Spatiotemporal data fusion technologies have been widely used for land surface phenology(LSP)monitoring since it is a low-cost solution to obtain fine-resolution satellite time series.However,the reliability of fused ...Spatiotemporal data fusion technologies have been widely used for land surface phenology(LSP)monitoring since it is a low-cost solution to obtain fine-resolution satellite time series.However,the reliability of fused images is largely affected by land surface heterogeneity and input data.It is unclear whether data fusion can really benefit LSP studies at fine scales.To explore this research question,this study designed a sophisticated simulation experiment to quantify effectiveness of 2 representative data fusion algorithms,namely,pair-based Spatial and Temporal Adaptive Reflectance Fusion Model(STARFM)and time series-based Spatiotemporal fusion method to Simultaneously generate Full-length normalized difference vegetation Index Time series(SSFIT)by fusing Landsat and Moderate Resolution Imaging Spectroradiometer(MODIS)data in extracting pixel-wise spring phenology(i.e.,the start of the growing season,SOS)and its spatial gradient and temporal variation.Our results reveal that:(a)STARFM can improve the accuracy of pixel-wise SOS by up to 74.47%and temporal variation by up to 59.13%,respectively,compared with only using Landsat images,but it can hardly improve the retrieval of spatial gradient.For SSFIT,the accuracy of pixel-wise SOS,spatial gradient,and temporal variation can be improved by up to 139.20%,26.36%,and 162.30%,respectively;(b)the accuracy improvement introduced by fusion algorithms decreases with the number of available Landsat images per year,and it has a large variation with the same number of available Landsat images,and(c)this large variation is highly related to the temporal distributions of available Landsat images,suggesting that fusion algorithms can improve SOS accuracy only when cloud-free Landsat images cannot capture key vegetation growth period.This study calls for caution with the use of data fusion in LSP studies at fine scales.展开更多
Under the global health crisis of COVID-19,timely,and accurate epi-demic data are important for observation,monitoring,analyzing,modeling,predicting,and mitigating impacts.Viral case data can be jointly analyzed with ...Under the global health crisis of COVID-19,timely,and accurate epi-demic data are important for observation,monitoring,analyzing,modeling,predicting,and mitigating impacts.Viral case data can be jointly analyzed with relevant factors for various applications in the context of the pandemic.Current COVID-19 case data are scattered across a variety of data sources which may consist of low data quality accompanied by inconsistent data structures.To address this short-coming,a multi-scale spatiotemporal data product is proposed as a public repository platform,based on a spatiotemporal cube,and allows the integration of different data sources by adopting various data standards.Within the spatiotemporal cube,a comprehensive data processing workflow gathers disparate COVID-19 epidemic data-sets at the global,national,provincial/state,county,and city levels.This proposed framework is supported by an automatic update with a 2-h frequency and the crowdsourcing validation team to produce and update data on a daily time step.This rapid-response dataset allows the integration of other relevant socio-economic and environ-mental factors for spatiotemporal analysis.The data is available in Harvard Dataverse platform(https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/8HGECN)and GitHub open source repository(https://github.com/stccenter/COVID-19-Data).展开更多
In the research field of spatiotemporal data discovery,how to utilize the semantic characteristics of spatiotemporal datasets is an important topic.This paper presented a content-based recommendation method,and applie...In the research field of spatiotemporal data discovery,how to utilize the semantic characteristics of spatiotemporal datasets is an important topic.This paper presented a content-based recommendation method,and applied Bayesian networks and ontologies into the vocabulary recommendation process for spatiotemporal data discovery.The source data of this research was from the MUDROD(Mining and Utilizing Dataset Relevancy from Oceanographic Datasets)search platform.From the historical search log,major keywords were extracted and organized according to ontologies in a hierarchical structure.Using the search history,the posterior probability between each subclass and their super class in the ontologies was calculated,indicating a recommendation likelihood.We created a Bayesian network model for inference based on ontologies.This model can address the following two objectives:(1)Given one class in the ontology,the model can judge which class has the biggest likelihood to be selected for recommendation.(2)Based on the search history of a user,the Bayesian network model can judge which class has the biggest probability to be recommended.Comparison experimentation with existing system and evaluation experimentation with expert knowledge show that this method is specifically helpful for spatiotemporal data discovery.展开更多
How can we efficiently store and mine dynamically generated dense tensors for modeling the behavior of multidimensional dynamic data?Much of the multidimensional dynamic data in the real world is generated in the form...How can we efficiently store and mine dynamically generated dense tensors for modeling the behavior of multidimensional dynamic data?Much of the multidimensional dynamic data in the real world is generated in the form of time-growing tensors.For example,air quality tensor data consists of multiple sensory values gathered from wide locations for a long time.Such data,accumulated over time,is redundant and consumes a lot ofmemory in its raw form.We need a way to efficiently store dynamically generated tensor data that increase over time and to model their behavior on demand between arbitrary time blocks.To this end,we propose a Block IncrementalDense Tucker Decomposition(BID-Tucker)method for efficient storage and on-demand modeling ofmultidimensional spatiotemporal data.Assuming that tensors come in unit blocks where only the time domain changes,our proposed BID-Tucker first slices the blocks into matrices and decomposes them via singular value decomposition(SVD).The SVDs of the time×space sliced matrices are stored instead of the raw tensor blocks to save space.When modeling from data is required at particular time blocks,the SVDs of corresponding time blocks are retrieved and incremented to be used for Tucker decomposition.The factor matrices and core tensor of the decomposed results can then be used for further data analysis.We compared our proposed BID-Tucker with D-Tucker,which our method extends,and vanilla Tucker decomposition.We show that our BID-Tucker is faster than both D-Tucker and vanilla Tucker decomposition and uses less memory for storage with a comparable reconstruction error.We applied our proposed BID-Tucker to model the spatial and temporal trends of air quality data collected in South Korea from 2018 to 2022.We were able to model the spatial and temporal air quality trends.We were also able to verify unusual events,such as chronic ozone alerts and large fire events.展开更多
Public space as an extension of private living spaces carries the different social life and customs of human settlement.To analyze the spatial distribution characteristics of traditional villages in northern Guangxi b...Public space as an extension of private living spaces carries the different social life and customs of human settlement.To analyze the spatial distribution characteristics of traditional villages in northern Guangxi based on spatial syntax and its influencing factors,this paper analyzed and compared the spatial structure and morphology of traditional villages in northern Guangxi by using the theory of spatial syntax and linguistics as the quantitative analysis method of spatial syntax,and verified the feasibility of expanding the application of spatial syntax,finally,the generality and characteristics of the spatial structure and form of traditional villages in northern Guangxi were put forward.Protection has been implemented.According to the comprehensibility data in this paper,the comprehensibility of the village 1 in northern Guangxi is 0.52,the village 2 is 0.40,the village 3 is 0.35,the village 4 is 0.48,the village 5 is 0.55 and the village 6 is 0.50.It showed that in the selected 6 village samples,except for the 3 ones in northern Guangxi,the local space of the other 3 villages could better perceive the overall space,which also reflected the overall space permeability of most traditional villages in northern Guangxi was good.展开更多
Oceanic dissolved oxygen(DO)in the ocean has an indispensable role on supporting biological respiration,maintaining ecological balance and promoting nutrient cycling.According to existing research,the total DO has dec...Oceanic dissolved oxygen(DO)in the ocean has an indispensable role on supporting biological respiration,maintaining ecological balance and promoting nutrient cycling.According to existing research,the total DO has declined by 2%of the total over the past 50 a,and the tropical Pacific Ocean occupied the largest oxygen minimum zone(OMZ)areas.However,the sparse observation data is limited to understanding the dynamic variation and trend of ocean using traditional interpolation methods.In this study,we applied different machine learning algorithms to fit regression models between measured DO,ocean reanalysis physical variables,and spatiotemporal variables.We demonstrate that extreme gradient boosting(XGBoost)model has the best performance,hereby reconstructing a four-dimensional DO dataset of the tropical Pacific Ocean from 1920 to 2023.The results reveal that XGBoost significantly improves the reconstruction performance in the tropical Pacific Ocean,with a 35.3%reduction in root mean-squared error and a 39.5%decrease in mean absolute error.Additionally,we compare the results with three Coupled Model Intercomparison Project Phase 6(CMIP6)models data to confirm the high accuracy of the 4-dimensional reconstruction.Overall,the OMZ mainly dominates the eastern tropical Pacific Ocean,with a slow expansion.This study used XGBoost to efficiently reconstructing 4-dimensional DO enhancing the understanding of the hypoxic expansion in the tropical Pacific Ocean and we foresee that this approach would be extended to reconstruct more ocean elements.展开更多
Sensor networks provide means to link people with real world by processing data in real time collected from real-world and routing the query results to the right people. Application examples include continuous monitor...Sensor networks provide means to link people with real world by processing data in real time collected from real-world and routing the query results to the right people. Application examples include continuous monitoring of environment, building infrastructures and human health. Many researchers view the sensor networks as databases, and the monitoring tasks are performed as subscriptions, queries, and alert. However, this point is not precise. First, databases can only deal with well-formed data types, with well-defined schema for their interpretation, while the raw data collected by the sensor networks, in most cases, do not fit to this requirement. Second, sensor networks have to deal with very dynamic targets, environment and resources, while databases are more static. In order to fill this gap between sensor networks and databases, we propose a novel approach, referred to as 'spatiotemporal data stream segmentation', or 'stream segmentation' for short, to address the dynamic nature and deal with 'raw' data of sensor networks. Stream segmentation is defined using Bayesian Networks in the context of sensor networks, and two application examples are given to demonstrate the usefulness of the approach.展开更多
Global warming has caused the Arctic Ocean ice cover to shrink.This endangers the environment but has made traversing the Arctic channel possible.Therefore,the strategic position of the Arctic has been significantly i...Global warming has caused the Arctic Ocean ice cover to shrink.This endangers the environment but has made traversing the Arctic channel possible.Therefore,the strategic position of the Arctic has been significantly improved.As a near-Arctic country,China has formulated relevant policies that will be directly impacted by changes in the international relations between the eight Arctic countries(regions).A comprehensive and real-time analysis of the various characteristics of the Arctic geographical relationship is required in China,which helps formulate political,economic,and diplomatic countermeasures.Massive global real-time open databases provide news data from major media in various countries.This makes it possible to monitor geographical relationships in real-time.This paper explores key elements of the social development of eight Arctic countries(regions)over 2013-2019 based on the GDELT database and the method of labeled latent Dirichlet allocation.This paper also constructs the national interaction network and identifies the evolution pattern for the relationships between Arctic countries(regions).The following conclusions are drawn.(1)Arctic news hotspot is now focusing on climate change/ice cap melting which is becoming the main driving factor for changes in geographical relationships in the Arctic.(2)There is a strong correlation between the number of news pieces about ice cap melting and the sea ice area.(3)With the melting of the ice caps,the social,economic,and military activities in the Arctic have been booming,and the competition for dominance is becoming increasingly fierce.In general,there is a pattern of domination by Russia and Canada.展开更多
Currently,ocean data portals are being developed around the world based on Geographic Information Systems(GIS) as a source of ocean data and information.However,given the relatively high temporal frequency and the int...Currently,ocean data portals are being developed around the world based on Geographic Information Systems(GIS) as a source of ocean data and information.However,given the relatively high temporal frequency and the intrinsic spatial nature of ocean data and information,no current GIS software is adequate to deal effectively and efficiently with spatiotemporal data.Furthermore,while existing ocean data portals are generally designed to meet the basic needs of a broad range of users,they are sometimes very complicated for general audiences,especially for those without training in GIS.In this paper,a new technical architecture for an ocean data integration and service system is put forward that consists of four layers:the operation layer,the extract,transform,and load(ETL) layer,the data warehouse layer,and the presentation layer.The integration technology based on the XML,ontology,and spatiotemporal data organization scheme for the data warehouse layer is then discussed.In addition,the ocean observing data service technology realized in the presentation layer is also discussed in detail,including the development of the web portal and ocean data sharing platform.The application on the Taiwan Strait shows that the technology studied in this paper can facilitate sharing,access,and use of ocean observation data.The paper is based on an ongoing research project for the development of an ocean observing information system for the Taiwan Strait that will facilitate the prevention of ocean disasters.展开更多
Under the macro background of rapid urbanization and social transformation in China,campus space renewal has become an important practice and carrier for the sustainable development of schools.The study on campus spac...Under the macro background of rapid urbanization and social transformation in China,campus space renewal has become an important practice and carrier for the sustainable development of schools.The study on campus space by big data and quantitative reflection of spatial distribution of applicable people in different areas of the campus can provide a certain scientific basis for campus space updating.West campus of Yangtze University is taken as research object.Based on cognitive map method,questionnaire survey method,behavior trajectory and correlation analysis method,the types and characteristics of campus space composition,campus satisfaction,usage and its relevance are analyzed.Research results show that ①the overall imageability of campus space is higher,which has a significantly positive correlation with the satisfaction of campus environment,and has no correlation with users’ behavior activities.The use frequency of non teaching areas varies greatly in different periods of time.②The correlation between the surrounding green vegetation and the image degree of campus landmarks is the most significant,and the coefficient is 0.886.③The correlation between spatial size suitability and regional image degree is the most significant,and the coefficient is 0.937.④The correlation between public activity facilities in the region and node image degree is the most significant,and the coefficient is 0.995.According to the research results,the corresponding solutions are put forward to provide scientific and quantitative reference suggestions for the renewal and transformation of the campus.展开更多
Spatio-temporal heterogeneous data is the database for decisionmaking in many fields,and checking its accuracy can provide data support for making decisions.Due to the randomness,complexity,global and local correlatio...Spatio-temporal heterogeneous data is the database for decisionmaking in many fields,and checking its accuracy can provide data support for making decisions.Due to the randomness,complexity,global and local correlation of spatiotemporal heterogeneous data in the temporal and spatial dimensions,traditional detection methods can not guarantee both detection speed and accuracy.Therefore,this article proposes a method for detecting the accuracy of spatiotemporal heterogeneous data by fusing graph convolution and temporal convolution networks.Firstly,the geographic weighting function is introduced and improved to quantify the degree of association between nodes and calculate the weighted adjacency value to simplify the complex topology.Secondly,design spatiotemporal convolutional units based on graph convolutional neural networks and temporal convolutional networks to improve detection speed and accuracy.Finally,the proposed method is compared with three methods,ARIMA,T-GCN,and STGCN,in real scenarios to verify its effectiveness in terms of detection speed,detection accuracy and stability.The experimental results show that the RMSE,MAE,and MAPE of this method are the smallest in the cases of simple connectivity and complex connectivity degree,which are 13.82/12.08,2.77/2.41,and 16.70/14.73,respectively.Also,it detects the shortest time of 672.31/887.36,respectively.In addition,the evaluation results are the same under different time periods of processing and complex topology environment,which indicates that the detection accuracy of this method is the highest and has good research value and application prospects.展开更多
The burgeoning field of intelligent transportation systems(ITS)has been pivotal in addressing contemporary traffic challenges,significantly benefiting from the evolution of computational capabilities and sensor techno...The burgeoning field of intelligent transportation systems(ITS)has been pivotal in addressing contemporary traffic challenges,significantly benefiting from the evolution of computational capabilities and sensor technologies.This surge in technical advancement has paved the way for extensive reliance on deep-learning methodologies to exploit largescale traffic data.Such efforts are directed toward decoding the intricate spatiotemporal dynamics inherent in traffic prediction.This study delves into the realm of traffic prediction,encompassing time series,spatiotemporal,and origin-destination(OD)predictions,to dissect the nuances among various predictive methodologies.Through a meticulous examination,this paper highlights the efficacy of spatiotemporal coupling techniques in enhancing prediction accuracy.Furthermore,it scrutinizes the existing challenges and delineates open and new questions within the traffic prediction domain,thereby charting out prospective avenues for future research endeavors.展开更多
Lightning is a significant natural hazard that poses considerable risks to both human safety and industrial operations.Accurate,fine-scale lightning forecasting is crucial for effective disaster prevention.Traditional...Lightning is a significant natural hazard that poses considerable risks to both human safety and industrial operations.Accurate,fine-scale lightning forecasting is crucial for effective disaster prevention.Traditional forecasting methods primarily rely on numerical weather prediction(NWP),which demands substantial computational resources to solve complex atmospheric evolution equations.Recently,deep learning-based weather prediction models—particularly weather foundation models(WFMs)—have demonstrated promising results,achieving performance comparable to NWP while requiring substantially fewer computational resources.However,existing WFMs are unable to directly generate lightning forecasts and struggle to satisfy the high spatial resolution required for fine-scale prediction.To address these limitations,this paper investigates a fine-scale lightning forecasting approach based on WFMs and proposes a dual-source data-driven forecasting framework that integrates the strengths of both WFMs and recent lightning observations to enhance predictive performance.Furthermore,a gated spatiotemporal fusion network(gSTFNet)is designed to address the challenges of cross-temporal and cross-modal fusion inherent in dual-source data integration.gSTFNet employs a dual-encoding structure to separately encode features from WFMs and lightning observations,effectively narrowing the modal gap in the latent feature space.A gated spatiotemporal fusion module is then introduced to model the spatiotemporal correlations between the two types of features,facilitating seamless cross-temporal fusion.The fused features are subsequently processed by a deconvolutional network to generate accurate lightning forecasts.We evaluate the proposed gSTFNet using real-world lightning observation data collected in Guangdong from 2018 to 2022.Experimental results demonstrate that:(1)In terms of the ETS score,the dual-source framework achieves a 50% improvement over models trained solely on WFMs,and a 300% improvement over the HRES lightning forecasting product released by the European Centre for Medium-Range Weather Forecasts(ECMWF);(2)gSTFNet outperforms several state-of-the-art deep learning baselines that utilize dual-source inputs,clearly demonstrating superior forecasting accuracy.展开更多
PM2.5 concentration prediction is of great significance to environmental protection and human health.Achieving accurate prediction of PM2.5 concentration has become an important research task.However,PM2.5 pollutants ...PM2.5 concentration prediction is of great significance to environmental protection and human health.Achieving accurate prediction of PM2.5 concentration has become an important research task.However,PM2.5 pollutants can spread in the earth’s atmosphere,causing mutual influence between different cities.To effectively capture the air pollution relationship between cities,this paper proposes a novel spatiotemporal model combining graph attention neural network(GAT)and gated recurrent unit(GRU),named GAT-GRU for PM2.5 concentration prediction.Specifically,GAT is used to learn the spatial dependence of PM2.5 concentration data in different cities,and GRU is to extract the temporal dependence of the long-term data series.The proposed model integrates the learned spatio-temporal dependencies to capture long-term complex spatio-temporal features.Considering that air pollution is related to the meteorological conditions of the city,the knowledge acquired from meteorological data is used in the model to enhance PM2.5 prediction performance.The input of the GAT-GRU model consists of PM2.5 concentration data and meteorological data.In order to verify the effectiveness of the proposed GAT-GRU prediction model,this paper designs experiments on real-world datasets compared with other baselines.Experimental results prove that our model achieves excellent performance in PM2.5 concentration prediction.展开更多
As the basic data of digital city and smart city research,Spatiotemporal series data contain rich geographic information.Alongside the accumulation of spatial time-series data,we are also encountering new challenges r...As the basic data of digital city and smart city research,Spatiotemporal series data contain rich geographic information.Alongside the accumulation of spatial time-series data,we are also encountering new challenges related to analyzing and mining the correlations among the data.Because the traditional methods of analysis also have their own suitable condition restrictions for the new features,we propose a new analytical framework based on sparse representation to describe the time,space,and spatial-time correlation.First,before analyzing the correlation,we discuss sparse representation based on the K-singular value decomposition(K-SVD)algorithm to ensure that the sparse coefficients are in the same sparse domain.We then present new computing methods to calculate the time,spatial,and spatial-time correlation coefficients in the sparse domain;we then discuss the functions’properties.Finally,we discuss change regulations for the gross domestic product(GDP),population,and Normalized Difference Vegetation Index(NDVI)spatial time-series data in China’s Jing-Jin-Ji region to confirm the effectiveness and adaptability of the new methods.展开更多
Taxi demand prediction is a crucial component of intelligent transportation system research.Compared to region-based demand prediction,origin-destination(OD)demand prediction has a wide range of potential applications...Taxi demand prediction is a crucial component of intelligent transportation system research.Compared to region-based demand prediction,origin-destination(OD)demand prediction has a wide range of potential applications,including real-time matching,idle vehicle allocation,ridesharing services,and dynamic pricing,among others.However,because OD demand involves complex spatiotemporal dependence,research in this area has been limited thus far.In this paper,we first review existing research from four perspectives:topology construction,temporal and spatial feature processing,and other relevant factors.We then elaborate on the advantages and limitations of OD prediction methods based on deep learning architecture theory.Next,we discuss ongoing challenges in OD prediction,such as dynamics,spatiotemporal dependence,semantic differentiation,time window selection,and data sparsity problems,and summarize and compare potential solutions to each challenge.These findings offer valuable insights for model selection in OD demand prediction.Finally,we provide public datasets and open-source code,along with suggestions for future research directions.展开更多
Urban sensing is one of the fundamental building blocks of urban computing.It uses various types of sensors deployed in different geospatial locations to continuously and cooperatively monitor the natural and cultural...Urban sensing is one of the fundamental building blocks of urban computing.It uses various types of sensors deployed in different geospatial locations to continuously and cooperatively monitor the natural and cultural environment in urban areas.Nevertheless,issues such as uneven distribution,low sampling rate and high failure ratio of sensors often make their readings less reliable.This paper provides an innovative framework to detect the noise data as well as to repair them from a spatial-temporal causality perspective rather than to deal with them inclividually.This can be achieved by connecting data through monitored objects,using the Skip-gram model to estimate spatial correlation and long shortterm memory to estimate temporal correlation.The framework consists of three major modules:1)a space embedded Bidirectional Long Short-Term Memory(BiLSTM)-based sequence labeling module to detect the noise data and the latent missing data;2)a space embedded BiLSTM-based sequence predicting module calculating the value of the missing data;3)an object characteristics fusion repairing module to correct the spatial and temporal dislocation sensory data.The approach is evaluated with real-world data collected by over 3000 electronic traffic bayonet devices in a citywide scale of a medium-sized city in China,and the result is superior to those of several referenced approaches.With a 12.9%improvement,in data accuracy over the raw data,the proposed framework plays a significant,role in various real-world use cases in urban governance,such as criminal investigation,traffic violation monitoring,and equipment maintenance.展开更多
With the increasing development of intelligent detection devices,a vast amount of traffic flow data can be collected from intelligent transportation systems.However,these data often encounter issues such as missing an...With the increasing development of intelligent detection devices,a vast amount of traffic flow data can be collected from intelligent transportation systems.However,these data often encounter issues such as missing and abnormal values,which can adversely affect the accuracy of future tasks like traffic flow forecasting.To address this problem,this paper proposes the Attention-based Spatiotemporal Generative Adversarial Imputation Network(ASTGAIN)model,comprising a generator and a discriminator,to conduct traffic volume imputation.The generator incorporates an information fuse module,a spatial attention mechanism,a causal inference module and a temporal attention mechanism,enabling it to capture historical information and extract spatiotemporal relationships from the traffic flow data.The discriminator features a bidirectional gated recurrent unit,which explores the temporal correlation of the imputed data to distinguish between imputed and original values.Additionally,we have devised an imputation filling technique that fully leverages the imputed data to enhance the imputation performance.Comparison experiments with several traditional imputation models demonstrate the superior performance of the ASTGAIN model across diverse missing scenarios.展开更多
Big Earth data are produced from satellite observations,Internet-ofThings,model simulations,and other sources.The data embed unprecedented insights and spatiotemporal stamps of relevant Earth phenomena for improving o...Big Earth data are produced from satellite observations,Internet-ofThings,model simulations,and other sources.The data embed unprecedented insights and spatiotemporal stamps of relevant Earth phenomena for improving our understanding,responding,and addressing challenges of Earth sciences and applications.In the past years,new technologies(such as cloud computing,big data and artificial intelligence)have gained momentum in addressing the challenges of using big Earth data for scientific studies and geospatial applications historically intractable.This paper reviews the big Earth data analytics from several aspects to capture the latest advancements in this fast-growing domain.We first introduce the concepts of big Earth data.The architecture,various functionalities,and supporting modules are then reviewed from a generic methodology aspect.Analytical methods supporting the functionalities are surveyed and analyzed in the context of different tools.The driven questions are exemplified through cutting-edge Earth science researches and applications.A list of challenges and opportunities are proposed for different stakeholders to collaboratively advance big Earth data analytics in the near future.展开更多
Rich observation data generated by ubiquitous sensors are vital for wetland monitoring,spanning from the prediction of natural disasters to emergency response.Such sensors use different data acquisition and descriptio...Rich observation data generated by ubiquitous sensors are vital for wetland monitoring,spanning from the prediction of natural disasters to emergency response.Such sensors use different data acquisition and description methods and,if combined,could provide a comprehensive description of the wetland.Unfortunately,these data remain hidden in isolated silos,and their variety makes integration and interoperability a significant challenge.In this work,we develop a semantic model for wetland monitoring data using an agile and modular approach,namely,wetland monitoring ontology(WMO),which containsfive modules:wetland ecosystem,monitoring indicator,monitoring context,geospatial context,and temporal context.The proposed ontology supports the semantic interoperability and integration of wetland monitoring data from multiple sources,domains,modes,and spatiotemporal scales.We also provide two real-world use cases to validate the WMO and demonstrate the WMO’s usability and reusability.展开更多
基金supported by the National Natural Science Foundation of China(Project Nos.42271331 and 42022060)The Hong Kong Polytechnic University(Project Nos.4-ZZND and Q-CDBP).
文摘Spatiotemporal data fusion technologies have been widely used for land surface phenology(LSP)monitoring since it is a low-cost solution to obtain fine-resolution satellite time series.However,the reliability of fused images is largely affected by land surface heterogeneity and input data.It is unclear whether data fusion can really benefit LSP studies at fine scales.To explore this research question,this study designed a sophisticated simulation experiment to quantify effectiveness of 2 representative data fusion algorithms,namely,pair-based Spatial and Temporal Adaptive Reflectance Fusion Model(STARFM)and time series-based Spatiotemporal fusion method to Simultaneously generate Full-length normalized difference vegetation Index Time series(SSFIT)by fusing Landsat and Moderate Resolution Imaging Spectroradiometer(MODIS)data in extracting pixel-wise spring phenology(i.e.,the start of the growing season,SOS)and its spatial gradient and temporal variation.Our results reveal that:(a)STARFM can improve the accuracy of pixel-wise SOS by up to 74.47%and temporal variation by up to 59.13%,respectively,compared with only using Landsat images,but it can hardly improve the retrieval of spatial gradient.For SSFIT,the accuracy of pixel-wise SOS,spatial gradient,and temporal variation can be improved by up to 139.20%,26.36%,and 162.30%,respectively;(b)the accuracy improvement introduced by fusion algorithms decreases with the number of available Landsat images per year,and it has a large variation with the same number of available Landsat images,and(c)this large variation is highly related to the temporal distributions of available Landsat images,suggesting that fusion algorithms can improve SOS accuracy only when cloud-free Landsat images cannot capture key vegetation growth period.This study calls for caution with the use of data fusion in LSP studies at fine scales.
基金The research presented in this paper was funded by the National Science Foundation(1841520 and 1835507).
文摘Under the global health crisis of COVID-19,timely,and accurate epi-demic data are important for observation,monitoring,analyzing,modeling,predicting,and mitigating impacts.Viral case data can be jointly analyzed with relevant factors for various applications in the context of the pandemic.Current COVID-19 case data are scattered across a variety of data sources which may consist of low data quality accompanied by inconsistent data structures.To address this short-coming,a multi-scale spatiotemporal data product is proposed as a public repository platform,based on a spatiotemporal cube,and allows the integration of different data sources by adopting various data standards.Within the spatiotemporal cube,a comprehensive data processing workflow gathers disparate COVID-19 epidemic data-sets at the global,national,provincial/state,county,and city levels.This proposed framework is supported by an automatic update with a 2-h frequency and the crowdsourcing validation team to produce and update data on a daily time step.This rapid-response dataset allows the integration of other relevant socio-economic and environ-mental factors for spatiotemporal analysis.The data is available in Harvard Dataverse platform(https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/8HGECN)and GitHub open source repository(https://github.com/stccenter/COVID-19-Data).
基金Publication of this article was funded in part by the George Mason University Libraries Open Access Publishing Fund.
文摘In the research field of spatiotemporal data discovery,how to utilize the semantic characteristics of spatiotemporal datasets is an important topic.This paper presented a content-based recommendation method,and applied Bayesian networks and ontologies into the vocabulary recommendation process for spatiotemporal data discovery.The source data of this research was from the MUDROD(Mining and Utilizing Dataset Relevancy from Oceanographic Datasets)search platform.From the historical search log,major keywords were extracted and organized according to ontologies in a hierarchical structure.Using the search history,the posterior probability between each subclass and their super class in the ontologies was calculated,indicating a recommendation likelihood.We created a Bayesian network model for inference based on ontologies.This model can address the following two objectives:(1)Given one class in the ontology,the model can judge which class has the biggest likelihood to be selected for recommendation.(2)Based on the search history of a user,the Bayesian network model can judge which class has the biggest probability to be recommended.Comparison experimentation with existing system and evaluation experimentation with expert knowledge show that this method is specifically helpful for spatiotemporal data discovery.
基金supported by the Institute of Information&Communications Technology Planning&Evaluation (IITP)grant funded by the Korean government (MSIT) (No.2022-0-00369)by the NationalResearch Foundation of Korea Grant funded by the Korean government (2018R1A5A1060031,2022R1F1A1065664).
文摘How can we efficiently store and mine dynamically generated dense tensors for modeling the behavior of multidimensional dynamic data?Much of the multidimensional dynamic data in the real world is generated in the form of time-growing tensors.For example,air quality tensor data consists of multiple sensory values gathered from wide locations for a long time.Such data,accumulated over time,is redundant and consumes a lot ofmemory in its raw form.We need a way to efficiently store dynamically generated tensor data that increase over time and to model their behavior on demand between arbitrary time blocks.To this end,we propose a Block IncrementalDense Tucker Decomposition(BID-Tucker)method for efficient storage and on-demand modeling ofmultidimensional spatiotemporal data.Assuming that tensors come in unit blocks where only the time domain changes,our proposed BID-Tucker first slices the blocks into matrices and decomposes them via singular value decomposition(SVD).The SVDs of the time×space sliced matrices are stored instead of the raw tensor blocks to save space.When modeling from data is required at particular time blocks,the SVDs of corresponding time blocks are retrieved and incremented to be used for Tucker decomposition.The factor matrices and core tensor of the decomposed results can then be used for further data analysis.We compared our proposed BID-Tucker with D-Tucker,which our method extends,and vanilla Tucker decomposition.We show that our BID-Tucker is faster than both D-Tucker and vanilla Tucker decomposition and uses less memory for storage with a comparable reconstruction error.We applied our proposed BID-Tucker to model the spatial and temporal trends of air quality data collected in South Korea from 2018 to 2022.We were able to model the spatial and temporal air quality trends.We were also able to verify unusual events,such as chronic ozone alerts and large fire events.
基金Sponsored by the Project of Enhancing Basic Scientific Research Ability of Young and Middle-aged Teachers in Guangxi Universities in 2021:Research on the Distribution Characteristics and Architectural Style of Minority Settlements in Typical Areas of Northern Guangxi (2021KY0166)the Scientific Research Foundation of Guangxi University for Nationalities in 2020:Study on the Characteristics of Slope Sliding Surface and Early Warning of Landslide (2020KJQD26)。
文摘Public space as an extension of private living spaces carries the different social life and customs of human settlement.To analyze the spatial distribution characteristics of traditional villages in northern Guangxi based on spatial syntax and its influencing factors,this paper analyzed and compared the spatial structure and morphology of traditional villages in northern Guangxi by using the theory of spatial syntax and linguistics as the quantitative analysis method of spatial syntax,and verified the feasibility of expanding the application of spatial syntax,finally,the generality and characteristics of the spatial structure and form of traditional villages in northern Guangxi were put forward.Protection has been implemented.According to the comprehensibility data in this paper,the comprehensibility of the village 1 in northern Guangxi is 0.52,the village 2 is 0.40,the village 3 is 0.35,the village 4 is 0.48,the village 5 is 0.55 and the village 6 is 0.50.It showed that in the selected 6 village samples,except for the 3 ones in northern Guangxi,the local space of the other 3 villages could better perceive the overall space,which also reflected the overall space permeability of most traditional villages in northern Guangxi was good.
基金The National Natural Science Foundation of China under contract Nos T2421002, 623B2071,and 42125601the National Key R&D Program of China under contract No. 2023YFF0805300
文摘Oceanic dissolved oxygen(DO)in the ocean has an indispensable role on supporting biological respiration,maintaining ecological balance and promoting nutrient cycling.According to existing research,the total DO has declined by 2%of the total over the past 50 a,and the tropical Pacific Ocean occupied the largest oxygen minimum zone(OMZ)areas.However,the sparse observation data is limited to understanding the dynamic variation and trend of ocean using traditional interpolation methods.In this study,we applied different machine learning algorithms to fit regression models between measured DO,ocean reanalysis physical variables,and spatiotemporal variables.We demonstrate that extreme gradient boosting(XGBoost)model has the best performance,hereby reconstructing a four-dimensional DO dataset of the tropical Pacific Ocean from 1920 to 2023.The results reveal that XGBoost significantly improves the reconstruction performance in the tropical Pacific Ocean,with a 35.3%reduction in root mean-squared error and a 39.5%decrease in mean absolute error.Additionally,we compare the results with three Coupled Model Intercomparison Project Phase 6(CMIP6)models data to confirm the high accuracy of the 4-dimensional reconstruction.Overall,the OMZ mainly dominates the eastern tropical Pacific Ocean,with a slow expansion.This study used XGBoost to efficiently reconstructing 4-dimensional DO enhancing the understanding of the hypoxic expansion in the tropical Pacific Ocean and we foresee that this approach would be extended to reconstruct more ocean elements.
文摘Sensor networks provide means to link people with real world by processing data in real time collected from real-world and routing the query results to the right people. Application examples include continuous monitoring of environment, building infrastructures and human health. Many researchers view the sensor networks as databases, and the monitoring tasks are performed as subscriptions, queries, and alert. However, this point is not precise. First, databases can only deal with well-formed data types, with well-defined schema for their interpretation, while the raw data collected by the sensor networks, in most cases, do not fit to this requirement. Second, sensor networks have to deal with very dynamic targets, environment and resources, while databases are more static. In order to fill this gap between sensor networks and databases, we propose a novel approach, referred to as 'spatiotemporal data stream segmentation', or 'stream segmentation' for short, to address the dynamic nature and deal with 'raw' data of sensor networks. Stream segmentation is defined using Bayesian Networks in the context of sensor networks, and two application examples are given to demonstrate the usefulness of the approach.
基金National Natural Science Foundation of China(42071153)The Strategic Priority Research Program of Chinese Academy of Sciences(XDA19040401)The Strategic Priority Research Program of Chinese Academy of Sciences(XDA20080100)。
文摘Global warming has caused the Arctic Ocean ice cover to shrink.This endangers the environment but has made traversing the Arctic channel possible.Therefore,the strategic position of the Arctic has been significantly improved.As a near-Arctic country,China has formulated relevant policies that will be directly impacted by changes in the international relations between the eight Arctic countries(regions).A comprehensive and real-time analysis of the various characteristics of the Arctic geographical relationship is required in China,which helps formulate political,economic,and diplomatic countermeasures.Massive global real-time open databases provide news data from major media in various countries.This makes it possible to monitor geographical relationships in real-time.This paper explores key elements of the social development of eight Arctic countries(regions)over 2013-2019 based on the GDELT database and the method of labeled latent Dirichlet allocation.This paper also constructs the national interaction network and identifies the evolution pattern for the relationships between Arctic countries(regions).The following conclusions are drawn.(1)Arctic news hotspot is now focusing on climate change/ice cap melting which is becoming the main driving factor for changes in geographical relationships in the Arctic.(2)There is a strong correlation between the number of news pieces about ice cap melting and the sea ice area.(3)With the melting of the ice caps,the social,economic,and military activities in the Arctic have been booming,and the competition for dominance is becoming increasingly fierce.In general,there is a pattern of domination by Russia and Canada.
基金Supported by National High Technology Research and Development Program of China (863 Program) (Nos. 2009AA12Z225,2009AA12Z208)the National Natural Science Foundation of China (No. 61074132)
文摘Currently,ocean data portals are being developed around the world based on Geographic Information Systems(GIS) as a source of ocean data and information.However,given the relatively high temporal frequency and the intrinsic spatial nature of ocean data and information,no current GIS software is adequate to deal effectively and efficiently with spatiotemporal data.Furthermore,while existing ocean data portals are generally designed to meet the basic needs of a broad range of users,they are sometimes very complicated for general audiences,especially for those without training in GIS.In this paper,a new technical architecture for an ocean data integration and service system is put forward that consists of four layers:the operation layer,the extract,transform,and load(ETL) layer,the data warehouse layer,and the presentation layer.The integration technology based on the XML,ontology,and spatiotemporal data organization scheme for the data warehouse layer is then discussed.In addition,the ocean observing data service technology realized in the presentation layer is also discussed in detail,including the development of the web portal and ocean data sharing platform.The application on the Taiwan Strait shows that the technology studied in this paper can facilitate sharing,access,and use of ocean observation data.The paper is based on an ongoing research project for the development of an ocean observing information system for the Taiwan Strait that will facilitate the prevention of ocean disasters.
文摘Under the macro background of rapid urbanization and social transformation in China,campus space renewal has become an important practice and carrier for the sustainable development of schools.The study on campus space by big data and quantitative reflection of spatial distribution of applicable people in different areas of the campus can provide a certain scientific basis for campus space updating.West campus of Yangtze University is taken as research object.Based on cognitive map method,questionnaire survey method,behavior trajectory and correlation analysis method,the types and characteristics of campus space composition,campus satisfaction,usage and its relevance are analyzed.Research results show that ①the overall imageability of campus space is higher,which has a significantly positive correlation with the satisfaction of campus environment,and has no correlation with users’ behavior activities.The use frequency of non teaching areas varies greatly in different periods of time.②The correlation between the surrounding green vegetation and the image degree of campus landmarks is the most significant,and the coefficient is 0.886.③The correlation between spatial size suitability and regional image degree is the most significant,and the coefficient is 0.937.④The correlation between public activity facilities in the region and node image degree is the most significant,and the coefficient is 0.995.According to the research results,the corresponding solutions are put forward to provide scientific and quantitative reference suggestions for the renewal and transformation of the campus.
基金supported by the National Natural Science Foundation of China under Grants 42172161by the Heilongjiang Provincial Natural Science Foundation of China under Grant LH2020F003+2 种基金by the Heilongjiang Provincial Department of Education Project of China under Grants UNPYSCT-2020144by the Innovation Guidance Fund of Heilongjiang Province of China under Grants 15071202202by the Science and Technology Bureau Project of Qinhuangdao Province of China under Grants 202101A226.
文摘Spatio-temporal heterogeneous data is the database for decisionmaking in many fields,and checking its accuracy can provide data support for making decisions.Due to the randomness,complexity,global and local correlation of spatiotemporal heterogeneous data in the temporal and spatial dimensions,traditional detection methods can not guarantee both detection speed and accuracy.Therefore,this article proposes a method for detecting the accuracy of spatiotemporal heterogeneous data by fusing graph convolution and temporal convolution networks.Firstly,the geographic weighting function is introduced and improved to quantify the degree of association between nodes and calculate the weighted adjacency value to simplify the complex topology.Secondly,design spatiotemporal convolutional units based on graph convolutional neural networks and temporal convolutional networks to improve detection speed and accuracy.Finally,the proposed method is compared with three methods,ARIMA,T-GCN,and STGCN,in real scenarios to verify its effectiveness in terms of detection speed,detection accuracy and stability.The experimental results show that the RMSE,MAE,and MAPE of this method are the smallest in the cases of simple connectivity and complex connectivity degree,which are 13.82/12.08,2.77/2.41,and 16.70/14.73,respectively.Also,it detects the shortest time of 672.31/887.36,respectively.In addition,the evaluation results are the same under different time periods of processing and complex topology environment,which indicates that the detection accuracy of this method is the highest and has good research value and application prospects.
基金supported by the National Natural Science Foundation of China(62273057)。
文摘The burgeoning field of intelligent transportation systems(ITS)has been pivotal in addressing contemporary traffic challenges,significantly benefiting from the evolution of computational capabilities and sensor technologies.This surge in technical advancement has paved the way for extensive reliance on deep-learning methodologies to exploit largescale traffic data.Such efforts are directed toward decoding the intricate spatiotemporal dynamics inherent in traffic prediction.This study delves into the realm of traffic prediction,encompassing time series,spatiotemporal,and origin-destination(OD)predictions,to dissect the nuances among various predictive methodologies.Through a meticulous examination,this paper highlights the efficacy of spatiotemporal coupling techniques in enhancing prediction accuracy.Furthermore,it scrutinizes the existing challenges and delineates open and new questions within the traffic prediction domain,thereby charting out prospective avenues for future research endeavors.
基金supported by the Open Grants of Key Laboratory of Lightning,China Meteorological Administration(Grant Nos.2023KELL-B002 and 2024KELL-A001)the National Natural Science Foundation of China(Grant Nos.62306028,42075088 and U2342215)the Science and Technology Program of Shenzhen,China(Grant No.KJZD20240903102742055)。
文摘Lightning is a significant natural hazard that poses considerable risks to both human safety and industrial operations.Accurate,fine-scale lightning forecasting is crucial for effective disaster prevention.Traditional forecasting methods primarily rely on numerical weather prediction(NWP),which demands substantial computational resources to solve complex atmospheric evolution equations.Recently,deep learning-based weather prediction models—particularly weather foundation models(WFMs)—have demonstrated promising results,achieving performance comparable to NWP while requiring substantially fewer computational resources.However,existing WFMs are unable to directly generate lightning forecasts and struggle to satisfy the high spatial resolution required for fine-scale prediction.To address these limitations,this paper investigates a fine-scale lightning forecasting approach based on WFMs and proposes a dual-source data-driven forecasting framework that integrates the strengths of both WFMs and recent lightning observations to enhance predictive performance.Furthermore,a gated spatiotemporal fusion network(gSTFNet)is designed to address the challenges of cross-temporal and cross-modal fusion inherent in dual-source data integration.gSTFNet employs a dual-encoding structure to separately encode features from WFMs and lightning observations,effectively narrowing the modal gap in the latent feature space.A gated spatiotemporal fusion module is then introduced to model the spatiotemporal correlations between the two types of features,facilitating seamless cross-temporal fusion.The fused features are subsequently processed by a deconvolutional network to generate accurate lightning forecasts.We evaluate the proposed gSTFNet using real-world lightning observation data collected in Guangdong from 2018 to 2022.Experimental results demonstrate that:(1)In terms of the ETS score,the dual-source framework achieves a 50% improvement over models trained solely on WFMs,and a 300% improvement over the HRES lightning forecasting product released by the European Centre for Medium-Range Weather Forecasts(ECMWF);(2)gSTFNet outperforms several state-of-the-art deep learning baselines that utilize dual-source inputs,clearly demonstrating superior forecasting accuracy.
基金Authors The research project is partially supported by National Natural ScienceFoundation of China under Grant No. 62072015, U19B2039, U1811463National Key R&D Programof China 2018YFB1600903.
文摘PM2.5 concentration prediction is of great significance to environmental protection and human health.Achieving accurate prediction of PM2.5 concentration has become an important research task.However,PM2.5 pollutants can spread in the earth’s atmosphere,causing mutual influence between different cities.To effectively capture the air pollution relationship between cities,this paper proposes a novel spatiotemporal model combining graph attention neural network(GAT)and gated recurrent unit(GRU),named GAT-GRU for PM2.5 concentration prediction.Specifically,GAT is used to learn the spatial dependence of PM2.5 concentration data in different cities,and GRU is to extract the temporal dependence of the long-term data series.The proposed model integrates the learned spatio-temporal dependencies to capture long-term complex spatio-temporal features.Considering that air pollution is related to the meteorological conditions of the city,the knowledge acquired from meteorological data is used in the model to enhance PM2.5 prediction performance.The input of the GAT-GRU model consists of PM2.5 concentration data and meteorological data.In order to verify the effectiveness of the proposed GAT-GRU prediction model,this paper designs experiments on real-world datasets compared with other baselines.Experimental results prove that our model achieves excellent performance in PM2.5 concentration prediction.
基金This work is supported by the National Natural Science Foundation of China[No.41471368 and No.41571413].
文摘As the basic data of digital city and smart city research,Spatiotemporal series data contain rich geographic information.Alongside the accumulation of spatial time-series data,we are also encountering new challenges related to analyzing and mining the correlations among the data.Because the traditional methods of analysis also have their own suitable condition restrictions for the new features,we propose a new analytical framework based on sparse representation to describe the time,space,and spatial-time correlation.First,before analyzing the correlation,we discuss sparse representation based on the K-singular value decomposition(K-SVD)algorithm to ensure that the sparse coefficients are in the same sparse domain.We then present new computing methods to calculate the time,spatial,and spatial-time correlation coefficients in the sparse domain;we then discuss the functions’properties.Finally,we discuss change regulations for the gross domestic product(GDP),population,and Normalized Difference Vegetation Index(NDVI)spatial time-series data in China’s Jing-Jin-Ji region to confirm the effectiveness and adaptability of the new methods.
基金supported by 2022 Shenyang Philosophy and Social Science Planning under grant SY202201Z,Liaoning Provincial Department of Education Project under grant LJKZ0588.
文摘Taxi demand prediction is a crucial component of intelligent transportation system research.Compared to region-based demand prediction,origin-destination(OD)demand prediction has a wide range of potential applications,including real-time matching,idle vehicle allocation,ridesharing services,and dynamic pricing,among others.However,because OD demand involves complex spatiotemporal dependence,research in this area has been limited thus far.In this paper,we first review existing research from four perspectives:topology construction,temporal and spatial feature processing,and other relevant factors.We then elaborate on the advantages and limitations of OD prediction methods based on deep learning architecture theory.Next,we discuss ongoing challenges in OD prediction,such as dynamics,spatiotemporal dependence,semantic differentiation,time window selection,and data sparsity problems,and summarize and compare potential solutions to each challenge.These findings offer valuable insights for model selection in OD demand prediction.Finally,we provide public datasets and open-source code,along with suggestions for future research directions.
基金supported in part by the National Key Research and Development Program of China under Grant No.2018YFC0-831500.
文摘Urban sensing is one of the fundamental building blocks of urban computing.It uses various types of sensors deployed in different geospatial locations to continuously and cooperatively monitor the natural and cultural environment in urban areas.Nevertheless,issues such as uneven distribution,low sampling rate and high failure ratio of sensors often make their readings less reliable.This paper provides an innovative framework to detect the noise data as well as to repair them from a spatial-temporal causality perspective rather than to deal with them inclividually.This can be achieved by connecting data through monitored objects,using the Skip-gram model to estimate spatial correlation and long shortterm memory to estimate temporal correlation.The framework consists of three major modules:1)a space embedded Bidirectional Long Short-Term Memory(BiLSTM)-based sequence labeling module to detect the noise data and the latent missing data;2)a space embedded BiLSTM-based sequence predicting module calculating the value of the missing data;3)an object characteristics fusion repairing module to correct the spatial and temporal dislocation sensory data.The approach is evaluated with real-world data collected by over 3000 electronic traffic bayonet devices in a citywide scale of a medium-sized city in China,and the result is superior to those of several referenced approaches.With a 12.9%improvement,in data accuracy over the raw data,the proposed framework plays a significant,role in various real-world use cases in urban governance,such as criminal investigation,traffic violation monitoring,and equipment maintenance.
基金funded in part by Key R&D Program of Hunan Province(Grant No.2023GK2014)Key technology projects in the transportation industry(Grant No.2022-ZD6-077)+1 种基金Transportation Science and Technology Plan Project of Shandong Transportation Department(Grant No.2022B62)the Fundamental Research Funds for the Central Universities of Central South University(Grant No.2023ZZTS0683)。
文摘With the increasing development of intelligent detection devices,a vast amount of traffic flow data can be collected from intelligent transportation systems.However,these data often encounter issues such as missing and abnormal values,which can adversely affect the accuracy of future tasks like traffic flow forecasting.To address this problem,this paper proposes the Attention-based Spatiotemporal Generative Adversarial Imputation Network(ASTGAIN)model,comprising a generator and a discriminator,to conduct traffic volume imputation.The generator incorporates an information fuse module,a spatial attention mechanism,a causal inference module and a temporal attention mechanism,enabling it to capture historical information and extract spatiotemporal relationships from the traffic flow data.The discriminator features a bidirectional gated recurrent unit,which explores the temporal correlation of the imputed data to distinguish between imputed and original values.Additionally,we have devised an imputation filling technique that fully leverages the imputed data to enhance the imputation performance.Comparison experiments with several traditional imputation models demonstrate the superior performance of the ASTGAIN model across diverse missing scenarios.
基金This work was supported by the National Science Foundation[OAC-1835507 and IIP-1841520]。
文摘Big Earth data are produced from satellite observations,Internet-ofThings,model simulations,and other sources.The data embed unprecedented insights and spatiotemporal stamps of relevant Earth phenomena for improving our understanding,responding,and addressing challenges of Earth sciences and applications.In the past years,new technologies(such as cloud computing,big data and artificial intelligence)have gained momentum in addressing the challenges of using big Earth data for scientific studies and geospatial applications historically intractable.This paper reviews the big Earth data analytics from several aspects to capture the latest advancements in this fast-growing domain.We first introduce the concepts of big Earth data.The architecture,various functionalities,and supporting modules are then reviewed from a generic methodology aspect.Analytical methods supporting the functionalities are surveyed and analyzed in the context of different tools.The driven questions are exemplified through cutting-edge Earth science researches and applications.A list of challenges and opportunities are proposed for different stakeholders to collaboratively advance big Earth data analytics in the near future.
基金supported by National Natural Science Foundation of China[grant no U1811464]Graduate Inno-vation Fund Project of the Education Department of Jiangxi Province[grant no YC2022 B076]。
文摘Rich observation data generated by ubiquitous sensors are vital for wetland monitoring,spanning from the prediction of natural disasters to emergency response.Such sensors use different data acquisition and description methods and,if combined,could provide a comprehensive description of the wetland.Unfortunately,these data remain hidden in isolated silos,and their variety makes integration and interoperability a significant challenge.In this work,we develop a semantic model for wetland monitoring data using an agile and modular approach,namely,wetland monitoring ontology(WMO),which containsfive modules:wetland ecosystem,monitoring indicator,monitoring context,geospatial context,and temporal context.The proposed ontology supports the semantic interoperability and integration of wetland monitoring data from multiple sources,domains,modes,and spatiotemporal scales.We also provide two real-world use cases to validate the WMO and demonstrate the WMO’s usability and reusability.
