重庆市黔江区土地生态安全评价及时空变化分析

目的]揭示重庆市黔江区土地生态安全的时空变化特征,为黔江区土地资源的可持续利用提供科学依据。方法]从生态负荷、生态保护、生态功能及生态经济4个方面构建黔江区土地生态安全评价指标体系,采用主客观组合赋权和综合指数法对该区土地生态安全状况进行分析。结果](1)研究区土地生态安全水平呈上升趋势,但总体水平不高,有待进一步改善;(2)黔江区土地生态安全空间差异显著,呈现"区中心土地生态安全水平低,四周土地生态安全水平较高"的土地生态安全格局。结论]主客观组合赋权有助于克服单一的主观赋权及单一客观赋权的不足;将"压力—状态—响应(PSR)"模型和"自然—经济—社会"模型有机结合构建的基于生态负荷、生态保护、生态功能及生态经济的评价指标体系较好地反映了黔江区土地生态安全的时间变化及空间差异状况。

Spatiotemporal Change Analysis and Land Ecological Security Evaluation in Qianjiang District of Chongqing City

Objective] The spatiotemporal variation pattern of land ecological security of Qianjiang District of Chongqing City was studied to provide scientific basis for the sustainable utilization of land resources. Methods] An evaluation system of land ecological security of Qianjiang District was configured from four aspects of ecological load, ecological protection, ecological function and ecological economy. Methods of subjective and objective combined weight assignment and comprehensive index were used. Results] Though the land ecological security level of Qianjiang District was not high enough, it was on the rise trend, and there was a big space for it to be improved. The spatial difference of the land ecological security had an obvious pattern with low center and high surrounding areas. Conclusion] The subjective and objective combined weight assignment overcame the deficiency of single subjective or single objective assignment. The evaluation index system included ecological load, ecological protection, ecological function and ecological economy, and combined with the press-state-response(PSR) model and nature-economy-society model, hence, it could effectively reflect the temporal dynamic change and spatial difference of Qianjiang''s land ecological security.