Geovisual Analytics on the Web

Future Alternative Forest Ecosystem Scenarios (LANDIS-II Web Visualization)

The scenarios computed by LANDIS-II, the landscape model used for forest ecosystem simulations, are of high spatio-temporal complexity, which can be overwhelming for researchers and forest managers. We devise methods to expose the relevant information in a exploration portal on the web using a customized version of OpenLayers with WebGL.

This project is a collaborations with Dr. Robert Scheller and Dr. Melissa Lucash at the Portland State Dynamic Ecosystems and Landscapes Lab. It aims at modeling, analyzing and visualizing the behavior of forest ecosystems under different potential climate and forest management scenarios. US Forest Service personnel at the Chippewa National Forest, MN plan to take these scenarios into account when making future forest management decisions. This project is funded by the USDA Agriculture and Food Research Initiative.
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4D Statistical Surfaces for Change Detection in Large Spatio-temporal Datasets

4D statistical surfaces aims at improving the visual detection of change in time series. The method visualizes attribute values as surfaces, which are interpolated and animated over time; the interactive attribute surfaces are combined with color-coding and contour lines to support absolute and relative height judgment as well as faster perception and better location of change.

Time series simulation results of LANDIS-II, a modeling tool in forest ecology, as well as a temporal vegetation index dataset (NDVI) are visualized using 4D statistical surfaces. Usability challenges are addressed based on explorative interviews with a small group of users. The method is not limited to ecological model output; it can be used to create 3D temporal animations of arbitrary time series datasets where parameters are supplied in regular raster format.

Jenny, H.; Liem, J.; Lucash, M.S.; Scheller, R.M. (2014).
4-D Statistical Surface Method for Visual Change Detection in Forest Ecosystem Simulation Time Series
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of , vol.7, no.11, pp.4505–4511
doi: 10.1109/JSTARS.2014.2324972
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    4D Statistical Surface Animation
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    2D Map vs. 3D Statistical Surface
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    NDVI Statistical Surface (January and July)