Datasets of Radwin 2023 Great Salt Lake Remote Sensing Historical Assessment

Included are the culminated datasets for an article which is in the process of being submitted to the Utah Geological Association. This data helps an investigator reproduce or utilize the data. There are datasets for both Landsat and Sentinel, for both the North and South arms of the Great Salt Lake. Additionally, there are datasets documenting the NDWI threshold used for each Landsat image, the outlier images not used in analyses, NDWI error assessment, and calculation of stats/facts. Paper abstract: The Great Salt Lake has been rapidly shrinking since the highstand of the mid-1980’s, creating cause for concern in recent decades as the lake has reached historic lows. Many investigators have assessed the evolution of lake elevation, geochemistry, anthropogenic impacts, and links to climate and atmospheric processes, however, the use of remote sensing to study the evolution of the lake has been significantly limited. Harnessing recent advancements in cloud-processing, specifically, Google Earth Engine cloud computing, this study utilizes over 600 Landsat TM/OLI and Sentinel MSI satellite images from 1984-2023 to present time-series analyses of remotely sensed Great Salt Lake water area, shoreland area, surface cover types, and chlorophyll-a analyses paired with modelled estimates for water and shoreland area. Results show that since the highstand of 1986, the water area has declined by 50% (~2,400 km²) and the shoreland area has increased to ~2,600 km² from ~200 km². The area of unconsolidated sediments not protected by vegetation or halite crusts has risen to ~2,200 km². Significant halite crusts are observed in the North Arm, having a max extent of ~150 km² between 2002 and 2003, while only small extents of halite crusts are observed for the South Arm. Vegetation is more prevalent in the South Arm and its area has increased by over 400% since 1990. Gypsum is widely observed independent of halite crusts. The results highlight multiple instances of land-use that led to observable changes in water/shoreland area and halite crust extent. This study demonstrates the important benefits of maintaining a lake elevation above ~4,194 ft to maximize lake and halite crust area, which would help mitigate possible dust events and maintain broad lake extent.