Research on the dynamic change of industrial eco-efficiency of mining cities based on emergy analysis——A case study of Jiangxi Province

The industrial development of mining cities inevitably brings about many environmental problems while promoting economic growth. Hence the key to promoting the industrial transformation of mining cities is to reasonably assess the environmental impact and sustainable development level of the cities' industrial systems. By virtue of the characteristic that emergy analysis can be used to measure and compare the real values of different types and levels of energy, the emergy flows of industrial systems of three mining cities (Xinyu, Pingxiang and Ganzhou) in Jiangxi Province from 2009 to 2018 are calculated, and the trends of emergy efficiency and ecological efficiency indexes are analyzed. The results show that the industrial development of the three cities mainly depends on local environmental resources and their whole system are not fully open to the outside. Xinyu has the highest emergy self-sufficiency rate, followed by Pingxiang, and the lowest is Ganzhou. The evaluation of emergy investment rates of the three cities turns out to be a surprise: the net emergy output rates of Pingxiang and Ganzhou are significantly lower than that of Xinyu; the sustainable development levels of the three cities are significantly low as their industrial activities impose too much burden on the environment that are beyond the recovery capacity of the ecosystem. Nevertheless, the ecological efficiency shows a good trend of steady rise. In the future, while making full use of local resources, the three mining cities should be open wider to the outside world and vigorously develop green economy and circular economy to reduce the pressure on the environment and promote the sustainable development of industrial system and the continuous increase of ecological efficiency.