Urban Green spaces refer to those land uses and land cover that are covered with natural or man-made vegetation in the city and planning areas. It has been long argued about the definition of green space system. Different disciplines have used various definitions from their own professional concept, such as Horticultural Greenland System, Urban Greenland System, Ecological Greenland System, and Urban Green Space and Green Open Space (Manlun, 2003).
Common is that they are primarily linear or networks of linear lands designated or recognized for their special qualities Table 1. 1 (Hellmund and Smith, 2006)
|
TERM |
OBJECTIVE OR CONDITION |
EXAMPLES |
|
Biological corridor (biocorridor) |
Protect wildlife movement and accomplish other aspects of nature conservation. |
Mesoamerican Biological Corridor through Central America; Chichinautzin Biological Corridor, State of Morelos, Mexico |
|
Bioswale |
Filter pollutants from storm runoff (usually at the scale of a site). |
Numerous examples in various localities. See, for instance, the bioswales that are part of the City of Seattle Public Utilities’ Street Edge Alternative (SEA) project in northwest Seattle. |
|
Conservation corridor |
Protect biological resources, protect water quality, and/or mitigate the impacts of flooding. |
Southeast Wisconsin environmental corridors |
|
Desokota |
Blend rural and urban areas in a dense web of transactions, tying large urban cores to their surrounding regions in the same landscape. (From the Indonesian words ”desa, ” for village, and ”kota, ” for town. Also known as the McGee – Ginsburg model. ) |
Indonesia and China |
|
Dispersal corridor |
Facilitate migration and other movement of wildlife. |
Owl dispersal corridor in the Juncrook area of the Mt. Hood National Forest in Oregon; Marine dispersal corridors for blue crab in the Chesapeake Bay |
|
Ecological corridors (eco-corridors) |
Facilitate movement of animals, plants, or other ecological processes. |
North Andean Patagonian Regional Eco-Corridor Project |
|
Ecological networks |
Facilitate movement or other ecological processes. |
Pan-European Ecological Network for Central and Eastern Europe |
|
Environmental corridor |
Protect environmental quality. |
Southeastern Wisconsin environmental corridors |
|
Greenbelts |
Protect natural or agricultural lands to restrict or direct metropolitan growth. |
City of Boulder, Colorado, greenbelt; London, England, greenbelt |
|
Green extensions |
Put residents in contact with nature in their day-to-day lives through a system of residential public greenspace, shaded sidewalks, and riparian strips. |
Nanjing, China |
|
Green Frame |
Provide a network of greenspace for a metropolis or larger area. |
San Mateo County, California, Shared Vision 2010 for the county’s future development green frame; Addis Ababa, Ethiopia, green frame |
|
Green heart |
Protect a large area of greenspace that is surrounded by development. Originally referred to a specific area in the Netherlands, but now more widely used. |
The agricultural open space surrounded by the Randstad, Holland’s urban ring, consisting of the cities of Amsterdam, The Hague, Rotterdam, and Utrecht |
|
Green infrastructure |
Protect greenspace for multiple objectives on equal grounds with gray infrastructure (i. e. , roads, utility lines, etc. ). |
Maryland Greenprint Program; Chatfield Basin Conservation Network— Denver, Colorado, metropolitan area |
|
Green fingers |
Purify stormwater through bioswales. |
Buffalo Bayou and Beyond for the 21st Century Plan, Houston, Texas, area |
|
Green links |
Connect separated greenspace. |
Green Links initiative to connect isolated patches of habitat throughout the lower mainland of British Columbia |
|
Greenspace or green space |
Protect lands from development. |
Countless systems (usually called "open space") across North America |
|
Green structure or greenstructure |
Connect separated areas of greenspace and provide a structure around which development may occur. Term is commonly used in Europe. |
Greater Copenhagen Green Structure Plan |
Green Belt land is contributing to the healthy ecosystems which underpin many natural processes supporting a range of services including pollination, soil fertility, flood defense, air filtration and carbon capture and storage. Without the Green Belt designation it is likely that a proportion of this land would have been lost to urban development and associated infrastructure. Green Belt landscapes have been fragmented by development in a number of locations over time, however, and there may be a correlation between this and the relative lack of large and/or nationally important nature conservation areas. Green Belt land needs to be recognized as an integral part of ecological networks, forming healthy, functioning ecosystems to benefit wildlife and the people who live in adjacent towns and cities (Anonymous, 2010).
|
Fig. 1. Green belts in England (http://www. buildinglanduk. co. uk/greenbelt-land-uk. htm) |
Greenways are being designated as green network in cities and countryside throughout North America and elsewhere. Sometimes these conservation areas are a response to environmental problems, such as flooding or degrading water quality. Other times their creation is an act of pure vision— people imagining a better community— one where people and natural processes coexist more closely. Often, despite this recent popularity, people fail to recognize the full range of contributions greenways can make to society and the environment. It is as if open spaces, especially in metropolitan areas, have been thought of as just so much generic greenery, mere backdrops for people’s activities. In this chapter we suggest why greenways are deserving of their newfound popularity and how their functions can be enhanced, but also consider their limitations. We discuss how the greenway concept came to be, how it has been defined, and how its spatial form and content have varied. We also highlight the significant social and ecological functions of greenways, in advance of a fuller discussion of greenway ecology and design in subsequent chapters (Hellmund and Smith, 2006).
A network of green spaces which supply life support functions including food, fiber, air to breathe, places for nature and places for recreation. The Green Infrastructure approach seeks to use regulatory or planning policy mechanisms to safeguard natural areas. Multifunctional green infrastructure refers to different functions or activities taking place on the same piece of land and at the same time. For example, a flood plain providing a repository for flood waters, grazing land, a nature reserve and a place for recreation (Anonymous, 2010).
