120-2 Using InSAR to analyze subsidence and sinkage in the Blue & White Golf Course

Session: Land Surface Subsidence: Processes, Impacts, and Ongoing Challenges

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Across the Blue and White Golf Course, data from the spaceborne radar satellite Sentinel-1 revealed that previously unseen long-term deformation in the southern portion of the golf course. As urban development continues to expand in the changing climate, it is important to understand how surface and subsurface processes impact man-made structures Using Interferometric Synthetic Aperture Radar (InSAR) timeseries over the golf course spanning 2014-2025, we identified several small regions of subsidence with rates reaching 1.5 cm/yr. To determine potential causes of these subsidence regions across the golf course, we use multi-spectral optical imagery from Landsat-8 to calculate the Normalized Differenced Moisture Index (NDMI) that can track properties like soil moisture over time. We compare the time series of NDMI with the InSAR time series to determine if changes in soil moisture impact the observed ground subsidence. We then tested geochemical and weathering effects on the sediments in the subsurface of the golf course, which may be a factor of the sinkage that is occurring. Preliminary results indicate that a large proportion of tested water samples are slightly acidic (pH<6.7) which could contribute to the dissolution of the underlying limestone sediments. The results show our processing analysis on pH levels, underlying water flows and the precipitation in that region that is receiving. This research contributes to a more understanding of the sinkage problem on the golf course and potentially find alternatives in the near future in hidden hazardous locations.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

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