LOGGING EFFECTS ON STREAMFLOW - WATER YIELD AND SUMMER LOW FLOWS AT CASPAR CREEK IN NORTHWESTERN CALIFORNIA

Streamflow data for a 21‐year period were analyzed to determine the effects of selective tractor harvesting of second‐growth Douglas fir and redwood forest on the volume, timing, and duration of low flows and annual water yield in northwestern California. The flow response to logging was highly variable. Some of this variability was correlated with antecedent precipitation conditions. Statistically significant increases in streamflow were detected for both the annual period and the low‐flow season. Relative increases in water yield were greater for the summer low‐flow period than for annual flows, but these summer flow increases generally disappeared within 5 years. This paper is not subject to U.S. copyright. Published in 1990 by the American Geophysical Union.