Abstract:
Lees than 10 percent of the annual precipitation in the southwestern United States is recovered for use by people. A large portion of the precipitation that is recovered originates on forested watersheds in
mountainous areas. Even here, 80 to 90 percent of the precipitation currently is not available for downstream users. Nevertheless, part of it potentially is available. However, before more precipitation can be recovered, water yields will have to be increased.
The possibility of increasing the amount of recoverable precipitation from forested watersheds appears greater for snow than for rain. Snow accumulates on forested sites throughout the winter, providing a reservoir of water potentially available for downstream use in the spring. If snowmelt water yields were increased significantly, additional water would be available to refill reservoirs or recharge groundwater aquifers.
A review of snow research in the southwestern United States over the past 25 years is presented to describe some of the possibilities for increasing snowmelt water yields. In large part, these research efforts have been aimed at the development of snow management guidelines for increasing the amount of recoverable water derived from snowpacks that accumulate and then melt on forested watersheds. Studies have been concerned with basic snow hydrology, forest management-snow relationships, and techniques of predicting effects of management on snowpack water yields.
