Research On Urban Sprawl Of Zhengzhou City And Its Driving Forces Based On GIS&RS

Both International Geosphere-Biosphere Program (IGBP) and International Human Dimensions Program on Global Environmental Change (IHDP) put forward"the Land Use/Land Cover Change"(LUCC) program in 1995. The urban land is teemed with the most interesting and complicated human activities, and with the aggressive progress of urbanization, the land of cities expands sharply, which has great impact on the urban development and also degrades the regional ecological environment wherein. All of the above explains why the urban sprawl is being more and more concerned and researched as a hotspot up to date. Besides, the land intended for building construction and the cities'developing dimensions should be regulated properly, so it's inevitable and indispensable that the urban sprawl be monitored dynamically. Thanks to the technologies of both Remote Sensing (RS) and Geographical Information System (GIS), the new advanced dynamic monitoring of urban sprawl is endowed with much more supreme virtues than its traditional counterparts.Reviewing the urban-sprawl-related researches, it focus on the urban sprawl of Zhengzhou City, capital of He'nan province, China, to do our case study with that new method. The data here are three Remote Sensing images, which are shot on 11 Mar 1988, 16 Oct 1992 and 2 Sep 2002. The paper first focuses on the dynamic change of the urban regions of Zhengzhou City, then try to analyze the driving forces underlying the expansion. It includes:(1)Researching on extracting the information of the urban sprawl. In this part,three methods: the supervised classification based on the Maximum likelihood method, NDBI method, and Neural Network Algorithm,are compared rigorously as to their precision of extracting the essence information.(2)Focusing on the temporal and spatial changes in the process of the urban sprawl. In this section, the speed and dimensions of Zhengzhou City's urban sprawl is analyzed, with the help of the analyzing functions in GIS software, in the hope to summarize the dynamic change of the land use of Zhengzhou City during the last 15 years.(3)Dedicating to discovering the driving forces underlying the urban sprawl. 4 major factors and 12 social-economical sub-factors are selected including demographic, economic, of citizen's life, and of transportation ones, which are processed with Principal component analysis, stepwise regression analysis to make clear the driving mechanism of Zhengzhou's urban sprawl.At last, conclusions are drawn as follows:(1)When extracting the information on the urban sprawl, 3 methods are employed to have a comparative analysis on verifying which one works better. Finally the supervised classification is proved to be the best with its total precision as high as 88.80% and Kappa parameter as 0.8559.(2)Since 1988 through 2002, the geometrical center of Zhengzhou City first locates southeast and then shifts due east, which is also consistent with its dynamic urban expansion.(3)With the rapid development of economy and swift urbanization, the land planed for construction surges sharply, and it varies its unique characteristics on different stages for each individual region.(4)From the analysis above, it comes to the conclusions that the main driving forces which claims the urban expansion are from economy, transportation, and population.