Stream Temperature Tolerance

This dataset represents a scaled version of the headwater stream temperature tolerance index based on a model developed by Dr. Ben Letcher and associates at the USGS Conte Anadromous Fish Lab, which is a measure of the relative sensitivity of stream temperatures to rising air temperatures. Specifically, sensitivity is measured by the slope of the linear relationship between air and stream temperatures during the spring season when air temperatures are rising. A steeper slope indicates that stream temperature responds faster to air temperature change, while a shallow slope indicates that stream temperature is more independent of air temperature change. Lower values (i.e., shallower slopes) are interpreted as being more tolerant under climate change, possibly because of groundwater influence or other factors. Conversely, streams with higher slopes are likely to be more impacted by increased air temperatures. In the layer provided here, the raw rising slope index is inverted and (quantile) scaled by HUC6 watershed so that the least tolerant headwater creek (steepest slope) gets a 0 and the most tolerant (shallowest slope) gets a 1 within each watershed.