基于EMD的广州市中心性变化研究

Changing Centralities of Guangzhou City Based on EMD

以Tietz公式为基础,从经济实力、产业、就业、开放、科技、教育、金融、医疗卫生8个角度构建城市中心性评价指标体系,利用层次分析法和经验模态分解(EMD)方法对广州市中心性进行分析。结果表明:广州市综合中心性在较短时间尺度上的方差贡献率小于较长时间尺度上的方差贡献率,且较短时间尺度变化的波动较不规律,而趋势性作用则强于周期性波动作用;各子领域的中心性在较长时间尺度上的作用强于较短时间尺度,而各时间尺度对于不同领域的影响程度不同。总之,趋势性和长时间尺度的影响是主流,而短时间尺度上的周期性变化则是对趋势性和长时间尺度作用的具体微调。

Based on Tietz formula,the paper build a index system from the perspective of economy,industry,employment,opening,science and technology,education,finance and medicine,assigned by analytic hierarchy process,to calculate centralities of Guangzhou City. Then the paper use EMD to analyze the trend of them. Results are as follows： Centralities of Guangzhou are less fluctuated in shorter time level than that in longer time level,and the fluctuation in shorter time level is more irregular; while trend effect is stronger than cyclical fluctuation effect.For each field,the effect in longer time level is also stronger than effect in shorter time level,and the amount for them are various. As a result,it is concluded that the trend effect and long-time effect are the main facts for centralities,while short-time cyclical effect can just be fine-tuning for trend effect and long-time effect.