Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105075
Yan Zhou , Xianwei Zheng , Jinding Gao , Qian Shi , Xiaoping Liu
Efficient and effective pose estimation and 3D point clouds reconstruction from low-altitude UAV images is crucial for digital twins and geospatial applications. However, conventional divide-and-conquer SfM pipelines remain constrained by the high computational cost of incremental reconstruction. While global SfM, though faster, often suffer from instability due to outlier sensitivity in translation averaging. To address these limitations, we propose a feature track enhanced global SfM within divide-and-conquer framework. To deal with outliers, a cluster consistency constrained outlier filtering method is proposed, which combines distribution-aware scene partition and cluster consistency to remove false matches. Furthermore, we propose a geometry-constrained alignment optimization strategy in sub-models merging process to eliminate misalignments and ghosting artifacts, obtaining complete and accurate 3D models. Extensive experiments on ETH3D and SYSU UAV large-scale datasets verify that the proposed method outperforms established baselines, with comparable accuracy to the incremental SfM but half of the computation time. The reconstructed 3D models demonstrate notable enhancements in both structural integrity and level of detail, proving the method’s high applicability in large-scale 3D reconstruction tasks. The code and data will be released: https://github.com/BunnyanChou/HieGSfM.
{"title":"A geometric consistency constrained hierarchical global SfM for large-scale UAV images","authors":"Yan Zhou , Xianwei Zheng , Jinding Gao , Qian Shi , Xiaoping Liu","doi":"10.1016/j.jag.2025.105075","DOIUrl":"10.1016/j.jag.2025.105075","url":null,"abstract":"<div><div>Efficient and effective pose estimation and 3D point clouds reconstruction from low-altitude UAV images is crucial for digital twins and geospatial applications. However, conventional divide-and-conquer SfM pipelines remain constrained by the high computational cost of incremental reconstruction. While global SfM, though faster, often suffer from instability due to outlier sensitivity in translation averaging. To address these limitations, we propose a feature track enhanced global SfM within divide-and-conquer framework. To deal with outliers, a cluster consistency constrained outlier filtering method is proposed, which combines distribution-aware scene partition and cluster consistency to remove false matches. Furthermore, we propose a geometry-constrained alignment optimization strategy in sub-models merging process to eliminate misalignments and ghosting artifacts, obtaining complete and accurate 3D models. Extensive experiments on ETH3D and SYSU UAV large-scale datasets verify that the proposed method outperforms established baselines, with comparable accuracy to the incremental SfM but half of the computation time. The reconstructed 3D models demonstrate notable enhancements in both structural integrity and level of detail, proving the method’s high applicability in large-scale 3D reconstruction tasks. The code and data will be released: <span><span><u>https://github.com/BunnyanChou/HieGSfM</u></span><svg><path></path></svg></span>.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105075"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105030
Adeel Ahmad , Srikumar Sastry , Aayush Dhakal , Subash Khanal , Alex Levering , Hammad Gilani , Nathan Jacobs
The western Himalayas in Pakistan, characterized by a diverse range of conifer species at higher elevations, represent a critical biodiversity hotspot and habitat for numerous species. Accurate spatial assessments of canopy height are essential for improving estimates of aboveground biomass, carbon sequestration, and associated forest ecosystem services in this region. In this study, we estimated canopy heights in the western Himalayas in Pakistan using a U-Net CNN approach, fusing data from the Global Ecosystem Dynamics Investigation Mission (GEDI) with multi-band Sentinel-2 (S2) imagery. We produced a canopy height map at a 10 m resolution for 2020. To ensure accurate measurements across various canopy height groups, we implemented a stratified training approach that optimized the representation of GEDI data throughout the training, validation, and testing phases. We trained multiple models using varying thresholds and assigned different weights to taller trees to improve accuracy between different canopy height groups in the study region. Our best model achieved a Root Mean Square Error (RMSE) of 7.52 m and a Mean Absolute Error (MAE) of 5.71 m in the test set, significantly outperforming existing global canopy height models in this topographically complex region. We further validate our predictions against field inventory plots, achieving a coefficient of determination (R) of 0.49 for plots containing at least 15 trees. The resulting tree canopy height map, designated as the Western Himalaya Canopy Height Map (WHiCH Map), is publicly available.
{"title":"Canopy height mapping in the Western Himalayas, Pakistan: A deep learning approach using GEDI and Sentinel-2 fusion","authors":"Adeel Ahmad , Srikumar Sastry , Aayush Dhakal , Subash Khanal , Alex Levering , Hammad Gilani , Nathan Jacobs","doi":"10.1016/j.jag.2025.105030","DOIUrl":"10.1016/j.jag.2025.105030","url":null,"abstract":"<div><div>The western Himalayas in Pakistan, characterized by a diverse range of conifer species at higher elevations, represent a critical biodiversity hotspot and habitat for numerous species. Accurate spatial assessments of canopy height are essential for improving estimates of aboveground biomass, carbon sequestration, and associated forest ecosystem services in this region. In this study, we estimated canopy heights in the western Himalayas in Pakistan using a U-Net CNN approach, fusing data from the Global Ecosystem Dynamics Investigation Mission (GEDI) with multi-band Sentinel-2 (S2) imagery. We produced a canopy height map at a 10 m resolution for 2020. To ensure accurate measurements across various canopy height groups, we implemented a stratified training approach that optimized the representation of GEDI data throughout the training, validation, and testing phases. We trained multiple models using varying thresholds and assigned different weights to taller trees to improve accuracy between different canopy height groups in the study region. Our best model achieved a Root Mean Square Error (RMSE) of 7.52 m and a Mean Absolute Error (MAE) of 5.71 m in the test set, significantly outperforming existing global canopy height models in this topographically complex region. We further validate our predictions against field inventory plots, achieving a coefficient of determination (R<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>) of 0.49 for plots containing at least 15 trees. The resulting tree canopy height map, designated as the Western Himalaya Canopy Height Map (WHiCH Map), is publicly available.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105030"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105051
Yuting Qiao , Huaan Jin , Tao He , Shunlin Liang , Feng Tian , Wei Zhao , Zhouyang Liu
The fraction of absorbed photosynthetically active radiation (FAPAR) is a critical parameter for measuring the vegetation photosynthetic capacity. The Hi-resolution Global LAnd Surface Satellite (Hi-GLASS) FAPAR product (version 1, V1) from Landsat imagery has been successfully applied to the ecosystem productivity modeling; however, this product algorithm still exhibits some limitations, including the poor adaptability to heterogeneous surfaces and limited physical interpretability, due to the absence of real-world knowledge guidance. To address these issues, we integrated deep transfer learning and radiative transfer models to update the Hi-GLASS FAPAR algorithm and generate the corresponding product (i.e., version 2, V2). A long short-term memory (LSTM) model was pre-trained on Soil-Leaf-Canopy (SLC) simulations and then optimized using physical knowledge-guided transfer learning, which was used to generate the new FAPAR product from Landsat image series. Validation results demonstrated that the Hi-GLASS FAPAR V2 (R2 = 0. 95, RMSE = 0.08) significantly outperformed V1 (R2 = 0.94, RMSE = 0.11), with notable improvements in various vegetation categories and sensors. The greatest improvement of FAPAR was found over multiple forest types, where different forest categories showed substantial gains, with R2 increasing by 2 % − 11 % and RMSE decreasing by 15 % − 55 %, confirming the improved adaptability of our proposed method to heterogeneous canopies. Moreover, the Hi-GLASS V2 product preserved better spatial details than MODIS、GLASS、GEOV2 products, and its temporal dynamics were more closely aligned with field measurements than the V1 product. These advancements highlight the potential of Hi-GLASS FAPAR V2 as valuable data for supporting terrestrial ecosystem studies.
{"title":"High spatial resolution GLASS FAPAR (version 2) product from Landsat imagery: Algorithm development using a knowledge transfer strategy","authors":"Yuting Qiao , Huaan Jin , Tao He , Shunlin Liang , Feng Tian , Wei Zhao , Zhouyang Liu","doi":"10.1016/j.jag.2025.105051","DOIUrl":"10.1016/j.jag.2025.105051","url":null,"abstract":"<div><div>The fraction of absorbed photosynthetically active radiation (FAPAR) is a critical parameter for measuring the vegetation photosynthetic capacity. The Hi-resolution Global LAnd Surface Satellite (Hi-GLASS) FAPAR product (version 1, V1) from Landsat imagery has been successfully applied to the ecosystem productivity modeling; however, this product algorithm still exhibits some limitations, including the poor adaptability to heterogeneous surfaces and limited physical interpretability, due to the absence of real-world knowledge guidance. To address these issues, we integrated deep transfer learning and radiative transfer models to update the Hi-GLASS FAPAR algorithm and generate the corresponding product (i.e., version 2, V2). A long short-term memory (LSTM) model was pre-trained on Soil-Leaf-Canopy (SLC) simulations and then optimized using physical knowledge-guided transfer learning, which was used to generate the new FAPAR product from Landsat image series. Validation results demonstrated that the Hi-GLASS FAPAR V2 (R<sup>2</sup> = 0. 95, RMSE = 0.08) significantly outperformed V1 (R<sup>2</sup> = 0.94, RMSE = 0.11), with notable improvements in various vegetation categories and sensors. The greatest improvement of FAPAR was found over multiple forest types, where different forest categories showed substantial gains, with R<sup>2</sup> increasing by 2 % − 11 % and RMSE decreasing by 15 % − 55 %, confirming the improved adaptability of our proposed method to heterogeneous canopies. Moreover, the Hi-GLASS V2 product preserved better spatial details than MODIS、GLASS、GEOV2 products, and its temporal dynamics were more closely aligned with field measurements than the V1 product. These advancements highlight the potential of Hi-GLASS FAPAR V2 as valuable data for supporting terrestrial ecosystem studies.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105051"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105054
Tianyi Song , Jie Yang , Weidong Sun , Lei Shi , Changcheng Wang , Pingxiang Li , Haiqiang Fu , Lingli Zhao , Peng Shen , Pingping Huang
The complementary measurements of model-based multibaseline (polarimetric) synthetic aperture radar interferometry ((Pol)InSAR) and data-driven SAR tomography (TomoSAR) have become the development trend of forest height mapping missions. Their common core is the characterization of forest vertical structure, which promotes the introduction of TomoSAR reconstructed vertical structure function into (Pol)InSAR forest height inversion model. However, to provide knowledge of vertical structure, TomoSAR measurements have to cover the entire forested area. The high data acquisition cost and multibaseline observation errors hinder its application in large-scale wall-to-wall forest height mapping. Therefore, based on machine learning, this study proposes a small-scale tomography-aided multibaseline (Pol)InSAR (STAMI) framework to derive vertical structure knowledge at low data burden and estimate forest height with high accuracy. The synergy inversion is reformulated as the cross-scale clustering and classification task of the vertical structure knowledge. We conduct TomoSAR only in a small-scale forested area, and establish the mapping relationship between interferometric features and vertical structure with spectral clustering and Support Vector Machine (SVM). In large-scale mapping area, we obtain vertical structure information with only three-baseline (Pol)InSAR, which is used to construct different forest height inversion models. Finally, a reweighted method is applied to resist observation errors to different vertical structures for improving accuracy of three-baseline inversion. Airborne L- and P-band single and fully polarimetric datasets covering boreal and tropical forests are used to demonstrate the superiority of the proposed framework. This research is valuable for data acquisition planning and algorithm application of multibaseline (Pol)InSAR missions aimed at global forest mapping.
{"title":"STAMI: A machine learning-based small-scale tomography-aided multibaseline (Pol)InSAR forest height inversion framework","authors":"Tianyi Song , Jie Yang , Weidong Sun , Lei Shi , Changcheng Wang , Pingxiang Li , Haiqiang Fu , Lingli Zhao , Peng Shen , Pingping Huang","doi":"10.1016/j.jag.2025.105054","DOIUrl":"10.1016/j.jag.2025.105054","url":null,"abstract":"<div><div>The complementary measurements of model-based multibaseline (polarimetric) synthetic aperture radar interferometry ((Pol)InSAR) and data-driven SAR tomography (TomoSAR) have become the development trend of forest height mapping missions. Their common core is the characterization of forest vertical structure, which promotes the introduction of TomoSAR reconstructed vertical structure function into (Pol)InSAR forest height inversion model. However, to provide knowledge of vertical structure, TomoSAR measurements have to cover the entire forested area. The high data acquisition cost and multibaseline observation errors hinder its application in large-scale wall-to-wall forest height mapping. Therefore, based on machine learning, this study proposes a small-scale tomography-aided multibaseline (Pol)InSAR (STAMI) framework to derive vertical structure knowledge at low data burden and estimate forest height with high accuracy. The synergy inversion is reformulated as the cross-scale clustering and classification task of the vertical structure knowledge. We conduct TomoSAR only in a small-scale forested area, and establish the mapping relationship between interferometric features and vertical structure with spectral clustering and Support Vector Machine (SVM). In large-scale mapping area, we obtain vertical structure information with only three-baseline (Pol)InSAR, which is used to construct different forest height inversion models. Finally, a reweighted method is applied to resist observation errors to different vertical structures for improving accuracy of three-baseline inversion. Airborne L- and P-band single and fully polarimetric datasets covering boreal and tropical forests are used to demonstrate the superiority of the proposed framework. This research is valuable for data acquisition planning and algorithm application of multibaseline (Pol)InSAR missions aimed at global forest mapping.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105054"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105073
Zihao Tang , Songshan Yue , Fangzhuo Mu , Yucheng Shu , Zhuo Sun , Yongning Wen
Map design is fundamental to geographic information communication and applications, yet it remains an expertise-intensive task involving complex operational procedures that limit accessibility for diverse users despite the proliferation of digital platforms. This study introduces MapMate, a large language model (LLM)-based framework that enables map design through natural language interaction. MapMate addresses the gap between modification goals expressed in natural language and technical map design configurations by integrating a hierarchical map design knowledge base with platform-specific specifications. The framework comprises four core components: a request validator that ensures cartographic parameter validity and operational feasibility, a map design task planner that decomposes goal-oriented requirements into executable operations, a context information retriever that maintains project coherence, and a map design tool router that orchestrates map design functions. To overcome LLM memory limitations in multi-round interactions, MapMate implements a persistence strategy that maintains records of operational history and map-wide design states. Three case studies validate the framework’s effectiveness across single-layer refinement, cross-layer design refinement, and context-aware map design. Results demonstrate that MapMate successfully bridges natural language interaction and map design, providing a human-AI collaborative environment that reduces technical barriers while maintaining cartographic integrity. This framework represents a promising advancement toward the development of intelligent, accessible map design systems for integration with AI-enhanced GIS applications.
{"title":"MapMate: A framework bridging natural language interaction and map design through large language models","authors":"Zihao Tang , Songshan Yue , Fangzhuo Mu , Yucheng Shu , Zhuo Sun , Yongning Wen","doi":"10.1016/j.jag.2025.105073","DOIUrl":"10.1016/j.jag.2025.105073","url":null,"abstract":"<div><div>Map design is fundamental to geographic information communication and applications, yet it remains an expertise-intensive task involving complex operational procedures that limit accessibility for diverse users despite the proliferation of digital platforms. This study introduces MapMate, a large language model (LLM)-based framework that enables map design through natural language interaction. MapMate addresses the gap between modification goals expressed in natural language and technical map design configurations by integrating a hierarchical map design knowledge base with platform-specific specifications. The framework comprises four core components: a request validator that ensures cartographic parameter validity and operational feasibility, a map design task planner that decomposes goal-oriented requirements into executable operations, a context information retriever that maintains project coherence, and a map design tool router that orchestrates map design functions. To overcome LLM memory limitations in multi-round interactions, MapMate implements a persistence strategy that maintains records of operational history and map-wide design states. Three case studies validate the framework’s effectiveness across single-layer refinement, cross-layer design refinement, and context-aware map design. Results demonstrate that MapMate successfully bridges natural language interaction and map design, providing a human-AI collaborative environment that reduces technical barriers while maintaining cartographic integrity. This framework represents a promising advancement toward the development of intelligent, accessible map design systems for integration with AI-enhanced GIS applications.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105073"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105034
Zongrong Li , Yunlei Su , Filip Biljecki , Wufan Zhao
Buildings play a crucial role in shaping urban environments, influencing their physical, functional, and aesthetic characteristics. However, urban analytics is frequently limited by datasets lacking essential semantic details as well as fragmentation across diverse and incompatible data sources. To address these challenges, we conducted a comprehensive meta-analysis of 6,285 publications (2019–2024). From this review, we identified 11 key visually discernible building characteristics grouped into three branches: satellite house, satellite neighborhood, and street-view. Based on this structured characteristic system, we introduce BuildingMultiView, an innovative framework leveraging fine-tuned Large Language Models (LLMs) to systematically extract semantically detailed building characteristics from integrated satellite and street-view imagery. Using structured image–prompt–label triplets, the model efficiently annotates characteristics at multiple spatial scales. These characteristics include swimming pools, roof types, building density, wall–window ratio, and property types. Together, they provide a comprehensive and multi-perspective building database. Experiments conducted across five cities in the USA with diverse architecture and urban form, San Francisco, San Diego, Salt Lake City, Austin, and New York City, demonstrate significant performance improvements, with an F1 score of 79.77% compared to the untuned base version of ChatGPT’s 45.66%. These results reveal diverse urban building patterns and correlations between architectural and environmental characteristics, showcasing the framework’s capability to analyze both macro-scale and micro-scale urban building data. By integrating multi-perspective data sources with cutting-edge LLMs, BuildingMultiView enhances building data extraction, offering a scalable tool for urban planners to address sustainability, infrastructure, and human-centered design, enabling smarter, resilient cities.
{"title":"BuildingMultiView:powering multi-scale building characterization with large language models and Multi-perspective imagery","authors":"Zongrong Li , Yunlei Su , Filip Biljecki , Wufan Zhao","doi":"10.1016/j.jag.2025.105034","DOIUrl":"10.1016/j.jag.2025.105034","url":null,"abstract":"<div><div>Buildings play a crucial role in shaping urban environments, influencing their physical, functional, and aesthetic characteristics. However, urban analytics is frequently limited by datasets lacking essential semantic details as well as fragmentation across diverse and incompatible data sources. To address these challenges, we conducted a comprehensive <em>meta</em>-analysis of 6,285 publications (2019–2024). From this review, we identified 11 key visually discernible building characteristics grouped into three branches: satellite house, satellite neighborhood, and street-view. Based on this structured characteristic system, we introduce BuildingMultiView, an innovative framework leveraging fine-tuned Large Language Models (LLMs) to systematically extract semantically detailed building characteristics from integrated satellite and street-view imagery. Using structured image–prompt–label triplets, the model efficiently annotates characteristics at multiple spatial scales. These characteristics include swimming pools, roof types, building density, wall–window ratio, and property types. Together, they provide a comprehensive and multi-perspective building database. Experiments conducted across five cities in the USA with diverse architecture and urban form, San Francisco, San Diego, Salt Lake City, Austin, and New York City, demonstrate significant performance improvements, with an F1 score of 79.77% compared to the untuned base version of ChatGPT’s 45.66%. These results reveal diverse urban building patterns and correlations between architectural and environmental characteristics, showcasing the framework’s capability to analyze both macro-scale and micro-scale urban building data. By integrating multi-perspective data sources with cutting-edge LLMs, BuildingMultiView enhances building data extraction, offering a scalable tool for urban planners to address sustainability, infrastructure, and human-centered design, enabling smarter, resilient cities.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105034"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Groundwater-dependent ecosystems (GDEs) provide crucial ecological and hydrological stability but are increasingly threatened by groundwater-dependent invasive plants (GDIPs), particularly in regions with limited water resources. Although GDEs have been widely studied, long-term quantitative assessments of how invasive plants alter these ecosystems remain limited. Hence, this study evaluated the impacts of invasive plants within the GDEs of the Nuwejaars Catchment, South Africa, by monitoring their spatial and temporal dynamics and quantifying the extent to which they displace native plants. Landsat-8 imagery, a Random Forest classifier, and Explainable Artificial Intelligence (XAI) techniques were integrated to map and quantify the annual distribution of GDIPs over a 12-year period. XAI interpretability techniques including SHapley Additive exPlanations (SHAP), partial dependence plots (PDPs), and recursive feature elimination (RFECV) were applied to identify key environmental conditions influencing GDIP occurrence. Spatial-temporal analysis revealed that GDIPs expanded from 40.9 % (1060 ha) in 2013 to 63.9 % (1660 ha) in 2024, displacing large areas of native fynbos vegetation. Inter-annual change analysis showed accelerated GDIP growth following the extreme 2015–2018 drought, which reduced groundwater availability for native species with shallow roots. Elevation, slope, and moisture vegetation indices emerged as the most influential predictors for classification, with PDPs revealing that GDIPs favoured lower elevations and steep slopes. Classification accuracy improved over time, with F1-Scores and overall accuracies ranging between 68.4 % to 82.5 % from 2013 to 2024. Overall, these findings highlight the persistent spread of GDIPs and their potential to transform GDEs in semi-arid areas. This study demonstrates the value of integrating remote sensing and interpretable machine learning to support ecological monitoring and targeted invasive species management.
{"title":"Cloud-based big data analytics for monitoring invasive plants in groundwater-dependent ecosystems of Nuwejaars catchment, South Africa","authors":"Mmasechaba L. Moropane , Cletah Shoko , Timothy Dube , Dominic Mazvimavi","doi":"10.1016/j.jag.2025.105053","DOIUrl":"10.1016/j.jag.2025.105053","url":null,"abstract":"<div><div>Groundwater-dependent ecosystems (GDEs) provide crucial ecological and hydrological stability but are increasingly threatened by groundwater-dependent invasive plants (GDIPs), particularly in regions with limited water resources. Although GDEs have been widely studied, long-term quantitative assessments of how invasive plants alter these ecosystems remain limited. Hence, this study evaluated the impacts of invasive plants within the GDEs of the Nuwejaars Catchment, South Africa, by monitoring their spatial and temporal dynamics and quantifying the extent to which they displace native plants. Landsat-8 imagery, a Random Forest classifier, and Explainable Artificial Intelligence (XAI) techniques were integrated to map and quantify the annual distribution of GDIPs over a 12-year period. XAI interpretability techniques including SHapley Additive exPlanations (SHAP), partial dependence plots (PDPs), and recursive feature elimination (RFECV) were applied to identify key environmental conditions influencing GDIP occurrence. Spatial-temporal analysis revealed that GDIPs expanded from 40.9 % (1060 ha) in 2013 to 63.9 % (1660 ha) in 2024, displacing large areas of native fynbos vegetation. Inter-annual change analysis showed accelerated GDIP growth following the extreme 2015–2018 drought, which reduced groundwater availability for native species with shallow roots. Elevation, slope, and moisture vegetation indices emerged as the most influential predictors for classification, with PDPs revealing that GDIPs favoured lower elevations and steep slopes. Classification accuracy improved over time, with F1-Scores and overall accuracies ranging between 68.4 % to 82.5 % from 2013 to 2024. Overall, these findings highlight the persistent spread of GDIPs and their potential to transform GDEs in semi-arid areas. This study demonstrates the value of integrating remote sensing and interpretable machine learning to support ecological monitoring and targeted invasive species management.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105053"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105049
Zhaohan Huo , Lei Fang , Yukai Chu , Shuo Dang , Jian Yang , Lin Li , Xuan Li , Shilong Ren , Jinyue Chen , Yanbo Peng , Guoqiang Wang , Qiao Wang
Accurate estimation of individual tree biomass in urban landscapes is critical for carbon stock assessment and urban forest management but remains challenging because of the structural complexity and species diversity of urban trees. This study presents an integrated methodological framework that combines deep learning-based tree species identification with LiDAR-derived structural parameter estimation to enable rapid and precise biomass mapping at the individual tree level. Using multiplatform LiDAR data (UAV-borne and handheld mobile laser scanning), we developed a lightweight sample generation method derived from side-view tree projections (SVP) to efficiently construct a species-adaptive training library and proposed a novel individual tree identification approach optimized with the YOLOv11 deep learning algorithm. Our framework systematically evaluated the performance of single-source versus fused LiDAR point clouds across three key metrics: species classification accuracy (achieving 87.3 % on independent test data), structural parameter retrieval (R2 = 0.925 for DBH, R2 = 0.844 for height), and biomass estimation fidelity (86.3 % agreement with field measurements). The results demonstrated that compared with single-source alternatives, data fusion reduces parameter estimation errors by 4.8–56.2 %, while the SVP strategy enables computationally efficient species-specific allometric model matching. This work advances urban forest monitoring by providing a scalable solution that balances scientific rigor with operational practicality, addressing critical gaps in high-resolution biomass mapping for heterogeneous urban ecosystems.
{"title":"Precise urban tree species identification and biomass estimation using UAV–Handheld LiDAR Synergy and YOLOv11 deep learning","authors":"Zhaohan Huo , Lei Fang , Yukai Chu , Shuo Dang , Jian Yang , Lin Li , Xuan Li , Shilong Ren , Jinyue Chen , Yanbo Peng , Guoqiang Wang , Qiao Wang","doi":"10.1016/j.jag.2025.105049","DOIUrl":"10.1016/j.jag.2025.105049","url":null,"abstract":"<div><div>Accurate estimation of individual tree biomass in urban landscapes is critical for carbon stock assessment and urban forest management but remains challenging because of the structural complexity and species diversity of urban trees. This study presents an integrated methodological framework that combines deep learning-based tree species identification with LiDAR-derived structural parameter estimation to enable rapid and precise biomass mapping at the individual tree level. Using multiplatform LiDAR data (UAV-borne and handheld mobile laser scanning), we developed a lightweight sample generation method derived from side-view tree projections (SVP) to efficiently construct a species-adaptive training library and proposed a novel individual tree identification approach optimized with the YOLOv11 deep learning algorithm. Our framework systematically evaluated the performance of single-source versus fused LiDAR point clouds across three key metrics: species classification accuracy (achieving 87.3 % on independent test data), structural parameter retrieval (R<sup>2</sup> = 0.925 for DBH, R<sup>2</sup> = 0.844 for height), and biomass estimation fidelity (86.3 % agreement with field measurements). The results demonstrated that compared with single-source alternatives, data fusion reduces parameter estimation errors by 4.8–56.2 %, while the SVP strategy enables computationally efficient species-specific allometric model matching. This work advances urban forest monitoring by providing a scalable solution that balances scientific rigor with operational practicality, addressing critical gaps in high-resolution biomass mapping for heterogeneous urban ecosystems.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105049"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105050
Shoujia Ren , Yaozhong Pan , Chuanwu Zhao , Yuan Gao , Gelilan Ma
Efficient detection of anomalous artificial surfaces is vital after disasters to support rapid emergency response. This study proposes a novel, training-free texture index method to accurately identify damaged artificial surfaces using post-disaster imagery. The method was tested across diverse disaster sites, including earthquake-affected areas in Turkey (Sites A–C), and tsunami- and tornado-damaged regions in Palu and Joplin (Sites D–I), covering a range of surface types and building structures. Sites A–C were chosen to develop and assess the efficacy of the proposed texture index method. Primarily, the three-dimensional texture features (3DTF) comprised of Contrast, Gabor wavelets, and secondary texture extraction (Con_Gabor), were amalgamated with a K-means classifier to delineate post-disaster artificial surface areas without prior knowledge. Given the discernible texture discrepancies between normal and anomalous artificial surfaces post-disaster, Homogeneity and Entropy texture features derived from Worldview-3 images at each site were leveraged to construct the artificial surface anomaly index (ASAI) for automatically extracting anomalous artificial surfaces. The findings demonstrated high overall accuracies of detecting anomaly artificial surfaces, ranging from 90.07 % to 91.76 % in Sites A–C. Notably, the ASAI outperformed Artificial Neural Network (ANN), Random Forest (RF), and the U-Net model. The overall accuracy (OA) of the ASAI method is 10 %–20 % higher than that of the U-Net model, showing superior automatic performance without necessitating training samples. Furthermore, the effectiveness of ASAI was validated in the Palu and Joplin sites, affirming its utility across diverse disaster scenarios. The damages of steel-tiled houses, middle-level houses and roads were effectively identified as anomaly artificial surfaces. The overall accuracies of the ASAI for identifying anomaly artificial surfaces were 89.55 %–92.5 %. These findings indicate the identification anomaly artificial surface using the ASAI was robust in different types of anomaly artificial surface caused by different disaster. The method of using ASAI to automatically identify anomaly artificial surfaces in post-disaster and single-temporal images has the potential for wide applicability.
{"title":"ASAI: A general and training-free artificial surfaces anomaly index using post-disaster single-temporal and high-resolution imagery","authors":"Shoujia Ren , Yaozhong Pan , Chuanwu Zhao , Yuan Gao , Gelilan Ma","doi":"10.1016/j.jag.2025.105050","DOIUrl":"10.1016/j.jag.2025.105050","url":null,"abstract":"<div><div>Efficient detection of anomalous artificial surfaces is vital after disasters to support rapid emergency response. This study proposes a novel, training-free texture index method to accurately identify damaged artificial surfaces using post-disaster imagery. The method was tested across diverse disaster sites, including earthquake-affected areas in Turkey (Sites A–C), and tsunami- and tornado-damaged regions in Palu and Joplin (Sites D–I), covering a range of surface types and building structures. Sites A–C were chosen to develop and assess the efficacy of the proposed texture index method. Primarily, the three-dimensional texture features (3DTF) comprised of Contrast, Gabor wavelets, and secondary texture extraction (Con_Gabor), were amalgamated with a K-means classifier to delineate post-disaster artificial surface areas without prior knowledge. Given the discernible texture discrepancies between normal and anomalous artificial surfaces post-disaster, Homogeneity and Entropy texture features derived from Worldview-3 images at each site were leveraged to construct the artificial surface anomaly index (ASAI) for automatically extracting anomalous artificial surfaces. The findings demonstrated high overall accuracies of detecting anomaly artificial surfaces, ranging from 90.07 % to 91.76 % in Sites A–C. Notably, the ASAI outperformed Artificial Neural Network (ANN), Random Forest (RF), and the U-Net model. The overall accuracy (OA) of the ASAI method is 10 %–20 % higher than that of the U-Net model, showing superior automatic performance without necessitating training samples. Furthermore, the effectiveness of ASAI was validated in the Palu and Joplin sites, affirming its utility across diverse disaster scenarios. The damages of steel-tiled houses, middle-level houses and roads were effectively identified as anomaly artificial surfaces. The overall accuracies of the ASAI for identifying anomaly artificial surfaces were 89.55 %–92.5 %. These findings indicate the identification anomaly artificial surface using the ASAI was robust in different types of anomaly artificial surface caused by different disaster. The method of using ASAI to automatically identify anomaly artificial surfaces in post-disaster and single-temporal images has the potential for wide applicability.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105050"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-06DOI: 10.1016/j.jag.2025.105063
Lei Xu , Zhongliang Wang , Yongxi Wang , Ting Xiong , Zhenni Ye
Gravesite occupies a nonnegligible fraction of land resources with growing population in China. Apart from public cemeteries, the clandestine gravesites built by local residents distributed over various land surfaces are yet not to be understood. Here, we use high-resolution satellite images and deep learning methods to detect prevailing informal gravesites in highly vegetated land surfaces of southeastern China. The deep learning gravesite detection model is trained, validated and tested using 20,349 manually labeled samples and achieves an average precision (AP) of 0.905 during the testing stage (precision = 0.830, recall = 0.840, F1 score = 0.835). Using 31 million satellite image tiles, we detect nearly one million (996,074) clandestine gravesites over the land surfaces of Zhejiang, Fujian and Guangdong provinces, especially in forests and croplands. Further spatial attribution analysis suggests that the detected mass informal gravesites are closely related to gross domestic product (GDP) per capita, elevation, vegetation cover, climatic factors and the distances to rivers and coastlines. These findings and conclusions may provide meaningful references for gravesite occupied land use monitoring and management at regional to national scales.
{"title":"Million clandestine gravesites over southeastern China’s land surfaces revealed by satellite images","authors":"Lei Xu , Zhongliang Wang , Yongxi Wang , Ting Xiong , Zhenni Ye","doi":"10.1016/j.jag.2025.105063","DOIUrl":"10.1016/j.jag.2025.105063","url":null,"abstract":"<div><div>Gravesite occupies a nonnegligible fraction of land resources with growing population in China. Apart from public cemeteries, the clandestine gravesites built by local residents distributed over various land surfaces are yet not to be understood. Here, we use high-resolution satellite images and deep learning methods to detect prevailing informal gravesites in highly vegetated land surfaces of southeastern China. The deep learning gravesite detection model is trained, validated and tested using 20,349 manually labeled samples and achieves an average precision (AP) of 0.905 during the testing stage (precision = 0.830, recall = 0.840, F1 score = 0.835). Using 31 million satellite image tiles, we detect nearly one million (996,074) clandestine gravesites over the land surfaces of Zhejiang, Fujian and Guangdong provinces, especially in forests and croplands. Further spatial attribution analysis suggests that the detected mass informal gravesites are closely related to gross domestic product (GDP) per capita, elevation, vegetation cover, climatic factors and the distances to rivers and coastlines. These findings and conclusions may provide meaningful references for gravesite occupied land use monitoring and management at regional to national scales.</div></div>","PeriodicalId":73423,"journal":{"name":"International journal of applied earth observation and geoinformation : ITC journal","volume":"146 ","pages":"Article 105063"},"PeriodicalIF":8.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}