Institute of Ecosystem Studies

2008 BES Annual Meeting Presentation and Poster Abstracts

Lessons Learned from the Baltimore WATERS Test Bed
Runyan, Christiane
Co-Authors: Christiane Runyan, Philip Larson, Claire Welty, Jon Dillow, Ed Doheny, Jeff Kvech, Andy Miller
Abstract: The goal of this project is to establish an observing system of all components of the hydrologic cycle at sites throughout the Baltimore metropolitan area, using the Gwynns Falls watershed as a pilot study. This project builds on the extensive BES backbone of hydrologic measurement equipment already in place. Efforts to date include: (1) connecting existing BES stream gages to the USGS real-time network and adding nine real-time stations to the network; (2) replacement of BES raingages with real-time dual tipping bucket gages; (3) “adoption” of seven homeowner wells and outfitting with automatic water level recorders; and (4) hand-augering of eight riparian zone piezometers and outfitting with automatic water level recorders (capacitive probes). Our lessons learned to date include: • Obtaining accurate discharge measurements in urban streams requires discretion with site selection, immediate discharge measurement following storm events, use of USGS streamflow measurement protocol, and technological advancements such as use of the acoustic doppler velocimeter. • Real-time, research-grade tipping bucket rain gages deployed in tandem provide a high quality continuous data record that (1) increases precision of the precipitation record and (2) enables rapid response for troubleshooting malfunctioning gages. • Water level data obtained from a capacitive sensor can differ by up to 280mm from the measured water level and this error can change by 50mm over one month. The effects of groundwater conductivity, biofilm on the sensing dielectric, daily fluctuation of groundwater temperature and calibration methods are being explored to determine their role in these errors.