Greenways: multiplying and diversifying in the 21st century

Building on the legacy of historic greenway planning in the U.S., several new initiatives have been taking shape and gaining recognition in the past decade. One is ‘Green Infrastructure’ planning which is a ‘must have’ inter-connected system of green spaces. Another is ‘Smart Conservation’—the counterpoint of another planning initiative that preceded it known as ‘Smart Growth’. This is the establishment of critical green corridors that should be preserved and maintained for predominantly ecological functions, in advance of or in conjunction with new development. ‘New Urbanism’ has focused on bringing order and coherence to escalating ‘Edge Cities’ on the urban fringe, based on walkable, mixed-use towns, villages and neighborhoods with integrated open-space systems. Transit-Oriented Developments (TODs) are transportation plans for accommodating regional growth around clustered ‘pedestrian pockets’ linked by transit systems. Both New Urbanism and TODs have applied similar principles to ‘brown sites’ and declining city neighborhoods.All these initiatives are different aspects of the greenway movement, expressing its many possibilities, enriching its original concepts, enlarging its credibility—if need be—and emphasizing its importance for and relevance to current issues of sustainability and ‘green’ planning and design. The author, a teacher/practitioner, discusses recent U.S. greenway examples at site, metropolitan and regional scales for which he has been the principal planner/designer or a consultant, and compares New Urbanism and TOD methodologies and approaches to established greenway-planning practices and the premises of Smart Conservation.     

Greenways, blueways, skyways and other ways to a better London

“ Landscape planners are quick to criticise other professions for single-use planning, but we tend towards the same mistake when planning greenways and urban greenspace.” This proposition is illustrated by the great series of open space plans which was prepared for London between 1929 and 1976. It is then discussed from a theoretical standpoint with reference to Christopher Alexander, the ‘pattern analysis’ approach to landscape planning, and the author's 1991 report to the London Planning Advisory Committee, Towards a Green Strategy for London. The paper concludes that ‘greenway’ is an excellent marketing term, but that product diversification and product differentiation must take place. We need special varieties of greenway for special purposes. Brief Alexander-type patterns are outlined for seven varieties: parkway, blueway, paveway, glazeway, skyway, ecoway and cycleway.     

Greenways and the making of urban form

One aspect of greenways which is exciting popular interest in the US is the durability of nineteenth-century parkways and park systems to stitch together fragmenting cities and urbanizing areas. What the Olmsteds, Cleveland, Eliot and Kessler achieved in their regional open-space plans can be the model for a new version of Howard's ‘town/country’ in which greenways/ greenbelts/greenspaces together make a comprehensive ‘green’ infrastructure.Some of the literature and the highlights of historic greenway planning and design in the US are reviewed. Their adaptation to current projects is illustrated through a series of case studies of gradually increasing scale—villages, towns, cities and regions. Such common strategies as ‘green’ streets, parks and playgrounds structuring walkable neighborhoods, intra-neighborhood parkways connecting town/city districts, and regional park systems protecting natural areas for recreation/conservation still confer similar social, economic and environmental benefits. Whether Pedestrian Pockets or Co-housing, expanding historic settlements or preserving the countryside, planning new ‘urban villages’ or neo-traditional towns, greenways can be powerful makers and shapers of urban form at both macro- and micro-scales.     

New ‘rural lifestyle estates’ in The Netherlands

Recent studies tend to indicate that no longer all presently agricultural land in The Netherlands is required for sustainable agricultural production. Apart from various urban uses and some projects turning agricultural land into nature reserves or giving it a secondary function, like national landscape parks or drinking water supply area, it is not easy to find alternative users for the land presently managed by farmers. At the same time, many urban companies or families are vainly looking for building lots away from our ‘compact urban areas’. This paper explores a way to bring this supply and demand together in a landscape-wise more than acceptable manner: the planning concept and experiment of ‘new rural lifestyle estates’.     

Surface ozone concentrations and ecosystem health: past trends and a guide to future projections

This paper reviews current understanding of the sources and sinks of ozone in the troposphere, recent studies of long-term trends, and the factors which have to be taken into consideration when constructing and interpreting future models of ozone concentration. The factors controlling surface O₃ concentrations are discussed initially to provide a basis for the ensuing discussion, followed by a summary of the evidence for recent trends in ground-level ozone concentrations, i.e. over the past 3 decades, which have shown a significant increase in the annual average in ‘background’ air typical of the unpolluted northern hemisphere. Closer to precursor sources, although urban winter concentrations have increased, rural peak spring and summer concentrations during ozone ‘episodes’ have decreased markedly in response to emissions reductions. In order to determine whether such trends are meaningful, the statistical techniques for determining temporal trends are reviewed. The possible causes of long-term trends in ozone are then discussed, with particular reference to the use of chemistry-transport models to interpret past trends. Such models are also used to make predictions of future trends in surface ozone concentrations, but few are comprehensive in integrating future climate changes with changes in land use and in emissions of ozone precursors. Guidance is given on the likely effects of climate/precursor/chemistry interactions so that model predictions can be judged.     

Project and program diagnostics: A systemic approach

This paper focuses on the theory and application of diagnostic concepts to assess the health of large projects or programs at any point in their life relative to the desired targets. The author presents a comprehensive project health check methodology. Project diagnostics is not to be confused with project progress measurement and control or project management maturity models as the objective is to see if the project team applies a systemic approach to the planning and management of the project. Its purpose is not to assess the project progress achieved at a given time and compare that to plans. Nor does it aim to assess the maturity of the application of a particular project management methodology/standard. The health of a project/program at a given time is found by evaluating the actual practices applied to manage a raft of variables which collectively characterise the management practice on that project.The technique – referred to as project health check or ‘PH-Check’ – has been computerised for ease of application. It provides a graphical picture of the heath of a project at the time of assessment. The results of the project health check can then be correlated with the results obtained from traditional project progress measurement tools. This correlation will yield greater understanding of the management of the enabling factors and their influence on project behaviour and results. This paper presents the PH-Check methodology and its underpinning concepts.     

Natursyns model: A conceptual framework and method for analysing and comparing views of nature

This article presents a conceptual framework and methodology by which stakeholders’ views of nature can be investigated, explained, compared and ‘ideal types’ distilled based on qualitative interviews and, plans, laws and other texts analysed. The aim of such studies is to increase the knowledge about personal, social and cultural aspects of landscape and their relations in general to improve the basis of countryside planning and management in particular. Within the Natursyns model (the Danish word ‘natur’ corresponding to “nature” in English and “syn” implying perceived, imagined, cognized and culturally agreed interpretations) landscape is understood simultaneously as: ‘habitat’, unrealised sense impressions; ‘area’, all the ways in which nature is cognised; and as ‘symbol’, all types of representations of nature and its parts. The use of the model is illustrated; its epistemological foundation, the semiotics and phaneroscopy (phenomenology) of the American philosopher Charles S. Peirce, is described; the content of its fields explained; and benefits and shortcomings discussed.     

Infrastructure networks and red–green patterns in city regions

Landscape ecology challenges the urbanisation processes and the activities of the infrastructure sectors. Infrastructure networks have a strong impact on the development of cities and landscapes. This impact is often positive in an economic sense but can be negative in respect of natural or recreational functions of city and countryside. The challenge for spatial planning is to locate infrastructure lines in order to safeguard the conditions for the less dynamic functions in and around the urban regions. This paper analyses the impact of network patterns on urban development patterns and on green patterns, taking the history of the Randstad Holland as an example. In history the central peat area of this region was hardly accessible. This fact has led over the course of time to a unique spatial pattern: the major infrastructure lines and the major urban settlements are situated on the rim of a Green Heart. This creates a high-quality setting for the economy and the urbanisation of more than 6 million people as well as for natural and agricultural functions. Such a combination of urban elements and infrastructure around a green core can also be found on other scale levels and in other regions. Constraints on access often correlate with restricted urbanisation and with a sustainable position for the green elements. In those cases that such a restraint is chosen deliberately, often five phenomena are visible: (1) Polarity: a spatial polarity between less dynamic and more dynamic functions. (2) Decentrality: a side position of the main infrastructure and urban centres and a central position for the green functions. (3) Equality: equilibrium in extension of urban and rural elements. (4) Continuity: the green areas are part of larger scale networks. (5) Formality: planning policies couple the planning of infrastructure and dynamic urban activities to the development of the less dynamic, green functions.Together, these five elements create a special approach of spatial planning that can be applied on various scales. It is possible to use these elements as a concept, a design tool to create sustainable conditions for the ‘green’ functions in and around city regions. Based on some examples, suggestions are made for a strategy for urban-rural (re-)development aiming at high-quality urban life and for the natural environment, in and around urban regions. Sustainable spatial patterns demand a planning approach that combines the planning of infrastructure and urban activities with the planning of their green counterpoint.     

Integrating public safety and use into planning urban greenways

Greenways provide much-needed natural corridors and environments in urban and suburban areas, along with recreational, transportation and nature education opportunities for urban residents. However, there is a tension between the natural environment and public use in urban areas. Local residents' concerns for safety through clear sightlines and the use of lighting along trails may compromise the ecological integrity and natural character of urban greenways, whereas natural corridors in the city are often considered as being potentially unsafe, and therefore essentially inaccessible to use by many residents, particularly women, children, aging people and those with disabilities. As a result, the planning and development of safe urban trails within natural greenways can be challenging and contentious. Prospect and refuge theory provides a theoretical framework for understanding the human ecological dimensions of environmental design. Within this framework, a growing body of environment-behavior research provides useful principles for planning and designing greenways that are both ‘green’ and safe. These principles include: visibility of others, visibility by others, choice and control, solitude without isolation, and environmental awareness and legibility. This paper outlines the ‘safe communities’ approach developed in the city of Toronto, Canada, and applies it to the planning and design of trails in urban greenway systems through a series of planning guidelines, with particular reference to the Greater Toronto Area experience. The paper concludes that only when public safety is paramount will the necessary community support be built which will allow the successful integration of natural greenways into the fabric of metropolitan areas.     

Dutch experience, plans and visions

This article looks at the trends that have influenced post-war planning in the Netherlands, based on the four national development reports. The first two reports introduced the concept of the Randstad urban area and its new towns; the third concentrated on the metropolitan areas that had lost population and employment as a result of the new towns; and the fourth is influenced by current social changes and a ‘Europe without frontiers’. This latter report is offered as one of the first regional development outlines of tomorrow's Europe.     

Biodiversity dynamics: from population and community ecology approaches to a landscape ecology point of view

Species richness and species diversity are classic concepts in ecology. What is new in the science of biodiversity after the Convention on Biological Diversity is: (1) that the emphasis has moved from the species to the ecosystem; (2) that the functional significance of biodiversity has been stressed. Thus, population and community ecology along with landscape ecology, should offer the best theoretical framework to analyse what can be called ‘biodiversity dynamics’.Some promising pathways and areas are emphasized and the very concept of functional diversity is discussed. Species richness, genetic variability and extinction probability are closely linked with landscape traits such as habitat diversity, structural heterogeneity, patch dynamics and perturbations. Thus, it is suggested that landscape ecology hold a central role, since it will allow the response to biodiversity issues in the framework of environmental heterogeneity and patchiness.     

Greenway planning in Britain: recent work and future plans

The author's preferred definition of a greenway, as proposed in 1995, remains: ‘a route which is good from an environmental point of view’ (Turner, 1995). This paper is concerned with the condition of British greenway planning in the first decade of the 21st century. The aim was to discover how the concept is understood and how it is being used. A questionnaire was circulated to all local authorities in the UK. An initial set of questions dealt with definition of the greenway concept. The most supported definition was ‘A linear space containing elements planned, designed and managed for multiple purposes including ecological, recreational, cultural, aesthetic and other purposes compatible with the concept of sustainable land use’. A second set of questions dealt with the status of the greenway concept. It was found that the concept was used by 33% of authorities during the past decade but that 75% expected it to become significant during the next decade. A final set of questions dealt with a greenway project selected by the responding local authority. The typical planning period for these projects was 1997–2007 and the average length was 12.9 km. The author concludes that greenways are a landscape planning tool of considerable potential. Though comparatively neglected at the end of the 20th century, there are encouraging signs relating to the prospects for open space planning in 21st century Britain.     

Project conceptualization using pragmatic methods

An important and difficult part of project management is the conceptualization stage – particularly when dealing with multiple powerful stakeholders and ‘messy’ situations. Pragmatism provides a way forward that makes central the ‘concepts’ being used to conceptualize the project (e.g. ‘timeliness’ or ‘sustainability’). This paper argues for a sequence of two approaches suggested in the literature that combine this pragmatism and soft systems thinking to conceptualize projects. These are Alexander’s ‘Synthesis’ [1] and Checkland’s ‘CATWOE’ [2]. The first identifies concepts or worldviews, the second uses these to draft a series of ‘what needs to be done’ statements. In the way of Pragmatic Systems Inquiry, these approaches suggested from the literature are then compared to a real case study: the LC-25 project.     

Dublin

Dublin displays the characteristics of many declining industrial cities — a falling population in inner city areas, the growth of suburban areas, a planning system which displays the features of ‘muddling through’, and proposals for growth to occur at the metropolitan periphery. However, it is viewed as essential to preserve the multifunctional role of the inner city area. The pressures on this area are significant — in many cases a legacy of 19th century problems. There has been an inability to implement coordinated development plans, although the Eastern Region Development Organisation should provide a planning framework for the first decade of the next century.     

Buffering external threats to heritage conservation areas: a planner's perspective

This paper centres on the fundamental issue of environmental conservation from a planning perspective. For many years planners have been criticised for not integrating conservation with the need for development with one usually occurring in isolation to the other. Thus, this paper reviews environmental planning to disclose a gap that may exist in current practice in relation to protection of cultural heritage places from threats generated within their surrounds.As conservation of the built and natural environment confronts in practice common problems, it is suggested that a technique applied in natural heritage protection to ‘buffer’ national parks from external threats occurring outside the legal bounds of protected places can be adapted to the urban environment in the protection of cultural heritage. This technique is the buffer zone planning (BZP) technique developed by Kozlowski and Ptaszycka-Jackowska.From the limited application that has been undertaken of the technique as applied to heritage conservation and which is summarised here, it is evident that the technique shows certain strengths suggesting that with further development BZP may become an important planning tool in conserving built heritage. This paper therefore presents the findings of this application in the hope that it will generate constructive discussions in relation to the technique in an urban application.     

Wild times and domesticated times: the temporalities of environmental lifestyles and politics

In this paper, I explore how environmental movements and lifestyles, like all forms of human action, produce their own characteristic kinds of time. During this exploration, I introduce a number of concepts which I suggest are useful in understanding these temporalities—chronological and kairological time; linear and cyclic time; segmentation and plot; orientation and synchronisation. Whereas the environment as described by the natural sciences is one dominated by chronological, linear time, human time is also kairological, suffused with meaning and intention. The varieties of human action also produce their own distinctive temporalities—some linear, some cyclic, some oriented to external goals, some self-sufficient. The logic of kairological time also requires that we understand individual events and actions as ‘figures’ against a temporal ‘ground’—one that is characteristically organised into an overarching narrative, or broken up into distinctive time segments. Furthermore, human experience is not just situated in time, but orients itself within time—it faces ‘backwards’ into the past, ‘forwards’ into the future, or commits itself to the present. Finally, lived time is also sometimes synchronised with other times—with that of proximate or distant others, or with historical narratives of progress or decline.     

Fragmentation and cultural landscapes: tightening the relationship between human beings and the environment

Fragmentation is a research concept properly belonging to the biosciences and agriculture, yet it is one finding application in the planning and design fields. Cultural landscapes, on the other hand, is a concept uniquely rooted in landscape architecture and resource management. This paper links the two as a means of better grounding each in the decisions and processes affecting countryside planning and rural landuse, although both concepts have applications in urban settings, as well. However, in theory and in practice, both concepts are impacted by the man versus nature paradigm, in which planners and designers are challenged to consider whether human actions are “natural” actions, or whether they belong in a separate philosophical category. This position paper was developed as a keynote speech for the 2000 ISOMUL Conference at the Wageningen University and Research Center in The Netherlands.     

结合专业知识背景的城乡规划专业植物景观课程内容设计——以北京林业大学为例

园林植物是构建城市生态或区域风貌的重要内容之一,也是城乡规划从业者需要掌握的基础知识。但传统城乡规划教学体系尚未对此模块有较为完善的设置。以北京林业大学为例,从城乡规划植物景观课程的变迁和实践探索入手,结合课题项目与教学经验,不断改进课程设置。以期从城乡规划知识背景为出发点,通过对“城乡规划植物景观”课程教学组织的优化,达到加强学生对树种类型及空间分布、植物生境及生长状态、树种类型与文化背景、居民生活与优势种植、历史发展与城市变迁以及植物景观与区域风貌等方面的认知和应用能力,实现从课堂教学到实践应用的转化。     

‘Management by projects’: the management approach for the future

The trend toward the project-oriented company, performing simultaneously a network of internal and external projects, creates the demand for the management approach ‘Management by Projects’. The specific feature of ‘management by projects’ is that the management of single projects, the management of the network of projects and the management of the relationships between the company and the single projects are considered. For the successful management of the project-oriented company, instruments of ‘Management by Projects’ are presented.     

Resilient cities: meaning, models, and metaphor for integrating the ecological, socio-economic, and planning realms

Urban designers, ecologists, and social scientists have called for closer links among their disciplines. We examine a promising new tool for promoting this linkage—the metaphor of “cities of resilience.” To put this tool to best use, we indicate how metaphor fits with other conceptual tools in science. We then present the two opposing definitions of resilience from ecology, and give reasons why one is more appropriate for linking with design. Additional specific tools and insights that are emerging from, or being increasingly used in, ecology can further support the linkage with urban design. These include recognizing the role of spatial heterogeneity in both ecological and social functioning of urban areas, the integrating power of watersheds, social and ecological patch dynamics of cities, the utility of spatial mosaic models to capture function, the use of an integrated “human ecosystem” modeling framework, and the consequent perspective of metropolitan areas as integrated ecological-social systems. Three additional tools are related to the adaptability of people and human institutions. First is the recognition of a “learning loop” in metropolitan ecosystems in which people respond to and affect ecological change, the use of urban design as experiments whose ecological and social outcomes can be measured, and finally the potency of a dialog between professionals and citizens, communities, and institutions, to support both research and design. The metaphor of resilience, and its technical specifications, draw these diverse strands for linking ecology and planning together.