What is the best drainage system since ancient times?

The Forbidden City, also known as the Forbidden City, is the royal palace of the Ming and Qing Dynasties, formerly known as the Forbidden City, located in the center of the central axis of Beijing, and is the essence of ancient Chinese court architecture. The Forbidden City in Beijing is centered on three halls, covering an area of 720,000 square meters, with a construction area of about10.5 million square meters. There are more than 70 palaces and 9000 houses. It is one of the largest and best-preserved ancient wooden buildings in the world.

The construction of the Forbidden City began in the fourth year of Yongle, the Ming emperor 1406, based on the Forbidden City in Nanjing, and was completed in the eighteenth year of Yongle 1420. It is a rectangular city with a length of 96 1 m from north to south and a width of 753 m from east to west. Surrounded by a wall with a height of 10 meter, there is a moat with a width of 52 meters outside the city.

The Forbidden City has a perfect drainage system, which is still intact after numerous rainstorms and has never been flooded. It turns out that a complete and huge drainage system was born as early as 600 years ago when the Forbidden City was built. Using the geographical characteristics of Beijing, craftsmen can roughly divide it into building drainage, ground drainage, underground culvert and other drainage systems.

When it rains, the water on the roof flows to the ground through the drainage ditch, and part of the water flows into the surrounding stone trough open ditch along the slope of the ground and is collected in the culvert. The underground culvert is nearly 13 km, extending in all directions. The water entering the culvert flows back to the main ditch from the branch ditch, into the Jinshui River, and finally into the moat with a width of 52 meters. It is this perfect drainage system that has kept the Forbidden City from being flooded by rain for more than 600 years. Have you ever been to the Forbidden City? Do you know anything about the architecture of the Forbidden City? Welcome to leave a comment below.