The purpose of this study was to determine if individual runoff events could affect intergravel flow in salmon
nests and to investigate the sensitivity of interstitial flow to the fines content and conductivity of the redd patch.
During the summer and autumn of 2001, a new intergravel velocity sensor based on the hot wire principle made it possible to
continuously monitor, over five months, interstitial velocities in artificial redds in four tributaries of the Cascapedia River,
Quebec. Fifteen low and moderate intensity runoff events (up to 50% bankfull) were monitored. It was found that redd interstitial velocities were reduced whenever a runoff event deposited more than 7 kg/m^2 of sands in infiltration traps. In addition, redd interstitial velocities were reduced four out of the five times that the event-integrated suspended sediment dose exceeded 7 mg l^-1 day (dose is defined as the area under the concentration time curve).
The purpose of this study was to determine if individual runoff events could affect intergravel flow in salmon nests and to investigate the sensitivity of interstitial flow to the fines content and conductivity of the redd patch. During the summer and autumn of 2001, a new intergravel velocity sensor based on the hot wire principle made it possible to continuously monitor, over five months, interstitial velocities in artificial redds in four tributaries of the Cascapedia River, Quebec. Fifteen low and moderate intensity runoff events (up to 50% bankfull) were monitored. It was found that redd interstitial velocities were reduced whenever a runoff event deposited more than 7 kg/m^2 of sands in infiltration traps. In addition, redd interstitial velocities were reduced four out of the five times that the event-integrated suspended sediment dose exceeded 7 mg l^-1 day (dose is defined as the area under the concentration time curve).