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The Thames Estuary is the estuary in which the River Thames meets the waters of the North Sea. It is not easy to define the limits of the estuary.〔(【引用サイトリンク】title=81. Greater Thames Estuary )〕 Although physically the head of ''Sea Reach'' or the ''Kent/Essex Strait'', south of Canvey Island on the northern (Essex) shore presents a western boundary, the Tideway itself can be considered estuarine; it starts in south-west London at Teddington/Ham. The eastern boundary of the estuary suggested in a Hydrological Survey of 1882-9 is a line drawn from North Foreland, Margate, Kent via the ''Kentish Knock lighthouse'' to Harwich in Essex. It is to this line that the typical estuarine sandbanks extend.〔(【引用サイトリンク】title=Thames Estuary Passages )〕 The estuary downstream of the Tideway has a tidal movement of 4 metres, moving at a speed of 8 miles per hour. The estuary is one of the largest of 170 such inlets on the coast of Great Britain. It constitutes a major shipping route: its thousands of movements each year include large oil tankers, container ships, bulk carriers and roll-on/roll-off (ro-ro) ferries entering the estuary for the Port of London and the Medway Ports of Sheerness, Chatham and Thamesport. The traditional Thames sailing barge worked in this area, designed to be suitable for the shallow waters in the smaller ports. More recently one of the largest wind farms in the UK has been developed in the estuary, located 8.5 km north of Herne Bay, Kent. The farm contains 30 wind turbines generating a total of 82.4MW of electricity. The much larger London Array of up to 1GW capacity is also planned. This area has had several proposed sites for the building of a new airport to supplement, or even to replace Heathrow/Gatwick. In the 1960s Maplin Sands was a contender; in 2002 it was to be at Cliffe, Kent. The new airport would be built on a man-made island in the estuary north of Minster-in-Sheppey There is also some discussion about the need for a Lower Thames Crossing in order to alleviate traffic congestion at Dartford. The Thames Estuary is the focal part of the 21st-century toponym, the "Thames Gateway", designated as one of the principal development areas in Southern England. ==Greater Thames Estuary== The appellation Greater Thames Estuary applies to the coast and the low-lying lands bordering the estuary itself. These are characterised by the presence of mudflats, low-lying open beaches and salt marshes, namely the North Kent Marshes and the Essex Marshes. Man-made embankments are backed by reclaimed wetland grazing areas, but Rising sea levels may make it necessary to temporarily flood some of that land in places at spring tides, to take the pressure off the defences. There are many smaller estuaries in Essex, including the Rivers Colne, Blackwater and Crouch Small coastal villages depend on an economy of fishing, boat-building, and yachting. The Isle of Sheppey, Foulness Island and Mersea Island are part of the coastline Where higher land reaches the coast there are some larger settlements, such as Clacton-on-Sea to the north in Essex, Herne Bay, Kent, and the Southend-on-Sea area within the narrower part of the estuary 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Thames Estuary」の詳細全文を読む スポンサード リンク
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