TDE Climate Data

TDR data for 0-35 cm:

Measurements of soil water content at all grid points for contour plots.

1.0 DOCUMENT INFORMATION
1.1 Document Title: TDE Soil Water Data By TDR for 0-35 cm
1.2 Revision Date: 23 August, 2005
1.3 Document Summary: Periodic measurements of soil water content by TDR for the 0-35 cm depth increment throughout the period from 1993-2000.
1.4 Sponsor: Office of Biological and Environmental Research, U. S. DOE

2.0 INVESTIGATOR
2.1 Investigator and data set contact:

P.J. Hanson (hansonpj@ornl.gov)
Environmental Sciences Division
Oak Ridge National Laboratory
Building 1059, P.O. Box 2008
Oak Ridge, TN 37831-6422

2.2 Title Of Investigation:
Walker Branch Throughfall Displacement Experiment (TDE)

3.0 DATA SUMMARY
Soil water content data by date, treatment, and specific positions across the slope of the TDE experimental site for the 0-35 cm depth increment.

4.0 PROCEDURES
Soil water content (%, v/v) was measured with a time domain reflectometer (TDR; Soil Moisture Equipment Corp., Santa Barbara, California) following the procedure of Topp and Davis (1985) as documented for soils with high coarse fraction content (Drungil et al. 1987). Three hundred ten sampling locations were installed at an 8 x 8 meter spacing across the site giving more than 100 soil water monitoring locations per plot. At each location two pairs of TDR waveguides were installed in a vertical orientation (0-0.35 and 0-0.7 m). The surface (0-0.35 m) TDR measurements coincide with the zone of maxium root density in these soils. TDR measurements were obtained biweekly during the growing season and approximately monthly during the dormant season. The TDR soil water content measurements were adjusted for the coarse fraction of these soils (mean coarse fraction of 14%) and converted to soil water potentials using laboratory derived soil moisture retention curves for the A, A/E and E/B horizons (Hanson et al. 1998).

5.0 OBSERVATION NOTES
None

6.0 DATA ORGANIZATION

Data are provided in comma delimeted text files where the first line includes the variable names and subsequent lines include the following data by month.

6.1 Variable, Definition, and Units

Column 2 = Slope
TDE slope postion where 1 = lower, 2 = middle, and 3 = upper slope positions.

Column 3 = Y
Y coordinate position on the slope in arbitrary units 1-10.

Column 4 = X
X coordinate position across the slope in arbitrary units 1-31.

Column 5 = YM
Y coordinate position on the slope in meters (0-72m).

Column 6 = XM
X coordinate position across the plots in meters (0-240 m).

Column 7 through the end of the file = Y??d???
Soil water content data for the indicated year and day of the year at a specific XY position on the TDE experiment site.

6.2 Number of Records: 168 dates; >41,000 observations.
6.3 Missing data: Missing data are present and represented by blanks between commas.
6.4 Related Data Sets: Similar data are available for the 0-70 cm depth increment and summary data by year, date, and treatment are also provided.

7.0 KNOWN ERRORS AND QUALITY ASSESSMENT
These daily data have been checked for errors. Bad data and missing data are both represented by empty cells within the data matrix.

8.0 NOTES
8.1 Limitations of the data:     None.
8.2 Known Problems With The Data:     None.
8.3 Usage Guidance:     None.

9.0 REFERENCES:

Hanson, P.J., D.E. Todd, N.T. Edwards, and M.A. Huston. 1995. Field performance of the Walker Branch Throughfall Displacement Experiment, In: A. Jenkins, R.C. Ferrier, and C. Kirby, eds., Ecosystem Manipulation Experiments: scientific approaches, experimental design and relevant results, Ecosystem Research Report #20, Commission of the European Communities, pp. 307-313.

Hanson, P.J., D.E. Todd, M.A. Huston, J.D. Joslin, Jennifer Croker, and R. M. Augé. 1998. Description and field performance of the Walker Branch Throughfall Displacement Experiment: 1993-1996, ORNL/TM-13586, Oak Ridge National Laboratory, Oak Ridge, Tennessee.

Hanson P.J. 2000. Large-scale Water Manipulations -- chapter 23 In: O.E. Sala, R.B. Jackson, H.A. Mooney, and R.W. Howarth, eds. Methods in Ecosystem Science, Springer-Verlag, New York. pp. 341-352.

Hanson, P.J. , D.E.Todd and J.S. Amthor. 2001. A six year study of sapling and large-tree growth and mortality responses to natural and induced variability in precipitation and throughfall. Tree Physiology (in press).

10.0 DATA LISTING

Click on the following to view data for the listed year.
Once open the files can exported as text files with the 'Save As' command.