ECOSYSTEM DSS CASE STUDY

Fort AP Hill is a 76,000 acre Army training installation located in the Coastal Plan of Virginia. The mission of the environmental staff at Fort A.P. Hill is to create a sustainable, training environment for the US Army. Their approach is to create a proactive, sustainable forest management program that is based upon an “ecosystem” philosophy. By using an ecosystem approach, a more global perspective is maintained, ultimately serving both national security and ecological needs. Pursuant to this end, an ecologically oriented, spatially-enabled decision support system was created for the facility under contract to Space Imaging LLC, and named the EcoDSS. The core plaform for the EcoDSS is ArcGIS 8.x, with additional module development that integrates the spatial and attribute information with forest growth & yield models (Forest Vegetation Simulator), a silvicultural prescription system (Suppose), wildlife habitat indices (HSI), landscape structure fragmentation analysis (FRAGSTATS), and specific military applications such as Tactical Concealment Areas (TCA) analysis.

Particular to this article is the integration of 3-D visualization techniques into EcoDSS. 3D visualization is a critical need in multi-resource planning, and an underutilized methodology. Whenever there are conflicting resource requirements, 3D visualization could be an important part of the solution. In this case, the conflicts are easy to identify. The training mission of the facility, which includes the operation of heavy equipment in the forest, and excessive human traffic and firearms use in forested areas, is in direct conflict with endangered species laws and other mandatory or voluntary ecological rules and regulations. Limitations on use imposed by Bald Eagles or sensitive wetland soils certainly impact the installation’s ability to train military personnel. 3D visualization techniques, when combined with other DSS tools, can help identify and ameliorate resource conflicts so the facility can meet all its objectives. The key objective was to tightly integrate the 3D visualization tools with the DSS growth and yield model (i.e. FVS) so that Fort AP Hill staff could visualize the effects of forest treatment prescriptions in the future.

3D Visualization Methodology

The EcoDSS utilizes the Visual Nature Studio software available from 3D Nature. The Fort AP Hill 3-D Forest application (Figure 1), is a custom VNS application developed by Space Imaging and 3D Nature. It allows the user to access the power of Visual Nature Studio via a single streamlined interface. With the 3-D visualization application, you can quickly and easily produce a realistic 3D visualization of your area of interest, including terrain, foliage, lighting, atmospherics and sky, for any time period that is represented in your DSS database. This temporal aspect permits users to see the future results of current decisions on the landscape in three dimensions. The 3D application is started from within the EcoDSS by selecting a specific time period for the simulation derived using FVS.

Figure 1: The Main DSS 3-D Visualization Interface.

The Fort AP Hill 3D application lets you specify a single Camera position for rendering a still image for the selected time period, or up to three key frame positions for rendering a flythrough animation. You can choose preset settings for lighting, atmosphere and sky. Finally, you can specify the image type, name, path and size; choose a vertical terrain scale; and render an image or animation sequence. A single custom interface was developed (Figure 1) to aid the user in defining their camera location and viewing parameters. High-resolution imagery (i.e. 1 meter infrared) is used as a map backdrop to guide the user in setting camera and target locations. The initial camera position is set automatically based on the map display within ArcMap at the time the 3D application was initiated. With a few simple clicks, and no prior VNS knowledge, the user can create a 3-D scene representing the growth and yield projection for that time period.

A critical component of any “nature” visualization is the digital representation of the vegetation. To ensure that the renderings were as realistic as possible, 3D tree symbols that match the major species types for the Fort AP Hill were developed as VNS ‘foliage ecosystems’ (Figure 2). The ‘ecosystem’ is the data model utilized within VNS that defines unique representations of vegetation and related characteristics. Digital photographs captured by Fort AP Hill staff were used to create the foliage symbols. During rendering, each species’ density is evaluated for each polygon using the stems per acre attribute value contained in the output period shapefile. If the density is found to exceed zero stems per acre, the height attribute value is used to scale the tree symbols. Based on the shapefile height value, an age class is selected that most closely represents the height value. Foliage images are then selected at random from the images for that species and age class. If only a single image exists, it is used in the rendering, however most species have multiple symbols available.. The availability of multiple images for a given age class provides greater visual variability in the final rendered scene.

Figure 2: Example of detailed foliage and ground cover symbology for a mixed Oak stand

Complete, accurate, detailed is a primary necessity in 3D visualization, as it is for most applications that deal with spatial phenomena. In addition to visual representations of the local vegetation, high-quality imagery, terrain and forest data all improve the realism of the visualizations. Virtually any type of imagery or terrain model can be utilized, but increased detail makes the rendered result more realistic. Specific forest attribute information (heights, densities, ages, etc.) is also important. Inaccurate, or extremely sparse mensurational data will result in less detailed or less realistic 3D renderings. Fort AP Hill has invested in a detailed spatial forest inventory that provides these advantages when applied towards ecological modeling and 3D representation.

The Fort AP Hill 3D Forest application window allows users to quickly create still or animated visualizations from the ArcGIS EcoDSS GeoDatabase. Various sets of conditions can be established and visualized, and the most appropriate results selected and saved for future use. The Fort AP Hill 3-D Forest application window includes options for choosing lighting by time of day, atmospheric condition, image output format, vertical terrain scale, camera location and look angle, and others. Different types of scene information can be selected by the user, and displayed on the rendering. While increasing the number of choices a user must make can create difficulties, this kind of flexibility is essential if complex, conflicting scenarios must be evaluated and long-term decisions made.

To demonstrate the results of 3D visualizations, examples from Fort AP Hill are presented. Each was created using the EcoDSS/3D Nature application with standard data available to the military installation’s personnel. Figure 3 presents a typical scenario where defined prescriptions may conflict with other land uses, such as riparian areas, training area uses, forestry harvesting and thinning activities, and other resource concerns. The region identified by the red rectangle represents an area of interest where these conflicts exist. The areas of concern are identified by red, hatched polygons. Note the conflict between the riparian area and the shelterwood prescription for the Poplar-Oak stand shown in brown. The conflict for the green dot represents a training navigation location. The green area represents a ”Grow Only” prescription commonly applied to non-pine stands.

Figure 3: EcoDSS ArcMap interface showing a forest prescription map with areas of concern.

Figure 4 presents 1 meter IKONOS false color imagery for the same area of interest. Pine stands are easily identified by their red tones. The green dots represent training navigation points. High-resolution imagery is utilized across the base for planning and operational purposes including military training and resource management.

Figure 4: EcoDSS ArcMap interface showing 1m IKONOS false color imagery and areas of concern.

Using the 3D application, the user can easily render a visualization of the current conditions. This is presented in Figure 5. Using the simple interface, the user can set the camera to provide as much plot or stand level detail as required, or generate landscape scale representations. The foreground stand to the right of the lake in the scene represents the poplar stand that is slated for shelterwood treatments. The foreground stand to the left is the free growth (i.e. no treatments) mixed oak areas. The background lighter green area represents the pine stands (background and immediate foreground in front of lake).

Figure 5: Detailed rendering of the AOI representing current conditions (year 0) Using the FVS output projections data, the user can easily generate 3D visualizations of future conditions.

Figure 6 represents conditions after 50 years. Note the growth of the pine stands. They did not have any treatments applied (free growth). Also, note the substantial change in the poplar stand to the right. This was previously a sparse mixed wood poplar stand. By applying a series of thinning and fertilization treatments it has evolved into a dense poplar stand.

Figure 6: Detailed rendering of the AOI representing projected conditions in 50 years.

Summary

The simplicity of the EcoDSS 3D application allows Fort AP Hill staff to quickly create visualizations of the growth and yield projections with minimal software training or VNS product knowledge. The ability to visualize in 3D at a landscape level helps staff better understand forest prescriptions and future impacts. With the rich capabilities found in the EcoDSS modeling tools, resource professionals at Fort AP Hill can now evaluate different prescription scenarios while working in concert with other resource management staff that have non-forestry objectives. It is hoped these tools will help Fort AP Hill meet environmental management goals as well as maintain their first class military training offerings.

The 3D visualization tool has already successfully been applied to help communicate changes to the landscape with military training personnel for future planned maneuver corridors. Continued use of the EcoDSS coupled with the 3D visualization application, supplemented by training and increase knowledge of applying forest prescriptions using FVS, will help forestry staff better communicate and evaluate treatment options and impacts in the future.