CICEET Progress Report for the period 9/01/01 through 3/01/02

Project Title: Accessible Methodology for Monitoring Estuarine and Coastal Vegetation Cover
Principal Investigator(s): Charles C. Sarabun, Daniel G. Ondercin, Linda Frizzell-Makowski, William S.L. Banks, Jonathan J.A. Dillow

Accomplishments
Scheduled Tasks:

1. Resurvey Otter Point Creek.
2. Re-survey at known groundwater inflow site (Herring Creek).
3. Survey Blackbird Creek NERR site.
4. Participate in Chincoteague Bay survey with USGS, NPS and Maryland DNR.
5. Document results of the surveys. Document and provide copies of the DAQ software and analysis software to CICEET. Document the details of the system assembly and components and provide to CICEET.

Unscheduled Tasks
Results of the project were presented in a paper given at the Geological Society of America Annual Meeting, Boston, MA, 5 November 2001 in the special session entitled Groundwater Discharge to Estuaries. In addition, results from the Herring Creek survey were made available to an interested citizens group.

Progress on Tasks

1. Otter Point Creek (OPC) was resurveyed on 12 September. Figure 1, Otter Point Creek chart showing selected tracks and location of 2 events, shows three survey tracks from 12 September and the locations along the track of two groundwater events. Figure 2, Time series of the thermistor array (top) and pH (bottom) for event 1, shows the time series of the thermistor array and the pH sensor. Note the sudden decrease in temperature of the bottom thermistor. This is consistent with the ground truth signature seen in Herring Creek (previous Progress report). The cold water is only seen by the lowest thermistor and not by the next thermistor up which is at the level of the manifold intake. Therefore, there is no pH signature. Note that this location is proximal to a suggestion of an event seen in the initial OPC survey in 2000 (previous progress reports).

   Figure 3, time series of thermistor array (top) and depth (bottom) for event2, shows the time series from event 2. This event was located where seepage from the base of a bluff could be visually seen to enter OPC as shown in Figure 4, Otter Point Creek where the time series of Figure 3 was obtained. Note the inflow in the center of the picture. This inflow originated at the base of the bluff to the left of the storage shed. In this case there was no pH signature calling into question whether or not this event could be classified as groundwater despite the fact that there is no vertical temperature structure before or after the event. Later in the time series everything becomes colder but this is due to sinking into deeper water as evidenced by the pressure record shown in the bottom panel of Figure 3.

2. On 29 August we attempted to resurvey Herring Creek at the site of the previously seen inflow (see previous progress report). However, there were relatively high winds blowing onto the shore at that site and the water column was well mixed. However, the opposing shore was sheltered in the lee of high bluffs and heavy stands of trees so we decided to survey that area. Figure 5, chart of Herring Creek showing ground tracks and locations of three events, shows the survey tracks and the locations of three events seen in the data. Figure 6, time series of the thermistor array (top) and pH (middle) and depth (bottom) for event 1, shows a time series from the thermistor array, pH and depth sensors. At relative time 200 seconds, we see a distinct vertical gradient in the thermistor array and a corresponding decrease in pH in the second panel. What is initially confusing is that this appears to be a warm water event. The discrepancy might be explained by the depth record in the bottom panel where we are clearly seen to be entering shallower water and warmer water overall. Figure 7, time series of the thermistor array (top) and pH (middle) and depth (bottom) for event 1, shows events 2 and 3. These events are much less clear. Both show the clear vertical stratification as measured by the thermistor array, but the pH signature is ambiguous (event 2) or absent (event 3).

   On 22 August we attempted to survey a second NERR site, Blackbird Creek in central Delaware. Unfortunately, there were many dead trees in the water making a safe survey difficult. In addition there were several difficulties with equipment. As a result, we were unsuccessful at Blackbird Creek. We did not return due to the lack of remaining funds. Note: we had sufficient funds for one remaining survey and it was decided to resurvey OPC where we had seen suggestions of inflows in previous data but had been prevented from successful resurveys due to wind mixing on several occasions.

3. This survey did not take place as the NPS/USGS/MD-DNR coalition survey did not take place.

4. The data acquisition program and data analysis programs have been documented. The system assembly and use documentation is in preparation.

Difficulties Encountered

1. No difficulties were encountered at OPC.

2. As indicated above, wind stirring homogenized the water column at the previous Herring Creek site. However, no difficulties were encountered in surveying a second, wind-protected Herring Creek site.

3. The major difficulties encountered at Blackbird Creek were: 1) many submerged obstacles making contiguous surveying difficult and 2) problems with both hardware and software. We were still using a jury-rigged DAQ hardware system while waiting for replacements for previously stolen hardware. The interim system used a number of interconnected USB ports, with which our version of Windows NT had periodic problems. In addition, there were also problems with the manifold pump resulting in intermittent operation.

4. No major difficulties.

Anticipated Success in Meeting Project Objectives in Scheduled Project Period
Our success at a second Herring Creek site and the Otter Point Creek site gives us confidence that we can detect groundwater inflows. However, it is clear that the survey tracks must be carefully planned since stirring caused by the sled appears to erase the immediate signature and may require some time before sufficient groundwater seeps back to form a detectable signature. In addition, it is clear that the surveys must be conducted at slack water on days were wind stirring is not occurring.

Preliminary Results
Preliminary data have been shown in figures 1-6..

Tasks and activities for next reporting period

Tasks for the next reporting period
a. Complete the system documentation.

Work plan to accomplish tasks
a. The only remaining piece of documentation is the report detailing how the system was assemble and used along with documentation of results. This report is approximately 50% completed. Completion was delayed to give our accounting section time to determine exactly how much of the funding remained to complete this task.

Concerns or difficulties
None.

Expenditures
Report submitted separately by JHU/APL accounting. Project expenditures were within the range anticipated.