Distributed, physics-based hydrologic models require spatially explicit specification of parameters related to climate, geology, land-cover, soil, and topography. Extracting these parameters from ...national geodatabases requires intensive data processing. Furthermore, mapping these parameters to model mesh elements necessitates development of data access tools that can handle both spatial and temporal datasets. This paper presents an open-source, platform independent, tightly coupled GIS and distributed hydrologic modeling framework, PIHMgis (www.pihm.psu.edu), to improve model-data integration. Tight coupling is achieved through the development of an integrated user interface with an underlying shared geodata model, which improves data flow between the PIHMgis data processing components. The capability and effectiveness of the PIHMgis framework in providing functionalities for watershed delineation, domain decomposition, parameter assignment, simulation, visualization and analyses, is demonstrated through prototyping of a model simulation. The framework and the approach are applicable for watersheds of varied sizes, and offer a template for future GIS-Model integration efforts.
•A coupled GIS and distributed hydrologic modeling framework, PIHMgis was developed.•PIHMgis uses national geospatial dataset to setup, execute, and analyze simulations.•Procedural framework improves model-data integration using shared geodata model.
Spatial interactions underlying consecutive sequential snapshots of spatial distributions, such as the migration flows underlying temporal population snapshots, can reflect the details of spatial ...evolution processes. In the era of big data, we have access to individual-level data, but the acquisition of high-quality spatial interaction data remains a challenging problem. Most research has been focused on distributions of movable objects or the modelling of spatial interaction patterns, with few attempts to identify hidden spatial interaction patterns from temporal transitions of spatial distributions. In this article, we introduced an approach to infer spatial interaction patterns from sequential snapshots of spatial population distributions by incorporating linear programming and the spatial constraints of human movement. Experiments using synthetic data were conducted using four simple scenarios to explore the characteristics of our method. The proposed method was used to extract interurban flows of migrants during the Chinese Spring Festival in 2016. Our research demonstrated the feasibility of using discrete multi-temporal snapshots of population distributions in space to infer spatial interaction patterns and offered a general analytical framework from snapshot data to spatial interaction patterns.
Social media, particularly Twitter, is increasingly used to improve resilience during extreme weather events/emergency management situations, including floods: by communicating potential risks and ...their impacts, and informing agencies and responders. In this paper, we developed a prototype national-scale Twitter data mining pipeline for improved stakeholder situational awareness during flooding events across Great Britain, by retrieving relevant social geodata, grounded in environmental data sources (flood warnings and river levels). With potential users we identified and addressed three research questions to develop this application, whose components constitute a modular architecture for real-time dashboards. First, polling national flood warning and river level Web data sources to obtain at-risk locations. Secondly, real-time retrieval of geotagged tweets, proximate to at-risk areas. Thirdly, filtering flood-relevant tweets with natural language processing and machine learning libraries, using word embeddings of tweets. We demonstrated the national-scale social geodata pipeline using over 420,000 georeferenced tweets obtained between 20 and 29th June 2016.
•Prototype real-time social geodata pipeline for flood events and demonstration dataset.•National-scale flood warnings/river levels set ‘at-risk areas’ in Twitter API queries.•Monitoring multiple locations (without keywords) retrieved current, geotagged tweets.•Novel application of word embeddings in flooding context identified relevant tweets.•Pipeline extracts tweets to visualise using open-source libraries (SciKit Learn/Gensim).
Aim: Comparative phylogeography across a large number of species allows investigating community-level processes at regional and continental scales. An effective approach to such studies would involve ...automatic retrieval of georeferenced sequence data from nucleotide databases (a first step towards an 'automated phylogeography'). It remains unclear if, despite repeated calls, georeferencing of nucleotide databases has increased in frequency, and if accumulated data allow for broad applications based on automated retrieval of sequence data and associated geographical information. Here, we investigated geographical information available in NCBI GenBank accessions for tetrapods, exploring temporal and geographical patterns in georeferencing, and quantifying data available for automated phylogeography. Location: Global. Methods: We developed Python and R scripts to (1) download metadata from GenBank (1,125,514 accessions, > 20,000 species); (2) geocode accessions from associated metadata; (3) map originally georeferenced and geocoded accessions and plot their frequency against time; (4) assess the size of intraspecific sets of homologous sequences and compare their geographical extent with species ranges, thus evaluating their potential for phylogeographical analyses. Results: Only 6.2% of surveyed tetrapod GenBank submissions reported geographical coordinates, without increase in recent years. Our geocoding raised georeferenced accessions to 15.1%. The geographical distribution of georeferenced accessions is patchy, and especially sparse in economically underdeveloped areas. Automatically retrievable informative data sets covering most of the range are available for very few species of wide-ranging tetrapods. Main conclusions: Although geocoding offers a partial solution to the scarcity of direct georeferencing, the amount of data potentially useful for automated phylogeography is still limited. Strong underrepresentation of hard-to-access areas suggests that sampling logistics represent a main hindrance to global data availability. We propose that, besides enhancing georeferencing of genetic data, future research agendas should focus on collaborative efforts to sample genetic diversity in biodiversity-rich tropical areas.
This open access book provides an overview of the progress in landslide research and technology and is part of a book series of the International Consortium on Landslides (ICL). The book provides a ...common platform for the publication of recent progress in landslide research and technology for practical applications and the benefit for the society contributing to the Kyoto Landslide Commitment 2020, which is expected to continue up to 2030 and even beyond to globally promote the understanding and reduction of landslide disaster risk, as well as to address the 2030 Agenda Sustainable Development Goals.
This open access book includes methods for retrieval, semantic representation, and analysis of Volunteered Geographic Information (VGI), geovisualization and user interactions related to VGI, and ...discusses selected topics in active participation, social context, and privacy awareness. It presents the results of the DFG-funded priority program "VGI: Interpretation, Visualization, and Social Computing" (2016-2023). The book includes three parts representing the principal research pillars within the program. Part I "Representation and Analysis of VGI" discusses recent approaches to enhance the representation and analysis of VGI. It includes semantic representation of VGI data in knowledge graphs; machine-learning approaches to VGI mining, completion, and enrichment as well as to the improvement of data quality and fitness for purpose. Part II "Geovisualization and User Interactions related to VGI" book explores geovisualizations and user interactions supporting the analysis and presentation of VGI data. When designing these visualizations and user interactions, the specific properties of VGI data, the knowledge and abilities of different target users, and technical viability of solutions need to be considered. Part III "Active Participation, Social Context and Privacy Awareness" of the book addresses the human impact associated with VGI. It includes chapters on the use of wearable sensors worn by volunteers to record their exposure to environmental stressors on their daily journeys, on the collective behavior of people using location-based social media and movement data from football matches, and on the motivation of volunteers who provide important support in information gathering, filtering and analysis of social media in disaster situations. The book is of interest to researchers and advanced professionals in geoinformation, cartography, visual analytics, data science and machine learning.
This open access volume contains the proceedings of the X Hotine-Marussi Symposium on Mathematical Geodesy which was held from 13 to 17 June 2022 at the Politecnico di Milano, Milan, Italy. Since ...2006 the series of the Hotine-Marussi Symposia has been under the responsibility of the Inter-Commission Committee on Theory (ICCT) within the International Association of Geodesy (IAG). The ICCT organized the last five Hotine-Marussi Symposia held in Wuhan (2006), Rome (2009, 2013 and 2018), and Milan (2022). The overall goal of the ICCT and Hotine-Marussi Symposia has always been to advance geodetic theory which is indeed documented by the 22 research articles published in these proceedings. The jubilee X Hotine-Marussi Symposium was organized in 10 topical sessions covering all parts of geodetic theory including reference frames, gravity field modelling, adjustment theory, height systems, time series analysis, or advanced numerical methods. In total, 60 participants attended the Symposium who delivered 62 oral and 18 poster presentations. During a special session, five invited speakers discussed two basic concepts of physical geodesy – geoid and quasigeoid.
PDF
