DYNAMIC RESPONSE IN ESTUARIES-AN ANALYTICAL MODEL

A simple analytical model is developed to interview the general features of theestuarine responses induced both by ocean tides and by low-frequency coastal fluctuations andwind forcings.Model estuary is assumed ideally with constant depth and linearly varyingbreadth.The results indicate that the effects of bottom friction coefficient,the water depth andthe breadth variation parameter on the estuarine response field virtually reflect the difference ofthe energy accumulation,transformation and dissipation in estuaries,It is found by comparisonthat there are obvious differences between tidally-induced and low-frequency forcing inducedestuarine variations.For tidal response,bottom friction is a very important factor to affect theresponse magnitude,while for low-frequency response this effect becomes negligible.Thus amore simplified model for low-frequency estuarine response is produced,which gives morestraightforward view to the response characteristics.Moreover,from the model solutions wededuce a general qualification for the estuarine resonance and discuss the relation between theresonance frequency and the estuarine geometry.

DYNAMIC RESPONSE IN ESTUARIES-AN ANALYTICAL MODEL

A simple analytical model is developed to interview the general features of the estuarine responses induced both by ocean tides and by low-frequency coastal fluctuations and wind forcings.Model estuary is assumed ideally with constant depth and linearly varying breadth.The results indicate that the effects of bottom friction coefficient,the water depth and the breadth variation parameter on the estuarine response field virtually reflect the difference of the energy accumulation,transformation and dissipation in estuaries,It is found by comparison that there are obvious differences between tidally-induced and low-frequency forcing induced estuarine variations.For tidal response,bottom friction is a very important factor to affect the response magnitude,while for low-frequency response this effect becomes negligible.Thus a more simplified model for low-frequency estuarine response is produced,which gives more straightforward view to the response characteristics.Moreover,from the model solutions we deduce a general qualification for the estuarine resonance and discuss the relation between the resonance frequency and the estuarine geometry.