(General Office of Ministry of Water Resources)
Li Daoyuan's Notes on Water Classics in the Northern Wei Dynasty is a world-recognized geographical classic. Taking water as the key link, the book describes the track of human activities in history, and preserves the corresponding cultural relics as much as possible, which has amazed readers of all ages with its profound observation and pen and ink spirit. Unfortunately, there is no picture to set off the original text, so it is difficult to understand the macro meaning of its brushstroke at a glance. Yang Shoujing, a beginner at the end of Qing Dynasty and the beginning of the Republic of China, drew a set of Notes on Shui Jing, and by using the method of overprinting historical maps of Zhu Mo created by him, he dropped the contents of the book (with black pen) on the measured map (with red pen) that just appeared at that time, which opened the door for people to read the Notes on Shui Jing in depth.
On the map of Shui Jing Zhu, the black characters representing the contents of Shui Jing Zhu fall on rivers and watersides of different sizes. The farther away from the river and water, the thinner the black letters are until a large area is blank. In history, the relationship between human activities and water is smooth; Residential areas and cities are the places where human activities are most concentrated, and a lot of precious information is left in Shuijing Note. The expression of "water proving ground" is the most intuitive scientific description of the relationship between man and water, and the relationship between city and water should start from here.
I. Theories and models of cities and urban construction
(A) Enlightenment from the market
In ancient times, with the development of production, surplus products appeared, followed by private property and its exchange. The place of this exchange is the city, and the expansion of the city has appeared the original city. The appearance of this city is no accident. Cities are densely populated, and production, life and commodity exchange are inseparable from water. It can be said that rivers, lakes, springs and wells as water sources are the choice objects of cities. According to legend, "Boyi makes wells", Boyi is a follower of Yu's water control. China has a long history of using water wells. In the early literature, the word "marketplace" often appeared. "Justice in Historical Records" said, "The ancients had no cities and no wells. If they pump water from the well, they will sell goods by the well, so they say it is a market. " This is the truth that "well is the city" and "business must be the city". The original relationship between human beings and population settlements and water is clearly expounded here.
(B) from the long-term practice of urban construction theory
It took a long time to get from a crowded place to a city. In this process, in the process of getting along with water, people have explored various experiences in building homes and cities, gradually formed regular things, and thus produced theories. The Spring and Autumn Period and the Warring States Period were relatively mature, and the representative expression was Guanzi, which mainly involved:
"All the founding capital, not at the foot, will be above Guang Chuan. High is not close to drought, and water is enough; Don't go near the water, but the ditch is safe. Because of natural materials, it has advantages. Therefore, battlements don't have to be in the rules, and roads don't have to be good. " ("tube ride") is to choose the location of the capital (or city), neither too high nor too low. Because it is difficult to get water, it is necessary to get enough urban water at a lower level; Very low, too close to the water, the flood control task is too heavy, and the flood control and drainage project can only be saved if it is properly higher. Using favorable terrain and water conservancy conditions to build, there is no need to stick to a certain architectural model.
"Therefore, a saint in a country will be in an impartial place, and he will choose a place of fat forgiveness, around the countryside and mountains, and pass water to Jose. Write it in the ditch and note it because of Dachuan. " (Guan Zi Du Du) It means that building a city should not only be on fertile and stable land, but also facilitate the layout of water conservancy projects. The built city should be surrounded by water veins, which is convenient for water intake, smooth drainage and direct injection into rivers. Paying equal attention to water supply and sewage discharge is conducive to improving the environment and flood discharge conditions.
"The benefits of returning to the land are the benefits of the city, the Guo outside the city, and the land outside the Guo. When the ground is high, it is a ditch, and when it is low, it is a dike. Life is called Jincheng. " ("Guan Du Du") It means that on the selected city site, a city wall should be built, a Guo should be built outside the wall, and a ridge should be built outside the Guo. Dig ditches for water diversion and drainage in high terrain, and build dikes to block water in low terrain.
Flood control, water diversion and drainage, "If the city wall is thick, the gully is shallow and deep, and the door is condescending, those who should be repaired but not repaired will go up." (Guan Zi Q) It means that the size of a city's buildings, whether it should be built or not, are very important matters, and both kings and leaders should ask.
The following three pictures are sketches of Beijing, Tianjin and Kaifeng in Ming and Qing Dynasties. As can be seen from the figure, although the times are far apart, the relationship between the above theory and the practice of later generations is so close (Figure 1, Figure 2 and Figure 3).
Figure 1 Beijing City Map in Ming and Qing Dynasties
(C) Urban model tempered by theory
The above theory, after long-term practice, has formed a complete urban construction model, and its skeleton can be shown in Figure 4. Of course, due to terrain or other specific restrictions, it can be modified, but the basic elements must be available. Villages and towns, wharves along the river and commercial ports are not included.
Figure 2 Map of Tianjin in Ming and Qing Dynasties
(D) The benign relationship between people and water needs perfect urban functions.
Cities are developed from population gathering and have a closer relationship with water. In the history of our country, this point has been comprehensively and systematically dealt with, thus satisfying the functions of the city. Its contents can be summarized as follows:
(1) water supply and drainage. Cities must be built in places where water is convenient. The most ideal place is, of course, the banks of rivers and lakes, where groundwater is abundant, which is convenient for drilling wells and diverting water from construction projects. This is the basis of "proving land with water". Due to some special reasons, such as military needs, without this condition, we can only divert water from a long distance, and the amount of work is large, so we can only do it.
Figure 3 Map of Kaifeng City in Song Dynasty
Water supply mainly solves drinking water and daily life water, including agricultural nursery and forest irrigation. What should also be mentioned is fire prevention, which was particularly important in ancient times when wooden houses dominated. The above situation has been recorded in a large number of ancient documents.
While paying attention to water supply, cities must pay attention to drainage, because it is absolutely indispensable to maintain a good living environment in cities.
Fig. 4 Schematic diagram of ancient urban construction mode
(2) Flood control and defense. In ancient times, cities occupied an extremely important position in the offensive and defensive. In order to consolidate the city defense, most cities have built strong city walls, and at the same time dug deep moats around the city, also known as pools or cities, so the city was called the city in ancient times. The water in the moat should come from the rivers and lakes outside the city, with water diversion channels, drainage channels and a series of hydraulic structures as the guarantee of normal operation, which is a complete water conservancy project system. The defense function of urban system is only needed in special period, while the function in normal period is flood control. Because of the need of water supply, cities must be built in rivers or other places where water passes. Once the flood comes, inundates the fields and rushes to the city, you can close the city gate in advance and block the flood out of the city with earth plugs. People outside the city can also take refuge in the city before the flood comes. When the flood is besieged, the moat naturally becomes a channel for guiding water and draining water (Figure 5).
Fig. 5 Road map of river flooding around Beijing in Qing Dynasty
(3) shipping. Cities are inseparable from traffic. In ancient times, land transportation had low road standards, heavy vehicles, limited traction power, high cost and small traffic volume. The advantages of water transportation are large volume and low freight. Many dynasties took the construction of canals to communicate with various natural water systems as the national traffic trunk road. There was a canal outside and a canal inside, which was the best mode of transportation for the city at that time. There are many relics or relics of canals in important ancient cities.
(4) Improve the urban towel environment. Broadly speaking, the above water supply, flood control and water transportation all belong to the urban environment; And the environment here refers to the living environment. Cities are densely populated, and there are many human activities, which have great influence. Vegetation decreases, air is dry, temperature rises, water quality and air pollution, and the natural environment deteriorates. Our ancestors realized in long-term practice that introducing water into cities with water conservancy projects or transforming them with natural water bodies as the environment for building cities, the water bodies in these cities or suburbs became the conditions for improving and even beautifying the living environment. People think so and do so. For example, Chang 'an in the Tang Dynasty was the largest city in the world at that time, with a large population and prosperity. There are 1 1 streets in the north and south, and 14 streets in the east and west. There are ditches on both sides of every street, forming a crisscross water network all over the city, and the ditches are full of tall poplars. The water is clear and the trees are in rows. Gardens, palaces and ponds of all sizes are all over the city. Such an elegant environment is guaranteed by adequate water sources and water supply facilities (Figure 6).
Figure 6 Chang 'an City in Tang Dynasty
Second, look at ancient water and cities from the ancient urban heritage.
(Urban structure that has remained unchanged for more than 2,000 years.
Among the cultural relics preserved so far in the Song Dynasty, the monument in Pingjiang is the most striking. Suzhou was the capital of Pingjiang River in Song Dynasty, and the monument was engraved with a detailed city map at that time. It is extremely valuable information for studying the history of urban development and urban water conservancy in China.
Suzhou City was founded on Saturday (5 14) and was the capital of Wu in the Spring and Autumn Period. At that time, the city had eight doors and eight waters, and it was a water network city with equal emphasis on land and water from the beginning. With the development of economy, Suzhou is becoming more and more important, and it is one of the important economic centers in China. The Sui Dynasty moved the city to the southwest under Hengshan Mountain, but the natural and economic conditions of the new site were far worse than those of the old site. Obviously, this is a comparison of water environment in terms of water diversion, drainage and transportation, so it must be moved back. By the Song Dynasty, the economic center of the whole country had moved to the south of the Yangtze River, and Suzhou's position was even more important. The city is prosperous, and the waterway transportation through the Jiangnan Canal can reach the whole country. The monument clearly reflects the situation of urban water network at that time and its close relationship with moats and canals. Its eight gates and Watergate also correspond to the Spring and Autumn Period. After the founding of the People's Republic of China, a lot of archaeological work was carried out in Suzhou, and it was found that there were 6 ~ 7 layers of rubble and historical sites. Comparing the Pingjiang Monument with the map of Suzhou City around 1949, or going back to the records of Wucheng in the Spring and Autumn Period, we will find that not only the position of the city gate has not changed, but also the mysterious landscape of ancient buildings and the twin towers are exactly the same. The fundamental reason for this "eternal" urban evolution is the role of water network as the skeleton of the city. Suzhou's urban water network layout makes full use of water sources, topography and the connection with the surrounding areas, which is difficult to change. At this point, we have to be impressed by the high wisdom and creativity of our ancestors (Figures 7 and 8).
Fig. 7 Pingjiang map
Figure 8 Suzhou city map
(2) the ancient city model exhibition board
Yecheng, located in Linzhang County, Hebei Province, was founded in the Spring and Autumn Period and was an important town of Wei during the Warring States Period. At that time, Ximen Bao ordered Ye to divert water from Zhang to irrigate the farmland around Ye Town, which became the foundation of Wei's prosperity. During the Three Kingdoms period, Cao Cao made a patio weir here and a 12 dam in Zhangshui, forming a 12 diversion step. An irrigation diversion canal is opened on each dam, which is called the Twelve Channels of Zhangshui, bringing agricultural prosperity and prosperity to Yecheng. Zuo Si described in Du Wei Fu: "Twelve streams have the same origin and different mouths. Livestock are clouds, and drainage is rain. Soak (moisten) japonica rice (rice) and plant (plant) millet. This is a mulberry tree, and it is very oily. Even the fields are zoned, but the houses are scattered. Ginger is full of flowers, peaches and plums are shaded. " This is the living environment of Yecheng at that time. In the ninth year of Jian 'an in the Eastern Han Dynasty (204), Cao Cao attacked Yecheng occupied by Yuan Shang, and once led Zhang Shui to fill the city. Due to the wall's blocking, water did not enter the city. Later, Cao Cao took Yecheng as the base, vigorously managed the city, introduced Zhangshui into the city, and then drained it out of the city. Clear water flows through the streets, Gao Qiao flies, trees are shaded, the sound of water is gurgling, and cars and horses are noisy, which is beneficial to painting and drinking water. There is also a very vivid description of this fu.
In the south of Yecheng, there is a Huan River (now Anyang River), and a tributary named Huan Water Branch has been artificially opened. The river is divided into two branches, the south branch leads to the canal white ditch opened by Cao Cao; It starts from the moat outside the east wall of Yecheng in the north and reaches Zhanghe in the west. These two feeder lines are navigable, so Yecheng's external traffic is very convenient. Cao Cao also opened a Xuanwu pond in the west of Yecheng, which is connected with the above transportation modes and used as a dock for stopping ships and a port station for throughput. Later, a large garden named Xuanwu Garden was built around the pool. The garden has deep trees, beautiful flowers and plants, Jing Ya waves and bright buildings. Shui Mu's reflection gardens and criss-crossing canals constitute the urban characteristics of ancient Yecheng, and its soul is water (Figure 9).
Fig. 9 Yecheng Water System Map
(3) How many West Lakes are there?
There are many West Lakes in China. In addition to the famous West Lake in Hangzhou, there are many southwest West Lakes rich in water, and even some cities in the north have little water. For example, Fuzhou in Fujian, Huizhou in Guangdong, Yingzhou in Anhui (now Fuyang) and Xuchang in Henan have West Lake; Even some counties, such as Xianyou in Fujian and Fushun in Sichuan, have West Lake. Wengshanbo (now the Summer Palace) in Beijing is also known as the West Lake scenery. Their common feature is that they are all in the west of the city. In most parts of China, the terrain is high in the west and low in the east. Water is located above the city, and it can flow into the city by itself. Most of them have the function of water supply, which can solve the domestic water consumption of residents, irrigate garden plants and even farmland, enjoy vegetables and improve the environment. When we visited the town with the West Lake, the situation was not bad (figure 10, figure 1 1).
Figure 10 Schematic Diagram of Huizhou City and West Lake in Guangdong Province
When we talk about the West Lake, we can't help thinking of two famous people: Bai Juyi and Su Dongpo.
"New Tang Book Bai Juyi Biography" contains: "For the secretariat of Hangzhou, build a dike to guard Qiantang Lake, drain its water and irrigate thousands of hectares; After the recovery of Li Mi Liujing, the people depend on it. " When he left office, he left a famous sentence "Other people": "Old people build roads, pots are full of pulp, there are no trees in Gan Tang, poor households have to shed tears and pay more taxes, farmers are hungry for dry land, and only one lake is left to save you from famine." It shows the mind and pursuit of politicians and the important position of water.
Su Dongpo, as the autonomous prefecture of Hangzhou, comprehensively managed the West Lake, making its benefits develop from single item to comprehensive utilization, which became the lifeblood of Hangzhou's survival and development and laid the foundation for the capital of Hangzhou in the Southern Song Dynasty. He was an official in Huizhou and Yingzhou, and also built the West Lake, which has made achievements for local development that will be remembered for generations to come. The story of Su Dongpo and the Three Lakes left an eternal story in the memory of China's city and water.
Figure 1 1 Schematic diagram of water conservancy in jiande city, Zhejiang Province
Bai Juyi and Su Dongpo are not only outstanding writers, but also outstanding officials and experts in water conservancy projects.
(4) Several ancient cities with the same appearance.
In China's urban planning, there are at least three medium-sized cities with outstanding characteristics and extremely similar shapes. They are Liaocheng in Shandong, Huaiyang in Henan and Yongnian in Hebei, all square ancient cities surrounded by a circle of lakes, forming a unique "city in the lake" landscape. Here is an interesting story about the city and water.
In some cities in the north of China, in addition to building city walls and moats, flood levees have been built for a week at quite a distance outside the city, which is actually a tucheng, surrounded by ditches. When the flood comes, it has the same function as the city. In this way, the city has two flood control lines, which not only increases the safety guarantee rate, but also expands the flood control area. The above three cities all fall into this category. Some rivers in the north are full of sediment, such as the Yellow River and Haihe River. When they are flooded, they will carry a lot of sediment. When they reach the plain, the velocity slows down and the sediment drops, especially in cities. When Liaocheng encounters this situation, there will be a lot of sediment deposited outside the embankment. Over time, the sediment deposition outside the dike became thicker, the depressions inside and outside the dike became deeper and deeper, and the accumulated water became a lake. We can call it a city lake. According to the survey, outside the west gate of Huaiyang City, the bottom of the lake is 5 meters lower than the flat land outside the dike! The lake around the city is now called Chenzhou Lake; Similarly, the lake around Liaocheng is called dongchang lake; The lake around Yongnian is called Yongnianwa (Figure 12 ~ Figure 14). Let's look at the situation in Cao Xian County. The water in its berm has dried up, but there is still a lot of water in the city. This is related to the fact that the berm was destroyed, sand-laden flood flooded into the berm, and the wall was still intact, which made the ground outside the wall higher than that inside the city (Figure 15). There are many such examples, and some abandoned urban bases have even become a big lake. Liu Tianhe, a river management official in the Ming Dynasty, once described it as follows: "The land outside the embankment of Binhe County is gradually silting up, and the city is in good order from the bottom of the embankment." This kind of landscape is more common in areas where sandy rivers are flooding.
Figure 12 Map of Huaiyang City, Henan Province
Figure 13 Liaocheng, Shandong Province
Figure 14 Map of Yongnian County, Hebei Province
Figure 15 Cao County, Shandong Province
(5) Urban memory that should not be forgotten
Yichun City, Jiangxi Province is adjacent to Yuanjiang River in the north, hence its name Yuanzhou. As the terrain inclines from south to north, the water level of Yuanjiang River is lower than that of Cheng Jie Street, which brings inconvenience to residents. There are many fires in cities and many losses in history. After a fire in the Tang Dynasty, Yuanzhou was rebuilt. In 809 AD, in order to solve the problem of fire prevention, Li Jiangshun, a state official, organized people to open canals to divert water and improve water use conditions. The water source is selected from the upper reaches of Liqing River, a tributary of the south bank of Yuanjiang River. "I irrigated 20,000 fields and decided to go into the city again, winding around the alley, which was deep and wide enough for ships to pass." This channel comprehensively solves the needs of all parties in urban water use. In memory of the founder Li Jiangshun, it was named Li Qu. Some people write poems in praise; "Ben and the residents struggled to put out the fire. They walked all the way and paid for the detour. The moon is bright at night, and spring is everywhere. When washing your hands, the cold noise is strange in the street, and the broken lights and red shadows see the balcony. When I leaned against the railing, I knew I had a purpose for the pavilion. " With the appearance of tap water in modern times, Li Qu lost its original function, but its head and channel were still used for irrigation. Channels in cities have been transformed into urban drainage tunnels (Figure 16 and Figure 17).
Figure 16 Map of Yichun City, Jiangxi Province (1)
Figure 17 Map of Yichun City, Jiangxi Province (2)
(6) The eternal swan song from prosperity to destruction
Sizhou has disappeared from the map for more than 300 years, and has remained in people's memory for a long time for two reasons: First, it was once one of the most important water transport hubs in China; Second, it ended in sinking into the vast Hongze Lake, and there was no drastic geological change, which was really rare.
Sizhou City is located in the north of Xuyi County, Jiangsu Province. Before sinking, it once faced Xuyi across the Huaihe River. It is very low. It is estimated that the bottom of the city is between 8 and 9 meters above sea level, but now the water level of Huaihe River here exceeds 12 meters. In the dry season, when the water level is lower than 1 1 m, the submerged city walls and bridge remains can still be exposed to the water. Of course, the sinking of the city is related to the formation and development of Hongze Lake later, but it is also a basic fact that its ground elevation is too low. The most important section of the Grand Canal in Sui Dynasty is Tongji Canal, which connects the Yellow River and Huaihe River. It was called Bianhe in Tang and Song Dynasties. Goods from the south to the north pass through the Grand Canal and Huaihe River, and then transfer from Bianhe River to the capital Chang 'an, Luoyang or Kaifeng. Due to the poor navigation conditions of Huaihe River and Bianhe River, ships need to be repaired or transshipped here, and the business of serving boat people has developed rapidly, and it enters Huaihe River at Bianhe River. Due to frequent floods in Huaihe River, the flood control task of Sizhou City formed in low-lying areas is quite heavy. In the Song Dynasty, a strong city was built on the east and west banks of the Bianhe River, and an outer dike was built outside the city to form two lines of defense.
In the Jin Dynasty, the north and south confronted each other, the Bianhe shipping declined, the status of Sizhou City weakened, and immigrants from the Yellow River and South China seized the Huai River into the sea, blocking the discharge of Huai water and gradually forming Hongze Lake. In the late Ming Dynasty, the water level of Hongze Lake kept rising, and the threat of flood to Sizhou City became more and more serious, and the city turned to the stage of only surviving. In the late Ming Dynasty, the general plan of harnessing the Yellow River by bundling water and attacking sand was implemented, and Gaojiayan was built, which made the water level of the lake rise, the city roots were immersed in the water for a long time, and the stone wall foundation site gradually collapsed. The water level outside the city is higher than that inside the city, the market is flooded and the environment is extremely deteriorated. 1680, sizhou city was finally submerged by the raging lake (fig. 18).
Figure 18 Sizhou Water System Map in Three Periods
(7) Unforgettable urban inheritance
Shouyang or Shouchun, now Shouxian County, Anhui Province, was called Shouyang or Shouchun in ancient times. The city can reach the Yangtze River through the Huaihe River and its tributaries, namely Feishui, Shi Shui and Chaohu Lake. Through the Huaihe River and its tributaries, Shui Ying and Shashui can enter the Yellow River basin, or turn to Si Shui, Si Shui or river water along the Huaihe River to enter the Yellow River. Historically, it has experienced a long-term division of north and south with the Huaihe River as the boundary. Shouyang became a battleground for military strategists because of its convenient position as a water transport hub, especially in the Southern and Northern Dynasties. In the south of the city, there was a large-scale water conservancy project-Shaopi built in the Spring and Autumn Period, which irrigated a large area of land south of Huaihe River, became an important agricultural area, and increased the military status of the city.
Shouyang also has a military disadvantage, that is, low terrain. Huaihe River accepts two tributaries, Weihe River and Pi River, above the Feihekou River, which is prone to floods, and fat water often has the opportunity to flood, so the threat of floods to cities is very prominent. Therefore, after years of practice, Shouyang City has formed a strong urban system. During the Northern and Southern Dynasties, the water army attacked frequently in the war, and this system withstood many severe tests. In the second year of Jian Yuan in the Southern Dynasty (480) and the fifth year of Chen Taijian in the Southern Dynasty (573), there were wars in which the city was submerged by civil war, and Shouyang City has been well preserved so far. Especially in the 15th year of the Southern Liang Dynasty (5 16), in order to capture Shouyang City occupied by Wei Jun, a famous dam, the Floating Weir, was built in Fushankou, Wuhe County in April of that year, so as to submerge Shouyang City and drive away Wei Jun. After the completion of the weir, Wang Yang was built within hundreds of miles on both sides of the Huaihe River. As for how deep the water is inside and outside the city, there is no record. Coincidentally, in September of the same year, the Huaihe River flooded, and the Fushan weir was destroyed by the flood peak, and the downstream was greatly affected, but Shouyang City occupied by Wei Jun remained the same.
Shouyang City, now called Shouxian County, the ancient city pool is still preserved, the city wall is still intact, and its maintenance, reinforcement and even management are the responsibility of the Water Conservancy Bureau, which is unique in today's urban management (Figure 19).
(8) Mooring rings for windows on the second floor
When it comes to urban flood control, we can't help but talk about an unnoticed detail in Wuzhou, Guangxi: mooring rings are fixed on the second floor windows of some street-facing buildings. The insider said that when the flood came, the rising water level could submerge the first floor, so the owner gave up the first floor, and the second floor became the main place for family activities, and the ring window became the entrance. In the meantime, you can disembark from the second floor through this door to achieve contact with the outside world until the flood exits. This is also an unforgettable urban heritage.
Figure 19 Map of Shouxian Town, Anhui Province
More and more attention has been paid to modern non-engineering flood control measures, which can lower the standard of fortification projects and save a lot of engineering costs, and are most suitable for cities with skyrocketing floods. It shows that the non-engineering measures of flood control have been successfully applied to flood exit in the history of our country.
Third, cherish the heritage of ancestors.
China's achievements in urban development and construction have gone through thousands of years, which has made inestimable contributions to the prosperity of the Chinese nation. Today, its physical remains are few. Today, we study it and know it not to "paint a tiger according to a cat", but to analyze and identify it, find out what is beneficial to today, and get application and prosperity in modern times. For example, the concept and practice of flood control; Experience in comprehensive utilization of water; Concept and practice of optimizing human settlement environment with water. Facts have proved that many things we regret afterwards are brought about by ignorance of inheritance and sublation.
In many places, we have conscientiously inherited and carried forward the legacy of our ancestors. For example, the restoration of the ancient capital; Shaoxing urban river network construction; Some cities have achieved good results in river regulation and greening.
But some practices should be thought-provoking. For example, should moats in some cities be abandoned? Why do some river network cities fill some canals? Why some new cities or urban areas are often flooded; The water pollution in many cities shows our ignorance and rashness about the remains of our ancestors.
The Chinese nation is a wise nation, not an empty talk. I think our knowledge and understanding of our ancestors is far from enough. There is still a lot of work to be done in the study of cities and water.