, Beijing, February 6 (Reporter Sun Zifa) How did the ancestors of Liangzhu ancient city in China consider water conservancy factors when choosing a site to build a city 5,300 years ago?

How do they build water conservancy projects according to local conditions?

For more than three years since it was listed on the World Heritage List, the research on water control of the Liangzhu Ancient City Site has attracted widespread attention from the academic circles and society.

  As the first archaeological expert to propose and study the water conservancy project outside the ancient city of Liangzhu, Liu Jianguo, a researcher at the Institute of Archeology of the Chinese Academy of Social Sciences, led a team that has focused on the water conservancy project of the ancient city of Liangzhu for a long time and continued to carry out research.

In an interview with a reporter from China News Agency in Beijing recently, he revealed that the latest research using geographic information system spatial analysis and other technologies shows that on the basis of choosing the best location to build the city site to effectively avoid the threat of floods in the rainy season, the ancestors of the ancient city of Liangzhu passed the minimum The principle of intervention maximizes the function of water control, promotes the advantages and eliminates the disadvantages, and makes the best use of the situation to build a set of water conservancy projects that shine through the history, which promotes the birth and development of the Liangzhu civilization.

  Liangzhu ancestors carefully selected the best city building sites

  Liu Jianguo said that the Liangzhu ancient city site is adjacent to the Dongtiao River, the largest river in northern Zhejiang Province, and the surrounding water conservancy projects are closely related to the Dongtiao River.

Although the Dongtiao River did not flow through the ancient city of Liangzhu during the Liangzhu period, it was diverted twice from the ancient Tiaoxi River.

Left: The river network and watershed in the vicinity of Liangzhu Ancient City; Right: The distribution map of water conservancy projects around Liangzhu Ancient City.

Photo courtesy of Liu Jianguo

  According to the statistics of the watershed area, the total area of ​​the Dongtiaoxi River Basin in the upper reaches of Liangzhu Ancient City is about 1483 square kilometers, of which the area controlled by the water conservancy project outside Liangzhu Ancient City is only 52 square kilometers.

  According to the large-scale topographic data, the river network and watershed in the local area near the Liangzhu Ancient City were extracted, and the study found that the Liangzhu Ancient City is located in the southeast of the Dongtiaoxi River Basin. On the watershed, the terrain here is slightly higher, and there will be no water flow, so it should be the best city building site carefully selected by the ancestors of Liangzhu.

  The selection of the best location effectively avoids the threat of floods in the 1,430-square-kilometer water basin in the upper reaches of the Dongtiao River during the rainy season. The Liangzhu ancestors went all out to build a Chinese prehistoric civilization that lasted for thousands of years water conservancy projects.

  He pointed out that the paleoenvironmental research carried out around the Liangzhu ancient city site in recent years showed that during the period 7500-5200 years ago, the surrounding area of ​​the ancient city was a tidal flat facies sedimentary environment rich in foraminifera; and after 5200 years ago, The gradual disappearance of foraminifera means that land began to form.

  The research team worked closely with the Zhejiang Provincial Institute of Cultural Relics and Archaeology, and conducted remote sensing image analysis, field surveys, and test excavations of Liyu Mountain, Gangong Ridge, and Qiuwu on the periphery of Liangzhu Ancient City. From a macro-scale analysis, it is believed that Its water conservancy system may have functions such as flood control, transportation, defense, and irrigation, which are directly related to the economic and social development of the Liangzhu site group and the emergence of the Liangzhu ancient city.

  Four groups of dams constitute the main body of the water conservancy project around the ancient city

  Liu Jianguo said that the water conservancy project outside the ancient city of Liangzhu consists of a series of long dikes and dams, mainly including the Tangshan dam group, the Lion Mountain-Liyu Mountain-Guanshan-Wutong Nong dam group, the Ganggongling-Tiger Ridge-Zhoujiafan dam group, Qiuwu - Shiwu - Bee Nong Dam Group and other four parts.

Left: Conora satellite image of Tangshanba Group; right: distribution map of Liangzhu Site Group.

Photo courtesy of Liu Jianguo

  These four groups of dams constitute the main body of the water conservancy project around the ancient city of Liangzhu. Among them, the carbon-14 dating of Ganggongling, Liyushan, Shizishan, Laohuling, Zhoujiafan, and Qiuwu shows that the construction age belongs to Liangzhu. In the early and middle period of culture, the Tangshan Dam Group is presumed to belong to the same era, which is earlier than the construction of Liangzhu ancient city.

  He said that the construction of the four groups of dams around the ancient city of Liangzhu is huge, and the amount of precipitation they carry has reached the level of once in a hundred years. In terms of flood control, it should be mainly to prevent the threat of heavy rainstorms such as typhoons that land on Liangzhu settlements.

The surrounding water system of the Liangzhu Settlement Group is basically connected to the surrounding water conservancy projects, and resources such as minerals, stones, bamboo and wood in the mountains can be transported to the surroundings of the ancient city by waterway through overturning the dam.

  Among them, the Tangshan dam group connects the Lion Mountain-Wutong Nong dam group, and its exterior is blocked by ditches and water bodies from potential threats from the southern slope of Dazhe Mountain in the west and north. The Dongtiao River is used as a barrier in the south, and the swampy area in the east can form a perfect The defense system protects the settlements of the Liangzhu period, making it the best place for the ancients of Liangzhu to thrive.

  Peripheral water conservancy projects are connected with surrounding and inner city water networks

  Liu Jianguo said that through the observation of the specific geomorphological characteristics of the ancient city of Liangzhu, it can be found that the geomorphic foundation of the ancient city of Liangzhu is actually the bedrock remnants deep into the plain.

The south and north sides of the ancient city are branches of the Tianmu Mountains, the west side is a group of hills dominated by Pingyao Kiln Mountain, and only the east side is a plain that decreases from west to east.

  Taking full advantage of the natural mountains and undulating terrain, the ancestors of Liangzhu chose the site of the ancient city in the area where the relatively high-lying low hills are concentrated in the plain area. As for the severe flooding caused by the main stream of Tiao Creek.

The mountain torrents from Dazhe Mountain in the north and water for production and living were the problems that the ancients needed to solve.

  For this reason, the ancients of Liangzhu built the Tangshan Dam in the front of the mountain according to the characteristics of Dazhe Mountain, and combined with the surrounding mountain topography to form water spaces with different structures.

On the one hand, this can protect the ruins of the Liangzhu ruins group in the low-lying area from the direct threat of mountain torrents; need.

Left: Lion Rock - Wutong Nong Dam Group Conora satellite image; Right: Ganggongling Dam Group and Qiuwu Dam Group Conora satellite image.

Photo courtesy of Liu Jianguo

  He concluded that the water conservancy project outside the ancient city of Liangzhu is connected with the water network around the ancient city and within the city, and plays the functions of flood control, transportation, water transfer, irrigation, etc., which fully demonstrates the exquisite water control wisdom and super water conservancy projects of Liangzhu ancestors Design, organize and implement capabilities.

The site selection of this water conservancy project is very reasonable, and the characteristics of the natural environment were cleverly used during construction to transform a series of mountains, fill up some valley exits, and use the principle of minimal intervention to maximize the water control function and ensure the Liangzhu Site Group. Our ancestors were able to keep harvests during droughts and floods, and had a surplus of food, which promoted the process of social complexity and created a brilliant prehistoric Liangzhu civilization that lasted for thousands of years.

  "Archaeological work has uncovered the mysterious veil of water conservancy projects around the ancient city of Liangzhu, but it should only be the 'tip of the iceberg'. There are still many important relics and phenomena that need to be further discovered and studied in the future." Liu Jianguo said.