Home   Login All Data Services Forum http://hydroportal.cuahsi.org/Holyfire/cuahsi_1_1.asmx?WSDL Holyfire James J. Guilinger jguil009@ucr.edu 303-549-2183 Website: https://andrewgray.ucr.edu/ 4 4 378,542 Download last tested on 11/26/2020 Last Harvested on 8/23/2020 1:42:45 PM(UTC) University of California, Riverside            Contact:        Sites: Values: Variables: 33.66906 -117.4372 -117.4409 33.66662

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Hydrologic monitoring data for headwaters burned in 2018 Holy Fire, southern California, USA Geographic Extent:

Abstract


Hydrologic monitoring data for headwaters burned in 2018 Holy Fire, Leach Canyon, Santa Ana Mountains, California, USA Rationale: Post-fire debris flows are particularly complex to study because they do not form discrete initiation locations and commonly involve multiple simultaneously operating erosional processes. Although recent work has begun to elucidate a more mechanistic understanding of post-fire debris flows, there is still a paucity of detailed sediment budgets characterizing these events. In this study, we seek to understand how post-fire sediment sources and erosional processes change over multiple storm cycles. Methods: In addition to hydrologic data described and provided here, sediment budgets in this project were derived from SfM/lidar data (see UNAVCO repository here for metadata/data: https://www.unavco.org/data/lidar-sfm/lidar-sfm.html). We installed two rain calibrated 0.2 mm tipping-bucket rain gages (Onset HOBO RG3-M), one located at a lower ridgeline (898 m elevation) and one located at the top of the watershed (1045 m elevation). The lower rain gage experienced a malfunction, but little difference in rainfall was found between gages for the storms with monitoring overlap, so we elected to use the continuous record of the upper-most gage. Soil volumetric water content sensors (Campbell Scientific CS616) were installed in depth profiles (5, 15, 30 cm) that were established on a north-facing shoulder slopes adjacent to the upper rain gage. In order to detect hillslope runoff production during storm events, we installed a ~ 50 cm diameter circular runoff plot following the design of Moody and Ebel (2012b) to identify storms that produced runoff near the upper drainage divide. We calculated 2-minute runoff values (Q2, mm hr-1) by dividing discharge (mm3/hr) from each bucket tip of a repurposed Onset HOBO RG3-M 0.2-mm tipping bucket rain gage by the bounded plot area (mm2). By converting to runoff values, we can facilitate the comparison of these values through a plot-scale runoff coefficient through the division of summed runoff by summed rainfall from the nearby tipping bucket gage. Finally, a Solinst Levelogger pressure transducer was installed further downslope in a hole drilled into bedrock channel (drainage area = 17 ha) to analyze the timing and peak pressure head (Hp) of sediment-laden flows as an integrated expression of watershed response (Kean et al., 2012). If significant rain was forecasted, the transducer was manually triggered to record at a 10-second frequency along with a barometric sensor (Solinst Barologger) tied to a tree adjacent to the channel in order to remove atmospheric pressure fluctuation from the pressure head time series.