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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #436037
Research Project: Acoustic and Geophysical Methods for Multi-Scale Measurements of Soil and Water Resources

Location: Watershed Physical Processes Research

Title: Investigating the effects of suspended algal content, dissolved oxygen, and temperature on a high-frequency acoustic attenuation system in a controlled laboratory environment

Author
item WATSON, NOAH - University Of Mississippi

Submitted to: PhD Dissertation
Publication Type: Other
Publication Acceptance Date: 5/11/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: This study evaluated factors that may influence the accuracy of the Single Frequency Acoustic Attenuation System (SFAAS), a technology that uses sound waves to estimate the amount of fine sediment suspended in streams. The results showed that water temperature significantly affects the acoustic measurements and should be included in site-specific calibrations, while dissolved oxygen has little to no impact. Algal concentration appears to have only a minor effect, although additional research is needed to confirm its influence. These findings enhance the reliability of sediment monitoring and provide the United States Department of Agriculture researchers and conservation managers with more dependable data to evaluate soil erosion, assess water quality, and support the effectiveness of conservation practices.

Technical Abstract: The Single Frequency Acoustic Attenuation System (SFAAS) has been developed at the National Center for Physical Acoustics (NCPA). This system uses acoustic methods to monitor fine suspended sediment concentration in streams. Site-specific calibrations are necessary for this system, and previous research has indicated that algal concentration or dissolved oxygen concentration of water may affect collected data. Temperature, dissolved oxygen concentration, and fluorescence, used as a proxy for algal concentration, were monitored during this system’s use, and calibrations were derived to account for the effect of each of these variables on acoustic measurements. It has been shown that temperature has a significant effect on acoustic measurements, while dissolved oxygen concentration has no discernible effect. The effect of algal concentration is slight and subject to further research.