Evolution of Green Space

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RIJKSUNIVERSITEIT GRONINGEN

MASTER THESIS

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Evolution of Green Space

The analysis of Green Space Change and its Driving Forces

in Bangkok, Thailand

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Author: Supervisor:

Pornchita PALACHEEVA Dr. Arie van STEENSEL

A thesis submitted in partial fulfilment for the degree of Master of Arts

in the

Digital Humanities

Communication and Information Studies 2020

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Green spaces have always been important to planet earth. Many studies report findings that support the view that green spaces have a beneficial health effect (Maas, 2006). At the time of writing this thesis, Bangkok changes beyond recognition every day, and so do its green spaces. Importantly, green spaces are considered as one of the prime objects for the urban planning of the city (Bunvong et al., 2008). According to the Bangkok Metropolitan Administration (BMA), the city counts 38,141,062 square metres (2019) of public green spaces, while the population of Bangkok is 5,680,415 (2019). This means that the ratio of green spaces per person is around 6.70 square metres, while the World Health Organisation (2012) states that the healthy amount of green spaces per person should be at least nine square metres. According to the Thai Royal Forest Department, between 1973 and 2017, the forest area decreased from 43.21% to 31.58% in the whole country. The massive changes in development, population, and the disappearance of green spaces leads to the question of what factors drive their evolution.

Before finding the answer to the this question, some general features of Bangkok should be discussed. Bangkok covers an area of 1,568.7 square kilometres in the Chao Phraya River delta in central Thailand, and has a population of over six million (The Bureau of Registration Administration (BORA), 2018), or 9.2 per cent of the country’s population. Around sixteen million people (24.6 per cent) live within the surrounding Bangkok Metropolitan Region (BORA, 2018), making it the nation’s most important city: the centre of governmental offices and commercial buildings. The consequences of being the nation’s prime city are the high density of population, insufficiency of public utilities, and high density of residential areas. Bangkok makes up 80% of the whole urbanised area of the country and growing faster than Hong Kong and Japanese urban conglomerates (World Bank, 2015). Between 2000 and 2010, Bangkok’s population growth increased with 30.9% (Bangkok Census, 2010). Like many cities in Southeast Asia, Bangkok is going through a period of massive transformation. Due to the expansion of Bangkok, investments in real estate and transport are changing the physical features of the city. In the meantime, Bangkok’s citizens are facing the fact that some of the cherished green spaces have been transformed into commercial, tourism, or residential areas. Therefore, the urban transformation of Bangkok might be the factor of changing in green spaces, and the relation between them has to be investigated.

To investigate the driving forces of evolution of urban green spaces, existing studies of green spaces in relation to the development of urbanisation and city planning are considered as a model. The study of green spaces in Greater Dhaka, Bangladesh, by Byomkesh et al. (2011), for example, concludes that the reduction of natural landscape is related to the growth in human landscape. Byomkesh’s research shows that green spaces have decreased because of population growth and increasing building density. Green spaces are used for the construction of buildings and other infrastructure for human use. He concludes that urbanisation is one of the most important driving forces behind changes in land-use and land-cover. The other study on green spaces in relation to city planning policy by Dallimer et al. (2011) discusses the dynamic change of green spaces in highly urbanised areas in the United Kingdom. The authors show that the land-use change is also subjected to government’s city planning policies, by explaining that the removal of gardens from the brownfield land category increased the development pressure on

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land outside current urban boundaries. Thus, these studies show that the development of urbanisation and city planning encourage the change of green spaces.

The previous studies on green spaces evolution in relation to urban development in Bangladesh by Byomkesh et al. (2011), and green spaces evolution in relation to city planning Dallimer et al. (2011), raises the question as to whether Bangkok experiences the same occurrences as in England and Bangladesh? Did its green spaces change, or not? And if they did, how and why? In addition, green space development in Bangkok between the early twentieth century and now has not been noticed in the academic field. Green space also has been playing an important role in Thai society as it gives the environmental benefits, economic and aesthetic benefits, and social and psychological benefits (which will be discussed later in chapter I). Hence, it is necessary to determine how green spaces developed in years, and to assess what forces changed green spaces. Moreover, the digital method that I used in this thesis will be beneficial for those who will conduct research on similar topics in the Humanities and Geography. In sum, this research investigates the evolution of green spaces in Bangkok during a period of thirty years (1988-2018), as well as to test the conclusions drawn by previous studies that there is an impact of urban development and city planning on the evolution of green spaces.

To achieve this objective, the key concepts are set as 1) green spaces 2) urban development and 3) city planning. The research will explore the relations between these key concepts. The theoretical models that will scope my study will be based on the previous studies on the urban development and city planning effects towards green spaces by Byomkesh et al. and Dallimer et al. According to the previous findings, green space development can be affected by the urban development (e.g. level of built-up area) and city planning (e.g. the land-use policy). In addition, the findings and models from the previous studies helped me develop the research questions as follows:

•What are the definitions of green spaces?

•How have green spaces in Bangkok evolved over the past thirty years?

•How does the evolution of green spaces relate to levels of the built-up area?

•How has city planning affected the change in green spaces?

To answer the research questions, I examined Landsat’s satellite images of Bangkok which reveal green spaces and other land uses. The satellite started to continuously capture the images of Bangkok every year since 1987. Hence, I started to look into green spaces of Bangkok from 1988 to 2018 according to the data’s availability. According to the previous studies by by Byomkesh et al. and Dallimer et al, I issued the level of built-up development as an important factor on choosing the study areas, since I expected that the evolution of green spaces in less built-up area and more built-up area will be different. The study areas are firstly chosen based on Bangkok’s comprehensive plans and population densities. As a result, a highly urbanised area, a suburb, and a commercial area were chosen. First, I will define and explain the green space definition, green space roles, and general information on Bangkok’s green spaces. Second, satellite images of three study areas will be analysed to categorise their land uses, including green spaces by using analysing tools from ArcGIS. The tools allow me to indicate types of land

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use in satellite images in size. The results of satellite images analysis will be annotated and stored for the visualisation. In chapter two, I will create visualisations of green spaces evolutions of three study areas in thirty years (1988-2018), which will help the readers to understand the results better. The visualisation will be created by Python programming, which allows me to create graphs and figures of large datasets conveniently and effectively. In chapter three, I will explain the relation between development of green spaces and built-up areas by using visualisation. Lastly, City planning and Bangkok’s comprehensive plans will be investigated to see their policies on green spaces, and then I will compare the results of land-use evolution with the city plans to see if city planning affects the change of green spaces.

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Chapter I: Definitions and Literature Review

Green spaces have to be defined in order to begin the empirical analysis. For a better understanding, this chapter will explain the definition of green spaces. The roles of green spaces are described, as well their function in Bangkok, which can lead to a better understanding of how and why the green spaces change. Furthermore, I will point out literature reviews of the previous studies on green spaces shift in relation to urban development and city planning to create a starting point of the thesis. Lastly, I will explain the evolution of city planning in Bangkok.

1.1 Defining Green Spaces

Unquestionably, green space is defined as a vocabulary by Merriam-Webster as a community

space consisting of land (such as parks) rather than buildings, which it is widely comprehended

by people in general. In this research, it is required to define the meaning of green space to scope the limitation of the analysis.

According to a review of the meanings of “green space” in Defining greenspace: Multiple uses

across multiple disciplines (Taylor & Hochuli, 2017), most publications fail to define what is

meant by the term “greenspace” or ‘green spaces’. Some papers provide examples of green spaces, for instance, “woodlots, parks, gardens, road strip corridors, golf courses, and cemeteries” (Carbo-Ramirez & Zuria, 2011), but every paper relies on different examples of green spaces. For instance, some examples include domestic gardens (such as Dallimer et al., 2011), while others exclude domestic gardens (such as Cummins & Fagg, 2012).

The definitions of green space by Carbo-Ramirez & Zuria (2011), Dallimer et al (2011), and Cummins & Fagg (2012) were defined individually by the authors to support their research. It shows that the definition of ‘green space’ is defined in various ways in the literature. However, the given definitions can be commonly known by the readers as they commonly used words such

parks and gardens. In addition, green space can be distinguishably used in a term of green space bipropellant (Kang, Jang, & Kwon, 2016, pp. 209-214). However, it does not refer to vegetated

land, but rater to to an environmentally-friendly form of space propulsion (Kang et al., 2016). Moreover, Greenspace is a compound that, unlike a noun phrase such as purple shirt, has a distinct meaning (Verhoeven & van Huyssteen, 2013), such as whiteboard, which is not just a board that is white, but an erasable board that is used with markers for presentations. The literature also states that acknowledge that greenspace will be used in varying disciplines, cultures and contexts. Hence, it is not useful to try and impose a single definition for common terms such as greenspace across all contexts. Instead, scholars suggest that by providing a meaningful definition of what the term means for each study, greenspace might be understood across disciplines, cultures and contexts.

Greenspace has another specific meaning. In city planning, it specified the zoning of land use which defined the “green space” in more specific meaning. Green spaces are for the reservation

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of the agricultural area since they have been defined by the law as a perfect land for agriculture (e.g. the land which consists of high-quality soil), including to control the building construction and land use that will have negative influences on the agriculture. These green spaces that were determined by the local legislation or the law are called the green belt. Bangkok’s Department of City Planning uses a green belt as the term referring to green spaces in their legislation and laws (Office of the National Economic and Social Development Council, 1986).

Despite that green spaces can be defined in several meanings, in this thesis green spaces are defined to analyse their evolution in Bangkok. Thus, they will be defined as the areas that appear in green colour in the satellite images. It will be based on my justification whether the green area in the satellite images can be identified as the vegetated lands which are environmental-friendly, which can be:

• open space which its surface is comprised of street trees, parks and gardens • vegetation cover (forest, grass field, shrubs, and others)

• cultivated lands (agricultural areas, crop field, fallow lands)

• green roofs (roof of a building that is partially or completely covered with vegetation) • street trees

• landscapes • cemeteries

Moreover, the definition of green space from the city planning will be considered as well, which are agricultural areas and other green areas that appear on Bangkok’s comprehensive plans.

1.2 The Role of Green Space

The provided examples of green space definition implied the role of green spaces within the word itself such as the agricultural lands: the land devoted to agriculture, or the examples that require the purpose of their existence such as green roofs or the street trees. Knowing the benefits of green spaces can reflect on the importance of green spaces towards society: why one society needs such these green spaces in their lands? The general roles of green spaces which have been described by Karadi et al. in The Role of Green Space for Sustainable Landscape

Development in Urban Areas (2017). Under this topic, the three main aspects of green spaces

which are categorised as 1) environmental benefits 2) economic and aesthetic benefits, and 3) social and psychological will be distinctly described.

1.2.1. Environmental benefits

The environmental benefits of green spaces are, firstly, a reduction of air pollution. Secondly, green spaces serve as a protection centre for species breeding and plant conservation, soil and

water quality preservation. Thirdly, they provide ecosystem services to the city. Lastly, green 1

Ecosystem services: represent the direct and indirect benefits that people derive from ecosystems (MEA

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2005), and therefore they play an important bridging role in connecting human systems with ecological systems (Fischer et al. 2012, Martín-López et al. 2012).

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spaces assist in reducing the condition of the urban heat island effect. The four aspects of green space’s environmental benefits are clarified hereafter (Karade et al, 2017).

Urbanised areas are often hit by pollution. The pollutants involve chemical substances, particulate matter, and biological materials in the form of solid particles, liquid droplets, or gases. The most common pollutions in the urban region are noise pollution and air pollution: carbon dioxide, carbon monoxide, sulphur dioxide and nitrogen oxide, which are largely produced by motor vehicles and factory emissions. Sulphur dioxide and nitrogen oxide are very toxic to both humans and the environment. Children, elderly and people with respiratory issues are the most group of people who get impacted by such detrimental contaminants (Herzele & Wiedemann, 2003). Green space can directly reduce air pollutions by trapping the dust and smoke particles on its vegetation. Research has shown that it is possible to filter an average of 85% of air emissions in a park (Bolund & Humhammer, 1999). Traffic and other sources of noise pollution can be stressful and create health issues for people who are living in an urban area. In overcrowded cities, green space can significantly reduce noise levels, depending on their quantity, quality and distance from the source of noise pollution. Preserving urban green space to protect a natural ecological network for the sustainability of the environment in cities in the studies on urban green space considering the complex urban ecosystem.

Green space also serve a function as a protection centre for species breeding and plant conservation, soil and water quality preservation. Urban green spaces provide a connection between urban and rural areas. They offer visual relief, seasonal change and a connection to the natural world (Marcus et al., 1997, cited in Karadi et al., 2017). Moreover, a functional green space network is important for the preservation of ecological aspects of a sustainable urban landscape, with greenways and plant species adapted to local conditions with low maintenance costs, self-sufficient and sustainable (Loures et al., 2007)

Urban green spaces provide ecosystem services to the city ranging from biodiversity maintenance to urban climate regulation. For example, there are differences in solar input, rainfall pattern and temperature between urban regions and rural regions. Furthermore, due to the built environment, solar radiation, air temperature, wind speed and relative humidity vary significantly in cities (Heidt & Neef, 2008).

In addition, urban heat island effect (UHI) can occur at the large area of heat-absorbing surface, in combination with high energy consumption in the city. This effect can increase urban temperatures by 5 degrees Celsius. Hence, an appropriate forest plantation, vegetation around the urban residences, water management by the official can assist in reducing the condition of the urban heat island effect (Bolund & Sven, 1999).

1.2.2. Economic and aesthetic benefits

Green spaces provide economic and aesthetic benefits. First, green spaces can assist with the cooling of structures. Second, green spaces increase the level of aesthetic delightfulness and attractiveness to residents and investors.

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The use of vegetation to decrease the energy expenses of cooling structures has increasingly been acknowledged as a cost-effective reason to increase green space and tree planting in temperate climate cities (Heidt & Neef, 2008). Plants enhance the air circulation, provide shade and evapotranspiration. Having enough plants also provides a cooling effect and helps to lower air temperatures, i.e. a park of 1.2 km by 1.0 km can produce an air temperature that can be detected up to 4 km from the park and the surrounding city (Heidt & Neef, 2008). Research in Chicago showed that growing tree cover in the city by 10% could decrease overall energy for heating and cooling by 5 to 10% (Sorensen et al., 1997).

City areas with enough greenery are aesthetically delightful and attractive to residents and investors. The embellishment of Singapore and Kuala Lumpur, Malaysia, was one of the variables attracting the foreign investors, which they assisted with the rapid development of the economy (Sorensen et al., 1997). However, there are strong indicators that green spaces and landscaping increase property values and financial returns for land developers by 5-15% depending on the type of project (Heidt & Neef, 2008).

1.2.3 Social and psychological benefits

Green spaces also play the role of the social and psychological benefactors to society. They can be relaxing resources for citizens in the neighbourhood. In the following paragraph will be the clarification of how green spaces can fulfil the needs of the residents around the green space area in both social and psychological ways.

People fulfil most of their recreational needs within the neighbourhood they live in. The majority of a country’s population lives in urban regions, and thus green spaces provide a sustainable quantity of the total outdoor recreational possibilities in urban regions. Research undertaken in Helsinki, Finland, stated that during the year almost all (97%) urban residents engage in some outdoor leisure. Half of the residents make daily or every second day outdoor visits (Neuvonen et al., 2007). Urban green spaces serve as an almost relaxing resource; provide emotional warmth (Heidt & Neef, 2008). The central Chapultepec Park in Mexico City attracts up to three million visitors a week being entertained by a wide range of activities (Sorensen et al., 1997).

Furthermore, people who are neighbouring to the natural environment are reported that their stress levels fell rapidly compared to people who live under an urban environment, which their stress levels remained high (Bolund & Sven, 1999). In addition, patients in a hospital whose rooms faced a park had a 10% quicker recovery and required 50% less pain-relieving medicine than patients whose rooms faced a construction wall. This indication states that green spaces can improve the well-being of urban citizens both physically and psychologically. In another research carried out in Swedish cities showed that the more time a person spends outdoors in green areas, the less stress they are affected (Grahn & Stigsdotter, 2003). Thus, improvements in air quality by maintaining the vegetation certainly have a beneficial effect on physical health with such apparent advantages as a reduction in respiratory diseases. The relationship between people and nature is essential for daily pleasure, career productivity, and overall mental health (Sorensen et al., 1997).

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The given benefits of green spaces represent general advantages of maintaining green spaces in the area, including in Bangkok as well. Chanya Tiphanuka (n.d.), an agricultural researcher from the Bureau of Agricultural Commodities Promotion and Management, published an invitation to visit parks and gardens in Bangkok. The invitation suggested that green spaces are places to relax, release the stress from work, exercise to improve individual’s health, and to learn about floras and trees. Green spaces are compared as lungs of Bangkok, which they purify the air for us. Green spaces are also the preservation of the natural source. In the ending, the lists of parks and gardens in Bangkok are provided along with the invitation to point out where we can receive these privileges from green spaces.

Many organisations in Bangkok endorsed the movement to improve expand and improve green spaces according to their invaluable benefits. Since 2018, the enormous amount of PM2.5 pollution occasionally strikes in Bangkok from time to time. The air pollution creates smog and

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respiratory problems (Lefevre, 2018). It was reported in September 2019 which more than thirty-three stations for air quality monitoring have been reported that the level of PM2.5 is higher than the standard value of 50 micrograms per m3 (Pollution Control Department, 2019). However, the World Health Organization (WHO) states that the annual average of PM2.5 should not be more than 10 micrograms. As a result, the Department of Environmental Quality Promotion suggested that an appropriate amount of green spaces for citizens can reduce the amount of PM2.5 for around 7-24 per cent. While Bangkok needs green spaces, the director of the Bangkok Environment Department (2020) reported that the number of green spaces decreased in private lands due to the activities in real estate. He noted that green spaces such as public parks and garden provided by the government are maintained. In the ending, the director reported that the law on city planning regarding green spaces expansion is improving.

Even though the definition that green spaces should be environmental-friendly, green spaces provide more benefits not only for the environment. They can absorb air pollution and noise pollution, create aesthetic features for the city, which can attract the investment in the area, and uplift the citizen’s frame of mind. These benefits of green spaces are influential, and it is such why this thesis is conducted. The change of green spaces also can describe the idea of government or individuals towards green spaces of how important the green spaces are, and whether they will be emphasised.

PM2.5, which is also known as fine particles, refers to particles with an aerodynamic equivalent diameter

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less than or equal to 2.5 µm in ambient air. It can be suspended in the air for a longer period of time. The higher its concentration in the air, the more severe the air pollution is. Compared with coarser airborne particles, PM2.5 has a small particle size, so it can go through the bronchus to affect the gas exchange in the lungs, resulting in the body’s hypoxia, and thus exerting a great influence on human health. Therefore, PM2.5 is an important risk factor for lung cancer

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1.3 The Study of Changing in Green Spaces in Relation to

Urbanisation and City Planning

One of the drivers of the disappearance of green spaces is urbanisation. This concept refers to a broad-based rural-to-urban transition involving population, land use, economic activity and culture, or indeed any one of these. It is frequently used to refer to changes in land-use for specific areas (usually on the periphery of urban concentrations) as this land becomes ‘urbanised’ and is sold and developed for urban use (e.g. the sale of plots for housing) (Mcgranahan & Satterthwaite, 2014).

More than half of the world’s population is now living in towns or cities (United Nation, 2008). Increasing urbanisation is consistently blamed for the conversion of a great deal of green spaces into impermeable surfaces around the world (Nakagoshi and Kong, 2005). The infrastructures and residences are the effects from urbanisation, which increases the demands for such building and requirements of the development of lands, such as the open green areas. While two different countries, developed country (United Kingdom) and less developed country (Bangladesh) (World Population Review, 2018), according to the green spaces investigation, the two researching areas are both facing the dynamic change of green space, there are facts that lead both researching areas to outcome the results in relation between the green space and urbanisation. The study by Dallimer et al. investigated green spaces in thirteen highly urbanised areas in the United Kingdom, while the study by Byomkesh investigated green spaces in Greater Dhaka, Bangladesh, which is the most urbanised district in the country at 93%.

Interestingly, despite the fact that the cities in the United Kingdom and Greater Dhaka are highly urbanised areas, the results regarding the changing of green space are different. In the UK, between 1991 and 2006, the green space increased in almost of the studied areas (12 out of 13 cities). However, the result shows that in 2001, there was the reduction of green space in all areas. Furthermore, the population growth was greatest between 1991 and 2001 in most of the cities. While some cities did not experience the growing amount of population, instead, they experienced the falling of household size, which means the using of lands as residential areas was increased as well. Nevertheless, the green space in the UK has not been significantly decreased by the government policy (Dallimer et al., 2011). The results showed that in a long period of time (1991-2006), green spaces has increased in all thirteen cities due to the UK government planning policy in 2000 which limits urban expansion. Because of the policy, many former abandoned areas were allowed for new residential development. As a result, green spaces in thirteen cities become less again in 2008.

Meanwhile, in Bangladesh, the reduction of green spaces in Greater Dhaka has been attributed to a lack of policy, low political motivation, and poor management (Byomkesh et al., 2011). The result shows that in the study area in Bangladesh has only 8% of tree coverage, which it requires

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at least 20% of green spaces to attain a healthy urban environment (Byomkesh et al., 2011). Moreover, between 1975 to 2005, green space decreasing rates dropped from 44% to 24.1%, while the built-up areas were increasing from 13.4% to 49.4%. It suggests that a huge growth in the human landscape, which is the part of urbanisation, is related to the reduction of the natural landscape (Byomkesh et al., 2011).

The research on the Greater Dhaka and on cities in the UK reveals that the change of green spaces was affected by urban development. In addition, it shows that in Greater Dhaka while green spaces decreased, the built-up areas increased. The same occurrence also happened in highly urbanised areas in the United Kingdom, which green space size was reduced while the density of residences and population were increased. Moreover, the authors mentioned that the fall of green spaces was subjected to the lack of policy, motivation, and management. As well as in the United Kingdom, the authors also stated that a policy of removing one type of green space leads to the development pressure in the countryside.

1.4 Bangkok’s Urban Planning Evolution

1.4.1 Before the Siamese Revolution of 1932

Before 1932, there was no written Constitution in Siam. The government was an absolute monarchy. All power was vested in the hands of the king, who was in theory the master of life and death, and the owner of all land (Wright, 1908). In practice, the administration of the country was assisted by the council of ministers which they were usually from the royal family. Thus, city planning in Thailand before the Siamese Revolution of 1932 (which changed the system of government in Thailand from an absolute monarchy to a constitutional monarchy) was managed and controlled by the monarch, which he held the absolute authority to rule the kingdom at that time. Most of the city planning actions ordered by the monarch back then were given because of political stability. It is different from the present which the goal of planning is to guide the development of a city or town to be systematical, convenient, safe, and healthful for citizens and the environment (Department of City Planning and Urban Development, 2015).

An example of city planning in this era is the decentralising by King Chulalongkorn (1868-1910). In 1897, the king established sanitary districts (Sukhaphiban) and administrative divisions (Monthon) in outer areas due to that Siam was not a state, and its network cities were needed to be explicitly defined whether they were Siamese or not. The benefit of the Monthon were not only the ability to define areas as separated divisions but also to dismiss local dynasties by establishing monthons over their kingdoms. By establishing Monthon states over the old local dynasties, Siam directly held the authority over the outer states that later become monthons of Siam. The outer states were not only become the frontiers of Siam, but they also had to give up their authority over their natural resources, and they also had to pay the tributes to the central

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administration as well (Center for the Promotion of Arts and Culture Chiang Mai University, 1996).

Establishing a new local administration was not the only planning activity during the reign of King Chulalongkorn, there was also a significant change in Bangkok. This change was considered as modernisation: the king’s policy to modify and develop Bangkok into a more urbanised city using Western civilisation as a model. This modernization policy was developed to protect his sovereignty over Siam and the colonial countries against the Western countries (Wongsurawat, 2005). The imperialist countries from the western continent claimed The White

Man’s Burden: the duty of white men to make other races more civilised as an excuse to colonise

over many countries in Asia. This problem was acknowledged since King Mongkut’s reign (1851-1868) to King Chulalongkorn, his son. The king saw the modernisation as an opportunity to prevent Siam from being colonised by the western. The strategy was to develop Siam into a more modernised and civilised country. In the late 19th century, Siam was developed in many ways. In 1884, Chaophraya Surasakmontri, a Commander of the Department of the Army and businessman, brought two electricity generators from England. The generators were used to generate lights in the Chakri Maha Prasat Throne Hall at the Grand Palace for the first time (Electricity Generating Authority of Thailand, 2018). Another significant development was Ratchadamnoen Avenue: the historic road links between the Grand Palace and the Royal Palaces in Dusit Garden was the first European style avenue. The big road with traffic islands, footpaths, and trees along the street was built in 1899 with the king’s inspiration he received after visiting Europe in 1897. The other significant development during the reign of King Chulalongkorn were establishments of the first telegraph (1875), Royal State Railways of Siam (1890), and Siam Waterworks (1909). Without a doubt, the development inspired by the European culture was understandably the beginning of Bangkok’s city planning.

The beginning of city planning in Bangkok became concrete when Bangkok’s first city planning project was started in 1928. The Ministry of Justice asked permission from King Mongkut (1804-1868) to build the law school in Bangkok. According to the king’s request, Phra Nakorn City Plan 1928 was necessary to estimate the consequences of the school and its building process towards the Bangkok city (Kachen, 2015). There was several meeting during this project. The main topics during the meeting were:

1.urbanisation in Bangkok;

2.the administration, the information that was used for creating the city plan such as population, transportation, health and sanitary matters;

3.town planning of Bangkok: to make the city become the commercial area, financial area, residential area, and leisure area for the benefits of Bangkok citizens.

However, despite the fact that the law school was not built, Phra Nakorn City Plan was considered as the first concrete work on city planning that concerned with the development and attempted to understand the consequences towards the city and citizens during the city planning in Bangkok.

In overall, city planning before the Siamese Revolution of 1932 in Bangkok aimed to support political stability, which was establishing new local administration and modernising Siam. The purpose of city planning in Bangkok was different from present Bangkok that city planning mainly aims to develop the town to be more convenient and systematical for citizens and the

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environment. However, Phra Nakorn City Plan 1928 was the closest act to city planning that occurred in this period and was considered as the first existing city planning work in Bangkok.

1.4.2 After the Siamese Revolution of 1932 Era

In 1932, Siam started to be known as Thailand, went through a political transition from absolute monarchy to a constitutional monarchy. The revolution was brought by Khana Ratsadon (People’s Party) that included a small group of military and civilians. Hence, the decisions on city planning were made by the government. After the transformation of the regime, city planning in Bangkok become more apparent. There were many acts on city planning published in this period. The acts on city planning in this period took place not only in Bangkok but also in the other provinces as well, e.g. military town project in Lopburi and city planning project in Yala (Ronghanam, 2015). However, city planning in the early period was mainly focused on Bangkok’s development. For instance, In several numbers of construction control acts were announced by the parliament in 1932-1933. The main idea of these acts was to protect fire-prone areas in Bangkok and creating secureness and healthiness for the citizens, town, and environment in the area by providing the criteria for buildings construction. The acts stated that any construction and renovation in the fire-prone areas should be inquired for permission by the Department of Public Works. At the ending of the act, a map of fire-prone areas (Figure 1) was shown for a better understanding of determined zoning.

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Besides having construction control acts, the House of Representatives of Thailand issued an Act of Expropriation in Ratchadamnoen Avenue in 1939. The act was established to facilitate city planning and development in Bangkok by allowing the government to take private properties for public use such as government buildings and public facilities. The act also established several authorised committees and rules for this expropriation.

The construction control and expropriation acts represent how city planning in Bangkok continued to improve after the revolution of 1932, nevertheless, city planning acts were separately published, and there was no Bangkok city plan yet. Publishing city planning acts in this era mainly aimed to develop the area around government buildings, fire-prone areas, and temples. However, city planning in this period changed from political and military uses in the previous era to the city planning that included the development and citizen’s benefits in consideration (Ronghanam, 2015).

Until in 1952, city planning in Thailand had reached another step when the parliament published the Town and Country Planning Act 1952. There was an assumption that the act was inspired by Town and Country Act 1944 in England since two acts shared the same title and similar structure (Roachanakanan, 2015). Town and Country Act 1952 generally stated how a local organisation could legally draft their town planning, e.g. requirements of a project plan, map, and authorised committees. The act also briefly stated the purpose of town planning under section 4-C that:

•to develop a town or country area

•to provide the land

•to adjust the area into a sanitary, convenient and beneficial to the economy town

•to preserve valuable, cultural, historical, and architectural buildings, properties, and trees.

It showed that city planning in Thailand paid more attention to development and citizens and environment’s benefits. However, the act was only used in Surin province in 1954, and there was no further use of this act in anywhere since then.

Later in 1957, Litchfield Whiting Bowne & Associates, an American company was hired to study and draft Bangkok’s first comprehensive plan. To accomplish the draft, the Litchfield company suggested the Thai government to adjust the Town and Country Act 1952 to be compatible with the upcoming plan. As a result, the Department of Public Works and Town & Country Planning started to draft the new town planning act in 1959 with the help provided by the specialist from the Litchfield Whiting Bowne & Associates company.

While the new town planning was in development, the Department of Public Works and Town & Country Planning, in association with Litchfield Whiting Bowne & Associates to draft at the first comprehensive plan of Bangkok which was called the Litchfield Plan (1960). Later in 1971, they successfully published the first Bangkok’s comprehensive plan, which was known as Greater Bangkok Plan 2533 BE (1990). The 30-year plan was considered as the first comprehensive plan, which included a full version of Bangkok map, town zoning, facilities map, and transportation map. The Greater Bangkok Plan 2533 also covered the areas in Bangkok, greater Bangkok (Thonburi, Nonthaburi, and Samut Prakan). However, the comprehensive plan was hardly regulated, for the reason that Bangkok experienced rapid growth of population in that time

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(Department of City Planing and Urban Development BMA, 2015). Moreover, the new town planning was supposed to be finished before the establishment of the Greater Bangkok Plan 2533, yet the Town Planning Act 2518 BE was published in 1975 (Roachanakanan, 2015). In the same year, the government received a comment from John Friedmann, a professor at UCLA Berkley regarding the Town Planning Act 1975. He stated that the planning was not appropriate for Bangkok, giving the reasons that the preparation required too much time while Bangkok was rapidly growing in building and population density (Roachanakanan, 2015). As a result, the Greater Bangkok Plan 2533 provided the lack of some essential information (e.g. population density control, land use, building density and height, and floor area ratio) due to the fact that the Town Planning 1975 was problematic (Ronghanam, 2015). Overall, Greater Bangkok Plan 2533 was the first modern comprehensive plan comparing to the previous city plan.

Despite the unsuccessfulness of Greater Bangkok Plan 2533, the Thai government continued to enforce the Town Planning Act 1975. In general, the new town planning act shared similar content with the Town and Country Act 1952. Nevertheless, it became more meaningful by stating the meaning of “town planning”, “comprehensive plan”, “specific plan”, building”, “accessory land”, “open space”, and “town planning officers” under section 4. The acts were also explicit on the process of committees authorisation and town planning. The act became democratic when each town planning required public advertisement and a forum to hear comments from local citizens under section 27. On the town planning committee part, not only the Department of Public Works and Town & Country Planning were the committees but many departments also took place in the town planning as well, e.g. Ministry of Interior, Ministry of Agriculture and Cooperatives, Ministry of Transport, and Ministry of Industry. Hence, the Town Planning Act 1975 was the first explicit town planning that citizens and many departments were involved in the planning.

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Map 2: Greater Bangkok Plan 2533 (1st_{Revised Version)}

Source: Department of City Planing and Urban Development BMA

Later in 1992, Greater Bangkok Plan 2533 was modified and called Bangkok Comprehensive Plan 2535 under the Ministerial Regulation 116. The five years old city plan was adjusted to support the increase of population in Bangkok. In 1999, the same city plan was adjusted and called Bangkok Comprehensive Plan 2542 (1st Revised Version). This plan was revised two times later in 2006 (2nd Revised Version) and 2013 (3rd Revised Version) to support the increase of urbanised areas in the greater area of Bangkok. Since the Bangkok Comprehensive Plan 2542, the comprehensive plan consists of the Land Use Zoning Plan, the Transportation Plan, and the Open Space Plan. In the latest version (Bangkok Comprehensive Plan 2556), the Public Utility Plan was added as well. The other necessary components for city planning were added as well,

e.g. Floor Area Ratio (FAR) and Open Space Ratio (OSR) . 3 4

Floor Area Ratio (FAR) is the measurement of a building’s floor area in relation to the size of the lot/parcel

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that the building is located on. FAR is expressed as a decimal number, and is derived by dividing the total area of the building by the total area of the parcel (building area ÷ lot area)

Open Space Ratio (OSR) is any area on a zoning lot that is open to the sky from its lowest level. In certain

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circumstances open space may include covered areas.

Residential Areas (low-density) Residential Areas (medium-density) Residential Areas (high-density) Institutes and Universities Commercial Areas Public Facilities Warehouses Industrial Areas

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Map3,4 : Land Use Zoning Plan in Bangkok Comprehensive Plan 2542 (1st_{Revised Version) and}

Land Use Zoning Plan in Bangkok Comprehensive Plan 2556 (3rd_{Revised Version)}

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By the time of writing this thesis, Bangkok Comprehensive Plan 2556 (3rd Revised Version) is still the current city plan that Bangkok is using. This version was considered as a complete version that contained all of the components which were required in the Town Planning Act 1975 (section 17):

• purpose of the city plan

• map(s) with these specifications: land uses, open spaces, transportation, public facilities,

descriptions and legends of the map(s), and policies to goal’s achievement.

Bangkok Comprehensive Plan 2556 (Map 4) states the purposes of providing a better quality of life to citizens, to become the financial and commercial centre, to preserve the nature, to provide better transportation, to maintain the balance between residential areas and workplaces, and to create more green spaces (Department of City Planing and Urban Development BMA, 2013).

The plan also added Biotope Area Factor (BAF) to support the development of green spaces as 5

well. Moreover, the similar change was stated in this version of Bangkok plan that the lower density of residential area was turned into a higher density of residential areas, and the commercial areas were increased in the map as well.

This latest version of Bangkok Comprehensive Plan was enforced to be legally used from May 2013 to May 2019. By the time of writing this thesis, the plan was already expired. Moreover, a new comprehensive plan is expected to be ready in 2020 (Matichon, 2019). In the meantime, Town Planning Act (4th Edition) was published in 2015 by the National Council for Peace and Order (a military junta which was ruling Thailand from 2014 Thai coup d ‘état on 22 May 2014 and 10 July 2019). This act is a modification for the former Town Planning Act 1975 to extend the current comprehensive plan for Bangkok until there is a new one. Moreover, there were minor adjustments on the definition parts regarding the committees of town planning. Under the military government, the significant change in the act is that the Ministry of Defence can be the committee in the planning under the condition that the town planning will cover the area which is associated with “military security”. Nevertheless, after the expired date was extended, Bangkok Comprehensive Plan 2556 has been enforced until the present.

Bangkok’s City Planning Timeline:

1952 Town and Country Planning Act 2495 BE

1957 Started to develop Greater Bangkok Plan 2533 BE 1959 Started to draft the Town Planning Act 2518 BE (1975) 1960 Litchfield Plan (draft)

1971 Greater Bangkok Plan 2533 BE 1975 Town Planning Act 2518 BE (1975)

1982 1st_{Revision of Town Planning Act 2518 BE (an organic law)}

1992 2nd_{Revision of Town Planning Act 2518 BE (an organic law)}

1992 Bangkok Comprehensive Plan 2535 BE under the Ministerial Regulation 116 1999 Bangkok Comprehensive Plan 2542 (1st Revision)

2006 Bangkok Comprehensive Plan 2549 (2nd Revision) 2013 Bangkok Comprehensive Plan 2549 (3rd Revision)

Biotope Area Factor (BAF): an index that represents the ratio of the ecologically effective area (i.e., area

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1.5 Conclusion

In conclusion, green spaces are defined here as the environmental-friendly surface covered by vegetation, open spaces, agricultural areas (defined by Bangkok’s comprehensive plan), street trees, and landscapes. Green spaces also play important roles in society, which are environmental benefits, economic and aesthetic benefits, and social and psychological benefits. Th the review of the literature on the change of green spaces in urbanised areas shows that the level of built-up area and the rising of a population affects on green spaces change. Next, the evolution of city planning in Bangkok was explained to create an understanding of city planning’s nature in Bangkok. Town and Country Planning Act 1952 was the first of city planning law in Thailand. Later in 1975, the act was replaced by the Town Planning Act 2518 BE (1975) to be compatible with the first comprehensive plan. As a result, Bangkok successfully published Greater Bangkok Plan 2533 BE in 1971. However, the Town Planning Act 1975 was problematic and outdated to support the rapid growth of Bangkok’s population, Bangkok Comprehensive Plan 2535 BE under the Ministerial Regulation 116 in 1992 to help with the mentioned issue. Since then, Bangkok’s comprehensive plan regularly has been updated every six to seven years to support the continuous increase of built-up area and population. Until now, Bangkok Comprehensive Plan 2013 is the current comprehensive plan. This current version has been improved not only to support the increase of built-up areas and population but also to supports the expansion of green spaces by providing the Biotope Area Factor rule towards the land use to maintain and expand green spaces in Bangkok.

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Chapter II: Evolution of Green Spaces

This chapter presents an analysis of the development of green spaces based on satellite images, which is the second step after examining literature about definitions of green spaces, as well as their changing nature and roles in the urban context of twentieth-century Bangkok. First, this chapter explains the sources and datasets used for the empirical analysis. Second, this chapter describes the method of satellite image analysis by using ArcGIS. Finally, the results of green spaces analysis for the period from from 1988 to 2018 in Bangkok are presented and explained.

2.1 Case Studies

Bangkok is located on the alluvial plains of the Chao Phraya River in central Thailand. Its current size is approximately 1,569 km² in 2017 (City Planning Department, 2017). Bangkok is not only the capital city of Thailand, but also the centre of the nation’s financial and economic activities, transportation, and education. The local administration is divided into 50 districts. Furthermore, Bangkok has developed the surrounding metropolitan area, which is part of five provinces (Samut Prakarn, Samut Songkram, Samut Sakorn, Nakhon Pathom, and Nonthaburi). The combination of the metropolis and its metropolitan surroundings cover an area of in total 7,758 km².

Map 1: Map showing Bangkok and Bangkok metropolitan areas

The city is a large metropolis area; thus, the study area should be brought back to smaller areas. The research questions focus on the development of green spaces and built-up areas, and city planning in Bangkok. Thus, the chosen methodological approach requires at least two study areas, so that they can be compared in terms of the level of built-up area and city planning. It is beyond the scope of this research to study and compare every district of Bangkok because of its sheer size. Hence, three study areas have been chosen on the basis of their level of urban

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development: a higher and a lower level of urban development. The following case studies have been chosen: 1) Sathorn District, the modern inner district of the city with high population density and urban density, and 2) Bang Na District, the suburb district of Bangkok with lower population density and urban density (see Map 2). The level of urban density of each district was considered by the land use policy of Bangkok in 1993. Sathorn district is located in central Bangkok and mostly consists of residential areas with high population and building densities, while Bang Na is a suburb and consists of residential areas of low to medium levels of density.

Map 2: Sathorn (in green), Bang Na (in pink) and Pathum Wan (in blue) in Bangkok’s Comprehensive Plan 2535 (1992)

The building density in Sathorn is very high as it consists of many skyscrapers and condominiums, meaning that land and housing prices are high too. According to the Treasury Department (2019), the area of one square meter in Sathorn can be worth up to 187,500 Baht (around 5,668 euros/33.08 THB = 1 EUR). On the other hand, Bang Na mostly consists of housing development and is less densely built than Sathorn. Therefore, lands in Bang Na does not come with high demand such as in Sathorn and they are worth only up to 53,500 Baht per square meter (1,587 euros/33.08 THB = 1 EUR) in the real estate market.

Sathorn and Bang Na are not only fundamentally different due to their building density; they also differ in terms of population density. The population density in Sathorn in 2017 was 8,537.85 inhabitants/km2, while Bang Na is almost twice less populated with 4,835.38 inhabitants/km.2 The differences in population density and building density of Sathorn and Bang Na allow a comparative analysis of changes in green spaces in Bangkok.

However, both districts are predominantly residential areas where developments may have differed from those in non-residential districts. In order to compare the evolution of green space in residential and non-residential areas, 3) Pathum Wan district, the commercial area of Bangkok, will also be analysed. Pathum Wan is well known as the prime commercial space of Bangkok, as it is the location of many famous department stores such as Siam Paragon, Central

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World, Siam Square One, Siam Discovery, and others. According to Bangkok’s Comprehensive Plan in 1992, Pathum Wan mostly consists of green spaces, educational institutions, government offices and commercial area. Nevertheless, the numbers in Table 1 show that the population density in Pathum Wan was slightly higher than in Sathorn and significantly higher than in Bang Na.

Map 3: Sathorn (in green) and Bang Na (in pink), and Pathum Wan (in blue) in Bangkok’s land use policy (1992)

In 2002, around 700 square kilometres of Bangkok were urbanised area. In addition, the major land uses in Bangkok are 1) residential area (23.36%) 2) agricultural area (23.53%), open space (24%), and other land uses such as commercial area and industrial area (29.1%) (Bangkok Metropolitan Administration, 2002). Sathorn, Bang Na, and Pathum Wan are the study areas of this research and representative for other areas in Bangkok. Their general characteristics are presented in Table 1.

Table 1: General Information of Sathorn, Bang Na, and Pathum Wan (2018)

Sathorn Bang Na Pathum Wan Bangkok

Size 9.326 km2 _{18.789 km}2 _{8.37 km}2 _{1,568.737 km} 2 Population 79,624 90,852 49,121 5,569,644 Population Density 8,537.85/km2 _4,835.38/km2 _5,868.69/km2 _3,550.40/km2 District Established 9 November 1989 6 March 1998 1914

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-2.2 Sources and Datasets

For the analysis of the evolution of green space in Sathorn, Bang Na and Pathum Wan several sources and datasets can be used. For the analysis of the evolution of green spaces the the satellite images from Landsat and the Bangkok censuses proved to be important sources, which have to be briefly introduced.

The images that have been used for the analysis of green spaces are Landsat satellite images from 1988 to 2018. The images are a part of the Landsat Program, a series of earth’s observing satellite missions to observe and obtain satellite imagery of the earth. The program started in 1972 and jointly managed by The National Aeronautics and Space Administration (NASA) and the United States Geological Survey (USGS). The advantage of using Landsat satellite images is that the images are clear, reliable and approachable to all the researchers, as well as compatible with ArcGIS tools for image analysis. Satellite images from the Landsat Program are open data and can be retrieved by using the USGS Global Visualisation Viewer (GloVis) . The Landsat 6 program obtained satellite images of Bangkok from 1988 to 2018, which were retrieved by the satellites Landsat 4-5 ™ C1 Level-1 and Landsat 7 ETM+ C1 Level-1.

The selection of satellite images for the three case studies is based on the following criteria: 1) the availability of data, since not all Landsat satellites captured all images in the same year; and 2) the quality of the photograph, as it should not be covered by clouds. The land cloud cover value was set at the 0-10% (the less the clearer), and the selected images were taken in the daytime. The selected images are subsequently imported as GeoTIFF files. 7

The second important dataset used for analysing the evolution of green space in the selected districts is Thailand’s administrative boundaries GIS shapefiles , which are provided by the 8 Royal Thai Survey Department. They were created on August 17, 2017, yet the latest updated version (March 1, 2019) has been used. The administrative boundaries shapefiles contain four levels of boundaries, which are level 0 (country), level 1 (province), level 2 (district), and level 3 (sub-district). However, Bangkok’s administrative boundaries were modified in 1997, and 1998, when were several new districts were created, including Bang Na district. Bang Na district was a sub-district of Phra Khanong district until its separation in 1998. Thus, in the analysis of Bang Na district in 1988-1998 is considered at the sub-district level (Bang Na sub-district).

USGS Global Visualisation Viewer (GloVis): https://glovis.usgs.gov .

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GeoTIFF allows georeferencing information to be embedded within a TIFF file (a computer file format for

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storing raster graphics images). TIFF data format is widely accepted adaptable raster data format

(Mahammad & Ramakrishnan, 2009). The TIFF imagery file format can be used to store and transfer digital satellite imagery, scanned aerial photos, elevation models, and scanned maps. However, working with GIS somehow needs the geographic information such as coordinate systems, ellipsoids, datums, or map projections within TIFF imaginary file for image positioning images on the correct location and geometry.

Shapefile is a type of computer file established by Esri, an international supplier of geographic information system 8

software, web GIS and geodatabase management applications. Shapefile is vector data storage format for storing the location, shape, and attributes of geographic features. It is stored as a set of related files and contains one feature class

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Together, these datasets enable an exploration of green spaces and built-up areas in Bangkok from 1988 to 2018. Sathorn, Bang Na, and Pathum Wan are Bangkok’s representative area’s, as an highly urbanised area, a suburb area, and a commercial area. The satellite images are analysed to establish the size of green spaces and other forms of land use.

2.3 The Evolution of Green Space

In order to answer the question as to how green space evolved in the three selected districts in Bangkok, the changes in the size of green space will be examined by analysing the series of satellite images from 1988 to 2018. Satellite images of Bangkok area taken by Landsat from this period are manipulated to calculate the size of green space in relation to built-up areas and undeveloped areas. The analysis of the three case studies, Sathorn, Bang Na and Pathum Wan, is conducted with ArcMap and shows the evolution of each type of land use.

Initially, Landsat’s satellite images of Bangkok from the year 1988 to2018 were retrieved by using the USGS Global Visualization Viewer (GloVis). Each Landsat satellite has (been) in orbit to capture the images in different period of time. The satellites that captured the images of Bangkok from 1988-2018 are Landsat-4 (1982-1993), Landsat-5 (1984-2013), and Landsat-7 (1999 to present). Since the launch of Landsat-4 (1982), Landsat satellites provided a thematic mapper (TM), which it collects seven spectral bands instead of three (such as in the previous Landsat-1–3 satellites). The multispectral images consist of green, red, blue, mid-infrared and near-infrared bands that have a resolution of 30 meters. However, the Enhanced Thematic Mapper (ETM+) attached to the upgraded Landsat-7 has added a panchromatic band, which spans the entire visible spectrum. The new upgrade on Landsat-7 results in images with 15 meters resolution pixels. According to the availability of the data, the analysis could only provide the data that is later than 1987, which was the year that Landsat started to capture the image of Bangkok continuously. Hence, each image was chosen under the criteria of image quality, as explained, to prevent cloud blocking of the study areas. Finally, the satellite images of Bangkok from 1988-2018 were retrieved as GeoTIFF files.

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Map 4: GeoTIFF file containing parts of Thailand on the world map (grey)

The importance of the satellite images is that they allow to determine changes in green space and other areas over time. To measure the size of these areas, the maximum likelihood supervised classification has been used. This classification tool works within ArcMap. The maximum likelihood supervised classification assigns each cell of a satellite image to one of the classes in the signature file. The tool requires samples to process the analysis. The samples can be acquired by manually selecting coloured pixels in the image which they will be later stored and categorised as classes. In this process, four classes were created, which are green spaces, built-up area, water area, and undeveloped area. The samples were carefully chosen for each class. After the samples were given to each class, the tool computes the probability for each class to determine the membership of the cells to the class.

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The image above is an example of Sathorn district in 2010. The Training Sample Manager tool stores the samples as classes before using the Maximum Likelihood Classification. Class

Name attribute represents a type of land use, Value attribute represents the order of sample’s

value chronologically by the selecting time. Color attribute represents the colour of each class. And, Count attribute represents the counted areas of each class.

The accuracy of the classification needs to be further explained. When performing the maximum likelihood classification, an output confidence raster is created at the same time. The classification confidence has 14 levels. The first level of confidence is confidence raster 1, which consists of the cells that are nearest locating to the selected sample cells. Thus, confidence raster 1 has the highest reliability. In addition, the level of confidence represents the level of certainty: the higher the level, the lower the certainty. Therefore, sample taking should be cautiously performed to avoid inaccuracy which can be caused by wrong selecting of samples for certain land use. The following figure represents the accuracy of the tool.

Map 5: The raster showing the classified area of Sathorn (2010) in comparison with the original raster green, yellow, blue, and grey are representing green spaces, built-up area, water, and undeveloped area respectively

The maximum likelihood classification generated the raster of the calculated area of each four classes: green spaces, built-up area, water, and undeveloped area. The tool can compute one raster at a time. In addition, the maximum likelihood classification will calculate the whole raster. Hence, I clipped each district from a raster of a satellite image into three rasters of Sathorn, Bang Na, and Pathum Wan to maintain them as separated districts. The clipping can be done by using the Clip tool and a feature class of each district as a template to maintain its original geo-referencing. One satellite image refers to one year. As a result, each study area consists of 30 rasters for each year (1988-2018).

In addition to this visualisation, it is necessary to calculate the size of each type of land uses. The Zonal Geometry as Table tool in ArcGIS is used to convert the raster into a value table. The tool will compute the size of values in a raster by considering all areas of input (raster or feature) that hold the same value as a zone. Each value counts as a zone (refers to Rowid in Table 3), which each zone refer to one particular type of land use. To clarify, the size of yellow (built-up area), green (green spaces), blue (water), and grey (undeveloped areas) areas in Map 5 will be

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presented in a table (Table 3). Each study area of each year will be computed by the tool separately because the tool can handle only one raster at a time. The zone’s size has been obtained from the existing raster dataset, which has been derived from metadata embedded within GeoTIFF file. The Zonal Geometry as Table tool calculates the area of each zone per district (Table 3).

Table 3: The output table represents the result from using Zonal Geometry as Table tool in Sathorn area in 2010

The tool was used to create output tables for each district in each year. For example, Table 3 shows the geometric information from each land uses (zone) in Sathorn district in 2010. This process produced 90 output tables of each land-use size in Sathorn, Bang Na, and Pathum Wan from 1988 to 2018.

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Rowid and VALUE attributes: is the class of each zone (which are green space, built-up area,

water, and undeveloped area)

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Area attribute: is the size of each zone (m2₎

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PERIMETER: is the boundary line of zone

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THICKNESS: is the deepest point within the zone from its surrounding cells

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XCENTROID: locates the centroids of each zone in x-axis

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YCENTROID: locates the centroids of each zone use in y-axis

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MAJORAXIS: the length of the major axis, which is measured in map units

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MINORAXIS: the length of the minor axis, which is measured in map units

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ORIENTATION: is defined as an angle between the x-axis and the major axis of the ellipse.

The values are in degrees, with a possible range of 0 to 180.

These geometric components of an output table as a result after using The Zonal Geometry as Table tool can be further explained in ArcGIS’s tool reference page. Finally, the size of each land use (values from Area attribute) are manually annotated into one table and stored as .csv file to create new datasets. The dataset consists of District, Year, Landuse, Value, and Ratio columns which can be accessed here. Lastly, the new datasets were used to generate statistical data

visualisations of green spaces and built-up areas by using Seaborn . 9

Rowid VALU E AREA PERIM ETER THICK NESS XCEN TROID YCEN TROID MAJO RAXIS MINO RAXIS ORIEN TATIO Green Space 1 914400 54300 93.63 665845 .7 1516826 847.70 68 343.35 29 12.846 64 Built-up 2 4777200 134940 201.21 66540. 2 1516572 1788.8 93 850.03 97 19.325 89 Water 3 1222200 109620 51.21 665575 .8 1516740 980.85 52 396.63 18 12.316 11 Undevel oped 32 320400 32820 45 665897 .9 1516632 451.57 54 225.84 59 12.119 92

Seaborn is a Python data visualization library based on matplotlib. It provides a high-level interface for

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Evolution of Green Space

RIJKSUNIVERSITEIT GRONINGEN

Evolution of Green Space

The analysis of Green Space Change and its Driving Forces

in Bangkok, Thailand

Contents

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Introduction

Chapter I: Definitions and Literature Review

1.1 Defining Green Spaces

1.2 The Role of Green Space

1.3 The Study of Changing in Green Spaces in Relation to

Urbanisation and City Planning

1.4 Bangkok’s Urban Planning Evolution

1.5 Conclusion

Chapter II: Evolution of Green Spaces

2.1 Case Studies

-2.2 Sources and Datasets

2.3 The Evolution of Green Space

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