Wildfire magnitude and frequency are increasing across the western US. These wildfires are drastically altering Earth’s surface by burning vegetation and surface soils and destabilizing hillslopes, making them more prone to erosion. Together, these alterations impact how precipitation and other material is transported to rivers. Rivers are the main conduit for transferring water and materials from headwaters further downstream and ultimately to oceans. However, given the challenges of capturing unpredictable wildfire events, there is a lack of understanding of the composition, concentration, and timing of material export out of watersheds immediately following fires. Included in the material being transported is soot and charcoal (called pyrogenic carbon) and essential nutrients, such as nitrogen. These materials are important for local ecosystem function, global biogeochemical cycles, and for the water quality of downstream drinking water resources. This study proposes to collect water and soil samples from burned watersheds following the fires of the Santa Clara Unit Lightning Complex. The watersheds were instrumented prior to the fires and provide an opportunity to analyze hydrologic and biochemical data previous to and after the fire. This study will generate data that will help to understand the impacts of wildfires on water resources used for drinking water purposes and provide valuable information for mitigation of these impacts.

The goal of this research is to reveal how altered hillslope hydrology and streamflow in newly burned landscapes will impact the in-stream storage and export of ecologically and biogeochemically critical material, with specific focus on nitrogen and pyrogenic carbon. This research will be conducted in a headwater catchment in central coastal California, which experiences non-perennial streamflow due to its Mediterranean climate. Researchers will couple measurements of nutrient and pyrogenic carbon concentrations at the outlets of five nested watersheds to assess how previously identified differences in dominant streamflow generation processes influence observed material transport. Through deployment of automated samplers and a spectrophotometer, this work will develop a rich dataset of in-stream pyrogenic carbon and nutrient concentrations from the very first post-fire precipitation event to the summer dry down. This is critical for constructing an integrative view of hydrologic and biogeochemical processes in fire- impacted watersheds. The project will provide train undergraduate and graduate students and generate data that will inform the Santa Clara Valley Water District on the export of materials from burned watershed into drinking water sources.

This project is jointly funded by the Hydrologic Sciences and Geobiology and Low-Temperature Geochemistry programs in the Division of Earth Sciences and the Ecosystem Science Cluster program in the Division of Environmental Biology.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Agency
National Science Foundation (NSF)
Institute
Division of Earth Sciences (EAR)
Type
Standard Grant (Standard)
Application #
2100269
Program Officer
Laura Lautz
Project Start
Project End
Budget Start
2020-11-15
Budget End
2021-10-31
Support Year
Fiscal Year
2021
Total Cost
$14,312
Indirect Cost
Name
Rensselaer Polytechnic Institute
Department
Type
DUNS #
City
Troy
State
NY
Country
United States
Zip Code
12180