大型城市紧凑度与能源效率的关系研究

采用超效率DEA和熵值法测算了2003—2014年29个大型城市的能源效率与紧凑度,进而通过象限图法对城市紧凑度与能源效率的关系进行分析。分析表明,我国大型城市能源效率普遍偏低但在缓慢提升;城市紧凑度与能源效率以低级协调为主。从区域看,二者关系的地区差异明显,东部以高级协调为主,中西部低级协调关系显著。城市规模越大,紧凑度和能源效率水平越高,且城市突出关系类型由低级协调变为高级协调。剔除紧凑度外其他可能影响能源效率的因素后的象限图再次印证提高紧凑度有利于改善城市能源效率的结论。为通过提升城市紧凑度来提高能源效率,需加大公共服务和基础设施投入,加强工业用地的集约使用,完善城市功能体系,实现经济、人文和生态的多功能复合利用。

A Study on the Relationship between Compactness and Energy Efficiency in Large Cities

Since the reform and opening up, the urbanization rate in China has risen about 40% from 1978 to 2016, and it has been rapidly advancing at a rate of 0.5 percentage points higher than the world average each year. In the process of city booming, there inevitably exist problems such as extensive land use, urban sprawl and excessive energy consumption. In recent years, environmental pollution such as haze caused by excessive energy consumption has impacted seriously on the life quality of urban residents, and the problem is even more serious in large cities. In western countries, it has been proved that compact city is an effective development mode in alleviating energy shortage and environmental pollution in large cities. However, the concept of compact city has not been given enough attention in China. In this paper, we focused on the relationship between energy efficiency and compactness. The energy efficiency and compactness of 29 large cities during 2003-2014 were measured with super-efficiency-DEA model and entropy value method, and then quadrant map approach was introduced to explore the relationship between urban compactness and energy efficiency. The results showed that energy efficiency was relatively low but was increasing slowly. The regional disparities of the relationship between urban compactness and energy efficiency were significant. The eastern part of China mainly had high coordination relationship, while the middle and western part of China mostly had low coordination relationship. From the perspective of the scale of cities, larger cities had higher energy efficiency. As the city size increased, the proportion of high coordination type became higher and higher. Megacities mostly fell into the categories of high coordination, and small cities mostly fell into the categories of low coordination. The quadrant diagram analysis after eliminating other possible affecting factors showed more obvious result that more compact city had higher energy efficiency. To improve the energy efficiency, multi-functional composite utilization of economy humanity and ecology should be realized by putting more investment into the construction of public service facilities and infrastructure, intensifying industrial land use and perfecting the functional system of cities.