论文部分内容阅读
The primary object of this research is to present a ecoregion model based on the principle components analysis (PCA),the cluster analysis (CA),the discriminant analysis (DA) and the spatial autocorrelation analysis(SAA),which were applied to establish the ecorigion of lake nutrients in Yunnan-Guizhou Plateau Lakes.First,the principle components analysis method was not only used to reduce the dimensionality of the feature space,but also could deal with new indexes.These complementary indexes which reflect the conditions of lakes were helpful to establish the index system of ecorigion of lake nutrients in Yunnan-Guizhou Plateau Lakes.Second,initial classification of lake drainage area was accomplished by new indicator values and cluster analysis,then the categories of nonlake drainage area could be identified by the discriminant analysis.Finally,spatial distribution pattern of the region was achieved by the quantificational analysis about over score of principle components and application of spatial autocorrelation method.Then the ecorigion of lake nutrients was accomplished by the association and difference between different districts of the scattered regions(s) spatial character.These results indicated that the ecoregion model initiated in the paper was appropriate and feasibleto receive objective results and avoid artificial factors.Also it has provided a new method to explore the index system and techniques about the ecoregion of lake nutrients.Scientifically,the model was in favor of the foundation of lake nutrient criteria and eutrophication control standards in china.