Date of Award

Winter 2009

Project Type


Program or Major

Earth Science: Hydrology

Degree Name

Master of Science

First Advisor

Wilfred M Wollheim


Reach scale experiments have shown that transient storage (TS) could be an important control on dissolved inorganic nitrogen (DIN) export to coastal waters. Here, the relative roles the main channel (MC), surface TS (STS) and hyporheic TS (HTS) have in DIN removal at the network scale are investigated using a model applied to the Ipswich River in Massachusetts. Collaborative field investigations in 1st through 5th order reaches of the Ipswich River provided the mean and range for the hydraulic parameters controlling TS connectivity and residence time. DIN removal was simulated in the MC, STS and HTS compartments for every river grid cell using hydraulic characteristics, simulated discharge, and a constant reaction rate. Application of mean network parameters resulted in removal of 73.1% of total DIN inputs with the MC, HTS, and STS contributing 38.2%, 20.9%, and 14.0% respectively. Sensitivity analyses suggest large rivers and hotspots greatly impact DIN fluxes.