A pool-riffle-pool sequence is a nearly ubiquitous element of stream bed morphology. The variabiltiy in bed elevation is thought to allow surface water to infiltrate through the stream bed the head of a riffle and upwell back to the stream at the tail of the riffle in a pool-riffle-pool (PRP) sequence, thus driving a surface water-ground water interaction termed hyporheic exchange. Because infiltrating surface water transports heat from daily heating and cooling; Heat tracing within the streambed sediments is a potentially useful method to characterize hyporheic exchange. For this purpose, temperature was monitored within a PRP sequence for several days at Jaramillo Creek in the Valles Caldera National Preserve. Temperature in the hyporheic zone below the pool-riffle-pool sequence reflected the diel temperature change in Jaramillo Creek but not uniformly. The observed thermal pattern exhibited deeper penetration of thermal oscillations below the head pool and shallower penetration below the tail pool. Play the video below to watch diel cycles of temperature change in sediments below a pool-riffle-pool sequence:
To learn more about one-dimensional analytical heat transport (tracing) models that can use such temperature information to estimate the exchange of water between streams and their associated aquifers, check out the manuscript by clicking on the image at the top of this blog post.