Wang X J, Liu R M
MOE Lab. of Earth Surface Process, College of Environmental Sciences, Peking University, Beijing, China.
Environ Monit Assess. 2005 Feb;101(1-3):167-74. doi: 10.1007/s10661-005-9154-9.
Spatial structure analysis and kriging analysis have been identified to be useful tools in illustrating the spatial patterns of variables. Taihu Lake is one of the largest fresh water lakes in China, and has suffered serious eutrophication in recent years due to the rapid economic development and growing environmental pollution in the Taihu Catchment. In this paper, spatial structural analysis, kriging interpolation and eutrophication assessment were carried out for chlorophyll a in the lake. Studies show that spherical model could be applied to fit all experimental variograms. Positive nuggets were observed for three directions except NE-SW direction. The variograms show some anisotropy with anisotropic ratio falling within 1.76. The spatial structural patterns of chlorophyll a in the lake were affected by factors such as distribution of pollution sources, water flow and wind. Two-dimensional ordinary block kriging was applied for interpolation process. An eutrophication assessment map was also made based on a water-quality evaluation standard. Results show that the content of chlorophyll a in Taihu Lake was quite high. The whole lake has suffered serious eutrophication. However, the eutrophic situation varied in space. Higher contents of chlorophyll a appeared mainly in the northern part of the lake.
空间结构分析和克里金分析已被确认为是用于阐明变量空间格局的有用工具。太湖是中国最大的淡水湖之一，近年来，由于太湖流域经济的快速发展和环境污染的加剧，太湖遭受了严重的富营养化。本文对太湖中的叶绿素a进行了空间结构分析、克里金插值和富营养化评价。研究表明，球状模型可用于拟合所有实验变差函数。除了东北-西南方向外，在其他三个方向上均观察到正基台值。变差函数表现出一定的各向异性，各向异性比在1.76以内。太湖中叶绿素a的空间结构格局受污染源分布、水流和风等因素的影响。采用二维普通块克里金法进行插值。还根据水质评价标准制作了富营养化评价图。结果表明，太湖叶绿素a含量较高，全湖已遭受严重富营养化。然而，富营养化状况在空间上存在差异，较高的叶绿素a含量主要出现在太湖北部。
