GEOG 551: Principles of Remote Sensing

Exercise #8

Remote Sensing of Water Resources


Due Date: November 28, 2006


Objectives

  • To understand and identify considerations when remote sensing water resources.
  • Become familiar with several practical remote sensing water resource applications.

Remote sensing and GIS technologies offer a wide range of applications suitable for water resource investigation. Among these, the capability of discriminating among different land cover types using aircraft and satellite imagery is one of the most important. Cover classes may be identified for their significance to processes such as runoff yield, interception, and evapotranspiration. This type of information is useful for modeling basin-wide components of the water budget. Basin and channel features influence runoff and sedimentation in a watershed. GIS spatial analytic techniques can quantify such characteristics as slope, aspect, channel length, and drainage density. Low-altitude aerial photographs can be used to monitor changes in channel geometry over time.

Remote sensing and GIS are also useful for groundwater investigations. On a regional level, satellite imagery can be examined to define watershed boundaries, fracture zones, drainage patterns, and other features of hydrogeologic significance. Stereo-viewing of large-scale aerial photography for relief and vegetation patterns, in conjunction with ground-referencing techniques, can provide valuable insights for localized studies. In some cases, airborne imagery can be used to locate seeps and springs.


Evaluating Impacts of Hurricane Floyd

Hurricane Floyd churned the coastal waterways of North Carolina like a spoon in a mixing bowl. Following Floyd, record breaking rains continued to soak the area, washing mountains of sediment and waste into the water system. Rivers and tributaries along the Atlantic became choked, and major ecological changes happened as evidenced in the SeaWifs images below. Levels of dissolved oxygen in the water dropped dramatically as organic matter decomposed, and aquatic life was threatened in dozens of estuaries and peripheral habitats. For people living in the region, the flood that began with Floyd was just the beginning. As illustrated in the following images, the changes to the area since this rainy season began affected hundreds of thousands of people.


Sept. 16, 1999

Sept. 17, 1999

Sept. 23, 1999

Oct. 26, 1999

From space, Landsat 7 captured the massive flow of sedimentation and waste runoff in the area most affected by flooding. Notice the dark coloration in the engorged waterways, indicating heavy concentrations of organic material that was washed into the water system.


Sept. 23, 1999

Sept. 23, 1999

Sept. 23, 1999

Courtesy of NASA's Scientific Visualization Studio.


ASSIGNMENT





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Last Modified: 12 January 2005