Mixing enhancement mechanisms in aquifers affected by hydropeaking: Insights from flow-through laboratory experiments
In this study, we performed flow-through experiments to investigate transport processes in a laboratory setup mimicking an aquifer affected by hydropeaking. We performed five flow-through experiments: steady flow experiment, steady flow experiment with river system by keeping the head of both rivers equal to the groundwater table, and finally three transient flow experiments (that will be described in the texts as transient flow 1, transient flow 2 and transient flow 3) considering two time series of fluctuating river heads. We performed high-resolution image analysis, and depth-resolved, high-frequency sampling at the outlet of the flow-through chamber to monitor the evolution and the breakthrough of the tracer plume in the porous medium. The dataset contains: 1. The tracer concentration normalized by the initial concentration at the outlet of the flow-through chamber obtained from the optical analysis for the five experiments. 2. The tracer concentration normalized by the initial concentration obtained from the spectrophotometric analysis of the samples collected at the outlet of the flow-through chamber for the five experiments. 3. The results of the second central spatial moments of the solute distribution (cm2), dilution index (cm3) and flux-related dilution index (cm3/min) for the five experiments.