The Spatial Differentiation of the Economic Development of Counties along the Lower Yellow River
分析了2009年黄河下游109个县域经济发展的空间差异，发现西南-东北向呈U型趋势、东南-西北向呈倒U型趋势，并利用SOFM神经网络将县域经济分为五类。
The spatial differences of economic development of 109 counties along the Lower Yellow River in 2009 have been analyzed by weighted principal component analysis,trend analysis tool and Moran's I index of GIS.On the basis,the classification of level of economic development is realized by the SOFM neural network model in MATLAB 7.0.Study shows that,firstly,there are significant differences for the economic development of counties along the Lower Yellow River.In the global space,it is the U-trend in the southwest-northeast and the inverted U-trend in the southeast-northwest,and the spatial concentration of the county economy is very significant as was indicated by Moran scatter plot.Moreover,Xingyang and counties in Dongying and Jinan are economically core area,while counties in Yudong Plain and Heze,in the eastern Zhongyuan economic zone,are economically collapse area.Finally,the level of economic development of 109 counties can be divided into five categories with the principal component scores as the input of the SOFM network,which is generally in line with the circle-type spatial structure theory.At the same time,it is a prerequisite to achieve good classification results by referring the results of hierarchical clustering to determine the number of neurons in the SOFM network.