Abstract: The landscape ecological pattern of urban land-use expansion in Liangzhou District of Wuwei City, Gansu from 1985 to 2015 was analyzed by circle analysis, landscape index andurban expansion intensity index, with land-use status data in 1985, 1995, 2005 and 2015 in ArcGIS 10.2 and Fragstats 4.2. The whole study area was divided into four directions, i.e., northeast (NE), southeast (SE), southwest (SW) and northwest (NW). Each direction was divided into 23 concentric circles of 3 km incrementing radius to analyze the spatiotemporal evolution characteristics of urban spatial expansion and the land use and landscape pattern changes during this process. The results showed that the urban construction land of Liangzhou District was mainly distributed within 3 km of economic center. The area of urban construction land continuously increased from 1985 to 2015. The east and southeast were the main directions of urban expansion. The shape of landscape patch for urban construction land was simple. With the disturbance of human activities, the number of patches was increasing and the fragmentation was intensified. The aggregation of patches was higher when they were closer to the urban economic center.

Key words: stable carbon isotope, karst seasonal rain forest, habitat type., water use efficiency