基于土地利用的陕西省生态风险分析

土地利用变化对陆地生态系统产生了很大的影响。利用陕西省土地和社会经济环境资料,分析了土地利用变化趋势。采用层次分析法与综合指数法,建立了自然压力、社会环境压力、经济压力生态风险指标体系,估算了耕地、林地、牧草地、水域等土地利用结构生态风险以及综合风险。结果表明,绝对数量变化幅度最大的是耕地和林地,而且耕地生态风险最大,水域变化生态风险最小,不同土地利用类型生态风险指数大小顺序为：耕地〉林地〉居民点及工矿用地〉牧草地〉未利用地〉交通用地〉水利设施用地。土地生态压力风险中,以经济压力生态风险最大,其次是自然压力生态风险,社会环境压力生风险相对较小,土地生态综合风险呈增加趋势。生态风险变化与土地利用结构的不合理,人口增加,水资源量减少以及自然灾害增加密切相关。

Ecological Risk Analysis Based on Land Use in Shaanxi Province

Changes of land use have great impacts on terrestrial ecosystems.The trends of land use changes were analyzed based on the land,social,economic,and environmental data.Using the methods of the composite index and analytic hierarchy process(AHP),we established the ecological risk assessment systems considering natural,societal,and economic pressure,and evaluated ecological risk index and composite risks of land use structure including cultivated lands,forestlands,grazinglands,and water body.The results showed that the ecological risks were the greatest in cultivated lands,and smallest in water bodies.T he order of the risks is:cultivated land>woodland>land for inhabitation,mining and manufacturing > grazing and pasture land>unutilized land>land for transport facilities>land for water conservancy facilities.The ecological risks caused by economic pressure,nature pressure,and society pressure were greatest,intermediate,and smallest,respectively,while composite risk increased.The ecological risks are related to an unreasonable structure of land-use,increase in population,decrease in water resources and increase of natural disaster.