Simulation and evaluation of water yield response to vegetation management on a forested watershed in Arizona
AuthorHekman, Louis Harry,1945-
Committee ChairFogel, Martin M.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractA methodology is presented for evaluating timber clearing as a means for beneficially increasing water yields from forested watersheds. Stochastic models of temperature and precipitation are developed and used to generate long term synthetic records of rain, snow, snowmelt, and potential evaporation. A deterministic hydrologic watershed model transforms the synthetic climatic data into long term streamflow records reflecting the hydrologic effects of clearing selected percentages of watershed area, either on a permanent or rotational basis. The simulated streamflow regimes are then analyzed in relation to the impacted reservoir and water supply system. Evaluation categories discussed include timber and forage production, agricultural water supply, flooding, hydroelectric power production, and reservoir-based recreation. A 38.8 square mile watershed on the East Fork White River in east-central Arizona is used to illustrate the procedures developed in this study. Vegetation management alternatives modeled are permanent conversion of 0, 20, 33, 50, 67, and 100 percent of the watershed area, as well as periodic harvesting, with subsequent timber regrowth, of 20, 33, and 50 percent of the watershed area. A hypothetical reservoir system serves as the basis for evaluating a 250 year simulated streamflow record induced by each management option. All conversion activities result in increased streamflow, better ability to meet water demands, greater recreational activity, and more power production. However, potential for flood damage and wasted reservoir releases also increase. Depending on specific management objectives, the ultimate choice lies within the 20 to 50 percent range of permanent conversion activities.
Degree NamePh. D.
Degree ProgramRenewable Natural Resources