基于探索性空间数据分析的海坛岛土地利用生态风险评价

生态风险评价作为一种新型环境管理工具，提供了定量化评估土地利用变化生态效应的新视角.本研究以福建海坛岛为案例区，基于1990年Landsat TM与2010年SPOT5遥感影像、2030年平潭综合试验区总体布局规划图和野外调查等数据，构建度量生态终点的生态风险表征指数，运用探索性空间数据分析中的空间自相关和半方差分析方法，对海坛岛过去 现在 未来不同土地利用情景下生态风险进行评价，分析其潜在的风险性及其变化趋势.结果表明： 海坛岛生态风险指数存在明显的尺度效应，在3000 m范围内表现出较强的正相关，生态风险指数空间分布以高 高聚集和低 低聚集类型为主；生态风险指数具有显著的各向同性特点，且其空间分布与对应时期局部空间自相关指数分布模式一致；各生态风险等级区年际变化较为剧烈，波动态势与波动幅度均有所不同；低生态风险区呈先增后降趋势，中、高生态风险区呈先降后升趋势.规划期的人为扰动强烈，高生态风险区在整个区域扩展蔓延.为减低土地利用生态风险、维护区域生态安全，可采取的生态风险控制策略包括：优化土地资源空间格局、保护关键生态区域、控制建设用地规模.

Ecological risk assessment of land use based on exploratory spatial data analysis (ESDA): A case study of Haitan Island,Fujian Province.

As a novel environment management tool, ecological risk assessment has provided a new perspective for the quantitative evaluation of ecological effects of land use change. In this study, Haitan Island in Fujian Province was taken as a case. Based on the Landsat TM obtained in 1990, SPOT5 RS images obtained in 2010, general layout planning map of Pingtan Comprehensive Experimental Zone in 2030, as well as the field investigation data, we established an ecological risk index to measure ecological endpoints. By using spatial autocorrelation and semivariance analysis of Exploratory Spatial Data Analysis (ESDA), the ecological risk of Haitan Island under different land use situations was assessed, including the past (1990), present (2010) and future (2030), and the potential risk and its changing trend were analyzed. The results revealed that the ecological risk index showed obvious scale effect, with strong positive correlation within 3000 meters. High high (HH) and low low (LL) aggregations were predominant types in spatial distribution of ecological risk index. The ecological risk index showed significant isotropic characteristics, and its spatial distribution was consistent with Anselin Local Moran I (LISA) distribution during the same period. Dramatic spatial distribution change of each ecological risk area was found among 1990, 2010 and 2030, and the fluctuation trend and amplitude of different ecological risk areas were diverse. The low ecological risk area showed a rise to fall trend while the medium and high ecological risk areas showed a fall to rise trend. In the planning period, due to intensive anthropogenic disturbance, the high ecological risk area spread throughout the whole region. To reduce the ecological risk in land use and maintain the regional ecological security, the following ecological risk control strategies could be adopted, i.e., optimizing the spatial pattern of land resources, protecting the key ecoregions and controlling the scale of construction land use.