Tianjin/ The Vanish of Transportation Function of Hai River in Tianjin City -part1
The identity of Hai River change from a water transportation routine to a natural, public, and communal landscape. Two sluice gates are to be mentioned.
（1） The First Gate
Hai River is a tidal river, which means the sea water may flush back into the river channel by tide force if there isn’t enough fresh water coming down from the land. The phenomenon caused huge problems because the salt water is neither drinkable nor suitable for irritation. So in 1958 the government make a big decision which generally cause the vanish of the river channel’s transportation function: Build a sluice gate to stop the sea water from the fresh.
The Tide-resist Gate proposal was quickly approved and the project was completed in 181 days by professionals and over a million volunteering citizens. The gate located at the outlet of the Hai River and achieved the goal to stop the sea water but it also stop the sand and soil on the other side. Without the natural tide force, deposition quickly reduced the depth of the channel and the transportation function is weakened. As the population of Tianjin grow and the declination of the coming water from the origin, a new sluice gate becomes inevitable.
(2) The Second Gate
In 1984, the new project, which is called the secondary sluice gate is approved. It is designed 39.5km before the Tide-resist Gate. The idea of it is to “ Keep fresh water within upstream and Keep transportation within down stream 上游保水，下游保航”. In other words, the sector between the Secondary Gate and the Tide-resist Gate will be filled with sea water.
After the completion of the Secondary Gate, the original farmland (39.5 km) in downstream suffered for salt water but the people lived in the downtown are blessed with enough fresh water. The Secondary Gate becomes a critical geographical boundary between fresh water and salt water, which I think influences the zoning of urban development later on. What’s more, the original river channels in Tianjin city ( 29.3km) before the Secondary Gate completely lost its function as water transportation routine, which led to abandon of the old industrials in the city.
The infrastructure people built on Hai River for better urban living conditions radically change the situation of the river and then it influences the urban conditions we lived in return to which we have to respond. The sector of the river in Tianjin city stayed as a simple river for a while until it became an issue again in 2002, the year after the successful bid of Beijing Olympic Games.