基于RS和GIS的济宁市土地利用变化及生态安全研究

在RS/GIS技术的支持下,选择南四湖流域典型市域——济宁市为研究区,基于多源数据,揭示了研究区1987～2008年的土地利用时空变化特点,进一步构建"隐患-状态-免疫"的生态安全评价指标体系,采用组合赋权法确定指标权重,应用改进TOPSIS模型实现了100 m×100 m栅格水平上的生态安全综合评价。结果表明:研究区土地利用变化较为剧烈且具有独特的区域特色,其总体特征为耕地、林地、草地和未利用地的面积持续下降,建设用地急剧扩张,水域面积则先降后升;20 a来,研究区生态安全状况经历了先恶化后改善的变化趋势,南水北调工程的实施、环境治理和生态建设加大是2000年后研究区生态安全好转的主要驱动力;研究区生态安全状态空间差异明显,东部山地丘陵区和南四湖区最好,中部和西北部地区最差,其余区域基本处在预警状态。研究结果可为研究区生态建设和土地生态安全格局的制定提供依据。

Land Use Change and Ecological Security Assessment in Jining City Based on RS and GIS

The research on ecological security of land use is the core of IGBP and IHDP,which can provide a lot of guidances on the regional ecological construction and sustainable development.Based on RS and GIS technology,taking typical Jining City in Nansi Lake watershed as the study area,the paper analyzed land use change in Jining City from 1987 to 2008,and then an evaluation index system was established on basis of "Hazard-State-Immune"model.AHP and entropy methods were used for determining index weights,finally improved TOPSIS method was used to evaluate ecological security on 100 m×100 m grid scale in the year of 1987,2000 and 2008.The results of the study were as follows: 1)the change of land use in study area from 1987 to 2008 was great,and had typical regional characteristics.The areas of farmland,woodland,grassland and unused land kept decreasing,construction land expanded largely,water area first decreased and then increased.2)In the past 20 years,ecological security in study area changed from deterioration to improvement,experiencing V-shaped process,and the main reasons of improvement since 2000 were implementation of the South-to-North Water Transfer Project as well as enhancement of ecological construction.3)The spatial difference of land ecological security in research area was obvious,the best places were located in the eastern hilly area and Nansi Lake,the worst places were located in the middle area,and the remaining areas were in a warning state.This study revealed temporal evolution and spatial distribution of the land use and ecological security in Jining city,which played a conducting and reference role in ecological construction,regional sustainable development,and improving water quality standards of the East Route of the South-to-North Water Transfer Project.