[1]YANG Zhi-ping.Dynamic Analysis on Agri-ecological System of Yancheng City Based on Emergy Theory[J].Research of Soil and Water Conservation,2013,20(06):311-315,332.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
20
Number of periods:
2013 06
Page number:
311-315,332
Column:
Public date:
2013-12-28
- Title:
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Dynamic Analysis on Agri-ecological System of Yancheng City Based on Emergy Theory
- Author(s):
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YANG Zhi-ping1,2
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1. School of Urban Environment and Resources, Yancheng Teachers University, Yancheng, Jiangsu 224051, China;
2. Research Institute of Jiangsu Coastal Development, Yancheng, Jiangsu 224051, China
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- Keywords:
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agro-ecosystem; emergy theory; dynamic analysis; Yancheng City
- CLC:
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F323.22;X171
- DOI:
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- Abstract:
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Agro-ecosystem is the most basic system for human beings survival, while the analysis on the structure and function of the system is the key to solve the problems of agro-ecological environment. Based on the theories and methodologies of emergy, the emergy structure in agro-ecosystem about Yancheng City from 1995 to 2010 was studied. Some indicators of emergy were selected such as emergy input ratio, net emergy yield ratio, emergy environmental carrying capacity, emergy density, emergy per capita, emergy sustainable indices were assessed. The results showed that the agro-ecosystem gross input values of research area displayed the increasing trend. The wind resource input values added gradually but with low ratio. Because of the development of towns’ industrial and young rural people working in cities, the manpower resource input values decreased gradually. The agro-ecosystem gross input values of research area also showed the increasing trend. Traditional agriculture which is composed mainly by organic emergy such as manpower and livestock is being substituted for modern agriculture gradually, which is composed mainly by agricultural machinery, chemical fertilizer and industrial assistant emergy. Diversity of agriculture mode is also increasing with higher additional-value aquaculture industry. The sustainable development index of system emergy was 0.97, the system was a typical consumption-based ecological system, output emergy was obtained by consuming more resources. The system has a low sustainability and creates a large pressure on environment. It is necessary to adjust agricultural structure, adopt science and technology, develop environmental-friendly and ecological agriculture and obtain the object to keep sustainable development.