Geographic Information Systems (GIS) are computer software packages along with operating personnel that manage, process, and analyze large spatial datasets. GIS has provided the framework for new and innovative approaches to dealing with environmental problems. The task of managing and analyzing large spatial datasets has been simplified by this new technology allowing for more thorough and efficient environmental studies. Coupled with data collected through remote sensing methods, many different environmental variables can be measured and evaluated over large geographic areas for applications ranging from land cover mapping to water quality studies.
The images above were generated from a 1997 Landsat Thematic Mapper 5 satellite scene. Roll your cursor over the images to learn more about the processing and application of each.

3D Visualizations

A GIS also provides a means of displaying spatial data in unique ways. This three-dimensional animation shows a fly-over of the Kalamazoo River Watershed in southwest Michigan. The animation was derived from USGS Digital Elevation Models showing topographic relief. (Blue and purple colors represent higher terrain while greens and yellows represent lower.) Advanced visualization techniques are useful in analyzing and presenting complex spatial data.

One application of GIS and remote sensing which we have been exploring is in the generation of land use/land cover data from raw satellite data. Land use/land cover data are important for many different applications including planning, natural resource management, and hydrological studies. Traditional land use/land cover mapping methods are expensive and time consuming, making frequent updates cost prohibitive. Satellite-borne remote sensing platforms collect data constantly over most of the Earth's surface allowing volumes of data to be obtained at low costs. Advanced image processing can extract land use/land cover information from raw satellite data providing the opportunity for continual, cost-effective updates.

Traditional vector polygon representation of land use/land cover data.

Aerial photo base maps are digitized by hand and are assigned a land use/land cover designation by the interpreter.

Land use/land cover data derived from remotely sensed data

Advanced image processing groups data into land use/land cover categories using spectral signatures stored in raw satellite data.