Analysis On Land Use Change And Its Driving Forces In The Yellow River Delta

Research on land use change is the frontier and a hot issue in the global change research, and research on regional land use change and its driving forcess is one of the most important parts. Taking Yellow River Delta as the study area, in this paper, the author firstly expounds the research background, significance, content and the home and abroad developmental trend, and then makes a introduction to the natural and socio-economic conditions in the study area. Supported by the remote sensing (RS) and geographical information system (GIS) and based on remote sensing data of 1986, 1996, 2001and land use survey statistics of 2004, the author calculated total land use changes, dynamic, utilized composite index and reclamation and utilization rate, and analyzed spatial and temporal characteristics of the Yellow River Delta in 1986-2004. And combined with the natural and socio-economic factors, gray association was adopted to analyze the land use driving forces. The analysis results show that the land use change is obvious.In terms of research period, from 1996 to 2004, cultivated land, grassland and unused land decreased while woodland, construction land, residential land and waters increased in the Yellow River Delta. The greatest change in area is in waters, followed by unused land, grassland, residential land, farmland, woodland and urban construction site, while the greatest change in rate order is in waters, followed by woodland, residential land, unused land, urban construction land, grassland, farmland. During the research period, the annual average change of land use degree in Yellow River Delta is 0.75%,Re>0, which indicates that the land in this area is in the period of development and the utilization degree of land is increasing steadily. The most violent change is from 1996 to 2001, 1.42% per year.In terms of research area, land use composite index of Dongyingqu, Guangraoxian and Lijinxian in southwest region is higher by 85.5%, compared to that of Hekouqu and Kenlixian in northeast region. At the same time, used land planting rate and utilization rate in the former three areas are higher than the latter two. This shows that southern region of the Yellow River Delta is more developed than northern region, with higher land use degree and more changes of land use types. Land-use change becomes more intense from north to south, from the coastal areas to inland.The driving factors of land use change in the Yellow River Delta includ nature factors and socio-economy factors. Natural aspects mainly include three parts----Yellow River dying-up, seawater intrusion and dry climate. As population increases and economics develop, socio-economic factors such as population, economics and policies are playing an increasingly important role in land use change. By gay association analysis of the three natural factors and eight social factors from 1986 to 2004, it can be concluded that population (including proportion of the agricultural population) and agricultural structure (i.e. proportion of forest, farming, and fishing in gross agricultural output) are considered as the main driving forces for land use change in the Yellow River Delta. Among these factors, population is the most influential one relating to change of farmland area, and the following factors are agriculture population and the proportion of forest, farming and fishing in gross agricultural output. Population increase and its structure change are taken as the main driving forces for grassland, construction land, residential land and unused land. The proportion of forest, farming, and fishing in gross agricultural output is taken as the main driving force for woodland and waters and population and such natural factors as climate and rainfall also relate to its change.