Grand Canyon National Park (GRCA) makes extensive use of remotely sensed imagery and other data for planning, visualizing, mapping, analyzing, and managing resources in nearly every park program. Some of these uses include:
Grand Canyon staff and contractors used imagery from the USDA NAIP program and Landsat imagery to map vegetation in the inner canyon. A time series of Landsat images was used to generate life-form maps (deciduous versus evergreen; woodlands versus shrublands versus grasslands). Using Regression Tree methods followed by iterations of field checks and editing the NAIP imagery resulted in a classification of National Vegetation Classification Standard plant Associations. These methods are primarily computer-based with little human input, which within one year, allowed over 650,000 acres to be mapped into 39 map classes with an accuracy of 75percent. This level of accuracy and speed is unprecedented in the NPS – USGS Vegetation Mapping Program. As a result, these methods are being promoted as the new standard for inventory of large NPS units.
Additional applications of imagery include:
- GRCA relies on high-spatial resolution (18-cm) ortho-rectified aerial photography to monitor campsites and use areas in accordance with the Colorado River Management Plan. The imagery is used as a base for mapping use areas, camping areas, facilities, individual campsites, vegetation, and resource impacts, as well as change detection over time.
- GRCA routinely uses high-resolution (30-cm) remotely-sensed orthophotography, Digital Elevation Model data (DEM) and lidar for mapping transportation features (trails, roads, parking areas). DEM data are also used for modeling trail gradients to estimate maintenance needs and costs.
- GRCA makes extensive use of remotely sensed data for major planning efforts, including the Backcountry Management Plan (BCMP). Aerial and satellite imagery is used for delineation of Backcountry Use Areas and Alternative development and visualization, and will be critical for evaluating plan alternatives for the Environmental Impact Statement. GRCA maintains an interactive Web map with remotely sensed imagery to convey information about the planning process, generate custom maps, and solicit feedback from stakeholders.
- Digital Elevation Model (DEM) data and Digital Orthophotography are helping NPS staff to delineate the park boundary where it is defined by geographic features, such as the canyon rim.
- Highly accurate and detailed geodatabases of buildings and other infrastructure are made possible through the use of high-resolution (30-cm) imagery of the park developed areas.
- Karst features play a major role in the groundwater hydrology of the Grand Canyon. Near the North Rim developed area, karst features are being mapped through the use of high-resolution imagery and lidar, enhancing the understanding of important hydrologic processes that effect groundwater, springs and seeps, and other water features.
- As part of an effort to minimize human-elk incidents and resource damage from elk in developed areas, lawns in the developed areas of the park were quickly mapped through the use of high-resolution (30-cm) digital orthophotography.
GRCA uses satellite based Moderate Resolution Imaging Spectroradiometer (MODIS) data for burn severity modeling.