Acta Geographica Sinica ›› 2012, Vol. 67 ›› Issue (1): 27-35.doi: 10.11821/xb201201003

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The Priority Pattern for Managing the Potential Ecological Risks Associated with Heavy Metals of the Top Soil on Yancheng Coast

FANG Shubo1,2, JIA Xiaobo3, AN Shuqing4, ZHENG Zheng1   

  1. 1. Environmental Science and Engineering Department, Fudan University, Shanghai 200433, China;
    2. College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China;
    3. Laboratory of Riverine Ecological Conservation and Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China;
    4. The Institute of Wetland Ecology, School of Life Science, Nanjing University, Nanjing 210093, China
  • Received:2011-08-11 Revised:2011-10-08 Online:2012-01-20 Published:2012-01-20
  • Supported by:
    National Natural Science Foundation of China, No.41101172

Abstract: The spatial geostatistical characteristics of the 5 heavy metals (Cr, Cu, Ni, Zn and Cd) of the top 106 soil samples on Yancheng coast, were studied with the aid of GS+ software. With ARCGIS 9.2, the Hakanson risks index (HRI), which was a synthetic reflection of the potential ecological risks of heavy metals, was interpolated. A computational approach, including NDVI, determining Euclidean Distance to the main anthropogenic impact sources, and land use reclassification, was proposed to detect the ecological hotspots, with clarification of different levels of potential ecological risks through integrating the Hakanson index computing. The conclusions can be drawn as follows. Metals (Cr, Cu and Cd) had strong spatial autocorrelations, while Ni had modest spatial autocorrelations, and the spatial autocorrelation of Zn could not be modeled. Through the semivariogram functions analysis, the exponential model could best model the spatial autocorrelations of Cr and Ni, while spherical model could best model Cu and Cd. There was a high heterogeneity of HRI, and areas including the Dafeng Natural Reserve areas, near the Liangduo River Gate, the areas between Dafeng Habour and Simaoyou Gate, and areas north to the Sheyang Habour, had a relatively low HRI, while areas including areas neighboring Sheyang Habour and Sheyang Salt Field had a high HRI. The priority ecological hotspots with medium and low heavy metal ecological risks were finally proposed.

Key words: heavy metals, semivariogram model, Hakanson index, ecological hotspots, priority management areas