to deal with geospatial data for spatial geographic information network service Geo-Browser/Geospatial Information Server (G/S) mode and Hyper Geographic Markup Language (HGML). Depth understanding and analysis of platform architecture, this paper realizes of digital earth platform prototype – U-Star based on the geospatial information network service G/S mode, the platform has the merits of C/S mode that full use of client resources, efficient to deal with the client data, as well as the advantages of B/S mode that the unified client and convenient to access network. This platform is a new server which can cope with massive geospatial information and a solution which can provide efficient service. It has already been applied into many fields, such as the digital tourism service system, the time sequence analysis of Wenchuan Earthquake, the real-time video monitoring based on the digital earth platform and the intelligent processing and exhibition of remote sensing data. The result indicates that the perfection of space, time and complexion of the geospatial information network accessing will effectively improve the quality and efficiency of the shared data, which has very important theoretical significance and bright prospect of application.