ARS | Publication request: CONTINUOUS SOIL LOSS MONITORING USING TURBIDITY SENSORS

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2004
Publication Date: October 31, 2004
Citation: Dabney, S.M., Locke, M.A., Steinriede Jr, R.W. 2004. Continuous soil loss monitoring using turbidity sensors. Agronomy Abstracts. 3383. CD-ROM 2004.

Technical Abstract: Soil loss is usually determined by measuring runoff rate and periodically collecting either a single composite sample or several sequential samples. Optical backscatter turbidity sensors offer the opportunity to obtain a continuous record of soil loss if turbidity is well correlated with sediment concentration. The relationship between turbidity and sediment concentration depends on several factors, including: particle size, particle shape, and particle color. As watershed size is reduced to the scale of individual fields or plots, variability in particle composition is reduced and the relationship between turbidity and concentration may become stable. We undertook studies to determine this relationship for several soils. We compared both suspensions of dried soil samples and sequential natural rainfall runoff samples. We obtained a strong correlations between turbidity and concentration, but the relationship differed between runoff and resuspended samples. For natural runoff samples, the relationship did not vary with discharge rate, but peak turbidity usually preceding peak flow rate. Our preliminary results suggest that optical backscatter turbidity sensors have good potential for continuously monitoring soil loss and improving field scale soil loss estimates.