J. Geogr. Sci. 2011, 21(6): 1101-1111 DOI: 10.1007/s11442-011-0903-0 © 2011 Science Press Springer-Verlag Scale effects of the continental coastline of China SU Fenzhen1, *GAO Yi1,2,3, ZHOU Chenghu1, YANG Xiaomei1, FEI Xianyun4,5 1. LREIS, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; 2. Yantai Institute of Coastal Zone Research, CAS, Yantai 264003, Shandong, China; 3. Graduate University of Chinese Academy of Sciences, Beijing 100049, China; 4. School of Geodesy & Geomatics Engineering, Huaihai Institute of Technology, Lianyungang 222005, Jiangsu, China; 5. Jiangsu Marine Resources Development Research Institute, Lianyungang 222005, Jiangsu, China Abstract: Spatial scale is a fundamental problem in Geography. Scale effect caused by fractal characteristic of coastline becomes a common focus of coastal zone managers and researchers. In this study, based on DEM and remote sensing images, multi-scale continental coastlines of China were extracted and the fractal characteristic was analyzed. The results are shown as follows. (1) The continental coastline of China fits the fractal model, and the fractal dimension is 1.195. (2) The scale effects with fractal dimensions of coastline have significant differences according to uplift and subsidence segments along the continental coastlines of China. (3) The fractal dimension of coastline has significant spatial heterogeneity according to the coastline types. The fractal dimension of sandy coastline located in Luanhe River plain is 1.109. The dimension of muddy coastline located in northern Jiangsu Plain is 1.059, while that of rocky coastline along southeastern Fujian is 1.293. (4) The length of rocky coastline is affected by scale more than that of muddy and sandy coastline. Since coastline is the conjunction of sea, land and air surface, the study of coastline scale effect is one of the scientific bases for the researches on air-sea-land interaction in multi-scales. Keywords: scale effect; fractal dimension; coastline; uplift segment; subsidence segment; coastline type 1 Introduction Scale is a premise to understand characteristics of geo-objects and processes of geographical phenomena (Yang et al., 2009). Understanding-degree on Earth System depends on the ob- servation scale. Since coastline is the conjunction of sea, land and air interface, coastline spatial scale effect is one of the scientific bases for the research on air-sea-land interaction in multi-scales. Since various geo-objects in nature present fractal self-similarity, the building Received: 2011-03-27 Accepted: 2011-05-31 Foundation: Chinese Academy of Sciences Program, No.KZCX1-YW-12-04; National Natural Science Foundation of China, No.40571129; Natural Science Foundation of Jiangsu Province, No.BK2009627; National High Technology Research and Development Program of China (863 Program), No.2011BAH23B04 Author: Su Fenzhen (1972–), Ph.D and Professor, specialized in coastal and marine geographical information system and spatial-temporal data mining. E-mail: [email protected] *Corresponding author: Gao Yi (1982–), Ph.D, specialized in the research on applications of remote sensing and geo- graphical information system. E-mail: [email protected] www.geogsci.com springerlink.com/content/1009-637X 1102 Journal of Geographical Sciences of fractal model plays an important role in spatial recognition. Coastline has been the most traditional research topic in the fractal area. Mandelbrot published his paper “How long is the coast of Great Britain?” in Science in 1967, in which he made unique analysis on the features of coastline, elaborated the uncertainty of coastline length, and put forward con- cepts of fractal and fractal dimension. Then many scientists made further researches on fractal science and established two computation models of fractal numbers: divider method and box-counting method (Mandelbrot, 1982; Lievovich, 1989). The calculated results of different coastlines are as follows: the fractal dimension of Brit- ain coastline is 1.25, Australia 1.13, South Africa 1.02 (Mandelbrot, 1967); the number of fractal dimension of Delaware Bay coastline in US is 1.4(Philips,1986); the fractal dimen- sions of western coastline of Great Britain is 1.27 calculated by the divider method, Austra- lian southern coastline 1.13, Australian northern coastline 1.19, eastern coastline of Gulf of California 1.15 and western coastline of Gulf of California 1.19 (Carr et al., 1991); the frac- tal dimensions of coastline of western United States and coastline of eastern United States are 1.0–1.27 and 1.0–1.70 respectively (Jiang et al., 1998); when analyzing the impact of environmental changes on the erosion of Arctic coasts, Lantuit et al. (2009) calculated the fractal dimensions of different segments along the coasts and discussed the impact of scale effects on shoreline erosion and the estimation of organic carbon release; Feng et al. (1997) computed that the fractal dimension of Bohai Bay coastline is between 1.0199 and 1.1255 and studied the geological implication of coastline fractal dimension; Dai et al. (2006) re- searched on the stability and the fractal of arc-shaped coast in South China with the equilib- rium modes classified on the basis of dynamical geomorphology as well as sediment supply; Zhu et al. (2004) conducted systematical research on the spatial fractal characteristic of Ji- angsu coastline by different multi-fractal computational methods; Liu et al. (2004) analyzed the fractal dimensions of coastline by provinces; Zhang et al. (2006) analyzed the fractal dimensions of a certain island with the remote sensing images of different resolution ratios. These studies revealed the fractal characteristics of different segments along the coastline. However, the fractal differences of continental coastlines of China need to be studied in a comprehensive way while spatial variations and the reasons need further research. Mean- while, quantitative interpretations need to be given on some basic questions under the back- ground of great development of coastline in the new period. Such questions include: Impact of coastline fractal characteristics on coastline surveying; fractal influence of yardstick length on the lengths of different coastlines. Such questions constitute the essential basis for scientific management and sustainable use of coastline and its resources. Based on DEM and remote sensing images, multi-scale continental coastlines of China were extracted and the fractal characteristics of different coastline segments were analyzed in light of the distribution of geologic subsidence and uplift areas with the technology of GIS and RS; the fractal characteristics of typical coastlines with their reasons were analyzed through the comparison of sandy coastline, muddy coastline and rocky coastline. 2 Study area and data source 2.1 Study area The continental coastline of China starts from the Yalu River Mouth in Liaoning Province SU Fenzhen et al.: Scale effects of the continental coastline of China 1103 Figure 1 Distribution of DEM and continental coastlines of China and extends to Beilun Estuary in Guangxi Zhuang Autonomous Region (Figure 1). Hang- zhou Bay divides the whole coastline as northern part and southern part. In the northern part, Jiangsu Plain is close to the Yellow Sea; Jiaodong Peninsula and Liaodong Peninsula stand facing each other in north-south contrast; Liaohe River Plain and North China Plain with Liaoxi Plain surround the Bohai Sea; as a result, mountain coasts and plain coasts are inter- laced. In the southern part, hills, mesas and low mountains scattered along the coasts of Zhejiang and Fujian provinces. Thus, the coastline fits the uplifted structures in Zhejiang, Fujian and Guangdong provinces. According to the spatial distribution of uplift and subsidence along the coastline, the continental coastline of China can be divided into five segments (ECCCZTWRI, 1991; Li et al., 2002): Liaodong Peninsula uplift segment, Liaohe River Plain–North China Plain sub- sidence segment, Shandong Peninsula uplift segment, northern Jiangsu–Hangzhou Bay sub- sidence segment and eastern Zhejiang–southern Guangxi uplift segment (Figure 1). There is no unified definition for coastline yet. According to the regulations of the Peo- ple’s Republic of China, coastline is defined as the boundary between sea and land at the perennial high spring tide level (GAQS, 2000).That means the 0 m contour line is next to the coastline and they overlap on maps of small and medium scales. Therefore, coastline can be replaced by the 0 m contour line when studying the scale effects of coastline at small and medium scales. 2.2 Data source The 30-m resolution SRTM1-DEM (https://wist.echo.nasa.gov) is used as basic data (Figure 1104 Journal of Geographical Sciences 1). SRTM is the acronym of Shuttle Radar Topography Mission. From February 11 to 22, 2000, after 222 hours and 23 minutes surveying and mapping of the earth surface by INSAR, Space shuttle Endeavour got 3D radar terrain data for 80% of the earth surface between 60°N–60°S. The data volume was 12TB (Rabus, 2003). Spatial resolutions of SRTM DEM are one second radian (30×30 m) and three seconds radian (90×90 m) with the number of SRTM1 and SRTM3 respectively. Its spatial reference is WGS1984, Volumetric positioning accuracy positioning is ±20 m, and vertical accuracy is ±16 m (Reuter, 2007). Besides, we also collected 33 Landsat TM remote sensing images (http://glovis.usgs.gov/). Imaging time was around the year of 2000, same with the acquisition time of SRTM1-DEM. As a base map for the revision of coastline, Landsat TM helps to ensure the positional preci- sion of coastline. 3 Methodology 3.1 Computation model of fractal dimension Fractal geometry proposes an invariant—fractal dimension according to the variation of scales, which provides a theoretical basis for quantitative description characteristics of physical geographic objects. Basic model for solution of fractal dimension in complex curves is as follows (Mandelbrot, 1967): 1−D LMGG =× (1) where LG refers to the coastline length measured by yardstick G; M is undetermined constant; G is the length of yardstick; D is the fractal dimension of the coastline to be measured.