In June 2021, Longyan City, Fujian Province, with its unique natural background conditions and solid foundation work, was shortlisted for the "First Batch of National Sponge City Construction Demonstration Cities" through the selection at the provincial and ministerial levels. In the past two years, Longyan City has closely focused on the goal of national sponge city construction demonstration city, adhered to the new development concept, focused on waterlogging and other livelihood issues, adhered to the construction principle of "infiltration, detention, storage, purification, use, and drainage", coordinated the promotion of urban people's livelihood infrastructure to make up for shortcomings, improve environmental quality, make good use of the best subsidy funds, and systematically promote the construction of sponge city demonstration cities in a point-to-area manner, drawing a beautiful and livable new picture.
At present, the urban waterlogging prevention and control standard has reached "once in 10 years" in the old urban area and "once in 30 years" in the new urban area11 black and odorous water bodies have all been eliminated and there has been no black and odorous phenomenonThe water quality of the main river monitoring sections meets the requirementsThe domestic sewage direct discharge outlet and the blank area of sewage collection have all been eliminated, and the BOD (biochemical oxygen demand) concentration of the influent water of the Tieshan and South Wing sewage treatment plants has met the requirements of the three-year action target of Fujian Province.
Ecological priority and adaptation to local conditions.
Explore the mountain valley construction experience.
The main urban area of Longyan City is surrounded by mountains, and Longmen Creek, Hongfang Creek, Dongxiao Creek, Chenpi Creek and Xiaoxi River join the Longjin River, and the unique landscape pattern has good natural background conditions for rainwater storage and dischargeIt has the characteristics of typical mountainous valley type cities, such as large terrain elevation difference, abundant mountain water resources, concentrated rainfall, and fast runoff formation rate. The construction of sponge city in Longyan City focuses on exploring how mountain valleys can improve flood disaster prevention, soil erosion control, and efficient utilization of water resources through effective control of runoff, so as to form experience in planning, construction, and management.
According to the characteristics of the topography and landform of the mountainous valley type city, Longyan City divides the city into four types: the construction area at the top of the mountain, the construction area at the foot of the mountain, the old city of the river valley and the new urban area of the river valley, and selects typical areas to carry out the construction of sponge city demonstration areas, so as to lead the construction of sponge city in the whole region. Among them, the mountaintop construction area focuses on using the mountain sponge and lake storage space to reduce and retain mountain water, build a rainwater storage and drainage system, fully reuse rainwater resources, strengthen source project control, and build a good regional water ecological environment systemThe construction area at the foot of the mountain focuses on the use of rainwater retention in the valley and the drainage channel, and reuses the rainwater resources for the water replenishment of the lake. Carry out sponge transformation of the source project, set up sponge facilities such as concave green space to reduce source pollution and improve the water environment, and this part focuses on building the Dongxiaoxi area;Through the construction of ecological flood interception ditches, the old town of the river valley collects flash floods and clean water in the form of high water and high drainage, so as to avoid entering the sewage interception system. Make full use of the characteristics of large slope to reconstruct the surface drainage system, strip the rainwater and clean water in the confluence canal and connect the green storage space along the street in the urban area, make full use of the storage and detention effect of green space, improve the drainage capacity of the urban area, eliminate waterlogging points and purify the initial rainwater, this part focuses on building the Dongcheng area;The new urban area of Hegu focuses on strengthening the construction and protection of the city's "large sponge", integrating the "sponge +" concept into the urban construction project, making up for the shortcomings of urban infrastructure through the "sponge +" project, and controlling the projects under construction and proposed in a goal-oriented manner.
Demonstration leads to clear standards.
Create a characteristic construction model of Longyan.
Longyan City has carried out sponge city construction around the construction of a mountainous river valley demonstration city.
In order to better promote the construction of the demonstration area, Longyan City has set up a leading group for the construction of sponge city headed by the secretary of the municipal party committee and the mayor, and has successively completed the systematic implementation plan for waterlogging control, the systematic implementation plan for key areas, the revision of the special plan for sponge city and the regulatory detailed planning for sponge city construction, etc., to build a complete top-level design system for sponge city and escort the construction of sponge city in Longyan City. Regulations and programs such as the Regulations on Sponge City in Longyan City and the Work Plan for Promoting Sponge City Construction Demonstration Cities in Longyan City Systematically and Comprehensively have been issued to effectively regulate all aspects of sponge city construction, improve the management level of sponge city construction, determine the tasks and safeguard measures of sponge city construction of various departments and units, and let all departments work together and promote the sponge city construction work.
On this basis, Longyan City focuses on promoting the construction of demonstration area projects, promotes the construction of systematic global sponge cities through the sponge construction of key areas, achieves "building one piece, achieving one piece", realizes the continuous appearance of the sponge city construction effect and creates a number of model projects, and does a good job in promoting the construction of sponge city in the whole region. A number of sponge city demonstration projects such as Longyan Avenue.
In addition, Longyan City also revised the "Technical Standards for Sponge City Construction in Longyan City" and "Guidelines and Review Points for the Construction Drawing Design of Longyan Sponge City" in combination with local conditions It provides important technical support for the construction of sponge city in Longyan City, ensures the quality of project construction, provides guidance for the construction of sponge city with Longyan characteristics, does a good job in the external display and output of the construction achievements and experience of Longyan sponge demonstration city, and completes the research on the use of valley storage measures to improve the city's flood control capacity in the main urban area.
We have formed a support mechanism for the overall promotion of the project through the establishment of a special project class, a clear division of responsibilities, the implementation of wall chart operations, the establishment of a coordination mechanism, the strengthening of technical guidance, and the strengthening of supervision and inspection, so as to form a replicable and promotable experience in the construction of sponge demonstration cities in mountain valleys while solving the problems in the demonstration area. The relevant person in charge of the Longyan Housing and Urban-Rural Development Bureau said, "We have also established a sponge city construction expert database in Longyan City, and invited well-known domestic experts to guide the sponge construction project in Longyan City." Organize regular training, pay attention to the grassroots training of basic technology of design and construction, and organize on-site observation, exchange and learning of model projects to ensure that the construction of sponge city is 'not out of shape'. Longyan City also promotes sponge city to citizens by carrying out sponge city into campuses, classrooms, and communities, forming a good atmosphere for the whole society to widely participate in the construction of sponge cities.
Make up for shortcomings and make overall plans.
Let sponge cities benefit the people.
Longyan City adheres to the people-centered, uses the sponge opportunity to give priority to solving the problems that have a greater impact on the production and life order of the people, and puts forward solutions and specific projects. In accordance with the idea of systematically promoting the construction of sponge city, closely following the urban construction plan and urban development direction, the sponge city concept is integrated into urban planning and construction projects such as urban renewal and development, renovation of old residential areas, improvement of urban functions and quality, construction of happy rivers and lakes, mountains, rivers, forests, fields, lakes, grass and sand, water beauty cities, and sewage treatment quality and efficiency improvement, and gives full play to the role of buildings, roads, green spaces, water systems and other ecosystems in the absorption, storage and slow release of rainwater, effectively controls rainwater runoff, and realizes natural accumulation, natural infiltration, Natural purification. In the past two years, a total of 153 sponge projects have been implemented as a whole, with a total investment of 195.7 billion yuan.
The second phase of Longyan Avenue is 2709 years longIt is 4 meters wide and 78 meters wide, and belongs to the main road of the city. In the construction, 37,940 square meters of sunken side sub-belts and curb green belts, and 27,100 square meters of permeable brick pavements for sidewalks and non-motorized lanes, the total annual runoff control rate reached 71%. Make full use of the terrain characteristics, highlight the control of road runoff pollution at the source, organically combine the end with the ecological environment improvement of the Dongxiao River Basin, pay attention to the combination of landscape and function as a whole, realize economy, applicability and low maintenance, and create an upgraded version of Longyan sponge road.
The Longyan Park Tiantang Flood Storage Wetland Project is positioned as flood water storage, ecological protection and wetland purification. The project covers an area of 20 hectares, and the construction of flood storage wetland covers an area of 52 hectares, with a flood storage capacity of 130,000 cubic meters, adopts the control measures of excess runoff combining drainage and storage of "flood channel-flood storage wetland", and arranges hydrophilic natural education space along the drainage channel and wetland based on the ecological means of "light and shallow wilderness", forming a natural landscape and hydrophilic space of "flood channel-flood storage wetland", so as to realize the multiple functions of controlling excessive runoff, enhancing the flood control and drainage capacity of the area, providing public rest space and carrying out ecological education. In addition, the project integrates the functionality and landscape of water, and the north inlet part is the main entrance of the wetland, and the stepped purification tank in the upper lake area is used as the pre-quality treatment of water quality. Detention ponds, pond gardens and garden ponds have achieved the functions of urban image, and seasonal canals have achieved the functions of urban flood detention and water regulation. The Xiahu area to the south is the main water storage area, which realizes the landscape function and finally flows into the garden pond. The project gives full play to the function of the wetland to conserve water sources and purify water quality, further improves the water quality ecology of the Yuantiantang area, and comprehensively utilizes water resources while eliminating the hidden danger of waterlogging in the basin, helping the construction of sponge-themed ecological wetlands in the north of the city and the construction of the sponge city demonstration area in the north of the city.
Longdi Dongshang Bay is a typical sponge building community in Longyan City, with a land area of 28,310 square meters, through the construction of modular green space, while absorbing the surrounding rainwater while maintaining the original landscape quality, the construction of rain gardens, permeable pavement, grass planting ditches, linear ditches, to achieve a total annual runoff control rate of 74%.
Longjin Lake Park is a typical sponge park, and it is also a business card of sponge city construction in Longyan City. Under the condition of heavy rainfall, the rainfall in the lake storage area in the park can be used to solve the problem of high flood level on both sides of Dongxiao River and Hongfang River, and alleviate the drainage pressure of the downstream municipal pipe network.
The CD plot of Dongshan Wetland Phase I is a typical sponge-type water system with a land area of 13540,000 square meters. In terms of overall construction ideas, the wetland water system should be fully utilized as a large sponge body for storage in the Dongshan area to achieve the purpose of rainwater collection and storageThrough ecological revetments, dry creek terraces and other facilities, the purpose of purifying rainwater is achievedRational use of the collected rainwater for reuse, to achieve the purpose of in-situ collection and in-situ utilization. Dongshan Wetland has the background advantage of the drainage end, which plays the role of storage, filtration and purification of rainwater in the entire Dongshan area, creates an ecological revetment landscape of harmonious coexistence between man and nature, highlights the contiguous effect of node projects and the area, and coordinates the overall improvement of water security, water environment, water resources and water ecology, while also providing recreational space for the surrounding people, satisfying the people's pursuit of a better life, and playing an effective role in the promotion and display of sponge city construction.
The Longyan Cave Ecological Comprehensive Improvement Project is a typical mountain sponge park with a land area of 12562 hectares. The project takes mine restoration as the core, combines the concept of sponge city construction, and uses the elevation difference of high east and low west and the direction of rainwater collection to design the landscape water system. The water system, gentle slope stream and Longqiu Pond in the park are organically connected together, and valley storage, rainwater terrace, natural slope protection, ecological dry stream, mountain pond, vegetation buffer zone, etc. are set up according to the topography, so as to reduce the discharge pressure of mountain floods on downstream municipal pipelines, improve the prevention and control standards of waterlogging in downstream urban areas, play a positive role in rainwater management and flood control and drainage in the mountains around the city, improve the water ecological environment, and is the embodiment of the effectiveness of urban ecological restoration.
Longyan City will continue to deeply understand the connotation of sponge city construction, make every effort to build a sponge demonstration city in mountain valleys with Longyan characteristics, form a set of replicable and popularized sponge city construction experience model, and make Longyan contributions to the construction of sponge cities in China. The relevant person in charge of the Longyan Housing and Urban-Rural Development Bureau said. (Lin Fuqiang, Gao Yingbin, Cui Tingyu).
*: China Construction News.