Student Level & Background INVESTIGATING ARID ZONE HYDROLOGIC SYSTEMS AT THE LOCAL RIPARIAN TO REGIONAL BEDROCK SCALE: MULTIDISCIPLINARY INSTRUCTION THROUGH DATA ANALYSIS AT THE UNIVERSITY OF MISSOURI’S BRANSON FIELD CAMP Robert Bauer*, Donald Siegel**, Laura Lautz**, Dennis Dahms***, Eric Sandvol*, James Luepke* and Len Payne* *Dept. of Geological Sciences, University of Missouri, Columbia, MO, 65211 (e-mail to bauerr@missouri.edu) **Dept. of Earth Sciences, Syracuse University, Syracuse, NY 13244 *** Dept. of Geography, Northern Iowa University, Cedar Fall, IA 50614 The Project Area – is in the Red Canyon on the southeastern margin of the Wind River Mountains in Wyoming. The property is owned and managed by The Nature Conservancy Project Components & Data Collection Mapping stream terraces adjacent to Red Canyon Creek Evaluating soil profiles Determining the relative topographic relationships among the terraces Seismic refraction profile adjacent to Red Canyon Creek Correlating seismic models with Geoprobe core logs Red Canyon Creek project site Abstract Wind River Mountains During the past four years at the Branson Field Laboratory, we have developed projects that integrate a broad range of hydrologic, hydrogeologic, and geochemical skills with field mapping and shallow subsurface analysis. Our educational philosophy is to introduce our students to a broad range of skills and methods within the context of continually changing discovery. Each year's work is conditioned on the results of the previous year's results; students are involved in new inquiry-based research every year. The study area, a riparian wetland research area managed by The Nature Conservancy of Wyoming, is located in scenic Red Canyon, near Lander, Wyoming. The canyon is drained by the now underfit Red Canyon Creek. Five alluvial units adjacent to the creek include four Pleistocene cut terraces through Triassic redbeds and one Holocene fill terrace. The creek has a series of beaver dams within tight meanders. The study project involves four segments of data collection and analysis: 1) mapping of the alluvial terraces, 2) installing and monitoring shallow test wells using a Geoprobe®, 3) conducting in-stream tracer tests, and 4) obtaining shallow seismic refraction profiles. Students and faculty participate in an integrated effort to characterize hydrologic relationships within a well defined stretch of Red Canyon Creek. In two of the meanders, borings into fine-grained floodplain deposits are collected and analyzed, and piezometers or water table wells are installed. Stratigraphic data, water levels in piezometers and wells, and all-day in-stream tracer testing have identified a wetland hyporheic zone with short-term flow paths to and from the water table and the stream. Seismic refraction profiles suggest that there are buried stream channels and point bars beneath the surficial silt that may produce locally complex short-term flow paths. Next year we will use high resolution seismic reflection profiles and selected new monitoring wells to test this hypothesis. Project Components & Data Collection Shallow well boring and construction using Geoprobe® direct-push boring and collection tools Well site data collected by the students - logs of the recovered cores - water levels in each well - bail and slug test data for hydraulic conductivity Data Analysis and Reports P-9 P-10 5564 5566 5568 5570 5572 5574 5576 5 10 15 20 25 30 35 40 45 S&G Sandy silt + sand S N MW-7/P-6 MW-8/P-7 MW-5/MW-6/P-1 MW-9/P-8 Red Canyon Creek 50 55 5570.67 5570.65 5570.50 5570.46 5570.69 5570.53 5570.22 5570.07 5570.05 5570.18 5571.8 5570.5 5570.3 5570.7 Silt with S and G 5570.9 Monitoring Well Piezometer Dam 30 meters P-5 P-3 P-4 P-2 S-4 S-1 S-2 5571 5571.5 5569 DS+JM 6-28-02 A’ A B B’ Flow Direction Water Table Contour (ft) The Final Group Report includes sections on: Surficial Geology - Describing the surficial terrace map units and how they are related to the creek, (includes a map). Surface water hydrology - Describing results of the stream data analysis, including a determination of whether discharge increases or decreases down the stream and whether the measurements agree. The students must determine whether the stream loses or gains water based on their streamflow measurements. The report includes plots of dye tracing results, stream cross section, and calculations of discharge Groundwater hydrology - Describing the water table, including a water table map at Red Canyon Creek with flow lines, and a determination of whether the stream is losing or gaining ground water. The report must indicate whether the groundwater data agree with conclusions based on streamflow measurements. The report includes calculations for hydraulic conductivity, and a calculation of how much groundwater is moving per year (in cubic feet/yr) to or from the creek along the creek stretch from the dam to the first downstream bend. Surficial Geochemistry – Including a determination of whether the groundwater adjacent to Red Canyon Creek is anoxic or oxic, and an evaluation of what major minerals are dissolving to create the kind of waters in the stream and in the ground. The report includes Stiff diagrams to demonstrate this point. Seismic Refraction – Including a model for the subsurface along the seismic profile Each year’s work is conditioned on the results of the previous year; the students are involved in new inquiry-based research every year. Student Level & Background Project Learning Objectives Field chemical data from water samples collected from each of the bored wells pH in ground water and stream water Specific conductance Ferrous iron Dissolved oxygen Students who participate in the course: are typically juniors or seniors working toward a BS degree in the geological sciences Pre-requisites for the course include: Historical Geology, Sedimentology, and Structural Geology. Project background provided onsite: By the time the students start the project, they have already completed projects on the stratigraphy and sedimentology of the Mesozoic rock units that occur at the site, and they have mapped folded and faulted rock Mesozoic rock units in adjacent areas. Project lectures provided onsite: Since the course has no course pre-requisites in hydrogeology or geophysics, all techniques and background in these areas are provided through onsite lectures and demonstrations. Our main project objective: To help students learn about the relationships between surface water and groundwater in the hyporheic zone by collecting and analyzing data from multiple sources. Associated objectives include: -- Helping students understand the importance of integrating multiple techniques and datasets to address a general problem. -- Teaching students how to collect and analyze data using a wide variety of techniques that bear on a problem. -- Teaching students to work effectively as a group (The students work in a single three-person group for the entire 5-day project.) Surface flow data from to determine discharge using three different techniques Degree of dilution of tracer Concentration curve integration Channel velocity/Area measurements