Instrumentation/Data Collection
- All data have been acquired and
geolocated with a differential global positioning system. Over 1,700 surface soil cores have been extracted (1999-2001) for determining chemical concentrations as
well as physical properties.
- Over 40 km (25 mi) of ground penetrating radar (GPR) have been collected and analyzed.
- Electromagnetic
induction (EM-31 and EM 38) have been collected at either 5 or 15 m (16 or 49 ft) grids.
- Soil moisture observations are collected at
several different scales (over 36,000 measurements each day).
- Induced polarization techniques are being conducted to characterize water dynamics.
- The site contains
two micro-meteorological stations that have the entire energy balanced measured (global and net radiation, tipping bucket rain gage, soil heat
flux plates, temperature and vapor pressures at several heights, and wind speed).
- During the first two weeks after chemical application, vapor
flux towers are also in operation.
- Several techniques are being evaluated and compared to pesticide air density measurements which are
collected every 1 to 2 hours at five heights above the soil surface.
- Water and chemical (NO3, P, pesticides) runoff are collected at each of the four
watersheds.
- Over 80 solution samplers and 52 observation wells were installed in the production fields to sample water composition flowing along the clay lens.
- The spatial structure of corn
grain yields were compared to measured yields using a grain combine equipped with a GPS receiver and a yield monitor.
- Ground, tower, aircraft and satellite remote sensing imagery are collected periodically.
- Plant growth and development are measured several times each growing season.
- 180 observation wells for riparian wet-land were installed.
- Extensive ground surveying of the entire watershed was performed using a Topcon total station.
- Five permanent stream monitoring/sampling stations were installed at intervals along the stream channel within the riparian zone. Stream flows are logged in real time and evaluated, and chemical fluxes in the stream are measured.
- Wetland soil cores were extracted with a peat sampler, and analyzed for grain size, bulk density, carbon content, hydraulic conductivity, water content, and denitrification potential.
- Dissolved gas was measured in groundwater samples obtained throughout the wetland, for evidence of denitrification and methanogenesis. Samples are analyzed for dissolved oxygen, dinitrogen, nitrous oxide, and methane.
- Stream water and groundwater samples are analyzed for nitrate, sulfate, and chloride using an Ion Chromatograph (IC).
- Nine trees within the wetland have been instrumented with Thermal Dissipation Probes that directly measure tree sap flow rates. These can then be used to estimate evapotranspiration (ET) within the riparian zone.
Remote sensing activities include color infrared and hyperspectral imaging flights several times during the growing season. Supporting ground data measurements include leaf area index, plant height, leaf reflectance and transmittance, soil reflectance, and leaf chlorophyll concentration.
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Installation of runoff flume for OPE3 |
