中文摘要：

选择干旱河谷型城市兰州市作为研究对象,应用RS和GIS技术,对1985,1995,2000和2007年景观生态格局进行定量分析;利用熵值法综合评价了不同景观类型的结构和功能对于区域生态功能流的影响;以累积耗费距离面、生态源地、耗费路径为依据,构建源地、生态廊道和生态节点等景观组分优化景观格局;利用dIIC和dPC指标对景观关键区的贡献值进行了评价.结果表明,兰州市景观生态功能强度空间差异性显著,影响区域景观生态过程和功能;河流谷地或者河流交汇处等关键区域对景观连通性和生态流重要值最大,景观连通性受到显著影响,是景观生态节点优化的首要对象;加强保护核心斑块源地,提高景观连通度是实现景观格局优化的关键.

英文摘要：

Lanzhou City is chosen as a study area and the technologies of remote sensing（RS）and geographical information system（GIS） is applied,and meanwhile the priority is been given to understanding of the spatial-temporal characteristics of landscape pattern change through visually interpreting landsat TM images of 1985,1995,2000 and 2007 respectively.Entropy method is used to evaluate the effects that the constructions and functions of different landscape types imposed to the urban ecological functional flow.Based on an accumulative cost intensity model,the calculation of the cost intensity,and the sources identification,the critical ecological positions,corridors,and sources are designed in the study area,and the landscape pattern optimization is further discussed.Results indicate that ecological process and functions of landscape in Lanzhou City are different in spatial distribution.The critical ecological positions for connectivity of landscape near the river area and river interchange area,which is the first primary object to be optimized.The optimized landscape pattern for Lanzhou City is to strengthen protection of nature resources,maintain high landscape connectivity,and promote the sustainable development in land use and environmental protection.