"Foot-washed" by the flood is still intact. Where is the cow in the Leshan Giant Buddha Millennium Drainage System?

　　In late August, affected by the flood conditions, the Leshan Giant Buddha, located at the confluence of the Three Rivers in Sichuan, was flooded to toes for the first time in 70 years, but it did not affect the main body of the Leshan Giant Buddha, which has a history of more than 1,300 years.

Some netizens pointed out that the drainage system of Leshan Giant Buddha has played a key role in protection.

　　So how does the drainage system protect the Leshan Giant Buddha?

Many cultural relics were damaged by floods this summer. What's the trick behind the Leshan Giant Buddha's 1,000-year-old failure?

In order to find answers, on September 10, a reporter from Science and Technology Daily interviewed relevant experts.

What is unique in the body of the Buddha

　　The Leshan Giant Buddha, also known as the Lingyun Giant Buddha, is located on the side of Lingyun Temple on the east bank of the Nanmin River in Leshan City, Sichuan Province, close to the confluence of the Dadu River, Qingyi River and Minjiang River.

Leshan belongs to the mid-subtropical humid climate zone, with many rainfall days and high rainfall intensity. The annual average rainfall in the Leshan Giant Buddha area is 1368 mm.

　　According to incomplete statistics from the State Administration of Cultural Heritage, as of July 16, more than 500 immovable cultural relics across the country have been damaged to varying degrees due to floods this year.

Among them, there are many national and provincial key cultural relics with a long history and unique value.

　　"The damage caused by the heavy rainfall to the Leshan Giant Buddha is still relatively low." Sun Bo, deputy director of the Cultural Protection Center of the Northwest Institute of China Railway Research Institute, explained that due to the complete drainage system of the Leshan Giant Buddha, the toes of the Giant Buddha were flooded this time. It's just that the additional layer of cement mortar has fallen off the sitting platform under the Buddha's feet. Strictly speaking, it is not that the cultural relic itself has been damaged.

　　So what is the ingenious design of the drainage system of Leshan Giant Buddha?

　　"In order to prevent rainwater from eroding the Buddha, the ancient craftsmen carefully designed the drainage system when excavating the Leshan Giant Buddha." Sun Bo said that the drainage system is divided into two parts: the guidance of the groundwater of the Buddha body and the drainage of the surface water of the Buddha body. Solve the problem of different sources of water.

　　When you stand on Lingyun Temple and look towards the head of the Buddha, you will see that all the buddha's hair buns are in a spiral shape, so they are also called "snail buns", which are made of stone blocks one by one. Yes, there are 1051 in total, neatly arranged 18 floors.

　　The reporter learned that among the 18 layers of snails on the head of the Buddha, there is a horizontal drainage ditch on the 4th, 9th and 18th layers; there are caves on the back of the two ears that communicate with each other on the left and right sides of the chest. Each has a hole, but they are not cut through each other. These ditches and caves form a scientific drainage, moisture isolation and ventilation system in the "body" of the Buddha to prevent it from being corroded and weathered.

　　"There are folds made of beating ash on the neck and collar of the Great Buddha. One is for decoration, and the other is for drainage. On the folds, ancient craftsmen set up some small drainage grooves to drain the water smoothly. ."He says.

　　In addition, as part of the drain, the drain on the chest is actually the robes of the Great Buddha. Ancient craftsmen combined carving and drainage, so that the surface water and seeping groundwater from the upper body of the Great Buddha were introduced into the drain on the right abdomen, thus forming a complete set Drainage system, and directly into the Minjiang River through the outside of the right foot of the Buddha.

Waterproof design has "something else"

　　The Leshan Giant Buddha is a seated Maitreya Buddha with a height of 71 meters. It is the largest carved stone statue on a cliff in China.

Sun Bo said that after the completion of the Leshan Giant Buddha, an annex building-the "Large Elephant Pavilion" was built, which was the first building to "shield the wind and rain" for the Buddha.

　　Under normal circumstances, tourists have no impression of the cover of this giant Buddha.

"This wooden structure of the Great Elephant Pavilion has been destroyed. The date of the destruction is unknown. Some said it was the Yuan Dynasty, and some said it was at the end." Sun Bo said.

　　It is well documented that in history, the cover of Leshan Giant Buddha was built and destroyed.

Su Shi once mentioned in his poem "Looking down at the Lingyun Pavilion of the Ancient Buddha".

Sun Bo said that in addition to the existing drainage system, the Great Elephant Pavilion was also used as a cover for the main body of the Great Buddha, which can prevent the Great Buddha from being damaged by rain.

　　The Leshan Giant Buddha was excavated in the wild, exposed to the sun and rain for thousands of years, why can it continue to the present?

　　In order to protect the Buddha statues, the ancients knew the need to solve the rainfall problem caused by the weather, so they built the Great Elephant Pavilion to waterproof it.

“Due to the high humidity of the air at the location of the Leshan Giant Buddha, the surface of the Giant Buddha is prone to condensation, causing plant moss to invade.” Sun Bo said that the existence of the Big Elephant Pavilion not only solves the problem of rainfall, it also avoids the erosion and erosion of the Giant Buddha by the water of the Minjiang River. The influence of the humidity of the surrounding air can explain why the Big Buddha is now being eroded by wind at a rapid rate, mainly because there is no shelter after the Great Elephant Pavilion was destroyed.

　　Sun Bo told reporters that the rocks that make up the Leshan Giant Buddha itself are mainly white red sandstone, which is relatively strong.

"The land chosen by the ancients is composed of huge thick layers of rock, with relatively few broken zones, and relatively complete rock mass." When the ancient craftsmen designed the Leshan Giant Buddha, they reflected its climate, site selection and exquisite craftsmanship. scientific.

　　Li Di reporter Shengli