High-resolution lake infill time modeling at Jackson Lake, Wyoming (USA)

With growing climatic, anthropogenic, and environmental pressures on lakes and reservoirs globally, accurate quantitative sediment infilling estimates, or lake/reservoir lifespans, are essential to the effective management of these systems. Current methods used to model lake and reservoir infill timescales are limited in scope. This study presents refined data-rich infill models of Jackson Lake, Wyoming (USA). Basin-wide seismic reflection profiles were used to obtain lake volume and total sediment isopach measurements. Radionuclide-dated sediment cores were collected to capture variability in sedimentation patterns, partly because of the lake’s bathymetric complexity. Three infill models were produced, including: (1) a model that uses radionuclide-based sedimentation rates and a 1-D linear infill, (2) a model that uses radionuclide-based sedimentation rates and a 3-D mass-based infill, and (3) a model that relies on sediment volume calculations and assumptions of basin age only. A fill-and-spill approach was utilized to ensure conservation of mass through each time step. All 3 models exhibited strong agreement on an infilling time of ∼30 000 years from present. Models developed in this study emphasize the need to accurately determine lake volumes and capture basin-wide complexity in sedimentation patterns, both of which are commonly poorly resolved in similar studies. Further development of data-rich lake/reservoir infill models could greatly benefit global lake and reservoir research critical to understanding engineered reservoir lifespans and carbon cycling in these systems. Further, accurate infilling data can assist in the development and application of effective policies for freshwater resource management and conservation, promoting the long-term sustainability of lake/reservoir systems.