Water Temperature Variability in the West Branch of the Susquehanna River and Its Tributaries

Abstract

The water temperature and hydraulic characteristics of a river create environments that support complex habitats within the river and its tributaries. Measurements of water temperature are collected using a network of over fifty HOBO Pendant® data loggers placed in the West Branch of the Susquehanna River (WBSR) and its tributaries. Analyses of water temperature variations achieve several goals, including (1) mapping of the spatial variability in water temperature in the West Branch of the Susquehanna River, (2) identification of primary groundwater inflow sources to the WBSR, and (3) general characterization of hydraulic mixing where smaller tributaries enter the main river. A broadly-spaced network of water temperature data loggers in the WBSR is being used to better characterize general longitudinal and cross-channel temperature variability. Methods are developed for mapping of longitudinal transects of the WBSR from Muncy, PA to Winfield, PA using a SonTek RiverSurveyor® M9 system in combination with In-Situ and Solinst data loggers. In combination with geologic data and field observation, analyzing near- bed temperature, water-surface temperature, water conductivity levels, and general temperature mapping identifies potential groundwater inflow sources to the river. A detailed network with data loggers more closely spaced is installed at major tributary confluences with the main river to allow for the characterization of hydraulic mixing at these locations. Overall, this collection of water temperature variability and velocity data on the West Branch of the Susquehanna River and its tributaries serves as an initial step in understanding the hydraulic dynamics necessary for proper river and stream management decisions that consider the long-term sustainability of the river\u27s ecosystem processes