Volume transport and estuarine features at Cochin inlet

Abstract

The volume transport of water at Cochin inlet is controlled by tidal range and duration, quantity of fresh and intrusion of saline water. For tides of almost equal duration and range, the volume transport under flood tide during south-west monsoon is comparatively lower and during monsoon higher at ebb tide. The freshwater fraction is slightly higher in Ernakulam channel than Mattanchery channel. Freshwater fraction is very large during south-west monsoon (0.71 in July, 1985) and the least during pre-monsoon (0.22 in March, 1986). The freshwater content increases from September (0.29) to October (0.47) and decreases thereafter. Dilution factor is high (4.00 to 4.55) during pre-monsoon and low during south-west monsoon. Computed values of Stratification-Circulation parameters for Cochin inlet show high values during monsoon. In July and August the estuary can be classified as saltwedge type or highly stratified. In September to January and June partially mixed conditions prevail while during the rest of the months, well mixed conditions exit