24 may. 2016

The history of Urban Ecology in cities

Ecological and environmental management principles in the urban planning context seems to be a revolutionary concept and non intuitive at all. The good news is that these notions have been in the urban agenda for decades. Nowadays cities face serious environmental challenges such as climate change; air, water and soil pollution; loss of biodiversity, among others. They also face a reduction of supply of natural resources such as water and energy, due to increasing urbanization patters. In this sense and looking forward to the future, is important to understand how environmental concepts have been included in city planning and development for the last 40 years.

It was the year 1969, when Ian L.McHarg published his book Design with Nature, introducing for first time the relationship between landscape architecture, urbanism and ecology. He described several challenges in this relationship. First, the absence of any knowledge between environment and planning, secondly a lack of integration within the proper environmental sciences (geology, meteorologists, hydrologists, ecologists, biologists, etc) and finally several deficiencies attempting to address the problem of human adaptation in cities. All efforts were separated and isolated and the book made a contribution to try to overcome them. For first time the concept of a method by which environmental data could be incorporated into the planning process in cities was introduced.

In addition to this, Design with Nature was one of the books that supported the inclusion of maps development and overlapping in the process of the environmental impact assessment for any project development. This book was written in a moment where environmental hazards and problems were not clear to the human eye. No information was available on disasters such as Bhopal, Love Canal, Etzon Valdez, nor evidence on climate change, ocean level rise or ozone depletion, was offered.  In this sense, this book constituted a milestone in the inclusion of environmental criteria in the urban and national planning processes.  After 20 years, the author Mc.Harg did a review of his book and he stated that “a dream in 1969, it is in 1991 a practical possibility”. I believe he was right. Nowadays, almost all the development of any project require an environmental impact assessment, and most of cities consider ecological and environmental aspects in their planning processes.

The book introduced principles of Urban Ecology and concepts as preservation, management, landscape, culture, tradition, innovation, theory and practice. It showed the example of New York and Staten Island as a failure in terms of the lack of inclusion of these principles the city future design. Natural resources and landscape features such as mountains, forests and the ocean, were removed from the city scenario during urban planning processes. Their inclusion in the city master plan would have been crucial for city sustainability nowadays. The opportunity was lost and what it would have been splendid if these features would still be part of the city. The author notes with melancholy this loss, and how urbanization and human occupation have changed the city landscape and natural processes.

Design for nature, also includes an analysis of the relationship between social values, land and natural processes and establishes several examples in this matter. A flat land with good surface and soil drainage can be suitable for intensive recreation or commercial-industrial development activities. Areas of diverse topography can be suitable for passive recreation and/or residential development.  L. McHarg, introduces a method to evaluate how land use can be defined and can be affected by several factors like; geology, tidal inundation, water-table, forests extensions, air pollution, slopes, drainage, erosion, etc.  This method includes an evaluation of more than 30 factors that could have influence in five (5) types of land use: Residential Development, Commercial-Industrial Development, Conservation, Passive Recreation and Active Recreation.

This analysis gives insights of the suitability of different areas for particular activities and also highlights the importance of this evaluation for city planning.  The method is supported by coloured thematic maps of the aspects evaluated and the influence on land use.   In addition, the method could give a guide for the the identification of areas that can be suitable for different land uses at the same time. Although this can be seen as a challenge or an opportunity, this will depend on the city and the type of land uses, culture and social aspects of the city.

To complement this method approach, Michael Hough in his book City form and Natural Processes, goes beyond the concept of Design with Nature, and introduces the term urban ecology as a basis for city design. Within this principle, two aspects should be covered. The first one related to the need of an environmental view for urban design and secondly the recognition that environmental problems have their origin in cities, and consequently solutions must be sought in them. He also mentions that there are two landscapes that co-exist in cities. The first one, related to the “pedigree” landscape of beautiful parks and planned gardens and places for people to meet or mainly for civic purposes. The second, the natural landscapes of not that beautiful places, which may be forgotten places of the city. For example, places flooded after rain or abandoned industrial places in the city.  In this sense, Hough suggests to develop urban planning activities merging both landscapes, including environmental thinking and promoting social cohesion.

The use of urban spaces should reflect the attitudes and values of people in relation to the places they live in. But some cities have been also influenced by external factors such as rapid urbanization and industrialization. Others instead have kept their landscape and original character. In all of them social interactions take place: business, parks, markets, small stores, walking places, etc.  All these activities affect the landscape and are sometimes are disconnected to the countryside realm and vice versa.  In the city, the natural services are not seen nor valued creating a disconnection between the city and the countryside.  For example, the user does not know the water source that is providing potable water through the tap. This disconnection can be restored with the design process that includes the concept of urbanism and ecology, introduced by Hough.

The design principles in urban ecology by Hough, can be applicable nowadays. Initially, this design should have an understanding that urban landscapes are not static.  Secondly that the nature of landscape design should include man as its most important aspect.  It differs in concept from conservationist view of cities –where nature is first- and it suggests that change in landscape can be constructive and improve citizens’ quality of life.  Another principle is economy of needs, introducing the concept of efficiency and resource optimization. Municipalities expend a lot of money in infrastructure and works for the city, so this must be used efficiently. In addition, the design should also promote diversity in all it senses, including physical, biological and human aspects.  In a city there must be diverse places to meet citizens needs.  Another principle introduced by Hough refers to environmental education on natural systems and cities especially to children and on a community level. The final principle in this process of Urban Design, includes human development and enhancement of the environment.  This consideration aims to make clear that any activity causes a disruption on the environment and should be taken into account for planning purposes.

This concept of urban ecology has been used in different cities of the world. In 2006, Konjiaan Yu, introduced the concept of the relationship between landscape architecture and its environmental implications. He stated that landscape have been commercialized in a “industrialized, motorized globally connected society” but it can  be the basis to promote landscape design projects in harmony with nature, and with people in mind. This design should also have “spirits in mind”, connecting land and people as individuals.  Landscape architecture may also play a significant role in dealing with big environmental and survival issues. For example, floods, draughts, soil erosion, water management, the protection of biodiversity and cultural heritage, urbanization and land resources management. 

Urban Ecology and Landscape Architecture principles, have been fostering city planning with a long term vision in the last decades. They have anticipated in some extent urban environmental challenges and have identified relationships that simple urban planning has not been able to realize. They were aimed to promote environmental and socially healthier cities but still there is long path to go. 

The contributions of Ian L. McHarg, Michael Hough and Konjiaan Yu, reflect how throughout the last four decades, the inclusion of environmental aspects have shaped urban planning strategies silently and with restricted success. Now, we know that environmental sciences must support urban design processes in cities, as now they face serious natural resources constraints (i.e water or energy) and high pollution levels. Urban Planning can not be seen as an isolated subject anymore and with the only responsibility of architects and urban planners. Other professionals, especially environmental experts must take part of city sustainability planning initiatives worldwide.