Rainfall and runoff data: postfire soil hydrologic and biogeochemical response and recovery in northern California, USA

California’s wildfires are setting historic records for length, size, and severity (Safford and others, 2022, Kreider and others, 2024). These wildfires are altering soil processes like infiltration rates and carbon cycling over increasingly large areas (Staley and others, 2017; Kelly and others, 2020; Baur and others, 2024; Dow and others, 2024). In northern California, it is unclear how wildfire might increase runoff hazards or limit ecosystem recovery. To understand postfire soil response and recovery, we characterized the short and long-term effects of wildfire on soil infiltration and biogeochemical cycles using burned and nearby unburned sites. We seasonally conducted field measurements or collected soils for lab measurements to quantify soil hydrological and biogeochemical recovery for at least 3 years following the fire. Understanding the interaction between rocks, microbes, and water is key to identifying areas of elevated risk postfire and prioritizing postfire mitigation. Here are the rainfall data from five rain gages and runoff observations from across the 2020 LNU Lightning Complex, Walbridge, and Glass Fires and the 2021 Dixie Fire.

Tipping-bucket rain gages (RG) were installed at five sites (DIX-RG-08.csv, DIX-RG-09.csv, GLA-RG-03.csv, LNU-RG-02.csv, WAL-RG-01.csv) to continuously measure precipitation. The ‘Gage_ID’ reflects the corresponding fire and monitoring site location. The install date is noted in the file header after ‘Record_begin’, and the last data offload is after ‘Record_end’. Two Onset self-logging models were used, RG3 (0.01 in) and RG3-M (0.2 mm), that only differ by bucket capacity. The specific bucket volume is noted in the header after ‘Tip_volume_[unit]’. The data was manually offloaded during each site visit and combined into a single file that includes the ‘Event_id’, ‘Date_Time_GMT-[hours]’, ‘Rainfall_tip’, and ‘Other_event’. Each tip would need to be multiplied by the bucket volume and summed over the relevant time period to calculate either cumulative rainfall or rainfall intensities. The ‘Other_event’ column includes when the data was offloaded and other logger notes. The data released here were reviewed and corrected for inaccuracies due to equipment failure or logging inconsistencies. Dates of missing data due to equipment malfunction is noted in the header after ‘Missing records’.

Runoff observations (Runoff_summary.csv) were made during monitoring site visits across the 41 sites (31 burned, 10 unburned). Runoff observations are divided into two categories: ‘Sites with rills’ and ‘Sites with other evidence’. If there were sites with new rills since the last visit, where rills are typically ephemeral channelized runoff features less than ~0.5-m wide, it was noted by a yes (Y), no (N), or no data (nd) classification under ‘New rills’. No data was due to no clear denotation of the presence or absence of rills from field notes, test data, or photos. The columns for ‘Sites with rills’ and ‘Sites with other evidence’ name the sites with runoff observations. ‘Sites with other evidence’ would include observations of broad runoff features (for example, sheetwash or sheet erosion) or non-local rills (for example, upslope or downslope from the site but not within the monitoring area). The observations are separated by the three-letter ‘Fire’ abbreviation and the visit date ‘Month’ and ‘Year’.

For more information on the site locations and associated hydrological and biogeochemical data, refer to the project landing page: https://www.sciencebase.gov/catalog/item/680fa722d4be022940539f4d

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

References:
Baur, M.J., Friend, A.D., and Pellegrini, A.F.A., 2024, Widespread and systematic effects of fire on plant–soil water relations: Nature Geoscience, v. 17, no. 11, p. 1115–1120, at https://doi.org/10.1038/s41561-024-01563-6.

Dow, H.W., East, A.E., Sankey, J.B., Warrick, J.A., Kostelnik, J., Lindsay, D.N., and Kean, J.W., 2024, Postfire Sediment Mobilization and Its Downstream Implications Across California, 1984–2021: Journal of Geophysical Research: Earth Surface, v. 129, no. 8, at https://doi.org/10.1029/2024JF007725.

Kelly, L.T., Giljohann, K.M., Duane, A., Aquilué, N., Archibald, S., Batllori, E., Bennett, A.F., Buckland, S.T., Canelles, Q., Clarke, M.F., Fortin, M.-J., Hermoso, V., Herrando, S., Keane, R.E., and others, 2020, Fire and biodiversity in the Anthropocene: Science, v. 370, no. 6519, at https://doi.org/10.1126/science.abb0355.

Kreider, M.R., Higuera, P.E., Parks, S.A., Rice, W.L., White, N., and Larson, A.J., 2024, Fire suppression makes wildfires more severe and accentuates impacts of climate change and fuel accumulation: Nature Communications, v. 15, no. 1, p. 2412, at https://doi.org/10.1038/s41467-024-46702-0.

Safford, H.D., Paulson, A.K., Steel, Z.L., Young, D.J.N., and Wayman, R.B., 2022, The 2020 California fire season: A year like no other, a return to the past or a harbinger of the future? Global Ecology and Biogeography, v. 31, no. 10, p. 2005–2025, at https://doi.org/10.1111/geb.13498.

Staley, D.M., Negri, J.A., Kean, J.W., Laber, J.L., Tillery, A.C., and Youberg, A.M., 2017, Prediction of spatially explicit rainfall intensity–duration thresholds for post-fire debris-flow generation in the western United States: Geomorphology, v. 278, p. 149–162, at https://doi.org/10.1016/j.geomorph.2016.10.019.