Underground Features Research Articles

Mapping shallow underground features that influence site-specific agricultural production

Modern agricultural production practices are rapidly evolving in the United States of America (USA). These new production practices present significant applications for nonintrusive subsurface imaging. One such imaging technology is GPR, and it is now being incorporated within site-specific agriculture in the detection of soil horizons, perched water (episaturation), fragipans, hydrological preferential flow paths, and soil compaction. These features traditionally have been mapped by soil scientists using intrusive measurements (e.g., soil augers, soil pits, coring tools). Rather than developing a tool for soil mapping, our studies are targeting the identification, dimensioning, and position of subsurface features that directly influence agricultural productivity. It is foreseen that this information will allow for an increase in agricultural efficiency through infield machinery automation, and it will also greatly enhance development of highly efficient crop production strategies. The field sensing methodologies that we have developed using existing geophysical technologies are highly dependent upon both the soil and site characteristics due to seasonal variations. The GPR applications presented herein were conducted primarily in a region of loess soil that extends east of the Mississippi River into western Tennessee. GPR studies were also conducted in central Tennessee on the Cumberland Plateau within a region of shallow, sandy loam soils. Additional studies were conducted on the karst area of central Kentucky. Although targeting site-specific agriculture, our results and procedures may benefit the traditional users of GPR technology. We suggest that large-scale agricultural applications of the technology would be enhanced by integrating global positioning (GPS) technology in future hardware and software products.

The use of ground‐penetrating radar to map the buried structures and landscape of the ceren site, el salvador

AbstractMore than 7800 m of digital ground‐penetrating radar data were acquired at the buried 6th century archaeological site of Ceren in El Salvador. The data were used to explore for buried structures and map the paleotopography through more than 5 m of volcanic overburden. The archaeological site consists of an agricultural village that was rapidly buried by pyroclastic debris erupted from a nearby volcano, preserving structures, plants, agricultural fields, and much of the surrounding landscape. Ground‐penetrating radar profiles were computer‐processed to remove system and background noise and time‐depth corrected to identify the reflection which represents the ancient ground surface. This buried surface, and the structures built on it, were computer‐modeled in two dimensions to aid in anomaly identification and interpretation. Twenty‐six buried structures were identified on GPR profiles and an accurate representation of the landscape and environment, as it existed just prior to the eruption, was reconstructed. Ground‐penetrating radar is an excellent geophysical tool with which to reconstruct buried landscapes and map cultural features due to its ability to accurately resolve underground features in three dimensions.

Magnetometer and Gradiometer Surveys for Detection of Underground Storage Tanks

In recent years there has been a surge of interest in methods for rapid and reliable detection and location of underground storage tanks and other cultural features related to hazardous substances in the subsurface. In the United States much of the motivation comes from recent environmental protection legislation that regulates underground storage tanks, including both existing and new installations. U.S. regulatory matters aside, ground-water contamination is a problem that knows no national borders; remediation of sites where hazardous substances can invade or have invaded ground-water supplies is a global concern. Detection and location of underground steel storage tanks can be readily accomplished using magnetometer and magnetic gradiometer surveys, which are a passive variety of remote sensing. This paper presents investigations at two sites at Hill Air Force Base, northern Utah. In each case, magnetometer and gradiometer data have proven to be valuable for assessing the possibilities of existence and location of buried underground storage tanks. Relevant magnetic-field principles are reviewed and methods of data acquisition, reduction, analysis and interpretation are described.

Bath county pumped storage project (Virginia, USA), underground features

Bath county pumped storage project (Virginia, USA), underground features