- occasional or regular frequency
- attempts to correlate SSC with discharge
obtains actual water samples that can be analyzed in the lab for sediment content
spatial and temporal coverage typically very limited
poor correlation of discharge to SSC
obtaining samples can be dangerous and is costly (labor)
can miss >90% of information
- automated sampler with simple programming to grab water samples at timed intervals
- stage sensor or turbidity sensor for continuous measurement of threshold trigger
obtains water samples and continuous turbidity measurement
low probability of samples taken in storm events (when turbidity is high)
frequent site visits required to obtain samples and reset sampler — costly
high water analysis cost, yet little valuable information
poor correlation to SSC
- sensors and datalogger deployed full-time in-situ
- one or multiple parameters are continually measured and recorded
low cost after equipment purchased—no manual samples needed
better temporal coverage than grab sampling
without water samples taken, cannot establish correlation to SSC
The Evolution of Sediment Monitoring
- automated sampler triggered by rising and falling turbidity thresholds measured by instream turbidity sensor through a programmed datalogger
obtains water samples and continuous turbidity measurement
samples obtained all provide useful information—no over or under sampling
lab handling costs kept to minimum
site visits needed only when all sample bottles are full—labor costs kept to minimum