Remote Sensing and Lake Management

Remotely sensed data collected by satellites can be utilized for lake management and water quality studies. Satellites, such as Landsat 7, collect data from the same location on the earth's surface every 16 days. The raw data can be processed in many ways to develop datasets ranging from land cover data to lake vegetation mapping. Landsat's frequent return period provides an excellent temporal as well as spatial data source.

True color composite image derived from bands 1,2, and 3 of an October 1999 Landsat 7 scene. Also shown are the watershed boundaries of the various Portage Lakes and City of Portage limits.

False Color composite using bands 2,3, and 4. Reds show healthy green vegetation while greens show barren areas.

False color composite using bands 3, 4, and 7. This composite enhances urban land covers in dark purple.

Raw satellite data can be processed in many different ways to extract different surface features. The upper left image shows satellite data processed into a 10 class land cover dataset. Further processing of the water areas enhances subtle reflectivity differences within each pixel as shown in the center image and upper right image. This remotely sensed data can then be used to make assessments of lake water quality and used in tracking aquatic nuisance species.