Continuous measurements, every 15-30 minutes, were made of stage, water temperature, conductivity in Cart Creek, Newbury, MA, a small headwater stream draining a mainly forested catchment (55% forest + 19% wetland). Discharge is determined from stage using discharge vs stage regressions. Several day gaps occur periodically due to removal for recalibration.
YSI information is available from only a small portion of the year. This year, we shifted to using HOBO data loggers for our depth measurements. These can be deployed during the winter period. As a result, for most of the year, depth is based on measurements using a HOBO depth data logger. A borrowed HOBO was temporarily deployed between Jan and Mar 2006 in a temporary location. A new HOBO was permanently deployed in a stilling well in July 2006. Depth measurements by the HOBO deployed in the stilling well are considered reliable. YSI: YSI 6200 data sondes were deployed vertically in a pool deep enough to contain water during dry conditions. The sonde was deployed in a PVC tube, which was attached to ree-bar driven into the stream bed. The PVC tube had holes drilled to allow adequate water circulation. The PVC tube was surveyed upon original deployment in 2001 and resurveyed in 2002 to ensure that elevation did not change during winter ice period. No change was detected. No evidence of change has been noted through 2006 based on discharge measurements. See discussion below for development of the discharge-stage relationship. Recalibration of conducitivty and depth was performed roughly every 4-6 weeks. Instrument drift during deployment periods was not significant. HOBO: Depth and water temperature are recorded by the HOBO data logger. Depths are corrected for barometric pressure changes using readings in an additional HOBO datalogger deployed at Marshview Farm. Between Jan and March 2006, a borrowed data logger was deployed attached to a cinder block placed on the stream bottom. A newly purchased HOBO data logger was deployed in a permanent stilling well in July 2006. The HOBO is deployed in a a PVC tube, which was attached to ree-bar driven into the stream bed. The PVC tube has holes drilled to allow adequate water circulation. The hobo of Jan-Mar 2006 was standardized to the permanet HOBO using: Jan-Mar 2006: YSI_Depth = TEMP_HOBO_DEPTH + 0.0822. HOBO_Depth = YSI_Depth + 0.17549 ADDITIONAL RESEARCH LOCATION COORDINATES: In addition to the decimal degree coordinates given above, locations are also given here in Massachusetts State Plane coordinates. The stream is called Cart Cr. and is located in Newbury MA. Some residential area is present. (~ 10% of the basin). In addition, I-95 passes through the center of the catchment, resulting in roughly 8% impervious surface area STATION STATE X STATE Y YSI-CC 247680 946790 NOTES AND COMMENTS: Velocity measurements were made using a Marsh McBirney current meter. Discharge estimates in Cart Cr. are based on a power rating curve that contains measurements up to a depth of 0.8 meters, as standardized to depth measured with a HOBO datalogger (Column = HOBO_Depth), which is above bankfull stage. Rating curve has been standardized to HOBO_Depth to allow application of a single rating curve across years. Rating curve has an R2 of 0.96 using 32 measurements between 2001 and 2007. All files in this series (2001-2006) are currently standardized to HOBO_depth. The column Depth_Device is included when combining files from several years, over which several different devices were used to calculate depth. HOBO_Depth is the depth that is standardized across all measurement devices so that a single rating curve can be applied. CALCULATIONS: Discharge rating curve : Discharge (l/s) = 731.91 (depth) ^ 5.5172 where depth is HOBO_Depth
Periodic with improvement of rating curve, particularly as more high discharge events are incorporated. This file was initially posted in September 2007. Version 01, 30 Oct 2007 updated metadata to EML level 3+ Version 02, 21Jan2010 keyword update Version 03, 15May2013, metadata and data updated to comply with importation to Drupal and LTER PASTA. Used MarcrosExportEML_HTML (working)pie_excel2007.xlsm 3/14/13 12:02 PM for QA/QC to EML 2.1.0