evaluation of plant groups and vegetation types for use on green roofs

8/10/2019 Evaluation of Plant Groups and Vegetation Types for Use on Green Roofs

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Evaluation of plant groups and vegetation types for use on green roofs

This work contributes to an established program which uses a standard methodology to screen and

evaluate plants and vegetation types for green roof use (of all types), according to substrate depth,

substrate type, irrigation regime etc. Specific genera, vegetation types and habitats, or geographic

regions can form the basis of studies in this area. This is an on-going program that can accommodate a

number of separate studies.

Green roofs and biodiversity

Green roofs represent an opportunity to create habitat and promote biodiversity (both floral and faunal) in

dense urban development. Many different approaches have been promoted as to how this is best

achieved (though, for example, use of recycled, reclaimed substrates, spontaneous colonization of

vegetation, use of native species or local provenance plant material). This study will test such assertions,

concentrating on both floral and invertebrate diversity.

LANDSCAPE-LAND USE PLANNING NEWSLETTER, SUMMER 2008

Landscape Planning and Land Use Planning: Definitions, History and Roles

by Mark ORourke, ASLA

Land use illustration for the City of San Luis Obispo, California. The planningestablishedthe first form based zoning ordinance in the Central Coast.Image courtesy of Rick Engineering Company.

In assessing the data from the PPN survey, the Co-chairs recognized a need to explore,discuss, and clarify landscape planning, land use planning, and their relationship.This piece defines these specialties, and describes how they developed, how they aresimilar and differ, and how they have evolved.

Common Roots of Landscape Planning and Land Use Planning

Landscape planning and land use planning are two separate though complementaryfields. The roots of landscape architecture are embedded in both landscape planningand land use planning. Frederick Law Olmsted was a landscape planner (the EmeraldNecklace) and a land use planner (Riverside, IL). Today, many landscape architectspractice both landscape planning and land use planning.
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Definition, History and Focus of Landscape Planning

Landscape planning can be defined as the scientific study of landscapes to assess past,current, and future capabilities to support different land uses that also accounts forenvironmental and ecological health. It has evolved into a scientific discipline practiced

by landscape architects, planners, and natural resource scientists. In practice,landscape architects who use McHargian overlay analysis and assessment as part oftheir design process are doing landscape planning.

Landscape planning can be traced to ancient architects and builders. Marcus VitruviusPollio (born c. 8070 BC, died after c. 15 BC) wrote about the importance ofmicroclimates, vegetation, and hydrology in the planning of new settlements and cities.The modern practice of landscape planning can be traced from Olmsted with his holisticapproach to planning park systems. Patrick Geddes (18541932), the first bio- andsocio-regional planner, and Warren Manning (18601938), a pioneer of early overlayanalysis, were great influences in the modern development of landscape planning.

In the 1960s, an evolution in landscape planning occurred in concert with a new andvital environmental awareness. Ian McHarg (19202001) reintroduced the concept ofoverlay analysis with an emphasis on ecology and conservation of natural resources.The evolution of overlay analysis by McHarg was instrumental in the design anddevelopment of geographic information systems (GIS) as an invaluable analysis andassessment tool in all fields of planning. The field of landscape planning has evolvedinto a first step in the regional or land use planning process. In the United States, it ismore frequently practiced by natural resource scientists in the fields of hydrology,forestry, geology, and watershed management. However, academically, landscapearchitects are very involved in the multidisciplinary process of the analysis and

assessment of landscapes.Definition, History and Focus of Land Use Planning

Land use planning is analogous to regional planning, community planning, urban planning, and any otherplanning exercise that ultimately plays a role in defining how land is used.

Within the professional planning community, the term land use planning is not commonly used. This is theresult of the evolution of planning from strictly planning land use to a more equal concern with economicdevelopment, environmental justice, and social and economic equity. In the last two decades, theplanning profession has again been more focused on land use planning, but has changed the terminologyto Smart Growth, Sustainable Planning, Regionalism, etc. The tools for land use planning are zoninglaws, subdivision and land use laws, and stormwater laws and regulations. Land use planners have also

been involved in the transfer of development rights, purchase of development rights, farmland andforestry preservation programs, and additional programs to help guide land development. They alsodetermine appropriate land uses based on ecological carrying capacity, historic land use, future regionaldevelopment pressure, and economic development needs.

Current and Future Uses of Landscape Planning and Land Use Planning

Landscape planning and land use planning are synergistic in that landscape planning informs the policy-making and legal structure of comprehensive land use planning. Some examples where this occurs are


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In order to distribute the open space in the city, Christaller's model ofurban hierarchical order was adapted and refined. Christaller(1) postulatedthat the more important a city's economic function, the larger the city'spopulation. He added that cities were spaced to perform functions withoutsevere competition from the others. This is referred to as 'distanceinterval'.

A similar approach was applied to the Open Space Framework. If the openspace was likened with a city then active and passive leisure facilitiescould be depicted as its economic functions. The open space would be

larger the greater it's provision of park facilities. The greater the numberof facilities provided the larger the attraction and vice versa. Thereforesmaller open spaces (City Parks), with fewer facilities, would serve asmaller proportion of the population without competing with the largeropen spaces (Metropolitan Parks). The diagram illustrates the applicationof Christaller's model to the distribution and size of open space in a newlyplanned city (Diagram 1).

The theory was applied to open space thus:Distribution. Open spaces were spaced at even distances according to size

of open space and size or catchment of population that it served .Facilities. The size of the open space roughly related to the breadth anddepth of sport, leisure and rest facilities provided in the open space.

Interconnections

A further layer of the 'Green Continuum' was the provision of interconnections between the openspaces. Visual interconnections aim to provide a clearer image of the city and, if visually stimulating,encourage movement from one space to another. Physical connections between the open spaces allowpedestrian and cycle movement within the city and out to the areas beyond the city. This pedestrianand cycle movement system utilising Green Corridors was intended to be dominant over the footpathat the sides of roads. Such legibility and permeability ensure the full integration of the builtenvironment of the city with the natural environment further reinforcing the Open Space Framework

spatial structure.

Retention of Existing Landscape Features

Unique physical identity was also to be achieved through respecting the natural setting with theexisting and proposed distinctive physical forms including:

the retention of the existing rolling hills terrain,

retention of native vegetation and strategic plantation vegetation to create maturity,

utilisation of water catchment with the retention of existing streams and water catchmentsand the creation, by damming, of artificial lakes, and

employment of the prominent vistas in order to take advantage of the rich visual quality.

Respect for site context therefore contributed to attaining Malaysian identity.
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Greening the City

The effective use of large trees and palms whose canopies and crowns, over time,join together to provide a strong 'green' visual impact aimed to further reinforcethe 'Green Continuum'.

Trees provide shade, colour and fresh air and can provide a lasting visualimpression in the memory of residents and visitors of the city. Therefore the visualbenefits of a 'continuous green' not only include calming, on both the eye andsenses, but also a means of providing visual delight. In addition there are themicroclimatic benefits of tree cover in the form of cooling the air by providingshade, reducing noise and improving air quality due to the effects of leaves. The'Green Continuum' in terms of the relationship between built form and open space,

as well as the means of 'greening' the open areas of the city, were to be achievedin a variety of ways as illustrated in the diagram (Diagram 2).

This concept was determined to be achievable for many disciplines such as

planning, in terms of land use; architecture in terms of specific site planning;transport with non-vehicular movement; and landscape with the creation of three-dimensional volumes, a viable active public realm and an extensive tree plantingprogramme.

Urban Forest

Malaysia is covered with some of the oldest rainforest in the world and it is the true natural heritage ofMalaysia being the original home of its people. Looking to the future a young tree in the present shalleventually become the heritage for future generations. The forest can therefore be a metaphor forboth past and future as well as providing a strong sense of Malaysian identity. The application of theUrban Forest to Putrajaya, in the form of a Green Continuum, draws on the diversity and essence ofthe rainforest and weaves it into the fabric of the orderly and functional city.

In fulfilling the objectives to provide a network of interlinked open spaces and to provide a substantialvegetative cover the concept of the Urban Forest provides another layer in the design of the city. Theconcept of Urban Forest is expressed in an urban setting as an extensive tree cover utilisingpredominantly native trees. Public open spaces are the obvious setting for large scale tree planting.However private grounds and gardens can also contribute. Also of primary importance are street treeswhich can be planned in advance to accommodate large quantities of trees.

The role of the Landscape Architect, when involved in designing both a new city or revitalising anexisting city, is very much in the realms of urban design. As learnt from the Putrajaya experience theworld's cities tangibly benefit from Landscape Architect led masterplans and urban design.

The currently reported shortage of Urban Designers and the lack of emphasis on training in urban

design demands that Landscape Architects seize the opportunities for further broadening their scope.After all, what are Landscape Architects if they are not designers of spatial masterplans and strategistsfor open space and the public realm?
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Tehran, the City of River Valleys, Needs a

Landscape Ecological Approach to the

Design and Planning of Its WaterwaysPosted onJuly 16, 2014byKaveh Samiei

About the Writer:Kaveh Samiei

Kaveh Samiei is founder, principal architect and landscape designer at AAG in Tehran, and faculty member inschool of architecture and urban planning at the University of Semnan. He works and researches on the frontier

between architecture and landscape architecture.

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Agoal of landscape ecological urbanism might be to design and plan cities to increase, rather than

to decrease, ecosystem services. This suggests exciting new areas of research in landscape andurban planning, from ways to measure landscape.Frederick Steiner,Landscape ecological urbanism: Origins and trajectories. (Steiner, 2011)Cities should be an extension of our natural environment. But nature has rules by which it operates,and these must be built into urban designs that mesh the organic and inorganic parts of the city(Samiei, 2013).

During recent years, the municipality of Tehran began to work on rehabilitation of river valleys.Three projects now are completed or near completion. This great movement can improve anddevelop the quality and quantity of Tehran environment, which is in a dangerous and catastrophic

conditionbut only if planners, designers and other decision makers pay attention to all aspects ofrehabilitation, especially ecological and environmental principles like connectivity, coherenthydrology, compatible plantation, controlled interfering, considering buffer zones and so on. Theriver valleys often are a neglected part of Tehrans urban landscape and most of them have tragic

stories and inelegant features. Planning for their conservation and restoration should start for theremaining and unprotected rivers quickly because Tehran is the city of river valleys!
http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/http://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/author/kavehsamiei/mailto:[email protected]:[email protected]://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/author/kavehsamiei/http://addthis.com/bookmark.php?v=300http://addthis.com/bookmark.php?v=300http://www.thenatureofcities.com/author/kavehsamiei/mailto:[email protected]://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/


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Tehran takes advantage of having this potential,but the approach and the circumstances and specificplans for carrying out rehabilitation projects are critical. Bringing the dream of a significant urbanproject into being needs the consideration all aspects of multipurpose and multilayered planning.

River valleys as ecological elements have always had key roles in creating mutual relations betweenman-made city spaces and nature. River valleys play important roles in the provision of fresh waterresources, natural green and blue corridors for climate moderation, green open spaces, biodiversity,parks, recreational areas, as well as places for public services. Investigations of the current conditionof Tehrans River valleys indicate that not only do they not increase the quality of environment, in

fact they play a negative role (Bemanian, 2008).

Tehran, the capital and largest city in Iran, has experienced rapid growth, especially in the past threedecades. Tehran has more than 12 million inhabitants and despite all the efforts by responsibleorganizations to improve environmental conditions, it is contaminated with various environmental

pollutants and its ecological structure has experienced numerous degradations. Recent developmentof parks and public green space has not been able to restore an ecological network fragmented byunplanned and uncontrolled growth (Bahrami et al., 2012).

The ecological landscape of Tehran

Greater Tehran consists of three sections: mountainous, piedmont and desert. The mountainoussection includes peaks over 1800 meters. In this section, due to the height and legal restrictions, thereare no residences or construction. Thus Tehran has physically developed in the other twosections. The southern parts of the city have grown along a wide, flat desert. The city, however,cannot expand along the plain due to the high levels of Ground water and the arid zone. So the city

can only expand in the western direction due to its suitable geographical condition and newresidential estates have mostly developed in this direction. The topographical conditions of the citydirectly influence the spatial texture of the city, especially in the northern side (Tehran Atlas, 2014).

From the south toward the north, the altitude increases, from 900 meters in low areas to 1800 meters.This difference in height results in differences in weather, better vegetation and beautiful countrysidein the north. As one moves from the south to the north, where are many changes in the naturalenvironmental conditions, property value, access to services and social conditions.


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Geomorphology of Tehran. Source:atlas.tehran.irThe Alborz mountain chain in the north of the City, the river valleys of the Darabad, Golab Dare,Farahzad, Kan, Evin and the low hills and urban forest parks (e.g., Lavizan, Sorkhe hesar, chitgar,Quchak) are examples of primary landscape elements which are intrinsically linked with Tehranecological network, and provide an essential sense of place which can be appreciated from manyvantage points within the city. There are other more local landscape elements that can help give areasa sense of place and which can be referred to as secondary landscape elements (Bahrami and K.V.).Among other landscape features are natural and manmade patches, which give Tehran its uniquecharacteristics and residential and touristic values. One of its most important natural patchesare northern heights which endow the city with a special natural characteristic.

Today, Tehran has lost many of its natural patches due to rapid growth. Urban constructions havealso caused the gradual destruction of natural patches, which were situated along geologicalcorridors, near local water resources. The development of manmade natural patches has also shownthat even though the number of parks and green patches has been increased, these newly naturalpatches have not been made sustainable. They have shown little efficiency due to their small size andlack of ecological integration. These patches have been made without paying attention to landscapecapabilities and water and soil resources. As a result, most of the newly-established green patcheshave been built on uncultivated hills and lands without suitable water and soil resources. In Tehran,there has always been a shortage of water, and because of this, water has often been taken from other

areas, thus causing the eventual destruction of more natural landscapes. Unfortunately, the newly-established green patches have not been able to perform as ecological substitutions (Barghjelveh andSayad, 2011).

The natural-built matrix of Tehrans landscape varies from the natural mountains to the urbancontext. There are patches of nature in the center and an agricultural landscape and the desert edge inthe south. The protected lands and forests in the east change to the very densely built areas in the
http://atlas.tehran.ir/Default.aspx?tabid=239http://atlas.tehran.ir/Default.aspx?tabid=239http://atlas.tehran.ir/Default.aspx?tabid=239http://atlas.tehran.ir/Default.aspx?tabid=239


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center and also to open and built green areas in the west. Tehrans metropolitan matrix is

defragmented by natural and built corridors, which provide the basis for a heterogeneouscombination of natural and built patches that form the urban landscape structure and define itsfunctions and transformations (Aminzadeh and Khansefid, 2009).

Therefore, with the increase of urban constructions and the continuous destruction of landscapes

natural resources, there are no more valuable areas in Tehran that can be considered as naturalpatches. Except for large patches dispersed in the northern foothills and the margins of the city,which are ecologically disconnected, natural patches within the landscape are small ones. It is worthnoting that patches near the natural corridors are ecologically historic as well as valuable in terms ofextent. These areas are not only considered as landscapes micro-scale ecological patches, but due totheir expanse and the presence of hydro-corridors, they are also able to act at the landscapes macro-scale ecological activities. These patches are also important in terms of having access to citys

recreational potentials as well as different urban land uses and functions. These characteristics andcapabilities add to the ecological importance of these patches.

Thus, the river valley corridors and remnant natural patches in the middle and built green patches inthe east and west of the Tehran are considered as main structural elements in Tehran urban ecologicalsystem (Bahrami and K.V.).


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River valleys as natural corridors

Tochal peak is 3900 meters in altitude. Its main ridges overlook the southern slopes and Tehranplain, and forms small drainage basins. The rivers flowing in these basins are the life veins of thecity. Water constantly flows in these basins and probably the main reason why Tehran developed isits hydromorphological conditions influenced by its northern heights. The most important basin,

which covers the southern slopes of the northern heights of the city, include: Kan, Farahzad, Darakehand Darband basins.

The seven northsouth river valleys are characteristic of natural corridors of Tehrans landscapestructure. They are fertile habitats that support a variety of flora and fauna and play significant rolesas catchments and as places for energy and wind flows to remove air pollutions from the cityenvironment, providing opportunity for connection with the natural uplandlowland context. Uplandareas benefit from much better conditions than lowlands due to less environmental destruction causedby urban development. The natural hydrological corridors along the river valleys face moredestructive factors and have less ecological functions from north to south because of their structural

modifications. Natural corridors connect many natural and built patches scattered along them. Thesecorridors are mostly oriented in a northsouth direction. The eastwest ecological connections arerestricted due to the morphological structure of city (Aminzadeh and Khansefid, 2009).

The rivers and streams that run through these mountain valleys and inside the city are among theadvantages of Tehrans landscape, and their ecological potential creates desirable urban patches

within the manmade urban fabric. In addition to the provision of open spaces, concentration of mainviews and circulation of pure air, these natural corridors are among the major elements of Tehrans

comprehensive plan to revive its landscape. In order to create continuous and expansive naturalpatches and assure spatial interconnection between natural greens and manmade spaces, thesecorridors are considered the main natural elements of Tehrans sustainability development plan.

Tehrans natural corridors, which run in main routes, do not have ecological buffers and as a resulttheir ecological functions as connecting routes are limited. Even, constructed urban corridors(including riverside corridors and greenways) have urban functions due to being connected to urbanzones. Thus, these corridors have special characteristics in terms of having important ecological andsocietal advantages in different landscape scales. The recreational potentials of these landscapes arealso considerable. They are remarkable areas not only because they are rich ecological resourcesproviding large green patches, but also because they are important cultural sites that provide thelandscapes historic identity. Sometimes these areas along with their manmade urban elements

benefit from the landscapes naturalcharacteristics and become considered historic urban elementsthat define cultural functions. However, other times they remain poor in terms of plantation, andthough they have the spatial capability to benefit from landscapes natural patches and corridors,nonetheless, they remain in need of good ecological connectivity. The vicinity of historic urbanstructures with valuable natural sites helps to protect the socio-ecological identity of the landscape.All these factors allow the manmade identity of the landscape to be in harmony with its natural andhistoric characteristics (Barghjelveh and Sayad, 2011).


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By looking carefully at Tehrans ecological map and considering rehabilitation of Kan and Farahzad

river valleys, it seems there has been no attempt at making connectivity to other patches or corridors!Also the density in some parts, particularly along two river valleys misses the chance for extendingthem into urban fabric in future. The other problem is many existing bridges of eastwest highways,which usually cut the river valleys corridors and decline the ecological function.

Landscape planning should minimize isolation of natural landscape remnants and maximize linkagesto provide for flows of energy, mineral nutrients, and species. An example of this would be tominimize barriers between the river valley and adjacent vegetation patches. (Baschak and Brown,1995) It is apparent, as humans engage in landscape planning and design to restore previously alteredecosystems or protect existing fragments of natural systems, that the most effective way to restore orretain ecological integrity is to ensure that these elements are connected as part of a larger system.(Cook, 2000)

In local scale, the first comparisons between two images (after and before) rehabilitation show theobvious differences in land and river form related to direct interfering in natural features of river. Inother hand, the urban river has been transformed to a big urban gutter! Even the inner sides and thebed of rivers are covered by concrete that have extremely impressed the hydrological function ofriver.

Rivers provide their regions with some natural benefits of critical importance and therefore that mustbe protected. Natural characteristics of river like meanders, backwaters, wetlands, and graduallysloped banks have important ecological functions. There are also benefits for inhabitant such ascleaner water and flood storage. It might not be possible to restore these features in many urban

areas, but even a little effort can bring about a positive effect. Environmental improvements can beachieved on even the most heavily impacted rivers.


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Farahzad river valley before (2004)(LEFT) and after (2014)(RIGHT) rehabilitation. Source: Google Earth

Kan river valley before (2008)(LEFT) and after (2014)(RIGHT) rehabilitation. Source: Google Earth.


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Farahzad river valley after rehabilitation. Source: www.negahmedia.ir

Kan river valley after rehabilitation. The urban river has been transformed to a big urban gutter! Source: hamshahrionline.ir


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Farahzad river valley under construction; imposing too many changes by interfering in land and river form will impress the

ecological function of river valley! Source: www.eshiraz.ir

Protection of natural river features and functions necessitates avoiding the use of new dams and otherengineering solutions, such as a straightening, channelizing, or placing streams in underground pipes

and culverts. It might be possible to fully restore the ecological features and functions in most urbanrivers and streams (Cengiz, 2013).

Imposing excessive hardscapes on natural and morphological forms of the site has eclipsed theecological role of river valley in urban fabric. Although each construction project will impose itselfon natural environment, it seems that the designers wanted to recreate the space and rivers site in

order to achieve other goals. Beyond the limit interfering in natural form of land and river anddesigning recreational park with maximum use of hardscapes without attention to ecologicalproperties of site, prove that the rehabilitation have replaced by recreation! However both of theprojects have different characteristics like site topography, river shape and so on, the designers

havent any other target except making a recreational space by the recreation of space!

In fact the ecological potentials of rehabilitating two of the limited natural elements of Tehranslandscape ecology has been failed and ignored completely!

Hardscapes are such places as roads, parking lots, sidewalks, driveways, paved paths, rooftops, andother impermeable surfaces that prevent rainwater from filtering through soil and replenishing riversand stream as groundwater. Nearly half of all stream flows are provided by groundwater. Thispercentage can increase to a much higher level during drought periods (Alley et al., 1999). The urbanrivers are also adversely affected by these impermeable surfaces of hardscapes as they do not absorb

stormwater. In fact, they result in considerable increases in the volume and velocity of rainwaterrunoff. Another adverse effect of paved surfaces is their contribution to pollution as they washessurface oils, fertilizers, heavy metals, bacteria, and other contaminants into river and streams.Through the reduction of hardscapes and installation of natural landscapes, it can be possible torestore natural watershed functions, filter pollutant, and prevent erosion of banks and channelizationof streambeds. The replacement of hardscape with soft, permeable surfaces, such as native grasses,shrubs, and trees in older, industrial or abandoned riverfront areas will improve environment fromboth aesthetic and ecological aspects. Planners must minimize the amount of hardscapes if theycannot be avoided. The reduction of hardscapes in new development projects can offer costefficiency for local governments, developers, and homeowners. It is expensive to install and maintain

infrastructureroads, sidewalks, sewer liner, curbs and gutters, and parking spaces (Cengiz, 2013).

Another problem is the lack of attention to native and adaptable plantation. At first view during visitsto both sites, the paucity of varieties and using ornamental and nonnative plants widely prove thatclaim! However, as old images show, the vegetation of two sites has been extremely poor. The poorand incompatible vegetation cant support and protect biodiversity and wildlife habitats across theriver valley and so it will lose its role of it as natural corridor. Unfortunately, most of the potential


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for creating rich green spaces has been missed due to paving for cycling, hiking, camping or parkinglots.

Considering buffer zones for river valleys is another important principle that apparently has beenneglected by designers and planners of the two projects. Buffer zones are areas situated next to ashoreline, wetland, or stream where development is restricted or prohibited. They facilitate theprotection of ecological integrity of rivers, enhance connections between wildlife habitats, and allowrivers to function more naturally. A buffer network serves as right-of-way for a river or stream andit is an indispensable part of the stream ecosystem. Various sizes of buffers help protecting thenatural areas close to rivers and streams, and especially fragile zone like steep slopes and wetlands. Awell designed buffer zone helps protecting the quality of water and habitats for plant and wildlife.Buffers also provide shadow areas which decrease the temperature of water and thus protect aquatichabitat. With trees, shrubs, grasses and other native plants, they provide cover and food for birds,mammals, and other animals along the river. There are also benefits for humans as flourishingbuffers are visually appealing and can often be used as greenbelts, parks and recreation areas. There

is no advantage for biodiversity in keeping manicured lawns, formal landscape designs, and prunedshrubs as they frequently require the use harmful pesticides, and do not provide the food or shelterfor wildlife (Cengiz, 2013).

Although the recreation feature of these rehabilitation have resulted in satisfied users, their lack tohigh quality ecological function will present major challenges in the future.

Other scientific researches (Barghjelveh and Sayad, 2011) also show that inthe process ofregenerating the natural environment of Tehansriver valleys, including Farahzad River-valley, the

principles of landscape ecology have been disregarded. In effect, no attention has been paid to thenatural and ecologic potentials of these landscapes. In the case of Nahjolbalagheh Garden

[Farahzad river valley], the project has been completed as if its only purpose has been to establish a

beautiful garden. Disregards for the microclimate, the plant and animal diversity, the non-local plant

cultivation incompatible with the context, unfavorable and nonsustainable cycle of matter and

energy, infiltration of pollutants into the ecosystem (especially the ecosystem of river-valleys), and

finally the absence of ecological connectivity to other urban landscapes are issues that may cause

serious local problems and even the ecological destruction of Tehranslandscape in the not so

distantfuture.


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Existing bridges of eastwest highways which usually cut the river valleys corridors and decline the ecological function. Source:

Google Earth.

Left: The dominance of ornamental and recreational elements along with poor vegetation. Right: Construction within the

boundary of river valley threats the buffer zone and river scenery! Source: tafrih.ir

Conclusion

Unfortunately, the study and evaluation of Kan and Farahzad river valleys rehabilitation projectsdemonstrates the necessity of changing minds and approaches when doing the similar projects in thefuture. The necessity comes from missing landscape ecological approach to design and planning inorder to utilizing important potentials of Tehrans river valleys as natural corridors and connectors.

River valleys are significant and inseparable parts of Tehrans landscape ecology and require moreattention during the process of decision making by municipalities, planners and designers.

Based on the potentials and the restrictions of the landscape, the solutions for enhancing theecological connectivity of urban natural public spaces are provided through the hierarchy oflandscapes Environmental Equilibrium, Geographical-anthropological Sustainability and Eco-environmental-societal Excellence features. By monitoring Tehrans river-valleys content


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composition and spatial configuration variables, the functional quality of Tehrans natural resources

is restored (Barghjelveh and Sayad, 2011).

The main focus is the application of the concept of eco-hydrology through the rehabilitation of theTehrans river-valleys as an ecological network linking the landscapes highly attractive ecological,recreational and residential areas. The key element is the ecological management of the Tehransriver-valleys as the spatial link between geomorphology, vegetation, hydrology and land use, and asthe integrated network between major natural corridors and patches within and outside the city,connecting natural and manmade green patches in order to improve the ecological networks citywide.

Kaveh Samiei

TehranOnThe Nature of CitiesReferences

1- Steiner, Frederick (2011): Landscape ecological urbanism: Origins and trajectories, Landscapeand Urban Planning, Elsevier 100 (2011) 333337.

2- Samiei, Kaveh (2013): Architectureand Urban Ecosystems: From Segregation to Integration,TNOC.http://www.thenatureofcities.com/2013/05/26/architecture-and-urban-ecosystems-from-segregation-to-integration/3- Bemanian, Mohammad Reza (2008): The Environmental Planning Revitalization for RiverValleys of Tehran in Strategic Factors Analysis Approach (SWOT) (Case study: Velenjak RiverValley), ENVIRONMENTAL SCIENCES Vol.5, No.4, summer 2008.

4- Bahrami, B; Salehi, E; Jafari, H; Irani Behbahani, H (2012); Urban Ecological LandscapePlanning and Design From the Garden City toward Modern City- A Case Study: Tehran City inIran; International Journal onTechnical and Physical Problems of Engineering, Issue 11 Volume 4

Number 2 Pages 128-134.

5- Baschak, Lawrence A. and Brown, Robert D. (1995): An ecological framework for the planning,design and management of urban river greenways, LANDSCAPE AND URBAN PLANNING,VOLUME 33, ISSUE 2, 1995, PAGES 211-225.

6- Cook, Edward (2000): Ecological Networks in Urban Landscapes, PhD Thesis, Wageningenuniversity, The Netherlands.

7- Tehran atlas (2014): Atlas of Tehran Metropolis; Municipality of Tehran:http://atlas.tehran.ir/Default.aspx?tabid=1668- Barghjelveh, Shahindokht and Sayad, Nima (2011): Using the Component Model of SustainableLandscape for the Quality Assessment of Urban Natural Public Spaces: A Case Study from Tehrans
http://www.thenatureofcities.com/http://www.thenatureofcities.com/http://www.thenatureofcities.com/http://www.thenatureofcities.com/2013/05/26/architecture-and-urban-ecosystems-from-segregation-to-integration/http://www.thenatureofcities.com/2013/05/26/architecture-and-urban-ecosystems-from-segregation-to-integration/http://www.thenatureofcities.com/2013/05/26/architecture-and-urban-ecosystems-from-segregation-to-integration/http://www.thenatureofcities.com/2013/05/26/architecture-and-urban-ecosystems-from-segregation-to-integration/http://atlas.tehran.ir/Default.aspx?tabid=166http://atlas.tehran.ir/Default.aspx?tabid=166http://atlas.tehran.ir/Default.aspx?tabid=166http://www.thenatureofcities.com/2013/05/26/architecture-and-urban-ecosystems-from-segregation-to-integration/http://www.thenatureofcities.com/2013/05/26/architecture-and-urban-ecosystems-from-segregation-to-integration/http://www.thenatureofcities.com/


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River-valleys, International Journal Of Architecture and Urban Development Vol.1, No.2, Autumn2011.

9- Bahrami, Behrang and Aiyanna K.V. (?): Urban Ecological landscape of Tehran, University ofMysore, India.

10- Aminzadeh, Behnaz and Khansefid, Mahdi (2009): A case study ofurban ecological networksand a sustainable city: Tehrans metropolitan area, Urban Ecosyst, Springer Science + Business

Media, LLC 2009.

11- Cengiz, Blent (2013): Urban River Landscapes,Advancesin Landscape Architecture,bookedited by Murat zyavuz , ISBN 978-953-51-1167-2, Published: July 1, 2013, InTech.12- Alley WM., Thomas ER., Franke OL. (1999): Sustainability of Ground-Water Resources. U.S.Geological Survey Circular 1186. Danver; 1999.

This entry was posted inDesign,Development,Ecosystem services,Kaveh Samiei,MiddleEast,Water,WetlandsbyKaveh Samiei.Bookmark thepermalink.

2 THOUGHTS ON TEHRAN, THE CITY OF RIVER VALLEYS, NEEDS A LANDSCAPE ECOLOGICAL APPROACH TO THE DESIGN AND

PLANNING OF ITS WATERWAYS

1. Mehdi MirzaeeonJuly 18, 2014 at 09:11said:

Hi,

We are working on this issue these days in Tehran Municipality. I think that around2 weeks later we can prepare the first version of our framework. It will be mypleasure if you have any comment or idea and share with me. I will inform mycolleagues to contact you, too.Please do not hesitate to contact me by my email:[email protected].
http://www.intechopen.com/books/advances-in-landscape-architecturehttp://www.intechopen.com/books/advances-in-landscape-architecturehttp://www.intechopen.com/books/advances-in-landscape-architecturehttp://www.intechopen.com/books/advances-in-landscape-architecturehttp://www.intechopen.com/books/advances-in-landscape-architecturehttp://www.thenatureofcities.com/category/design/http://www.thenatureofcities.com/category/design/http://www.thenatureofcities.com/category/design/http://www.thenatureofcities.com/category/development/http://www.thenatureofcities.com/category/development/http://www.thenatureofcities.com/category/development/http://www.thenatureofcities.com/category/ecosystem-services/http://www.thenatureofcities.com/category/ecosystem-services/http://www.thenatureofcities.com/category/ecosystem-services/http://www.thenatureofcities.com/category/kaveh-samiei/http://www.thenatureofcities.com/category/kaveh-samiei/http://www.thenatureofcities.com/category/kaveh-samiei/http://www.thenatureofcities.com/category/middle-east/http://www.thenatureofcities.com/category/middle-east/http://www.thenatureofcities.com/category/middle-east/http://www.thenatureofcities.com/category/middle-east/http://www.thenatureofcities.com/category/water/http://www.thenatureofcities.com/category/water/http://www.thenatureofcities.com/category/water/http://www.thenatureofcities.com/category/wetlands/http://www.thenatureofcities.com/category/wetlands/http://www.thenatureofcities.com/category/wetlands/http://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/http://www.abangan.org/http://www.abangan.org/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/#comment-11663http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/#comment-11663http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/#comment-11663mailto:[email protected]:[email protected]:[email protected]:[email protected]://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/#comment-11663http://www.abangan.org/http://www.thenatureofcities.com/2014/07/16/tehran-the-city-of-river-valleys-needs-a-landscape-ecological-approach-to-the-design-and-planning-of-its-waterways/http://www.thenatureofcities.com/author/kavehsamiei/http://www.thenatureofcities.com/category/wetlands/http://www.thenatureofcities.com/category/water/http://www.thenatureofcities.com/category/middle-east/http://www.thenatureofcities.com/category/middle-east/http://www.thenatureofcities.com/category/kaveh-samiei/http://www.thenatureofcities.com/category/ecosystem-services/http://www.thenatureofcities.com/category/development/http://www.thenatureofcities.com/category/design/http://www.intechopen.com/books/advances-in-landscape-architecture


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2. Di LucasonJuly 17, 2014 at 19:31said:

sounds familiar

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