@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{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} }
 @inproceedings{harmon_2016, title={Embodied spatial thinking in tangible computing}, booktitle={Proceedings of the Tenth Anniversary Conference on Tangible Embedded and Embodied Interaction (TEI16)}, author={Harmon, B. A.}, year={2016}, pages={693–696} }
 @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} }
 @article{harmon_woerner_goldsmith_harmon_gardner_lyons_ogden_pribil_long_kern_et al._2016, title={Linking silicate weathering to riverine geochemistry-A case study from a mountainous tropical setting in west-central Panama}, volume={128}, ISSN={["1943-2674"]}, DOI={10.1130/b31388.1}, abstractNote={Chemical analyses from 71 watersheds across an ∼450 km transect in west-central Panama provide insight into controls on weathering and rates of chemical denudation and CO2 consumption across an igneous arc terrain in the tropics. Stream and river compositions across this region of Panama are generally dilute, having a total dissolved solute value = 118 ± 91 mg/L, with bicarbonate and silica being the predominant dissolved species. Solute, stable isotope, and radiogenic isotope compositions are consistent with dissolution of igneous rocks present in Panama by meteoric precipitation, with geochemical signatures of rivers largely acquired in their upstream regions. Comparison of a headwater basin with its entire watershed observed considerably more runoff production from the high-elevation upstream portion of the catchment than in its much more spatially extensive downstream region. Rock alteration profiles document that weathering proceeds primarily by dissolution of feldspar and pyroxene, with base cations effectively leached in the following sequence: Na > Ca > Mg > K. Control on water chemistry by bedrock lithology is indicated through a linking of elevated ([Na + K]/[Ca + Mg]) ratios in waters to a high proportion of catchment area silicic bedrock and low ratios to mafic bedrock. Sr-isotope ratios are dominated by basement-derived Sr, with only very minor, if any, contribution from other sources. Cation weathering of Casil + Mgsil + Na + K spans about an order in magnitude, from 3 to 32 tons/km2/yr. Strong positive correlations of chemical denudation and CO2 consumption are observed with precipitation, mean watershed elevation, extent of land surface forest cover, and physical erosion rate.}, number={11-12}, journal={GEOLOGICAL SOCIETY OF AMERICA BULLETIN}, author={Harmon, Russell S. and Woerner, Gerhard and Goldsmith, Steven T. and Harmon, Brendan A. and Gardner, Christopher B. and Lyons, W. Berry and Ogden, Fred L. and Pribil, Michael J. and Long, David T. and Kern, Zoltan and et al.}, year={2016}, month={Nov}, pages={1780–1812} }
 @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, A. 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} }