Source: UNIVERSITY OF MAINE submitted to
THE ROLE OF GROUNDWATER ON MAINEÿ¿ÿ¿ÿ¿ÿ¢ÿ¿ÿ¿ÿ¿ÿ¿ÿ¿ÿ¿ÿ¿ÿ¿S WETLAND SYSTEMS.
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
1010030
Grant No.
(N/A)
Project No.
ME021711
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2016
Project End Date
Sep 30, 2021
Grant Year
(N/A)
Project Director
Reeve, A.
Recipient Organization
UNIVERSITY OF MAINE
(N/A)
ORONO,ME 04469
Performing Department
School of Earth and Climate Sciences
Non Technical Summary
Wetlands are the expression of their hydrologic setting. This hydrologic expression can be easily observed in many wetland systems, such as tidal marshes and riparian (stream-side) swamps. Some wetlands, however, are strongly impacted by the subsurface hydrology or intermittent overland flow that is not as easily observed. In this project, the role of groundwater flow in two Maine wetland systems, peatlands and vernal pools, will be investigated to assess the importance of groundwater flow or processes associated with groundwater flow in these systems.In vernal pool systems, this investigation will focus on quantifying the importance of groundwater flow on the overall water budget of these systems and how this groundwater flow connects vernal pools to the surrounding landscape. This work will provide information useful to vernal pool conservation efforts by determining how changes in land-use near a vernal pool and climate change will impact a vernal pool's hydrology and the organisms that rely on these wetland systems. The degree of hydrologic isolation of wetlands has important regulatory implications for the protection of vernal pools and this work will provide information on their hydrologic isolation at several locations in Maine. Planned work in veranl pools includes measuring vertical groundwater flow rates in six (or more) vernal pools in central Maine using traditional well measurements (measuring vertical hydraulic head gradients), measuring temperature in sediments lining the pool basin and estimating vertical flow rates using heat transport computer models, snow pack measurements, and using idealized groundwater flow models based on this data to assess how vernal pools interact with regional groundwater flow systems.Some peatlands are also isolated from obvious surface runoff. In these systems, the subsurface hydrology interacts with the vegetation growth to create an environment favorable for the steady accumulations dead plant material (peat) over thousands of years. The thick deposits of water saturated peat create an environment the both serves as a major sink for carbon dioxide while also emitting carbon dioxide and methane, both 'greenhouse gasses', to the atmosphere. Much of the current research on peatland systems focuses on how these systems influence the concentration of these greenhouse gasses in the atmosphere and their role in climate change. Two aspect of this carbon cycling process will be investigated in this project: (1) monitoring rapid changes in groundwater levels in a well to identify the location and timing of bubble production and movement in the peat column to provide insight into where in the peat column carbon gasses are produced and released to the atmosphere, and (2) measuring groundwater flow directions to understand how solutes (nutrients and substrate used by gas-producing microbes) move within the peat deposit. This work will include monitoring water levels at minute intervals in wells open at different depths to monitor for anomalous rapid changes in water level hypothesized to be related to bubble movement within the peat column. Computer models that simulate the flow and transport of solutes will be coupled to weather data and biogenic gas production to assess carbon cycling within peatland systems.
Animal Health Component
0%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020330205060%
1350330205010%
1020210205030%
Goals / Objectives
This project will investigate the role of groundwater hydrology in wetland systems to improve understanding of [1] how wetland systems are integrated into regional groundwater systems and the broader landscape, [2] how groundwater hydrology influences solute transport processes within wetland systems, and [3] how groundwater measurements and computer modeling can be used to better understand carbon dynamics within peat forming wetland systems.Specific objectives include:Monitor hydraulic head in wetlands to determine vertical groundwater flow directions and to calculate rates of groundwater recharge or discharge.Monitor temperatures in wetland sediments to capture the diurnal temperature signal and vertical temperature gradients and use these data to estimate groundwater flow velocity and direction from these data.Evaluate water-level time series data collected in wetlands to identify diurnal trends associated with evapotranspiration, trends associated with groundwater flux, and to identify anomalies related to gas movement within the sediment column.Construct computer models that incorporate groundwater to integrate collected data and aid in interpreting the role and importance of groundwater in wetland and surface-water systems.
Project Methods
Work on this project will focus on [1] a suite of vernal pools located in Bangor and Osborn, Maine and [2] a 2200 hectare peatland systems (Caribou Bog) located between between Orono and Bangor, Maine. The six vernal pools selected for study span a range of conditions that will allow a comparison of pool hydrology based on surrounding land use and surficial geologic conditions. Reeve and his collaborators have collected an impressive data set over the past decade from Caribou Bog to assess groundwater hydrology and carbon cycling within this system. Work associated with this proposal will build on past work in these systems to address current questions related to peatland hydrology.VERNAL POOLSGroundwater exchange with vernal pools will be assessed by comparing water levels in the surface water and a monitoring well previously installed in each vernal pool. These monitoring wells where installed in a core hole created using a gauge auger. A PVC pipe (2.5 cm diameter flush threaded PVC with 30 cm long machine slotted screen) was then driven into this hole. The well was surged and pumped out to remove sediment from the screen and bottom of the well. Water levels in and surface water adjacent to wells will be measured during site visits using a blow tube, a plastic tube fitted with a tape measure. Water levels are detected by blowing into the tube, lowering the tube until bubbling is detected, and then recording the depth of the tube from the top of the well. Traditional electrical water level meters are difficult to use in the low specific conductance waters found in some vernal pools. Water levels inside the monitoring wells and in stilling wells fixed to monitoring well will also be monitored using a non-vented data logging pressure sensor set to record data at 15 minute intervals. These continuously collected pressure data will be corrected for atmospheric pressure using a barometric pressure sensors and resulting water levels will be compared with manual measurements to verify the data loggers are providing accurate water level measurements.Piezometer tests will be completed in each of the wells by displacing water in the well and measuring water level recovery over time. Hydraulic conductivity of the sediments will estimated from this data using the Hvorslev method (Hvorslev, 1951). The specific discharge of groundwater into or out of the vernal pool will be calculated using Darcy's Law from the measured hydraulic gradients and hydraulic conductivities.Vertical groundwater flow rates will also be estimated using temperature data collected across the upper 30 cm of the pool bed (Lautz, 2010; Silliman et al., 1995). A one-dimensional heat transport models (Anderson, 2005; Vandenbohede and Lebbe, 2010), previously prepared by Reeve, will be calibrated to temperature data collected across the pool bed by adjusting groundwater flow velocity and porosity within the computer model. These computer models will be compared to analytic solutions (Swanson and Cardenas, 2011; Stallman, 1965) to verify that the computer model is producing reasonable results.PEATLANDSNine monitoring well clusters have been established in Caribou Bog, each composed of six to eight 2.5 cm diameter wells that are screened at different depths within each well cluster (Bon et al., 2014). To reduce movement of the wells in the soft peat, wells have been bolted together in a wooden frame, using the wells driven to the mineral sediments beneath the peat to stabilize shallow wells. Well depths range from 0.5 m below the peat surface to the peat interface with mineral sediments (depths of up to 10 m). All wells were developed by surging water through the well screens and pumping debris from the wells using a hand vacuum pump. Wooden catwalks were placed by each well to prevent excessive compaction and distribute the weight of individuals monitoring the wells. To expand out monitoring network, two additional well clusters will be installed, using the same procedures, in the peatland lagg and near the interface between the bog and fen landforms in Caribou Bog. Current wells are located in the bog portion of this peatland, and these additional wells will expand our measurements into the fen, allowing a comparison of processes across peat landforms. Each well cluster will be surveyed using a pair of dual frequency GPS system and these data will be processed using on-line post-processing services (Silver, 2013).Non-vented data-logging pressure sensors, with enough memory to record water level data at 8minute (or higher frequency) intervals for at least 6 months, will be deployed in all wells in three well clusters (those previously monitored), and two wells in five of the remaining well clusters. Two barometric pressures sensors, for data redundancy, will be placed at central locations within Caribou Bog to compensate water pressure data for atmospheric pressure changes. Time series data will be analyzed both by visually inspecting plots of hydraulic head vs. time and by using Finite Impulse Response filters to identify high frequency anomalies within the data (Strum and Kirk,1988). Preliminary work by Reeve on previously collected data sets indicate this method identifies most high frequency anomalies recorded with the data loggers.Computer models that incorporate groundwater hydrology will be used to integrate the date collected in these different systems and to aid in the interpretation of hydrologic processes. These models will include:idealized groundwater flow (Reeve et al., 2006) and transport models (Reeve et al., 2001) developed using MODFLOW and its family of software tools (Harbaugh, 2005) to create simulations integrating hydrologic data collected at vernal pools with other available geospatial data sets to assess the interconnection between recharge or discharge at vernal pools with regional groundwater flow systems,the creation of one-dimensional models, using a scripting language, to assess vertical groundwater flow within peatland systems and its potential role in transporting solutes into the deep peat that could sustain methanogenesis (similar in spirit to models created by Reeve et al. (2013) to assess vertical movement of peat),and the creation of box models to explore vernal pool water budgets and carbon cycling processes with peatlands (Zhang et al., 2012). Simulation results will be interpreted with the aid of visualization software that allows the creation of sophisticated graphics including 3-D images and animations. Because many of the parameters used in our computer models will be poorly constrained, sensitivity analysis will be performed to identify how changing model parameters will influence groundwater flow patterns, hydraulic heads, and chemical flux rates within models. Because there is limited readily available hydraulic head data outside of the relatively small study areas, model calibration will be limited to matching data to our own monitoring wells, and limited data that can be obtained from nearby wells using the parameter estimation software such as PEST (Doherty, 1994). The intent will be to explore broader patterns using realistic, but idealized, models; not to produce models that are accurate depictions of site specific conditions.

Progress 10/01/16 to 09/30/21

Outputs
Target Audience:Work on this project over the past year has targeted federal and state resource managers (e.g. Maine Inland Fisheries and Wildlife), environmental scientists, and rural water municipalities. I continue to work with a forestry management company and have been given permission to pursue groundwater monitoring work on peatland systems within their landholdings in Washington County, Maine. Results from statistical modeling, used to predict the location of groundwater dependent ecosystems, were presented at local and regional conferences with audiences composed of academic and government workers. I continue to work with the Old Town Water District (OTWD) to monitor groundwater interaction with the Stillwater River (Old Town, Maine). These efforts occur in conjunction with teaching activities that utilize OTWD monitoring wells to provide field experience to a hydrogeology class. Changes/Problems:The ongoing COVID19 pandemic impacted plans for out-of-state travel associated with field work and participation in conferences. What opportunities for training and professional development has the project provided?A groundwater modeling class was delivered to one graduate student who plans on using this tool for research activities related to groundwater dependent ecosystems. A class on data analysis using a scripting language was given to a mix of undergraduate and graduate students. An Environmental Geology course was delivered to about 100 undergraduate students. How have the results been disseminated to communities of interest?Results from this project have been provided through conference presentations and technical journal publications. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Outcomes for this reporting period focus on groundwater dependent ecosystems (GDE). This focus incorporates the use of geospatial statistical models that utilize available geospatial datasets (e.g. topography, geology, and vegetation distribution), coupled with known GDE presence data, to predict the presence of GDEs across a landscape at the pixel scale. Maximum Entropy (MaxEnt), a method typically used to predict species distribution, is used to predict to location of GREs. MaxEnt models have been created for different EPA ecoregions in the northeastern USA with an emphasis on ecoregions that occur in Maine. Field validation of Maximum Entropy modeling results within EPA's Mixed Woods ecoregion suggest that 87% of the model predictions are accurate. Data collected through field visits was supplemented with Maine Department of Inland Fisheries and Wildlife native Brook Trout surveys. Brook Trout, because they seek out cold water refugia, act as an indicator species in warm summer months for stream reaches receiving groundwater discharge. Maximum Entropy modeling across Maine's Atlantic Highlands and Mixed Woods Plains EPA ecoregions predict approximately 600 km (about 1%) of the mapped reaches in Maine have a 70% probability of conditions suitable for groundwater discharge. Groundwater discharge to streams was predicted for nearly a third of the 1409 locations where Brook Trout were identified. Project objectives are paraphrased below and associated activities are listed below each objective. 1. Monitor hydraulic head in wetlands. - Installed monitoring wells in groundwater dependent ecosystems at National Wildlife Refuges in Maine. - Deployed data loggers, downloaded data loggers, and manually measured water levels in monitoring wells at the Old Town Water District, in Caribou Bog, and at three of Maine's National Wildlife Refuges. - Performed field reconnaissance in peatlands located in Washington County, Maine. 2. Monitor temperatures in wetland. - Improved on method for deploying thermochron ibutton data logging temperature sensors to reduce water damage to these devices - Plotted and interpreted temperature and water level data logger data collected in monitoring wells. 3. Construct computer models to integrate collected data. - A graduate student validated the presence or absence of groundwater dependent ecosystems through site visits - Provided instruction on groundwater flow modeling software (MODFLOW) to a graduate student. - Assembled date into GIS software needed for the construction of a groundwater flow model and developed preliminary groundwater flow models to assess the role of geology on peatland hydrology. - Used the Maximum Entropy statistical method to model landscape suitability for groundwater dependent ecosystems based on landscape characteristics (e.g. slope, wetness index, geology). Other activities related to this work that do not fall under the specific project objectives include: - Re-submitted an application and work plan for a Fulbright Scholarship. - Assisted with the development and submission of a research proposal to the National Science Foundation. - Discussed groundwater-related erosion issues at the Tidal Falls Preserve (Hancock County, ME) with the Land Protection Manager for the Frenchman Bay Conservancy - Contacted the Maine Rural Water Association and began discussion about assisting with training activities - Was interviewed by a local high school teacher in support of classroom activities - Provided advising to undergraduate students in the Ecology and Environmental Science Program at the University of Maine - Modified materials for an Environmental Geology class to accommodate a student's accessibility needs - Participated in weekly graduate student advisory meetings

Publications

  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Glaser, Paul. H., Joshua Rhoades and Andrew S. Reeve (2021). The hydraulic conductivity of peat with respect to scaling, botanical composition, and greenhouse gas transport: Mini-aquifer tests from the Red Lake Peatland, Minnesota. Journal of Hydrology. 596:125686.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Janecky, D., P.H. Glaser, D.I. Siegel, J.P. Chanton, A.S. Reeve, D. Rosenberry, E. Romanowicz, L. Chasar, L.E. Corbett (2021). Large Peat Basins as Incubators of Methane and Carbon Dioxide: A Geochemical Perspective. Annual Meeting of the Geological Society of America. Portland OR, Oct 1-13. 10.1130/abs/2021AM-368738
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Snyder, S., C.S. Loftin, A.S. Reeve (2021). Using Landscape Variables as Surrogates to Predict Groundwater Influence in Stream Ecosystems: Maine, USA. 151st Annual Meeting of the American Fisheries Society. Baltimore, MD. Nov 6
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Snyder, S., C.S. Loftin, A.S. Reeve (2020). Mapping Groundwater Dependent Ecosystems in the Northeastern U.S. with the Maximum Entropy Algorithm (MaxENT). Presentation at the 2020 Annual meeting of The Wildlife Society. Delivered remotely. Sep 28 - Oct 2.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Snyder, S., C.S. Loftin, A.S. Reeve (2021). Predicting Probability of Groundwater Discharge to Freshwater Ecosystems with Landscape Variables in Maine, USA. Maine Chapter of the Wildlife Society. Orono, ME, Nov 1 - 5.


Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Results were presented to professional scientists through a publication in Geology. While abstracts for presentations targeting local audiences were accepted (e.g Maine Sustainability and Water Conference), delivery of those presentations where delayed or canceled due to the COVID-19 pandemic. A thesis defense presentation was given related to using groundwater modeling to manage water resources in Colombia. I provided assistance to LEA (not-for-profit organization) with downloading data from data logging devices and have discussed characterizing peatland systems owned by a forestry management company interested in the carbon sequestration potential of these wetland systems. Changes/Problems:As with everyone else, I faced new challenges related to the COVID19 pandemic. This challenges included complicated field activities, the departure of an undergraduate before she was able to finish laboratory work, and a signifiacnt increase in the time required to develop and deliver content for the classes I am responisble for, at the expense of research activities. What opportunities for training and professional development has the project provided?One new Ph.D. graduate student (co-advised) has begun a project related to groundwater dependent ecosystem identification with a focus on national wildlife refuge lands. This student has been provided training in basic groundwater hydrology, monitoring well installation, and groundwater monitoring methods. An undergraduate was provided with training in the creation and use of permeameters for measuring hydraulic conductivity, basic tool and laboratory methods, using a groundwater flow model to assess permeameter data, and using data logging pressure transducers for water level monitoring. A graduate student was provided with training in the use of MODFLOW, a widely used groundwater flow model, for the creation of idealized models to assess groundwater pumping. How have the results been disseminated to communities of interest?Results have been distributed through a journal publication, a thesis publication, and through conference abstracts. Information has also been distributed to the public through phone discussions and personal interaction with companies and reporters. I provided information on groundwater issues to a reporter from the Bangor Daily News related to a planned aquaculture facility (article published in July, 2020). What do you plan to do during the next reporting period to accomplish the goals?I plan on pursuing several related paths, and will follow the path that appears most likely to result in the best outcomes. These paths include: Continue with the peatland hydrology work, expanding it from Caribou Bog to other locations in Maine by working with a forestry management company interested in peatland resources on their landholdings. Continuing work on groundwater-dependent ecosystems by: providing additional hydrogeology and computer modeling training for a graduate student, assisting with the installation of additional shallow monitoring wells, collecting and interpreting water level data, and creating simple regional groundwater flow models for these study areas. Pursue environmental education activities to improve undergraduate STEM education including incorporating place-based activities within classroom activities. Working with previously collected data-sets to interpret and publish these results from past projects.

Impacts
What was accomplished under these goals? An undergraduate student worked toward measuring the hydraulic conductivity of peat cores collected using a Russian peat sampler. This work focused on developing the methodology to measure the permeability of a half cylinder cores of peat. These methods will continue to be refined as I work toward the detailed measurement of the permeability of peat deposits. Water level monitoring continued in Caribou Bog through the spring, 2020. Data loggers and other equipment were removed from Caribou Bog in the summer, 2020 as an NSF project ended. Time series analysis is being applied to these data to identify anomalies related to carbon gas ebullition. I assisted a graduate student with the development of a groundwater flow model for an arid region in Colombia. Knowledge developed from this work will be applied to planned groundwater modeling work in groundwater dependent ecosystems. I assisted a graduate student with the installation and monitoring of shallow groundwater monitoring wells in Sunkhaze Meadows, Rachel Carson and Moosehorn National Wildlife Refuges. Groundwater monitoring is ongoing at these sites. A rapid assessment methods to identify groundwater dependent ecosystems, developed by the U.S. Fish and Wildlife Service, was modified for use in the Northeastern USA.

Publications

  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Chen, X., X. Comas, A. S. Reeve, A. and L. D. Slater. 2020. Evidence for glacial geological controls on the hydrology of Maine (USA) peatlands. Geology. 48:771776.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Snyder, Shawn, C.S. Loftin and A.S. Reeve. 2020. Mapping Groundwater Dependent Ecosystems in the Northeastern U.S. with the Maximum Entropy Algorithm (MaxENT). AWRA Virtual Geospatial Water Technology Conference: Complex Systems, Aug 4-13, 2020.
  • Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: G�mez Ar�valo, Efr�n David. 2020. A Groundwater Flow Model to Aid in Water Resource Management for the Carraipia Basin in the Coastal Semi-Arid Region of La Guajira State (Colombia). M.S. Thesis Thesis in Earth and Climate Sciences, University of Maine, Orono, Maine.


Progress 10/01/18 to 09/30/19

Outputs
Target Audience:Work related to this project was presented to the general public during Orono Bog Nature Walk lead by Reeve. This presentation was delivered to a small group (about 10 people) and focused on the role of hydrology in peatlands and how hydrology influences and is influenced by the carbon cycling ( e.g. carbon-based greenhouse gas release and sequestration). Research results were presented to geoscientists and environmental professionals at two scientific conferences. Data, project photographs and results were presented to students at the University of Maine. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One undergraduate student (Grace Mullens) has been incorporated into this work. She has: assisted with manual water level measurements, downloaded data logging pressure sensors, constructed permeameters, and analyzed permeameter data using computer models. Ms. Mullens submitted a UMaine CUGR proposal for summer funding in the Spring 2019 (unsuccessful). Computer models used to evaluate the impact of groundwater extraction for Northern Colombia were created and compared to field data collected by a graduate student (Efren Gomez) advised by Reeve. These models are the basis of M.S. research conducted by Mr. Gomez. Mr. Gomez has received training and advice in the application of MODFLOW, a widely used groundwater flow model, to his study area. Reeve continues to utilize groundwater data collected at the Old Town Water District's Sibley Well Field in a hydrogeology class, and provides practice field experience for students at this facility. How have the results been disseminated to communities of interest?Two presentations were made to the Earth Science community at national and regional scientific conferences. These presentations were delivered to academics, students, government employees, and industry professionals with interests in aspects of groundwater science. Reeve presented to and guided a group in August 2019 at the Orono Bog Boardwalk. This 'Nature Walk' was open to the general public and Reeve's discussion included aspects of his research activities in this peatland and other wetland systems. Reeve contributed to a Amicus (friend of the court) brief related to a Clean Water Act case being heard by the Supreme Court of the United States (County of Maui v. Hawaii Wildlife Fund). This case focuses on the potential for groundwater contamination to impact surface waters. What do you plan to do during the next reporting period to accomplish the goals? Reeve will continuing work on assessing the time series hydraulic head data. If the data can be processed in a manner that predicts visually observable anomalies in the data, the results will for formatted for submittal to a journal. Future work will focus on learning new statistical methods applicable to large data sets and applying them to the hydraulic head data. Reeve will continue working with an undergraduate student in an effort to construct a re-usable permeameter designed to measure the permeability of sediment samples in horizontal and vertical directions. I plan on submitting at least one proposal for federal funding in an effort to support ongoing groundwater work.

Impacts
What was accomplished under these goals? Hydraulic head data continues to be collected at three well clusters in Caribou Bog (Central Maine). Data from data logging pressure transducers were downloaded and manual water level data were collected from these wells. These data are being evaluated using a range of different time series methods including wavelet analysis and, more recently, machine learning algorithms (Principle Components, Local Outlier Factors, Robust Covariance), in an effort to identify anomalous patterns in the hydraulic head data hypothesized to be related to ebullition events. I am also exploring simpler methods such as moving variances and quantile range calculations. A variety of permeameters were constructed to determine the best methods to evaluate the permeability of semi-cylindrical peat samples. Construction of these devices has focused on creating a method that forces flow through the core and preventing (or accounting for) water bypasses around the core. Methods developed to date have either proven ineffective or devices degrade and allow bypass after weeks of usage. As part of this work, computer models of the peat cores were constructed that simulate the flow of water through the peat cores and are being used to calculate the peat permeability by fitting model data to laboratory measurements. A proposal on using peatlands for place-based learning was submitted to the National Science Foundation with the goal of modifying an Environmental Geology class to emphasize these systems. If funded, peatland research data will be used to make this class more relevant to students and serve as a focal point to explore local-to-global earth system interaction. This proposal is currently in review. A proposal was submitted for a Fulbright Fellowship to work in Mexico on groundwater issues in the Yucatan Peninsula. If successful, I will work with UNAM university faculty to assist with groundwater data collection and construction of computer models. This project focuses on characterizing groundwater contamination in this sole-source aquifer and the rate of groundwater and chemical movement in the aquifer.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Reeve, A. S., L. Slater, X. Comas, P. Glaser (2019) Using wavelets to identify hydraulic head anomalies associated with methane ebullition events. 2019 GSA Northeastern Section Meeting. Portland ME USA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Reeve, A. S., E. D. G�mez Ar�valo, R. P. Gordon (2019) Creating plausible groundwater flow models for the Carraipia Basin, La Guajira Department (Colombia) to aid in water resource management. GSA 2019 Annual Meeting, Phoenix AZ USA.


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:A portion of this work targeted rural water users through ongoing work with the Old Town Water District. Data and interpretations of these data have been provided to the Old Town Water District. Work completed on vernal pool hydrology targeted technical professionals working at the interface between hydrology and these wetland systems. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One graduate student completed her Masters Degree, one undergraduate is pursuing a capstone project on surface water interaction with groundwater, and one undergraduate student pursued work preparing and reviewing slides for analysis of mineral sediments in peat core samples. Data collected through this project has been incorporated into a hydrogeology class and an Environmental Geology class to provide students with realistic data for analysis. How have the results been disseminated to communities of interest?Results of work on this project have been disseminated through presentations at scientific conferences, provided to professionals at the Old Town Water District, and presented in a Thesis that is publicly available. What do you plan to do during the next reporting period to accomplish the goals?Data collection will continue at Caribou Bog and the Old Town Water District. Work on a recently funded project on groundwater dependent ecosystems will begin, including refining the scope of this project and selecting field areas for investigation of these ecosystems.

Impacts
What was accomplished under these goals? Water level and temperature data continued to be collected in Caribou Bog, and work continued assessing the application of wavelets to evaluate this time series data. Water level data collection also continued at the Old Town Water District's Sibley Well field. Two shallow wells were installed in the Stillwater River adjacent to the Old Town water District to augment data collected at the Sibley Well field for using in a Capstone project by a University of Maine Undergraduate Student. Field work with vernal pools was completed and instrumentation was removed from field sites. Graduate Student Kelli Straka wrote and completed her M.S. Thesis. A manuscript was submitted for publication and will be modified to address reviewer comments.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Reeve, A.S., X. Chen, L. Slater and X. Comas. 2017. Two Decades of Hydrogeophysical Measurements in Caribou Bog (Maine, USA) Investigating Groundwater Flow and Free-Phase (Methane) Gas. GSA Abstract #304859 - GSA Annual Meeting in Seattle, Washington, USA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Reeve, A.S. 2018. Aquifer characterization at the Sibley Well Site, Old Town Water District. Maine Sustainability and Water Conference. Augusta, Maine.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Kelli M. Straka,. 2017. Characterizing Hydrologic Fluxes in Six Central Maine Vernal Pools with a Focus on Groundwater Flow. M.S. Thesis. University of Maine.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:This work has been presented to professional scientists at two scientific conferences and has been communicated to the public through a 'nature walk' presented at the Orono Bog Boardwalk. Results have been presented at the University of Maine through Seminars and the presentation for a thesis defense. In addition, I have continued working with the Old Town Water District monitoring their well field with the goal of assessing surface-water interaction with groundwater. This groundwater is the drinking water source for the City of Old Town (Maine) and has been a field site for classroom activities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One graduate student and two undergraduate students worked on this project and were exposed to the use of data loggers, water level measurements. Undergraduate students have learned how to collected and process sediment cores. Writing and data analysis guidance was provided to the graduate student as she worked to finish her Master's Thesis. Data collected for this project was used in a hydrogeology for data analysis class. These data enhance the classroom by providing realistic (messy) data that students need to process to use for class. One site was used for classroom field trips to provide students with exposure to common tools used by hydrogeologists. How have the results been disseminated to communities of interest?Results were disseminated through conference presentations, a publication, and a 'nature walk' that Reeve leads each summer at the Orono Bog Boardwalk. What do you plan to do during the next reporting period to accomplish the goals?I will continue monitoring water levels in Caribou Bog and at the Old Town Water District. I plan to begin monitoring temperature data at Caribou Bog and the Old Town Water District to determine how groundwater interacts with surface water features located at these sites. A Masters's student will finish her graduate degree on groundwater interaction with vernal pools and is planning on submitting her work to a hydrology journal for publication. Most field sites will either be dismantled, with one or two selected for continued monitoring. Then peat core collected last summer will continue to be processed and an undergraduate student will begin to prepare and analyze slides for tephra in the ashed peat. An additional peat core will be collected for permeability testing from Caribou Bog.

Impacts
What was accomplished under these goals? Water pressure data was manually collected at eight well clusters. Continuous water pressures were collected at multiple depths in three well clusters and in shallow wells at five other locations. These water pressure data were corrected for atmospheric pressure and converted to a water elevation above mean sea level. Time series (wavelet) analysis was performed on the multi-year record of water level data to identify oscillations in the data set related to evapotranspiration and identify anomalous events that are hypothesized to be related to biogenic gas movement within and release from the peat sediments. Anomalous events occur within the peat throughout the year, with the data suggesting ebullition (gas bubbling) events decrease from spring thaw through the late fall when the peat re-freezes. An eight meter long peat core was collected from Caribou Bog and subdivided into five centimeter long sections. These sections are being processed to measure drainable porosity, bulk density, and ash content. Tephra (volcanic ash) analysis is planned for the core to determine if this could be used to date the cores and assess peat accumulation rates. Temperature and hydraulic head data were collected from six vernal pools. A heat transport computer program, further refined for this project, was used to estimate vertical groundwater velocities. Hydraulic head gradients measured at each vernal pool were also used to estimate vertical groundwater flow rates and were compared to the rates calculated using the heat transport model. The hydraulic head in each pool (surface water level) was combined with previously collected pool topography information to calculate the volume of water stored in each pool over time. These data were combined to create water budgets for each vernal pool. These data suggest that vernal pools in different regions of Maine interact differently with groundwater (e.g. different recharge and discharge functions), likely related to differences in the geology beneath the pools.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Reeve, A.S., L.D. Slater, X. Comas and P.H Glaser. 2017. Time Series Analysis of Hydraulic Head Data in Caribou Bog, Maine (USA) to Evaluate Biogenic Gas Ebullition and Other Events. Society of Wetland Scientists 2017 Annual Meeting held in Puerto Rico, June 5-8, 2017, ID# 1310
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Straka, K, A.S. Reeve and A. Calhoun. 2017. Characterizing hydrologic properties in Maine vernal pools with a focus on groundwater patterns. Society of Wetland Scientists 2017 Annual Meeting held in Puerto Rico, June 5-8, 2017 ID# 1561
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Glaser, P. H., D. I. Siegel, J. P. Chanton, A. S. Reeve, D. O. Rosenberry, J. E. Corbett, S. Dasgupta, and Z. Levy. 2016. Climatic drivers for multidecadal shifts in solute transport and methane production zones within a large peat basin, Global Biogeochem. Cycles: 15781598.