Lanzhou urban growth prediction based on Cellular Automata

Lanzhou City, the capital city of Gansu Province and located in the geometric center of China's land territory, is a typical narrow zonal valley city in the west of China with the Yellow River going through it. It is also an industrial city with many large petroleum and chemical industries. Lanzhou is one of the important traffic hubs and freight transfer stations in northwestern China. The development of Lanzhou City is severely restricted by surrounding mountains so facing a series of problems such as environment pollution, traffic jam, unreasonable land use and sustainability. So, it is necessary to make urban expansion prediction to provide references for the urban planning department of this city. SLEUTH is kind of Model applies self-adaption Cellular Automata to model the urban expansion and land use, and it has been successfully used in predicting the growth of many metropolises all over the world. Taking remote sensing image such as MSS, TM, ETM and CCD as the main data sources and along with the maps of urban planning, topographic and socio-economic statistical, the spatial and attribute database of the study area was built firstly. Then the SLEUTH model was applied to rebuild the sprawl process and predicting the urban expansion in the future. The results show the Urban Area Index had a linearly increasing trend from 2007 to 2025 and the pixel number will increase from 145718 to 178560. Urban Edges Index will grow nonlinearly and the pixel number will increase from 6250.31 to 178560. Urban Cluster Index will increase rapidly from 236.21 to 394.07 by 2013, and then it will stabilize. The Mean Urban Cluster Index will gradually reduce to a stable status by 2013. The analyses indicate that the remaining land in Lanzhou for urban expansion is quite limited; urban expansion is mostly influenced by road and traffic situation; slope is a major limitation for urban expansion. In the future, for the development of Lanzhou, it need to strengthen and accelerate the construction of central city area, move administrative organizations out of the centre area, strengthen the modernization of urban traffic, support the development of minor towns around the city so they can share part of responsibilities of metropolitan Lanzhou City.