Global Visions: Risks and Opportunities for the Urban Planet Topic : Planning for Ecological and Sustainable Green Areas Siriwan SILAPACHARANAN, Nawanat OSIRI, Kaweekrai SRIHIRAN, Yongyuth JANYARAK Chulalongkorn University, Thailand 1. Background and rationale Bangkok and other cities are facing more severe deteriorated ecosystem while the number of population is increasing. Therefore, the Faculty of Architecture with the support of the Office of Environmental Policy and Planning carried out a research project targeting the enhancement of the urban quality of life by including measures to increase green area based on the concept of sustainable ecosystem.
2. Goals 1) Plans and prototypes of environmental quality development in relation to green areas which can effectively be used to manage green areas in the community in compliance with the sustainable development of the country. 2) Standards of management of green areas in municipalities all over the country. 3) An application program together with a database of different types of green area in municipalities all over the country which is easily accessible. 3. Concepts of management for ecologically rich and sustainable green areas Definition of terms The term ‚ecosystem‛ derives from the Greek word ‘Oikos,’ meaning ‘home’. The word ‘eco’ refers to ways of living and when it is combined with the word ‘system,’ the term ‘ecosystem’ refers to the relationship between different things or different species living in the same place. Varieties of flora in the ecosystem The flora in the ecosystem can be divided into three categories as follows: 1) Trees The tree is a species of flora which is at least ten metres in height. It generally has a tiered top and it can grow to as tall as 50 metres. Trees are usually found in rainforests. Villagers believe that there is an angel living inside every tree to protect it from harm. 2) Shrubs Shrubs refer to plants that cover the forest floor. Growing no more than ten meters in height, shrubs include small plants like mosses and ferns, bushes and the seedlings of trees.
3) Vines Vines refer to plants that need a large amount of sunlight but whose trunks are not strong enough to keep them erect, so they need to creep on trees in order to reach the top and get the light they need. The plants in this group are different types of vines and ivies. An ecological and sustainable green area refers to an area that is abundant with different types of living beings connected through the food chains, hence the creation of a complete life cycle. It emphasizes preserving and growing large trees in the city, which can be in public parks, orchards, river or canal banks, and suburban groves. Biologically, ecological rich areas also refer to the areas where there is a complete cycle of transfer of energy derived from food. For example, plants use photosynthesis to change the sun’s ray into food, including leaves, wood, and flower nectar, with the first recipients of the energy being insects and herbivores. And the cycle goes on (see Figure). Sun
rotten leaves Mineral and Fertilizer in soil
Figure : Ecologically rich and sustainable green areas
4. Concept behind the creation ecologically rich and sustainable green areas Returning natural areas to the earth in order to restore balance means the search for places where ecological and sustainable green areas can be created, both in urban and in rural areas. The underlying principles behind the creation of this concept are as follows:
1) Growing a variety of plant species in the same area to reduce the competition for sunlight, nutrients and water because each species of plant has its own requirements and resilience, so each can help another. However, it is worth noting that variety here means a variation within the same class of plant. 2) Plants of the three different categories, trees, shrubs and vines, should be grown to maintain the stability and sustainability of the ecosystem. 3) Plants having different functions should be grown in the same area to ensure the richness of the area. When creating a green area in the city, measures are needed to ensure its acceptability, so that it can be regarded as a necessary factor in land utilization. This leads to the concept of the ‚ideal green city.‛ A green area replete with a sustainable eco-system refers to areas of bio-diversity with an interconnected food chain that become part of a cycle. Green areas must contain mainly perennial and not deciduous trees since these have the ability to retain carbon dioxide levels on the earth’s surface and are able to exist on their own and require minimal maintenance. The study found that it is necessary to promote an understanding of perfect green areas as well as the idea of creating the ideal and sustainable green town stipulating the necessary proportions of green areas in the composition of each town as follows: 1) Green ways referring to road spaces having 60-70% traffic surface and 30-40% green areas referring to plant bearing areas such as pavements, road curbs and traffic islands; 2) Green temples referring to temple areas allocating 20-40% for buildings and 50-60% for green areas which include 60-80% for areas reserved exclusively for monks as well as for burial grounds; 3) Green schools referring to areas providing various levels of education and allocating 40-50% for buildings and 50-60% for multi-purpose usage which includes operational space, learning centers, sports grounds etc. 4) Green offices referring to offices and other infrastructure facilities belonging to both the government and private sector allocating 50-70% for building areas and 30-50% for green areas; 5) Green houses referring to residential areas allocating 30-40% for housing space and 60-70% for green areas.
Table 1: Components of the ideal green city with the proportion of green areas to total area Component Total area (%) Construction area (%) Green area (%) Green ways 100 60-70 30-40 Green temples 100 20-40 60-80 Green schools 100 40-50 50-60 Green offices 100 50-70 30-50 Green home 100 30-40 60-70 The term ‘green space’ in the present study is not limited only to public parks. The term also refers to natural lands, river and canal banks, green spaces along the road network and green space which is accessible to all on the land belonging to the government or to the public such as temples. Table 2: Minimum standard of green space proposed for Thailand Size of the city Green space (square meter per capita) Metropolis (BMA, Regional City, Patthaya) 9 (population > 100,000) Large City 10-14 (population 50,001-100,000) Medium-sized city 15-20 (population 10,000 – 50,000) Small city 21 – 40 (population < 10,000) In developing a prototype of the management of ecological and sustainable green areas for medium-sized and small urban communities in the Mae Klong River basin, the Muang Ratchburi Municipality was selected. The representative of a small urban community is the Tambon Amphawa Municipality, Samut Songkhram Province, which is situated about 17 kilometers from the river delta. Both municipalities are appropriate as the prototype of the management of ecological and sustainable green areas, which can be applied with other municipalities with similar characteristics. Moreover, a minimum standard has been specified for green areas in relation to size of city. It is required that each citizen should be responsible for planting one perennial tree that generally cover 9 m 2 of vegetation cover. The study proposed a strategic and implementation in the management of
sustainable green area both national and local organization. Finally, a data base system for green area has to be established together with incentive.
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