This RAPID project focuses on production and delivery of dry ravel, a characteristic and immediate post-fire response on steep slopes in the western USA. Dry ravel arises from a dry-season transport process whereby gravel sediment moving down hillslopes by gravity becomes trapped by vegetation. This material provides a significant sediment source into river channels after wildfire in chaparral environments. The investigators will quantify the volume of dry ravel sediment deposited along channel margins as a result of the Springs Fire that burned Big Sycamore Canyon in southern California during May 2013. Terrestrial laser scanning before and after the rainy season (which typically begins around October 1) will capture initial changes in landscape topography. These data will be augmented by field surveys. Data collected during the first post-fire year are important for developing models of the dynamics of dry ravel. The investigators have geomorphic data spanning over 25 years for Big Sycamore Canyon and two comparable basins nearby with different fire histories--a tributary to north fork Matilija Creek that burned completely during the July 1985 Wheeler Fire-- and a tributary to Malibu Creek that has remained unburned. Comparing dry ravel processes at these three sites will enable a direct comparison of both short- and long-term sediment dynamics following wildfire in chaparral environments.
Developing a predictive understanding of both short- and long-term effects of wildfire is critical, especially in an era of changing climate that has increased frequencies and magnitudes of wildfires. Yet, accurately predicting post-fire effects remains elusive, and physically-based models of post-fire runoff and erosion are still being developed. The proposed project will integrate research and education by involving undergraduate students from California State University, Channel Islands (CSUCI). These students will pursue their capstone undergraduate coursework while assisting the PIs with field data collection and analysis. Two of these students are participants of the Hispanic-Serving Institutes ACCESO (Achieving a Cooperative College Education Through STEM Opportunities) Research Assistant Program on the CSUCI campus. These students will receive valuable research experiences including training in use of cutting-edge technologies.
