Why is there no water in the Forbidden City when it rains heavily in Beijing?

Recently, there have been heavy rains all over the country, and floods have occurred in many places. The situation is not very serious, and there will be different degrees of water accumulation. As for Beijing, our capital, it is also raining constantly. There is water in many places in Beijing, but there is no water in the Forbidden City. Why? Secondly, the drainage system of the Forbidden City has experienced more than 600 years, and its design is exemplary and breathtaking. Everyone should have heard of dragons spitting water. There are 1 142 taps on the triple platform of the Forbidden City, which can drain water through the terrain with high north and low south. On July 20, the drainage stone faucet of the abutment of the three main halls in the central axis was spitting water to drain the rainwater from the abutment. On July 20th, rainwater was discharged into Neijinshui River through the ditch in the Hall of Supreme Harmony Square. The rainwater injected into the Jinshui River did not flood the top of the stone bridge culvert, and the culvert can ensure the open ditch to be smooth.

The drainage system of the 600-year-old Forbidden City is very helpful. Under the heavy precipitation in Beijing, there was no water in the Forbidden City. There are many and dense buildings in the Forbidden City, and the roads are mostly paved with bricks and stones. There was no obvious water accumulation in the palace during the heavy rain, which benefited from the perfect drainage system. According to experts from the Ancient Buildings Department of the Forbidden City, the drainage system of the Forbidden City is divided into three categories, namely, buildings, surface runoff and underground culverts.

The water in the Forbidden City will flow along the open ditch to the mouth of the culvert, and part of it will directly form surface runoff and flow to the culvert, and finally it will be discharged from the Forbidden City through the Neijinshui River. Due to the terrain of the Forbidden City, accumulated water can be drained. According to experts, the horizontal elevation of Shenwumen in the north gate of the Forbidden City is 46.05 meters, and that of Wumen in the south gate is 44.28 meters, with a height difference of nearly 2 meters. This slope creates favorable conditions for natural drainage. Miyagi has designed and built a huge artificial drainage network with criss-crossing, clear primary and secondary, and light and dark combination, including main canals, branch lines, culverts, gullies and many other drainage facilities. ?

Take the former three pavilions as an example. The Hall of Supreme Harmony, the Hall of Zhonghe and the Hall of Baohe are located on the three-storey platform. At the bottom of the railing around the platform, there are drainage holes. There is also a beautifully carved stone faucet under each sentry, and its mouth is a round hole drilled and a drainage hole. The rain fell layer by layer, leaving no water on the table.