基于熵权物元模型的耕地占补平衡生态安全评价

Evaluation of eco-security of cultivated land requisition-compensation balance based on entropy weight and matter element model

  • 摘要: 针对目前耕地占补平衡生态安全评价中信息屏蔽和主观性问题, 该研究以重庆市永川区为例, 在构建耕地占补平衡生态安全评价指标体系的基础上, 结合物元分析法和熵权理论, 对其耕地占补平衡生态安全进行定量评价。熵权物元分析法包括构建评价指标体系、评价指标经典域、节域, 建立耕地占补平衡生态安全评价物元模型, 计算评价指标关联度, 确定相关指标权重等内容。研究结果表明: 2005年、2009年永川区耕地占补平衡生态安全级别为"较安全", 2015年和2020年永川区耕地占补平衡生态安全级别为"安全", 2005年、2009年、2015年和2020年永川区耕地占补平衡生态安全级别整体上呈现出由"较安全"向"安全"的提升趋势; 物元分析单指标评价结果表明, 永川区耕地占补平衡生态安全主要制约因子是人口密度、森林覆盖率、单位面积耕地农药负荷以及单位面积耕地化肥负荷等, 而耕地占补平衡生态安全主要促进因子则是人均耕地面积、耕地与其他土地比例、农民人均纯收入年增长率、GDP年增长率、第一产业产值年增长率、人口自然增长率等。此外, 为了验证熵权物元模型评价的可行性与合理性, 将其评价结果与模糊综合评价结果进行比较, 结果表明熵权物元评价结果与模糊综合评价结果基本一致, 虽个别年份有差异, 但未出现越级现象。与模糊综合评价相比, 熵权物元评价结果更为准确、合理直观, 能更细致地描述对象的生态安全等级, 为耕地占补平衡生态安全评价研究提供了一种简单实用且科学合理的评价方法。

     

    Abstract: This paper used Yongchuan District in Chongqing City as a case study to address the issues of method disunity, information shield and subjectivity of evaluation processes of eco-security of cultivated land requisition-compensation balance in China with the context and theory of entropy weight and matter element model. The entropy weight method included building systems of assessment factors; setting up factor fields for classifications of eco-security, entropy construction model and matter element analysis; relevancy calculations of factors and eco-securities of cultivated land requisition-compensation balance; and mapping out factor weights. The results showed that eco-security grade of cultivated land requisition-compensation balance for 2005 and 2009 was generally safe and for 2015 and 2020 was safe. The overall trend in eco-security of cultivated land requisition-compensation balance in Yongchuan District improved from general security to high security over the period from 2005, 2009, 2015 onto 2020. The key driving factors of eco-security of cultivated land requisition-compensation balance in the study area included population density, forest cover ratio, pesticide load per unit-area of cultivated land, chemical fertilizer load per unit-area cultivated land, etc. Also the key driving factors of eco-security of cultivated land requisition-compensation balance in Yongchuan District included per-capita cultivated land, cultivated/uncultivated land ratio, annual farmers' per-capital net income growth rate, annual GDP growth rate, primary industry annual growth rate, population natural growth rate, etc. Compared with fuzzy comprehensive evaluation, entropy weight and matter element analysis results were largely consistent. Although differences existed in individual years, leapfrog phenomenon was not apparent. This showed that the evaluation results of matter element analysis were visualized, reasonable and reliable. Also the matter element analysis was practical and the scientific evaluation method more meticulously described the evaluation process of eco-security of cultivated land requisition-compensation balance.

     

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