基于PSR模型--熵权法的土地生态安全时序评价--以衡阳市为例

Evaluation and Dynamic Analysis of Land Ecological Security Based on PSR Model——Taking Hengyang City as An Example

以衡阳市为例,从影响土地生态安全的因素出发,结合衡阳市的经济与生态特点,针对衡阳市近12年的土地资源生态安全状况,选取了森林覆盖率、污水处理率、空气质量达标天数等20个土地生态安全评价指标,利用"压力-状态-响应"模型,即PSR模型,对衡阳市近12年的土地生态安全进行动态分析与评价。结果表明:衡阳市土地安全综合值从2007年的0.298 0上升到2018年的0.839 2,近12年来衡阳市土地生态安全水平总体呈上升趋势;从2007年到2013年,前7年衡阳市的土地生态安全情况不容乐观,而后5年土地生态安全状态明显好转并不断健康发展,衡阳市土地生态安全从较不安全等级转化为安全等级,生态系统结构也逐渐趋于稳定。研究认为:加强对林地草地等的保护;控制人口增长,缓解人地矛盾;发展绿色经济,完善配套设施等对建立土地利用规划评价体系与土地生态系统长效治理机制具有参考作用。

Taking Hengyang city as an example,starting from the factors of land ecological security,this paper combined with the characteristic of the regional economy and ecology on the basis of the land ecological security state and latest research results at home and abroad.Aimed at almost 12 years in Hengyang ecological security of land resources,the“pressure-state-response model(PSR model)”has been constructed,and 20 comprehensive evaluation indexes of land ecological security have been established,such as the forest coverage rate,sewage treatment,urban built up area greening area and so on.In this paper,the land ecological security of Hengyang in recent 12 years have been dynamically analyzed and evaluated.The results show that the Hengyang land security comprehensive value from 0.3616 in 2007 to 0.7670 in 2018.The land ecological level of Hengyang in nearly 12 years is generally on the rise from 2007 to 2018.The first six year land ecological security situation of Hengyang is not optimistic,meanwhile,the second six years of land ecological security condition improved markedly and continuous healthy developed.The results of the study imply that land pressure of Hengyang is rising,at the same time,the land ecological security situation continues to improve,the urban land ecological security level is changed from unsafe to safe and the ecological structure is gradually stabilized as well.Some referential suggestions are put forward,such as,strengthening the protection of forest and grassland,controlling the population growth,relieving the contradiction between people and the land,developing green economy and improving the supporting facilities which have referential role for the establishment of the evaluation system of the land planning and the long-term mechanism of the land ecosystem management.