On this day 109 years ago, on January 14, 1916 (December 10, 1915 lunar calendar), the Zude Sea Dam in the Netherlands collapsed, causing flooding. The Zude Sea region is located in the north-central part of the Netherlands. In 1916, the Dutch government began to build a dam to isolate the Zude Sea from the North Sea in an attempt to drain the water in the Zude Sea area and develop the area into an agricultural area. On January 14, 1916, the Zude Sea Dam in the Netherlands collapsed, causing flooding. In order to survive and develop, the Dutch tried their best to protect their originally small territory from "annihilation" when the sea was at high tide. They fought against the sea for a long time and reclaimed land from the sea. As early as the 13th century, they built dikes to block the sea, and then used wind-driven water trucks to drain the water in the cofferdam. For hundreds of years, the Netherlands has built 1,800 kilometers of sea-blocking dams, increasing the land area by more than 600,000 hectares. In the late 1920s and early 1930s, the Dutch implemented the world-renowned Zuider Sea Project and the Delta Project. It took six years to build a 32-kilometer-long sea-blocking dam, which cut the Zuider Sea from the North Sea and turned it into a lake. Since the river water has to pass through this lake to enter the sea, and the seawater is constantly desalinated, the Zuider Sea has gradually become a freshwater lake and finally transformed into land. The last dam of the Delta Project was completed in 1986. The whole project took more than half a century to connect several islands, close several river estuaries, and successfully keep seawater out of the country. Today, 20% of the Dutch land is artificially reclaimed.