|TIMLIN, DENNIS -|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 1999
Publication Date: December 1, 1999
Citation: WILLIAMS, R.D., BROWN, M.A., TIMLIN, D.J. 1999. THE EFFECT OF DATABASE ERRORS ON ESTIMATES OF PEDO-TRANSFER COEFFICIENTS. AGRONOMY ABSTRACTS. Volume(91)Abstract p. 126. Interpretive Summary: Abstract Only.
Technical Abstract: Pedo-transfer functions are used to estimate unknown from known soil properties. Pedo-transfer functions derived in this manner are developed from large databases to make the regression models universal and robust. However, how do the variations in techniques used to measure the soil properties, or the errors present in the database affect the estimates? Here we used a large unmodified database, and then modified the database b introducing errors in selected parameters. Part of each database was used to develop the regression models. The remaining data are used to test the regression models and determine psi (thrta) estimation errors. The data bases are then randomized and the procedure repeated. Using this approach the robustness and precision of the regresion models, as reflected in the quality of the data, can be determined. Results will be discussed.