基于PSR模型的土地利用系统健康评价及障碍因子诊断

HEALTH EVALUATION ON LAND USE SYSTEM BASED ON THE PSR MODEL AND DIAGNOSIS OF ITS OBSTACLE INDICATORS

土地利用系统健康评价及障碍因子诊断是土地资源可持续利用的重要基础。在界定土地利用系统健康内涵的基础上,构建了基于PSR模型的评价指标体系,采用熵值法和障碍度模型,对四川省土地利用系统健康进行了评价。研究结果表明:(1)2000～2008年四川省土地利用系统健康水平总体不断提高,综合指数从0.394 5增加到0.557 3,健康等级经历了"不健康-临界状态"的演变历程;(2)压力指数总体上呈现下降趋势,状态指数和响应指数总体上呈现上升趋势;(3)长远来看,系统压力是影响土地利用系统健康的首要因素,2000～2008年系统压力和系统状态的障碍度分别以年均8.81%和0.97%的速度增加,而系统响应的障碍度以年均7.66%的速度下降;(4)影响土地利用系统健康的主要障碍因子包括固定资产投资增长率、人均耕地面积、土地垦殖率、水土流失程度、地均GDP等。为了促进土地利用系统健康水平不断提高,需要进一步转变经济发展方式,加强土地利用监督管理,加大环境治理力度,有效控制水土流失程度。

Health evaluation on land use system and diagnosis of its obstacle indicators would be greatly helpful for sustainable land use. On the basis of defining the meaning of health on land use system,the eval- uation index system was constructed based on the PSR model, then an empirical analysis was conducted in Sichuan province by entropy method and obstacle degree model. The results showed that the health degree of land use system had been gradually improved from 2000 to 2008,with the index increasing from 0. 394 5 to 0. 557 3. The degree of land use system generally experienced two stages, i. e. , unhealthy and critical state. The pressure index overally showed a downward trend,while status index and response index a rise trend. In the long run,the system pressure was found to be the major factor affecting health on land use system. The obstacle degree of system pressure and system status increased by an annual average of 8.81 and 0. 97%,respectively, but the obstacle degree of system response decreasesd by an annual average of 7.66 %. The growth rate for fixed asset investment, per capita arable land, land reclamation rate, extent of soil erosion and per capita GDP were verified to be the key obstacle for further improvement of health on land use system. The health on land use system was continuously improved by further transformation of economic development mode, strengthening supervision and management for land utilization, increasing the intensity of environmental governance, effectively controlling soil erosion, and so on.