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Use of Multiscale Stressor Data in Stream Condition Analyses
Citation:
Leibowitz, S. AND L. Riato. Use of Multiscale Stressor Data in Stream Condition Analyses. Use of Multiscale Stressor Data in Stream Condition Analyses, Denver, CO, March 26, 2019.
Impact/Purpose:
EPA's Western Ecology Division has been working to develop a conceptual framework that relates stream condition to multiscale stressor data. Three axes represent three scales of stressors: the z-axis represents water-column scale stressors, the x-axis represents catchment-scale (local) stressors, and the y-axis represents watershed-scale (upstream cumulative) stressors. The color of the plotted data represent the biological condition of the stream. Besides distinguishing three different scales of stressors – possible allowing for distinct management actions – this also allows for analytical flexibility, e.g., watershed stressors could be represented by the IWI, a default dataset that is nationally available, or a more locally available state dataset. Similarly, biological condition could be represented by OST’s Biological Condition Gradient, one of the National Aquatic Resource Survey’s (NARS’) indicators, or a state indicator. This talk will be presented to EPA's Office of Water and EPA's Region 3 representatives, as well as possible collaborators from Virginia, West Virginia, New Jersey, Connecticut, and Washington to obtain input on how an upcoming study could be using for state and regional decision-making.
Description:
EPA's Western Ecology Division developed the Index of Watershed Integrity (IWI) and Index of Catchment Integrity (ICI) to map integrity throughout the conterminous US (CONUS) at two spatial scales: for all of the land contributing to single stream segments, including upstream flows (watersheds), and for just the land contributing directly to stream segments, and excluding upstream flows (catchments). These maps were developed using the StreamCat dataset, which has also been applied to interpolating sampled data from the National Rivers and Streams Assessments to unsampled streams. Since the IWI and ICI map integrity based on stressor distributions, the two indices are being used as a generalized stressor gradient in the Puget Lowland/Willamette Valley (PLWV) Biological Condition Gradient (BCG) assessment. Here we present a conceptual framework that generalizes that work. Three axes represent three scales of stressors: the z-axis represents water-column scale stressors, the x-axis represents catchment-scale (local) stressors, and the y-axis represents watershed-scale (upstream cumulative) stressors. The color of the plotted data represent the biological condition of the stream. Besides distinguishing three different scales of stressors – possible allowing for distinct management actions – this also allows for analytical flexibility, e.g., watershed stressors could be represented by the IWI, a default dataset that is nationally available, or a more locally available state dataset.