Evolution Of Driving Mechanism On The Changes Of Agricultural Land In Wuxi Region

Agricultural land is one of the most important types of land use and as the essence of land resources, it is the basis of national economic development, the security of social stability and the premise of sustainable development of ecological environment. Currently, with the growth of world population and development of urbanization, agricultural land area in China is declining rapidly. As China has the highest population in the world, the decline in agricultural land area will bring far-reaching impacts on land resource security. Therefore, it is significant for reasonable planning and utilization agricultural land and effectively protecting farmland to gather the information of agricultural land resources and understand the change process of agricultural land in regional development.In the landscape process of land use change, due to differences in policy, population, economy, terrain conditions, there are some regional differences and phase differences in the driving mechanism. Domestic and international research on land use change and its driving mechanism is mostly focused on the temporal dynamics of land use change and analysis of the specific driving factors. But spatial differences in the regional ecological processes and relative effects strength change of all kinds of driving mechanism in the different stages of economic development were less studied, still to be further research.Wuxi City located in the Yantze River Delta, which has dense settlements and developed agriculture in eastern China. As an important food-growing region, the area has a temperate climate, its agricultural land has a high quantity and quality. Due to favorable geographical location and powerful economic basis, the agricultural land had declined rapidly. The thesis chooses Wuxi as the sample for the dynamic of agricultural land, which, the author believes, will shed light on the agricultural land use change of the entire Delta and the country as a whole.To reveal the spatiotemporal variations of the driving factors of agricultural land reduction hotspots (ALRHs), the changes in agricultural lands and the driving mechanisms in the Wuxi region were studied using multi-temporal Landsat TM data. The results showed that:(1) The agricultural lands in the study area decreased continuously from1995to2010. The reduction rate of agricultural lands was different:the fastest is Wuxi district, followed by Jiangyin City, Yixing City was significantly slower than the former two. The main agricultural land converted into construction lands, partly into water; This region urbanization process of overall performance for the occupation of the agricultural land and construction land expansion.(2) The ALRHs tended to be adjacent to the major cities and towns; and their spatial pattern can be characterized by three distinct transitional phases, i.e., scattered distribution (1995-2001), relative concentration distribution (2001-2005) and more decentralized distribution (2005-2010).(3) Accessibility factors presented highly consistent effects on ALRHs across the study period. The reduction rate of agricultural lands was enhanced with increasing accessibility. Socioeconomic factors had strong influences on ALRHs, but their correlations with the ALRHs showed apparent spatial and temporal variations. In contrast, physical factors such as topography had relatively weak influences on ALRHs, but their effects were relatively significant across different landscape locations and study periods.(4) The primary driving forces of ALRHs in the Wuxi region changed from physical and geographical factors (e.g. accessibility and topography) to socioeconomic factors (e.g. industrial productivity and per capita income). Along with the landscape ontogenesis, socioeconomic factors played a more and more important role in agricultural land change.Overall, this thesis studied the changes in agricultural lands and the driving mechanisms in the Wuxi region, found the dynamic change of the distribution of the ALRHs; while revealed the spatiotemporal variations of the driving factors of agricultural land reduction hotspots. The results could provide a reference for protection on agricultural land and ecological environment.