Research Of Urban Spatial Expansion And Driving Mechanismbased On DMSP/OLS Data

Since the reform and open to the world in late 1970s, China’s economic develop-pment and rapid urbanization have accelerated remarkably.However, regional society,economic growth and environment protection express obviously imbalance, which ur-gently calls for a detailedand comprehensive insight of the spatial and temporal varia-tion of urban expansion, to get a well understanding the imbalance and to provide scie-ntific basis for formulating the regional sustainable development decision.Moreover, there is a big difficulty using conventional method to obtain large scale urban spatial expansion data. Alternatively, using night light image data helps provide an effective support for the study of large scale urban expansion.In this paper, by using RS,GIS and statistical analysis, we extracted the DMSP-/OLS data of Guangxi during 1998-2010, monitoring 89 counties’urban spatial expa-nsion in Guangxi, extended spatial and temporal characteristics, analysis of Guangxi city spatial expansion direction, strength and process development and utilization the driving force factors and mechanism, and combining the method of statistical analysis of Guangxi city down space expansion.This research mainly draws the following conclusions:(1)From the view of temporal characteristicsthere is obvious increasing of urban expansion inGuangxi from 1998 to 2010, and shows an accelerated trend. The area of urban land in Guangxi increasedby 4192.76km2 during this period.The urban extent i-ncreased by 1244.32 km2 from 1998 to 2004, and itincreased by 2948.44 km2from2004 to 2010.The area of urban land in all cities of Guangxi increased in different de-grees. The area of urban land has increased in varying degree.The expansion area of urban land in Nanning was first reached 885.20km from 1998 to 2010,following Liu-zhou was 474.90km2.(2) From the view of spatial characteristics, after 2004, Guangxi night light gath-ering area exhibits a typical point and axis spread diffusion characteristics, especially the ①Baise-Tianyang-Tiandong-Pingguo-Longan-Nanning②Pingxiang-Longzhou-Ningming-Chongzuo-Fusui-Nanning,③Du’an Yao-Dahua Yao-Mashan-Wuming-Nanning,④Tian’e-Nandan-Hechi-Yizhou-Luocheng Mu-lao-Liucheng -Liuzhou, ⑤Nanning-Binyang-Liujiang-Liuzhou, ⑥ongxing-Fangchenggang-Qinzhou-Hepu-Beihai, ⑦Nanning-Hengxian-Lingshan-Pu-bei, Bobai-Yulin-Rongxian-Cenxi,⑧Wuzhou-Cangwu-Tengxian-Pingnan -Guigang-Guiping,⑨Lingui-Guilin-Lingchuan-Xingan-Quanzhou, ⑩-Lipu-Yangshuo-Pingle-Zijin-Hezhou.(3) From the view of driving forces of urban spatial expansion, the integrated eff-ects of natural and social economic conditions are driving the urban space expansion of Guangxi. Although the natural conditions is a prerequisite construction, urban popu-lation scale and economic growth perform a very strong correlation with urban spatial expansion. Therefore, the social and economic factors are the mainly driving factors of urban spatial expansion.