基于土地利用变化的江苏沿海地区生态风险格局

为探讨经济快速发展地区土地利用变化对生态系统造成的风险,以江苏沿海地区1990、2000、2010和2015年的遥感解译土地利用数据为基础,基于景观格局指数和生态环境脆弱度构建了区域生态风险指数,在Arc GIS和Fragstats软件支持下,借助地统计分析和空间自相关分析方法,定量评价江苏沿海地区1990—2015年区域生态风险的时空分异特征。结果表明:1990—2015年,江苏沿海地区整体生态安全状况有所好转,研究区生态风险平均值从0.1563减少至0.1529,该区主要处于中等级生态风险。生态风险等级降低区在较高风险区、中风险区和较低风险区均有分布,而等级升高区域主要集中在较低风险区与中风险区,即东部草地和水域地区以及西南部耕地地区,其原因主要是临海产业和临海城镇的快速发展造成土地利用变化加剧,导致生态系统平衡遭到破坏,生态风险加强。区域生态风险整体空间分异性增加,局部呈现高-高聚集和低-低聚集,其中高值聚集区主要由研究区西部外围边界处向南聚集,低值聚集区主要分布在研究区东北部和东部沿海地区。耕地、水域和建设用地是整个研究区生态风险的主要来源。研究结果为该区实现土地可持续利用、促进土地利用与生态环境的协调发展以及制定生态风险管理政策提供科学依据与技术支持。

Ecological risk pattern based on land use changes in Jiangsu coastal areas

In order to assess ecological risk caused by land use changes in a region with a rapidly developing economy, based on remote sensing data of land use in Jiangsu coastal areas in 1990, 2000, 2010, and 2015, this study analyzed the land use changes and its transformation, quantitatively supported by Geographic Information System(GIS). The present study built an ecological risk index based on the landscape disturbance index and vulnerability index, and then the spatial and temporal dynamic changes of landscape ecological risk were quantitatively evaluated using geostatistical analysis and spatial autocorrelation analysis. The results showed that the ecological security of Jiangsu coastal areas had improved, and the average ecological risk value of the entire region decreased from 0.1563 in 1990 to 0.1529 in 2015. In the last 25 years, the moderate ecological risk level covered the largest area of the study region; the higher ecological risk level was mainly distributed in the cultivated land of the southwestern region and the waters of the western region of the study area, and its area decreased. Grade reduction zones of ecological risk were mainly concentrated in the higher ecological risk area, moderate ecological risk area, and lower ecological risk area. Meanwhile, grade increase zones of ecological risk were mainly concentrated in the lower ecological risk area and moderate ecological risk area, that is, the grassland and waters of the eastern region of the study area and the cultivated land of the southwestern region. The rapid development of the port industry and new coastal town resulted in the intensification of land use change, which damaged the balance of the ecosystems. The overall spatial difference of ecological risk in the study area had increased, showing the high-high aggregation and low-low aggregation in the local area. The area of high value primarily aggregated gathered south along the western boundary of the study area, and the low value aggregation region was largely distributed in the northeast of the study area and the eastern coastal areas. In addition, arable land, waterbodies, and construction land were the main sources of ecological risk in the study area. The results of the present study could provide a scientific theoretical basis and reliable technical support for the realization of land sustainable utilization, promoting the coordinated development of land use and environment protection, and the policy making of ecological risk management.