Turning Lakes Into River Gauges Using the LakeFlow Algorithm

• Published in: Geophysical research letters 2023-05, Vol.50 (10), p.n/a
• Main Authors: Riggs, Ryan M., Allen, George H., Brinkerhoff, Craig B., Sikder, Md. Safat, Wang, Jida
• Format: Article
• Language: English
• Subjects: Algorithms; Conservation; Estimates; Evaporation; Evaporation data; Gauges; Hydrology; Inflow; Interfaces; Lake evaporation; Lake hydrology; Lake inflow; lake storage change; Lakes; Mass balance; Outflow; Remote sensing; remote sensing of discharge; Reservoirs; Resource management; River discharge; River flow; Rivers; river‐lake dynamics; Satellite observation; Satellites; Stream flow; Surface water; SWOT satellite; Synthetic data; Water discharge; Water inflow; Water management; Water outflow; Water resources; Water resources management
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2023GL103924

Rivers and lakes are intrinsically connected waterbodies yet they are rarely used to hydrologically constrain one another with remote sensing. Here we begin to bridge the gap between river and lake hydrology with the introduction of the LakeFlow algorithm. LakeFlow uses river‐lake mass conservation and observations from the Surface Water and Ocean Topography (SWOT) satellite to provide river discharge estimates of lake and reservoir inflows and outflows. We test LakeFlow performance at three lakes using a synthetic SWOT data set assuming the maximum measurement errors defined by the mission science requirements, and we include modeled lateral inflow and lake evaporation data to further constrain the mass balance. We find that LakeFlow produces promising discharge estimates (median Nash‐Sutcliffe efficiency = 0.88, relative bias = 14%). LakeFlow can inform water resources management by providing global lake inflow and outflow estimates, highlighting a path for recognizing rivers and lakes as an interconnected system. Plain Language Summary Effective water resource management depends on our ability to monitor and understand lake and reservoir inflows and outflows. Satellite remote sensing of lakes and rivers has become increasingly important for water management but little work has been done to estimate streamflow at river‐lake interfaces. Here we present the LakeFlow algorithm that leverages satellite observations of lakes and rivers to estimate streamflow at lake inflows and outflows. We test LakeFlow using synthetic data at three U.S. lakes in Georgia, Arizona and Kansas, and find that it yields promising estimates of streamflow at river‐lake boundaries. LakeFlow provides valuable insights into river‐lake streamflow dynamics, which can inform water management decisions and is a step forward in the integration of river and lake studies. Key Points LakeFlow is a new algorithm that uses Surface Water and Ocean Topography (SWOT) satellite data to estimate river inflow and outflow at lakes via mass conservation Applying LakeFlow to three sample lake systems shows promising performance for estimating lake inflows and outflows (median Nash‐Sutcliffe Efficiency = 0.88) Including modeled estimates of non SWOT‐observed evaporation and tributary inflows can further improve LakeFlow discharge estimates