The measure of similarity of the building shape is crucial to the cartographic generalization process. Its research provides information on the contour of the building as a foundation for map analysis and the identification of spatial elements. Moreover, it is applied in many aspects, such as shape matching, shape retrieval, building simplification and building selection. With the development of neural networks, graph contrastive learning learns more discriminative representations by comparing positive samples from the same graph with negative samples from different graphs. Based on the advantages of the graph contrastive learning model,the study proposes a building shape similarity measurement model with the support of graph contrastive learning model, which aims to train a graph encoder to narrow the difference between positive samples and increase the gap between negative samples.The contrastive loss function and graph augmentation strategy are used to implement this operation. The following is the model's implementation process. Firstly, the vector building shapes are converted to the graph data structure and the point and edge features of the shapes are extracted.Secondly, two distinct views are generated as input to the encoder by applying various augmentation means, such as node dropping, edge removing, edge adding, and feature masking, to each graph. After that, the augmented graphs are then given to the graph encoder, which establishes each graph's feature encoding through the training process. Finally, the shape classification is achieved by a nonlinear classifier, and the extracted shape coding can be used to study shape similarities. The results indicated the shape classification accuracy of 96.7% using OSM shape data as training and testing samples. Furthermore, feature and node direction analysis, graph augmentation analysis, and parameter sensitivity analysis were carried out.The experimental results show that the classification accuracy rates of the HU moment method, Fourier method, and GCAE method are 22.9%, 44.4%, and 92.5%, respectively. Therefore, the method proposed in this paper outperforms traditional methods and deep learning in shape recognition capability.With a 95.7% shape classification accuracy, three areas of Hong Kong were chosen for shape matching and shape classification. And conducted shape matching tests on 9 typical shapes, finding that the similarity values of similar shapes were much greater than those of dissimilar shapes, consistent with visual perception.The graph contrastive learning model has effectively enhanced the recognition capability of complex shapes, providing technical support for applications such as cartographic generalization, spatial queries, shape matching, and shape retrieval.

[Significance] As a representative of new-quality productivity, the low-altitude economy is gradually emerging as a new engine for economic growth. This economy is based on the development and utilization of low-altitude airspace resources. While bringing development opportunities to geospatial information technology, it also poses entirely new challenges. [Progress and Analysis] In this paper, we introduce the division of low-altitude airspace resources and highlight typical drone application scenarios in the context of the low-altitude economy. Subsequently, we analyze the broad application prospects of geospatial information technology in key areas of the low-altitude economy, including the refined utilization of airspace resources, the construction of low-altitude environments, the planning, construction, and operation of new air traffic infrastructure, as well as the safe and efficient operation and regulatory oversight of drones. We emphasize that the geospatial information industry will benefit from development opportunities such as the integration and innovation of emerging scientific and technological advancements, growing market demand, policy support, industrial guidance, and industrial upgrading and transformation. [Prospect] Finally, we briefly address the challenges geospatial information technology must overcome to meet the development needs of the low-altitude economy. These include advancements in spatio-temporal dimension elevation, map and location-based services, high-frequency and rapid data acquisition systems, all-time and all-domain capabilities, and ubiquitous intelligent technologies. These areas will also serve as future directions for development and breakthroughs in geospatial information technology.

In the context of the rapid development of urbanization, the reasonable selection of locations for public service facilities is critical for delivering efficient services and enhancing the quality of urban residents' lives. However, prevailing approaches for allocation of public service facilities often fall short of meeting the demands on their performance and efficiency in complex and large-scale real-world scenarios. To address these issues, this article proposed a novel Graph-Deep-Reinforcement-Learning Facility Location Allocation Model (GDRL-FLAM), coupling a Facility Location Allocation Graph Attention Network (FLA-GAT) with a Deep Reinforcement Learning (DRL) algorithm. This proposed model tackled the location allocation problem for public service facilities based on graph representation and the REINFORCE algorithm. To assess the performance and efficiency of the proposed model, this study conducted experiments based on randomly generated datasets with 20, 50, and 100 points. The experimental results indicated that: (1) For the tests with 20, 50, and 100 points, the GDRL-FLAM model exhibited a significant improvement ranging from 11.79% to 14.49% compared to the Genetic Algorithm (GA) which is one of the commonly used heuristic algorithms for addressing location allocation problems. For the tests with 150 and 200 points, the improvement ranged from 1.52% to 9.35%. Moreover, with the increase in the size of the training set, the model also demonstrated enhanced generalizability on large-scale datasets; (2) The GDRL-FLAM model showed strong transfer learning ability to obtain the location allocation strategies in simple scenarios and adapt them to more complex scenarios; (3) In the case study of Singapore, the GDRL-FLAM model outperformed GA significantly, achieving obvious improvements ranging from 1.01% to 10.75%; (4) In all these abovementioned tests and experiments, the GDRL-FLAM model showed substantial improvement in efficiency compared to GA. In short, this study demonstrated the potential of the proposed GDRL-FLAM model in addressing the location allocation issues for public service facilities, due to its generalization and transfer learning abilities. The proposed GDRL-FLAM could also be adapted to solve other spatial optimization problems. Finally, the article discussed the limitations of the model and outlined potential directions for future research.

[Objectives] With the application of knowledge graph techniques in the field of Geographical Information Science (GIS), the Geographical Knowledge Graph (GeoKG) has become a key research direction. GeoKGs often lack sufficient geographic knowledge coverage, which can negatively impact downstream applications. Therefore, reasoning techniques are essential for GeoKG to complete missing knowledge, identify inconsistencies, and predict trends in geographic phenomena. Unlike reasoning techniques applied to general knowledge graphs, reasoning on GeoKGs must handle the unique and complex spatial and temporal characteristics of geographic phenomena. This paper comprehensively introduces and summarizes recent advances in GeoKG reasoning. [Analysis] First, it introduces the relevant concepts and problem definitions of GeoKG reasoning. Second, it analyzes the two core tasks of GeoKG reasoning: knowledge completion and prediction. The reasoning model for knowledge completion primarily fills gaps in the graph to ensure knowledge integrity, while the reasoning model for prediction aims to forecast future trends based on existing geographic data. These two models are optimized for different application scenarios, with different focuses in processing geographic data. [Prospect] Finally, the paper explores future development trends in GeoKG reasoning, highlighting areas such as processing complex relationships in spatiotemporal data, reasoning with multi-scale geographic knowledge, fusing multimodal data, and enhancing the interpretability and intelligence of reasoning models. Additionally, the integration of GeoKGs with large-scale pre-trained models is expected to become a key area of focus.

[Objectives] Forecasting is a key research direction in Geospatial Artificial Intelligence (GeoAI), playing a central role in integrating surveying, mapping, geographic information technologies, and artificial intelligence. It drives intelligent innovation and facilitates the application of spatial intelligence technologies across diverse real-world scenarios. [Progress] This study reviews the historical development of GeoAI-driven spatiotemporal forecasting, providing an overview of prediction models based on statistical learning, deep learning, and generative large models. In addition, it explores the mechanisms of spatiotemporal dependence embedding within these models and decouples general computational operators used for modeling temporal, spatial, and spatiotemporal relationships. [Prospect] The challenges faced by intelligent prediction models include sparse labeled data, lack of explainability, limited generalizability, insufficient model compression and lightweight design, and low model reliability. Furthermore, we discuss and propose four future trends and research directions for advancing geospatial intelligent prediction technologies: a generalized spatial intelligent prediction platform incorporating multiple operators, generative prediction models integrating multimodal knowledge, prior-guided deep learning-based intelligent prediction models, and the expansion of geospatial intelligent prediction models into deep predictive applications for Earth system analysis.

Urban green spaces are critical components of urban ecosystems, playing an irreplaceable role in improving the ecological environment and enhancing quality of life. High-precision identification of urban green spaces is fundamental for urban renewal and optimizing green infrastructure. However, research on the identification and spatial heterogeneity of green spaces in megacities remains relatively limited. This study, taking Xi'an as an example, integrates urban street view images and GF-2 (Gaofen-2) satellite imagery, employing methods such as ISODATA classification, K-Means classification, and convolutional neural networks to achieve multi-dimensional, downscaled, and high-precision identification and analysis of green spaces. The results indicate the following: (1) The K-Means classification method demonstrates significantly higher accuracy (84.5%) compared to the ISODATA classification method (62.4%) and more accurately maps the spatial characteristics and heterogeneity patterns of green spaces. The green space coverage identified by the K-Means method is 0.277 0, which is lower than the 0.360 7 identified by ISODATA. (2) The average Green View Index (GVI) of streets in Xi'an's main urban area is 0.156 0, indicating a generally good level of street greening. However, there is notable polarization across different roads, with 30% of sampling points having a GVI below 0.080 0. Overall, the GVI of higher-grade roads is greater than that of lower-grade roads, following the trend: primary roads > secondary roads > trunk roads > tertiary roads. (3) There is a positive correlation between the GVI of streets and the vegetation coverage in their surrounding areas in Xi'an's main urban area. However, this correlation weakens in certain road sections, reflecting differences between vertical cross-sections and overhead views of the streets. Combining these perspectives provides a more accurate assessment and quantification of urban green spaces. This study provides a reference for green space planning, green infrastructure construction, and smart management in Xi'an, as well as technical guidance for high-precision identification and spatial analysis of urban green spaces in other cities.

[Objectives] The geographic system is an integrated framework encompassing natural and human phenomena and their interrelationships on the Earth's surface. While Geographic Information Systems (GIS) can digitally process these geographic elements, they face challenges in addressing rapidly changing geographic contexts with complex 3D structures. This is primarily due to the lack of bi-directional interactions between physical and informational spaces, as well as their reliance on predefined rules and historical data. In this paper, we propose the concept of a “Geographic Intelligent Agent” as an advanced form of GIS, which integrates embodied intelligence, self-supervised learning, and multimodal language modeling to improve environmental perception, spatial understanding, and autonomous decision-making. [Methods] The architecture of the geographic intelligent agent consists of three core components: multimodal perception, an intelligent hub, and an action manipulation module. These components collectively acquire comprehensive environmental information through sensor networks, perform complex situatio reasoning using knowledge graphs and generative models, and enable real-time control and multilevel planning of the physical environment. To adapt to differences between virtual and real environments, the geographic intelligent agent is tested using the earth simulator and a test field platform, equipping it with stronger autonomous capabilities in complex and dynamic geographic contexts. [Results] This paper also demonstrates the implementation of geographic intelligent agent in spatial intelligence applications using the virtual digital human “EarthSage” as an example. [Conclusion] As a prototype of the geographic intelligent agent, "EarthSage" integrates modules such as the spatiotemporal Knowledge Ggraph (GeoKG) and a Cognitive Map Generation Model (GeoGPT), assisting users in obtaining intelligent spatial decision-making support in fields such as emergency management, urban planning, and ecological monitoring. This work exemplifies the transformation of GIS from a traditional information processing tool to an autonomous spatial intelligent system, marking a significant advancement in the field.

[Objectives] To systematically review recent advancements in text-to-image generation technology driven by large-scale AI models and explore its potential applications in urban and rural planning. [Discussion] This study provides a comprehensive review of the development of text-to-image generation technology from the perspectives of training datasets, model architectures, and evaluation methods, highlighting the key factors contributing to its success. While this technology has achieved remarkable progress in general computer science, its application in urban and rural planning remains constrained by several critical challenges. These include the lack of high-quality domain-specific data, limited controllability and reliability of generated content, and the absence of constraints informed by geoscience expertise. To address these challenges, this paper proposes several research strategies, including domain-specific data augmentation techniques, text-to-image generation models enhanced with spatial information through instruction-based extensions, and locally editable models guided by induced layouts. Furthermore, through multiple case studies, the paper demonstrates the value and potential of text-to-image generation technology in facilitating innovative practices in urban and rural planning and design. [Prospect] With continued technological advancements and interdisciplinary integration, text-to-image generation technology holds promise as a significant driver of innovation in urban and rural planning and design. It is expected to support more efficient and intelligent design practices, paving the way for groundbreaking applications in this field.

This paper addresses the challenge of discovering spatio-temporally associated vehicles involved in crimes using Automatic Number Plate Recognition (ANPR) data, which is a crucial resource in public security work for obtaining vehicle trajectories. The significance of identifying associated vehicles in the context of group-crime prevention and control is emphasized. Practical experiences reveal that criminal groups often adopt subjective strategies to avoid suspicion, leading to unique spatio-temporal association patterns such as intentional long-distance following, which differ from traditional accompanying relationships and are difficult to detect with existing methods. Oriented to the actual needs of public security work, from the perspective of group-crime, to tackle this issue, the paper first analyzes the travel patterns of criminal group vehicles and categorizes them into three main spatio-temporal association modes: close-following mode, intentional long-distance following mode, and alternative-route mode. These modes reflect the different strategies used by criminals to avoid detection, ranging from maintaining close proximity to the peer vehicle to deliberately choosing different routes. Based on these patterns, the paper develops a data model using ANPR data. The study introduces spatio-temporal constraint parameters to better capture the association relationships between vehicles. These parameters include the monitoring point time constraint (Δt_i), point accompanying number (Num_Wx), continuous point accompanying number (Con_Num_Wx), intermittent accompanying distance (d), and accompanying duration (δt).The proposed method for discovering spatio-temporally associated vehicles leverages these parameters to identify potential criminal associations. The methodology involves preprocessing ANPR data to obtain vehicle trajectories, extracting candidate accompanying vehicle sets, calculating spatio-temporal constraint parameters for each candidate vehicle, and setting thresholds for these parameters to discover associated vehicles containing different spatio-temporal patterns. Finally, taking city B as an example, the relevant ANPR data of group-crimes vehicles are used for test and analysis, and the spatio-temporal constraint parameter thresholds are quantitatively evaluated based on the historical data of group-crime cases, based on which the spatio-temporal correlation vehicle analysis of a typical case is conducted, and when comparing this paper's method with the two methods of frequent sequence mining and calculating the concomitant probability, the effectiveness of this paper's method can reach up to 87.59% on average, which is better than the the comparison methods. The results show that the method can effectively identify vehicles engaged in long-distance following and alternative-route strategies, which are often missed by traditional methods. As a result, it is able to quickly target those involved in the crime and further narrow the scope of investigation. In conclusion, the paper presents a comprehensive method for discovering spatio-temporally associated vehicles using ANPR data, significantly enhancing the ability to detect vehicles with complex association patterns. This method not only broadens the application scope of spatio-temporal association discovery but also provides new insights and technical support for public security departments in addressing group-crimes.

China is one of the countries most severely affected by geological disasters. Researching high-precision and highly reliable methods for monitoring and predicting landslide deformation holds practical significance for disaster prevention and mitigation efforts. Using the massive Outang landslide in the Three Gorges Reservoir Area as a case study, this paper addresses the issue of the atmospheric interference in extracting landslide deformation using time-series InSAR technology. To correct for atmospheric effects, the GACOS model is introduced and validated against GNSS observation data. To address the often-overlooked temporal-spatial analysis before landslide deformation prediction, the Moran index and Hurst index are calculated to analyze the spatiotemporal characteristics of landslide deformation. Recognizing that landslide deformation is influenced not only by historical deformation but also by various external factors, this paper proposes coupling landslide influencing factors with deformation data for prediction. A Long Short-Term Memory (LSTM) model, optimized by Variational Mode Decomposition (VMD) and the Sparrow Search Algorithm (SSA), is employed for the prediction. By decomposing landslide displacement data into trend, periodic, and random components using VMD, the LSTM network structure is constructed. SSA is used to determine the optimal number of hidden units, maximum training periods, and the initial learning rate of the LSTM model. Additionally, methods such as data normalization, regularization, and model evaluation are employed to enhance the performance and stability of the LSTM model. Finally, the model is trained using the influencing factors and decomposed displacement data to predict landslide deformation. The results indicate that: (1) From January 2021 to June 2023, the maximum and minimum deformation rates of the Outang landslide were -72.75 mm/a and 50.74 mm/a, respectively; (2) The deformation in the study area exhibits positive spatial autocorrelation, with the landslide in the settlement area showing a persistent trend; (3) The prediction error of the LSTM model optimized by VMD and SSA is only 0.37 mm, representing an 11.004% accuracy improvement compared to the standard LSTM model. Based on time-series InSAR technology and spatiotemporal analysis results, this paper constructs a high-precision prediction model for landslide deformation, incorporating multiple influencing factors. This model provides a valuable reference for the prevention and control of landslide disasters.

[Significance] Data resources have become pivotal in modern production, evolving in close synergy with advancements in artificial intelligence (AI) technologies, which continuously cultivate new, high-quality productive forces. Remote sensing data intelligence has naturally emerged as a result of the rapid expansion of remote sensing big data and AI. This integration significantly enhances the efficiency and accuracy of remote sensing data processing while bolstering the ability to address emergencies and adapt to complex environmental changes. Remote sensing data intelligence represents a transformative approach, leveraging state-of-the-art technological advancements and redefining traditional paradigms of remote sensing information engineering and its applications. [Analysis] This paper delves into the technological background and foundations that have facilitated the emergence of remote sensing data intelligence. The rapid development of technology has provided robust support for remote sensing data intelligence, primarily in three areas: the advent of the big data era in remote sensing, significant advancements in remote sensing data processing capabilities, and the flourishing research on remote sensing large models. Furthermore, a comprehensive technical framework is proposed, outlining the critical elements and methodologies required for implementing remote sensing data intelligence effectively. To demonstrate the practical applications of remote sensing data intelligence, the paper presents a case study on applying these techniques to extract ultra-high-resolution centralized and distributed photovoltaic information in China. [Results] By integrating large models with remote sensing data, the study demonstrates how remote sensing data intelligence enables precise identification and mapping of centralized and distributed photovoltaic installations, offering valuable insights for energy management and planning. The effectiveness of remote sensing data intelligence in addressing challenges associated with large-scale photovoltaic extraction underscores its potential for application in critical fields. [Prospect] Finally, the paper provides an outlook on areas requiring further study in remote sensing data intelligence. It emphasizes that high-quality data serves as the foundation for remote sensing data intelligence and highlights the importance of constructing AI-ready knowledge bases and recognizing the value of small datasets. Developing targeted and efficient algorithms is essential for achieving remote sensing intelligence, making the advancement of practical data intelligence methods an urgent research priority. Furthermore, promoting multi-level services for remote sensing data, information, and knowledge through data intelligence should be prioritized. This research provides a comprehensive technical framework and forward-looking insights for remote sensing data intelligence, offering valuable references for further exploration and implementation in critical fields.

In high-resolution remote sensing images, challenges such as blurred visual features of objects and different spectra for the same object arise. Segmenting similar ground objects and shaded ground objects in a single mode is difficult. Therefore, this paper proposes a remote sensing image segmentation model based on multi-modal feature extraction and hierarchical perception. The proposed model introduces a multi-modal feature extraction module to capture feature information from different modalities. Using the complementary information of IRRG and DSM, accurate pixel positions in the feature map are obtained, improving semantic segmentation of high-resolution remote sensing images. The coordinate attention mechanism fully fuses the features from different modalities to address issues of blurred visual features and different object spectra during image segmentation. The abstract feature extraction module uses MobileNetV3 with dual-path bottleneck blocks as the backbone network, reducing the number of parameters while maintaining model accuracy. The hierarchical perception network is introduced to extract deep abstract features, and the attention mechanism is improved by embedding scene perception of pixels. Leveraging the inherent spatial correlation of ground objects in remote sensing images, efficient and accurate class-level context modeling is achieved, minimizing excessive background noise interference and significantly improving the semantic segmentation performance. In the decoding module, the model uses multi-scale aggregation dual fusion for feature recovery, strengthening the connection between the encoder and the decoder. This combines low-level features with high-level abstract semantic features, enabling effective spatial and detailed feature fusion. Progressive upsampling is used for feature recovery, resolving the issue of blurred visual features and improving segmentation accuracy. Based on high-resolution remote sensing images from the ISPRS Vaihingen and Potsdam datasets, the experimental results demonstrate that MFEHPNet outperforms a series of comparison models, including C3Net, AMM-FuseNet, MMFNet, CMFet, CIMFNet, and EDGNet, across various performance indicators. In the ISPRS Vaihingen and Potsdam datasets, MFEHPNet achieves an overall accuracy of 92.21% and 93.45%, an average intersection ratio of 83.24 % and 83.94 %, and a Kappa coefficient of 0.85. The frequency-weighted intersection ratio is 89.24 % and 90.12%, respectively, significantly improving the semantic segmentation performance of remote sensing images and effectively addressing the issues of blurred feature boundaries and different spectra during segmentation.

Road selection has always been a significant research aspect of cartographic generalization, which is of great significance for spatial data linkage updating and multi-scale representation. The existing selection methods mainly include those based on stroke, semantic information, graph theory, road density, and artificial intelligence, but they only consider the features of a single level selection unit. Therefore, this paper proposes an automatic road selection method that integrates road segment and stroke features. Firstly, the road segment and stroke are used as basic units to construct a dual graph representing the spatial structure of the road network. Based on this, feature calculations are performed: length, degree, closeness centrality, betweenness centrality, and hierarchy are considered as road segment features, while length, the number of containing road segments, and the number of connections of road segment under the same stroke are regarded as stroke features. These stroke features are then integrated into the corresponding road segment unit. The obtained feature matrix is input into the GraphSAGE model for learning, which outputs the classification result of road segment. Finally, a method that increases the minimum number of nodes while considering stroke coherence is utilized to maintain the connectivity of the road network, thereby completing the road selection. Experiments were conducted using 1:250 000 and 1:500 000 scale road network data from Zhengzhou, Henan Province. The results indicate that the proposed method effectively integrates the features of road segments and strokes, overcoming the limitations of using a single road segment or stroke as the selection unit. Compared to the method in reference 17 and the comparative methods that use a road segment or stroke as the selection unit, the model's prediction accuracy improved by 6.36%, 7.36% and 3.13%, respectively. The results processed by the proposed connectivity preservation algorithm were more in line with the cognitive rules of road selection and could further improve the accuracy of selection. After connectivity processing, the proposed method improved the consistent road length by 125.45 km and 110.438 km, and the proportion of consistent road numbers by 8.72% and 20.43%, respectively, while better maintaining the overall and local key structures and density distribution of the road network. Compared with existing road selection methods, this method can better utilize multi-level road features to improve the effectiveness of road selection, providing a new approach for subsequent research in areas such as cartographic generalization and linkage updating.

Scientific and accurate monitoring of mangroves is the basis and premise for protecting marine coastal wetland ecosystems. Multi-source remote sensing data can be used to classify mangrove species effectively, but challenges remain in applying optical and SAR image features along with their time-varying information. In this paper, based on Sentinel-1/2 image data, we propose a mangrove species classification framework using Multi-source Features-coupled and Ensemble Learning algorithm (MFEL). The framework analyzs the classification advantages of spectral index features, SAR polarization features, and their temporal harmonic spectral features in feature selection and coupling. It then stacks the Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) models to construct an Ensemble Learning model for mangrove species classification. Comparing the RF classification model and XGBoost models based on feature optimization, we evaluated the classification accuracy and feature application differences of the MFEL classification method. Zhanjiang Mangrove Forest National Nature Reserve was selected as the experimental area. The results show that: ① compared to using only spectral index features, classification accuracy improves by 6% and 8% with the addition of SAR polarization features or temporal harmonic spectral features, respectively. Adding both SAR polarization features and temporal harmonic spectral features simultaneously improves classification accuracy by 12%, making it more effective for mangrove species classification. ② The MFEL method achieves the highest classification accuracy, with an overall accuracy of 88.03% and a Kappa coefficient of 0.86. When the MFEL model trained on samples from the experimental area was applied to other areas, the classification accuracies were 83.94% and 82.77%, respectively. ③ This study verifies the potential application of SAR polarization features and time-sequence harmonic spectral features in mangrove species classification, significantly improving the accuracy for five mangrove species, with accuracies ranging from 76% to 91%. The study results provide valuable insights for expanding the use of medium-resolution remote sensing satellite imagery in monitoring mangrove species.

Tree shade is an important resources for mitigating the effects of extreme heat in urban areas. Quantifying the extent of tree shade resources can assist in the prediction and risk assessment of high temperatures in cities. Among the existing methods for estimating tree shade resources, the measured method is time-consuming and ineffective, while the image identification method is difficult to accurately respond to the spatial and temporal changes of tree shade. In this paper, a method was proposed for simulating and quantifying tree shade based on a three-dimensional(3D) scene. We simulated the urban street scene by employing 3D reconstruction technology, distinguished different geographic entity models, utilising the sun's geometric position parameter and construct the corresponding lighting environment, and the shade in 3D scene was simulated according to the principle of linear propagation of light and shadow. The formation of tree shade is determined through the use of a ray intersection algorithm, which allows for the differentiation of sun rays within a 3D model of the shading situation. This process enables the generation and classification of tree shade, which can then be distinguished from shadows cast by their features. The attributes of tree shade (e.g., shade area and shade coverage duration facilitates)can be quantified and visualized in the 3D scene for intuitive representation. A comparison and verification of the shadows taken by the Unmanned Aerial Vehicle(UAV). The results of relative error range from 3.35% to 13.27%, with an average relative error of 9.29%. This method is potential for the estimation of shade tree resources. In addition, a case of shade resources of trees in an urban street scene was simulated and quantified, taking into account their spatial orientation, species and life cycle. The method enables the simulation of the spatial and temporal distribution of shadow resources for real and virtual scenarios (both future and planned) at any given moment. It can be classified and counted, thereby providing the potential service for urban planning and management, as well as fundamental data for the analysis of the cooling effects of urban trees.

The timely identification of potential criminal travel routes of key surveillance individuals is a crucial research focus for public security early warning systems. Current studies often concentrate on the travel patterns and destination preferences of criminals, but there is a lack of research from the criminals’ perspective, considering the built environment and road network structure to analyze their criminal travel routes. To address this gap, a spatiotemporal analysis approach is proposed, considering criminals’ cognition of concealment. Based on the principles of criminal psychology and rational choice theory, this paper categorizes the travel patterns of criminals under the cognition of concealment into two principles: "the Principle of Minimal Exposure Risk" and "the Principle of Minimal Travel Cost". Firstly, the urban perceptual elements within a criminal's perceptual range, including safety and risk perception elements that bring exposure risks, are calculated and introduced into the choice degree model. The "Criminal Choice Degree of Roads" is proposed to measure the optimal local roads within a criminal's perceptual range. Next, using the "Length of the Route Already Traveled" as the cost function and the "Criminal Choice Degree of Roads" within the perceptual range as the heuristic function, an improved heuristic algorithm is employed to calculate the overall optimal criminal travel route. Finally, from the perspective of crime prevention and control, experiments are conducted to analyze the distribution of urban road choice degrees and the criminal travel routes of key personnel. By comparing the routes obtained by this method with those derived from existing methods and actual criminal travel routes, it is shown that the routes calculated by this proposed method are more reasonable. They are more likely to be chosen by criminals for concealment and have relatively short travel distances, without long-term exposure in public areas. The routes, in terms of distance, travel time, and the urban perceptual elements they pass through, are closer to the actual travel behaviors of criminals, verifying the rationality of this method. The research conclusion provides decision support for public security early warning efforts, emphasizing the importance of balancing travel distance and exposure risk when monitoring key personnel, and the need to allocate resources based on the distribution of urban perceptual elements and road networks to enable timely and accurate crime prevention and interception.

[Significance] As a comprehensive observation of natural resource development and utilization, spatio-temporal big data on natural resources contains valuable knowledge about resource distribution, spatio-temporal process evolution, and interrelationships. [Progress] This paper examines spatio-temporal big data mining and knowledge services for natural resources, highlighting key data mining techniques and their critical applications in knowledge services. First, it introduces the core concepts, technical frameworks, and methodological processes of spatio-temporal clustering analysis, association mining, anomaly detection, predictive modeling, and geographic risk assessment, along with their applications in natural resource management and land-use decision-making. Second, a four-tier natural resource spatio-temporal knowledge service system is proposed, encompassing descriptive, diagnostic, predictive, and decision-making knowledge services, which provide essential support for applications such as resource status monitoring, land-use regulation, and disaster prevention and mitigation. Finally, the paper indicates that current natural resource management is transitioning from data aggregation and analysis to knowledge-driven intelligent services, forming an emerging research and application paradigm of big data, big analysis, big knowledge, and big services. [Prospect] Future efforts will focus on advancing collaborative data and knowledge mining technologies, addressing the standardization challenges in spatio-temporal knowledge bases and services, and exploring the potential of cutting-edge technologies such as generative large models in the natural resource domain to drive the information and intelligent transformation of natural resource management.

[Objectives] With the development of deep learning technology, the ability to monitor changes in natural resource elements using remote sensing images has significantly improved. While deep learning change detection models excel at extracting low-level semantic information from remote sensing images, they face challenges in distinguishing land-use type changes from non-land-use type changes, such as crop rotation, natural fluctuations in water levels, and forest degradation. To ensure a high recall rate in change detection, these models often generate a large number of false positive change polygons, requiring substantial manual effort to eliminate these false alarms. [Methods] To address this issue, this paper proposes a natural resource element change polygon purification algorithm driven by remote sensing spatiotemporal knowledge graph. The algorithm aims to minimize the false positive rate while maintaining a high recall rate, thereby improving the efficiency of natural resource element change monitoring. To support the intelligent construction and effective reasoning of the spatiotemporal knowledge graph, this study designed a remote sensing spatiotemporal knowledge graph ontology model taking into account spatiotemporal characteristics and developed a GraphGIS toolkit that integrates graph database storage and computation. This paper also introduces a vector knowledge extraction method based on the native spatial analysis of the GraphGIS graph database, a remote sensing image knowledge extraction method based on efficient fine-tuning of the SkySense visual large model, and a polygon purification knowledge extraction method based on the SeqGPT large language model. Under the constraints of the spatiotemporal ontology model, vector, image, and text knowledge converge to form a remote sensing spatiotemporal knowledge graph. Inspired by the manual operation methods for change polygon purification, this paper developed an automatic purification method of change polygons based on first-order logical reasoning within the knowledge graph. To improve the concurrent processing and human-computer interaction, this paper developed a remote sensing spatiotemporal knowledge graph management and service system. [Results] For the task of purifying natural resource element change polygons in Guangdong Province from March to June 2024, the proposed method achieved a true-preserved rate of 95.37% and a false-removed rate of 21.82%. [Conclusions] The intelligent purification algorithm and system for natural resource element change polygons proposed in this study effectively reduce false positives while preserving real change polygons. This approach significantly enhances the efficiency of natural resource element change monitoring.

Scientific knowledge of the spatio-temporal evolution processes and formation mechanisms of territorial space in countries along the Central Asia-West Asia Economic Corridor holds significant scientific value and practical importance for supporting the current "Going Global" strategy and the "Belt and Road" initiative. Based on the dominant functions of the territories, the Central Asia-West Asia Economic Corridor is divided into three major types of territorial space: urban and rural construction, agricultural production, and ecological protection. A long-term analysis base map of territorial space from 2002 to 2022 was constructed by integrating multi-source spatio-temporal data. The spatio-temporal cube model was employed to depict the spatio-temporal evolution processes and typical patterns, while the integrated spatial transformation intensity model analyzed the characteristics of spatial structural transformation across three dimensions: scale, location, and intensity. The VIVI-SHAP framework of an interpretable machine learning model was used to analyze the evolution mechanisms, focusing on the importance of driving factors, interaction intensity, and non-linear dependencies. The results show that: (1) Approximately 6.14% of the territorial space in countries along the corridor underwent structural transformation over the past 20 years. The proportion of urban and rural construction space, though small, increased steadily by 0.17%, while agricultural production space decreased by 19.04% overall, with significant structural changes within the ecological protection space. (2) The dynamic interchange between green and other ecological spaces within the ecological protection space is predominant, with a systematic tendency for green ecological space to convert into agricultural production space, while the main source of urban and rural construction space expansion was green ecological space, accounting for 56.36% of the total converted area. 3) The territorial spatial pattern of the corridor is shaped by multiple processes of territorial space transformation, each with different magnitudes, intensities, and driving mechanisms. Natural geographic factors and transportation location factors played decisive roles, while the global influence of population growth and socio-economic development on territorial space structural transformation was less pronounced. This study provides new perspectives and methods to reveal the patterns and mechanisms of changes in land spatial types in the Central Asia-West Asia region. It further provides data support for decision-making departments to formulate reasonable land spatial planning, and demonstrates its application value in achieving greater spatial comprehensive benefits and promoting coordinated regional economic development.

Enhancing and sustaining urban competitiveness is contingent upon the presence of urban vitality. Urban planners and managers face increasing pressure to find more accurate and logical ways to manage urban development due to the growing challenges associated with municipal government. This study focuses on the central region of Nanjing. A detailed framework for evaluating urban vitality is proposed from three perspectives, human activities, network interactions, and the physical environment. This framework uses foundational road networks and building footprints from the World Map, Baidu heatmap, Dianping restaurant data, social media check-in data, Baidu Map POI, and innovation data. To create a comprehensive vitality evaluation framework, nine urban vitality indicators were reduced in dimensionality using the real-coded accelerated genetic algorithm based on the Projection Pursuit Model (RAGA-PPM). An analysis was also conducted on the differences with EWM and the spatial distribution patterns of both unidimensional and comprehensive vitality in Nanjing. The conclusions can be divided into three parts. First, the spatial distribution pattern of vitality in Nanjing's central urban area is successfully reflected by the comprehensive evaluation technique based on multi-source big data. The validity of the proposed evaluation system was confirmed by analyzing vitality cluster sample locations. Second, similar spatial features may be seen in Nanjing's unidimensional vitality, revealing a monocentric urban structure, with high-value areas gradually decreasing outward from the Xinjiekou commercial district. Commercial districts and metro stations are the focal points of population activity vitality, with each district exhibiting strong central values and secondary vitality clusters. Urban vitality values decline, with the Xinjiekou commercial area and Nanjing South Station serving as hubs of network interaction vitality. Urban vitality ratings decrease concentrically, with the Xinjiekou commercial area and Nanjing South Station serving as the hubs of network interaction vitality. Physical building vitality is geographically scattered, with high and relatively high values spread across most areas. Third, unidimensional vitality is not unfamiliar to comprehensive vitality. Additional viable centers for vitality were identified, with each district having a vitality hub. Xuanwu, Gulou, Jianye, and Qinhuai districts, which comprise the old city, form the core of Nanjing's vibrancy and serve as significant hubs. Liuhe and Yuhuatai districts have the lowest vitality, while Xuanwu and Qinhuai districts show the highest vitality. Most districts with above-average comprehensive vitality scores are located near transportation hubs, university areas, industrial parks, pedestrian streets, and commercial centers. According to the study, urban designers may benefit from a more thorough and multifaceted understanding of urban vitality patterns.

Addressing the issue of Ultra-Wideband (UWB) signal obstruction by obstacles in indoor environments, which leads to Non Line of Sight (NLOS) errors, this paper presents a fusion positioning method based on Light Detection And Ranging (LiDAR) point cloud for identifying UWB NLOS. This method utilizes LiDAR point cloud information to assist in the identification of UWB NLOS and leverages UWB Line of Sight (LOS) ranging values to eliminate cumulative errors in the LiDAR Simultaneous Localization and Mapping (SLAM) positioning process, thereby enhancing the accuracy and robustness of indoor fusion positioning. Initially, the method processes the LiDAR point cloud using an octree, constructs the ranging direction based on the location information of UWB base stations, and extracts the relevant point cloud data in the ranging direction from the LiDAR point cloud. Subsequently, the 3D Alpha Shape algorithm is employed to extract contours of obstacles that may hinder UWB signal propagation within the extracted point clouds. Furthermore, by analyzing the spatial relationship between the extracted obstacle contours and the UWB ranging direction, the presence of NLOS conditions in UWB signals is effectively determined. Finally, NLOS ranging values identified during the UWB ranging process are excluded, and a tight integration approach is used with an Extended Kalman Filter (EKF) to fuse UWB LOS ranging values with LiDAR SLAM positioning data, eliminating cumulative errors in the LiDAR SLAM positioning outcomes, thereby enhancing the precision and robustness of fusion positioning. Experimental results demonstrate that this method significantly improves positioning accuracy in indoor environments, increasing the positioning accuracy by 96.13% compared to the positioning method that tightly combines the original UWB ranging values with LiDAR SLAM using EKF, with a positioning error of 0.067 m, achieving sub-meter level indoor positioning accuracy.

[Objectives] The outdoor pedestrian navigation road network is a vital component of maps and a crucial basis for outdoor activity route planning and navigation. It plays a significant role in promoting outdoor travel development and ensuring safety management. However, existing research on road network generation mainly focuses on the construction of urban vehicular navigation networks, with relatively less emphasis on hiking navigation road networks in complex outdoor environments. Moreover, existing methods primarily emphasize the extraction of two-dimensional geometric information of roads, while the reconstruction of real three-dimensional geometric and topological structures remains underdeveloped. [Methods] To address these limitations, this study proposes a method for constructing the three-dimensional outdoor pedestrian navigation road network maps using crowdsourced trajectory data. This approach leverages a road network generation layer and an elevation extraction layer to extract the two-dimensional structure and three-dimensional elevation information of the road network. In the road network generation layer, a trajectory density stratification strategy is adopted to construct the two-dimensional vector road network. In the elevation extraction layer, elevation estimation and optimization are performed to generate an elevation grid raster map, which is then matched with the two-dimensional road network to produce the three-dimensional hiking navigation road network. [Results] To demonstrate the effectiveness of the proposed approach, experiments were conducted using 1 170 outdoor trajectories collected in 2021 from Yuelu Mountain Scenic Area in Changsha through an online outdoor website. The constructed outdoor three-dimensional hiking road network map achieved an average positional offset of 4.201 meters in two-dimensional space and an average elevation estimation error of 7.656 meters. The results demonstrate that the proposed method effectively handles outdoor trajectory data with high noise and varied trajectory density distribution differences, generating high-quality three-dimensional hiking road network maps. [Conclusions] Compared to traditional outdoor two-dimensional road networks, the three-dimensional navigation road networks constructed this study provide more comprehensive and accurate map information, facilitating improved pedestrian path planning and navigation services in complex outdoor environments.

The monitoring of coastal natural and constructed wetlands is of great importance to the protection of coastal water environment and natural resources. In practice, dynamic ranges of coastal natural and constructed wetlands can be monitored by using satellite image synthesis to represent the processes of wetlands being affected by dynamic changes in tidal levels. They can also be achieved by developing remote sensing indexes that are effective in characterizing natural wetlands exhibiting certain spectrum characteristics and by using advanced numerical algorithms that are capable of segmenting constructed wetlands showing some distinct boundaries. Based on multi-source remote sensing and ground data, this paper has presented a novel method to extract natural and constructed wetlands by combining unsupervised and supervised classification methods. Specifically, based on the Landsat images on the Google Earth Engine (GEE) cloud platform, the Inundated Mangrove Forest Index (IMFI) and related indexes are derived as the characteristic variables for the Random Forest (RF) algorithm; the slope obtained from elevation is also used to reduce the misclassification of mangrove forests since the majority of mangrove forests tends to be distributed in areas with gentle topography; and furthermore the K-means clustering algorithm is used to automatically extract wetlands without morphological processing. Through the case study of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA), the metrics of Producer's Accuracy (PA), User's Accuracy (UA), Overall Accuracy (OA) and Kappa coefficient are used to verify the effectiveness of the method through applications to long-term satellite images. The results show that: (1) Compared with other indexes, the IMFI can more effectively identify water, aquaculture ponds and tidal flats; (2) By combining the K-means clustering algorithm with the IMFI, the distinctions between wetland classes and between wetlands and other ground objects can be enhanced by segmenting constructed wetland and clustering tidal flats; (3) The average OA of the extraction method in the classification of coastal areas in the GBA over the past 34 years is 89.23% and the average Kappa coefficient is 0.873 1. The method can effectively solve the problems of misclassification and omission between wetland classes and between wetlands and water, with the accuracy slightly fluctuating over time. In the meantime, this method circumvents the influences of subjective threshold selection and is not limited to local and regional spatial scales. Taken together, the proposed method can provide technical supports for high-precision dynamic monitoring and early warning for the protection of coastal natural and constructed wetlands.

Bicycle sharing offers the advantages of resource sharing, environmental sustainability, and low carbon emissions, and has been widely applied in recent years. Trajectory prediction of shared bicycles is crucial for the scientific and efficient planning of infrastructure. However, existing trajectory prediction mechanisms are relatively limited, and the influencing factors are often too narrow, leading to low prediction accuracy. This restricts the further growth and development of bicycle-sharing systems. Therefore, accurately predicting the travel trajectories of shared bicycles is essential for optimizing bicycle lanes, efficiently deploying and scheduling bicycle resources, improving road design, and addressing the "last mile" challenge in urban transportation. To better understand the spatio-temporal characteristics of shared bicycle travel and the influence of natural and weather factors on travel trajectories, and to improve prediction accuracy, this paper developes a trajectory prediction model that integrates natural and weather factors with a spatio-temporal attention residual bi-directional network (NWSTAR-BiLSTM). This study uses shared bicycle order and trajectory data from Xiamen, provided by the government’s open data platform, to analyze the spatio-temporal distribution of travel and the impact of natural and weather factors on trajectories. The model incorporates variables such as temperature, weather conditions, wind speed, and air quality, dividing the shared bicycle trajectory data into time series based on periodicity. Using an attention mechanism and residual learning, the prediction results are adjusted according to weather factors. The dataset is divided into training, testing, and validation sets in a 7:2:1 ratio, and the model undergoes training, parameter adjustment, and comparative validation. Experimental results show that the trajectory prediction accuracy of the NSTARWSTAR-BiLSTM model exceeds that of traditional models, such as LSTM, BiLSTM, CNN, Att-LSTM, and self-built comparative models (e.g., STAR-BiLSTM without natural and weather factors, WSTR-BiLSTM without the attention mechanism, and WSTA-BiLSTM without the residual network). The NSTARWSTAR-BiLSTM model not only inherits the strengths of traditional residual network models but also innovatively integrates the attention mechanism with multiple natural and weather factors, enhancing trajectory prediction accuracy. The model also demonstrates strong intelligent learning capabilities, with prediction accuracy improving as feedback increases.

Due to the imbalanced regional development, data scarcity exists in some regions, which to some extent restricts the progress of spatial prediction research. The introduction of cross-area knowledge transfer offers a valuable method for mitigating the impact of data scarcity in areas with limited samples and for conducting spatial prediction. With technological advancements, spatial prediction methods based on transfer learning and the Third Law of Geography have become mainstream in the fields of computer science and geography. Transfer learning techniques leverage knowledge from a source domain with abundant data to solve related tasks in a target domain with limited data. Meanwhile, the proposal and application of the Third Law of Geography show that by comparing the similarity of geographical environmental variables between sampled regions and unsampled regions (rather than relying solely on traditional spatial distance or quantitative relationships), it is possible to predict target information in unsampled regions using a small amount of sample data. This provides a theoretical basis and methodological reference for selecting the source domain and target domain in cross-regional knowledge transfer. This paper conducts a literature review of cross-regional spatial prediction research based on these two major methods since 2018, focusing on the following key tasks: (1) Comparing and analyzing the basic principles of spatial prediction based on geographical similarity and transfer learning, and identifying differences in their technical procedures; (2) Summarizing the differences in similarity representation indicators and measurement methods between the two approaches; (3) Examining differences in commonly used auxiliary data, spatial analysis units, modeling methods, and evaluation indicators between the two prediction methods; (4) Discussing the challenges and limitations faced by these cross-regional knowledge transfer methods. The study shows that while the technical principles of both methods are basically consistent, they have specific limitations regarding their scope of application, similarity representation and measurement, relevant auxiliary variables, and parameter selection. The research offers useful insights for optimizing and improving these methods, integrating them effectively, innovating cross-regional prediction approaches, and expanding their application fields.

[Objectives] Ship detection using Synthetic Aperture Radar (SAR) images has gained widespread recognition and application across various fields, including marine search and rescue, port reconnaissance, and territorial sea defense. Nevertheless, with the rapid advancement of on-orbit intelligent processing technologies, higher demands have emerged for real-time detection of ship targets in spaceborne SAR images. [Methods] To address challenges such as the diverse scales of ship targets in current SAR images, the complex background of shore-based vessels, and the limited hardware resources of various remote sensing platforms, this paper presents a lightweight SAR image ship detection model, LWM-YOLO. Firstly, we propose a Lightweight Backbone Network (LWCA) designed specifically for SAR image processing. The LWCA integrates an optimized backbone network with an attention mechanism, effectively reducing the model's complexity and parameter size while maintaining high performance and lowering computational demands. Secondly, to tackle the issue of diverse target scales in SAR images, we have constructed a lightweight feature fusion module, termed LGS-FPN. This module enhances the extraction of detailed information on ship targets in SAR images by efficiently fusing features from different scales, improving detection performance for ship targets of various sizes. Furthermore, the module minimizes computational complexity, ensuring that the model can operate smoothly without significant resource consumption. In addition to addressing the scale issue, we have also focused on optimizing localization accuracy. We introduce a detection architecture based on the MPD-Head, which leverages the strengths of the MPD-Head to improve detection performance for small ship targets in complex environments. Finally, we validate the proposed algorithm through comparative experiments with mainstream methods on the LS-SSDD and SSDD ship detection datasets. [Results] The results demonstrate that our algorithm achieved mean Average Precision (mAP) values of 74.7% and 97.3% on the respective datasets, representing improvements of 1.5 and 1.0 percentage points over the baseline model. Additionally, the parameter size of our model was reduced to 36% of the baseline model, and computational complexity decreased to 80%. [Conclusions] Compared to other mainstream algorithms, the proposed method demonstrates not only higher accuracy but also significant advantages in detection speed. These findings can provide robust support for intelligent target detection, space-based in-orbit applications, and related fields.

Existing digital fingerprinting algorithms for vector geographic data predominantly utilize symmetric digital methods. In these algorithms, both merchant and buyer possess data containing fingerprints, which poses a significant challenge in determining responsibility for data leakage when illegal copies are found. If illegal copies are discovered, it becomes difficult to ascertain whether the merchant or the buyer is at fault. Moreover, there is a risk of merchants falsely accusing legitimate buyers or illegal buyers evading accusation. This scenario can lead to disputes and undermine trust in the data distribution process. To address this issue, this paper proposes an asymmetric fingerprint protocol for vector geographic data based on homomorphic encryption. The protocol begins with the buyer generating a unique fingerprint, which is then encrypted using the buyer's public key and sent to the merchant. Next, the merchant selects a portion of the vector geographic data and encrypts it using the buyer's public key. The Paillier homomorphic encryption scheme, known for its additive homomorphic properties, is employed here, allowing the merchant to embed the encrypted buyer's fingerprint directly into the encrypted geographic data. Simultaneously, the merchant embeds their own fingerprint into the unencrypted portion of the data. This dual-fingerprint embedding ensures that the data contains both the buyer’s and the merchant's fingerprints while maintaining the confidentiality of the buyer's fingerprint. After embedding both fingerprints, the merchant sends the resultant encrypted data back to the buyer, who then decrypts the data using a private key to obtain the plaintext version containing both fingerprints. This process ensures that the buyer receives the data with both fingerprints embedded, while the merchant is unable to view or misuse the buyer's fingerprint. The use of homomorphic encryption in this protocol offers several advantages. First, it prevents the merchant from obtaining the buyer's fingerprint in plaintext form, thereby eliminating the risk of the merchant embedding the buyer's fingerprint into other datasets to frame the buyer. Second, the protocol allows the merchant to verify the presence of the buyer's fingerprint in the data without revealing the fingerprint itself, facilitating infringement tracking. Moreover, the protocol is designed to withstand various types of attacks. Experimental results indicate that the fingerprint sequence can still be accurately extracted even after multiple attacks, demonstrating the robustness of the system. In the event of a dispute, the arbitration process is designed to be secure and unbiased. The protocol ensures that neither the buyer nor the merchant needs to disclose sensitive key information to a third party. Instead, the third party can conduct the arbitration without accessing the underlying private information, preventing any collusion that could harm the interests of either party. This approach ensures fair resolution while maintaining the confidentiality and integrity of the involved parties.