Content
General definition of urban open space proposed for use in the UrbSpace Project
Generally speaking urban open space is a generic term covering all non-built up spaces within the administrative boundaries of a town or city. In this sense urban open space includes all ‘outdoor’ spaces including streets and squares, woodlands and agricultural areas as well as traditional parks and gardens. In its broad sense urban open space also covers both publically as well as privately owned land, but also water areas.
The justification for this is that the precise location of the city boundaries is usually a matter of ‘historical accident’ rather than being a function of the overall urban morphology of a settlement. As a result the boundary may include some land still in semi-rural uses in some cases, while it is drawn entirely within the built up region of others.
More recently the concept has been expanded to include those parts of the built fabric which are open to the sky, including roofs, terraces, balconies etc. and even building facades, where these can be clad with vegetation.
In addition there is a growing category of covered urban spaces which
should also be considered as having an important open space character, in particular large public and semi-public atriums, shopping malls etc. These are in particular important as they can have an important linking function between other categories of open space, and have a public character in terms of the number of people they attract and the way in which they are used.
As a consequence of this extended definition is important as urban open space can be seen as a continuous matrix of space within which all the built components of the city are situated, and which flows between and over the buildings, linking the urban centre with the surrounding peri-urban and rural landscape. As such it can be seen as representing an essential part of the basic infrastructure of all urban areas.
Although it is important to see urban open space as an undivided resource, it is also useful to be able to differentiate between its main component parts. There are various ways in which this can be done, including ownership, management responsibility, accessibility, structure and use.
There is a simple assumption that public ownership is always associated with public accessibility and un-restricted use, but this must not always be the case. Different possible combinations of these factors need to be considered. It is important to remember that it is not only public spaces which can be influenced by public policy. There are a number of ways in which private spaces can also be influenced by planning regulations and public grants for example.
Understanding the varied functions of urban open spaces is an important part of helping to improve their effectiveness, both by enabling better management of existing urban spaces as well as improving the design of new ones.
There are many attempts to list these functions, but the following summary divides the functions up into three main groups:
• Environmental and ecological functions
• Social and societal functions
• Structural and aesthetic functions
Enviromental and ecological functions include:
Climatic a melioration
Open spaces can help to improve the climate of urban areas in a number of ways which are independent of the actions of people:
• Open spaces dominated by vegetation convert the solar radiation they absorb into sugars (photosynthesis) and therefore heat up less than adjacent areas, thereby helping to cool the surrounding air.
• The physical effect of shading by tree canopies and shrubs is also potentially a very significant one.
• The presence of cooler areas caused by green open spaces within towns and cities also helps to generate air movements as heavier cool air flows from cooler to warmer, more densely built up, areas.
• Evapo-transpiration from the vegetation also cools and moistens the surrounding air, something which is even effective in the case of relatively small open spaces.
• Areas of open water will also have a significant effect on reducing temperature levels overall, as well as of the fluctuations between day and night. This is a scaled down version of the oceanic climate effect.
• If open spaces are located in line with the direction of the prevailing winds this can help air circulation within the urban area – this if effective whether or not these spaces are dominated by vegetation, but with vegetation they can have additional benefits.
• Vegetation, especially belts of trees and shrubs, can be effective in removing particulate pollution from the air, as it becomes deposited on the leaves as the air-flow is slowed down by the vegetation barrier.
• A similar effect provides shelter from prevailing winds for people and dwellings located downwind. This can have a significant impact on the perceived climate and on the need for heating in buildings thus sheltered.
Noise screening
The effectiveness of open space in acting as a noise barrier is limited unless additional measures are taken. The impact of vegetation screening is small, but a combination of open space, earth mounding and planting can be an ideal solution.
• Green open space separating noisy land uses from ones requiring quieter conditions, can be effective in reducing noise levels in adjacent areas.
• This is more effective if they are characterised by dense tree and shrub planting, which can absorb noise to a limited extent.
• However, the major part of this effect is the psychological reduction of perceived noise rather than an actual lowering of physically measurable noise levels.
• Optimum accoustic screening can be obtained by using earth mounds planted with vegetation, while built structures planted with vegetation can also be effective and require less space.
Influencing the hydrological cycle – stormwater management
Well planned and designed open spaces can have a considerable
beneficial impact on the hydrological cycle in urban areas.
• Properly planned and designed open spaces can provide important areas for the temporary storage of surface water during storm conditions until it can enter the drainage system.
• Open spaces with un-sealed surfaces can, in addition to storing storm water, allow it to infilrate directy into the ground thereby reducing the need for conventional piped drainage systems.
• Green open space with a significant vegetation cover can also intercept and temporarily store significant amounts of precipitation. This can either later be re-evaporated into the atmosphere, thereby contributing to maintaining atmospheric humidity, or be slowly released into the soil.
Providing habitats for wild plants and animals
The growing importance of urban open spaces as living space for flora and fauna was first remarked on in the late 1940s, in a study of the wildlife of suburban gardens in London.
• With the spread of increasingly intensive and industrialised agriculture rural habitats for wild plants and animals have become increasingly eroded.
• This has led to an increase awareness of the importance of the open spaces in towns and cities, both as refuges for species which would have otherwise survived in rural locations, as well as providing a range of habitat types unique to urban areas.
• Urban ecology and habitat mapping have become ways in which nature conservation approaches have spread to the urban environment.
• Abandonned land and derelict industrial sites also became seen as increasingly important potential habitats, initially for pioneer species and also for the development of characteristic urban plant and animal communities.
• In this context the linkage and connectivity of sites, both which each other and with the wider landscape, through a system of green wedges and ecological corridors is seen as vital.
Social and societal functions include:
Providing space and facilities for leisure and recreation
This is perhaps the best known function of urban open space and involves its direct use for play, sport and recreation, formal and informal, active and passive.
• Provision for play spaces for children of different age groups
• Provision for formal team sports of different kinds
• Provision for informal recreation not requiring special facilities (
Facilitating social contact and communication
Open spaces are a key part of the public realm and provide an essential arena in which people from different social, cultural and demographic groups meet and come into contact with each other. For this reason they must be seen as a central part of any strategy aimed at furthering social cohesion. Similar arguments were put forward for the creation of the first public parks in the early 19th century.
The Danish architect, Jan Gehl, identifies three levels of social interaction in public spaces:
• The first level of interaction results simply from the fact that people need to be in outdoor spaces
• The second level involves creating open spaces in which people choose to spend some of their free time
• Finally, only when people are making use of the opportunity to spend some of their free time in open spaces does the possibility of social interaction become available.
Optimum social interaction also requires a range of hierarchy of open spaces with a range of differing degrees of public through to private character. Particularly important in this context are spaces of a semi-private nature, which are accessible only to a clearly defined group e.g. the residents of a particular appartment block.
The interfaces between open spaces of different degrees of accessibility also offer an important means of exerting social control.
Access to and experience of nature
In contrast to the function of urban open space in providing habitats for flora and fauna, here the concern relates to the benefit of
It is argued that because human beings are a part of nature, and as a result of the species having evolved in interaction with its natural environent over millions of years, although we now overwhelmingly live in urban environments, we still need close and constant contact with the natural world. The so-called 'Biophilia Hypothesis' as put forward by E.O. Wilson is perhaps the best articulated example of this.
Influencing human physical and psychological health and well-being
Increasing evidence suggests that there are measurable health benefits which can be traced back to the presence of open spaces close to where people live and work.
Structural and aesthetic functions include:
These functions are of central importance for people’s perception of urban areas, but in most cases do not relate directly to the physical use of the open spaces in question.
Articulating, dividing and linking areas of the urban fabric
The role of urban open space in providing structure and organisation for an urban area is well established. In this way the town or city can be divided from the surrouding landscape, individual districts and land uses can be divided from one another and Such structural open spaces include green belts and concentric green rings, green wedges and green corridors as well as smaller green links, which may only take the form of tree-lined streets with low traffic levels.
Improving the legibility of the city
Being able to find one’s way in a city is of great importance for a wide range of reasons. This fact motivated the research which resulted in the classic urban design publication ‘The Image of the City’ by Kevin Lynch (1960). A clear sense of orientation is important both for reasons efficiency and in order to ensure a sense of well-being on the part of the population.
The five structural components of the urban environment identified by Lynch (landmarks, nodes, paths, edges and districts) are both scalable so that they can be applied at different levels of the spatial hierarchy, site, local, district, city-wide, as well as being applicable to the planning and design of open spaces.At a larger scale, individual open spaces of different kinds can also themselves represent different examples of Lynch’s structural components.
Establishing a sense of place
This function relates to the way in which parts of the urban structure are perceived
Acting as a carrier of identity, meanings and values
Open spaces as well as areas of the urban landscape as a whole are important carriers of meanings and values and help to create and reinforce individual and community identity.
This function can to some degree be influenced by the design of the spaces themselves, but the role of the way in which they are planned and the participation of the public in the design process is of considerable importance in this context.
Parks, public gardens and green spaces
• Local
• Neighbourhood
• District
• City
• Linear
Other green spaces
• Playgrounds
• Allotment gardens
• Cemeteries
• Sports grounds
• Camp sites
Roads and other transport routes
• Urban squares and plazas
• Pedestrian streets
• Residential streets
• Other roads
• Urban motorway corridors
• Car parks
• Cycle routes
• Railway lines and embankments
Residential open space and Housing landscape
• Private gardens
• Incidental open spaces in low-rise residential areas
• Communal open space in multi-storey housing
• Childrens’ playgrounds
• Roofs and balconies
Historic open spaces
• Formerly private parks and gardens associated with historic buildings
• Early examples of public parks and gardens which may have been restored and are protected for conservation reasons.
• Important protected view axes or corridors with historic significance
Waterbodies and water courses
• Rivers
• Canals
• Lakes
• Ponds
• Wetlands
External spaces in relation to buildings
• Schools and other educational institutions
• Offices, business parks and administrative buildings
• Hospitals and care homes
• Industrial estates and commercial buildings
• Other public buildingsMore recently the concept has been expanded to include those parts of the built fabric which are open to the sky, including roofs, terraces, balconies etc. and even building facades, where these can be clad with vegetation.
In addition there is a growing category of covered urban spaces which
As a consequence of this extended definition is important as urban open space can be seen as a continuous matrix of space within which all the built components of the city are situated, and which flows between and over the buildings, linking the urban centre with the surrounding peri-urban and rural landscape. As such it can be seen as representing an essential part of the basic infrastructure of all urban areas.
There is a simple assumption that public ownership is always associated with public accessibility and un-restricted use, but this must not always be the case. Different possible combinations of these factors need to be considered. It is important to remember that it is not only public spaces which can be influenced by public policy. There are a number of ways in which private spaces can also be influenced by planning regulations and public grants for example.
Functions of Urban Open Space
Understanding the varied functions of urban open spaces is an important part of helping to improve their effectiveness, both by enabling better management of existing urban spaces as well as improving the design of new ones.
There are many attempts to list these functions, but the following summary divides the functions up into three main groups:
• Environmental and ecological functions
• Social and societal functions
• Structural and aesthetic functions
Climatic a melioration
Open spaces can help to improve the climate of urban areas in a number of ways which are independent of the actions of people:
• Open spaces dominated by vegetation convert the solar radiation they absorb into sugars (photosynthesis) and therefore heat up less than adjacent areas, thereby helping to cool the surrounding air.
• The physical effect of shading by tree canopies and shrubs is also potentially a very significant one.
• The presence of cooler areas caused by green open spaces within towns and cities also helps to generate air movements as heavier cool air flows from cooler to warmer, more densely built up, areas.
• Evapo-transpiration from the vegetation also cools and moistens the surrounding air, something which is even effective in the case of relatively small open spaces.
• Areas of open water will also have a significant effect on reducing temperature levels overall, as well as of the fluctuations between day and night. This is a scaled down version of the oceanic climate effect.
• If open spaces are located in line with the direction of the prevailing winds this can help air circulation within the urban area – this if effective whether or not these spaces are dominated by vegetation, but with vegetation they can have additional benefits.
• Vegetation, especially belts of trees and shrubs, can be effective in removing particulate pollution from the air, as it becomes deposited on the leaves as the air-flow is slowed down by the vegetation barrier.
• A similar effect provides shelter from prevailing winds for people and dwellings located downwind. This can have a significant impact on the perceived climate and on the need for heating in buildings thus sheltered.
Noise screening
The effectiveness of open space in acting as a noise barrier is limited unless additional measures are taken. The impact of vegetation screening is small, but a combination of open space, earth mounding and planting can be an ideal solution.
• Green open space separating noisy land uses from ones requiring quieter conditions, can be effective in reducing noise levels in adjacent areas.
• This is more effective if they are characterised by dense tree and shrub planting, which can absorb noise to a limited extent.
• However, the major part of this effect is the psychological reduction of perceived noise rather than an actual lowering of physically measurable noise levels.
• Optimum accoustic screening can be obtained by using earth mounds planted with vegetation, while built structures planted with vegetation can also be effective and require less space.
Influencing the hydrological cycle – stormwater management
Well planned and designed open spaces can have a considerable
• Properly planned and designed open spaces can provide important areas for the temporary storage of surface water during storm conditions until it can enter the drainage system.
• Open spaces with un-sealed surfaces can, in addition to storing storm water, allow it to infilrate directy into the ground thereby reducing the need for conventional piped drainage systems.
• Green open space with a significant vegetation cover can also intercept and temporarily store significant amounts of precipitation. This can either later be re-evaporated into the atmosphere, thereby contributing to maintaining atmospheric humidity, or be slowly released into the soil.
Providing habitats for wild plants and animals
The growing importance of urban open spaces as living space for flora and fauna was first remarked on in the late 1940s, in a study of the wildlife of suburban gardens in London.
• With the spread of increasingly intensive and industrialised agriculture rural habitats for wild plants and animals have become increasingly eroded.
• This has led to an increase awareness of the importance of the open spaces in towns and cities, both as refuges for species which would have otherwise survived in rural locations, as well as providing a range of habitat types unique to urban areas.
• Urban ecology and habitat mapping have become ways in which nature conservation approaches have spread to the urban environment.
• Abandonned land and derelict industrial sites also became seen as increasingly important potential habitats, initially for pioneer species and also for the development of characteristic urban plant and animal communities.
• In this context the linkage and connectivity of sites, both which each other and with the wider landscape, through a system of green wedges and ecological corridors is seen as vital.
Social and societal functions include:
Providing space and facilities for leisure and recreation
This is perhaps the best known function of urban open space and involves its direct use for play, sport and recreation, formal and informal, active and passive.
• Provision for play spaces for children of different age groups
• Provision for formal team sports of different kinds
• Provision for informal recreation not requiring special facilities (
Open spaces are a key part of the public realm and provide an essential arena in which people from different social, cultural and demographic groups meet and come into contact with each other. For this reason they must be seen as a central part of any strategy aimed at furthering social cohesion. Similar arguments were put forward for the creation of the first public parks in the early 19th century.
The Danish architect, Jan Gehl, identifies three levels of social interaction in public spaces:
• The first level of interaction results simply from the fact that people need to be in outdoor spaces
• The second level involves creating open spaces in which people choose to spend some of their free time
• Finally, only when people are making use of the opportunity to spend some of their free time in open spaces does the possibility of social interaction become available.
Optimum social interaction also requires a range of hierarchy of open spaces with a range of differing degrees of public through to private character. Particularly important in this context are spaces of a semi-private nature, which are accessible only to a clearly defined group e.g. the residents of a particular appartment block.
The interfaces between open spaces of different degrees of accessibility also offer an important means of exerting social control.
Access to and experience of nature
In contrast to the function of urban open space in providing habitats for flora and fauna, here the concern relates to the benefit of
It is argued that because human beings are a part of nature, and as a result of the species having evolved in interaction with its natural environent over millions of years, although we now overwhelmingly live in urban environments, we still need close and constant contact with the natural world. The so-called 'Biophilia Hypothesis' as put forward by E.O. Wilson is perhaps the best articulated example of this.
Influencing human physical and psychological health and well-being
Increasing evidence suggests that there are measurable health benefits which can be traced back to the presence of open spaces close to where people live and work.
Structural and aesthetic functions include:
These functions are of central importance for people’s perception of urban areas, but in most cases do not relate directly to the physical use of the open spaces in question.
Articulating, dividing and linking areas of the urban fabric
The role of urban open space in providing structure and organisation for an urban area is well established. In this way the town or city can be divided from the surrouding landscape, individual districts and land uses can be divided from one another and Such structural open spaces include green belts and concentric green rings, green wedges and green corridors as well as smaller green links, which may only take the form of tree-lined streets with low traffic levels.
Improving the legibility of the city
Being able to find one’s way in a city is of great importance for a wide range of reasons. This fact motivated the research which resulted in the classic urban design publication ‘The Image of the City’ by Kevin Lynch (1960). A clear sense of orientation is important both for reasons efficiency and in order to ensure a sense of well-being on the part of the population.
The five structural components of the urban environment identified by Lynch (landmarks, nodes, paths, edges and districts) are both scalable so that they can be applied at different levels of the spatial hierarchy, site, local, district, city-wide, as well as being applicable to the planning and design of open spaces.At a larger scale, individual open spaces of different kinds can also themselves represent different examples of Lynch’s structural components.
Establishing a sense of place
This function relates to the way in which parts of the urban structure are perceived
Acting as a carrier of identity, meanings and values
Open spaces as well as areas of the urban landscape as a whole are important carriers of meanings and values and help to create and reinforce individual and community identity.
This function can to some degree be influenced by the design of the spaces themselves, but the role of the way in which they are planned and the participation of the public in the design process is of considerable importance in this context.
Catalogue of main types and categories of urban open space
Parks, public gardens and green spaces
• Local
• Neighbourhood
• District
• City
• Linear
Other green spaces
• Playgrounds
• Allotment gardens
• Cemeteries
• Sports grounds
• Camp sites
Roads and other transport routes
• Urban squares and plazas
• Pedestrian streets
• Residential streets
• Other roads
• Urban motorway corridors
• Car parks
• Cycle routes
• Railway lines and embankments
Residential open space and Housing landscape
• Private gardens
• Incidental open spaces in low-rise residential areas
• Communal open space in multi-storey housing
• Childrens’ playgrounds
• Roofs and balconies
Historic open spaces
• Formerly private parks and gardens associated with historic buildings
• Early examples of public parks and gardens which may have been restored and are protected for conservation reasons.
• Important protected view axes or corridors with historic significance
Waterbodies and water courses
• Rivers
• Canals
• Lakes
• Ponds
• Wetlands
External spaces in relation to buildings
• Schools and other educational institutions
• Offices, business parks and administrative buildings
• Hospitals and care homes
• Industrial estates and commercial buildings
Urban fringe
• Left over agricultural land
• Forests and woodlands
• Waste disposal and excavation areas
• Unplanned open spaces
Contact:
Nadácia Ekopolis / SlovakEnviromental Partnership
Manažérka programu PrieStory:
Martina Paulíková
Contact:
045 53317750915 811195
Email:
paulikova@ekopolis.skpaulikova@changenet.sk
Nadácia Ekopolis
Komenského 21
97401 Banská Bystrica