Measuring Urban Sprawl A Case Study of China

Transcription

1 Institute for Regional Development Planning, University of Stuttgart Applying Remote Sensing and GIS on Monitoring and Measuring Urban Sprawl A Case Study of China

2 Outline Research hbackground and dobjectives Urban sprawl in perspective Research Area and Data Source Methodology of Research Results and Discussion

3 Research Background The understanding on urban sprawl in China still rest on qualitative discussion instead of quantitative analysis. There is no clear cea answer to identify sprawl and evaluate the extent tof sprawl To find good ways for analyzing the spatial features and unique mechanism of urban sprawl with Chinese context is very important

4 Research Objectives What happen? Monitoring urban sprawl in research area using remote sensing classified images and identifying the basic patterns of urban sprawl in research area. Why happen? Analysing the internal and external driver forces of urban sprawl and determining the main factors led to urban sprawl in research area. How happen? Reviewing on some methods for measurement urban sprawl and measuring the extent of urban sprawl using different dimensional indicators based on GIS in research area.

5 spreading from urban area to rural area uncontrolled or unplanned extension

6 Urban sprawl in perspectivep Across states and cities of Europe and North America there is a growing awareness of,and concern about urban sprawl. How to measure urban sprawl is becoming a hot spot of research. Some research organizations have put forward their indicators for measuring urban sprawl (Sierra Club,1998;USA Today,2001;Smart Growth American,2002;European Environment Agency,2006) Besides, many scholars focus on using indicators to measure urban sprawl by establishing i multi-dimensional i i indicatorsi by GS GIS analysis or descriptive i statistical i analysis (Nelson,1999;Kline J D, 2001; Paul M Torrens,2000; Kolankiewicz, et al., 2001; Galster et al.,2001; Ewing et al.,2002; Anthony,2004;Song et al.,2004;tsai,2005; 2005; Frenkel et al., 2005; Marjo Kasanko,2006; Scheider,A. et al.,2008; Siedentop,S. et al., 2008 )

7 Urban sprawl in perspective Until now, a lot of researches just focus on the urban expansion in China, few studies on measuring urban sprawl (Yeh and Li,2001; Jiang Fang et al.,2006;huang,2006;xi Jun Yu et al.,2007), ) In short, the research on urban sprawl in China is still in a preliminary stage, the basic characteristics of urban sprawl in China have no explicit expression, and the reveal of its internal mechanisms has been maintained in the level of empiricism

8 Research Area China Jiangning County Jiangsu Province Nanjing City

9 Research Area Urban sprawl in Europe identifying the challenge Dipl. Geogr. Stefan Feng Fina, li, Prof. Dr.-Ing. Stefan Siedentop

10 Data Source Name Spatial Resolution(m) Assess Time Remote Sensing Data TM 30m Other data Software ArcGIS 9.2 (ArcInfo) Erdas 8.7 Population data Socio-economic data

11 Landsat TM Images

12 Sub-images of research area

13 Methodology of Research Remote sensing The spatial patterns of urban sprawl over different time periods,can be monitored from remotely sensed data GIS Fundamental in analyzing land cover data,and in the calculation l of the indicators

14 Remote sensing image classification Remote sensing images Construction of Feature Space Choosing Training Area Not Satisfied Conditions Testing Training Results Satisfied Conditions MLC: Maximum Likelihood Classification i Classifying Pixel Category based on MLC Classification Results

15 Built-up area information extraction Remote Sensing Image Image Preprocessing Image Classification Built-up Area Extraction As indicator to measure urban sprawl

16 Classified images Build-up Area Water Area Other Areas

17 The patterns of urban sprawl Compact Scattere Linear Strip Polynucleated Leapfrogging development development development development development (From Galster et al., 2001)

18 The patterns of urban sprawl in research area Sprawling area in the north part is larger than that in the southern Severer sprawling areas include the marginal area near suburbs, etc Three sprawling patterns are identified: randomly expansion at urban fringe, scattered development of industrial land and leapfrog development of urban residence area. 1979

19 Impact phenomena caused by changes of surface, land use pattern and ddensity surface-related impacts impacts/outcomes (examples) Loss/Degradation of Prime Farmland Surface Characteristics Landscape Fragmentation Negative impacts on aquatic systems Contribution to urban heat island density-related impacts Land Use Pattern Urban Density Higher development costs (infrastructure) Higher travel distances pattern-related impacts Less cost-efficient public transit Automobile dependence (From the research result of S.SIEDENTOP,S.FINA) SIEDENTOP S

20 Measuring urban sprawl using different indicators Indicators of Measuring Urban Sprawl Surface Pattern Density Total area Total built-up area The area change of built-up area The shape change of built-up area Fragmentation Open space efficiency Urban density The change of urban density

21 Results and Discussion High sprawl Moderate sprawl Low sprawl

22 Results and Discussion This study demonstrated that the application of remote sensing on monitoring the urban sprawl in different periods. Timely and accurate monitoring is very important to understand the relationships and interactions between human and natural phenomena and it can promote efficiency. GIS reveals spatial patterns of urban sprawl by measuring different dimensional indicators.

23 Many thanks for your attention!