Optimization of ecological landscape patterns based on RS and GIS:a case study of Lanzhou City

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.