基于显隐性分析的青龙满族自治县景观生态风险评价空间分异研究

Study on Landscape Ecological Risk Assessment and Spatial Differentiation of Qinglong Manchu Autonomous County Based on Explicit and Implicit Analysis

景观生态风险评价可揭示区域生态风险的时空变化规律,对维护区域生态安全和优化环境管理有重要意义。从景观生态风险的显隐性角度出发,选取不同的因子作为评价指标,构建了景观生态风险评价指标体系,结合GIS,Geoda等空间分析技术,并以青龙满族自治县为研究区域,进行了景观生态风险评价和空间相关性分析,揭示了景观生态风险时空分布格局。结果表明:景观斑块的破碎化等显性风险是区域风险升高的直接原因,而隐性风险例如长久以往的人类活动干扰而导致的生态系统结构稳定性的破坏无疑是诱因;2001—2013年,青龙满族自治县整体景观生态风险呈下降趋势,但风险指数仍处于较高等级,空间分布上风险等级呈西部高东部低的特征;研究期间景观生态风险指数在空间上存在着较强烈的空间自相关性,且HH聚类和LL聚类呈增强趋势;通过对风险变化区的地类变化分析可知,林地对于区域景观生态风险值的变化起着至关重要的作用,林地面积的增加有效降低了区域景观生态风险值,而未利用地对生态风险指数变化也有重要影响,应控制未利用地合理、适时、适度地开发。研究结果为研究区以及类似地域景观生态风险管理和土地利用生态布局提供参考。

Landscape ecological risk assessment can reveal the temporal and spatial variation of regional ecological risk,which is of great significance for the maintenance of regional ecological security and the optimization of environmental management.We selected different factors as evaluation indexes from the perspective of explicit about the landscape ecological risk to construct the landscape ecological risk evaluation index system.Combining with GIS,Geoda and other spatial analysis techniques,and taking Qinglong Manchu Autonomous County as the research area,we carried out the landscape ecological risk assessment and spatial correlation analysis to reveal the spatial and temporal distribution pattern of landscape ecological risk.The results showed that the fragmentation of landscape patches and other explicit risk were the direct cause of regional risk increase,while the implicit risks,such as the destruction of the stability of the ecosystem structure caused by human disturbance for a long time,were undoubtedly the inductive factors;during the 2001-2013,the overall landscape ecological risk in Qinglong Manchu Autonomous County declined,but the risk index was still at a higher level,and the characteristics of risk grade was high in the west and low in the east;there was a strong spatial auto-correlation between the landscape ecological risk indices during the study period,and HH clustering and LL clustering showed the increasing trend;through the analysis of the change of land type in the risk change areas,we could know that the forestland played an important role in the change of regional landscape ecological risk value,and the increase of forest land area effectively reduced the regional landscape ecological risk value,and the unused land also had an important influence on the change of ecological risk index,so the unused land should be controlled reasonably,timely and moderately.The results can provide the reference for landscape ecological risk management and ecological layout of land use in the study area and the similar areas.