Two-zone transient storage modeling using temperature and solute data with multiobjective calibration: 2. Temperature and Solute

摘要

This paper presents the multiobjective calibration results for temperature and solutefrom a two‐zone temperature and solute (TZTS) model which separates transient storageinto surface (STS) and subsurface (HTS) transient storage components. This modelcontains terms associated with surface heat fluxes in the main channel (MC) and STS, heatand mass exchange between the STS and MC, heat and mass exchange between the HTSand MC, and heat exchange due to bed and deeper ground conduction. To estimate theadditional parameters associated with a multiple‐zone model, a data collection effort wasconducted to provide temperature time series and solute tracer curves representingthe movement of heat and/or solute through each zone. A multiobjective calibrationalgorithm was linked to the TZTS model to assist in parameter estimation and to provideinformation about parameter uncertainty and tradeoffs associated with matchingdifferent combinations of observations (e.g., solute and/or temperature data gathered invarious zones). Results generated from three different combinations of calibration dataillustrated that the two‐zone model accurately reproduces temperatures and tracerconcentrations observed in different zones when considered independently. However,there were many parameter sets that resulted in objectively indistinguishable results. Whentracer and temperature observations were considered simultaneously in model calibration,the simplistic representation of the surface and subsurface zones did not adequatelyreproduce both observation types in each zone. If the uncertainty in model parametersand the data are taken into account, however, the results of the study suggest that it isplausible to use temperature and tracer information simultaneously to better informtransient storage modeling approaches.