土地整治项目对农田生态系统影响的能值分析

发布时间：2019-08-15 17:29

【摘要】：为在项目尺度构建土地整治农田生态系统能值分析框架,以江苏省宜兴市土地整治项目作为案例,根据设定的土地整治工程使用年限,从项目建设-使用过程和项目全生命周期2个时间维度,对土地整治工程建设对农田生态系统的影响进行了研究。结果表明:在项目建设-使用过程维度,1)项目建设期大量物料投入和电力等资源输入,导致能值投入加大,能值产出下降;2)受土地整治影响,项目建设导致农田生态系统自给能力减弱,对外界经济投入依赖度增加,净能值产出率下降,环境负载率增大,农田生态系统可持续发展能力下降;从生命全周期来看,3)由于土地整治工程的影响,各项能值指标在项目建设期出现陡增和陡降现象,随着土地整治工程竣工以及效益发挥,各项能值开始趋于平稳,并在全周期末各项指标优于土地整治前各项指标,全生命周期内预计给农田生态系统带来2.23E+19sej能值产出和60.15万美元能值-货币价值。综合而言,土地整治在项目建成后的10年内对项目区农田生态系统具有积极影响,但此后,可能将对项目区的生态环境造成了一定的压力。
[Abstract]:In order to construct the emergy analysis framework of land renovation farmland ecosystem at the project scale, taking the land regulation project in Yixing City, Jiangsu Province as an example, according to the set use life of land regulation project, the influence of land regulation project construction on farmland ecosystem was studied from two time dimensions: project construction-use process and project life cycle. The results show that: in the dimension of project construction-use process, 1) a large number of material input and power input during the project construction period, resulting in the increase of emergy input and the decrease of emergy output; 2) affected by land regulation, the project construction leads to the weakening of self-sufficient ability of farmland ecosystem, the increase of dependence on external economic input, the decrease of net emergy output rate, the increase of environmental load rate and the decrease of sustainable development ability of farmland ecosystem. From the life cycle point of view, 3) due to the influence of land regulation project, the emergy indexes increase sharply and drop sharply during the construction period of the project. With the completion of the land renovation project and the display of benefits, the emergy values begin to become stable, and at the end of the week, the indicators are better than those before the land renovation. It is expected to bring 2.23E 19sej emergy output and $601500 emergy-monetary value to farmland ecosystems throughout the life cycle. To sum up, land remediation has a positive impact on the farmland ecosystem in the project area within 10 years after the completion of the project, but after that, it may cause some pressure on the ecological environment of the project area.
【作者单位】：南京大学地理与海洋科学学院;
【基金】：教育部博士点基金(20120091110014) 江苏省自然科学基金(BK2012731)
【分类号】：F301.24

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