Biogeochemical and sediment characteristics of streambanks with and without preferential groundwater discharge in the Farmington River Watershed, CT, USA

<p>We performed thermal infrared surveys to locate thermal anomilies, indicative of preferential groundwater discharge, along exposed streambanks in three stream reaches within the Farmington River watershed (northwestern CT and southwestern MA, USA). Our sites include 1) the River Island reach, a section of the 5^th order Farmington River, 2) West Branch Salmon Brook, a 3^rd order tributary to the Farmington River, and 3) Stratton Brook, a 2^nd order tributary to the Farmington River. Once areas of preferential groundwater discharge were located, we performed sediment-to-atmosphere greenhouse gas flux measurements and collected groundwater and sediment samples. In addition, we performed sediment-to-atmosphere greenhouse gas flux measurements and collected sediment samples from adjacent streambanks without preferential groundwater discharge. Surface water samples at each of the three stream reaches were also collected. Data collected include greenhouse gas fluxes (CO₂, CH₄, and N₂O), sediment organic matter, groundwater and surface water chemistry (CO₂, CH₄, and N₂O concentrations, dissolved organic carbon, dissolved oxygen, total dissolved nitrogen, specific conductance, NO₃^-_N), and groundwater and surface water temperature.</p>