1. Introduction
The evolution of the regional ecological environment is closely related to human civilization. China, India, Egypt, and Babylon (now Iraq) originated from the Yellow River, Ganges River, Nile River, and the Euphrates and Tigris Rivers, respectively. Furthermore, human civilization declined with the exhaustion of rivers; for example, the decline of ancient Egyptian civilization was closely related to the decline of the Nile River, and the cutting off of the Kongque River caused the extinction of the Loulan ancient country in China.
If natural rivers are the cradle of human civilization, canals (or artificial waterways) are the masterpieces of human civilization. Irrigation in Egypt started between 3218 BC and 3035 BC. Early Egyptians relied on river water for natural irrigation. However, due to the arid climate in most of Egypt and the growing population, natural irrigation from river water alone was hard to continue. Ancient Egyptians explored the use of the Nile River for artificial irrigation step by step, including partial basin irrigation and irrigation network systems, to manage irrigation water [
1,
2]. The Egyptian canal culture began during the reign of King Scorpion (approximately 2725–2671 BC) [
3].
The southern region of Mesopotamia, which is southern Iraq now, had a close relationship with the history of water systems (2475–2315 BC), which included artificial waterways, irrigation projects, swamps, and dams (Wilkinson; 2013) [
4,
5], as shown in
Figure 1. During Sargon’s reign (2350–2150 BC), the Sumerians and Akkadians built a complex network of canals. In order to protect themselves from the periodic floods of the Tigris and Euphrates, the Sumerians continued to dredge the silt caused by the two rivers every year to maintain the canal [
6].
Like many other places in the world, Indian civilization flourished around rivers and deltas. The river is still an eternal symbol of national culture. Shaw et al. (2007) believed that the development of advanced irrigation systems in ancient India led to complex city societies and centers. The Indus Valley Civilization Complex (3000–1500 BC) was very prominent in water conservancy projects [
7], as shown in
Figure 2.
In the Western Hemisphere, a kind of indigenous civilization, the Norte Chico civilization, flourished from 3000 BC to 1800 BC. This civilization was mainly composed of four valleys, namely, the Supe, Pativilka, Fortaleza, and Huaura Rivers, in the coastal areas of central and northern Peru; all these valleys share a common coastal plain known as Multipotamia. As early as 3000 BC, there were already very advanced urban centers in Multipotamia. Therefore, Sumeria may have been the only place with a similar degree of urban complexity to that of the city of Multipotamia [
8].
From the above cases, we can conclude that cities are the center of human’s social, economic, and cultural activities and revolutions, and maintaining the healthy and sustainable development and prosperity of cities is an important guarantee for the social and economic sustainable development of a country or region. Water resources play an important role in the rise and fall of cities and regions in the world: developed transportation and perfect water conservancy can promote the development and prosperity of a city and a region; in contrast, the loss of transportation hub status and the destruction of water conservancy facilities often lead to the decline of cities and regions.
China is a large country, and there have been many river systems in the middle and eastern parts of China since time immemorial. The Grand Canal of China was dug as early as 486 BC. Before the Sui Dynasty, a few canals were already dug among water systems; however, they were not connected to each other by that time. When the Sui dynasty unified the whole country, the Emperor Yang of Sui ordered digging of the Tongji and Yongji canals and the connection of the Jiangnan canal with the Hangou canal. The grand canals in the south and the north were connected until then, and the interconnected canal was almost 2700 km long. It was the first time in which the national waterway transportation network was constructed for military and canal transportation purposes in China’s history [
9]. The water transportation network ushered in a fundamental change till the Yuan Dynasty was founded. After the Yuan Dynasty, the Jizhou and Huitong canals were dug to connect the Yellow River and the Weiyun Canal to avoid the high terrain in Shandong. Simultaneously, the Tonghui canal was dug after several twists and turns to achieve water and land transshipment. The Grand Canal from Beijing to Hangzhou was successfully dug, it was at least 1790 km long, and its pattern has been maintained [
10]. Therefore, we can say that the Grand Canal is a human-made canal with the longest existence and longest mileage in the world. It is connected through a series of rivers and lakes in China, allowing commercial towns and agricultural irrigation along the line to develop. It flows mostly through developed regions with dense populations, active agricultural economy, industry, and commerce in China. The Grand Canal also pushes the incredible fusion of economy and culture in different regions of China. It facilitates commercial trade and cultural transmission between China and neighboring countries and regions.
Given the background mentioned above and the importance of the topic, this research aimed to provide an enhanced study on the relations between the rise and fall of China’s canals and cities during the 6th–12th centuries. It aims to provide policy implications for boosting urban and regional sustainable development.
4. Conclusions
A city may form and develop under the influence of various factors, such as ecological environment factors, transportation factors, technical factors, and political factors. As a city, Kaifeng has a history of more than 2000 years, and seven dynasties founded their capital there. The Grand Canal played a decisive role in helping to turn Kaifeng into a flourishing city from an unknown city. As a folk song popular to the folks in Kaifeng goes: “Kaifeng is flourishing if the Bianhe River is unblocked for navigation, but is declined if the Bianhe River is abolished.” It reflects the close relationship between the rise of Kaifeng and the canals. If there was no Grand Canal, there would have been no 168-year prosperity of Dongjing, the capital of the Northern Song Dynasty, or the great painting of the Riverside Scene at the Qingming Festival. By investigating the relations between the Grand Canal and the rise and fall of Kaifeng, we can know that the history of the rise and fall of Kaifeng, to some extent, is the history of the rise and fall of the Grand Canal. In the Warring States Period, the unblocked Honggou water systems caused the city of Daliang (Kaifeng today) to flourish. In the Sui Dynasty, Kaifeng was known as the Bian; it was only a very common county. The Emperor Yang of the Sui Dynasty dug the Grand Canal by taking advantage of the ancient Bianqu Canal, which passed through the county of Bianzhou and laid the status of “nationwide canal transportation center.” In the Tang Dynasty, the political status in the north relied on the cereals transported from the canal systems after the economic focus was shifted to the south. Bianzhou took the opportunity and then developed into a famous commercial capital. Due to the problems of the Tang Dynasty military governors, multiple military governors in the north controlled the grains and taxes. They withheld the grains and taxes without paying them to the central government. Therefore, the Tang Dynasty government had to rely on the counties in the region in the south of the Yangtze River, where the Grand Canal became the lifeline of the Tang Dynasty. The political status of Bianzhou was becoming increasingly important. To consolidate the control on Bianzhou, the government of the Tang Dynasty expanded the city of Bianzhou; such special political protection and advantageous water transportation pushed the urban economy of Bianzhou to develop rapidly. In the Later Liang Dynasty (during the period of the Five Dynasties), in order to acquire the material support of the region in the south of the Yangtze River, Zhu Wen utilized the advantageous water transportation of Bianzhou and founded the capital in Kaifeng. In the Later Zhou Dynasty, the water transportation of Bianzhou became unobstructed as a series of dredging operations were conducted, which facilitated merchants to gather there. After the Northern Song Dynasty founded the capital in Dongjing (Kaifeng today), it was a milestone shift of ancient China’s capital from west to east. In terms of military defense, the geographical position of Kaifeng was not so appropriate; however, Kaifeng was chosen as the capital of the Northern Song Dynasty due to its advantageous economic conditions. The convenient canal transportation in Dongjing (Kaifeng today) in the Northern Song Dynasty allowed industrial engineering and commerce to flourish and prosper and allowed the resident population to increase. Therefore, Dongjing (Kaifeng today) became a more thriving political, economic, and cultural center than other dynasties. After the Song Dynasty ended, three dynasties, namely, the Yuan, Ming, and Qing Dynasties, founded the capital in Beijing in succession; as such, the national political center was shifted out of the Yellow River basin. Moreover, due to the frequent water floods of the Yellow River, the concentrated man-made canals surrounding Kaifeng declined from their prime. Significantly, the construction of the Beijing–Hangzhou Grand Canal in the Yuan Dynasty made the canal transportation avoid passing through the Central Plains. The pivotal role of Kaifeng in the transportation of grains from south to north finally ended in 1411. Since then, the urban status of Kaifeng dropped dramatically, it was marginalized, and its past brilliance is no more.
In China, the canals and the canal-centered cities all rose and fell together. The canal created the necessary conditions for the rise of the city. The shift of the canal inevitably caused changes in the urban size and the rise or fall of the urban economy. In the urban development history of China, such examples are not unusual. Besides Kaifeng, the navigation of the canal between the Yangtze and Huaihe Rivers in the Han Dynasty stimulated the rise of Yangzhou. The canal’s connection in the region in the south of the Yangtze River, the Qiantang River, and the Zhedong Canal pushed Hangzhou to develop into a big economic city from a coastal town. As the canal in the south of the Yangtze River was re-opened for navigation in the period of Yongle (the reign name of the third Emperor Chengzu of the Ming Dynasty), Hangzhou was replaced by Suzhou. As the capital of the Yuan, Ming, and Qing dynasties, Beijing has always been known as the “buoyant city.” Millions of dans of grains and other materials were transported to Beijing via the Grand Canal every year. Jining and Linqing, in the territory of Shandong, developed rapidly after the Beijing–Hangzhou Grand Canal was constructed. In 1855, the waterway from Anshan to Linqing dried up due to the levee burst of the Yellow River. In 1874, the canal ships were replaced by seagoing vessels. In 1900, canal transportation was totally abolished; the traditional canal systems were disassembled. All canal-centered cities, such as Yangzhou, Jining, and Linqing, started to fall, but other canal-centered cities, such as Suzhou, Hangzhou, Wuxi, and Zhenjiang, created new development since the canal in the region in the south of the Yangtze River was still used.
While the canal promotes urban development, it can even profoundly influence the overall transformation of an era. Presently, there are plentiful achievements in the research on Kaifeng of the Northern Song Dynasty in the academic circles of Japan. Naito Konan pioneered proposing the “Theory on Changes in the Tang and Song Dynasties” by relying on the idea that the development of the Grand Canal allowed the commerce of the Song Dynasty to prosper, and a series of changes different from previous dynasties happened in the Northern Song Dynasty [
50]. For instance, the development of canals resulted in the “transportation revolution,” and thereby caused the “commercial revolution,” and finally caused the development of the commerce of Dongjing (Kaifeng today) in the Northern Song Dynasty. It further caused the profound reform in urban development, the disassembly of the traditional neighborhood market, and the emergence of new streets and markets. Since then, the urban development of ancient China entered a new stage.
Moreover, the commercial development resulted in the agricultural, monetary, and credit revolutions [
51]. The prosperous economy laid the material basis for the development of scientific technology. From this, it can be seen that the canal had a very profound influence on the society of the Song Dynasty. As was described by Mr. Qian Mu: “If discussing the changes of China’s ancient and modern society, the most important one is the Song Dynasty.” China before the Song Dynasty was Ancient China, China after the Song Dynasty has been contemporary China. In the Song Dynasty, the politics, economy, society, and life of China were changed greatly [
52].
To sum up, along with the changes in the ecological environment and climate, China’s economic center gradually shifted to the southeast, followed by the shift of the national political center from the west to the east. In this context, the operation of the Grand Canal ran through the entire economic regions of Henan, Hebei, and Jianghuai, thus significantly strengthening the economic exchanges in these regions. When the economic relationship between the regions is increasingly close, it gradually forms a broader economic region, which produces higher-level cities, thus forming a hierarchy system among cities. Located on the canal, Kaifeng was the key to waterway transportation and had an important strategic position. The capital of the Northern Song Dynasty was established there, and Kaifeng developed into the largest city in China and even in the world. After the Northern Song Dynasty, the canal was blocked, the traffic was abandoned, flooding was frequent, and Kaifeng appeared to decline. Since the Qing Dynasty, Kaifeng has lost its position as a transportation hub, and it also declined into a general town in the Central Plains. Through the above investigation and analysis, we can draw the following conclusions.
First of all, land and water transportation is the key factor of urban and regional development. A city is an open system. The smooth connection between the city and the outside is the basis for the survival and development of a city. A city is always carrying out an exchange circulation of materials and population, as well as the transformation and dissemination of information, with other cities and the surrounding hinterlands, where traffic plays a key role. Most of the cities in the world developed into primarily metropolitan areas because they are located on the traffic arteries; likewise, the shift of traffic arteries often leads to the decline of cities. In the Northern Song Dynasty, Kaifeng was located in the regional center of a canal economy, which allowed it to develop into a world-class metropolis with its geographical advantages of water transportation. However, in the Qing Dynasty, although Kaifeng was maintained as the capital of Henan Province, it inevitably declined due to the loss of transportation advantages. Kaifeng is a typical city of this kind in terms of the factors under discussion.
Especially in ancient China, the launching and blocking of the canal played such a key role in the development of a city and region, which was determined by the land and water traffic conditions at that time. The waterway was the most important mode of transportation in the past because of its advantages of low price, large transportation volume, and high speed. Before the rise of modern railway and ocean shipping, inland shipping through canals was the main form of transportation. In order to show the advantages of ancient water transportation, this paper makes a comparison with the prices of passenger and freight transportation in the Jiangnan region of China at the end of the 19th century (
Table 1 and
Table 2). It is not difficult to see that water transportation had a large carrying capacity and longer journey distance, as well as the characteristics of the least labor cost and the lowest price.
From the data in the above two tables, we can calculate that for land transport, the average passenger transport was 400 wen/person/100 li, and the average freight transport was 290 wen/dan/100 li; for waterway transportation, passenger transport was only 150 wen/person/100 li and freight transport was only 7 wen/dan/100 li. In comparison, the passenger transport cost via water was only 38% of that by road, and the freight transport cost via water was even less than 3% of that by land, which shows the advantages of water transport in ancient times. Because of these advantages, the development of water transport often became the key factor for the prosperity of cities in this region.
Second, water resources play an important role in the process of urban and regional sustainable development. Water is the source of life, and any place where human beings live can not survive without sufficient water; the development of a city is no exception. The threat of flood often brings great harm to the development of cities. The floods not only destroy the city itself but also cause economic recessions in the hinterland of the city, and then worsen the environmental support for the existence and development of the city, which seriously restricts the further development of the city. Such problems appeared very prominent in Kaifeng during the Qing Dynasty. The frequent flooding of the Yellow River destroyed many Kaifeng city buildings and traffic arteries and caused the continuous deterioration of the environment in Eastern Henan, with vegetation destruction, ecological imbalance, land desertification, and agricultural production decline, thus accelerating the decline of Kaifeng.
By studying the relations between the rise and fall of Kaifeng and the Grand Canal, we can obtain the following conclusion: Developing transportation; guaranteeing the clear transport of urban goods, personnel, and information; and promoting the development and improvement of urban open economic system and structure are vital to the promotion of a city’s development. Simultaneously, consolidating the construction and improvement of water conservancy facilities, protecting the environment, eliminating flooding, and establishing harmonious development between humans and nature is essential to maintaining the sustainable development of a city.
Nowadays, human beings have entered the 21st century. The development of industry, agriculture, life, and the ecological environment is more dependent on water usage. The water crisis is a major challenge for sustainable development. The progress of science and technology and the development of modern three-dimensional transportation means that inland waterway transportation no longer determines the economic territory and political pattern of a country or region. However, water is still the source of life, and given that the city is the area where residents gather, there must be sufficient water resources and well-functioning water conservancy facilities to form a livable ecological environment by meeting the living needs of the people, the sustainable development of urban industry, and the surrounding agriculture. Therefore, the development of water resources and water conservancy and transportation is still a key factor in the rise and fall of cities and regions. In addition, in recent years, under the influence of global climate change, water resources in many countries have decreased significantly. The tension between supply and demand has become increasingly acute. Some countries have begun to take measures to solve the water crisis. Singapore has tried to solve the water shortage crisis through various ways by managing water resources as the environmental asset of the city and creatively putting forward the ABC plan (active, beautiful, clean waters program) in 2006. “Active” in the name of the project refers to the creation of a vibrant hydrophilic entertainment and community space. “Beautiful” refers to the transformation of concrete canals to integrate with the urban green environment to provide a beautiful waterscape. “Clean” refers to the overall management of water resources and the use of public education to cultivate a more harmonious relationship between people and water to keep water sources clean and improve water quality [
54].
Urbanization is a major comprehensive issue that the world is facing, which involves coordinating with the development of the national economy and is related to the sustainable development of reasonable utilization and the long-term protection of resources and the environment [
55]. At the same time, rapid urbanization has brought great pressure on resource supply and environmental protection; large-scale urban construction has caused the shortage of water resources in cities among 15 provinces in northern China. Many towns in southern China often have serious water supply issues due to water quality problems [
56].
To solve the shortage of water resources in Beijing, Tianjin, Hebei, and other places, as well as provide for the demand for the high-quality development of the Yellow River Basin for water resources, in 2002, the Chinese government began to implement a large-scale “South to North Water Diversion” project, which transports water resources from the south to the north through artificial rivers (
Figure 8). Interestingly, it can be seen from the picture below that most of the Eastern route of China’s South to North water diversion project uses the channel of the original Grand Canal, which also reflects the value and significance of the wisdom of water control and management in ancient China in today’s urban and regional sustainable development.
In order to protect water resources, in December 2016, the Chinese government issued the “Opinions on Comprehensively Implementing the River Head System” and issued a notice requiring all regions and departments to seriously implement it by tailoring their policies to each actual local situation. By the end of June 2018, 31 provinces (Autonomous Regions and Municipalities directly under the central government) in China had fully established the River Head System. These provinces have more than 300,000 river heads at the provincial, municipal, county, and township levels (held by the main leaders of the party and government at all levels in China). Twenty-nine provinces have set up more than 760,000 village river heads, fulfilling the “last mile” of the River Head System [
57]. In addition, the law of the people’s Republic of China on the protection of the Yangtze River came into force on 1 March 2021, which establishes the principle of the sustainable utilization of water resources in river basins [
58].
In addition, with global warming and the scientific development concept of energy saving and emission reduction, green environmental protection is increasingly popular and water transportation has been paid more and more attention again. Vigorously developing inland water transportation is a response to the need to realize the sustainable development of transportation and the need to build a resource-saving and environmentally friendly society. At present, many local governments in China have put forward plans to restore inland water transportation and canal navigation. In October 2019, the 11.4 km section of the North Canal from the Beiguan Sluice to the Gantang Sluice in Tongzhou will realize tourism navigation (
Figure 9). In May 2020, Tianjin Grand Canal’s cultural protection, inheritance, and utilization plan put forward the goal of segmentation of time, sections, and regions for tourism navigation. The 40 km Beijing Tongzhou section of the Grand Canal will be open to navigation before 1 July 2021, and the Xianghe section of the Grand Canal will be synchronized with the Beijing section for tourism and navigation. Although the restoration of navigation of the Grand Canal reflects the value of cultural tourism, the navigation of the Grand Canal can dredge the whole water system, which is of great significance to the comprehensive utilization of water resources, the construction of ecological civilization, and the sustainable development of cities and regions.
Therefore, this study on the rise and fall of the Grand Canal and Kaifeng can further clarify the evolution of Kaifeng and reveal the characteristics and laws of urban development. On the other hand, it can also help us learn from the experience and lessons of ancient water resources development, utilization, and protection, and provide some reference and inspiration for today’s urban and regional sustainable development.