Debra L. Gamble

Performance of Hybrid and Single-frequency Impulse GPR Antennas on USGA Sporting Greens

ABSTRACT The utility of employing ground-penetrating radar (GPR) technologies for environmental surveys can vary, depending upon the physical properties of the site. Environmental conditions can fluctuate, altering soil properties. Operator proficiency and survey methodology will also influence GPR findings. Therefore, GPR equipment performance evaluation involves standardized tests that are frequently conducted indoors within laboratory-controlled environments. This study uses outdoor United States Golf Association (USGA) putting greens as a structure for GPR testing for surveying practitioners. These USGA putting greens provide a tightly controlled environment because many golf courses and sports turf fields adhere to strict USGA construction and irrigation guidelines. Past studies on several USGA greens show that GPR provided precise and accurate profiles of root-mixture depth, gravel-blanket thickness, and drain-tile layout. Results are independent of locale, as all USGA putting greens are virtually i...

Ground-Penetrating Radar Water Content Mapping of Golf Course Green Sand Layers

ABSTRACT Information on the spatial distribution of water content across the sand layer component of a golf course green can be important to golf course superintendents for evaluating drainage effectiveness and scheduling irrigation. To estimate the bulk volumetric water content of the sand layer at point locations across the green, a technique was developed that combined (1) depth (or thickness) of the sand layer measured with a steel shaft tile probe, (2) radar signal two-way travel time from the base of the sand layer obtained using a ground-penetrating radar (GPR) system with 900 MHz antennas, and (3) an empirical equation relating porous media dielectric constant to water content. To test this technique, two GPR surveys were conducted on the Nursery Green at the Double Eagle Golf Club near Galena, Ohio, and two additional GPR surveys were carried out on the 9th Hole Green at the Delaware Golf Club near Delaware, Ohio. For comparison, time-domain reflectometry (TDR) water content values for the sand l...

On-Farm Water Recycling as an Adaptation Strategy for Drained Agricultural Land

Agriculture in the Great Lakes region has benefited from precipitation patterns that are fairly regular throughout the year. The beneficial climate, coupled with soils that generally have high water holding abilities, has allowed agriculture in the region to become highly productive and a substantial contributor to the region’s economy. However, predicted shifts in temperature and precipitation patterns towards warmer and wetter winter and spring months, a greater frequency of intense storms throughout the year, and more severe and longer droughts in the summer suggest the potential for decreased crop yields in the future unless ways are found to provide additional water to crops during growing season drought, while also being able to quickly remove excess soil water when conditions are wet.