From Paleogeographic maps to Evolving Deep-time Digital Earth models

Major advances in computational power,as well as community modelling workflows and an improvement in data availability,has revolutionized Earth sciences over the last decade.Geological data has been synthesized into flexible and open access plate tectonic and paleogeographic reconstructions using the open-source and cross-platform GPlates(www.gplates.org)software since 2008(Muller et al.,2018;Muller et al.,2008).

Review on status of groundwater database and application prospect in deep-time digital earth plan

Groundwater is an important water resource.The total amount of active groundwater in a hydrological cycle is about 3.5 times that of the total amount of surface water.The information in the deep groundwater records the material exchange and dynamics in the earth’s evolution,which is an important aspect of the Deep-Time Digital Earth(DDE)plan.In recent years,scientists have discussed the distribution of transboundary aquifers and the environmental significance of groundwater resources through groundwater databases established by international organizations,such as the Global Groundwater Information System and the chronicles consortium,and national institutes,such as national geological surveys.The application of the groundwater database in the DDE plan,however,has been limited by the management,interactivity,and monitoring method of the groundwater data.The ability to further integrate data that are private and scattered across research institutions and individuals,while establishing an open,unified,and shared groundwater data platform,is essential to enhance our understanding of groundwater,ranging from shallow to deep water,which is a goal of the DDE plan.In this study,we introduced the current situation of groundwater database operations in domestic and international research and provided frontier research with groundwater big data.Considering the related objectives of the DDE plan and the limitations of existing groundwater databases,we proposed an improvement plan and new prospects for applying groundwater databases in the research of the deep earth.

“Digital earth” in support of an online oceanic educational public service and popularization

According to the initial vision of ＂digital earth＂ （DE）, the public should constitute a significant proportion of its users. However, to date, most of the studies and applications have focused on science, the private sec- tor and government. A DE-supported online oceanic educational public service and popularization system, iOcean, is studied. First, the vision for the public＇s engagement with ＂digital ocean＂ is described： an analysis is presented from four aspects, i.e., the space dimension, the time dimension, the state dimension and its relationship with human beings. Second, the technical framework of iOcean is discussed, including data updating and model computing, the data, the function, and the application layers. Third, two key technolo- gies are studied in detail that will enable the construction of iOcean. More than half a million public viewers have used the current version＇s website. Practical demonstrations show that iOcean can bring virtual oceans to web browsers and desktops and construct a bridge between government departments and the general public.

Digital earth, Virtual Reality and urban seismic disaster simulation

US Vice President Al Gore's vision of Digital Earth applies us with prospects for brand-new ways of solving problems the earth is facing such as seismic disaster. ms paper first briefly introduces the concept of Digital Earth. Then in the context of Digital Earth. the Origin, concept and application of Virtual Reality technology are reviewed. After that we present in detail our preliminary case study--CVR-USD (Computer Virtual Reality for Urban Seismic Disaster Simulation) System which aims to simulate and manage seismic disaster through integrating RS, GIS and VR technologies. For this system, we've built USD subsystem, developed SMVR software to implement CVR. and also developed a Spatial Dare Analysis Package to handle spatial data related to earthquake disaster.

Efficient and reliable road modeling for digital maps based on cardinal spline

In order to realize an optimal balance between the efficiency and reliability requirements ofroad models,a road modeling method for digital maps based on cardinal spline is studied.First,the cardinal spline is chosen to establish an initial road model,which is specified by a series of control points and tension parameters.Then,in view of the initial road model,a gradual optimization algorithm,which can determine the reasonable control points and optimal tension parameters according to the degree of the change of road curvature,is proposed to determine the final road model.Finally,the proposed road modeling method is verified a d evaluated through experiments,and it is compared with the conventional method for digital maps based on the B-spline.The results show that the proposed method can resize a neaoptimal balance between the efficiency and reliability requirements.Compared with the conventional method based on the B-spline,this method occupies less data storage and achieves higher accuracy.

Design of Conceptual Model in Digital Map Database

The components of map information are analyzed theoretically in this paper,and the map information includes mainly the spatial information,attributive information and temporal characteristics information.Then the digital map entity is defined according to construction characteristics of the map information.Finally,on the basis of the analyses of the construction characteristics of digital map entity and present conceptual model of digital map database,an abstracted conceptual model of digital map database is presented.And the Normal Form theory of relational database is discussed particularly.

Modeling the special intersections for enhanced digital map

A new lane-level road modeling method based on cardinal spline is proposed for the special intersections which are covered by vegetation or artificial landscape in their central regions.First,cardinal spline curves are used to fit the virtual lanes inside special intersections,and an initial road model is established using a series of control points and tension parameters.Then,the progressive optimization algorithm is proposed to determine the final road model based on the initial model.The algorithm determines reasonable control points and optimal tension parameters according to the degree of road curvature changes,so as to achieve a balance between the efficiency and reliability of the road model.Finally,the proposed intersection model is verified and evaluated through experiments.The results show that this method can effectively describe the lane-level topological relationship and geometric details of this kind of special intersection where the central area is covered by vegetation or artificial landscape,and can achieve a good balance between the efficiency and reliability of the road model.

The digital mapping of satellite images under no ground control and the distribution of landform, blue ice and meteorites in the Grove Mountains, Antarctica

The colorful satellite image maps with the scale of 1∶100000 were made by processing the parameters-on-satellite under the condition of no data of field surveying. The purpose is to ensure the smooth performance of the choice of expedition route, navigation and research task before the Chinese National Antarctic Research Expedition (CHINARE) first made researches on the Grove Mountains. Moreover, on the basis of the visual interpretation of the satellite image, we preliminarily analyze and discuss the relief and landform, blue ice and meteorite distribution characteristics in the Grove Mountains.

Updated Digital Map of Mafic Dyke Swarms and Large Igneous Provinces in Western Australia

Since 1894,the Geological Survey of Western Australia(GSWA)has released 14 versions of the‘Geological Map of Western Australia’.The latest in this series,published in December 2015,is the first bedrock geology map

Digital Earth在防震减灾工作中的应用——Google Earth为例

美国前副总统戈尔在1998年提出了Digital Earth的概念,本文对Digital Earth在防震减灾工作中的应用做了初步探索,对Digital Earth的主要软件——Google Earth做了介绍,并对其在防震减灾工作中的应用做了详细论述。介绍了Google Earth结合震害快速评估,构造研究、野外地震地质调查的具体应用。Digital Earth在不断发展,在我们的工作、生活中发挥了巨大作用,防震减灾工作中Digital Earth的应用才刚刚开始,可以肯定,Digital Earth作为当今科技制高点,将会使传统防震减灾工作的技术方式等产生根本性的改变。

基于Digital Map的校园三维景观建模

创建校园三维景观模型对信息化校园管理具有重大意义。本文结合内蒙古科技大学三维景观模型制作的需求与实际情况,制定了在现有仪器限制、数据获取困难以及人力缺乏条件下,快速、高效地制作校园三维景观模型的方案。在创建模型的过程中综合使用了两种建模技术,多种纹理映射方式,得到一种高效的、快速建立三维景观模型的方法。并根据建立的三维模型创建了三维漫游动画,并在Google Earth中获取多种属性信息。

Digital mapping of soil salinization based on Sentinel-1 and Sentinel-2 data combined with machine learning algorithms

Soil salinization is one of the most important causes of land degradation and desertification,especially in arid and semi-arid areas.The dynamic monitoring of soil salinization is of great significance to land management,agricultural activities,water quality,and sustainable development.The remote sensing images taken by the synthetic aperture radar(SAR)Sentinel-1 and the multispectral satellite Sentinel-2 with high resolution and short revisit period have the potential to monitor the spatial distribution of soil attribute information on a large area;however,there are limited studies on the combination of Sentinel-1 and Sentinel-2 for digital mapping of soil salinization.Therefore,in this study,we used topography indices derived from digital elevation model(DEM),SAR indices generated by Sentinel-1,and vegetation indices generated by Sentinel-2 to map soil salinization in the Ogan-Kuqa River Oasis located in the central and northern Tarim Basin in Xinjiang of China,and evaluated the potential of multi-source sensors to predict soil salinity.Using the soil electrical conductivity(EC)values of 70 ground sampling sites as the target variable and the optimal environmental factors as the predictive variable,we constructed three soil salinity inversion models based on classification and regression tree(CART),random forest(RF),and extreme gradient boosting(XGBoost).Then,we evaluated the prediction ability of different models through the five-fold cross validation.The prediction accuracy of XGBoost model is better than those of CART and RF,and soil salinity predicted by the three models has similar spatial distribution characteristics.Compared with the combination of topography indices and vegetation indices,the addition of SAR indices effectively improves the prediction accuracy of the model.In general,the method of soil salinity prediction based on multi-source sensor combination is better than that based on a single sensor.In addition,SAR indices,vegetation indices,and topography indices are all effective variables for soil salinity prediction.Weighted Difference Vegetation Index(WDVI)is designated as the most important variable in these variables,followed by DEM.The results showed that the high-resolution radar Sentinel-1 and multispectral Sentinel-2 have the potential to develop soil salinity prediction model.

The Application Study of “Digital Earth” in Geological Heritage Resources and Constructing Geological Parks

"Digital Earth"is one of integrated scientific technology based on development of information technology and modern space telemetry,and it possesses some special features such as application of great amount of geography data,which can describe the Earth in three dimensions and with higher resolution,i.e."virtual earth":the ordinary user also can readily obtain some information through certain means.Visualization and virtual reality are one

Study of“Digital Earth”and“Earth System Science”

"Digital Earth"is a leap in the process of mankind learning about the Earth after the great geographical discovery of Copernicus,Galileoi’s heliocentric theory.Currently a series of problems like nature resources,environment,zoology and disaster have threatened the survival and development of mankind. In recent years,long term and solid

Digital mapping in agriculture and environment

Global demand for soil data and information for maintaining and improving agricultural productivity and environmental health is soaring.The accurate and rapid digital maps of soil characteristics are of key importance for evaluation of soil fertility,precision management of crop inputs,estimation of carbon stocks,and modeling ecological responses as well as environmental threats.

The Digital Mapping of Ukrainian Soils on the Base of High Resolution Space Images

The first Ukrainian using experience of multispectral space scanning for digital soil mapping is described in this paper. Methodical approaches for detailed soil observation of Ukrainian forest regions are elaborated based on modem mapping principles. For the first time in Ukraine, digital soil maps based on GIS （geographic information system） were obtained for individual farms. In GIS based on space images and digital relief models, the medium-scale and large-scale soil maps were created by geo-statistical methods. According to elaborated methods, modem digital soil mapping should provide all combined works： remote sensing and traditional soil observations. The modem digital soil mapping should be based just on quantitative principles： on remote sensing data, geomorphologic field parameters, and chemical analyses. The methodological approaches, which were used for the first time in Ukraine during digital soil mapping by remote sensing methods, are described in this paper.

Hexagonal connectivity maps for Digital Earth

Geospatial data are gathered through a variety of different methods.The integration and handling of such datasets within a Digital Earth framework are very important in many aspects of science and engineering.One means of addressing these tasks is to use a Discrete Global Grid System and map points of the Earth’s surface to cells.An indexing mechanism is needed to access the data and handle data queries within these cells.In this paper,we present a general hierarchical indexing mechanism for hexagonal cells resulting from the refinement of triangular spherical polyhedra representing the Earth.In this work,we establish a 2D hexagonal coordinate system and diamond-based hierarchies for hexagonal cells that enables efficient determination of hierarchical relationships for various hexagonal refinements and demonstrate its usefulness in Digital Earth frameworks.

Has OpenStreetMap a role in Digital Earth applications?

Volunteered geographic information(VGI),as a special subset of crowdsourcing,has provoked interest from many scientific disciplines and industry in the past few years.OpenStreetMap(OSM)is the most famous and well supported example of a VGI project on the Internet today.As a technology,Digital Earth(DE)offers immediate access to enormous quantities of data and information,referenced by locations on the surface of the planet.One of DE’s goals is to make global spatial information ubiquitously available as an essential component of democracy.OSM’s mission is well positioned within this goal where OSM aims to create a freely available editable map database of the world.This paper explores the characteristics of the collaborative,crowd-based,editing of spatial data in OSM and the crowd itself.We provide some conclusions on how OSM can be best integrated into the fabric of DE.

Digital Earth in support of global change research

The Digital Earth concept as originally proposed by former US Vice president Al Gore is now well established and widely adopted internationally.Similarly,many researchers world-wide are studying the causes,effects and impacts of Global Change.The authors commence by describing a five-step approach to the development of Digital Earth technologies.This is followed by a detailed account of Digital Earth research and developments in China.The authors then present the research results of Global Change studies carried out in China,based on the Digital Earth approach.These research results are based on a classification of global change regions.This covers the following global change situations:Forest and grassland fires in Northern China,temperate region desertification and dust storms,underground coal fires,deforestation and carbon sequestration,protection and utilisation of wetlands,Avian Influenza and the spread of diseases,Tibet Plateau uplift and sub-tropical monsoon climate region,and sea-level rise.The research results show that the environment does not behave in a way easily understood by the traditional disciplinary approach.Although man is clearly a contributing factor to certain Global Change aspects,such as underground coal fires,desertification,land use changes etc.,many of the aspects of Global Change are naturally occurring phenomena which have been changing over centuries,and will continue to do so,no matter what actions we undertake to reverse these processes.Hence,in their conclusions,the authors propose that the communities involved in Digital Earth modelling and in Global Change research co-operate closer to overcome the limitations inherent in the current‘conventional’scientific approach,where scientists have very much stayed within their respective scientific boundaries.Such an integrated approach will enable us to build the next level of scientific infrastructure required to understand and predict naturally occurring environmental changes,as well as that of coupled humanenvironmental systems.

The role of GIS in Digital Earth education

A growing number of educators worldwide have become convinced that geotechnologies
including geographic information systems(GIS),global positioning systems(GPS),and remote sensing
are key technologies to prepare students to be tomorrow’s decision makers.Grappling with local,regional,and global issues of the 21st century requires people who think spatially and who can use geotechnologies.Some educators teach geotechnologies as a discipline,emphasising skills.Other educators use geotechnologies as a tool to teach content,such as geography,history,environmental studies,Earth Science,biology,mathematics,economics and other disciplines.Issues such as traffic,population growth,urban sprawl,energy,water,crime,human health,biodiversity and sustainable agriculture are growing in complexity,exist at every scale and increasingly affect people’s everyday lives.Each of these issues has a spatial component.Drivers for geotechnology education include educational content standards,constructivism,the school-to-career movement,active learning,citizenship education,authentic practice and assessment,interdisciplinary education,community connections and a sustained,increasing demand for GIS professionals.Digital Earth is an ideal framework for contextualising domains of inquiry.The Digital Earth community can have a significant impact on the growth of geotechnologies in education,and conversely,the growth of geotechnologies in education and society can foster the forward movement of Earth systems concepts.