Abstract:

The hyporheic region of rivers and streams is of great ecological importance.  In this region, nutrients undergo oxic and anoxic reactions, pollutants deposit, and many other biogeochemical processes take place.  Hyporheic flow is affected by numerous factors including: surface water flow, topographical bed characteristics, and sediment properties.  In this talk, I will focus on three highly visual experiments and their associated spatial models that seek to reproduce the patterns that these visualizations demonstrate.  The first experiment uses dye to track water flow through homogeneous bedforms in a predominantly two-dimensional flume.  The second experiment follows dye through a grid composed of two sediments whose hydraulic conductivity values differ by more than an order of magnitude.  The third experiment investigates the transport, deposition, and resuspension of fluorescent pink fine particles between surface water and sediments in an immobile homogeneous sand system.  Each system tracks individual particles through a region of approximated head values with varying degrees of success. Creating visual simulations to accompany the experiments provides both a quantitative and a qualitative illustration of the simulations’ ability to replicate the experimental data.  My goal in creating and disseminating these visualizations and simulations is that they will improve conceptual comprehension of the phenomena under study.

Author: Susa Stonedahl

Affiliation: Engineering and Physics Department, St. Ambrose University, Davenport, IA, USA