Spatial-Temporal Gradient Analysis of Urban Green Spaces in Jinan, China Fanhua Kong ∗, Nobukazu Nakagoshi
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Landscape and Urban Planning 78 (2006) 147–164 Spatial-temporal gradient analysis of urban green spaces in Jinan, China Fanhua Kong ∗, Nobukazu Nakagoshi Graduate School for International Development and Cooperation, Hiroshima University, Kagamiyama 1-5-1, Higashi-Hiroshima 739-8529, Japan Received 24 November 2004; received in revised form 27 June 2005; accepted 5 July 2005 Available online 23 September 2005 Abstract In China, rapid urbanization has profoundly transformed the spatial pattern of urban land use, including urban green spaces. The government plans to optimize green spaces to integrate with urban development; this requires an understanding of the process of green space change. Quantification of green space patterns is a prerequisite to understanding green space changes, and is essential for monitoring and assessing green space functions. This paper presents a new method for quantifying and capturing changes in green space patterns, through a case study of Jinan City, China, during 1989–2004. Supported by GIS and remote sensing, the method comprises quantification of local area green spaces by the “moving window” technique (using FRAGSTATS), and a gradient analysis involving sampling from the urban center to the fringe. Results demonstrate that the significantly altered green space pattern could be quantified using landscape metrics in each local area. Gradient analysis undertaken in eight directions from the urban center reflects the changes in and effects of urbanization, and the implementation of government policy. In comparison with quantifying metrics in entire landscapes, this method more effectively links patterns and processes, and can establish an important basis for subsequent analysis of ecological and socioeconomic functions of green spaces. © 2005 Elsevier B.V. All rights reserved. Keywords: Gradient analysis; Landscape metrics; Moving window; Remote sensing; Urban green spaces 1. Introduction but this increased to one in three by 1980 (World Com- mission on Environment and Development, 1987). It As a result of urbanization, the world’s popula- is expected that about 65% of the world’s population tion has become increasingly concentrated in cities. In will live in urban areas by 2025 (Schell and Ulijaszek, 1940, only one in eight people lived in an urban center, 1999). Population increases triggered the rapid growth of urban centers, and the environmental and socioeco- ∗ nomic consequences of this growth are profound; the Corresponding author. Tel.: +81 90 7508 8072; fax: +81 824 24 6987. increasing alienation between humankind and the nat- E-mail address: [email protected] (F. Kong). ural world is a particularly fundamental consequence 0169-2046/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.landurbplan.2005.07.006 148 F. Kong, N. Nakagoshi / Landscape and Urban Planning 78 (2006) 147–164 of urbanization (Gordon, 1990). Urbanization has had landscape ecology also offers insights regarding the and continues to have a negative impact on green space optimization of the use of space vis-a-vis` environ- within cities. The impact of urbanization on urban mental conservation and improvement (Forman and green space is illustrated by the case of Mexico City, Godron, 1986; Dramstad et al., 1996; Jim and Chen, where the proportion of the city’s area that is made up 2003). of urban green space is falling by about 3.7% annually Landscape ecology deals fundamentally with how, (Nilsson and Randrup, 1997). when, and where spatial and temporal patterns influ- Urban green spaces can be defined as outdoor ence ecological processes, and how feedback from places with significant amounts of vegetation, and exist ecological processes influences ecological patterns mainly as semi-natural areas (Jim and Chen, 2003). (Turner, 1989; Urban et al., 1991; McGarigal and Cush- Urban green spaces are viewed as the last remnant man, 2002). Four basic elements are used to define of nature in urban areas (Beatley, 2000), and typ- landscape patterns: number, size, shape and juxtapo- ically perform important functions, including main- sition of patches; spatial patterns are quantified using taining biodiversity (Attwell, 2000), preventing soil landscape metrics. These are important contributors erosion (Binford and Buchenau, 1993), absorbing rain- to the interpretation of spatial patterns and ecological water and pollutants (Groot, 1994; Conine et al., 2004), processes (Gardner et al., 1987; O’Neill et al., 1988; and mitigating urban heat island effects (Stanners and Dunn et al., 1990; Wang and Zhang, 2001). Gradi- Bourdeau, 1995; Miller, 1997). Urban green spaces ent analysis, developed in the context of vegetation can also provide considerable socioeconomic benefits, analysis (Whittaker, 1967, 1975), has been used to such as providing amenity-recreation venues, reducing investigate the effects of urbanization on plant distri- work-related stress (Kaplan and Kaplan, 1989; Gobster bution (Kowarik, 1990; Sukopp, 1998) and ecosystem and Westphal, 2004), and increasing property values properties (Pouyat and McDonnell, 1991; Pouyat et al., (Geoghegan et al., 1997; Tyrvainen,¨ 1997; Morancho, 1995; Zhu and Carreiro, 1999). In recent research, Luck 2003). Rapid urbanization and increased leisure time and Wu (2002) and Zhang et al. (2004) used gradient make people more aware of urban green space, and analysis to study urban landscape patterns and the eco- there is an increasing realization that it is difficult to live logical consequences of the urbanization process by without some contact with nature. Even though they using a “split window” along their chosen transect. It become more urban in their way of life, the desire for remains difficult, however, to obtain spatial information contact with nature will continually increase rather than on each local area for the entire landscape. The prob- decrease (Miller, 1997). At the same time, governments lem of how to link pattern and process accurately in any are beginning to recognize the importance of healing local area has yet to be solved. In this study, instead of the rift between humans and nature. Green space is analyzing the whole or partial landscape pattern, gradi- becoming an important measure in judging the eco- ent analysis, supported by the “moving window” option logical sustainability of urban areas (Chiesura, 2004). in the FRAGSTATS program (Version 3.3) (McGarigal Planners and designers need efficient tools to quantita- et al., 2002a), was used to quantify the local landscape tively evaluate and compare the impact of alternative pattern across space (McGarigal and Cushman, 2002). plans and designs so that more informed development Quantified landscape metrics, combined with gradient choices could be made. analysis, were judged to be the most appropriate way The theory of landscape ecology has spawned sig- of relating the spatial pattern of urban green spaces to nificant innovation in landscape planning and design urbanization and underlying human processes, and of (Nassauer, 1999). The surge of interest in landscape determining their influence on ecological attributes of ecology is discernable in recent efforts to incorporate the environment. a landscape perspective into policies and guidelines Jinan City, a medium-sized provincial capital city for managing public lands (McGarigal and Cushman, representative of metropolitan areas in China, was cho- 2002). Landscape ecology is particularly well suited to sen as the study area. Since the Reform and Open Policy studying urban green spaces because both man-made and the Urban Land Reform were initiated in the 1980s, and remnant natural areas are considered (Design Cen- Chinese cities have been facing rapid urban expansion ter for American Urban Landscape, design brief, 2003); and development (Cheng and Masser, 2003). China’s F. Kong, N. Nakagoshi / Landscape and Urban Planning 78 (2006) 147–164 149 urban population in 2001 was 37.7% of the total popu- (Fig. 1). Jinan has a typical warm-temperate, semi- lation; the urban population is projected to reach 75% of humid, continental monsoon climate and well-defined the total by 2050 (Chinese Mayor’s Association, 2002; seasons. The mean annual temperature is 14 ◦C, and Zhang et al., 2004). This rapid urbanization has pro- the average mean precipitation 650–700 mm. Jinan foundly transformed the spatial pattern of urban areas. also has a special geological structure. Underground The government is now planning green spaces that will streams from Taishan flow along the limestone strata be integrated with urban development. This process to Jinan. The streams are halted to the north by igneous began in the 1980s, and the majority of cities imple- rocks and emerge in the form of numerous springs. mented green planning in the 1990s. Since the estab- There are at least 72 famous springs, and so it is lishment of its urban master plan (covering 1996–2010) known as the “City of Springs”. The natural vegetation in 1996, especially, the “Great Changes in Five Years” is deciduous broadleaf and evergreen coniferous policy in 1997: Jinan Wu Nian Da Bian Yang Fang An, forest. Human activities and influence have resulted in which states that “the local government and the citi- most of the original natural vegetation (such as Salix zens of Jinan City should fight their way to optimize babylonica L.) being partially or completely removed. the urban spatial pattern and improve the urban envi- As a result, the landscape that was once described in ronment in a period of about 5 years (1997–2001)”,