| Evalution of sustainability for farmland ecosystem of Gaotai County based on emergy analysis |
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| DOI：10.7606/j.issn.1000-7601.2016.04.39 |
| Key Words: gaotai emergy analysis farmland ecosystem sustainable development principal component analysis |
| Author Name | Affiliation | | LIU Shui-qin | Department of Resources and Environment, Gansu Agricultural University, Lanzhou, Gansu 730070, China | | WANG Wan-xiong | Department of Resources and Environment, Gansu Agricultural University, Lanzhou, Gansu 730070, China | | ZHANG Jie-qiong | Department of Resources and Environment, Gansu Agricultural University, Lanzhou, Gansu 730070, China |
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| Abstract: |
| Input and output structure and emergy indexes of the farmland ecosystem in Gaotai were investigated using the theory of emergy analysis and principal component analysis. The results indicated that total emergy input of the oasis farmland system in Gaotai County was overall increased, whereas went decreased in certain period. The lowest input value was 325×1018 sej in 1998, while it reached a maixium of 496.89×1018 sej in 2012, mainly due to obvious increase of industrial emergy that changed from 180.98×1018 sej to 285.14×1018 sej. Emergy output exhibited a marked fluctuation pattern. It reached a minimum of 240.37×1018 sej in 2002 and a maximium of 473.37×1018 sej in 2012. Agricultural oasis ecosystem environment load rate was high and it became elevated from 1.11 in 1997 to 1.54 in 2001, and was then dropped to 1.39 in 2012. Sustainable development index of farmland in Gaotai oasis ecosystem was 0.53, which was lower than the national average level of 1.23 in 2001. Generally speaking, the comprehensive level of the ecosystem in Gaotai area was getting worse, dispaying strong variations during recent 16 years. The ecosystem was good from 1997 to 1999 in Gaotai, while the environment problems became crucial from 2000 to 2006. Though it had been improved from 2007 to 2009, in recent years, the sustainable development of oasis farmland ecosystem continued to be cruel. Agriculture is the basis for the development of Gaotai. Therefore, adjustment of the planting structure, rational exploration for water resources, protection on arable land, and active introducion of advanced machinery and technology should be implemented in the future to promote economic and social development. |
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