Hydrologist
U.S. Geological Survey
Bio:
Scott Hynek has worked on the geology and hydrology of closed basins in Central Asia, East Africa, South America, and North America. Of particular interest is the genesis of brines in the Americas. Recent work addresses the linkages between water quantity, water quality, and shorebird ecology throughout the Great Basin.
Title: Getting to Know the Invisible Sweaty Giant of Great Salt Lake
Abstract: Evaporation from terminal lakes in the Bonneville Basin is a critical control on lake level, lake area, and lake volume. Recent work by colleagues demonstrated that high lake levels of Lake Bonneville between approximately 21,000 and 15,000 years ago were driven mostly by depressed temperatures (7–9.5°C cooler) augmented by minor increases in precipitation (7–21%). Positing that the converse may also be true: increasing temperature will be the primary driver of increasingly lower Great Salt Lake elevations; we embarked on a collaborative effort to combine monitoring and modeling of Great Salt Lake (GSL) volumes. Data collected by the USGS Utah Water Science Center was used to conduct a volume balance analysis using lake volumes and inflow volumes at monthly timesteps. These data were used to calibrate a suite of open water evaporative models using a variety of gridded climatic datasets over the period 2007–2015. These models were then validated over the period 2016–2022. The best model results indicate average monthly evaporative losses have an absolute mean error of ~40,000 acre-feet (~10%), with a slight underprediction (mean bias error) of 8,000–6,000 acre-feet per month (roughly 2–4%). To maintain a lake level of 4196.2 feet (NGVD 1929) it is estimated that 2.9 million acre-feet per year of inflow is required. Under a 4°C warming scenario an additional 400,000 acre-feet of water is required (3.3 million acre-feet total) to maintain the same lake level.
