Urban Environmental Quality Tehran ID
Management of the Composition and Configuration of
Urban Landscape Using Urban Ecology and
Landscape Ecology Aspproaches ( A Case Study of
Tehran City – IRAN)
Yavari Ahmad-Rezaa. Parivar Parastoob . Harati Pegahc
a: Assoc. Prof., Graduate Faculty of Environment, University of Tehran-Iran
Email:ayavari@ut.ac.ir
b: Ph.D. Student of Planning and Management, Graduate Faculty of Environment, University of Tehran-Iran
c: M.Sc. Student of Environmental Economy, Azad University, Tehran-Iran
Abstract
Cities are open living systems whose land cover mosaic is greatly influenced by biophysical and socio-economic mutual driving forces. Applied sociology with spatial
explications and the representation of cultural infrastructure as well as structure and other
human factors are explicitly considered in urban ecology. According to this view, there
are social classes who control resource allocation and their property rights, and this, in
turn, greatly influences on both land use and its governance. Similar to other landscapes
the urban mosaic element's composition and their spatial configuration illustrate
processes engaged in their pattern construction and demonstrate environmental functions
that may be expected from it. By adopting a similar structure-function or pattern-process
principle, environmental planning in Tehran Metropolitan Region was undertaken.
Integration of natural and socio-economic features of the city led to nine heterogeneous
zones with different composition and configuration of green, open and built patch types;
different natural structural elements, specific community; social, capital and economic
status, and various measures (intensity and timing) of urban tissue alterations. When
these characteristics are compared to those ecological characteristics that are supposed to
reflect the environmental stability and provide environmental livability, priority planning
strategies may be defined for each zone. Based on the action plan in each zone, we
developed the refuge network plan.
Keywords: Urban Landscape, Zoning, Refuge Network, Tehran, Spatial Heterogeneity,
Driving Forces, Pattern-Process Principle
1
Introduction
The current unprecedented urbanization has confronted environmental experts with
increased negative impacts from a local to a global level (Alberti, 2005). Urban
systems are understood as open living systems in which natural and social processes
constitute its mutual and integral sub-systems. Urban systems enjoy self-awareness
and have the potential to exploit the non-genetic information in their non-biophysical
sub-systems to protect their dynamics (Pickette et al., 2004; Ahern, 2011). Today,
contrary to the conventional view about open ecological systems, they are also
externally regulated from adjacent or distant stimulating processes (Pickette et al.,
2004). This underlines the importance of natural and cultural contexts. Likewise,
various roles of human communities such as audience and planner are acknowledged
as driving forces for these open human-dominated systems whose succession is
largely determined by human governance; from near to far away and at local to global
scales. When the significance of social and natural capital is acknowledged, human
wellbeing and ecological integrity of the landscape are considered as major
assessment criteria rather than maximum economic benefit (Forster, 2002).
To recognize cities as elaborated living systems consisting of an assortment of
interrelated natural and artificial, healthy and disturbed ecosystems whose integrity at
any time is dependent on receiving the necessary feedbacks from its social subsystem
(Pickette et al., 2004). Ecological resilience of cities increases through the
accumulation of knowledge, and the ability to predict and adapt to changes without
long lag times (Anderson, 2006).
A planning strategy conducive to sustainable urban development not only considers
environmental capability or ecosystem carrying capacity (as Ian Mc Harg’s approach
to ecological landscape planning), but also takes into account spatial features of urban
environment with chorological interactions between ecosystems within landscapes
(Naveh &Lieberman 1984, Zonneveld 1995, Wiens 1995, Forman 1995 a & b,
Ingegnoli 2002,).
\
Using these principles, the environmental quality and structural features of Tehran
urban landscape was studied. The Iranian Department of Environment (DOE)
declared air- and water-related problems as the two most alarming environmental
concerns threatening public health in the capital (DOE; 2001). Ever since, longer
stagnation of emission still prevails continued costly mitigation efforts. The fact is
that the present condition of air and water resources and the prevalent environmental
ills in Tehran are largely due to a general neglect of ecological aspects in regional
land use development planning (Yavari et al., 2007). Accelerated unattended growth
of urban structures over valuable natural matrix in the suburbs has ultimately
contributed to environmental and human impoverishment and this has remained an
unattended and neglected ecological problem at the scale of landscape.
2
This study aimed to seek priority strategies for the future spatial development of
various (homogeneous) parts of Tehran based on Tehran's urban landscape structural
restoration. The composition and configuration of landscape mosaic (patches and
corridors) is addressed as a result of natural and entropic driving forces. We have used
integration of different layers of spatial data regarding natural, social and urban
environmental characteristics in order to analyze and interpret spatial and temporal
changes of landscape structure and patches composition and configuration in respect
to various environmental functions.
MATERIALs and METHODs
ehran was selected as a case study for this research study. Tehran, as the capital of Iran
with an approximate area of 700 square kilometers and a population of 8.5 million, is the
economical, cultural, and social center of Iran. Figure 1 a and 1b illustrates the map of
Tehran located in the central Alborz watershed.
The contemporary urban development pattern of Tehran dates back to only after the
Second World War, when a significant rural exodus transformed the cultural landscapes
of provincial centers; and was particularly noticeable in the capital city. As Iran’s
political, economical, cultural, and administrative capital, Tehran has undergone an
exponential growth in population. Over a 30-year period (1930-1960), Tehran’s growth
had initially been from downtown towards the north, with a vertical axis of development
that was defined by major axes of transportation at early times. Since 1970, the second
phase of Tehran’s urban growth adopted an east-to-west axis (Tehran master Plan, 2006).
Due to continued migrations, the urban growth pattern around major vertical (northsouth) axes was first replaced by a temporary east-to-west axis of growth, but supplanted
later by a sporadic, patchy growth pattern in the suburban zones. The variegated
consequences of this unattended urban growth included complex and gradual landscape
transformations veering towards an almost complete loss of natural capital accompanied
with incremental deterioration of public health conditions due to alterations of vital
ecological processes.
METHOD
Landscape ecology studies the interaction between spatial and temporal pattern and
ecological processes (Turner et al. 1998). By applying landscape ecology and urban
ecology principles, we can better understand what urban landscape alterations are and
how they may possibly be restored for an improved urban environment. The underlying
premise of urban ecology as a sub-discipline of ecology is that the explicit composition
and spatial form of an urban landscape mosaic consisting of interdependent ecosystems
affect ecological processes (Burel 2003, Forman and Godron 1986). Moreover,
chorological interdependencies between heterogeneous environments provide spatial
solutions in addressing land use objectives including urban development planning
(Forman 1995a). Urban ecology responds to the spatial dimension of urban
environmental issues or landscape function on the basis of “function-structure” feedbacks
between specific urban landscape structural alterations and particular urban
environmental functions. But all spatially relevant issues are scale dependent in the sense
that their explicit partial perception require specific scales of observation. There are no
3
normative scales of analysis because landscapes are essentially unique living entities
(Baschak & Brown 1998), and different levels of analysis at different scales are required
for a general understanding of relations between urban landscape structure and urban
environmental function or for a specific comprehension of relations between remnant
patch mosaic networks and air and water related environmental issues. In spite of the fact
that corrective measures and restoration tasks have clear priorities in respect to time and
locations within the city, an efficient restoration plan requires the adoption of an
integrated approach to cope with the complex set of corrective measures regarding the
remnant patch network and its context and to account for different scales with their feed
backs at the same or different scales separately or simultaneously.
The present study was carried out in the following stages in order to:
1. Define the driving forces affecting the urban environmental quality,
2. Mapping landscape structure,
3. Create the initial zoning by overlaying above two maps
4. Define the social driving forces
5. Overlay the initial zoning with social driving forces for the final zoning
6. Define improving measures for each zone
FINDINGS & DISCUSSION
The locations and priority for various measures leading to the promotion of urban
environmental quality could then be identified.
1. The first step was, Defining the driving forces affecting the urban
environmental quality. Table 1 presents the different aspects of the improving
measures (e.g. ecological status, grain size, and socioeconomic status) and the
list of maps provided in each aspect.
2. Locate the structures and natural driving forces by mapping. Locating the
structures and natural driving forces by mapping. It shuold be noted that for
creating maps about landscape structures, Landsat satellite data (2002) using
the FRAGSTAT software was used. Three categories of green, open, and
constructed spaces were classified and elements in each category were
evaluated in terms of their occupation area (i.e. CAP: Class Area Proportion),
the distance between elements (i.e. MNND: Mean Nearest Niebuhr Distance),
and the size of patches (i.e. MPS: Mean Patch Size). Land use maps of 1:
2,000 and 1:5,000 scales and base topographic maps of 1:25,000, officially
released by the Central Iranian Bureau of Statistic (2000 to 2004) and the
Geographical Institute of the Army (2004) were also employed.
3. Create the initial zoning by overlaying the map of structures and natural
driving forces. To do this, the map of structures was overlaid with climatic,
water resources and Geomorphologic maps. The outputs were maps
illustrating the initial zoning with 3 zones (i.e. A, B and C) and 6 sub-zones
(i.e. A1, A2, B1, B2, B3 and C)
4. Defining the social driving forces. For any urban ecological analysis, the
presence of dominant impacts of socio-economic and cultural driving forces is
evident. Without a profound understanding of social and cultural as well as
4
economic aspects it is impossible to comprehend the dynamics of urban
systems. Social driving forces were also defined in each urban area based on
the statistics made available by the National Statistical Center of Iran at the
scale of urban plots for 2007 through the followings:
Demographic: population density, and changes (migration)
Social system: organization and interdependencies of economic with
social phenomenon,
Social resources: active population, educational levels, and social
institutions,
Social organization: rights, governance and leisure,
Social changes: positions, acceptance of innovation and environmental
awareness,
Social differentiation is the result of relative presence or absence of
these attributes with their respective spatial representation.
5. Spatial integration of final zoning with social features and spatial distribution
of driving forces in Tehran to obtain the final bio-physical and socio-economic
homogeneous zones.
6. Define improving measures for each zone at the final zoning. In this stage, it
is supposed to define improving measures and the corresponding policy
orientations concerning those elements which provide the city with
environmental services by considering the characteristics of each zone. In
each zone, the general characteristics of urban landscape matrix include open
lands, farmlands, green lands and gardens. Policies and considerations for
improving the environmental conditions of each zone is presented below
5
Table1: Subsystems and driving forces affecting and being affected by urban
environmental quality.
Aspects
(subsystems)
Ecological status
(the potential of
environmental
factors in the city)
Urban status
Socioeconomic and
cultural status
Trend of changes in
open and green
spaces
Table 2:
Climate
Elevation
Cold
semiarid
14001800
Arid
Urban Landscape Using Urban Ecology and
Landscape Ecology Aspproaches ( A Case Study of
Tehran City – IRAN)
Yavari Ahmad-Rezaa. Parivar Parastoob . Harati Pegahc
a: Assoc. Prof., Graduate Faculty of Environment, University of Tehran-Iran
Email:ayavari@ut.ac.ir
b: Ph.D. Student of Planning and Management, Graduate Faculty of Environment, University of Tehran-Iran
c: M.Sc. Student of Environmental Economy, Azad University, Tehran-Iran
Abstract
Cities are open living systems whose land cover mosaic is greatly influenced by biophysical and socio-economic mutual driving forces. Applied sociology with spatial
explications and the representation of cultural infrastructure as well as structure and other
human factors are explicitly considered in urban ecology. According to this view, there
are social classes who control resource allocation and their property rights, and this, in
turn, greatly influences on both land use and its governance. Similar to other landscapes
the urban mosaic element's composition and their spatial configuration illustrate
processes engaged in their pattern construction and demonstrate environmental functions
that may be expected from it. By adopting a similar structure-function or pattern-process
principle, environmental planning in Tehran Metropolitan Region was undertaken.
Integration of natural and socio-economic features of the city led to nine heterogeneous
zones with different composition and configuration of green, open and built patch types;
different natural structural elements, specific community; social, capital and economic
status, and various measures (intensity and timing) of urban tissue alterations. When
these characteristics are compared to those ecological characteristics that are supposed to
reflect the environmental stability and provide environmental livability, priority planning
strategies may be defined for each zone. Based on the action plan in each zone, we
developed the refuge network plan.
Keywords: Urban Landscape, Zoning, Refuge Network, Tehran, Spatial Heterogeneity,
Driving Forces, Pattern-Process Principle
1
Introduction
The current unprecedented urbanization has confronted environmental experts with
increased negative impacts from a local to a global level (Alberti, 2005). Urban
systems are understood as open living systems in which natural and social processes
constitute its mutual and integral sub-systems. Urban systems enjoy self-awareness
and have the potential to exploit the non-genetic information in their non-biophysical
sub-systems to protect their dynamics (Pickette et al., 2004; Ahern, 2011). Today,
contrary to the conventional view about open ecological systems, they are also
externally regulated from adjacent or distant stimulating processes (Pickette et al.,
2004). This underlines the importance of natural and cultural contexts. Likewise,
various roles of human communities such as audience and planner are acknowledged
as driving forces for these open human-dominated systems whose succession is
largely determined by human governance; from near to far away and at local to global
scales. When the significance of social and natural capital is acknowledged, human
wellbeing and ecological integrity of the landscape are considered as major
assessment criteria rather than maximum economic benefit (Forster, 2002).
To recognize cities as elaborated living systems consisting of an assortment of
interrelated natural and artificial, healthy and disturbed ecosystems whose integrity at
any time is dependent on receiving the necessary feedbacks from its social subsystem
(Pickette et al., 2004). Ecological resilience of cities increases through the
accumulation of knowledge, and the ability to predict and adapt to changes without
long lag times (Anderson, 2006).
A planning strategy conducive to sustainable urban development not only considers
environmental capability or ecosystem carrying capacity (as Ian Mc Harg’s approach
to ecological landscape planning), but also takes into account spatial features of urban
environment with chorological interactions between ecosystems within landscapes
(Naveh &Lieberman 1984, Zonneveld 1995, Wiens 1995, Forman 1995 a & b,
Ingegnoli 2002,).
\
Using these principles, the environmental quality and structural features of Tehran
urban landscape was studied. The Iranian Department of Environment (DOE)
declared air- and water-related problems as the two most alarming environmental
concerns threatening public health in the capital (DOE; 2001). Ever since, longer
stagnation of emission still prevails continued costly mitigation efforts. The fact is
that the present condition of air and water resources and the prevalent environmental
ills in Tehran are largely due to a general neglect of ecological aspects in regional
land use development planning (Yavari et al., 2007). Accelerated unattended growth
of urban structures over valuable natural matrix in the suburbs has ultimately
contributed to environmental and human impoverishment and this has remained an
unattended and neglected ecological problem at the scale of landscape.
2
This study aimed to seek priority strategies for the future spatial development of
various (homogeneous) parts of Tehran based on Tehran's urban landscape structural
restoration. The composition and configuration of landscape mosaic (patches and
corridors) is addressed as a result of natural and entropic driving forces. We have used
integration of different layers of spatial data regarding natural, social and urban
environmental characteristics in order to analyze and interpret spatial and temporal
changes of landscape structure and patches composition and configuration in respect
to various environmental functions.
MATERIALs and METHODs
ehran was selected as a case study for this research study. Tehran, as the capital of Iran
with an approximate area of 700 square kilometers and a population of 8.5 million, is the
economical, cultural, and social center of Iran. Figure 1 a and 1b illustrates the map of
Tehran located in the central Alborz watershed.
The contemporary urban development pattern of Tehran dates back to only after the
Second World War, when a significant rural exodus transformed the cultural landscapes
of provincial centers; and was particularly noticeable in the capital city. As Iran’s
political, economical, cultural, and administrative capital, Tehran has undergone an
exponential growth in population. Over a 30-year period (1930-1960), Tehran’s growth
had initially been from downtown towards the north, with a vertical axis of development
that was defined by major axes of transportation at early times. Since 1970, the second
phase of Tehran’s urban growth adopted an east-to-west axis (Tehran master Plan, 2006).
Due to continued migrations, the urban growth pattern around major vertical (northsouth) axes was first replaced by a temporary east-to-west axis of growth, but supplanted
later by a sporadic, patchy growth pattern in the suburban zones. The variegated
consequences of this unattended urban growth included complex and gradual landscape
transformations veering towards an almost complete loss of natural capital accompanied
with incremental deterioration of public health conditions due to alterations of vital
ecological processes.
METHOD
Landscape ecology studies the interaction between spatial and temporal pattern and
ecological processes (Turner et al. 1998). By applying landscape ecology and urban
ecology principles, we can better understand what urban landscape alterations are and
how they may possibly be restored for an improved urban environment. The underlying
premise of urban ecology as a sub-discipline of ecology is that the explicit composition
and spatial form of an urban landscape mosaic consisting of interdependent ecosystems
affect ecological processes (Burel 2003, Forman and Godron 1986). Moreover,
chorological interdependencies between heterogeneous environments provide spatial
solutions in addressing land use objectives including urban development planning
(Forman 1995a). Urban ecology responds to the spatial dimension of urban
environmental issues or landscape function on the basis of “function-structure” feedbacks
between specific urban landscape structural alterations and particular urban
environmental functions. But all spatially relevant issues are scale dependent in the sense
that their explicit partial perception require specific scales of observation. There are no
3
normative scales of analysis because landscapes are essentially unique living entities
(Baschak & Brown 1998), and different levels of analysis at different scales are required
for a general understanding of relations between urban landscape structure and urban
environmental function or for a specific comprehension of relations between remnant
patch mosaic networks and air and water related environmental issues. In spite of the fact
that corrective measures and restoration tasks have clear priorities in respect to time and
locations within the city, an efficient restoration plan requires the adoption of an
integrated approach to cope with the complex set of corrective measures regarding the
remnant patch network and its context and to account for different scales with their feed
backs at the same or different scales separately or simultaneously.
The present study was carried out in the following stages in order to:
1. Define the driving forces affecting the urban environmental quality,
2. Mapping landscape structure,
3. Create the initial zoning by overlaying above two maps
4. Define the social driving forces
5. Overlay the initial zoning with social driving forces for the final zoning
6. Define improving measures for each zone
FINDINGS & DISCUSSION
The locations and priority for various measures leading to the promotion of urban
environmental quality could then be identified.
1. The first step was, Defining the driving forces affecting the urban
environmental quality. Table 1 presents the different aspects of the improving
measures (e.g. ecological status, grain size, and socioeconomic status) and the
list of maps provided in each aspect.
2. Locate the structures and natural driving forces by mapping. Locating the
structures and natural driving forces by mapping. It shuold be noted that for
creating maps about landscape structures, Landsat satellite data (2002) using
the FRAGSTAT software was used. Three categories of green, open, and
constructed spaces were classified and elements in each category were
evaluated in terms of their occupation area (i.e. CAP: Class Area Proportion),
the distance between elements (i.e. MNND: Mean Nearest Niebuhr Distance),
and the size of patches (i.e. MPS: Mean Patch Size). Land use maps of 1:
2,000 and 1:5,000 scales and base topographic maps of 1:25,000, officially
released by the Central Iranian Bureau of Statistic (2000 to 2004) and the
Geographical Institute of the Army (2004) were also employed.
3. Create the initial zoning by overlaying the map of structures and natural
driving forces. To do this, the map of structures was overlaid with climatic,
water resources and Geomorphologic maps. The outputs were maps
illustrating the initial zoning with 3 zones (i.e. A, B and C) and 6 sub-zones
(i.e. A1, A2, B1, B2, B3 and C)
4. Defining the social driving forces. For any urban ecological analysis, the
presence of dominant impacts of socio-economic and cultural driving forces is
evident. Without a profound understanding of social and cultural as well as
4
economic aspects it is impossible to comprehend the dynamics of urban
systems. Social driving forces were also defined in each urban area based on
the statistics made available by the National Statistical Center of Iran at the
scale of urban plots for 2007 through the followings:
Demographic: population density, and changes (migration)
Social system: organization and interdependencies of economic with
social phenomenon,
Social resources: active population, educational levels, and social
institutions,
Social organization: rights, governance and leisure,
Social changes: positions, acceptance of innovation and environmental
awareness,
Social differentiation is the result of relative presence or absence of
these attributes with their respective spatial representation.
5. Spatial integration of final zoning with social features and spatial distribution
of driving forces in Tehran to obtain the final bio-physical and socio-economic
homogeneous zones.
6. Define improving measures for each zone at the final zoning. In this stage, it
is supposed to define improving measures and the corresponding policy
orientations concerning those elements which provide the city with
environmental services by considering the characteristics of each zone. In
each zone, the general characteristics of urban landscape matrix include open
lands, farmlands, green lands and gardens. Policies and considerations for
improving the environmental conditions of each zone is presented below
5
Table1: Subsystems and driving forces affecting and being affected by urban
environmental quality.
Aspects
(subsystems)
Ecological status
(the potential of
environmental
factors in the city)
Urban status
Socioeconomic and
cultural status
Trend of changes in
open and green
spaces
Table 2:
Climate
Elevation
Cold
semiarid
14001800
Arid