长株潭地区耕地生态安全评价研究

Evaluation for Ecological Security of Cultivated Land in Chang—Zhu—Tan Region

摘要:

耕地生态安全关系到可持续发展和粮食安全。以长株潭地区耕地为研究对象，基于改进的PSR模型构建耕地生态安全评价指标体系，运用组合赋权法确定指标权重，并对长株潭地区耕地生态安全进行定量分析和评价。结果表明，在2000—2012年，研究区域耕地生态安全综合指数从37.59增加到55.82，生态安全整体水平呈波动上升趋势。其中，压力指数由23.37下降到4.14，年均减少率为6.86%；状态指数从10.00增加到33.55，年均增长率为19.63%；响应指数从4.22增加到18.12，年均增长率为27.45%。影响耕地生态安全的主要因素是耕地环境质量指数、第一产业产值占GDP比重、单位耕地农业机械化水平、单位耕地粮食产量、环保投资额占GDP比重和当年造林面积。

Abstract:

The ecological security of cultivated land is related to sustainable development and food security. Evaluation on cultivated land ecological security is a significant foundation for improving the security of farmland ecosystems and sustainable use of cultivated land. The Changsha—Zhuzhou—Xiangtan (Chang—Zhu—Tan) region was chosen as study area. Fully considering the economical and social environment development of Chang—Zhu—Tan region, the original PSR model was improved according to characteristics of the study area. In the rule hierarchy of pressure, state and response, totally 17 evaluation indexes were selected in light of resource environment and social economy, and then the evaluation index system of ecological security assessment was fabricated. The index weight was determined by combination weighting approach which combined the subjective (analytic hierarchy process) with objective weighting method (entropy method). The ecological security of cultivated land in Chang—Zhu—Tan region from 2000 to 2012 was quantitatively evaluated and analyzed by the modified PSR model. The results showed that during 2000 to 2012, the comprehensive index of ecological security for cultivated land in Chang—Zhu—Tan region was gradually increased from 37.59 to 55.82, and the level of ecological security was fluctuantly increased. The pressure index showed a decreased trend with annual average of 6.86%, which was decreased from 23.37 to 4.14; fluctuate increase in state index was observed with annual average of 19.63%; the response index was increased from 4.22 to 18.12 with annual average of 27.45%. In view of security level of cultivated land ecological security, the ecological security of cultivated land in the area during 2000—2004 belonged to risk level, and that during 2005—2011 was sensitivity level, but it was risen to good level in 2012. The main factors that affecting the cultivated land ecological security in Chang—Zhu—Tan region were environmental quality index of cultivated land, the first industrial output in proportion to GDP, agricultural mechanical power of unit cultivated land, grain yield per unit of cultivated land, environmental protection investment in proportion to GDP and afforestation area of current year. Temporal and spatial variabilities of cultivated land ecological security were analyzed for every county in Chang—Zhu—Tan region. The associated suggestions to intensify protection of cultivated land, consolidate rural land, improve agricultural comprehensive production capacity, increase scientific and technological input in environmental protection and improve the quality of cultivated land, strengthen ecological construction, were proposed to increase the level of ecological security of cultivated land in Chang—Zhu—Tan region. Likewise, the local government was appealed to pay extensive attention to the cultivated land ecological security, and should take effective measures, such as working on comprehensive plan for land ecology and land use, economizing the intensivelyutilized cultivated land, realizing dynamical equilibrium of total cultivated land, strengthening protection of cultivated land in quantity and quality, improving environment around them and the level of ecological security of cultivated land. As so, the Chang—Zhu—Tan region was possible to become a comprehensive reform pilot area, as well as a national resource-saving and environment-friendly society.