Cooperative Watershed Management Research in the Lower Conifer Zone of California. First Progress Report, 1961-62.

摘要

Cooperative watershed management research in California's Lower Conifer Zone started July 1, 1961. The research is conducted by the Pacific Southwest Forest and Range Experiment Station of the U. S. Forest Service with the formal cooperation of the State of California, Department of Water Resources and the Division of Forestry. California's Lower Conifer Zone is a 12-1/2 million-acre commercial forest belt below the Snowpack Zone. Snow occurs in the Lower Conifer Zone, but rainfall rather than snow contributes more than half of the zone's streamflow in an average year (Colman,1955). Water is a major product. Thirty-two percent of the state's streamflow comes from this zone. The zone is providing about 80 percent of the State's annual timber harvest. Wildlife, livestock grazing, and increasing outdoor recreation make important local demands throughout the zone. Forest fire hazards are high, and fire protection and control are basic requirements. Mining has played a large role in creating bare soil areas, areas of dredging debris, and sediment loads in streams. The job of watershed management research is to conduct studies which will suggest better methods of management for water and predict the effects of a wide span of land management practices upon streamflow, water yield, and sedimentation. A program for watershed management research was prepared by Henry Anderson in 1960 (Anderson, 1960). In addition to predicting the consequences of existing and planned practices, research is aimed to find ways of managing Lower Conifer Zone watersheds to: 1. Increase total streamflow in all years, and especially in dry years. 2. Improve the timing of streamflow by reducing flood runoff and by reducing water losses in the late spring and summer. 3. Maintain water quality. 4. Minimize local floods and sedimentation. To meet these, watershed management research in the Lower Conifer Zone will take a four-pronged attack: 1. Inventories of present conditions of water yield, land conditions, soils, and flood potentials. 2. Basic studies of forest hydrology which will suggest methods of land management for improving water yield, preventing floods and controlling sediment. 3. Plot and small scale tests of management methods. 4. Pilot testing of watershed management alternatives on whole watersheds.