Assessing sinkhole hazard at the blue and white golf course, state college, using a combined remote-sensing and field methods approach

Abstract Sinkholes are a common problem faced by golf courses throughout the U.S. due to the large amount of water cycled through and transported beneath them by natural and anthropogenic means. In State College Pennsylvania, the Blue and White Golf Course has experienced sinkholes around the course including a large one by the Blue Course’s Hole 15 in the mid 2000s. Using multi-spectral optical data (Landsat 8/9) and Interferometric Synthetic Aperture Radar (InSAR) spanning 2017–2025, this work explores soil moisture and ground motion across the golf course through time and space. In addition to these measurements, pore water samples are taken at different points across the golf course to measure pH and conductivity. The multi-spectral data show the golf course has a higher than average NDMI than the surrounding area, with high values (> 0.15) along fairways for the different holes, while the average velocity map from the InSAR, validated with available GNSS data, shows subsidence across the golf course that heightens to values > 1 cm/yr in the south/southwest region of the Blue Course. Geochemical analysis of the field samples shows that the pH of the golf course pore water is slightly more acidic than control sites, suggesting that dissolution is likely occurring beneath the golf course. Combining these datasets with regional rainfall, local elevation, and previous karst feature data show local features combined with course maintenance have stronger influence over subsidence rates and hydrologic mechanisms (dissolution, infiltration) than regional controls.