LIMITED DEVELOPMENT IN THE SHENZHEN BAY AREA A FUTURE MODEL FOR COORDINATED DEVELOPMENT OF URBANISATION AND ECOCONSERVATION

Xing Jiao Jeroen van Ameijde

Introduction

The population concentration and the expansion of built-up areas caused by urbanization greatly affects the function of ecosystems (Wenjing et al., 2020) and has impacted ecological corridors (Deng et al., 2017), bird migration paths, natural habitats (Paker et al., 2014), vegetation cover (González-García et al., 2014), photochemical pollution and noise pollution (Kempenaers et al., 2014). The goal of sustainable urban development is to achieve a balance among environmental, economic and social sustainability (Mensah, 2018). This will make the city greener, fairer, and profitable for all the stakeholders (Figure 1). The key conceptual principles of sustainable urbanism include: Core values (Stevens et al., 2010): compactness (density) and biophilia (human access to nature);

Core factors (Schwartz, 2013): urban transportation, energy efficient built environment, carbon measurement and planning, air quality, green energy, sustainable communities, adaptation and resilience, waste management, intelligent city infrastructure, finance and economic development;

As the coastal zone of the Greater Bay Area consists of spaces where water and land meet and interact, it is also a zone where urban areas coexist with natural elements, marine life and terrestrial vegetation and species. As any new urban developments in these areas is adapted to topography, water bodies and shorelines, the urban and natural environment are impacted by new flows of people and resources. It is crucial to consider the balance between urbanisation and ecology, and the impact on local climate, human and ecological health, and sustainable development goals for the urban communities.

Different models have informed the general rubric of sustainability. The Compact City focuses on sustainable development, urban transportation, urban density and quality of life (Gang et al., 2008), but it’s environmental benefits are disputed (Breheny, 1997). The Eco-city model takes the environmental aspects of sustainability as its primary goal while neglecting the economic effect (Hodson & Marvin, 2010). The Blue Urbanism concept proposes the sustainable development of cities and oceans, how- ever, there are still few practical examples of this approach, and the theoretical basis is not fully developed (Beatley, 2014). As the reality of urban development is a complex process involving many parameters and stakeholders, Therefore, extracting positive benefit elements from a single model and using it to synthesize a comprehensive model can achieve the goal of sustainable development in an all-round way and achieve the balanced development of urbanization and ecology.

The goal of this article is to propose a new comprehensive model that balances between urbanization and ecology, and test how it applies to the Shenzhen Bay area. The new model could serve as a reference for other development locations, and promote the sustainable development of the many coastal cities in the Greater Bay Area. The paper reviews the existing theories found within related literature, and discusses the rationality of the theories and their arguments. It then analyses case studies that demonstrate and put forward several strategies for sustainable urban development. Based on these findings, a comprehensive model is formulated and tested on the case study site, to explore its applicability and validity.

Theories And Methods

Compact city

The ‘compact city’ was first proposed in 1973, with its capacity to achieve more efficiency, space, convenience and accessibility (Dantzig, 1973). The compact city is characterized by high density, and a “pleasant scale and complex functions” (European Commission, 1990). The typical characteristics of this urban model are: promoting urban renewal, preserving farmland, using mixed-use land layout, prioritizing public transportation, and promoting concentrated development of urban nodes (Breheny, 1997). It proposes the formation of urban forms using the principle of “decentralized centralization”, relying on good connectivity between urban nodes through transportation and communication technologies (Thomas & Cousins, 1996). In recent decades, the focus of the compact city has shifted from “proximity” to “accessibility” (Zonneveld, 2005). The five spatial principles, related to urban planning include: high density, urban centres at different levels, curbing urban sprawl, reducing the use of car traffic, improving the use of green space and open space and connecting the urban region by public transport (Kiyonobu, 2011). The impact on lowering emissions and conservation of the countryside are the reasons why the compact city model has been advocated as sustainable (Westerink et al., 2013), and it has been proposed that the sustainability of cities in developing countries can be measured by evaluating their density, landuse mix, transportation networks, accessibility, and shape dimensions (Kotharkar et al., 2014).

The compact city model is considered to be an effective solution to improve urban efficiencies when a city prepares strategic planning and urban design policies (Bibri, 2020). Otherwise, the model may produce adverse effects such as the exposure to pollution by a concentrated population, which affects health (Neuman, 2005). It may also lead to increased housing prices, traffic congestion and social exclusion (Bramley & Power, 2009), increased crime rates (Burton, 2001), an increased income gap and a lack of green space accessibility (Burton, 2001). High-density is associated with crowding, leading to reduced amounts of public open space and urban green space per person (Breheny, 1996). The main arguments around the compact city model focus on the environmental benefits, but the social and community sustainability aspects need to be further researched.

Sweden is one of the countries with the highest levels of sustainable development practices (Dryzek, 2005, p. 166). Both Gothenburg and Helsingborg deploy the compact city model towards their urban planning practices and strategies to achieve sustainable development (Bibri et al., 2020). Table 2 gives an overview of their various detailed planning strategies towards a sustainable compact city, organised according to the categories of Compactness, Density, Mixed Land Use, Sustainable Transportation and Green Structure.

From analysing these case studies, we can

Gothenburg (Bibri et al., 2020)

Helsingborg (Bibri et al., 2020)

Stockholm (Bibri & Krogstie, 2020b)

Malmö (Bibri & Krogsti e, 2020b)

Shenzhen (Zhou & Karlskro na, 2010)

447.8 346 5400 159 1997.80 1110.78

Hong Kong (Lau et al., 2008) Land area (km²)

Population 599,000 135,300 806,000 344,100 17,560,0 00 7,500,70 0

Average age 39 40 39.8 37.9 34 85

Issues Urban sprawl; High immigration; Density of built areas

Urban sprawl; Density of built areas

Urban sprawl; Restore brownfield areas; Traffic congestion;

Policies Compact city comprehensive planning

Loss of green space; Restore brownfield areas; Traffic congestion

Lack of land resource; Unbalanced development; Car-orien ted situation;

Compact city eco-city

Loss of green space; Urban development; Traffic congestion

Eco-city; Eco-city Compact city Vertical city Compact city Sky city

Table 1. Figures of the precedent cities, summarised from (Bibri et al., 2020; Bibri & Krogstie, 2020b; Lau et al,, 2008)

Table 2. Strategies from precedent cities to achieve sustainability goals, summarised from (Bibri et al., 2020; Bibri & Krogstie, 2020b; Beatley, 2014) summarise some key aspects of the compact city principles, which include nearness, connectedness and accumulation (Bibri et al., 2020). The Comprehensive Plan for Gothenburg and The Master Plan for Helsingborg focus on three aspects of spatial planning to implement compactness (Helsingborg,

2010a; Gothenburg City Council, 2014a): For the central area and the surrounding renewal areas: a combination of concentrated and high-density developments of commercial functions, providing intensive employment and family housing. Concentrating on strategic nodes, at the

Design principles

Strategies for environmental, economic, and social sustainability

Compact City strategies : Gothenburg and Helsingborg (Bibri et al., 2020)

Compactness l Build and develop centrally l Concentrate on strategic nodes l Complement and mix l Reserve outer city areas for future development

Density l High density of built objects in designed and emergent compact urban form l Diverse scales of built objects l Distribution of building footprints with frequent larger buildings l Greater density in strategic nodes l Prioritization of density close to the central points of strategic nodes l High density combined with multidimensional mixed land use

Mixed Land Use l Physical land use mix (business activity, production, consumption, etc.) l Social mix (housing, demography, lifestyles, etc.) l Greater mix of housing, business, and facilities in strategic nodes l Multidimensional mixed land use combined with sustainable transportation

Sustainable Transportation l Cycling and walking l Public transport (metro, buses, tram, etc.) l To improve mobility management infrastructure l Cooperate with sustainable transportation, multidimensional mixed land use and high density l Network structure of link areas to connect the major nodes of the transport system

5 of 22 l Separate lanes for the public transport l time and a punctual and reliable system

Design principles

Green Structure

Compactness

Strategies for environmental, economic, and social sustainability l More services along the main corridors l An easy to understand, safe, and secure system for guaranteeing quality and service

Compact City strategies : Gothenburg and Helsingborg (Bibri et al., 2020) l Multi-model travelling in strategic nodes to support their dense, mixed use central points

Intensification

Density l Green areas and parks l Build and develop centrally l Green areas hand in hand with density l Concentrate on strategic nodes l Complement and mix l Reserve outer city areas for future development l Protection and integration of natural, agricultural, and cultural areas through intensification l Increase in population l Increase in redevelopment of previously developed l High density of built objects in designed and emergent compact urban form l Diverse scales of built objects