Xingpeng Chen

Emergy-based study on eco-economic system of arid and semi-arid region: a case of Gansu province, China

: Taking Gansu province as a model case, this study provides an integrated analysis on the eco-economic system of arid and semi-arid region based on emergy synthesis theory. Through calculating the values of renewable emergy flow, non-renewable resources, imported emergy, exported emergy, waste emergy, and total emergy during the period of 1978-2007, the performance of Gansu eco-economic system was analyzed. The results indicated that the renewable emergy flow within the province basically remained steady state which was estimated at 2.99x10(22) solar emjoules (sej) from 1978 to 2007. The imported emergy and exported emergy were estimated at 3.75x10(17) sej and 2.99x10(20) sej in 1978 and increased to 1.07x10(22) sej and 1.44x10(22) sej respectively in 2007. The nonrenewable emergy flow was estimated at 1.62x10(22) sej and increased to 1.85x10(23) sej, with annual growth rate of 8.7%, while the estimated total emergy was 4.58x10(22) sej in 1978 and increased to 2.11x10(23) sej in 2007, with annual growth rate of 5.41%. Our results indicate a deteriorate situation between economic development and environmental protection in the region. The rapid economic growth in the past thirty years was based on a great consumption of nonrenewable resource and caused continuous decrease in the capacity of sustainable development. The environmental loading ratio was 0.53 in 1978, increased to 6.06 in 2007, indicating a rapid degradation of the regional environment quality. We calculated that the actual population was 1.53 times the renewable resource population in 1978, increased to 7.06 times in 2007. During the period of 1978-2007, the emergy rose from 2.45x10(15) sej/(capita.a) to 8.07x10(15) sej/(capita.a). Our analysis revealed that the emergy density presented a trend of gradual increase, and then the emergy currency ratio in Gansu decreased from 7.08x10(13) sej/Chinese Yuan to 7.82x10(12) sej/Chinese Yuan.

County Sustainable Development and Management in Gansu Loess Plateau Based on Emergy Analysis--Taking Zhengning County in Gansu Province as an Example

Zhengning County in Gansu Province, the cradle of traditional farming culture, is abundant in coal resource and solar energy, but it is ecologically fragile and has significant ecological service function, therefore facing the dual pressure of resource exploitation and environmental protection. Based on the analysis of main emergy indices of Zhengning eco-economic system during the past 20 years, this paper evaluates the efficiency of material metabolism and the capability for sustainable development, and puts forward sustainable management to promote the rapid and harmonious development of west Chinas counties.

Study on Meta Index in the Process of Evaluating Regional Sustainable Development

This article analyzes the shortage of existent index systems of regional sustainable development. The concept of meta index is put forward for the first time. The article describes the feature of meta index. Based on meta index, the concept of secondary index is also put forward. Based on meta index and secondary index, this paper classifies the evaluating indicators of regional sustainable development, and a case is given. After the classification, the connotation of index is clearer, and the selection of index is more scientific.