Predicting thermally stressful events in rivers with a strategy to evaluate management alternatives

River Research and Applications
By: , and 

Links

Abstract

Water temperature is an important factor in river ecology. Numerous models have been developed to predict river temperature. However, many were not designed to predict thermally stressful periods. Because such events are rare, traditionally applied analyses are inappropriate. Here, we developed two logistic regression models to predict thermally stressful events in the Delaware River at the US Geological Survey gage near Lordville, New York. One model predicted the probability of an event >20.0 °C, and a second predicted an event >22.2 °C. Both models were strong (independent test data sensitivity 0.94 and 1.00, specificity 0.96 and 0.96) predicting 63 of 67 events in the >20.0 °C model and all 15 events in the >22.2 °C model. Both showed negative relationships with released volume from the upstream Cannonsville Reservoir and positive relationships with difference between air temperature and previous day's water temperature at Lordville. We further predicted how increasing release volumes from Cannonsville Reservoir affected the probabilities of correctly predicted events. For the >20.0 °C model, an increase of 0.5 to a proportionally adjusted release (that accounts for other sources) resulted in 35.9% of events in the training data falling below cutoffs; increasing this adjustment by 1.0 resulted in 81.7% falling below cutoffs. For the >22.2 °C these adjustments resulted in 71.1% and 100.0% of events falling below cutoffs. Results from these analyses can help managers make informed decisions on alternative release scenarios.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Predicting thermally stressful events in rivers with a strategy to evaluate management alternatives
Series title River Research and Applications
DOI 10.1002/rra.2998
Issue 32
Year Published 2016
Language English
Publisher John Wiley & Sons, Ltd.
Contributing office(s) Coop Res Unit Leetown
Description 9 p.
First page 1428
Last page 1437
Country United States
State New York
Other Geospatial Delaware River