基于土地利用变化的盐城海岸带生态风险评价

Ecological risk assessment based on land use changes in the coastal area in Yancheng city

在GIS和RS技术支持下,以行政区划为评价单元,从景观结构角度构建生态风险评价模型,借助地统计分析及空间自相关分析方法,对盐城海岸带地区2000-2010年景观生态风险的时空分异特征进行定量评价。结果表明:2000-2010年,盐城海岸带地区整体生态环境质量有所下降。10年间,研究区生态风险平均值从0.35增长至0.39,高等级生态风险区不断增加。土地利用生态风险程度整体空间分异性不断增加,局部呈现高—高聚集和低—低聚集。较高风险区和高风险区主要分布于射阳县、大丰市大丰港以北的沿海区域以及东台弶港附近,其原因主要是随着沿海开发的推进,临港产业和临海城镇的发展,海岸带土地利用变化加剧,沿海地区生态系统稳定性被破坏。

Based on remote sensing data and land use data supported by the GIS and RS technologies, the land use changes and its transformation have been quantitatively analyzed in the coastal area in Yancheng city during 2000-2010. Furthermore, considering the land use changes and landscape structures with the help of geostatistical analyst and spatial autocorrelation analysis, the ecological risk assessment model has been set up. Thus, we quantitatively evaluated the spatial and temporal dynamic changes of landscape ecological risk. It is shown that the average ecological risk value of the entire region was 0.35 in 2000, and increased from 0.36 in 2005 to 0.39 in 2010. In recent 10 years, the moderate ecological risk level covered the biggest area of the study area; the area of extremely low risk and low ecological risk had no obvious change and mainly located in inland area; the area with high risk and extremely high risk expanded, and its proportion of the total land from 0 in 2000 rose to 14.89% in 2010; the area of high ecological risk increased significantly and was mainly distributed in coastal zone of Sheyang, Dongtai and Dafeng; the degree of ecological risk showed the banded structure clearly, and increased seawards. With the economic boom, especially port industry and new town development in the coastal areas, land use has intensively changed; as a result, the ecological risk increased continuously.