Exploration on urban water system planning—taking Hangzhou as an example

Xu Chenghua

(Hangzhou Urban Planning and Design Institute)

1. The background and significance of urban water system planning

Since ancient times, Human civilization coexists with water. Because rivers, lakes, streams, and seas provide easy access to water and navigation, waterfront areas often develop from the original resting places of human beings into dense areas of modern urban business culture. Water is the lifeblood of the city, and rivers contain the history of the city.

The urban water system has many functions such as providing water sources, preventing floods and drainage, receiving sewage, ecological conservation, transportation, leisure and recreation, etc. The water system is the basic natural resource and strategic economic resource for urban development. The water system is the basis for the existence and development of the city. The water system is the key resource and environmental carrier in the process of urban formation and development. The water system is related to the survival of the city and restricts the city's development. develop.

In recent years, due to society’s re-understanding and positioning of urban water systems, some cities have successively carried out the preparation and research of urban water system planning. Since the urban water system plans prepared in various places are based on the diversity of preparation departments and service objects, the planning purposes are different, and the preparation methods are also different. Generally speaking, they are still in the exploratory stage.

As a resource that is close to and closely related to people’s lives, urban water systems play an important role in improving the quality of urban life and highlighting the city’s image. It is of great significance in ecological environment construction and expanding urban development space. As society and government departments gradually realize the prominent position of water systems in the process of urban development and realize that water systems are of great significance to urban planning and construction, the preparation of urban water system planning has been put on the agenda.

The preparation of urban water system planning is a requirement to make good use of water resources, build a good water environment, and promote the construction of waterfront public open spaces. It is also a requirement to improve the urban environment, enhance urban competitiveness, and adapt to the new stage of social economy. The requirements are to build a harmonious society and implement the scientific outlook on development. Therefore, urban water system planning should be one of the important plans in the field of urban planning. Preparing urban water system planning will be a new and important task faced by planners.

2. Contents of urban water system planning

Urban water system planning should focus on ecological construction, guide environmental improvement, enhance the city's image, serve the social economy, and build harmony between humans and water. Urban water system planning should move from a single engineering plan to a comprehensive plan that governs water system protection and construction, reflecting the many functional elements of the urban water system.

Based on the reinterpretation of urban water system planning, urban water system planning focuses on covering the following aspects:

(1) Reasonable water layout

Cities are built on water. The relationship between water and city is very close, and the shape of water system space affects the overall spatial structure of the city. Therefore, the water network should become an important part of the overall urban pattern. On the premise of maintaining urban water network connectivity and forming a continuous water network, rationally plan the urban river network layout structure, determine primary and secondary river channels and water surfaces, and build an urban water network system that is coordinated with the urban spatial structure.

The plan should reintegrate the existing river channels, adjust the unreasonable river direction, and propose new river channels that need to be communicated and added. Coordinate the river course with the planned road, and pay attention to the layout of the river course to make full use of precious land resources.

(2) Ensure water security

Water security is the prerequisite for urban water systems. Water security includes the safety of drinking water sources and the safety of flood control and drainage.

Urban water source security is the primary task of urban water system planning. In the water system planning, the overall layout of urban water sources should be proposed based on the urban water supply engineering plan, and the backup water sources should be clearly defined to ensure the water resources for urban water supply and ensure the safety of drinking water sources. Minimize other water body function settings in urban water sources to avoid unnecessary interference with water quality.

Flood control and drainage to ensure urban safety are the main functions of urban rivers. The water system planning should be based on the layout proposed by the urban flood control and drainage plan, reflect the flood control and drainage planning engineering measures related to the water system, and coordinate conflicts with other engineering facilities.

(3) Improving the water environment

A good water environment is the basis for achieving harmonious and sustainable development of human and water. Good water quality is an important condition for the functioning of the water system. Today, water pollution has become a major problem in the development of many places. The decline in water quality affects the normal and sustainable use of water systems, and the restoration of water quality in polluted rivers is a long process.

Water environment planning in urban water system planning should follow the principle of combining "source control" and "ecological restoration", starting from external source control (sewage interception and management, non-point source control), endogenous source control (bottom source control) Put forward river network water quality management countermeasures in terms of mud restoration), river water supply (water distribution, recycled water, rainwater utilization), etc. In addition to traditional drainage planning, biological treatment technology should also be comprehensively used to control pollution sources, supplemented by river water distribution, re-oxygenation and other measures to restore the river's self-purification ability. On the premise of implementing sewage interception on both sides of the river and water distribution in the river network, water body restoration technology (artificial floating islands, river organisms, mobile aeration facilities, etc.) is used to improve the water quality of the river network. The river bank should pay attention to ecology, avoid mortar construction, improve water permeability, form a natural circulation of groundwater and river water, provide a good habitat for the reproduction of aquatic animals, and increase the self-purification ability of the water body.

(4) Construction of water landscape

Water landscape is the most distinctive part of urban natural landscape.

Water landscape planning should form a landscape system with unique urban characteristics that "takes water as its veins, green as its clothing, culture as its essence, people-oriented, and cityscape blending". It should be combined with the urban water system to show a variety of water landscapes; combined with urban functional areas to create a rich and diverse water landscape; combined with urban green spaces to establish a green network system; combined with urban culture to create a rich personality and place. Unique landscape system.

Determine the classification of river landscape through river landscape evaluation. The rivers are subdivided into important landscape rivers, secondary landscape rivers, general landscape rivers, etc., and landscape planning priorities and design guidance are proposed for each type of river. Design elements such as water body shape, river bank treatment, riverside vegetation, riverside building interface, sight corridors, night lights, landscape nodes and other design elements are used to guide the construction of urban river landscape.

When determining the planar alignment of urban rivers, the natural curvature of the rivers should be maintained as much as possible, and the river sections should be retracted and opened in an orderly manner to return the urban rivers to their natural state. In the landscape planning, make full use of green belts of no less than 15 meters controlled on both sides of the river as a link and passage connecting various park green spaces, square open spaces, and migration of biological species in the city, and become a nearby place for citizens to exercise, have fun, and relax. place.

(5) Reflect water culture

Culture is the soul of the city. The city's culture has a long history and is rich and diverse. The water system is an important carrier of urban culture, carrying the city's profound cultural deposits and thousands of years of cultural heritage. By sorting out, excavating, protecting and developing the connotation and charm of the various river civilizations and historical and cultural resources along the river, the intangible cultural connotation is transformed into tangible material forms, combined with modern civilization, and highlighting the historical and cultural characteristics. Highlight folk culture, highlight the diversity of water culture, and create new water culture with the times.

Many cultures in the city were born and prospered because of water. Such as drinking water culture, water use culture, water control culture, water playing culture, water seeking culture, water eliminating culture, water exploring culture, as well as water-related business culture, shipping culture, bridge culture, dam culture, riverside construction culture, etc. Each river has its own unique derived culture. Through a comprehensive grasp of various characteristic cultures, the overall spatial structure of the river's cultural context should be proposed, and a variety of cultural carriers should be used to reflect it in the water system.

(6) Develop water economy

Water economy is to transform the landscape, environment, engineering and other values ??of urban water systems into economic value. For example, a river with a beautiful environment will bring about an increase in the value of land and real estate on both sides of the river, and water tourism activities will be carried out. Water tourism is one of the important contents of developing water economy.

The water system brings aura and vitality to the city. Water is one of the most indispensable tourism elements. Water tourism can add richness to urban tourism. Water tourism is a close combination of water systems and scenic spots. The good environment of the river and the unique scenery along the coast together constitute a colorful and rich tourism content. Carrying out water tourism can not only reflect the characteristics of the city and shape the image of the city, but also meet the requirements of social development.

Water tourism planning needs to be considered as a whole with urban tourism planning and other tourism resources, closely combined, and coordinated development to build an overall water tourism network that connects internally and externally. According to the distribution of water tourism resources, rivers with certain tourism value are selected, individual scenic spots are connected into chains, and smooth tourism routes are formed by combining waterways and land transportation. Through reasonable organization of tour routes and the development of various forms of tourism activities, an urban river water tourism system that is macroscopically coordinated, microscopically heterogeneous, and suitable for different needs will be formed.

(7) Ordered water space

Human beings are born with hydrophilicity. The life scene of living by water and enjoying water is a realm that people yearn for. With the gradual strengthening of urban economic foundation, the development of waterfront areas has become a hot spot in my country's urban construction, and even the phenomenon of water-friendly economy has emerged.

Waterfront space is the transition area from water system space to land space for urban construction. Its role is mainly reflected in: first, as a place for waterfront public activities to reflect its publicity and enjoyment; second, through the interaction of water environment, green landscape, and architectural landscape, it shows and enhances the urban waterfront. The image of water space; third, it serves as a waterfront biological channel and a non-point source pollution interception site to reflect its ecological nature.

As an important public and open space in the city, waterfront space should be used as a window to highlight the charm of the city. It should emphasize the harmonious life of man and nature, the harmony and well-being of man and man, and should reflect the city's charm. Fairness allows more people to enjoy the city’s most beautiful environment.

Water system planning provides planning guidance and framework urban design guidance for the development of waterfront areas. According to the characteristics and functions of the river channel, the minimum width and regular width of the green lines on both sides of the river are controlled. While ensuring pedestrian continuity, a rich riverside space is formed by combining the development of surrounding land. On the premise of ensuring the blue line of the river and the green line of the waterfront determined by the urban planning, landscape space requirements such as sight corridors and waterfront interfaces are proposed.

3. Hangzhou City Water System Planning

Based on the above analysis, Hangzhou City Water System Planning focuses on the overall layout of the water system, water safety, water environment, water landscape, water culture, water economy, Waterfront space control and other content.

(1) Reasonable water layout

Hangzhou has rivers, rivers, lakes, wetlands, and is adjacent to the East China Sea. It is a Jiangnan city "guided by five waters" Water town.

The urban area is crisscrossed with rivers and dotted with lakes and ponds, forming a unique water system texture. The river and lake systems have nourished the people and made Hangzhou a beautiful place.

Based on the spatial distribution of water resources and water systems, the overall spatial structure of the urban water system in Hangzhou is constructed from three levels: point, line, and surface: rivers are the axis, lakes and streams are the core, and there are five slices and three levels. The Internet becomes a network.

That is, the Qiantang River and the Beijing-Hangzhou Canal form the main axis of the urban water system spatial development, with the West Lake, Xiang Lake and Xixi Wetland as the important core, and the urban water system is divided into five large areas according to the water level characteristics of the river network water system. , namely the Canal water system piece, the Shangtang River water system piece, the Xiasha piece, the Shangsi piece and the Jiangnan piece. According to the weight of rivers in safety, environment, culture, landscape, economy, waterfront space, etc., urban rivers are divided into three levels: main rivers, secondary rivers and branch rivers. Pay attention to the overall water system interconnection method of "points and lines intersecting and connecting into a network" (Figure 1).

Figure 1 Spatial structure diagram of the urban water system

(2) Ensuring water security

Hangzhou’s drinking water sources come from the Qiantang River and Dongtiao Creek in the Taihu Basin. The water system plan clarifies the location of the urban water intake, puts forward requirements for water source protection, and demarcates the first-level protection zone and the second-level protection zone along the upstream and downstream sides of the water intake. The planning of other water systems should avoid adverse impacts on water intakes.

Hangzhou City’s flood control mainly focuses on the river floods of the Qiantang River. The drainage directions of urban waterlogging are mainly the eastern plains of Hangjiahu and Qiantang River. According to the drainage conditions of the Qiantang River and the internal topography and topography of the urban area, the flood control and drainage areas within the urban area are divided into the canal water system area, the Shangtang River water system area, the Shangsi area, the Xiasha area, and the Jiangnan area. The main drainage river channels and drainage pumping stations have been determined.

(3) Improving the water environment

Hangzhou’s water system is a plain river network with extremely low flow speeds and weak self-purification capabilities. By introducing passenger water into urban rivers, the flow rate is increased to dilute the polluted river water, and the self-purification capacity of the rivers is also improved. The water diversion and distribution project uses the Qiantang River as the water distribution source for urban rivers, forming a river network water circulation system of "Qiantang River (upstream) - Canal - Shangtang River - Qiantang River (downstream)". The Shangsi Pian and Xiasha Pian rivers are also introduced into Qiantang The water is distributed from the river source, and at the same time, the urban river water is discharged into the Qiantang River as soon as possible through the Qiantang River Babao Pumping Station, Qibao Pumping Station and other facilities, reducing the possibility of sewage entering the river network in the eastern Hangjiahu plain.

In accordance with the requirements for sewage pipeline construction in urban drainage engineering planning, the construction of sewage pipelines on both sides of the river will be strengthened to intercept sewage discharged into the river, and key sewage interception areas of the Middle River and East River in the old city will be constructed. It is clear that the effluent from the Chengxi Sewage Treatment Plant will be deeply treated and recycled into the canal water system as a supply water source. Use the natural water surface to build Sandun Wetland Park, Chengxi Wetland Park, Xitang River Wetland Park, etc. to treat surrounding sewage. Establish key initial rainwater management areas for Zhonghe River and Donghe River in the old city. Construct key ecological river restoration areas in Qinglong District, key ecological river restoration areas in Chengbei Park, and key ecological river restoration areas in Dingqiao. Build Xixi Wetland Ecological Demonstration Base.

(4) Construction of water landscape

The layout structure of water landscape is: "two belts, three sides and eleven corridors".

Two zones: the canal landscape zone and the Qiantang River landscape zone.

Three sides: West Lake landscape, Xixi Wetland landscape, and Xianghu landscape.

Eleventh Corridor: Determine the primary and secondary river landscape corridors that have an important impact on the urban landscape. Including Yuhangtang River, Shangtang River, Wulitang River, Yanshan River, Xitang River, Zhonghe River, Tiesha River, Hemu Port, Beitang River, Wubaozhi River, Guan River, etc.

According to the different types of urban rivers, they are divided into natural scenery sections, artificial environment sections, historical features sections, commercial and office sections, cultural and educational sections, industrial sections, etc., for residential areas The river landscape is mainly beautified and greened, emphasizing recreation and leisure functions to create a beautiful and tranquil living environment. Emphasize the openness and enjoyment of the river in the center of the public construction, create an urban open space with water features, and combine it with development spaces such as city squares to carry out various water-friendly urban activities, such as the Canal Cultural Plaza , Chengbei Sports Park, etc. The main purpose is to protect and restore the original functions of rivers in historical districts and ancient towns, emphasizing culture and openness, such as Changhe Historic District, Xixing Historic District, Sandun Ancient Town, etc.

(5) Reflect water culture

According to the cultural content and carrier of Hangzhou's rivers, it is determined that "one axis promotes five areas, two belts connect four districts, three Feng Shui areas, and six points" The overall spatial structure of Hangzhou's water system context with "distinguished characteristics".

One axis: the modern cultural development axis of Qiantang River, guiding the trend of modern civilization.

Five films: Five modern civilization films, namely Zhijiang Resort, Qianjiang New Town, Qianjiang Century City, East Railway Station and Xiasha Sub-city, determined based on the recent key construction areas.

Two belts: the Beijing-Hangzhou Canal and the Xiaoshao Canal are two historical and cultural belts, carrying thousands of years of cultural heritage.

Fourth District: Four historical and cultural districts where cultural resources gather, namely the main city old town, Xiaoshan old town, Banshan Historical and Cultural District, and Sandun Historical and Cultural District.

Three Feng Shui Lands: Refers to the three Feng Shui treasures of West Lake Scenic Area, Xixi Wetland, and Xiang Lake Tourist Area. The rich natural resources are the source of the prosperity of Hangzhou’s elegant culture.

Six points: The six water cultural nodes refer to the four following Changhe Old Street, Xixing Old Street, the Gongchenqiao West Historical and Cultural Block on the canal, and Xiaohe Zhi Street at the junction of the canal and the creek. A cultural node featuring the urban style of Hangzhou in the late Qing Dynasty and the early Republic of China, a cultural node in a historical location at the junction of Yanshan River and Wuchang River that reflects the urban style of Hangzhou in the past dynasties, and a modern Jianqiao Bridge on the Beitang River that is characterized by the urban style of Hangzhou during the Republic of China. cultural node.

(6) Develop water economy

“Waterside, Heaven site” is the slogan of Hangzhou’s tourism city brand concept, among which “Waterside” emphasizes Recognizing the important status of water, the “Heaven site” embodies the high-quality experience. Based on the overall positioning of Hangzhou tourism, the decisive role of "water" in creating a waterfront paradise is highlighted, and a water tourism image full of appeal and competitiveness is established.

The plan is to fully tap water tourism resources, extend outward from the relatively narrow water tourism highlights such as West Lake, Xixi, Canal, and Qiantang River, and drive full utilization of the entire water system's tourism resources from point to surface to form a smooth The unique water tourism network makes Hangzhou not only have "water" resources, but also has "water" tourism products, making "water" the first perception of Hangzhou city for tourists.

Revolving around the five major water tourism spots including West Lake, Xixi Wetland, Canal, Qiantang River, and Xiang Lake, we will build a water tourism development center with West Lake as the water tourism development center, the Beijing-Hangzhou Canal and Qiantang River as the dual axes, and the West Lake Scenic Area and Xixi National Wetland Park and Xianghu Leisure and Business Tourism Zone are three water tourism space development structures. Shaping the concepts of ecological water city, cultural water city, prosperous water city, and living water city, four tourist themes are proposed that can be divided and combined: natural experience tour, historical and cultural tour, urban fashion tour, water town style tour, etc.

The Yuhangtang River tourist route, the Canal tourist route, and the Shangtang River tourist route proposed in the plan were launched on National Day in 2008 as three golden water tourist routes in Hangzhou. Along the way, you can experience the beauty and detail of Xixi Wetland, the water transport culture of Yuhangtang River, the pastoral scenery of Shangtang River, the ancient civilization of Beijing-Hangzhou Canal, and the majesty of Qiantang River.

(7) Orderly water space

Water system planning proposes guidance for waterfront space planning. Including general principles, general provisions, development control, development guidance, etc. The general provisions include functional elements, ecological elements, landscape space requirements, protection and utilization of historical culture, transportation access, etc.

A waterfront green belt of a certain width is controlled outside the water control line. The scope of the waterfront green belt is defined by delineating the waterfront green control line. The waterfront greening control line should be arranged as a public green space. The greening should have sufficient publicity and continuity, and waterfront recreational roads should be arranged in conjunction with the waterfront greening control line.

The planning and layout of waterfront areas should maintain a certain degree of spatial openness. Traffic, greening and sight corridors leading to the shoreline should be controlled according to local conditions. The width of the corridor should be greater than 20 meters. Public access to the waterfront should be set up every 200 to 250 meters in the waterfront area. A certain distance should be maintained between roads set parallel to the river and the river to ensure the environmental needs of the waterfront space.

Control a certain area outside the waterfront green belt as a waterfront building control area. There should be sufficient distance between the waterfront building control line and the waterfront greening control line. The planning and layout of the waterfront building control area should fully consider the natural characteristics of the water body, skyline contours, water sight lines, and the impact of building layout on the waterfront landscape, and should be conducive to the shaping of the waterfront space landscape.

IV. Conclusion and Thoughts

Urban water system planning should adopt “reasonable water layout, ensuring water safety, improving water environment, building water landscape, reflecting water culture, developing water economy, and having The positioning of planning goals such as "sequential water space" and the overall goal of "clear water, smooth flow, green shores, beautiful scenery, livable and prosperous" of the urban water system.

Urban water system planning involves many fields such as hydrology, ecology, environment, society, economy, and municipal engineering. It is the result of the simultaneous coupling of natural systems, social systems, and economic systems. Urban water system planning should move from a single engineering plan to a comprehensive plan that governs water system protection and construction, organically connect the plans completed by various disciplines from different angles, coordinate the infrastructure involved in the water system, avoid conflicts and contradictions, and make the planning of various disciplines They complement each other and complement each other, thereby reflecting the integrity, safety, history, coordination and comprehensiveness of the plan.

The preparation of urban water system planning should be divided into two stages. The first stage is urban water system planning, which is equivalent to the overall planning stage; the second stage is the planning of individual rivers, which is equivalent to the detailed planning stage. Under the framework of urban water system planning, a plan for a single river course will be prepared to implement the relevant concepts and plans in urban water system planning.

The technical system and standard system of urban water system planning should be established through the practice of urban water system planning in various places, and preparation methods and technical guidelines suitable for urban water system planning should be formulated to provide scientific basis for the preparation of urban water system planning. , to fill the gap in the country's urban water system planning theory.

Participating in this project are Tang Hairu, Gao Qun, Mao Bin, Feng Yijun, Jiang Jiangfeng, Guiming, Yang Yidong, Ding Xiaoping, Huang Wenliu, Chen Weiwei, Long Yan, etc.