Remote sensing: snow monitoring tool for today and tomorrow

Although still a developing technology, remote sensing from airplanes and satellites is proving to be a unique means for monitoring snow characteristcs over large areas. The results of an ongoing quasi-operational test of satellite-derived snow-covered area (SCA) in snowmelt runoff prediction methods by three state and six federal water agencies are reviewed. Early indications are that the inclusion of SCA can result in a significant reduction of runoff forecast error on specific watersheds. In order to further improve forecasts, research is underway at Steamboat Springs, Colorado to exploit microwave capabilities for the eventual remote determination of snow water equivalent, depth, and free water content. Both active and passive microwave systems are being tested to determine the appropriate sensors for future operational aircraft and spacecraft platforms. A futuristic look at a total snow monitoring system that will eventually lead to improved management of our snow resources is provided. This system will incorporate rapid data relay and processing, remote sensing from a variety of satellites supplemented by low and high altitude aircraft, and improvements in ground-based snow measurement technology.