上海城市景观生态格局演变与生态网络结构优化分析

为了优化上海城市生态网络结构,综合应用景观格局、景观格局指数以及景观生态网络分析方法,提出上海城市生态品质提升途径。首先,应用面向对象的遥感图像分类方法获得了2008年和2015年上海市建设用地、农业用地、水域和绿地等景观类型分布,应用Fragstats软件获得景观格局指数,比较了城市景观格局和景观格局指数的演变;其次应用最小成本路径方法构建城市生态网络,与城市道路交通网络叠置,确定了生态网络结构的间断点;最后与《上海市基本生态网络规划》比较,提出了城市生态网络发展建议。本研究获得如下结论:(1)2008～2015年,上海市建设用地、农业用地、绿地和水域的面积比例由38∶51∶5∶6演变为46∶39∶7∶8。(2)上海市景观格局日趋破碎化、复杂化,连通性下降;建设用地的优势景观类型地位强化,郊区建设用地呈现破碎化入侵,农业用地面积减少且破碎化;绿地系统面积增大,但连通性不足,结构待优化。(3)经最小阻力分析获得上海市105条潜在生态廊道线路,在浦东新区、奉贤区、金山区、松江区和青浦区具有较好的环状度;经叠置分析识别出上海市骨干生态廊道的62个间断点,主要分布在青浦区、松江区、浦东新区以及奉贤区。(4)经比较分析发现,城市生态网络规划的生态网络骨架基本保持,但局部的生态网络结构存在问题,上海西北部和北部的生态廊道空间萎缩,东南部生态空间出现碎片化。

Analysis of Landscape Ecological Pattern Evolution and Ecological Network Structure Optimization for Shanghai

In order to optimize urban ecological network structure of Shanghai city, some ways to improve urban ecological quality are proposed incorporating landscape pattern, landscape pattern index and landscape ecological network analysis. First, landscape types such as construction land, agricultural land, water area and green land during 2008 and 2015 was obtained by using object-oriented remote sensing image classification method, and the landscape pattern index are calculated using Fragstats software. The evolution of urban landscape pattern and landscape pattern index in the above two years were compared and analyzed. Then, the least cost path method is used to develop the urban ecological network and overlap analysis between the ecological network and the urban road network is used to determine the break points of the ecological network structure. Finally, compared with the plan of Shanghai Basic Ecological Network Planning, the suggestions for the future development of the urban ecological network are put forward. The conclusions are as follows: (1) The proportion of Shanghai construction land, agricultural land, green land and water area changed from 38:51:5:6 to 46:39:7:8. (2) The landscape pattern of Shanghai is becoming fragmented and complicated, and the connectivity is declining; the dominant landscape type of construction land is strengthened; the suburban construction land is fragmented; the agricultural land is reduced and fragmented; the green land is enlarged, but the connectivity is insufficient, and the structure needs to be optimized. (3) 105 potential eco-corridor lines in Shanghai were obtained by the least resistance analysis, which had better circularity in Pudong New District, Fengxian District, Jinshan District, Songjiang District and Qingpu District, and 62 break points of the main eco-corridor in Shanghai were identified by overlay analysis, mainly distributed in Qingpu District, Songjiang District, Pudong New District and Fengxian District. (4) Through comparative analysis, it is found that the framework of the ecological network of Shanghai Basic Ecological Network Planning has basically been maintained, but the local ecological network structure is facing problems. The space of the ecological corridors in the northwest and north of Shanghai is shrinking, and the ecological space in the southeast is fragmented.