Submitted to: Remote Sensing in Hydrology and Water Management
Publication Type: Book / Chapter
Publication Acceptance Date: March 11, 2000
Publication Date: May 19, 2000
Interpretive Summary: Snow and ice are important sources of freshwater for a thirsty world, but they are difficult to measure, often being in remote and inaccessible regions. Remote sensing from aircraft and satellites has proven to provide the best way to obtain information on snow and ice in an economic way. Different portions of the electromagnetic spectrum show promise for measuring different properties--gamma radiation and microwave radiation fo snow water equivalent; visible radiation for snow cover extent. Operational techniques are rapidly becoming available in these areas, and government agencies and university scientists are using the data for input to snowmelt runoff models which are, in turn, used to forecast runoff in major river basins.
Snow and ice features can cover 44 percent of the world's land areas at any one time, and as such, can have significant effects on radiation exchange, hydrologic budget, and climate. Because of the large and remote regions covered, remote sensing of snow and ice has become the only way continuous monitoring can be done. Various portions of the electromagnetic spectrum have been successfully used. Gamma radiation is used for estimates of sno water equivalent in confined regions. Visible imagery is the most reliable approach for measuring the areal extent of snow cover. Passive microwave approaches have shown the most potential for snow water equivalent measurements over large areas. Both thermal infrared and active microwave approaches have significant potential, but are more difficult to analyze. Integration of data form two different sensors has a strong potential for increasing the information available about the snowpack.