By this definition, a tidal river will be affected by tides, surges, and sea level variation, though its water may not have a high salinity content.
[2] Areas of brackish water seaward of the tidal river section are often called estuaries.
[4] Discharge estimates from freshwater tidal rivers are important for informing water resource management and climate analyses.
[3] Some challenges to estimating discharge amounts include reversing tidal flow, compensation flow for Stokes drift, spring-neap water storage effects, lateral circulation, and multiple distributaries or ebb and flood channels.
[5] The Rio de la Plata is a tidal river on the border between Uruguay and Argentina.
[7] During low-flow periods, this river's tidal area may extend over 1,000 km into the Amazon depression.
For major rivers, such as the Saint Lawrence River (and the associated Saint Lawrence Seaway), publications such as an atlas of surface currents (or tidal currents) may be available, based on sophisticated hydrodynamic models, subject to empirical validation.