Hydrologic Impacts of Fuel-Reduction Treatments in the Hat and Burney Creek Basin

Abstract:

Fuel-reduction treatments are commonly employed throughout the western United States to improve forest health and/or decrease the risk of wildland fires. Periods of prolonged drought and high temperatures increase both the risk of wildland fires and the stress on water resources. Forest managers may mitigate the risk of wildland fires by increasing fuel-reduction treatments but the subsequent effect on forest hydrology and water resources is not well understood. Of particularly interest to water resources is the effect on snow pack accumulation and melt timing, which is impacted by forest cover. As part of a Comprehensive Forest Landscape Restoration Program (CFLRP), four sites were selected in the Hat Creek Basin of Lassen National Forest to study the hydrologic effects of two common fuel-reduction strategies, forest thinning and group selection. During the 2013/2014 winter, California experienced a significant drought, including a near-absence of continuous snow cover. Therefore, the effect on snow accumulation and melt timing during the 13/14 winter was not directly measured. However, significant deviations in solar radiation, wind speed, and solar moisture were observed in the data, suggesting fuel reduction treatments will have a tangible effect of snow pack and forest hydrology. Further work to examine the relationship between forest cover, fuel-treatments, and basin hydrology includes the analysis of historic stream flow data and the development of a hydro-ecological model for the basin.