地理学报 ›› 1998, Vol. 65 ›› Issue (1): 87-96.doi: 10.11821/xb199801011

• 论文 • 上一篇    

长江水系沉积物重金属含量空间分布特征研究——空间自相关与分形方法

张朝生1, 章申2, 何建邦1   

  1. 1. 中国科学院地理研究所资源与环境信息系统国家重点实验室,北京100101;
    2. 中国科学院地理研究所化学地理室,北京100101
  • 收稿日期:1996-05-01 修回日期:1996-10-01 出版日期:1998-01-15 发布日期:1998-01-15

SPATIAL DISTRIBUTION CHARACTERISTICS OF HEAVY METALS IN THE SEDIMENTS OF CHANGJIANG RIVER SYSTEM ——SPATIAL AUTOCORRELATION AND FRACTAL METHODS

Zhang Chaosheng1, Zhang Shen2, He Jianbang 1   

  1. LREIS, Institute of Geography, Chinese Academy of Scienes, Beijing 100101
  • Received:1996-05-01 Revised:1996-10-01 Online:1998-01-15 Published:1998-01-15

摘要: 所研究的11种重金属元素在长江水系沉积物中均有较显着的空间自相关性;沉积物细粒中重金属含量空间自相关性好于沉积物原样;正相关尺度达500km左右,与空间分布斑块大小对应;研究区沉积物重金属含量空间分布分形存在于约1000km以内,分维数处于2.76~2.95之间,分维数的大小与空间自相关指标大小在各元素间的变化趋势相反,表明这两种指标具有一致性;多数元素在NW-SE向和NE-SW向相关性较好,与变异函数所揭示的方向性特征一致。

关键词: 空间自相关, 空间相关图, 空间分布, 分形, 沉积物, 重金属

Abstract: The spatial distribution characteristics of 11 heavy metals (Cu, Pb, Zn, Cd, Hg, Co, Ni, As, Cr, Mn and Fe) in the sediments of the Changjiang River system were studied with methods of spatial autocorrelation and fractal. Moran’s I indices were calculated to quantitatively describe the significance and the directional characteristics of their spatial autocorrelations, and spatial correlograms were drawn to show the variation of spatial autocorrelation along with the changes of distance. Fractal dimensions were calculated to reveal the complication degrees of the spatial distributions. Significant spatial autocorrelations are detected for all of the elements studied. The spatial autocorrelations of heavy metals in fine grained sediments are better than those in raw sediments. The positive autocorrelations extend to about 500 km, which is consistent with the sizes of patches in the distribution maps. Fractals exist in about less than 1 000 km , and fractal dimensions are around 2.76~2.95. The variation of fractal dimension among elements has negative trend against Moran’s I, which shows consistence of the two indices. Most of the elements have relatively good autocorrelations in the directions of NE SW or NW SE, which are consistent with the results from variogram method.

Key words: spatial autocorrelation, spatial correlogram, spatial distribution, fractal, sediments, heavy metals

中图分类号: 

  • P736.211