Proceedings of the 2023 Mississippi Water Resources Conference

Year: 2023 Authors: Samad M.A., Wodajo L.T., Rad P.B., Mamus M.L., Hickey C.J.

Soil erosion severely deteriorates agricultural fields by removing top fertile soil, increasing surface runoff, and reducing the soil's water-holding capacity. Increased loss of fertile agricultural land seriously threatens human habitat and livelihood, hampering agri-food production and impeding agricultural sustainability. Although soil erosion due to surficial processes (surface runoff, gully erosion, and channel erosion) is well-studied, contributions from subsurface processes such as internal soil pipes are difficult to study. As the diameter of a soil pipe increases over time, flute holes, sinkholes, and gullies develop and enhance soil erosion. Therefore, to implement early mitigation of soil erosion, it is essential to locate, map, and measure the extent of soil pipes in agricultural fields. The hidden and uncorrelated nature of soil pipes with surface features limits the applicability of remote sensing-based detection and mapping techniques. This study is conducted at a small area in Goodwin Creek Watershed, a site with established internal soil pipes, to test the applicability of two traditional geophysical methods, seismic refraction tomography (SRT), electrical resistivity tomography (ERT), and a new non-invasive acoustic method for mapping and tracking internal soil pipes. The geophysical and acoustic results were correlated with cone penetrologger (CPL) data to verify anomalies associated with internal soil pipes. The SRT indicated the location of internal soil pipe-affected zones with low seismic wave velocity anomalies. The ERT results indicated the location of soil pipe-affected zones with high resistivity anomalies. However, SRT and ERT lacked the resolution to identify individual soil pipes. The geophysical methods identified the fragipan layer that hinders the vertical flow, promotes the lateral flow of water, and accelerates the formation of soil pipes within the study area. The acoustic method identified five primary and eight secondary networks of soil pipes. Planting geophones at multiple locations, irrespective of source position, may provide the trajectory of soil pipes in the whole agricultural field.

This work was supported by the U.S. Department of Agriculture under Non-Assistance Cooperative Agreement 58-6060-6-009. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the U. S. Department of Agriculture.