(
2016-12)
Kearney, William S.; Mariotti, Giulio; Deegan, Linda A.; Fagherazzi, Sergio
Long-term records of the flow of water through tidal channels are essential to constrain
the budgets of sediments and biogeochemical compounds in salt marshes. Statistical
models which relate discharge to water level allow the estimation of such records from
more easily obtained records of water stage in the channel. Here we compare four
different types of stage-discharge models, each of which captures different characteristics
of the stage-discharge relationship. We estimate and validate each of these models on a
two-month long time series of stage and discharge obtained with an Acoustic Doppler
Current Profiler in a salt marsh channel. We find that the best performance is obtained by
models that account for the nonlinear and time-varying nature of the stage-discharge
relationship. Good performance can also be obtained from a simplified version of these
models, which captures nonlinearity and nonstationarity without the complexity of the
fully nonlinear or time-varying models.
