Location: Watershed Physical Processes Research
2022 Annual Report
Objectives
1. Develop and implement acoustic based methods for measurement and interpretation of sediment transport in streams.
1.A. Develop novel methods for data analysis and visualization to aid interpretation of acoustic sedimentation data while continuing to develop sediment transport measurement technologies.
1.B. Engage in CEAP/LTAR research by implementing existing acoustic sediment monitoring technology in CEAP/LTAR watershed.
2. Develop and adapt acoustic and geophysical methods for characterizing soils and monitoring processes within the agricultural watershed.
2.A. Develop an acoustic based soil water status assessment tool for improving water management and irrigation and rain fed decision support systems.
2.B. Develop rapid and noninvasive agrogeophysical methods for mapping and monitoring erosional processes (e.g., soil pipes in relation to gully erosion) in agricultural landscapes.
2.C. Application of geophysical measurements for estimating groundwater flow, aquifer parameters, and aquifer thickness.
2.D. Development of relationships between soil properties and geophysical attributes using machine learning.
Approach
Development of acoustic and geophysics technology addressing gaps in the USDA's suite of tools to map and monitor hydraulic processes over a range of time and space scales will consist of: theoretical and modeling efforts, controlled laboratory experiments, and field measurements using the newly developed hardware and techniques. Theoretical and modeling efforts establish the feasibility and sensitive of acoustic attributes to soil processes and sediment transport. Laboratory measurements help to better understand the physics of soils and its interaction with water and determine optimal sensor configurations, data quality requirements, and data processing schemes. Field measurements provide the final proof of concept design and incorporation into USDA applications. The first objective relates to the development of novel methods for data analysis and visualization to aid interpretation of acoustic sedimentation data while continuing to develop sediment transport measurement technologies. The second objective relates to acoustic and geophysical methods that can monitor and evaluate the performance of agricultural irrigation, drainage, and rain-fed systems, improve technology for studying soil pipe development, and to assess suitable sites and monitor the efficacy of surface water to groundwater interaction. Both parties are actively engaged in independent research projects related to the development and use of acoustic/ seismic technology for water resources applications. The parties agree that meeting the objectives of this project will expand the suite of tools, technology, and sensors for acquiring data to support science-based decision support systems.
Progress Report
This is a new project which replaced project 6060-13000-027-000D, "Utilizing Acoustic and Geophysics Technology to Assess and Monitor Watersheds in the United States." Please refer to 6060-13000-027-000D for additional information
Progress on Objective 1A: Experiments investigating the bioactivity of algae and its effect on acoustic attenuation were initiated in April 2022 at The University of Mississippi Biological Field Station in conjunction with an ARS project in Oxford, Mississippi that was focused on measuring algae activity based on controlled nutrient ratios. National Center for Physical Acoustics (NCPA) investigators are studying the potential effect of algal movements on acoustic attenuation measurements of suspended sediment concentration and the potential use of the acoustic system to monitor algal activity. Two Single Frequency Acoustic Attenuation Systems were deployed; one unit was in an experimental limnocorral, and the other unit was placed outside of the limnocorrals but in the same pond. These deployments should provide data that can be used to isolate the effects of algae on acoustic attenuation relative to other properties of the water in the pond.
Progress on Objective 1B: National Center for Physical Acoustics researchers have installed the Single Frequency Acoustic Attenuation System at Goodwin Creek, Station 1 in Panola County, Mississippi in November 2021. This site is an ARS managed Conservation Effects Assessment Project/Long-Term Agroecosystem Research watershed which collects intermittent physical samples from Goodwin Creek. The Single Frequency Acoustic Attenuation System and pump sampler were triggered by stage height. Hardware repairs have made to multiple units available for field deployment, which expands the ability to deploy the system at other points of interest.
Progress on Objective 2A: A sprinkler irrigation system along with the capability of soil moisture content and matric potential measurements was built near the National Center for Physical Acoustics on the University of Mississippi campus. At this test site, an improved high-frequency multichannel analysis of surface wave method consisting of a 32-geophone array was employed to obtain temporal variations in soil profiles during irrigation. Preliminary tests were conducted, and a database of the high-frequency multichannel surface wave results for irrigation scenarios has been built, including a daily fluctuation test and irrigation tests from dry to fully saturated soil conditions. The goal of these tests was to evaluate the sensitivity of the measurement system and to obtain a fully saturated soil condition. Irrigation testing requires a dry soil condition, which could not be achieved in the winter and spring of 2022. In the upcoming summer when the soils are dry, irrigation tests will be conducted with time-lapse high-frequency multichannel analysis of surface wave measurements in 1-minute intervals before, during, and after irrigation practices. The soil profiles will be subtracted from the background image to determine the deviation from the fully saturated soil condition and to evaluate the performance of irrigation.
Progress on Objective 2B: A new approach to using acoustics to map underground voids called soil pipes was tested at the Goodwin Creek watershed in Panola County, Mississippi. This method uses a loudspeaker to direct sound into an eroded surface in a gully, and the resulting ground vibration due to the propagation of the acoustic wave within the soil pipe was measured using geophones on the surface. The coupling of acoustic energy to seismic energy depends on the size of the soil pipe and the properties of the soil, and measurements of acoustic wave movements in an area can be used to find the soil pipes. The location of soil pipes using the acoustic method was in good agreement with locations found using intrusive cone penetration tests.
Progress on Objective 2C: An 80-electrode remote self-potential survey was conducted at a groundwater extraction site near the Little Tallahatchie River in Shellmound, Mississippi. The extraction well, part of an aquifer storage and recovery pilot project, is located about 40 meters from the river and extracts groundwater from the Mississippi River Valley Alluvial Aquifer. Self-potential measurements during a pumping test were obtained using a measurement system developed at The University of Mississippi National Center for Physical Acoustics. The data showed that the direction of groundwater movement could be detected using the system; furthermore, aquifer characteristics such as hydraulic conductivity can be estimated. This preliminary study suggests that self-potential data can be used to identify surface-groundwater movement and interaction.
Progress on Objective 2D: Correlations between geophysical and geotechnical parameters allow for a more thorough assessment of the condition of watershed infrastructure. However, interpretation of geophysical data can lead to multiple scenarios since the mathematical solution is not unique. One approach to reducing this non-uniqueness is to use information from multiple geophysical methods to detect the geotechnical properties of the soil. An artificial neural network (ANN) model was developed to extract geotechnical properties (water content, dry density, saturation, and water content) by combining geophysical parameters (electrical resistivity, P-wave velocity, and S-wave velocity). In this approach, all three geophysical parameters were used to predict the different geotechnical properties of different compaction regions of earthen dams. This study showed that the prediction of water content, dry density, saturation, and void ratio using combinations of the three geophysical parameters was better than using a single geophysical parameter. Results and data from this study have been used to extend the database for artificial neural network (ANN) model development and validation.
Accomplishments
1. Acoustic system for measurement of suspend sediment in streams and rivers. In order to more accurately use the Single Frequency Acoustic Attenuation System to monitor suspended sediment in natural systems, the effect of algae on acoustic signal attenuation must be quantified. In collaboration with ARS scientists in Oxford, Mississippi, multiple Single Frequency Acoustic Attenuation units were installed in a pond with populations of algae that were controlled by adding different amounts of nutrients. Trends in acoustic data were observed, and the trends are likely due to movements and changes in population of the algae. These observations will help to make sediment concentration measurements in natural streams with significant algal populations more accurate. Furthermore, the ultrasonic device has potential for monitoring algae activity which would prove useful in water quality and ecology studies.
2. Acoustic measurements of algae in surface waters. Monitoring suspended sediment transported in rivers and streams can be difficult and expensive, and typical methods of physical sampling result in relatively short data sets with large time gaps between samples. In collaboration with ARS scientists in Oxford, Mississippi, the Single Frequency Acoustic Attenuation System was deployed to collect near-continuous data to estimate the concentration of suspended sediment in Goodwin Creek near Batesville, Mississippi. The system was installed at a USDA monitoring site alongside a dedicated pump sampler. Results to date have shown that the acoustic data provides more frequent measurements over longer time periods than was possible for the physical samples. The results for the acoustic system agreed with the physical samples. The acoustic system is robust and should be operational for years with minimal regular maintenance, providing information for stakeholders to make more accurate estimates sediment transported by the stream, which can be used to help evaluate soil losses in the surrounding watershed.
3. Measuring soil properties using an acoustic soil profiler. In agricultural land management, it is useful to have a non-invasive tool for soil profile measurement so that soil preparation and amendments can be applied properly. In collaboration with ARS scientists in Oxford, Mississippi, an acoustic soil profiler has been developed. This acoustic tool uses non-invasive surface mounted sensors to provide shear wave velocities in the soil profile to a depth of 2.5 meters. Researchers have found that the shear wave velocity is related to soil mechanical and hydrological properties. Therefore, the shear wave velocity profiles reflect temporal and spatial variations of soils due to seasonal and weather effects, geological anomalies, and from farming activities such as compaction and irrigation. This acoustic soil profiler can be used as a portable tool for soil scientists and farmers for land management as well as in environmental and civil engineering applications.
4. Acoustic location of internal soil pipes in fields. The direct contribution of internal soil piping to soil losses or their collapse to form ephemeral gullies is a vital component in understanding total soil loss from agricultural lands. The hidden and uncorrelated nature of occurrences of internal soil pipes limits the applicability of manual and remote sensing-based techniques. In collaboration with ARS researchers in Oxford, Mississippi, a new approach of using acoustic methods to map internal soil pipes was tested. The method uses sound rather than a fluid tracer and measures the ground surface vibrations instead of visually observing tracer dyes in cut trenches, which means that the method is less invasive and faster than traditional tracer tests. This methodology provides an alternate measurement approach for locating soil pipe networks which can be used to target erosion control measures to limit soil losses from agricultural lands.
5. Non-intrusive measurements of groundwater flow. Groundwater depletion due to irrigation increases the need to identify optimal locations and approaches for managed aquifer recharge and to develop better estimates of goundwater storage capacity. In collaboration with ARS researchers in Oxford, Mississippi, an 80-electrode remote self-potential system has been developed and successfully tested at an aquifer storage recovery project in, Shellmound, Mississippi. The system can automatically measure self-potential changes in space and time over an extended period and transfer data to a base station over the internet. Preliminary results indicated that the system can non-intrusively detect and monitor groundwater flow and estimate aquifer parameters. Use of these measurements in conjunction with traditional hydrogeological exploration will allow for better quantification of groundwater resources that are a vital part of agricultural production.
6. Improving geophysical information using artificial neural networks (ANN). The need for characterizing soil properties is driving the development of geophysical measurement methods and proximal soil sensing technologies. The relationships between geophysical parameters and soil properties need to be improved in order optimize the use of geophysical information in agricultural research. A laboratory program in collaboration with ARS researchers in Oxford, Mississippi, is acquiring the data necessary for ANN development so that the ability to quantify soil properties using geophysical methods can be improved. Current measurements focus on the soil type, moisture content and degree of compaction in relation to electrical resistivity and seismic methods. The relationships facilitate the use of geophysical information that can lead to faster measurements of soil properties over larger areas.
Review Publications
Bakhtiara, R.P., Hickey, C. 2022. Utilizing CRS stack for enhanced near-surface seismic reflection imaging: Examples from consolidated and unconsolidated environments. Geophysics. 87(5):1-91.
Naderyan, V., Hickey, C., Raspet, R. 2016. Wind-induced ground motion. Journal of Geophysical Research: Solid Earth. 121(2):917-930. https://doi.org/10.1002/2015JB012478.
Rittgers, J.B., Revil, A., Mooney, M.A., Karaoulis, M., Wodajo, L., Hickey, C. 2016. Time-lapse joint inversion of geophysical data 1 with automatic joint constraints and dynamic attributes. Geophysical Journal International. 207(3):1401-1419. https://academic.oup.com/gji/article/207/3/1401/2194601?searchresult=1.
Samad, M.A., Wodajo, L., Bakhtiari, R.P., Mamud, M., Hickey, C. 2012. Integrated agrogeophysical approach for investigating soil pipes in agricultural fields. Journal of Environmental & Engineering Geophysics. 27(14):2032–2040.
Raspet, R., Hickey, C., Koirala, B. 2022. Correct tilt calculation for atmospheric presure-induced seismic noise. Applied Sciences. 12(3):1247. https://doi.org/10.3390/app12031247.
