Estuary Formation:

Most estuaries can be grouped into four geomorphic categories based on the physical processes responsible for their formation:

(1) rising sea level; (2) movement of sand and sandbars; (3) glacial processes; and (4) tectonic processes.

♤ Estuaries are typically classified by their geomorphological features or by water circulation patterns and can be referred to by many different names, such as bays, harbors, lagoons, inlets, etc.

♤ The banks of estuarine channels form a favoured location for human settlements, which use the estuaries for fishing and commerce, but nowadays also for dumping civic and industrial waste.

♤ Estuaries are usually biologically highly productive zones.

♤ They also act as a filter for some dissolved constituents in river water; these precipitate in the zone where river water meets seawater.

♤ More important is the trapping of suspended mud and sand carried by rivers which leads to delta formations around estuaries.