Spatial-Temporal Evolution of Main Cargo Structure in the Port System of Yangtze River Delta
以长三角19个主要港口为对象，用赫芬达尔指数和探索性空间数据分析2004-2012年煤炭、石油、集装箱吞吐量的集中度和空间演变特征，发现煤炭从分散趋向集聚但效果不显著，石油空间相关性增强，集装箱无明显集聚或分散。
Taking the 19 major ports in the Yangtze River Delta(YRD) as the research object, the 2004- 2012 concentration trend of main cargo throughput is analyzed by using Hirschman- Herfindahl Index(HHI). And the spatial evolution characteristics of main cargo throughput are studied by using Exploratory Spatial Data Analysis. The results show that the concentration degree of coal, petroleum and container has a downward tendency from 2004 to 2012. The coal throughput structure has an evolution trend from spatial dispersion to spatial agglomeration, but the spatial agglomeration effect is not obvious. The petroleum throughput structure has a trend of increased spatial correlation. The container throughput structure does not have an obvious spatial dispersion or spatial agglomeration effect.