How did the Dutch reclamation dam come into being? What does this mean?

Zuider zee used to be an inland bay. The coastline in the bay is 300 kilometers long and the mouth of the bay is only 30 kilometers wide. 1932, the Dutch built a seawall with a width of 90 meters and a height of 7 meters above the sea surface, separating Sude Bay from the North Ocean. Since then, the seawater in the bay has been continuously pumped out, and by 1980, 260,000 hectares (2,600 square kilometers) have been built.

It shows that human beings can transform nature, and the Netherlands has been fighting against the sea. After centuries of efforts, the total length of the dam has reached 1800 km, and 700,000 hectares of land have been reclaimed from the sea.

Extended data:

Low level is the most prominent feature of Dutch terrain. The whole territory is low-lying, with a quarter of the land below the altitude 1 m and a quarter below the altitude. Except for some hills in the south and east, most of the terrain is very low. The south is connected by the Rhine, Maas and Guerder River Delta.

"Holland" is called Holland in Germanic language, which means "the land of lowlands". It got its name because more than half of its land is below or almost at sea level, and some areas are even formed by reclamation, such as most parts of Frevoland Province.

The highest point in the Netherlands is Vaalserberg, which is located in the southeast corner of Limburg province in the south, with an altitude of 32 1 m. The lowest point in the Netherlands is near Rotterdam, 6.7 meters below sea level.

Baidu encyclopedia-Dutch seawall