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Theme
1 Greenstructure patterns
The concept of greenstructure aims to promote a
comprehensive and strategic approach towards the planning
and management of all greenspaces in urban areas, regardless
of ownership status, greenspace type and function. Yet,
these tasks can only be successfully completed if based on
good knowledge of the city's greenspace resource, its state
and condition as well as the factors which have shaped and
continue to shape the greenstructure.
Part 1: Comparison of
greenstructure patterns
This is but a first
attempt to bring together the different case studies. Most
of the following is still rather a description than a real
analysis. This description is often rather patchy and you
will probably find that your case study area was not well
characterised or is missing in places where it should have
been mentioned. I may have overlook relevant information
when going through the different case studies. Therefore, I
very much hope you can improve this part in filling the gaps
and putting wrong descriptions right. Most of all, I hope
you can help by telling us what you expect from this part,
what you think should be discussed and where the conclusions
should lead to.
One area, I would find
interesting is to find more out about is whether and how
urban planning and greenspace planning have influenced the
spatial greenstructure of the case study areas. Are there
policies/ plans for spatial planning of the greenstructure
such as the greenfinger plan? Are there others? To which
levels of urban planning &endash; regional, city,
neighbourhoods &endash; do these plans apply? Which
arguments were used for suggesting these plans (e.g. mainly
as a barrier to urban development such as green belts? For
aesthetic reasons, recreation or nature conservation, e.g.
to increase connectivity between habitats?; Were these
successfully implemented? What are the limitations of these
concepts? Can you aid us here?
What
should be highlighted/ discussed in the final
part?
Introduction
The objective of this
chapter is to characterise and compare the greenstructure of
the case study areas, in order to identify both common and
distinctive features and analyse how these relate to natural
and cultural conditions as well as urban planning. To this
end, the chapter will address the following
questions:
- Can greenstructure
patterns be distinguished? What are the elements of the
greenstructure of the case study areas?
- How has the
greenstructure been shaped by natural and cultural factors,
and urban development?
- How does the
greenstructure relate to urban density?
- How does the
greenstructure change? (I have added this as a new
question)
Greenstructure is
understood here as the composition and spatial pattern of
urban greenspaces and surface waters, whereas greenspace is
broadly defined as all open space within the boundaries of
the municipality which is actually covered by vegetation or
areas where vegetation can instantly develop such as bare
soils. Open space is a wider category to include all space
not covered by buildings, including greenspaces and water
surfaces but also all paved spaces such as paved squares,
roads, and car parks.
1 General information on
greenspace in European urban areas
As a background for the
comparison of the case studies, I thought it might be useful
to provide some general figures on greenspace provision in
European urban areas. This part is a bit lengthy but can be
shortened.
Few studies are
available that provide comparable figures for greenspace
cover of European urban areas. Gälzer (1987) compared
21 large European cities and towns based on a common method.
In this study, the proportionate cover of greenspace was
measured from existing land use maps for the inner city (up
to 5km from the city centre), the intermediate urban area
(5-10km from the city centre), and the urban fringe (over
10km from the city centre but within municipal boundaries).
Greenspace was classified using a common key to enable
comparison between urban areas.
A limitation of this
method was that only distinct greenspaces were taken in
account (including farm- and woodland). On the other hand,
the cover of greenspace within urban land uses such as
residential areas or commercial estates was not measured.
The results from this study show:
· The overall cover of
greenspace (including farmland, woodlands) and surface
waters within the municipal boundaries varies between 32% in
Brussels and 61% in Hannover.
· Provision of amenity
greenspace (defined here as areas for recreation, parks,
allotments, playing fields, and cemeteries) can also greatly
vary between urban areas. Overall, the cover of amenity
greenspaces varies between 6.4% in Lyon and 27.0% in
Cologne. In the inner city of Lyon (0-5km from city centre),
these greenspaces cover 3.7% of the surface area, whereas
they cover 19.9% in Cologne. Similar differences could be
observed in the intermediate zone (5-10km from the town
centre).
· The percentage of
greenspace types can vary greatly between urban areas. For
instance, parks only have a share 1.6% of all greenspace in
Zurich whereas they comprise 44.8% of all greenspace in
Rotterdam. In cities bordering the sea, such as Rotterdam,
Amsterdam and Copenhagen, water surfaces form a significant
part of the greenstructure.
· There is usually a
clear gradient from the inner city, where green space
provision is generally low to the urban fringe zone where
green space provision is much higher. In Vienna, for
instance, overall proportionate cover of greenspace and
surface waters rises from 22% in the inner city, to 54% in
the intermediate zone to 83% in the urban fringe. Yet, the
gradient can be also quite small as is the case in Belgrade
where greenspace covers 54% in the inner city, and this
cover rises to 60% in the urban fringe zone.
Data on the greenspace
provision of urban areas can also be found in environmental
reports of the European Environment Agency (EEA 1995 &
1999a,b). This data includes 50 urban areas. Acccording to
these figures, the percentage of the population with access
to urban greenspace within a fifteen minutes walking
distance can greatly vary. While in some cities all people
have access to public greenspace within 15 minutes walk from
where they live, the percentage can be as low as 50% for
Venice and 47% for Kiev (EEA 1995). (The statistical
compendium includes Helsinki, Oslo, Warsaw, Vienna,
Sheffield, but not Munich, Herning, C. Budejovice,
Utrecht).
Only summary figures for
overall provision of public greenspaces were given. These
range from only 4% in Athens (Greece) to 53% in Budapest
(Hungary) (EEA 1999a,b) but differences may partly be
explained by the varying amount of countryside around the
cities included within municipal boundaries.
On the other hand,
farmland and woodlands on the urban fringe equally need to
be considered as part of the urban greenstructure as the
distinction between urban areas and surrounding countryside
has lost its meaning in city regions. A survey recently
undertaken for the European Environment Agency (Moland
project; EEA 2002) estimated for the first time the
proportionate cover of different land uses in city regions
based on methods which allow comparison between urban areas
(Annex 1). Agricultural land and areas classified as natural
ranged from a proportionate cover of 22.4% for the large
Ruhr conurbation (Germany) to over 75% for Dresden
(Germany), Tallinn (Estonia) and Algarve (Portugal). The
average cover for all 24 urban areas was 53%.
According to these
figures, the proportionate cover of distinct urban
greenspaces can range from 0.6% to 16.3% (Fig. 1).
Greenspace provision appears neither to be related to the
size of urban areas nor to population numbers. A geographic
pattern can be observed as greenspace provision tends to be
lower in southern cities. On average greenspaces cover 3.8%
of the urbanised area in South European cities (1 in Fig.
1), whereas they cover 6.0% in Central European cities (2 in
Fig. 1, N=11), and 10.6% in North European cities (3 in Fig.
1, N=5).
Fig. 1: Percent of green
urban area within the total urbanised area (based on data
from: EEA, 2002)
Summary:
- Information is rare
allowing comparison of the greenspace provision and
spatial patterns in European urban areas.
- Where data on
greenspace provision exists, it shows the large
difference in proportionate greenspace cover and
greenspace composition between cities and
towns.
- The greenspace
resource ranges from urban parks and other amenity
greenspaces to farmland and woodlands, as well as surface
waters.
- Generally, a clear
gradient of greenspace provision exists from the inner
city ot the urban fringe.
- Greenspace provision
appears neither to be related to the size of urban areas
nor to population numbers However, there seems to be a
gradient of greenspace provision from low levels in
southern cities to higher levels in Nordic
cities.
2. The pattern of
greenstructure in the case study areas:
2.1
Introduction
The selected case study
areas are mostly larger cities with a population size
between 510,000 residents (Oslo) to 1.6 million residents
(Vienna). However, the city region is usually much larger
than the city itself. The survey also includes a medium
sized town (C. Budejovice, 100,000 inhabitants) and the
small town of Herning, Denmark (...residents). Cities across
Europe are included (Fig. 2) but a Mediterranean city is
missing. Most of the cities included have a long history and
comprise a historic centre. Sheffield is an example of an
old-industrialised city struggling with economic problems
and population numbers in decline, whereas Helsinki, Oslo
and Munich are examples for growing cities where the economy
is based on services and high-tech industries. Warsaw is an
example for a city in a former East bloc country.
Fig. 2: Case studies
(Location map)
Anne to
add
Overall, the case
studies cannot be considered as representative of all urban
situations in Europe but they comprise a fair range of
different urban types, geographic locations and
socio-economic conditions. Table 1 contains some summary
figures to characterise the case study areas.
Can you
please send the correct figures to
Anne
Table 1: Some general
figures on the case study areas. Percentage figures can be
added later.
1) source: LH
MÜNCHEN 1991
2) owned by the
municipality or the Bavarian state, including parks,
cemeteries, avenues, allotment gardens as well as greenspace
around schools and other public buildings source: Ammer and
Ritter, 1990
3) parks, cemeteries,
allotments, playing fields
4) parks, avenues and
squares, cemeteries, allotments, botanical garden
5) including water
surfaces, as well as greenspace in urban land uses such as
residential areas; excluding impervious surfaces.
2.1 Can
greenstructure patterns be distinguished? What are the
elements of the greenstructure of the case study
areas?
Greenspace covers larger
areas in the cities than built and paved spaces. In Vienna,
only 32.8% of the city is classified as built-up, whilst
greenspaces cover 48.8% of the city's surface area when
farmland and woodlands on the urban fringe are included.
Similarly, two thirds of Oslo's surface area consist of
woodlands and farmland. In other cities, the proportionate
cover of greenspaces can be considerably lower. According to
land use statistics, the proportionate cover of greenspaces
is below 40% in Munich. However, the figures are difficult
to compare as the proportionate cover of greenspace varies
depending on how much of the surrounding countryside is
incorporated within the municipal boundaries. Figures on the
greenspace provision within the city region generally do not
exist for the case study areas.
The figures for
greenspace provision do not yet take into account the
greenspace as a part of the different types of urban land
uses such as residential, commercial and industrial areas as
well as the different transport corridors. Figures were only
available for Munich where greenspace covers more than 60%
of the total area of the city when all greenspaces are taken
into account. Within the built-up area, greenspaces still
cover 21% of the area. These figures are considerably higher
than the figures provided in the European survey prepared
for the European Environment Agency (EEA 2002) where the
proportionate cover of greenspace within Munich's urbanised
area was estimated to be 8.6%. In this survey, only distinct
greenspace categories were measured but not greenspace
within urban land uses.
The urban greenspace
resource is composed of a variety of greenspace types. These
include natural areas such as woodlands or wetlands,
productive farmland as well as different types of amenity
greenspaces as well as transport corridors. The percentage
cover of the various greenspace types can vary largely
between cities, and this gives local distinctiveness to the
urban area. For instance, in Oslo and Helsinki woodlands
predominate. Water is also an important component of the
greenstructure in cities bordering the sea such as Oslo and
Helsinki. Rivers are part of the greenstructure in Vienna,
Munich, C. Budéjovice and Utrecht.
Ownership structure can
be assumed to be equally complex, including a range of
public bodies and different types of privately owned land.
The amount of public greenspace can differ largely. There
were no figures available to directly compare the case study
areas but in Helsinki, for instance, 76% of the total
surface area is owned by the city or by the state. In
Munich, on the other hand, public greenspace covers appr.
10% of the surface area.
The amount of natural
greenspace in the cities can be significant. Natural
greenspace covers 11% of the city surface area in Munich.
These natural greenspaces cover almost the same area as
designated greenspaces such as parks and squares (some
overlap occurs as a number of natural areas within parks
were also mapped in the habitat survey). In Oslo, even two
thirds of the municipal territory are covered by woodlands
(can these be considered as natural in a broader sense?
Purely commercial plantation forests should be excluded).
Other cities (data ?).
Can we arrive with a
rough comparison of natural greenspace in the case study
areas? Data from habitat surveys would help.
Finally: different
accessibility of greenspace might be interesting to
highlight. For instance, in Helsinki woodlands and other
natural areas are freely accessible. This is also the case
in Munich. How is the situation in your case study area? Are
significant parts of the greenspaces not accessible or is
access restricted/ conditional (e.g. entrance fees). How
well is the countryside around the towns
accessible?
Figure 3 suggests that
different spatial patterns of green might be distinguished
on different spatial levels between and within the case
study areas. These greenspaces patterns reflect the
influence of natural and cultural features as well as
efforts to create new urban greenstructures.
Fig. 3. Greenspace
pattern in the case study areas.
Anne to
add
Summary:
- The greenstructure
of urban areas was analysed on the level of the city
region, the city as well as within the built
areas.
- The percentage cover
of greenspace in the case study areas is higher than that
of built and paved areas when greenspace in urban land
uses such as residential areas as well as farmland at the
urban fringe is included. Greenspace in residential areas
can be quite high but is normally not considered in land
use statistics.
- Data on greenspace
provision in the city region generally does not
exist.
- The composition of
greenspace can be diverse and differs between the case
study areas. In particular the variety of natural
greenspaces contribute to this diversity. Ownership
status, management and types of use can be assumed to be
equally complex.
- The amount of
'informal' greenspaces can be as high as 'formal' public
greenspace.
- The case study areas
have distinct spatial patterns of greenstructure on the
level of the city region, the city and urban zones within
the city. These patterns are influenced by natural
features, city history and recent planning.
2.2 How has the
greenstructure been shaped by natural features, city history
and urban planning?
Natural and cultural
features of the urban greenstructure:
Water, especially
streams, are particularly important because they often form
the only continuous green corridor within the built-up area
(e.g. Warsaw, Vienna, Munich, C. Budéjovice).
Moreover, they link greenspace in the city with the
surrounding countryside. In Helsinki, the sea is a major
part of the greenstructure. There are almost 100 kilometres
of shoreline and over 300 islands in the Helsinki
archipelago. However, not only surface waters can influence
the greenstructure of a city. In Munich, extensive wetlands
remained as open space on the fringe in the north and east
because they formed a natural barrier to settlements until
recently.
Terrain is the other
important natural feature of urban landscapes that has an
influence on greenstructure. For instance, hills covered by
woodlands surround Oslo. Greenspace was preserved and
created on the steep escarpments and river terraces through
Warsaw and Munich. In Helsinki, the 'green fingers', i.e.
green corridors from north to south, were preserved on
agricultural land, river valleys, rocky ridges with spruce
swamps and other wetlands, which formed a natural barrier to
urban development.
Natural factors also
largely determine the diversity of urban greenspace. In
Munich, for instance, twelve habitat types could be
distinguished. These types range from remnants of natural
woodlands and cultural landscapes such as dry meadows to
typical urban habitats such as extensively managed parts of
parks and industrial wastelands.
Natural greenstructure
was often ignored in urban planning, and therefore destroyed
where they did not form strong barriers to urban
development. As a consequence, natural greenspaces are often
small, fragmented and isolated. The remnants of natural
woodlands in Munich are split up into 153 woodlands, with
the average size being below 5 ha. Another example is Oslo
where small streams in Oslo were largely built
over.
Cultural landscapes can
equally be an important element of the urban greenstructure.
All cities comprise farmland on the urban fringe. Vienna's
greenstructure comprises also vineyards. These cultural
landscapes are often threatened by urban expansion and
impoverished by intensive farming practices.
Historic parks and
related features such as canals are an important
greenstructure, for instance in Vienna, Munich and Warsaw.
These parks could be connected by linear greenstructures
such as avenues and canals. The former ring of
fortifications around the city was sometimes fully or partly
converted into greenspaces (e.g. Vienna). Moreover,
woodlands and parklands were often protected as hunting
reserves and for game keeping. Originally, the parks were
created outside the city but have later become surrounded by
built areas. Thus, they are rather a present made to the
city than an achievement of urban planning
itself.
In particular the very
dense developments of the late 19th century and early 20th
century are characterised by low levels of greenspace
provision. Vienna and Munich, for instance, lack in large
parks in the inner urban zones. Urban zones of this time are
characterised by a lack of a spatially coherent
greenstructure. In Munich new large parks were only created
from the 1970s onwards as part of major urban
extensions.
The development of
transport corridors has also had an impact on the
greenstructure of the cities, e.g. in Helsinki, Munich and
Warsaw. In particular main railway lines can form barriers
to urban development and leave wedges of open spaces within
the built area. While these areas are not accessible, they
may still have important ecological and environmental
functions (e.g. ventilation). They can be converted into
green corridors when the railway lines get out of
use.
Planned urban
greenstructure: (still quite patchy)
Particular policies,
which influence the provision and spatial pattern of the
urban greenstructures in the case study areas,
are:
- Greenspace
protection: In Vienna, for instance, the Wienerwald west
of the city was designated as a protected area.
Similarly, the woodlands surrounding Oslo were strictly
protected.
- Spatial strategies:
'Greenfinger plans' were adopted in Helsinki and Warsaw
to preserve a link between inner city green spaces and
the surrounding countryside through green wedges. These
green corridors provide a strong spatial protection/
definition of greenstructure, however, they are less
successful in defining the quality/ content of the
greenstructure (True?). City ventilation was the main
argument for creating the green fingers in
Warsaw.
The concept of the Green
Poster is used in Oslo as a tool serving as a "green warning
signal" for planners and contractors. Based on several part
studies of recreational, -landscape and biodiversity data
the Green Poster is a synthesis and a strong recommendation
highlighting the crucial green structure. It identifies the
need for recreation corridors and wildlife corridors. The
concept of greenbelt is used in Vienna to protect the
countryside around the city. Greenbelts are also shown in
the regional plan ifor Munich, however, these greenbelts for
not have the status of legally protected areas.
The 'Urban Natural
System' is a concept used in Warsaw for greenstructure
planning. It divides the city into three main zones. These
are the Ecological Zone, Ecological Zone- Auxiliary System
and Air Ventilation and Regeneration System. The main role
of the Ecological Zone &endash;Auxiliary System is to keep
connectivity between green areas or to buffer natural
greenspaces.
In Munich, a habitat
corridor strategy was prepared as part of a nature
conservation programme. This strategy has been incorporated
into the urban development strategy, and is complemented by
a strategy to create linkages between greenspaces from a
recreation perspective. The strategy is intentional and can
only be implemented through integration into the land use
plan. Similarly, the Network of Landscape Systems of
Ecological Stability (ÚSES) is used in C. Budejovice
to plan networks of natural areas.
- Greenspace
hierarchies: often in connection with greenspace
standards to provide greenspace on different levels of
greenspace provision, from the city down to the
neighbourhood level. Greenspace standards are usually
selective to particular greenspace types, e.g. play
areas, and only prescribe the quantitative provision of
these greenspaces. Greenspace standards do not give much
consideration to the spatial pattern of greenspaces.
Difficult to assess on basis of the case studies how much
these have influenced the spatial pattern of
greenstructure in the case study areas.
- To create new
greenstructures in combination with large development
projects. An example is the creation of the river Danube
island in the heart of Vienna. The project was driven by
river engineering for flood protection but greenspace
planning was successully integrated to create the largest
park in the city. The conversion of the former airport in
Munich is another example. One third of the overall area
is dedicated to public greenspace.
- Land
ownership/control is an important factor for
greenstructure planning. For instance, the City of
Helsinki City owns 69 % and the state some 7 % of the
city's land, and the city is also the largest owner of
green areas, and this has enabled the protection of the
green fingers. (True?). Similarly, the land on which
Messestadt Riem is built, including the park, is owned by
the City of Munich.
Summary:
- In all case study
areas, natural and cultural features significantly
influence the greenstructure, ist spatial pattern and
composition.
- Main natural factors
influencing the spatial greenstructure are rivers
(floodplains) and terrain.
- Historic parks,
hunting forests etc. can form an important component of
the greenstructure. While the parks were mostly created
outside the cities, they have become incorporated
subsequently.
- On the city and city
regional level, a range of concepts could be identified
to plan for spatially coherent greenstructures. These
comprise greenfinger plans in Helsinki and Warsaw,
greenbelts in Vienna (and Munich), the Urban Natural
System in Warsaw, and concepts of ecological networks in
Munich and C. Budejovice.
3.3 Does a relation
exist between urban density and greenspace
provision?
From the data of the
European survey undertaken for the European Environment
Agency, a relation between overall urban density and the
provision of urban greenspace within the urban area cannot
be confirmed. This is due to the lack of data on building
density, on the one hand, and greenspace cover, on the
other, within the urbanised area.
The case study areas
could not be ranked according to a measure of urban density
in order to explore the relationship with their greenspace
provision. However, an inverse relationship between urban
density and greenspace cover exists on the city level. Urban
zones can be distinguished that differ with respect to
predominating land uses and building densities. Densely
built zones have a low green space provision whereas
low-density areas have a better provision of greenspace when
private greenspace is included.
In Munich, greenspace
provision was estimated for urban morphology types.
Single-family residential areas had a cover of greenspace of
over 20%, whereas densely built-up inner blocks, industrial
areas and large roads have a cover of less than 5%. A clear
relationship could be established between building density
and greenspace provision for residential areas and
indstrial/ commercial areas, respectively. When built areas
covered 10-20% of the surface area, mean vegetation cover
was above 70%. When built areas covered 50-60% of the
surface area, the vegetation cover dropped below 10%. In
industrial and commercial areas, a similar relationship
could be established but the level of greenspace cover is
generally much lower than in residential areas. The reason
is that much of the open space is paved.
Exploring the
relationship between urban density and greenspace provision,
on the one hand, and how this affects the environmental
performance of urban areas, would be welcome to balance the
goals of developing compact cities with the goal to maintain
and improve environmental quality within urban
areas.
Summary:
- There is a lack of
data to explore the relation between greenspace provision
and urban density on the level of the city region and the
city.
- Within urban areas
all case studies show a clear pattern of urban zones,
from the densely built-up inner city to the urban fringe
where the provision of greenspace is inversely related to
the building density.
3.4 How does the
greenstructure change?
While the case studies
do not provide figures, it is quite likely that the overall
greenspace balance is negative in all case study areas. In
city regions, pressure on greenspace is generally strong.
The survey undertaken for the European Environment Agency
reveals that between 7.3% and 41.3% of areas classified as
agricultural or natural where converted to urban land uses
from 1950 &endash; 1990. On a more detailed level, the case
studies show, that both outside and within urban areas
greenspaces are lost and continue to become lost due to
urban development. The main consequences were detailed in
the Oslo case study as:
- A loss of overall
greenspace area
- An increase of the
overall number of greenspaces, as well as the number of
small greenspaces due to fragmentation
- A loss of large
greenspaces
- The isolation of
greenspaces
Data from a study in
Munich also show that pressure on residential greenspace can
be high due to infill densification of low density
residential areas (Wagner 1989). There is both a loss in
overall cover of greenspace and in particular trees. A
recent survey in Merseyside brought further evidence and
assessed the negative environmental consequences (Pauleit et
al., in prep.).
However, new greenspace
can also emerge in the form of derelict land (e.g.
Sheffield). Yet, these greenspaces are often negatively
perceived as 'brownfields' whereas their potential for
improvement of the urban environment in a wider sense is not
fully recognised.
The quality of both
public and private greenspace can also change by the lack of
adequate management. However, there was no information
available to assess the extent of theses changes. In large
high-rise developments, in particular the ones built in
Warsaw and C. Budejovice, greenspace was often not created
and managed as planned, and therefore, is of poor
quality.
Summary:
- In all case study
areas is lost due to urban development. Main losses occur
in particular at the urban fringe/ in the city region,
however, greenspace within urban areas is also lost due
to infill densification. In particular the value of
derelict land is not recognised in urban
planning.
4 Discussion (at the
moment only some points for discussion)
The chapter has
attempted to characterise main features of the
greenstructure in the case study areas. Main results were
that:
All case study areas
contain a large amount of greenspace which can be even
larger than the cover of built and paved surfaces.
Greenspace within urban land uses such as residential areas
isan important part of the overall greenspace resource. The
greenstructure of a city is a continuum of different types
of greenspaces, and different amounts of greenspaces. These
have different different appearance, qualities, functions,
management and ownership. Results from the case studies show
that a large proportion of this greenspace can be considered
as informal (non-designated, non planned)
greenspace.
The spatial pattern of
greenstructure and its composition in terms of greenspace
types differs greatly between the case study areas. It is
influenced by natural and cultural factors as well as
strategies for urban planning.
o Strong natural
barriers to urban development such river floodplains or
steep slopes were most effective in creating spatially
coherent greenstructures. In some cities also historic
systems of parks, connected by canals and avenues do exist.
o Urban planning, on the
other hand, has often failed to achieve the creation of
spatially coherent greenstructures during times of strong
urban growth. Greenfinger plans are in Helsinki and Warsaw
are an exception. However, some cities have adopted
strategies for the creation of ecological corridors (Oslo,
Helsinki?, Munich, Warsaw, C. Budejovice). Are these
implemented?
Greenspace standards, on
the other hand do not consider the spatial configuration of
greenspace.
- - How do the cities
assess their greenspace resource and its functions?
- - Is the importance
of greenstructure reflected in the role of greenspace
planning and management in urban areas?
- - Which policies are
there to influence the composition and management of
greenstructure? Standards?
- - Do policies
consider all greenspace types, including the informal
greenspaces?
- - The greenstructure
needs to be planned at different levels: city region,
built area, and urban zones. Does urban planning take
into account the different levels of greenstructure and
by which means is this achieved?
- - What is the
relevance of the spatial pattern of greenstructure to
their ecological and environmental functions?
- - Can spatial
concepts of greenstructure planning be assessed on basis
of their environmental/ ecological
performance?
Ammer, H., Ritter, G.,
1990. Öffentliche Grünflächen und Wald. In:
LH München (Eds.) Umweltatlas München, see
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EEA (European
Environment Agency), 1995. Europe's Environment. The Dobris
Assessment. European Environment Agency,
Copenhagen.
EEA (European
Environment Agency), 1999a. Environment in the European
Union at the turn of the century. Office for Official
Publications of the European Communities,
Luxembourg.
EEA (European
Environment Agency), 1999b. Europe's Environment:
Statistical Compendium for the Second Assessment. Office for
Official Publications of the European Communities,
Luxembourg.
EEA (European
Environment Agency), 2002. Towards an Urban Atlas.
Assessment of Spatial Data in 25 Cities and Urban Areas.
Environemtnal Issue Report No. 30. EEA,
Copenhagen.
Gälzer R, 1987.
Vergleich der Grünsysteme Europäischer
Großstädte mit jenem von Wien. Wissenschaftliche
Studie i.A. der Magistratsabteilung 18 -
Stadtstrukturplanung. Beiträge zur Stadtforschung,
Stadtentwicklung und Stadtgestaltung 17, Wien (In
German)
Maurer L., Meindl P.,
Erhart E., Forster A., Hartl W., Kienegger M., Kromp B.,
Weber G., Auer N., Meyer-Cech K., Seher W., Hüttler W.,
Fischer-Kowalski M., Nicolini M., Amann C., Gindl M.,
Krausmann F., Blaas W., Stoiss C. (2000): Optionen für
die Entwicklung von Landwirtschaft und Gartenbau in Wien. 1.
Zwischenbericht - Darstellung des Status Quo. Im Auftrag von
Bundesministerium für Wissenschaft und Verkehr und
Magistratsabteilung 22 - Umweltschutz.
Statistical
Review-Warsaw (2002) Information and Statistical Papers,
Year XI No 1/2002, Warsaw.
* Vandermotten, C (1994)
Comparative Atlas of Major European Cities.
Université Libre de Bruxelles (ULB), Brussels.
Contains city maps of population densities. Quoted in EEA
1995, Chapter 10.
Annex 1: Methods used
in the Moland/ Murbandy project
Satellite imagery and
aerial photography were used to assess urban land use change
in a recent study for the European Environment Agency
(Murbandy/ Moland, EEA, 2002). 'The area of investigation
was selected on the basis of the contiguous artificial
surface &endash; core area &endash; of the city centres,
plus a peri-urban buffer zone' (EEA, 2002, p. 41). The width
of the buffer zone was calculated as a ratio of the surface
core area (A) (Buffer zone width = 0.25 x ĆA). Until now,
data has been collected for 25 urban areas and six extended
areas. In this study, EU's Corine land cover classification
was extended to allow for a distinction of up to 51 land
cover/ land use classes. Greenspaces within the urban fabric
such as parks and cemeteries were classified as 'green urban
areas'. Further open space categories include abandoned land
within urban areas, sport and leisure facilities, and water
courses. Several classes of agricultural land uses and
woodlands were also distinguished whilst greenspace within
urban land uses such as residential areas was not
measured.
Annex 2: Summary of
case studies
1 The greenstructure
of Oslo
Provision and spatial
pattern of greenspace: Oslo is a compact yet low density
city. Overall, greenspace provision appears to be quite
high. Over 90% of the population live within 15 minutes
walking distance from public green space (EEA 1995).
Figure 3. The share of
main nature types in the municipality of Oslo. Source:
Recreation and Leisure Service. Oslo City
Located at the Oslo
Fjord, water forms an important element of Oslo's
greenstructure. There is a clear distinction between the
built area and the woodland belt surrounding the city. The
woodland belt covers two thirds of the municipal territory.
These coniferous woodlands are of great importance for
recreation but also for nature conservation. Within the
city, the greenstructure consists of public parks. These are
dispersed throughout the city but mostly not connected one
to the other. Streams would be natural links between the
greenspaces, but these have mostly been culverted.
In addition to
designated greenspace, residential greenspace forms an
important part of the city's greenstructure as most
residential areas have a low density.
Greenstructure change:
Whilst the woodland belt is strictly protected, pressure on
greenspaces by development is high within the built areas
and on farmland at the urban fringe. These farmlands have
some of the best soils in Norway. Urban development within
the city has led to the fragmentation of the greenstructure.
50% of greenspace areas have been lost between 1950-1990.
The Green Plan (Oslo Municipality 1993) and the Green Chart
(Oslo Municipality 1997) have been introduced as strategies
to reverse these trends.
Influence of natural and
cultural factors on the greenstructure: Woodlands and
wetlands are the dominant nature types of Oslo (Fig. 3).
While the city developed in the plain facing towards the
fjord, the woodland belt was preserved on the hills
surrounding the city, and is now strictly protected.
However, the water network within the city has not been
given equal status, and therefore most of the streams have
been built over.
2 The greenstructure
of Helsinki
Provision and spatial
pattern of greenspace: Helsinki is the capital and largest
city in Finland. The urbanised area of the city covers not
only the municipality of Helsinki (with about 550,000
inhabitants) but also two other large municipalities (Espoo
and Vantaa) with about 200,000 inhabitants each. Helsinki's
municipal territory covers 185 km2 of land area and 500 km2
of sea area. Due to strong internal migration during the
last decade, Helsinki and Helsinki region are presently one
of the fastest growing urban regions in Europe.
Greenspace composition:
table 2 provides figures of the percentage cover of habitat
types in built areas and in greenspace, respectively. This
is interesting but can you also provide an overall figure?
E.g. what is the overall percentage share of mires among the
habiat types?
As Helsinki City owns 69
% and the state some 7 % of the land within the
municipality, Helsinki is also the largest owner of green
areas About one third of the entire area of Helsinki was
desginated as greenspace in 1998, which corresponds to
approximately 100 m2 of greenspace per inhabitant. Public
urban forests cover 63% of this green space. Otherwise it
consists of built parks (17%), manor estates (1%) and
meadows and landscape fields (11%).
Spatially, the two most
important features of Helsinki's greenstructure are the
'green fingers' reaching from north to south into the city
centre, and the Baltic sea.
As Helsinki City owns 69
% and the state some 7 % of the land, Helsinki is also the
largest owner of green areas.
Greenstructure
change:
Main pressures on
greenspace are? Do you have information on greenspace
change? Can you summarise this from your table 2? Are these
real losses or &endash; as I understand it &endash; proposed
changes?
Influence of natural and
cultural factors on the greenstructure:
The landscape of
Helsinki is dominated by glaciofluvial landscapes, exposed
bedrock and forested hills alternating with flat clay areas
which once constituted the seabed. The city centre is
situated on a rocky peninsula near the open sea. The
shoreline is long and there are hundreds of islands, most of
which are small rocky outcrops from the sea. Inland the
landscape scenery is dominated by granite hills (30-60 m
above the sea level), mixed with sites with gneiss,
amphibolite and limestone, cliffs and tiny canyons.
The geographical
location of Helsinki on a narrow peninsula has had a
significant influence on its urban and green structure.
Because of the topography of the region, and the historical
possibilities of the city to expand, there are long
stretches of green from the north that penetrate deep into
the centre of the city. Most of the these present main
continuous radial green areas, the so-called green fingers
of Helsinki, are a mixture of former agricultural river
valleys, rocky forested ridges with spruce swamps and other
wetlands, that had former geotechnical and economical
threshold for construction.
Regional planning took
the lead in recreational and nature conservation planning in
the 1970´s: regional green area structure and
nationally status-given conservation areas. Central park
(one of the main green areas, the so-called "green fingers"
of Helsinki) is the first to gain legal status in a local
general plan in Helsinki in 1978.
3 The greenstructure
of Munich
Provision and spatial
pattern of greenspace:
Munich is at the centre
of a fast growing urban region. The city itself is already
densely built-up but pressure on open space continues to be
strong. In 1987, public greenspace covered 3192 ha (Ammer
and Ritter, 1990). This corresponds to 10% of the city
surface, and a per-capita greenspace provision of
approximately 25m2 (including greenspace on school grounds
and other public institutions).
These figures only refer
to public greenspaces. A survey revealed that within the
built area (i.e. excluding farmland on the fringe), 21% of
the city is covered by greenspace. A significant proportion
of this overall greenspace resource is to be found in
residential areas and other land uses. The natural
greenstructure (including areas on the urban fringe) covers
approximately 10% of the city's surface area. It mainly
consists of woodlands, extensively managed grasslands, and
wastelands. Overall, informal (natural) greenspace as mapped
in the habitat survey, covers almost the same area as public
greenspaces in the city.
The distribution of
greenspace in the city follows a pattern of concentric
rings, where the densely built up inner city with a low
provision of greenspace is surrounded by a broad belt of
medium and low density residential areas with good provision
of greenspace in private gardens. Industrial and commercial
areas form clusters within this belt. These are concentrated
in particular in the northern part of the city and have a
low provision of greenspaces.
The floodplain of the
river Isar forms the green backbone of the city, connecting
woodlands and parks from south to north. Other large parks
and cemeteries can be found in the ring around the inner
city. These are surrounded by other land uses and are not
connected one to the other. Overall, there is a particular
lack of a green linkages from east to west. The city did
also not manage to retain the former walls around the
historic city centre as a green ring but this is today a
ring road.01758933947
Greenstructure
change:
Munich's greenstructure
is under strong pressure from urban development. While
public greenspaces and woodlands are overall now well
protected, in particular the natural greenstructure of
extensive grasslands and wastelands is at risk from further
destruction and fragmentation.
The strongest
development occurs outside the city in the northern Munich
plain. While the area north and north-west of the city is
already characterised by large urban and suburban
developments, it is now the fenland area in the north-east
where the development is particularly strong. The location
of the new airport 35 km north of the city centre has
further heated development pressures. As a consequence, the
former rural landscape is transformed into a city
region.
The city aims, on the
other hand, to create new public greenspace and a green
network as a part of big urban projects such as the
redevelopment of the former airport at Riem.
Influence of natural and
cultural factors on the greenstructure:
Munich is situated in a
plain where natural constraints for urban development are
few, with the notable exception of the river Isar
floodplain. This is reflected in the spatial pattern of
greenstructure as described above. However, Munich still has
an important heritage of natural greenspaces, reflecting the
fine grained pattern of natural units in the city. These
largely contribute to the city's biodiversity.
Munich has also an
important heritage of remnants of the cultural landscape and
historic parks which determine the greenstructure of the
city.
4 The greenstructure
of Vienna
Provision and spatial
pattern of greenspace:
Vienna is a large city
of approximately 1.6 million inhabitants. According to land
use statistics, only
Greenspace covers nearly
half of the surface area of Vienna of 415km2, including a
broad range of greenstructures, from small neighborhood
parks, green spaces along streets and in courtyards, trees
and avenues to large historic parks, nature conservation
areas and the urban forests at the fringe of the city. More
than one third of the green space is covered by woodlands,
another third is farmland (arable land, horticultural land
and vineyards) and 11 % are meadows (mainly on the Danube
Island and in the Wienerwald).
Vienna is a concentric
city. The inner city is very densely built-up and lacks in
greenspace. Public parks were created in the 1950s to
provide greenspace in the residential areas surrounding the
inner city.
A green and blue
corridor was created along the Danube when the river was
regulated for flood prevention in the 1970s. This is the
most important inner-urban greenspace. Outside the city, the
large woodland area of Wienerwald was already protected at
the beginning of the 20th century. Woodlands cover over one
third of designated greenspaces. The eastern part of the
city is surrounded by intensively farmed agricultural
land.
Table 2: Categories of
green space in Vienna (MA 41, Realnutzungskartierung 1997;
Bearb.: MA 21, MA 18)
Greenstructure
change:
Agricultural land is the
main resource of space for the growth of the city. Since the
1950s, agriculture has lost more than a quarter of its area
in favour of other land uses. Since 1985, the area of
agricultural land has decreased for 15 %. In the past
decades the farmland was cleared from many of the hedges,
shrubs and trees on the field margins, so that it is a
rather monotonous landscape, which is unsatisfactory both
regarding agroecology and nature conservation and regarding
recreational use (Maurer et al., 2000).
Influence of natural and
cultural factors on the greenstructure:
Natural factors have a
great influence on the provision and composition of Vienna's
greenstructure. The city is situated at the transition of
different landscape types and climatic zones, and therefore
has a rich mix of different habitat types. The hills in the
west of city were are covered by extensive
woodlands.
Due to its history as a
major European capital, the city has a also a very important
heritage of historic parks and gardens. Vineyards are
another important cultural landscape in Vienna. No other
city in the world has larger vineyards within its
boundaries. The the vineyards and the former wine growers`
villages are popular recreation areas.
5 The greenstructure
of C.Budejovice
Provision and spatial
pattern of greenspace:
No figures or
information on greenspace provision were provided. C.
Budejovice has a historic centre which is famous for its
baroque architecture. The inner city is densely built-up. It
is surrounded by developments from the 19th and 20th
century. During industrialisation river banks and ditches
were created to protect the city from flooding but also
additional canals were built for transportation. Since the
1950s satellite towns of panel blocks of flats were
established at the outskirts, and more recently new
commercial centres were built outside the city on
farmland.
Greenstructure
change:
No information was
provided.
Influence of natural and
cultural factors on the greenstructure:
The city is situated at
the confluence of two rivers, Vltava and Malé. These
rivers formed an alluvial plain in which the city developed.
Within the city boundaries, four natural units can be
distinguished on basis of terrain features.
The streams form the
natural greenstructure of the city. Thus, several green
corridors can be distinguished along the streams connecting
parks and other greenspaces in the inner city with the
surrounding landscape.
The main railway
corridor is considered as another important greenstructure,
however, this is not recognised in the urban master
plan.
Is thera type of
greenspace table?
6 The greenstructure
of Warsaw
Provision and spatial
pattern of greenspace:
The City of Warsaw has
approximately 1 610 471 inhabitants on surface area of 494,3
km2. It gives average density of 3258 p. per km2 in 2000
(Statistical Review-Warsaw 2002).
Green open spaces cover
almost 37 percent of Warsaw's total area, according to an
inventory made in 1997 and updated in 2001 (Tab. 3.).
Municipal and state owned woodlands cover about fourteen
percent of Warsaw's surface area, public parks occupy six
percent of the city surface area and a similar size has
other greenspace.
Agricultural land covers
another 30% and surface water 4% of the city surface,
according to the land use inventory.
Tab.4. Greenspace types
of Warsaw
Warsaw's greenstructure
are the valley and terraces of river Vistula, and the Warsaw
escarpment. These form continuous green corridors through
the city from south to north. Greenspaces were also
developed along two former rings of fortifications around
the city centre.
In the 1920s, it was
proposed to develop a system of green fingers, mainly for
recreation and to maintain ventilation of the city. This
concept was implmented in subsequent city plans. However,
during the second World War, large parts of Warsaw were
completey destroyed, including the greenstructure. After
World War II, greenstructure concepts were developed but
only partly implemented. Provision of greenspace for
recreation played a major role. Quantitative standards of
per-capita provision of greenspace were adopted. From the
1970s, ecological considerations became more important. The
Urban Natural System has been promoted since then. They
stressed not only importance of preservation and
conservation of the most valuable landscape structure
elements but they recognised creation of ecological systems
through the urban areas as a key task.
Greenstructure
change:
Agricultural land is the
most vulnerable to urban development. Their rapid vanishing
has continued for last 12 years, and has been caused by fast
urbanisation process.
Influence of natural and
cultural factors on the greenstructure:
The contemporary
greenstructure of Warsaw relies on natural and historical
landscape elements. Its dependence on natural structures is
getting weaker as a result of the urbanisation processes,
but there still exist some key components, which create
visible pattern of green areas like relief, geological
basement and hydrological system.
The river Vistula and
its system of river terraces are the most important natural
influence on the city's greenstructure. Its bed is about one
kilometre wide and narrows to 350 meters in the central
district. Both banks are accompanied by riparian forest
along almost the whole way through the city. Diverse in
structure and naturalness the Vistula Valley provides wide
green open spaces in Warsaw, even in central
district.
The next significant
element of Warsaw landscape is the Warsaw Escarpment, the
edge of moraine plateau. The course of the Warsaw Escarpment
is underlined by the natural and semi natural green areas.
Its south and the north part are connected with the large
patches of open spaces, mostly forested, and thus connect
urban greenspaces with the regional
greenstructure.
The Warsaw Escarpment
was discovered as a crucial natural structure for
localization of the magnificent residential palaces, parks
and gardens or other representative objects. That is why it
has gradually become also a significant historical
landmark.
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