| Due to the rapid urbanization process and the improvement of living standards,the contradiction between transportation demand and supply is becoming increasingly prominent.In order to solve the problesm of urban land conflicts and traffic congestion,rail transit has become the prior solution.However,it is accompanied by serious energy consumption.Continued environmental pressure puts forward sustainability requirements for the energy performance of rail engineering construction projects in their life cycle and regional eco-economic environment.At present,most of the existing energy consumption research for large-scale engineering construction projects focuses on the micro level,ignoring the flow of material resources related to economic,social and human activities in the regional eco-economic system.This study scientifically plans the scale of urban rail transit construction at the regional level,based on emergy theory and combined with input-output analysis methods,to improve the ecological efficiency evaluation method of large-scale infrastructure for regional energy efficiency,and takes urban rail transit as an empirical research object.It provides a new tool and relevant policy recommendations for government and related departments to make decisions.On the basis of life cycle theory,taking Xiamen Rail Transit Line 3 as the research object,using the energy analysis method to sort out the energy logistics,currency flow of each component and their interrelationships,the energy structure of rail transit construction projects was decomposed.Then,it was expanded to the energy accounting of the rail transit system in Fujian Province.Combining emergy theory with inputoutput analysis methods,a hybrid emergy input-output table and related emergy consumption coefficients are constructed.Based on SEEA’s accounting classification principles,the emergy consumption of rail transit is calculated according to input,while industrial classification of accounting is listed so that specific economic activities correspond to their emergy consumption,which provides an effective statistical coordination framework for studying the interaction between emergy and economy.Subsequently,the emergy intensity coefficient and the environmental input-output model was used to complete the environmental emergy calculation of the current rail transit investment plan in Fujian Province,which providing a data basis for the comprehensive assessment of regional eco-economics.On the basis above,according the characteristics of the rail transit construction project and the ecological economic system in which it is located,an "economy-society-nature" multi-dimensional emergy evaluation index system was established to quantitatively analyze the sustainable development level of Fujian Province under the rail transit construction activities,and put forward corresponding countermeasures.The results show that the main emergy consumption during the construction period of rail transit projects is non-renewable products such as construction materials.And main emergy consumption during the operation period is services and labor.The transportation and postal sector,construction sector,power and heat production sectors are the key components of emergy consumption.These sectors show a strong dependence on the consumption of non-renewable resource products with low energy efficiency,while energy consumption in agriculture and other light industries and service industries is relatively low.Under the influence of rail transit,the emergy output rate,purchase emergy ratio,emergy density and per capita efficiency value usage of Fujian Province have been effectively improved,as well as the production efficiency and competitiveness of economic activities in the region.However,such rapid development relies on the massive use of non-renewable resources,which has reduced the regional sustainability.In a long run,it will be an unsustainable way of development. |
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