Acceptance and utilization of PIE-LTER data requires that:
· The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions.
· The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications.
· A copy of any resultant publications should be sent to:
(Principal Investigator)
Ecosystems Center;
Marine Biological Laboratory
Woods Hole, MA 02543
PLUM ISLAND ECOSYSTEM LTER DATABASE
DATA FILE: WAT-YSI_UpperIps_2001.txt
DOCUMENTATION FILE: WAT-YSI_UpperIps_2001.doc
YEAR: 2001
PI: Charles Vorosmarty
OTHERS: Wilfred Wollheim, Brian Pellerin
BRIEF DESCRIPTION OF DATA FILE: Continuous measurements, every 15 minutes, were made of stage, water temperature, conductivity, dissolved oxygen, and pH in a small headwater stream draining a moderate sized, mixed land use watershed. Measurements are for part of the ice free season (June – December). Discharge is determined from stage using discharge vs stage regressions. Several day gaps occur periodically due to removal for recalibration.
KEYWORDS: discharge, water temperature, conductivity, pH, dissolved oxygen.
SITE TYPE: Watershed draining to Upper Ipswich
RESEARCH LOCATION: Locations are in Massachusetts State Plane coordinates. The site is located on the Ipswich R. mainstem at North Reading, just upstream of Rt. 28 (~48 km2 drainage area). The contributing area includes a large component of urban land use, but with significant wetland area remaining, especially in floodplain. Large amounts of water withdrawals occur upstream.
STATION STATE X STATE Y
YSI-IR 232080 923630
EXPERIMENTAL DESIGN AND METHODS:
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. Dissolved oxygen measurements are of good
quality because detritus did not accumulate in the bottom of the pool (unlike
our suburban site). 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. See
discussion below for development of the discharge-stage relationship. Recalibration was performed roughly every
4-6 weeks. Instrument drift during
deployment periods was not significant.
NOTES AND COMMENTS:
Discharge measurements in the Ipswich R. at North Reading are based on a linear rating curve that contains measurements up to a depth of 0.8m. Flows above this amount are estimated using a linear extrapolation. Thus flows determined from levels greater than 0.475m are approximate (4 % of the readings in 2001 deployment period).Rating curve had an R2 = 0.99. Measurements are based on 8 measurements taken in 2001.
Dissolved oxygen concentrations reflect water column levels.
NA refers to data not available.
VARIABLE DESCRIPTION:
Date = date (yyyy-mm-dd)
Time = time (hh:mm:ss)
Temp = water temperature (oC)
SpCond = specific conductivity (mS/cm)
DO% = dissolved oxygen percent of saturation (%)
DOConc = dissolved oxygen concentration (mg/l)
Depth = stage height (m)
pH = log of the H+ ion concentration
Flow = discharge (l/s)
CALCULATIONS:
Ipswich rating curve in 2001 :
Discharge (l/s) = 703.55 (depth) – 46.79
FOR MORE INFORMATION, CONTACT:
Wil Wollheim
OTHER DATA FILES TO REFERENCE:
All in the YSI series.
REFERENCE CITATIONS:
DATA AVAILABILITY STATUS:
Type 2
ARCHIVE INFORMATION:
Date of entry: Jan 21, 2004
Data entered by: W. Wollheim
Comments: