North Carolina State University
Co-Authors: C. Sayde and B. Doll
The need to construct resilient water ways is of growing importance in the face of extreme weather events and environmental degradation. However, the groundwater dynamics of systems, especially regenerative storm water conveyance systems (RSC), are not yet fully understood. Through technological advancements, the precision and availability of tools for monitoring in-situ parameters have increased dramatically. However, an accurate method for determining water fluxes through retention systems continues to be uncertain and challenging. By deploying a fiber optic system in a regenerative storm water conveyance structure, we hope to uncover the behavior of subsurface water flow and make better predictions of the expected treatment an RSC may offer.
Although methods like multi-needle heat pulse approaches have demonstrated the ability to make point measurements of water fluxes in the vadose zone, these offer limited viability in the field due to their minuscule sphere of influence and the need to understand flux densities behavior over large spatial scales. By utilizing the properties of optical fibers, we intend to improve this long-standing limitation by instead taking hundreds of simultaneous distributed measurements through an RSC.
The results from the existing body of work on this topic show high potential for optical fibers uses in applications under field conditions; however, many challenges remain. Deployment of pulse heated fiber optics requires precise spacing between cables and auspicious georeferencing. Despite these challenges, the long-sought-after ability to accurately measure water flux density would give hydrologists, engineers, and land managers a valuable tool to better understand the processes of infiltration, runoff, and subsurface treatment.