Clear waves protect the central axis. How did the water system of the central axis evolve?

Beijing is a city with a dense network of rivers and lakes in history. It was born and prospered because of water. "Water" carries the transportation of the capital, nourishes the royal gardens, maintains the lives of the people, and enriches the poetry of literati... "Water" provides water sources and guarantees supplies for the development of Beijing. At the same time, it also shapes the soul of Beijing in its "silent existence", bringing life and vitality to Beijing.

In the long course of historical changes, the once crisscrossing network of waterways in Beijing has accumulated into a kind of urban imprint. These "water traces" carry the water charm of Beijing and witness the vicissitudes of the city.

Backed by mountains and embraced by water is a common construction image followed by ancient Chinese cities, and Beijing is no exception. The water environment pattern of Beijing's central axis is divided into six sea systems extending from Xihai to Zhongnanhai and moats surrounding multiple city walls. The ancient capital's water veins interwoven by the six seas and moats gave birth to the unique graceful rhythm of the central axis under the solemnity.

Old photos of Neijinshui River

1. The land of fish and rice before the birth of the central axis

A complete map of Beihai Park in the 14th year of the Republic of China

The Daning Palace of the Jin Dynasty was located on Qionghua Island in the northeastern suburbs of Zhongdu City. It was first called Taining Palace and later changed to Wanning Palace. Regarding the construction process of this palace, Emperor Qianlong of the Qing Dynasty once said in the inscription of "Baitashan General Record" erected on Baitashan in Beihai today:

"Baita Mountain is the Qionghua Island of the Jin Dynasty. The Beiping Atlas records that it was called Yaoyu during the Liao Dynasty, which may be the place."

Emperor Qianlong, who prided himself on his erudition, speculated that Qionghua Island had already existed during the Liao Dynasty's Nanjing City, and was then called Yaoyu. Due to the long history, there are different opinions on who first used the palace on Qionghua Island. In the Qing Dynasty, some people believed that Empress Xiao of Liao dressed here, while others believed that it was the place where the concubine of Emperor Zhangzong of Jin dressed. Gu Taiqing, a poet of the Qing Dynasty, once said in "Searching for the Site of the Dressing Table of the Empress of Liao" that "it is difficult to verify the events of the time based on the remains, and we should ask the residents for information", which shows that the initial development process of Beihai was complicated and confusing, and there are still many unsolved mysteries.

The construction of the Daning Palace in the Jin Dynasty began in the 19th year of the reign of Emperor Shizong of Jin (1179), which is generally considered to be the historical starting point of today's Beihai Park. Tao Zongyi of the Yuan Dynasty once recorded the story of piling up earth to build mountains and palaces in the Jin Dynasty in his book "Chu Geng Lu". The book records that the rise of Mongolia in the late Jin Dynasty posed a serious threat to the border. After observing the qi, the Feng Shui experts told the rulers of the Jin Dynasty that there was a sacred mountain on the Mongolian Plateau, and there was a royal aura on the mountain. The mountain must be dug to stop the royal aura from rising. Therefore, the emperor of the Jin Dynasty sent envoys to Mongolia and proposed to dig the mountain. Mongolia was already strong, so it was naturally impossible to agree to the request of the Jin Dynasty. The helpless rulers of the Jin Dynasty mobilized soldiers to dig a lake in the northeast suburbs of Zhongdu City, pile up earth to build a mountain, and then there was Qionghua Island and Daning Palace. The Jin Dynasty's mountain digging and aura could not stop the Mongolian cavalry from moving southward. Soon, Zhongdu City was occupied by Mongolia. In the fourth year of the Zhiyuan reign of Emperor Shizu of the Yuan Dynasty (1267), Kublai Khan ordered people to build a palace city with the lake of Daning Palace as the center, and the Yuan capital city was gradually completed.

The stories recorded by Tao Zongyi are both fictional and factual. Qionghua Island stands in the lake, and it is clear that the lake existed earlier than Qionghua Island. In fact, the lake was first excavated in the Jin Dynasty, and a small island was built near the east bank of the lake, which is Qionghua Island. According to the research of scholars such as Hou Renzhi, a famous historical geographer, the Liuhai water system including today's Beihai was originally the old course of the ancient Yongding River. After the ancient Yongding River was diverted, the original riverbed accumulated water to form a lake, and the Gaoliang River flowing through today's Zizhuyuan Park was poured into it. Before the construction of the imperial palace in the Jin Dynasty, nearby residents had already used the lake for fishing and planting. Before the birth of today's central axis, this place was once a pristine land of fish and rice.

2. Six Seas Extending from the North Sea

The construction of the Yuan Dynasty capital city was centered on Tuancheng in Beihai, which became the intersection of the palace complex. In the Yuan Dynasty, Tuancheng was a small island located in the Taiye Lake, on which the Yitian Hall was built. Wooden bridges were built on both sides of Tuancheng. Crossing the wooden bridge on the east side, you can directly reach the core of the capital city - the palace city. To the north of the wooden bridge on the west side is the Xingsheng Palace where the empress dowager lived, and to the south is the Longfu Palace where the crown prince lived. Tuancheng, located between the three palaces, is the connecting point of the main building complex of the Yuan Dynasty capital city, and its importance is self-evident.

Map of Yuan Dynasty Capital

In the Yuan Dynasty, a moat was built around Tuancheng. The moat was only 1 meter wide, the protective wall was about 1 shichi (0.33 meters) high, and the water depth was about 0.5 meters. There was a saying in old Beijing that "one-foot-high low wall is impossible to jump over, and three-foot-high guardrail is not dared to jump over". The "one-foot-high low wall" is the protective wall of Beihai Tuancheng, and the "three-foot-high guardrail" is the guardrail of the moat of the Forbidden City. In the expansion project of Jin'ao Yudi Bridge in the 1950s, the moat of Tuancheng was filled and turned into a sidewalk.

The lake around Tuancheng was called Taiye Lake in the Yuan Dynasty, and "Taiye Autumn Wind" in the Eight Scenic Spots of Yanjing refers to this. Taiye Lake is located in the imperial city and is the source of water for the palace. In order to ensure the water quality of Taiye Lake, the Yuan Dynasty separated Taiye Lake from Jishuitan where the Grand Canal Wharf was located, and diverted spring water from Yuquan Mountain in the western suburbs and injected it into the lake from the north and south sides of Taiye Lake. This is the Jinshui River. The southern tributary is also called "Longfu Palace Front River" because it passes through the south side of Longfu Palace. As a result, the spring water of Xishan is exclusively enjoyed by the royal palace. When Jinshui River passed through Gaoliang River, Xihe River and other rivers in the Jin Dynasty, it took measures to divert water by troughs to avoid the confusion of clear and turbid water, which was called "cross-river hopping". At first, "washing hands was prohibited in Jinshui River", but the ban was gradually relaxed. During the reign of Emperor Yingzong of Yuan Dynasty, some people even washed horses in Jinshui River, and Emperor Yingzong of Yuan Dynasty had to reiterate the ban.

The terminus of the Grand Canal in the Yuan Dynasty was Jishuitan, also known as Haizi. In order to allow more ships to berth at Jishuitan, the famous water conservancy expert Guo Shoujing introduced the water from Changping Baifu Spring into the lake, deepened and reinforced Haizi, and built Haizi General Wharf. Ships and merchant ships along the canal gathered and berthed, and there was a grand scene of "the oars that raised the waves were more numerous than the fish in the East Sea; the masts that galloped in the wind were more numerous than the bamboo shoots in the South Mountain". In the 30th year of the Zhiyuan reign of Emperor Shizu of the Yuan Dynasty (1293), Kublai Khan returned to Dadu from Shangdu. When he passed Jishuitan, he was very happy to see that the lake was "covered with boats and ships" and named the canal Tonghui River. Unlike the Taiye Lake within the deep palace walls, there were many restaurants and shops on both sides of Jishuitan, making it an important commercial and trade center in Dadu.

Among the 14 heritage sites on the central axis of Beijing, the only bridge is the Wanning Bridge between the Bell and Drum Tower and Jingshan. The Wanning Bridge in the Yuan Dynasty was also known as the Haizi Bridge. It was an important hub where the Jishuitan River merged into the Tonghui River. On the west side of the Wanning Bridge, there is another important sluice gate, which was originally named the Haizi Gate and later renamed the Chengqing Gate. Some scholars believe that the Yuan Dynasty capital city extended north and south with the Wanning Bridge as the tangent point. The radius of the capital city was determined based on the maximum inclusion of the original natural water surface into the capital city, so as to build the city wall of the capital city. However, there are continuous low-lying areas in the east of the capital city, which is not suitable for building city walls, so the eastern city wall of the capital city is slightly retracted.

The Ming Dynasty was the period when the West Six Seas took shape, and the function of water transport was gradually replaced by the scenery of the water town. After the Ming army occupied Yuan Dadu in the first year of Hongwu (1368), in order to facilitate defense, the northern wall of Yuan Dadu was moved five miles south, and another northern city was built on the river channel that connected to the Bahe River east of Jishuitan. In this way, the northwest part of the waters of Jishuitan was isolated outside the city and evolved into the later Taiping Lake. Because of the large number of reeds, it was also called "Reed Pond". After the founding of New China, Taiping Lake was filled and became a subway vehicle repair shop.

Because the Ming Tombs were located in Changping, the Ming court abandoned the Baifuquan Wengshan River on the grounds of protecting the Fengshui of the imperial tombs. The Jinshui River that flowed into the Taiye Lake gradually became obsolete, and the water source of the Taiye Lake had to be introduced from the Jishuitan. The Taiye Lake and Jishuitan, which were separated in the Yuan Dynasty, were connected again. Because the water from the upstream must first ensure the water supply of the imperial city, the water from the Xishan Spring first flowed into the Houhai through Desheng Bridge, Li Guang Bridge, and three bridges after flowing into the Jishuitan, and then flowed back into the Qianhai. This is the landscape of "watching the mountains and waters flow backwards from the silver ingot". At the same time, the southern part of the Taiye Lake was further excavated into a lake in the Ming Dynasty, and today's Nanhai was initially formed. Later, Yingtai was built, and the royal forest garden pattern consisting of the North, Middle and South Seas was formed. The Tonghui River, which connects Jishuitan and Tongzhou, was enclosed in the imperial city in the Ming Dynasty. After the Datong Bridge outside the Dongbianmen was built in the third year of Zhengtong (1438), the grain ships no longer entered Beijing, and the Jishuitan wharf gradually disappeared.

The Six Seas Pattern in the Ming Dynasty's "Collection of Lanes and Alleys in the Five Cities of the Capital"

After the Ming Dynasty's reclamation and transformation, the originally connected "Haizi" was divided into three lakes. The lake west of Deshengmen was still called "Jishuitan", the lake in the middle was called "Shichahai", and the easternmost lake was called "Lotus Pond" because it was full of lotus flowers. In the Qing Dynasty, due to the intensification of artificial "sea reclamation" and the decline of the flow of Xishan spring water, the water area of ​​the West Six Seas gradually decreased, and finally formed the West Sea, Back Sea, Front Sea, North Sea, Middle Sea, and South Sea.

3. Clear waves protect the central axis

Beijing, with its unique four-layer wall structure, has taken the construction of the moat water system of traditional Chinese cities to its extreme. As early as the Tang Dynasty, before the appearance of today's central axis, many river remains of Jicheng during the Sui and Tang dynasties were discovered near Yongdingmen. The moat water system of Beijing's central axis was constructed in the Yuan Dynasty. Today, the clear stream outside the Yuan Dynasty Capital Ruins Park is the remains of the moat. The southern moat of Yuan Dadu City is on the east-west line of the Great Hall of the People today. When the Great Hall of the People was built in 1958, the ancient river channel of the Yuan Dadu moat was discovered. The walls of Yuan Dadu were built with rammed earth, and the moat was also protected by rammed earth.

The excavation of the moat in the Ming and Qing Dynasties began with the construction of Beijing during the Yongle period of the Ming Dynasty. In the early Ming Dynasty, Beijing was five miles south of the northern city wall of Yuan Dadu, while the southern city wall was two miles south. The city wall was built with stone slabs, and the banks of the moat were also changed to stone banks. The inner city moats on the central axis of Beijing include the North Moat and the Front Three Gates Moat. The North Moat was excavated on the basis of Gaoliang River and Taiping River. The Front Three Gates Moat is located on the south side of Zhengyang Gate, Xuanwu Gate, and Chongwen Gate. It is a river that runs through the center of the city and is also the main outlet for drainage of rivers and lakes in the inner city. After the outer city was built in the middle of the Ming Dynasty, the Front Three Gates Moat became the North Moat of the Outer City. The water source of the outer moat mainly comes from the diversion of the West Gate, and another part comes from the Xiangshan Diversion Canal opened in the 38th year of Qianlong (1773), which flows into the moat through Yuyuantan and Sanli River.

General map of the capital drawn by the Japanese during the Qing Dynasty

In the south of the Forbidden City in the Ming and Qing Dynasties, there is the Inner Jinshui River, the largest water supply and drainage canal in the palace city. The name of the Jinshui River in the Ming and Qing Dynasties was taken from the Yuan Dynasty, but the flow of the Jinshui River in the Yuan Dynasty is completely different. The Inner Jinshui River flows into the palace wall from the culvert of the northwest corner tower, then flows south along the west side of the inner wall, passes the Wuying Hall and the south side of the Taihe Gate, crosses the Inner Jinshui Bridge, passes the Wenhua Hall to the east, and flows out in the southeast corner of the Forbidden City as the Outer Jinshui River. In order to ensure drainage, many underground drainage ditches were built in the Forbidden City. These drainage ditches and branch ditches finally flow into the Inner Jinshui River. The source of the Outer Jinshui River comes from Zhongnanhai, flows through the Weaver Girl Bridge, passes through the Sheji Altar and the front of the Imperial Ancestral Temple, and is famous for passing through the Outer Jinshui Bridge. The Inner and Outer Jinshui Rivers silently guard the core building complex on the central axis, witnessing the nirvana process of the Chinese nation from suffering to revival in modern times.

Changpu River is the lower reaches of Waijinshui River. In the Ming Dynasty, it was the inner river of "Dongyuan". It was named because there were many cattails on both sides of the river. Cattail is calamus, which is a kind of medicinal material that can eliminate evil spirits. During the Dragon Boat Festival, old Beijingers often used calamus and mugwort to insert on both sides of the door to ward off evil spirits. Unlike the magnificent Forbidden City, the East Garden on the bank of Changpu River is elegantly decorated and simple. It was the place where the emperors of the Ming Dynasty fasted. The Niulang Bridge on the Changpu River was later demolished. In the early days of the founding of New China, the river was covered with a cover and became an underground river. It was not until 2002 that the renovated Changpu River Park was reopened, and the restoration of the water system of the central axis took another solid step.

Author: Li Cheng