关键词: 生态效率, DEA, SBM, 时空分异格局, 松弛度分析, 东部沿海地区四大城市群

Abstract:

Nowadays, the urban agglomerations in the eastern coastal area of China have been the strategic core regions of national economic development and part of the main regions of the new-type urbanization. However, they suffer a series of eco-environment problems, such as increased consumption of resources, energy and materials. Thus, over the past few years, the eco-environment problem of urban agglomerations has become the forefront subject in the field of geographical research. The paper is unfolded with the definition of the eco-efficiency of urban agglomeration, which is taken as the measurement index of sustainability of urban agglomerations. Subsequently, with the aid of the traditional DEA model and undesirable output model of SBM, the paper carries out a comparative evaluation of the economic efficiency and ecological efficiency of the four major urban agglomerations in eastern China in the three periods of 2005, 2011 and 2014, and analyzes the spatio-temporal characteristics of evolution of urban agglomerations. In conclusion, with an analysis of laxity, the paper proposes corresponding suggestions for the improvement of eco-efficiency of the four major urban agglomerations in coastal China. As is suggested in the results, first and foremost, the overall economic efficiency of urban agglomerations located in Shandong Peninsula, Yangtze River Delta and Pearl River Delta displays a V-shaped pattern of "first decrease and then increase". In contrast, the overall economic efficiency of the Beijing-Tianjin-Hebei urban agglomeration declines from the beginning to the end. Before 2011, a significant impact of pure technical efficiency is displayed, and after 2011, it is greatly affected by scale efficiency. Secondly, the Beijing-Tianjin-Hebei urban agglomeration suffers from a considerable loss of efficiency due to the impact of pollution. In contrast, there is a less severe loss in the efficiency of Shandong Peninsula urban agglomeration. On the whole, the eco-environment efficiency of the four major urban agglomerations was at a descending stage from 2005 to 2011, and at a revival stage from 2011 to 2014. In addition, the spatio-temporal pattern of urban eco-efficiency in the four major urban agglomerations in the coastal areas is possessed with different evolution characteristics. The peri-urban areas of core cities and riverside and seaside areas have a better urban eco-efficiency, and the inland cities have an inferior urban eco-efficiency. Apart from that, it is found that the core cities of the Beijing-Tianjin-Hebei, Yangtze River Delta and Pearl River Delta urban agglomerations have a high resource consumption, economic benefit output and high eco-efficiency. Overall, most cities in the urban agglomerations demonstrate a declining tendency of pollution emissions, together with marked reduction of pollutants and mitigation of environmental problems. Last but not least, the economic eco-efficiency of the four major urban agglomerations is influenced by different factors. The paper conducts a differential analysis from the perspective of urban agglomeration, and proposed the concrete suggestions.

Key words: eco-efficiency, data envelopment analysis, undesirable SBM, spatio-temporal pattern, slacks analysis, four urban agglomerations of eastern China