Figure 1: Map of ER site and measurements of the SFA and some collaborators. The yellow line indicates the East River Community Observatory domain. The red lines indicate the major drainage boundaries of the East River, Washington Gulch (Wash. Gul.), Slate River, and Coal Creek. The blue lines show stream flow lines determined from the National Hydrography Dataset (U.S. Geological Survey, 2001). Measurements by community partners in the Slate River and Redwell basin are not shown. The white box shows the intensively sampled Pumphouse subregion, which include measurements along a hillslope transect and and the meandering floodplain of the East River.
East River Measurements, field and data management infrastructure
The SFA and collaborators have collected sample- and sensor-based measurements at several locations across the East River and adjacent drainages (Figure 1). Regions of particular emphasis include “SFA-intensive” sites located within representative meanders and a hillslope in a lower montane subregion (labeled ‘Pumphouse’) of the pristine East River drainage basin, where several cross-disciplinary, co-located measurements are being conducted. Additional “satellite” sites, targeting specific research questions are located near the Brush Creek confluence floodplain, an elevation gradient of research meadows along Washington Gulch and on the flanks of Cinnamon Mountain and Mount Baldy, Snodgrass Mountain, and mining-impacted sites in both Coal Creek and the Redwell Basin.
The ER instrumentation network maintained by the SFA and collaborators includes 15 stream-gaging and water quality stations used to obtain paired concentration-discharge measurements, 6 weather stations with soil moisture and temperature probes, 18 instrumented groundwater wells (e.g Figure 2a-2c), and about ~40 piezometers, ~15 ecohydrological sensor stations, and ~40 digital phenocam locations (Varadharajan et al. 2020). An eddy flux tower is maintained in the East River floodplain by the National Center for Atmospheric Research (NCAR). Extensive measurements of depth-resolved snow density, snow water equivalent, whole snowpit and rain chemistry, and stable isotopes of snow, rain and snowmelt water have been conducted over multiple years to inform stream water sources (Fang et al., 2019). Snowmelt manipulation experiments in vegetation plots in different mountain life zones were used to study the impacts of snowmelt timing on vegetation phenology. Metagenomic analyses of microbial communities have been conducted for soils and sediments representing various locations across the floodplain meanders and lower montane hillslopes that contribute water and solutes to the river (Lavy et al., 2020; Matheus Carnevali et al., 2020; Sorensen et al., 2020), resulting in over 5,000 metagenome-assembled genomes. In addition, several multi-institutional remote sensing campaigns have been conducted at the ER which include a 2015 Light Detection and Ranging (LiDAR) survey led by the SFA (Wainwright & Williams, 2017), Airborne Snow Observatory (ASO) flights by the National Aeronautics and Space Administration’s Joint Propulsion Laboratory (NASA JPL) in 2016, 2018 and 2019 (Painter et al., 2016), a 2017 USGS Airborne Electromagnetic survey, and a 2018 National Ecological Observation Network (NEON) hyperspectral survey paired with an extensive ground-based campaign conducted in coordination with Stanford University (Chadwick et al., 2020). In 2021, a two-year deployment of the DOE’s Atmospheric Radiation Measurement (ARM) Program mobile Surface Atmosphere Integrated Field Laboratory (SAIL) will use more than three dozen instruments to collect a suite of meteorology, clouds, aerosol and other atmospheric measurements in the ER (http://sail.lbl.gov). The SFA’s ER measurement locations are viewable through a public, user-friendly field information portal (https://wfsfa-data.lbl.gov/watershed/).