资源型城市土地利用变化及生态安全数字模拟

东营市是新兴的石油资源城市,且处于海陆变迁活跃、自然灾害频繁和生态环境脆弱的黄河三角洲地区,使其形成了资源型城市与滨海生态脆弱型城市的"复合体",人地作用关系强烈,土地利用/覆被变化剧烈且具有独特的区域特征.探讨该地区的土地利用/覆被变化与生态安全的内在规律,有着重要的现实意义.为此,运用RS和GIS技术,对东营市1996、2005年两个时段土地利用/覆被变化及生态安全空间演变规律比较分析,并对生态安全空间变化格局进行了数字模拟.研究结果表明:耕地是东营市主要的土地利用类型,面积有所减少;未利用地和次生盐碱地所占比重较大,居民点及工矿用地大幅增加,油田生产建设和生态环境保护矛盾非常突出.生态安全风险总体上有进一步恶化的趋势,生态风险重心已经由南部的广饶地区转移到中部的东营地区.油田及其相关产业的发展成为生态安全风险上涨的主要原因,而湿地生态系统的破坏和功能减退,草地退化,土地盐碱化等也对生态环境造成了巨大压力.

Digital simulation of land use change and ecological security of resources-based city

Dongying is a developing petroleum resource city, the reason that locates in the Yellow River Delta where sea-land change activity, natural disasters aggravate and ecological environment fragility make it the composite of resource-based city and coastal ecological fragility city. The man-land relationship tension and land use/cover change have unique regional character, so it is practical significance to analysis the land use/cover change and the internal rule of ecological security. Based on RS and GIS techniques, the land use/cover change and the spatial evolvement rules of ecological security in 1996 and 2005 were studied, and the digital simulation of ecological security spatial evolvement pattern was conducted. The results indicate that the cultivated land was the primary type, the proportion of unused land and secondary saline habitat were much bigger, the proportion of residential and mining land increased quickly, and the conflict between the producing-construction of oilfield and eco-environment conservation was keen-edged in the recent ten years. The ecological security risk was worsen, the center of ecological risk had transferred from the district of Guangrao to Dongying, oil field and the correlative industry became the main reason of the ecological risk increasing, at the same time, the tremendous pressure of eco-environment came form the breakage of wetland ecosystem, grassland degradation and land salinization.