兰州市市区景观生态格局特征分析

Analysis of urban landscape pattern characteristics of Lanzhou

基于景观生态学理论,利用兰州市市区遥感影像数据和Fragstats软件,在GIS技术支持下,综合选取多样性、破碎度、均匀度、优势度、分离度等景观格局指数,从斑块格局、区域景观格局等方面进行景观生态研究.结果表明:兰州市市区林草地占总面积的45%,构成区域景观的基质;区域内景观多样性分布具有较好的空间结构,多样性指数城关区最高为1.447,均匀度七里河区最高为0.811;区域中人工景观斑块形状规则,分布均匀,自然景观分维数较高,其中荒草地分维数1.443;受人为影响,农业景观类型破碎度较高,大量耕地转变为建设用地和林地;城市人均绿地9.47m2,但绿地斑块分布散乱,生态效益低;各类型绿地斑块之间缺少较好的生态廊道,格局连接性较低;分离度城关区为0.015、七里河区为0.045、西固区0.037、安宁区为0.021.

Based on the theory of landscape ecology,the diversity,fragmentation,evenness,dominance,separation of landscape indices,plaque pattern,regional landscape structure were researched with remote sensing image data of Lanzhou and Fragstats software.The results showed that 45% of the total area of Lanzhou was forest and grassland to constitute the matrix of the regional landscape.The distribution of the regional landscape diversity with better spatial structure.The diversity index of Chengguan District was the highest,evenness index of Qilihe area 0.811 was the highest.Artificial landscape patch shape rules in the area and natural landscape fractal dimension was higher than others,grassland sub-dimension was 1.443.Agricultural landscape type had higher fragmentation,most of fields changed to construction areas and forestry.Urban green space 9.47 m2 per capita,but the green patch distribution was scattered and eco-efficiency was low,lack of good ecological corridor between the various types of green patch,the pattern of low connectivity.Separate index was 0.015 in Chengguan,0.045 in Qilihe,0.037 in Xigu and 0.021 in Anning.