Two new papers are available in Water Resources Research on water travel time estimation in catchments. Both represent collaborations with colleagues to advance techniques in understanding the transient nature of travel time distributions. We’re getting closer and closer to answering the question: how old is that water in the stream?
Rinaldo, A., Benettin, P., Harman, C., Hrachowitz, M., McGuire, K., Van der Velde, Y., Bertuzzo, E., Botter, G., 2015. Storage selection functions: A coherent framework for quantifying how catchments store and release water and solutes, Water Resources Research, doi: 10.1002/2015WR017273.
Klaus, J., Chon, K.P., McGuire, K.J., McDonnell, J.J., 2015. Temporal dynamics of catchment transit times from stable isotope data, Water Resources Research, doi: 10.1002/2014WR016247.
Kevin, Brian, and I installed a reverse osmosis filtration system, an irrigation line, an electrical line, and several data instruments/loggers. This included pounding a 7-foot copper grounding rod into the ground. The filtration system is used to change the chemistry of local tap water to resemble that of rainfall for our experiment. Sunny weather, with only an occasional thundershower, helped the installation move on schedule.
There was quite a bit of vegetation growing in the soil model, to our surprise! It could have been due to warmth inside the hoop-house. I clipped the vegetation and Brian sprayed an herbicide to suppress future growth. Now that most of the infrastructure is built, I am thinking about the next trip to Coweeta, when I will install the rest of the instrumentation: (3) soil moisture and temperature probes, (3) tensiometers, (12) lysimeters, (5) rain gauge tipping buckets, and (1) piezometer; hundreds of meters of extension cables; and dozens of batteries!
Soil model when we first arrived. Note the growth of vegetation.
Raymond pounding a 7-foot copper grounding rod into the floor for the data logger, which will be connected to soil temperature and moisture probes and tensiometers.
Kevin and Brian installing sprinkler heads for the irrigation system.
Soil model with sprinkler heads, electrical line, meteorological station installed.
Construction on the soil model at Coweeta Hydrologic Laboratory has begun! We will be using the model for a water and nutrient reaction and transport experiment to answer questions, such as: What is the dominant process (e.g., biogeochemical or hydrologic) for controlling export of nutrients from a hillslope? Under what conditions can we expect these controls to change? How does subsurface flow vary spatially along a hillslope?
The model was built for an experiment by John Hewlett and Alden Hibbert in 1963 to measure and describe nonstorm flow of water through soil along a hillslope to support base flow generation. (A picture of a similar, precursor soil model, used by John Hewlett and Lloyd Swift in 1961, is shown.) The model has not been used since then.
Kevin, Brian, and I surveyed the model—it looked good—and cleaned up leaf litter and debris around it. Then we constructed a hoop-house, a shelter made from lumber, rebar, PVC pipes, and a large plastic sheet (which weighed over 100 pounds!). Guy-ropes held it in place. The hoop-house is designed to keep out rain while letting in sunlight. Nobody was hurt during the field trip, although the hillslope was steep and slippery, the stairway narrow, and the weather wet.
Lloyd Swift (left) and Alden Hibbert (?) (right) at a similar soil model in 1961.
Kevin (left) and Raymond (right) at the soil model in 2015.
Brian supporting Raymond, while he pounds in PVC pipe for the structure of the hoop-house.
Kevin and Brian adjusting the guy rope.
Completed hoop-house, which is designed to keep out precipitation while letting in solar radiation.
Kris Brown had another paper published. The study evaluated the model Water Erosion Prediction Project (WEPP) in predicting event-based sediment yield and runoff for a series of rainfall experiments on six stream-crossing sections of forest roads with different intensities of best management practices. For more information, please check out the paper.
Brown, K.R., McGuire, K.J., Hession, W.C., and Aust, W.M., 2015. Can the Water Erosion Prediction Project (WEPP) model be used to evaluate BMP effectiveness from forest roads? Journal of Forestry, doi: 10.5849/jof.14-101.
Brian McGlynn from Duke University visited the lab last week. Brian gave a great seminar that was co-hosted by ICTAS and the Water Center. It was well attended and generated great discussion. We all thank Brian for coming to visit us at Tech.
Water quality, soils and fluvial geomorphology of a headwater stream network
Seeking 4 undergraduate student researchers for National Science Foundation funded REU program at the Hubbard Brook LTER site in New Hampshire.
Project description: Where do forests end and streams begin? This seemingly simple question turns out to defy an easy answer. Headwater streams, such as those at Hubbard Brook, comprise the vast majority of riverine miles, set regional water quality, and represent the interface between terrestrial and aquatic systems. As a team, we will explore the vast network of headwater streams across the Hubbard Brook Valley and their relationships to their tributary watersheds. Students will participate in both group and individual research. For the group project we will come together as a team several times during the program to sample portions of the Hubbard Brook tributary stream network at a fine spatial scale over a short time period. These “snap shots” will be used to decipher potential mechanisms that regulate spatial water quality patterns. Each student will also develop an individual project based on the student’s interests and background. Individual projects could include (1) mapping stream channel geomorphology and exploring relationships to topography and streamflow quantity, (2) measuring hydrologic exchange between streams and groundwater, and (3) characterizing variation in soil morphology and chemistry in streamside environments. Skills in GIS, field survey and mapping, soil description and sampling, and water sampling and analysis will be practiced and developed.
Project mentors include: Drs. Kevin McGuire, Scott Bailey, Mark Green, Denise Burchsted. REU students will also work closely with Ph.D student Carrie Jensen.
Applications are due February 6, 2015.
For application information go to http://hubbardbrookreu.org and for project inquiries, contact Kevin McGuire.
Maggie Burns doing slug tests in her wells.
Geoff Schwaner (hydroped technician) dragging the antenna.
Preparing to hike equipment to remote locations.
Maggie Zimmer sampling wells.
Summer high flow event.
Kevin and Maggie recreating on the lake.
Watershed 3 summer crew – 2011.
Tyler taking a break from field work and hiking in the Whites.
Pleasant View Farm Crew, 2012
Watershed 3 soils crew, summer 2009.
McGuire is co-convening a session with Josie Geris, Daniele Penna, and Julian Klaus called “New Developments in Tracer Applications in Catchment Hydrology.” If you are attending the meeting next week, please come to our session. The program is available below:
Papers – Tuesday, Moscone West
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Posted in Meetings
Tagged with: AGU
Abstract: We examine how tracer studies have enhanced our understanding of flow paths, residence times and sources of stream flow in northern catchments. We define northern catchments as non-glacial sites in the temperate conifer/boreal/permafrost zone, focussing our review mainly on sites in North America and Europe. Improved empirical and theoretical understanding of hydrological functioning has advanced the analytical tools available for tracer-based hydrograph separations, derivation of transit time distributions and tracer-aided rainfall-runoff models that are better able to link hydrological response to storage changes. However, the lack of comprehensive tracer data sets still hinders development of a generalized understanding of how northern catchments will respond to change. This paucity of empirical data leads to many outstanding research needs, particularly in rapidly changing areas that are already responding to climatic warming and economic development. To continually improve our understanding of hydrological processes in these regions our knowledge needs to be advanced using a range of techniques and approaches. Recent technological developments for improved monitoring, distributed hydrological sensor systems, more economic analysis of large sample numbers in conjunction with novel, tracer-aided modelling approaches and the use of remote sensing have the potential to help understanding of northern hydrological systems as well as inform policy at a time of rapid environmental change.
Tetzlaff, D, Buttle, J., Carey, S.K., McGuire, K., Laudon, H., Soulsby, C. 2014. Tracer-based assessment of flow paths, storage and runoff generation in northern catchments: a review, Hydrological Processes, doi: 10.1002/hyp.10412.
A paper from Cody Gillin’s master’s thesis was accepted last week. The manuscript titled “Mapping of hydropedologic spatial patterns in a steep headwater catchment” will be published in a special issue on hydropedology in the Soil Science Society of America Journal. This paper appears in the special issue with another paper on the same project, which was led by Rebecca Bourgault from the University of Vermont.
Gillin, C.P., Bailey, S.W., McGuire, K.J., Gannon, J.P. 2015. Mapping of hydropedologic spatial patterns in a steep headwater catchment, Soil Science Society of America Journal, doi: 10.2136/sssaj2014.05.0189.
Abstract: A hydropedologic approach can be used to describe soil units affected by distinct hydrologic regimes. We used field observations of soil morphology and geospatial information technology to map distribution of five hydropedologic soil units across a 42 ha forested headwater catchment. Soils were described and characterized at 172 locations within watershed 3, the hydrologic reference catchment for the Hubbard Brook Experimental Forest, NH. Soil profiles were grouped by presence and thickness of genetic horizons. Topographic and bedrock metrics were used in a logistic regression model to estimate the probability of soil group occurrence. Each soil group occurred under specific settings that influence subsurface hydrologic conditions. The most important metrics for predicting soil groups were Euclidean distance from bedrock outcrop, topographic wetness index, bedrock-weighted upslope accumulated area, and topographic position index. Catchment scale maps of hydropedologic units highlight regions dominated by lateral eluviation or lateral illuviation, and show that only about half the catchment is dominated by podzolization processes occurring under vertical percolation at the pedon scale. A water table map shows the importance of near-stream zones, typically viewed as variable source areas, as well as more distal bedrock-controlled zones to runoff generation. Although the catchment is steep and underlain by soils developed in coarse-textured parent material, patterns of groundwater incursion into the solum indicate that well drained soils are restricted to deeper soils away from shallow bedrock and the intermittent stream network. Hydropedologic units can be a valuable tool for informing watershed management, soil carbon accounting, and understanding biogeochemical processes and runoff generation.