@article{white_petrasova_petras_tateosian_vukomanovic_mitasova_meentemeyer_2023, title={An open-source platform for geospatial participatory modeling in the cloud}, volume={167}, ISSN={["1873-6726"]}, url={http://dx.doi.org/10.1016/j.envsoft.2023.105767}, DOI={10.1016/j.envsoft.2023.105767}, abstractNote={Participatory modeling facilitates the co-production of knowledge and action by engaging stakeholders in research. However, the spatial dimensions of socio-environmental systems and decision-making are challenging to incorporate in participatory models, as developing interactive geospatial models requires specialized knowledge. Yet, many of society’s most pressing and complex socio-environmental problems require participatory modeling that is geospatial. Existing interactive online applications have broadened the audiences who can engage with geospatial models, but often do not provide a robust framework for interactive model development. Here, we develop an open-source platform, OpenPlains, to address barriers to participation in geospatial modeling by enabling researchers to develop interactive models that remove barriers to data aggregation and user engagement. OpenPlains consists of six new open-source libraries: OpenPlains, django-actina, grass-js-client, react-openplains, react-ol, and openplains-cli. We demonstrate OpenPlains through two web applications that work anywhere in the contiguous United States: a spatial–temporal watershed analysis application and an urban growth forecasting application.}, journal={ENVIRONMENTAL MODELLING & SOFTWARE}, publisher={Elsevier BV}, author={White, Corey T. and Petrasova, Anna and Petras, Vaclav and Tateosian, Laura G. and Vukomanovic, Jelena and Mitasova, Helena and Meentemeyer, Ross K.}, year={2023}, month={Sep} }
 @article{haedrich_petras_petrasova_blumentrath_mitasova_2023, title={Integrating GRASS GIS and Jupyter Notebooks to facilitate advanced geospatial modeling education}, volume={27}, url={http://dx.doi.org/10.1111/tgis.13031}, DOI={10.1111/tgis.13031}, abstractNote={Open education materials are critical for the advancement of open science and the development of open‐source software. These accessible and transparent materials provide an important pathway for sharing both standard geospatial analysis workflows and advanced research methods. Computational notebooks allow users to share live code with in‐line visualizations and narrative text, making them a powerful interactive teaching tool for geospatial analytics. Specifically, Jupyter Notebooks are quickly becoming a standard format in open education. In this article, we introduce a new GRASS GIS package, grass.jupyter, that enhances the existing GRASS Python API to allow Jupyter Notebook users to easily manage and visualize GRASS data including spatiotemporal datasets. While there are many Python‐based geospatial libraries available for use in Jupyter Notebooks, GRASS GIS has extensive geospatial functionality including support for multi‐temporal analysis and dynamic simulations, making it a powerful teaching tool for advanced geospatial analytics. We discuss the development of grass.jupyter and demonstrate how the package facilitates teaching open‐source geospatial modeling with a collection of Jupyter Notebooks designed for a graduate‐level geospatial modeling course. The open education notebooks feature spatiotemporal data visualizations, hydrologic modeling, and spread simulations such as the spread of invasive species and urban growth.}, number={3}, journal={Transactions in GIS}, publisher={Wiley}, author={Haedrich, Caitlin and Petras, Vaclav and Petrasova, Anna and Blumentrath, Stefan and Mitasova, Helena}, year={2023}, month={May}, pages={686–702} }
 @article{petras_petrasova_mccarter_mitasova_meentemeyer_2023, title={Point Density Variations in Airborne Lidar Point Clouds}, volume={23}, ISSN={["1424-8220"]}, url={https://www.mdpi.com/1424-8220/23/3/1593}, DOI={10.3390/s23031593}, abstractNote={In spite of increasing point density and accuracy, airborne lidar point clouds often exhibit point density variations. Some of these density variations indicate issues with point clouds, potentially leading to errors in derived products. To highlight these issues, we provide an overview of point density variations and show examples in six airborne lidar point cloud datasets that we used in our topographic and geospatial modeling research. Using the published literature, we identified sources of point density variations and issues indicated or caused by these variations. Lastly, we discuss the reduction in point density variations using decimations, homogenizations, and their applicability.}, number={3}, journal={SENSORS}, author={Petras, Vaclav and Petrasova, Anna and McCarter, James B. and Mitasova, Helena and Meentemeyer, Ross K.}, year={2023}, month={Feb} }
 @article{karlovska_petrasova_petras_landa_2023, title={Redesigning Graphical User Interface of Open-Source Geospatial Software in a Community-Driven Way: A Case Study of GRASS GIS}, volume={12}, ISSN={["2220-9964"]}, url={https://www.mdpi.com/2220-9964/12/9/376}, DOI={10.3390/ijgi12090376}, abstractNote={Learning to use geographic information system (GIS) software effectively may be intimidating due to the extensive range of features it offers. The GRASS GIS software, in particular, presents additional challenges for first-time users in terms of its complex startup procedure and unique terminology associated with its data structure. On the other hand, a substantial part of the GRASS user community including us as developers recognized and embraced the advantages of the current approach. Given the controversial nature of the whole issue, we decided to actively involve regular users by conducting several formal surveys and by performing usability testing. Throughout this process, we discovered that resolving specific software issues through pure user-centered design is not always feasible, particularly in the context of open-source scientific software where the boundary between users and developers is very fuzzy. To address this challenge, we adopted the user-centered methodology tailored to the requirements of open-source scientific software development, which we refer to as community-driven design. This paper describes the community-driven redesigning process on the GRASS GIS case study and sets a foundation for applying community-driven design in other open-source scientific projects by providing insights into effective software development practices driven by the needs and input of the project’s community.}, number={9}, journal={ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION}, author={Karlovska, Linda and Petrasova, Anna and Petras, Vaclav and Landa, Martin}, year={2023}, month={Sep} }
 @article{sanchez_petrasova_skrip_collins_lawrimore_vogler_terando_vukomanovic_mitasova_meentemeyer_2023, title={Spatially interactive modeling of land change identifies location-specific adaptations most likely to lower future flood risk}, volume={13}, ISSN={["2045-2322"]}, url={http://dx.doi.org/10.1038/s41598-023-46195-9}, DOI={10.1038/s41598-023-46195-9}, abstractNote={Abstract Impacts of sea level rise will last for centuries; therefore, flood risk modeling must transition from identifying risky locations to assessing how populations can best cope. We present the first spatially interactive (i.e., what happens at one location affects another) land change model (FUTURES 3.0) that can probabilistically predict urban growth while simulating human migration and other responses to flooding, essentially depicting the geography of impact and response. Accounting for human migration reduced total amounts of projected developed land exposed to flooding by 2050 by 5%–24%, depending on flood hazard zone (50%–0.2% annual probability). We simulated various “what-if” scenarios and found managed retreat to be the only intervention with predicted exposure below baseline conditions. In the business-as-usual scenario, existing and future development must be either protected or abandoned to cope with future flooding. Our open framework can be applied to different regions and advances local to regional-scale efforts to evaluate potential risks and tradeoffs.}, number={1}, journal={SCIENTIFIC REPORTS}, publisher={Springer Science and Business Media LLC}, author={Sanchez, Georgina M. and Petrasova, Anna and Skrip, Megan M. and Collins, Elyssa L. and Lawrimore, Margaret A. and Vogler, John B. and Terando, Adam and Vukomanovic, Jelena and Mitasova, Helena and Meentemeyer, Ross K.}, year={2023}, month={Nov} }
 @article{inglis_vukomanovic_petrasova_meentemeyer_2023, title={Viewscape change highlights shifting drivers of exurban development over time}, volume={238}, ISSN={["1872-6062"]}, url={http://dx.doi.org/10.1016/j.landurbplan.2023.104833}, DOI={10.1016/j.landurbplan.2023.104833}, abstractNote={Exurban development has increased over recent decades, characterized by low-density, amenity-driven housing development, and shaped by the landscape’s visual quality, rural character and perceived quality of life. Viewscapes—the 3-dimensional portions of landscapes with which people form a connection—are one way to quantify visual character and assess how those aesthetic amenities interact with other drivers to shape exurban development. The extent to which a landscape changes over time due to anthropogenic and natural processes—such as new housing development or wildfire—has largely been overlooked in models of development that include viewscape metrics. In this study, we use an event-history analysis approach to model the relationship between known drivers, including viewscape metrics (area, land cover, terrain complexity and visible neighbors), and the timing of exurban development of 1,807 single-family residences in Boulder County, Colorado, USA between 1990 and 2020. Most viewscape metrics’ effects on the timing of new home builds varied by 5-year time interval, underscoring the constraints of temporally static development models. We found that houses were more likely to be located close to major roads, and with views of less complex terrain. Larger views and fewer visible neighbors emerged as predictors of development over the study period. In the early-2000s, developed sites favored sunnier aspects, and views that avoided burn scars and developed areas. After 2010, new homes sites avoided views of developed areas and favored forested views. Insight into changing relationships between viewscapes and exurban housing development can highlight the effects of landscape change on visual quality and the trade-offs inherent in housing location decisions. Exploring how viewscape drivers and their effects on development change over time offers land managers and policymakers a more detailed picture of the amenity factors shaping exurban development.}, journal={LANDSCAPE AND URBAN PLANNING}, publisher={Elsevier BV}, author={Inglis, Nicole C. and Vukomanovic, Jelena and Petrasova, Anna and Meentemeyer, Ross K.}, year={2023}, month={Oct} }
 @article{petrasova_2022, title={FUTURES v3.0.0 software for urban growth modeling}, url={https://zenodo.org/record/6607097}, DOI={10.5281/ZENODO.6607097}, publisher={Zenodo}, author={Petrasova, Anna}, year={2022}, month={Jun} }
 @article{landa_neteler_metz_petrasova_delucchi_zambelli_barton_zigo_chemin_kudrnovsky_et al._2022, title={GRASS GIS 8.2.0}, url={https://zenodo.org/record/6612307}, DOI={10.5281/ZENODO.6612307}, publisher={Zenodo}, author={Landa, Martin and Neteler, Markus and Metz, Markus and Petrasova, Anna and Delucchi, Luca and Zambelli, Pietro and Barton, Michael and Zigo, Tomas and Chemin, Yann and Kudrnovsky, Helmut and et al.}, year={2022}, month={Jun} }
 @article{white_reckling_petrasova_meentemeyer_mitasova_2022, title={Rapid-DEM: Rapid Topographic Updates through Satellite Change Detection and UAS Data Fusion}, volume={14}, ISSN={["2072-4292"]}, url={https://www.mdpi.com/2072-4292/14/7/1718}, DOI={10.3390/rs14071718}, abstractNote={As rapid urbanization occurs in cities worldwide, the importance of maintaining updated digital elevation models (DEM) will continue to increase. However, due to the cost of generating high-resolution DEM over large spatial extents, the temporal resolution of DEMs is coarse in many regions. Low-cost unmanned aerial vehicles (UAS) and DEM data fusion provide a partial solution to improving the temporal resolution of DEM but do not identify which areas of a DEM require updates. We present Rapid-DEM, a framework that identifies and prioritizes locations with a high likelihood of an urban topographic change to target UAS data acquisition and fusion to provide up-to-date DEM. The framework uses PlanetScope 3 m satellite imagery, Google Earth Engine, and OpenStreetMap for land cover classification. GRASS GIS generates a contextualized priority queue from the land cover data and outputs polygons for UAS flight planning. Low-cost UAS fly the identified areas, and WebODM generates a DEM from the UAS survey data. The UAS data is fused with an existing DEM and uploaded to a public data repository. To demonstrate Rapid-DEM a case study in the Walnut Creek Watershed in Wake County, North Carolina is presented. Two land cover classification models were generated using random forests with an overall accuracy of 89% (kappa 0.86) and 91% (kappa 0.88). The priority queue identified 109 priority locations representing 1.5% area of the watershed. Large forest clearings were the highest priority locations, followed by newly constructed buildings. The highest priority site was a 0.5 km2 forest clearing that was mapped with UAS, generating a 15 cm DEM. The UAS DEM was resampled to 3 m resolution and fused with USGS NED 1/9 arc-second DEM data. Surface water flow was simulated over the original and updated DEM to illustrate the impact of the topographic change on flow patterns and highlight the importance of timely DEM updates.}, number={7}, journal={REMOTE SENSING}, publisher={MDPI AG}, author={White, Corey T. and Reckling, William and Petrasova, Anna and Meentemeyer, Ross K. and Mitasova, Helena}, year={2022}, month={Apr} }
 @article{jones_skrip_seliger_jones_wakie_takeuchi_petras_petrasova_meentemeyer_2022, title={Spotted lanternfly predicted to establish in California by 2033 without preventative management}, volume={5}, ISSN={["2399-3642"]}, url={https://doi.org/10.1038/s42003-022-03447-0}, DOI={10.1038/s42003-022-03447-0}, abstractNote={Models that are both spatially and temporally dynamic are needed to forecast where and when non-native pests and pathogens are likely to spread, to provide advance information for natural resource managers. The potential US range of the invasive spotted lanternfly (SLF, Lycorma delicatula) has been modeled, but until now, when it could reach the West Coast's multi-billion-dollar fruit industry has been unknown. We used process-based modeling to forecast the spread of SLF assuming no treatments to control populations occur. We found that SLF has a low probability of first reaching the grape-producing counties of California by 2027 and a high probability by 2033. Our study demonstrates the importance of spatio-temporal modeling for predicting the spread of invasive species to serve as an early alert for growers and other decision makers to prepare for impending risks of SLF invasion. It also provides a baseline for comparing future control options.}, number={1}, journal={COMMUNICATIONS BIOLOGY}, author={Jones, Chris and Skrip, Megan M. and Seliger, Benjamin J. and Jones, Shannon and Wakie, Tewodros and Takeuchi, Yu and Petras, Vaclav and Petrasova, Anna and Meentemeyer, Ross K.}, year={2022}, month={Jun} }
 @article{petrasova_petras_harmon_2022, title={Tangible Landscape software}, url={https://zenodo.org/record/5160087}, DOI={10.5281/ZENODO.5160087}, publisher={Zenodo}, author={Petrasova, Anna and Petras, Vaclav and Harmon, Brendan}, year={2022}, month={Jun} }
 @article{gaydos_jones_jones_millar_petras_petrasova_mitasova_meentemeyer_2021, title={Evaluating online and tangible interfaces for engaging stakeholders in forecasting and control of biological invasions}, volume={9}, ISSN={["1939-5582"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85115251448&partnerID=MN8TOARS}, DOI={10.1002/eap.2446}, abstractNote={Abstract Ecological forecasts will be best suited to inform intervention strategies if they are accessible to a diversity of decision‐makers. Researchers are developing intuitive forecasting interfaces to guide stakeholders through the development of intervention strategies and visualization of results. Yet, few studies to date have evaluated how user interface design facilitates the coordinated, cross‐boundary management required for controlling biological invasions. We used a participatory approach to develop complementary tangible and online interfaces for collaboratively forecasting biological invasions and devising control strategies. A diverse group of stakeholders evaluated both systems in the real‐world context of controlling sudden oak death, an emerging forest disease killing millions of trees in California and Oregon. Our findings suggest that while both interfaces encouraged adaptive experimentation, tangible interfaces are particularly well suited to support collaborative decision‐making. Reflecting on the strengths of both systems, we suggest workbench‐style interfaces that support simultaneous interactions and dynamic geospatial visualizations.}, number={8}, journal={ECOLOGICAL APPLICATIONS}, publisher={Wiley}, author={Gaydos, Devon A. and Jones, Chris M. and Jones, Shannon K. and Millar, Garrett C. and Petras, Vaclav and Petrasova, Anna and Mitasova, Helena and Meentemeyer, Ross K.}, year={2021}, month={Sep} }
 @article{jones_jones_petrasova_petras_gaydos_skrip_takeuchi_bigsby_meentemeyer_2021, title={Iteratively forecasting biological invasions with PoPS and a little help from our friends}, volume={6}, ISSN={["1540-9309"]}, url={http://dx.doi.org/10.1002/fee.2357}, DOI={10.1002/fee.2357}, abstractNote={Ecological forecasting has vast potential to support environmental decision making with repeated, testable predictions across management‐relevant timescales and locations. Yet resource managers rarely use co‐designed forecasting systems or embed them in decision making. Although prediction of planned management outcomes is particularly important for biological invasions to optimize when and where resources should be allocated, spatial–temporal models of spread typically have not been openly shared, iteratively updated, or interactive to facilitate exploration of management actions. We describe a species‐agnostic, open‐source framework – called the Pest or Pathogen Spread (PoPS) Forecasting Platform – for co‐designing near‐term iterative forecasts of biological invasions. Two case studies are presented to demonstrate that iterative calibration yields higher forecast skill than using only the earliest‐available data to predict future spread. The PoPS framework is a primary example of an ecological forecasting system that has been both scientifically improved and optimized for real‐world decision making through sustained participation and use by management stakeholders.}, number={7}, journal={FRONTIERS IN ECOLOGY AND THE ENVIRONMENT}, publisher={Wiley}, author={Jones, Chris M. and Jones, Shannon and Petrasova, Anna and Petras, Vaclav and Gaydos, Devon and Skrip, Megan M. and Takeuchi, Yu and Bigsby, Kevin and Meentemeyer, Ross K.}, year={2021}, month={Jun} }
 @article{millar_mitas_boode_hoeke_kruijf_petrasova_mitasova_2021, title={Space-time analytics of human physiology for urban planning}, volume={85}, ISBN={1873-7587}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85092914107&partnerID=MN8TOARS}, DOI={10.1016/j.compenvurbsys.2020.101554}, abstractNote={Recent advancements in mobile sensing and wearable technologies create new opportunities to improve our understanding of how people experience their environment. This understanding can inform urban design decisions. Currently, an important urban design issue is the adaptation of infrastructure to increasing cycle and e-bike use. Using data collected from 12 cyclists on a cycle highway between two municipalities in The Netherlands, we coupled location and wearable emotion data at a high spatiotemporal resolution to model and examine relationships between cyclists' emotional arousal (operationalized as skin conductance responses) and visual stimuli from the environment (operationalized as extent of visible land cover type). We specifically took a within-participants multilevel modeling approach to determine relationships between different types of viewable land cover area and emotional arousal, while controlling for speed, direction, distance to roads, and directional change. Surprisingly, our model suggests ride segments with views of larger natural, recreational, agricultural, and forested areas were more emotionally arousing for participants. Conversely, segments with views of larger developed areas were less arousing. The presented methodological framework, spatial-emotional analyses, and findings from multilevel modeling provide new opportunities for spatial, data-driven approaches to portable sensing and urban planning research. Furthermore, our findings have implications for design of infrastructure to optimize cycling experiences.}, journal={COMPUTERS ENVIRONMENT AND URBAN SYSTEMS}, author={Millar, Garrett C. and Mitas, Ondrej and Boode, Wilco and Hoeke, Lisette and Kruijf, Joost and Petrasova, Anna and Mitasova, Helena}, year={2021}, month={Jan} }
 @article{petrasova_gaydos_petras_jones_mitasova_meentemeyer_2020, title={Geospatial simulation steering for adaptive management}, volume={133}, url={http://dx.doi.org/10.1016/j.envsoft.2020.104801}, DOI={10.1016/j.envsoft.2020.104801}, abstractNote={Spatio-temporal simulations are becoming essential tools for decision makers when forecasting future conditions and evaluating effectiveness of alternative decision scenarios. However, lack of interactive steering capabilities limits the value of advanced stochastic simulations for research and practice. To address this gap we identified conceptual challenges associated with steering stochastic, spatio-temporal simulations and developed solutions that better represent the realities of decision-making by allowing both reactive and proactive, spatially-explicit interventions. We present our approach, in a participatory modeling case study engaging stakeholders in developing strategies to contain the spread of a tree disease in Oregon, USA. Using intuitive interfaces, implemented through web-based and tangible platforms, stakeholders explored management options as the simulation progressed. Spatio-temporal steering allowed them to combine currently used management practices into novel adaptive management strategies, which were previously difficult to test and assess, demonstrating the utility of interactive simulations for decision-making.}, journal={Environmental Modelling & Software}, publisher={Elsevier BV}, author={Petrasova, Anna and Gaydos, Devon A. and Petras, Vaclav and Jones, Chris M. and Mitasova, Helena and Meentemeyer, Ross K.}, year={2020}, month={Nov}, pages={104801} }
 @article{tabrizian_petrasova_baran_vukomanovic_mitasova_meentemeyer_2020, title={High Resolution Viewscape Modeling Evaluated Through Immersive Virtual Environments}, volume={9}, url={http://dx.doi.org/10.3390/ijgi9070445}, DOI={10.3390/ijgi9070445}, abstractNote={Visual characteristics of urban environments influence human perception and behavior, including choices for living, recreation and modes of transportation. Although geospatial visualizations hold great potential to better inform urban planning and design, computational methods are lacking to realistically measure and model urban and parkland viewscapes at sufficiently fine-scale resolution. In this study, we develop and evaluate an integrative approach to measuring and modeling fine-scale viewscape characteristics of a mixed-use urban environment, a city park. Our viewscape approach improves the integration of geospatial and perception elicitation techniques by combining high-resolution lidar-based digital surface models, visual obstruction, and photorealistic immersive virtual environments (IVEs). We assessed the realism of our viewscape models by comparing metrics of viewscape composition and configuration to human subject evaluations of IVEs across multiple landscape settings. We found strongly significant correlations between viewscape metrics and participants’ perceptions of viewscape openness and naturalness, and moderately strong correlations with landscape complexity. These results suggest that lidar-enhanced viewscape models can adequately represent visual characteristics of fine-scale urban environments. Findings also indicate the existence of relationships between human perception and landscape pattern. Our approach allows urban planners and designers to model and virtually evaluate high-resolution viewscapes of urban parks and natural landscapes with fine-scale details never before demonstrated.}, number={7}, journal={ISPRS International Journal of Geo-Information}, publisher={MDPI AG}, author={Tabrizian, Payam and Petrasova, Anna and Baran, Perver and Vukomanovic, Jelena and Mitasova, Helena and Meentemeyer, Ross}, year={2020}, month={Jul}, pages={445} }
 @article{gaydos_petrasova_cobb_meentemeyer_2019, title={Forecasting and control of emerging infectious forest disease through participatory modelling}, volume={374}, ISSN={["1471-2970"]}, url={https://doi.org/10.1098/rstb.2018.0283}, DOI={10.1098/rstb.2018.0283}, abstractNote={Epidemiological models are powerful tools for evaluating scenarios and visualizing patterns of disease spread, especially when comparing intervention strategies. However, the technical skill required to synthesize and operate computational models frequently renders them beyond the command of the stakeholders who are most impacted by the results. Participatory modelling (PM) strives to restructure the power relationship between modellers and the stakeholders who rely on model insights by involving these stakeholders directly in model development and application; yet, a systematic literature review indicates little adoption of these techniques in epidemiology, especially plant epidemiology. We investigate the potential for PM to integrate stakeholder and researcher knowledge, using Phytophthora ramorum and the resulting sudden oak death disease as a case study. Recent introduction of a novel strain (European 1 or EU1) in southwestern Oregon has prompted significant concern and presents an opportunity for coordinated management to minimize regional pathogen impacts. Using a PM framework, we worked with local stakeholders to develop an interactive forecasting tool for evaluating landscape-scale control strategies. We find that model co-development has great potential to empower stakeholders in the design, development and application of epidemiological models for disease control. This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’. This theme issue is linked with the earlier issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’.}, number={1776}, journal={PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES}, publisher={The Royal Society}, author={Gaydos, Devon A. and Petrasova, Anna and Cobb, Richard C. and Meentemeyer, Ross K.}, year={2019}, month={Jul} }
 @article{vukomanovic_vogler_petrasova_2019, title={Modeling the connection between viewscapes and home locations in a rapidly exurbanizing region}, volume={78}, ISSN={["1873-7587"]}, DOI={10.1016/j.compenvurbsys.2019.101388}, abstractNote={Low-density exurban development represents a unique form of landscape change motivated by aesthetics and individual choice, whether driven by perceptions of beauty or more broadly as worldviews expressed through outward appearance and actions. However, little is known about how individual preferences for new home sites manifest in landscape patterns of exurbanization. In this study, we examine the extent to which viewscapes - the visible part of a landscape that creates connection between people and their surroundings - drive patterns of development in the Sonoita Plain of Arizona. We mapped the locations of over 2,000 homes built before and after the Great Recession (~2010) and calculated line-of-sight viewscapes of each home with four metrics: viewscape area, privacy (number of visible neighbors), greenness (NDVI), and terrain ruggedness. We found that exurban homes have significantly larger and more private viewscapes compared to suburban homes and what would be expected by chance. After 2010, exurban homes were built at locations with yet larger and more private viewscapes even as settlement density increased. An autologistic model of post-2010 settlement patterns showed that viewscape privacy is positively associated with the probability of exurban development after accounting for road proximity and the area and greenness of viewscapes. Application of the predictive model was made possible through a new open-source algorithm that computes spatially continuous, all-possible vantage points (1.3M). Our algorithm allows planners to visualize wall-to-wall spatial patterns of viewscape drivers across a large region and more comprehensively consider the roles that viewscapes play in landscape change.}, journal={COMPUTERS ENVIRONMENT AND URBAN SYSTEMS}, author={Vukomanovic, Jelena and Vogler, John B. and Petrasova, Anna}, year={2019}, month={Nov} }
 @article{berkel_shashidharan_mordecai_vatsavai_petrasova_petras_mitasova_vogler_meentemeyer_2019, title={Projecting Urbanization and Landscape Change at Large Scale Using the FUTURES Model}, volume={8}, url={https://www.mdpi.com/2073-445X/8/10/144}, DOI={10.3390/land8100144}, abstractNote={Increasing population and rural to urban migration are accelerating urbanization globally, permanently transforming natural systems over large extents. Modelling landscape change over large regions, however, presents particular challenges due to local-scale variations in social and environmental factors that drive land change. We simulated urban development across the South Atlantic States (SAS), a region experiencing rapid population growth and urbanization, using FUTURES—an open source land change model that uses demand for development, local development suitability factors, and a stochastic patch growing algorithm for projecting alternative futures of urban form and landscape change. New advances to the FUTURES modelling framework allow for high resolution projections over large spatial extents by leveraging parallel computing. We simulated the adoption of different urban growth strategies that encourage settlement densification in the SAS as alternatives to the region’s increasing sprawl. Evaluation of projected patterns indicate a 15% increase in urban lands by 2050 given a status quo development scenario compared to a 14.8% increase for the Infill strategy. Status quo development resulted in a 3.72% loss of total forests, 2.97% loss of highly suitable agricultural land, and 3.69% loss of ecologically significant lands. An alternative Infill scenario resulted in similar losses of total forest (3.62%) and ecologically significant lands (3.63%) yet consumed less agricultural lands (1.23% loss). Moreover, infill development patterns differed qualitatively from the status quo and resulted in less fragmentation of the landscape.}, number={10}, journal={Land}, publisher={MDPI AG}, author={Berkel, Derek Van and Shashidharan, Ashwin and Mordecai, Rua S. and Vatsavai, Raju and Petrasova, Anna and Petras, Vaclav and Mitasova, Helena and Vogler, John B. and Meentemeyer, Ross K.}, year={2019}, month={Sep}, pages={144} }
 @article{petrasova_hipp_mitasova_2019, title={Visualization of Pedestrian Density Dynamics Using Data Extracted from Public Webcams}, volume={8}, url={https://www.mdpi.com/2220-9964/8/12/559}, DOI={10.3390/ijgi8120559}, abstractNote={Accurate information on the number and distribution of pedestrians in space and time helps urban planners maintain current city infrastructure and design better public spaces for local residents and visitors. Previous studies have demonstrated that using webcams together with crowdsourcing platforms to locate pedestrians in the captured images is a promising technique for analyzing pedestrian activity. However, it is challenging to efficiently transform the time series of pedestrian locations in the images to information suitable for geospatial analytics, as well as visualize data in a meaningful way to inform urban design or decision making. In this study, we propose to use a space-time cube (STC) representation of pedestrian data to analyze the spatio-temporal patterns of pedestrians in public spaces. We take advantage of AMOS (The Archive of Many Outdoor Scenes), a large database of images captured by thousands of publicly available, outdoor webcams. We developed a method to obtain georeferenced spatio-temporal data from webcams and to transform them into high-resolution continuous representation of pedestrian densities by combining bivariate kernel density estimation with trivariate, spatio-temporal spline interpolation. We demonstrate our method on two case studies analyzing pedestrian activity of two city plazas. The first case study explores daily and weekly spatio-temporal patterns of pedestrian activity while the second one highlights the differences in pattern before and after plaza’s redevelopment. While STC has already been used to visualize urban dynamics, this is the first study analyzing the evolution of pedestrian density based on crowdsourced time series of pedestrian occurrences captured by webcam images.}, number={12}, journal={ISPRS International Journal of Geo-Information}, publisher={MDPI AG}, author={Petrasova, Anna and Hipp, J. Aaron and Mitasova, Helena}, year={2019}, month={Dec}, pages={559} }
 @article{harmon_mitasova_petrasova_petras_2019, title={r.sim.terrain 1.0: a landscape evolution model with dynamic hydrology}, volume={12}, ISSN={["1991-9603"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85068763744&partnerID=MN8TOARS}, DOI={10.5194/gmd-12-2837-2019}, abstractNote={Abstract. While there are numerical landscape evolution models
that simulate how steady-state flows of water and sediment
reshape topography over long periods of time,
r.sim.terrain is the first to
simulate short-term topographic change
for both steady-state and dynamic flow regimes
across a range of spatial scales.
This free and open-source
Geographic Information Systems (GIS)-based topographic evolution model
uses empirical models for soil erosion
and a physics-based model
for shallow overland water flow and soil erosion
to compute short-term topographic change.
This model uses either a steady-state
or unsteady representation of overland flow
to simulate how overland sediment mass flows reshape topography
for a range of hydrologic soil erosion regimes
based on topographic, land cover, soil, and rainfall parameters.
As demonstrated by a case study
for the Patterson Branch subwatershed
on the Fort Bragg military installation in North Carolina,
r.sim.terrain simulates the development of
fine-scale morphological features including
ephemeral gullies, rills, and hillslopes.
Applications include land management, erosion control,
landscape planning, and landscape restoration.
}, number={7}, journal={GEOSCIENTIFIC MODEL DEVELOPMENT}, author={Harmon, Brendan Alexander and Mitasova, Helena and Petrasova, Anna and Petras, Vaclav}, year={2019}, month={Jul}, pages={2837–2854} }
 @article{harmon_mitasova_petrasova_petras_2019, title={r.sim.terrain: a dynamic landscape evolution model}, volume={2}, DOI={10.5194/gmd-2019-18}, abstractNote={Abstract. While there are numerical landscape evolution models that simulate how steady state flows of water and sediment reshape topography over long periods of time, r.sim.terrain is the first to simulate short-term topographic change for both steady state and dynamic flow regimes across a range of spatial scales. This free and open source, GIS-based topographic evolution model uses empirical models for soil erosion at watershed to regional scales and a physics-based model for shallow overland water flow and soil erosion at subwatershed scales to compute short-term topographic change. This either steady state or dynamic model simulates how overland sediment mass flows reshape topography for a range of hydrologic soil erosion regimes based on topographic, land cover, soil, and rainfall parameters. As demonstrated by a case study for Patterson Branch subwatershed on the Fort Bragg military installation in North Carolina, r.sim.terrain can realistically simulate the development of fine-scale morphological features including ephemeral gullies, rills, and hillslopes. Applications include land management, erosion control, landscape planning, and landscape restoration.
}, publisher={Copernicus GmbH}, author={Harmon, Brendan Alexander and Mitasova, Helena and Petrasova, Anna and Petras, Vaclav}, year={2019}, month={Feb} }
 @article{vukomanovic_singh_petrasova_vogler_2018, title={Not seeing the forest for the trees: Modeling exurban viewscapes with LiDAR}, volume={170}, ISSN={["1872-6062"]}, DOI={10.1016/j.landurbplan.2017.10.010}, abstractNote={Viewscapes are the visible portions of a landscape that create a visual connection between a human observer and their 3-dimensional surroundings. However, most large area line-of-sight studies have modeled viewscapes using bare-earth digital elevation models, which exclude the 3-D elements of built and natural environments needed to comprehensively understand the scale, complexity and naturalness of an area. In this study, we compared viewscapes derived from LiDAR bare earth (BE) and top-of-canopy (ToC) surface models for 1000 exurban homes in a region of the Rocky Mountains, USA that is experiencing rapid low-density growth. We examined the extent to which the vertical structure of trees and neighboring houses in ToC models – not accounted for in BE models – affect the size and quality of each home’s viewscape. ToC models consistently produced significantly smaller viewscapes compared to BE models across five resolutions of LiDAR-derived models (1, 5, 10, 15, and 30-m). As resolution increased, both ToC and BE models produced increasingly larger, exaggerated viewscapes. Due to their exaggerated size, BE models overestimated the greenness and diversity of vegetation types in viewscapes and underestimated ruggedness of surrounding terrain compared to more realistic ToC models. Finally, ToC models also resulted in more private viewscapes, with exurban residents seeing almost three times fewer neighbors compared to BE models. These findings demonstrate that viewscape studies should consider both vertical and horizontal dimensions of built and natural environments in landscape and urban planning applications.}, journal={LANDSCAPE AND URBAN PLANNING}, author={Vukomanovic, Jelena and Singh, Kunwar K. and Petrasova, Anna and Vogler, John B.}, year={2018}, month={Feb}, pages={169–176} }
 @article{millar_tabrizian_petrasova_petras_harmon_mitasova_meentemeyer_2018, title={Tangible Landscape: A Hands-on Method for Teaching Terrain Analysis}, volume={2018-April}, url={http://dx.doi.org/10.1145/3173574.3173954}, DOI={10.1145/3173574.3173954}, abstractNote={This paper presents novel and effective methods for teaching about topography--or shape of terrain--and assessing 3-dimensional spatial learning using tangibles. We used Tangible Landscape--a tangible interface for geospatial modeling--to teach multiple hands-on tangible lessons on the concepts of grading (i.e., earthwork), geomorphology, and hydrology. We examined students' ratings of the system's usability and user experience and tested students' acquisition and transfer of knowledge. Our results suggest the physicality of the objects enabled the participants to effectively interact with the system and each other, positively impacting ratings of usability and task-specific knowledge building. These findings can potentially advance the design and implementation of tangible teaching methods for the topics of geography, design, architecture, and engineering.}, journal={Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems  - CHI '18}, author={Millar, G.C. and Tabrizian, P. and Petrasova, A. and Petras, V. and Harmon, B. and Mitasova, H. and Meentemeyer, R.K.}, year={2018}, month={Apr} }
 @book{petrasova_harmon_petras_tabrizian_mitasova_2018, title={Tangible Modeling with Open Source GIS}, DOI={10.1007/978-3-319-89303-7}, abstractNote={This book presents a new type of modeling environment where users interact with geospatial simulations using 3D physical models of studied landscapes.}, publisher={Springer International Publishing}, author={Petrasova, Anna and Harmon, Brendan and Petras, Vaclav and Tabrizian, Payam and Mitasova, Helena}, year={2018} }
 @article{harmon_petrasova_petras_mitasova_meentemeyer_2018, title={Tangible topographic modeling for landscape architects}, volume={16}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85044342339&partnerID=MN8TOARS}, DOI={10.1177/1478077117749959}, abstractNote={We present Tangible Landscape—a technology for rapidly and intuitively designing landscapes informed by geospatial modeling, analysis, and simulation. It is a tangible interface powered by a geographic information system that gives three-dimensional spatial data an interactive, physical form so that users can naturally sense and shape it. Tangible Landscape couples a physical and a digital model of a landscape through a real-time cycle of physical manipulation, three-dimensional scanning, spatial computation, and projected feedback. Natural three-dimensional sketching and real-time analytical feedback should aid landscape architects in the design of high performance landscapes that account for physical and ecological processes. We conducted a series of studies to assess the effectiveness of tangible modeling for landscape architects. Landscape architecture students, academics, and professionals were given a series of fundamental landscape design tasks—topographic modeling, cut-and-fill analysis, and water flow modeling. We assessed their performance using qualitative and quantitative methods including interviews, raster statistics, morphometric analyses, and geospatial simulation. With tangible modeling, participants built more accurate models that better represented morphological features than they did with either digital or analog hand modeling. When tangibly modeling, they worked in a rapid, iterative process informed by real-time geospatial analytics and simulations. With the aid of real-time simulations, they were able to quickly understand and then manipulate how complex topography controls the flow of water.}, number={1}, journal={International Journal of Architectural Computing}, author={Harmon, B. A. and Petrasova, Anna and Petras, Vaclav and Mitasova, Helena and Meentemeyer, R.}, year={2018}, pages={4–21} }
 @article{pickard_van berkel_petrasova_meentemeyer_2017, title={Forecasts of urbanization scenarios reveal trade-offs between landscape change and ecosystem services}, volume={32}, ISSN={["1572-9761"]}, DOI={10.1007/s10980-016-0465-8}, abstractNote={Expansion of urban settlements has caused observed declines in ecosystem services (ES) globally, further stressing the need for informed urban development and policies. Incorporating ES concepts into the decision making process has been shown to support resilient and functional ecosystems. Coupling land change and ES models allows for insights into the impacts and anticipated trade-offs of specific policy decisions. The spatial configuration of urbanization likely influences the delivery and production of ES. When considering multiple ES simultaneously, improving the production of one ecosystem service often results in the decrease in the provision of other ES, giving rise to trade-offs. We examine the impact of three urban growth scenarios on several ES to determine the degree to which spatial configuration of urbanization and the development of natural land cover impacts these services over 25 years. We couple land change and ES models to examine impacts to carbon sequestration, surface water-run off, nitrogen and phosphorus export, organic farming and camping site suitability, to determine trade-offs among the six ES associated with each spatial configuration for western North Carolina. Consequences of urban configurations are dramatic, with degraded ES across all scenarios and substantial variation depending on urban pattern, revealing trade-offs. Counter-intuitive trade-offs between carbon sequestration and lands available for organic farming and camping were observed, suggesting that no configurations result in mutual benefits for all ES. By understanding trade-offs associated with urban configurations, decision makers can identify ES critical to an area and promote configurations that enhance those.}, number={3}, journal={LANDSCAPE ECOLOGY}, author={Pickard, Brian R. and Van Berkel, Derek and Petrasova, Anna and Meentemeyer, Ross K.}, year={2017}, month={Mar}, pages={617–634} }
 @article{fusion of high-resolution dems for water flow modeling_2017, url={http://dx.doi.org/10.1186/s40965-017-0019-2}, DOI={10.1186/s40965-017-0019-2}, abstractNote={New technologies for terrain reconstruction have increased the availability of topographic data at a broad range of resolutions and spatial extents. The existing digital elevation models (DEMs) can now be updated at a low cost in selected study areas with newer, often higher resolution data using unmanned aerial systems (UAS) or terrestrial sensors. However, differences in spatial coverage and levels of detail often create discontinuities along the newly mapped area boundaries and subsequently lead to artifacts in results of DEM analyses or models of landscape processes. To generate a seamless updated DEM, we propose a generalized approach to DEM fusion with a smooth transition while preserving important topographic features. The transition is controlled by distance-based weighted averaging along the DEMs’ blending overlap with spatially variable width based on elevation differences. We demonstrate the method on two case studies exploring the effects of DEM fusion on water flow modeling in the context of precision agriculture. In the first case study, we update a lidar-based DEM with a fused set of two digital surface models (DSMs) derived from imagery acquired by UAS. In the second application, developed for a tangible geospatial interface, we fuse a georeferenced, physical sand model continuously scanned by a Kinect sensor with a lidar-based DEM of the surrounding watershed in order to computationally simulate and test methods for controlling storm water flow. The results of our experiments demonstrate the importance of seamless, robust fusion for realistic simulation of water flow patterns using multiple high-resolution DEMs.}, journal={Open Geospatial Data, Software and Standards}, year={2017}, month={Dec} }
 @article{generalized 3d fragmentation index derived from lidar point clouds_2017, url={http://dx.doi.org/10.1186/s40965-017-0021-8}, DOI={10.1186/s40965-017-0021-8}, abstractNote={Point clouds with increased point densities create new opportunities for analyzing landscape structure in 3D space. Taking advantage of these dense point clouds we have extended a 2D forest fragmentation index developed for regional scale analyses into a 3D index for analyzing vegetation structure at a much finer scale. Based on the presence or absence of points in a 3D raster (voxel model) the 3D fragmentation index is used to evaluate the configuration of a cell's 3D neighborhood resulting in fragmentation classes such as interior, edge, or patch. In order to incorporate 3D fragmentation into subsequent conventional 2D analyses, we developed a transformation of this 3D fragmentation index into a series of 2D rasters based on index classes. We applied this method to a point cloud obtained by airborne lidar capturing a suburban area with mixed forest cover. All processing and visualization was done in GRASS GIS, an open source, geospatial processing and remote sensing tool. The newly developed code is also publicly available and open source. The entire processing chain is available and executable through Docker for maximum reproducibility. We demonstrated that this proposed index can be used to describe different types of vegetation structure making it a promising tool for remote sensing and landscape ecology. Finally, we suggest that processing point clouds using 3D raster methods including 3D raster algebra is as straightforward as using well-established 2D raster and image processing methods.}, journal={Open Geospatial Data, Software and Standards}, year={2017}, month={Dec} }
 @article{rocchini_petras_petrasova_horning_furtkevicova_neteler_leutner_wegmann_2017, title={Open data and open source for remote sensing training in ecology}, volume={40}, ISSN={["1878-0512"]}, DOI={10.1016/j.ecoinf.2017.05.004}, abstractNote={Remote sensing is one of the most important tools in ecology and conservation for an effective monitoring of ecosystems in space and time. Hence, a proper training is crucial for developing effective conservation practices based on remote sensing data. In this paper we aim to highlight the potential of open access data and open source software and the importance of the inter-linkages between these and remote sensing training, with an interdisciplinary perspective. We will first deal with the importance of open access data and then we provide several examples of Free and Open Source Software (FOSS) for a deeper and more critical understanding of its application in remote sensing.}, journal={ECOLOGICAL INFORMATICS}, author={Rocchini, Duccio and Petras, Vaclav and Petrasova, Anna and Horning, Ned and Furtkevicova, Ludmila and Neteler, Markus and Leutner, Benjamin and Wegmann, Martin}, year={2017}, month={Jul}, pages={57–61} }
 @article{rocchini_petras_petrasova_chemin_ricotta_frigeri_landa_marcantonio_bastin_metz_et al._2017, title={Spatio-ecological complexity measures in GRASS GIS}, volume={104}, ISSN={["1873-7803"]}, DOI={10.1016/j.cageo.2016.05.006}, abstractNote={Good estimates of ecosystem complexity are essential for a number of ecological tasks: from biodiversity estimation, to forest structure variable retrieval, to feature extraction by edge detection and generation of multifractal surface as neutral models for e.g. feature change assessment. Hence, measuring ecological complexity over space becomes crucial in macroecology and geography. Many geospatial tools have been advocated in spatial ecology to estimate ecosystem complexity and its changes over space and time. Among these tools, free and open source options especially offer opportunities to guarantee the robustness of algorithms and reproducibility. In this paper we will summarize the most straightforward measures of spatial complexity available in the Free and Open Source Software GRASS GIS, relating them to key ecological patterns and processes.}, journal={COMPUTERS & GEOSCIENCES}, author={Rocchini, Duccio and Petras, Vaclav and Petrasova, Anna and Chemin, Yann and Ricotta, Carlo and Frigeri, Alessandro and Landa, Martin and Marcantonio, Matteo and Bastin, Lucy and Metz, Markus and et al.}, year={2017}, month={Jul}, pages={166–176} }
 @article{tonini_shoemaker_petrasova_harmon_petras_cobb_mitasova_meentemeyer_2017, title={Tangible geospatial modeling for collaborative solutions to invasive species management}, volume={92}, ISSN={["1873-6726"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85014320386&partnerID=MN8TOARS}, DOI={10.1016/j.envsoft.2017.02.020}, abstractNote={Managing landscape-scale environmental problems, such as biological invasions, can be facilitated by integrating realistic geospatial models with user-friendly interfaces that stakeholders can use to make critical management decisions. However, gaps between scientific theory and application have typically limited opportunities for model-based knowledge to reach the stakeholders responsible for problem-solving. To address this challenge, we introduce Tangible Landscape, an open-source participatory modeling tool providing an interactive, shared arena for consensus-building and development of collaborative solutions for landscape-scale problems. Using Tangible Landscape, stakeholders gather around a geographically realistic 3D visualization and explore management scenarios with instant feedback; users direct model simulations with intuitive tangible gestures and compare alternative strategies with an output dashboard. We applied Tangible Landscape to the complex problem of managing the emerging infectious disease, sudden oak death, in California and explored its potential to generate co-learning and collaborative management strategies among actors representing stakeholders with competing management aims.}, journal={ENVIRONMENTAL MODELLING & SOFTWARE}, author={Tonini, Francesco and Shoemaker, Douglas and Petrasova, Anna and Harmon, Brendan and Petras, Vaclav and Cobb, Richard C. and Mitasova, Helena and Meentemeyer, Ross K.}, year={2017}, month={Jun}, pages={176–188} }
 @article{tabrizian_petrasova_harmon_petras_mitasova_meentemeyer_2016, title={Immersive Tangible Geospatial Modeling}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85011015621&partnerID=MN8TOARS}, DOI={10.1145/2996913.2996950}, abstractNote={Tangible Landscape is a tangible interface for geographic information systems (GIS). It interactively couples physical and digital models of a landscape so that users can intuitively explore, model, and analyze geospatial data in a collaborative environment. Conceptually Tangible Landscape lets users hold a GIS in their hands so that they can feel the shape of the topography, naturally sculpt new landforms, and interact with simulations like water flow. Since it only affords a bird's-eye view of the landscape, we coupled it with an immersive virtual environment so that users can virtually walk around the modeled landscape and visualize it at a human-scale. Now as users shape topography, draw trees, define viewpoints, or route a walkthrough, they can see the results on the projection-augmented model, rendered on a display, or rendered on a head-mounted display. In this paper we present the Tangible Landscape Immersive Extension, describe its physical setup and software architecture, and demonstrate its features with a case study.}, journal={24TH ACM SIGSPATIAL INTERNATIONAL CONFERENCE ON ADVANCES IN GEOGRAPHIC INFORMATION SYSTEMS (ACM SIGSPATIAL GIS 2016)}, author={Tabrizian, Payam and Petrasova, Anna and Harmon, Brendan and Petras, Vaclav and Mitasova, Helena and Meentemeyer, Ross}, year={2016} }
 @inproceedings{jeziorska_mitasova_petrasova_petras_divakaran_zajkowski_2016, title={Overland flow analysis using time series of sUAS- derived elevation models}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84979525774&partnerID=MN8TOARS}, DOI={10.5194/isprs-annals-iii-8-159-2016}, abstractNote={Abstract. With the advent of the innovative techniques for generating high temporal and spatial resolution terrain models from Unmanned Aerial Systems (UAS) imagery, it has become possible to precisely map overland flow patterns. Furthermore, the process has become more affordable and efficient through the coupling of small UAS (sUAS) that are easily deployed with Structure from Motion (SfM) algorithms that can efficiently derive 3D data from RGB imagery captured with consumer grade cameras. We propose applying the robust overland flow algorithm based on the path sampling technique for mapping flow paths in the arable land on a small test site in Raleigh, North Carolina. By comparing a time series of five flights in 2015 with the results of a simulation based on the most recent lidar derived DEM (2013), we show that the sUAS based data is suitable for overland flow predictions and has several advantages over the lidar data. The sUAS based data captures preferential flow along tillage and more accurately represents gullies. Furthermore the simulated water flow patterns over the sUAS based terrain models are consistent throughout the year. When terrain models are reconstructed only from sUAS captured RGB imagery, however, water flow modeling is only appropriate in areas with sparse or no vegetation cover.}, number={8}, booktitle={International archives of the photogrammetry remote sensing and spatial}, author={Jeziorska, J. and Mitasova, Helena and Petrasova, Anna and Petras, Vaclav and Divakaran, D. and Zajkowski, T.}, year={2016}, pages={159–166} }
 @inproceedings{harmon_petrasova_petras_mitasova_meentemeyer_2016, title={Tangible landscape: cognitively grasping the flow of water}, volume={41}, DOI={10.5194/isprs-archives-xli-b2-647-2016}, abstractNote={Abstract. Complex spatial forms like topography can be challenging to understand, much less intentionally shape, given the heavy cognitive load of visualizing and manipulating 3D form. Spatiotemporal processes like the flow of water over a landscape are even more challenging to understand and intentionally direct as they are dependent upon their context and require the simulation of forces like gravity and momentum. This cognitive work can be offloaded onto computers through 3D geospatial modeling, analysis, and simulation. Interacting with computers, however, can also be challenging, often requiring training and highly abstract thinking. Tangible computing – an emerging paradigm of human-computer interaction in which data is physically manifested so that users can feel it and directly manipulate it – aims to offload this added cognitive work onto the body. We have designed Tangible Landscape, a tangible interface powered by an open source geographic information system (GRASS GIS), so that users can naturally shape topography and interact with simulated processes with their hands in order to make observations, generate and test hypotheses, and make inferences about scientific phenomena in a rapid, iterative process. Conceptually Tangible Landscape couples a malleable physical model with a digital model of a landscape through a continuous cycle of 3D scanning, geospatial modeling, and projection. We ran a flow modeling experiment to test whether tangible interfaces like this can effectively enhance spatial performance by offloading cognitive processes onto computers and our bodies. We used hydrological simulations and statistics to quantitatively assess spatial performance. We found that Tangible Landscape enhanced 3D spatial performance and helped users understand water flow.}, number={B2}, booktitle={International archives of the photogrammetry remote sensing and spatial}, author={Harmon, B. A. and Petrasova, Anna and Petras, Vaclav and Mitasova, Helena and Meentemeyer, K.}, year={2016}, pages={647–653} }
 @article{petras_petrasova_harmon_meentemeyer_mitasova_2015, title={Integrating Free and Open Source Solutions into Geospatial Science Education}, volume={4}, ISSN={["2220-9964"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84948970902&partnerID=MN8TOARS}, DOI={10.3390/ijgi4020942}, abstractNote={While free and open source software becomes increasingly important in geospatial research and industry, open science perspectives are generally less reflected in universities’ educational programs. We present an example of how free and open source software can be incorporated into geospatial education to promote open and reproducible science. Since 2008 graduate students at North Carolina State University have the opportunity to take a course on geospatial modeling and analysis that is taught with both proprietary and free and open source software. In this course, students perform geospatial tasks simultaneously in the proprietary package ArcGIS and the free and open source package GRASS GIS. By ensuring that students learn to distinguish between geospatial concepts and software specifics, students become more flexible and stronger spatial thinkers when choosing solutions for their independent work in the future. We also discuss ways to continually update and improve our publicly available teaching materials for reuse by teachers, self-learners and other members of the GIS community. Only when free and open source software is fully integrated into geospatial education, we will be able to encourage a culture of openness and, thus, enable greater reproducibility in research and development applications.}, number={2}, journal={ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION}, author={Petras, Vaclav and Petrasova, Anna and Harmon, Brendan and Meentemeyer, Ross K. and Mitasova, Helena}, year={2015}, month={Jun}, pages={942–956} }