Analysis on the expansion of green space

Analysis on the expansion of green space

In recent years, people have realized more and more strongly that protecting the earth's ecological environment, expanding the area of green space and planting trees are to protect human beings themselves. But the reality is there, the population is increasing, the need of living and living leads to the decrease of cultivated land area, but the earth can't become big, so people begin to develop into space, engage in balcony greening and roof greening. As a form of greening that does not occupy the ground land, the application of space greening is more and more extensive. Its value lies not only in adding green to the city, but also in reducing the radiant heat of building materials roofs and weakening the urban heat island effect. If it can be well used and popularized to form an urban aerial greening system, it will greatly improve the urban environment.

First, understand the significance and characteristics of balcony and roof greening

Balcony and roof greening can be broadly understood as a general term for gardening and planting flowers and trees on roofs, terraces, roofs, balconies or artificial mountains of various ancient and modern buildings, structures, city walls, bridges (overpasses). At present, it is of great significance to promote balcony and roof greening: first, increase the area of urban green space and improve the deteriorating human living environment. Roof greening can not only purify the air, but also improve the ecological environment. It has an obvious effect on absorbing the radiation of sunlight, restraining the temperature rise, adjusting the indoor environment temperature and alleviating the thermal effect. The second is to improve the present situation that natural land and plants are replaced by high-rise buildings and hard pavements of many roads in the city; The third is to improve the urban heat island effect caused by excessive felling of natural forests, various waste gas pollution, sandstorms and other hazards to human beings; Fourth, it is of great significance to open up humanistic green space, build garden cities, improve people's living conditions and quality of life, beautify the urban environment and improve ecological effects; Fifth, the development of greening in the air can free up limited land resources for plant construction and expand production. At the same time, while doing a good job in balcony and roof greening and landscape design, through scientific and reasonable planning and layout of factories, factories and roads, a visiting corridor is designed to guide guests into the roof garden and enjoy the leisure landscape, which can not only save intensive land, but also reflect the advanced ecological concept of the enterprise.

Balcony and roof greening are also called? The fifth three-dimensional green surface? It is estimated that if a city makes full use of the roof area for greening, the carbon dioxide above the city will be reduced by about 80%.

At present, there are three obvious characteristics of balcony and roof greening in China. First, the temperature and humidity conditions are poor. Due to the high position of the roof, the surrounding area is relatively empty, the wind speed is higher than the ground, and the water evaporates quickly. The higher the roof is from the ground, the worse the greening conditions are. Second, there are some limitations in gardening and plant selection. Due to the limitation of roof bearing capacity, it is impossible to have a soil environment completely consistent with the ground. Therefore, the height difference of landform should be avoided in design, and tall trees with deep roots or fast growth should be avoided in plant selection. Third, the boundary rules of green space. Roof shapes are generally regular geometric shapes, which appear repeatedly, especially in residential areas.

Second, the main ways of balcony and roof greening in China

Due to the diverse design of buildings, roofs of different sizes, heights and shapes, combined with novel and changeable layout design, and the use of various plant materials and ancillary facilities, various types of roof greening have been formed. Roof garden is divided into low-rise building roof garden and high-rise building roof garden according to height. According to spatial organization, it can be divided into three types: open, closed and semi-closed; No matter what kind of roof garden, its design method is roughly the same as that of the ground courtyard. From the use function, it can be divided into several main types, such as garden nursery type, scaffolding type, courtyard type, lawn carpet type, three-dimensional multilayer type, garden type, economic development type and so on.

At present, there are three main ways of roof greening: one is aimed at the light roof with weak bearing capacity and no greening design in advance, the carpet planting with grass seeds suitable for a small amount of planting soil, and the carpet greening with various ground cover plants. If patterning is adopted, the effect will be better. For example, Shanghai Academy of Agricultural Sciences has successfully applied it to light flat roof greening? One-time leveling technology for roof greening? This technology has obtained the national intellectual property patent and passed the certification of Shanghai high-tech transformation project. It has an application area of over 50,000 square meters in Shanghai and Beijing, and is the largest roof greening promotion project in Shanghai and Beijing. This technology selects Sedum sarmentosum of Sedum family, which has short meat quality, creeping growth, branching on nodes, self-propagation, extreme drought resistance, cold resistance, barren resistance, green in winter, green in spring, water and labor saving, and almost no management is needed. Lawn blocks cultivated in the base with 2 ~ 3 cm thick matrix materials can be planted on the roof at one time. Compared with the roof treatment methods such as painting, laying plastic sheets (mats) and changing slopes, the cost is lower. Experts and the media say that this Sedum is the best plant for roof greening at present.

Secondly, for the roof with strong bearing capacity, garden greening with trees and shrubs should be planted. This method is suitable for large roofs, mostly used in high-end hotels, hotels and high-rise buildings, which makes the roof space change greatly and produces rich and colorful effects. For example, a rooftop garden on the east side of Hangzhou Wulin Square was built on the roofs of two three-story buildings and connected by arch bridges. There is a football field and more than 50 kinds of flowers and trees are planted in the garden. All the year round is like spring, which is several times higher around it.

Third, the combination, that is, free placement, mainly in the four corners of the roof and the side of the load-bearing wall with potted plants' roof greening', which is more flexible. Which way to choose depends on the load of the roof, the location of the load-bearing wall, the flow of people, the surrounding environment, the use and so on. Scaffolding greening is used to plant vines, such as grapes and kiwifruit, because the cultivation substrate and scaffolding columns can be placed on the load-bearing wall, and the load of scaffolding and plants is small. This greening method has less load on the roof, which can be borne by ordinary roof structures, and is especially suitable for the roof of low podium in front of high-rise buildings. For example, sweet potatoes, peppers and flowers are planted on the roofs of some buildings in Chongqing; Some roofs in Chengdu have not only planted flowers, but also built nurseries, medicine nurseries and melon gardens. The green roof area exceeds 6,543,800 square meters, and there are hundreds of roof gardens, with a larger garden area of 2,000 square meters.

Third, the current situation of roof greening in China

Roof greening has been developed abroad for many years. However, China has just started. Since the 1960s, China began to study the construction technology of roof garden and roof greening. With the process of reform and opening up in China, tourism has made unprecedented development. In order to improve the urban ecological environment and increase the urban per capita green area, roof gardens, roof greening and roof flowers have really entered the scope of urban construction planning, design and construction. If 30% of the existing flat roof area of 69.79 million square meters in the built-up area of Beijing is used for roof greening, it is equivalent to building 27 Zizhuyuan parks in the central area of Beijing, which can increase the urban green space by 7.698 million square meters, increase the annual dust retention of green space by 65.438+092.45 tons, and increase the annual absorption of sulfur dioxide by 3.95 tons, thus greatly improving the air quality. According to incomplete statistics, the number of roof greening buildings in Beijing is less than 1% of the total number of existing buildings in the city. At present, there are hundreds of green roofs in different periods, covering an area of about 600,000 square meters. The green roof area in the built-up area of Beijing is about 69.79 million square meters, of which 70% are multi-storey roofs (below18m) and 30% are high-rise buildings. Roof greening construction in other provinces (cities) in China began in the 1960s. With the rapid development of domestic economic construction, the evaluation of living environment and quality of life has been paid more and more attention. For example, in Chongqing, Shanghai, Shenzhen, Hangzhou, Changsha and other major cities in China, roof greening is carried out spontaneously in various forms.

In February, 2005, Shanghai gave legal support to roof greening and incorporated it into the Regulations of Shanghai Municipality on Greening Management, becoming the first city in China to regulate roof greening by legislation. In March 2005, Chengdu specifically stipulated that all newly started buildings in Wucheng District, Longquanyi, Qingbaijiang, Xindu, Wenjiang District, Shuangliu County and Pixian County in Chengdu must be stamped as required. All buildings built in Chengdu within the last 20 years, with clear property rights and meeting the safety requirements of housing construction should be afforested on the roof according to the conditions. What is the cost of roof greening? For prizes? Policy, and implemented by the city, district and community organizations? Excellent roof garden? Waiting for the selection activity. Although the roof greening technology is mature at present, it is difficult to popularize and apply it in Chinese cities, and the progress is slow. Take Shanghai as an example. The huge Shanghai has more than 200 million square meters of roofs. At present, the green area is only10.2 million square meters. A drop in the ocean? .

Four, several methods of current roof greening design

1. Garden roof greening can be made into a small garden to serve tourists, mostly for service buildings? Such as hotels and restaurants. , can provide guests with leisure and entertainment space. Small gardens should have appropriate undulating landforms, with small pavilions, flower stands and other garden architectural sketches, and dotted with rocks. Choose small trees with shallow roots to match with shrubs, flowers, lawns, vines, etc. In order to meet the needs of plant root growth, the thickness of planting soil should be 30 cm to 40 cm, and the local design can be 60 cm to 80 cm. This kind of roof garden should pay special attention to the overall consideration in architectural design, in order to meet the requirements of roof garden for roof bearing capacity, and try to make the heavier parts (such as pavilions, flower racks, rocks, etc.). ) is designed on the beam and column. 2. The patterns of color blocks are composed of foliage plants such as Buxus buxus, Berberis purpurea and Ligustrum lucidum, or neat and gorgeous grass flowers and lawns, which have a good overlooking effect and are mostly used for low-rise roof greening when roofs are staggered. Because we pay attention to the overall visual effect, there is no garden road inside, only the management channel is left. 3. The seasonal arrangement adopts potted flowers, which can be changed at any time according to their full flowering period, and chlorophytum can be placed on the edge of the building, taking into account the greening of the wall. This method is mostly used for low-rise roof greening. At the same time, we should also pay attention to coordination, unity and diversity to form a rhythm.

(1) The Government should strengthen the implementation of the roof greening policy.

First of all, the government should formulate relevant industrial policies and regulations and incorporate roof greening into the overall urban planning as soon as possible. Formulate quantitative indicators for three-dimensional greening, especially roof greening, for new buildings or residential quarters; It can also be stipulated that projects without roof greening planning and engineering construction will not be approved and accepted. Support and encourage the greening and renovation of the roofs of old residential areas and buildings, and put green clothes on the roofs of old and new residential areas and communities. Secondly, we should make full use of economic levers such as tax reduction and exemption to support and guide real estate and property management enterprises to develop roof greening. At the same time, formulate relevant laws and regulations as soon as possible. At present, China has not yet issued regulations specifically for roof greening. The urban landscape department can only promote the roof greening work in the form of full government investment or certain subsidies to the units that have completed the roof greening. 2005 is the year of experimental promotion of roof greening in Beijing. The government invested 6.5438+0.3 million square meters, but without the government's promotion, the enthusiasm of enterprises for roof greening will fade. A famous person once said? Do you have it now? Garbage building? It is still spreading, and roof greening legislation is imperative. ? More and more people in the industry are calling for making relevant laws and regulations as soon as possible, vigorously promoting roof greening and making more cities full of vitality.

(two) the development of roof greening technology and construction standards.

By formulating the technical standards of roof greening, a series of problems such as waterproofing and anticorrosion in roof greening have been solved. At present, some cities have formulated norms and standards. In 2005, Beijing issued the Beijing local standard "Roof Greening Code".

(3) Strengthen the management of roof greening construction.

A long-term management mechanism should be established for roof greening. Roof greening construction should be implemented in accordance with the principle of who uses, who builds and who manages. All responsible departments and units must simultaneously build and manage, and provide guarantee in terms of manpower, financial resources and material resources. By establishing a long-term management mechanism, ensure that the maintenance work is truly implemented. All relevant departments should conscientiously do a good job in the ideological work of residents and mobilize residents to support and cooperate with the construction and implementation of roof greening. All departments, units, street offices and neighborhood committees should establish a sense of the overall situation and actively and effectively cooperate with the implementation departments and units to do a good job in roof greening construction. The Planning Bureau is responsible for comprehensively coordinating the roof greening scheme implemented in combination with the new project. The Bureau of Landscape Architecture is responsible for the planning, scheme validation, technical guidance and related coordination of roof greening, as well as the implementation of subsidy fees. Cooperation of roof greening in residential property companies. The housing and land bureau is responsible for the roof greening construction of newly built, rebuilt, expanded, completed and unfinished residential projects and systematic houses. All departments and units are responsible for roof greening construction. The roof management after greening must abide by the following provisions: it must obey the unified management of the housing management unit; Shall not affect the use and management of the original public facilities; Shall not interfere with the normal inspection and management of the relevant administrative departments; It shall not affect the original fire fighting and hedging functions. Roof greening is managed and maintained by the property management unit; Non-public roof garden, non-management personnel are not allowed to enter. The roof afforested by the owner at his own expense shall, in principle, be managed and maintained by the owner or user who implements greening, and may also be entrusted to the management unit for management and maintenance; If the owners or users do not obey the management due to poor maintenance, the housing management unit shall order them to make rectification.

(four) to deal with the ownership of the roof garden.

If the house is owned by a single owner, it shall be borne by the property owner. If the house is shared by multiple owners, it shall be solved in the following ways: First, the top-level owners or users shall be encouraged to afforest at their own expense, and after the unified planning of the housing management unit and the consent of more than 30% of the property owners, the top-level owners or users shall manage and use it themselves. Second, non-residential houses are organized and implemented by the housing management unit, and the property owners bear the proportion of property rights. Third, if the roof is purchased by the owner or distributed by the development unit, it shall be borne by the owner or user. If new laws and regulations are introduced to privatize roof property rights, private funds can be mobilized to green the roof space of the city. At present, it is popular in the property market to buy a roof garden and send it to the roof garden. It is impossible to write the roof garden into the purchase contract or property certificate. Consumers often have only the right to use and no property rights. Consumers' use and transformation of the top floor space is often very limited and may be taken back at any time. If the roof is privatized and the property rights are clear, the top-level owner can apply for the roof real estate license and allow it to be traded as an accessory part of the top-level house, so that the owner can safely carry out the greening transformation of the roof and the investment channels for roof greening will be expanded accordingly. You can sell the roof to the top floor residents, who are responsible for greening. There are no hard and fast rules for planting varieties. As long as it can play the role of greening the roof and purifying the air, whether it is planting trees, flowers, grass or vegetables, the architectural design is allowed.

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