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Under the background of rapid urbanization, promoting high-quality land use transformation is an important way to achieve sustainable and coordinated development of regions. The transformation of regional land use function is the inevitable result of rapid urbanization and one of the important characteristics of regional spatial function transformation and reconstruction. This study was based on the district and county scale and the dominant function of land use, and used synthetically index method, coupled coordination degree model, and geographically and temporally weighted regression model (GTWR). This paper analyzes the spatio-temporal evolution track and spatial equilibrium state of land use function transformation in the urban agglomeration around Poyang Lake under a long time series, divides the transition stage of each county and region, and reveals the driving mechanism of land use function transformation. The results show that: 1) From the perspective of temporal changes, the land use function index of the urban agglomeration around Poyang Lake increased from 0.20 to 0.55 during 2000-2020, with continuous optimization and improvement, but it was still at a medium and low level in general, showing staged characteristics and experiencing a development process of slow developm-rapid increase and slow growth. From the perspective of spatial distribution characteristics, the functional index gradually presents a spatial distribution pattern of high in the east and west, low in the east, showing a significant spatial difference. 2) The index of coordination degree of production-life -ecological function and production-life function continued to rise, while the other coupling degree and coordination degree index showed a trend of fluctuating development. The production-life function showed a low level and high coupling phenomenon from 2000 to 2010, and the life and ecological function lagged behind the development of production function from 2010 to 2015. The coupling coordination index showed a spatial distribution pattern of high in central and southwest, low in northeast and northwest, and the gap between regions and counties widened. The overall transformation is mainly low-quality, with the average number of districts and counties accounting for about 50%, but the number of districts and counties in the transition period and high-quality transformation has increased, and the quality of functional transformation has improved. The quality of land use function transformation in the central and western regions is obviously better than that in the northern and eastern regions. The high-quality transformation regions are mainly located along the Chang-jiu Economic Corridor and Xinyiping city cluster, while the eastern and northern regions are mostly low-quality transformation. 3) There are significant spatial differences in the driving effects of different influence factors. The positive driving effect of population density and urbanization level continued to increase, the negative driving effect of the proportion of secondary and tertiary industries increased, and the influence of per capita GDP, per capita fixed asset investment and per capita grain output tended to weaken. The Poyang Lake city cluster should implement differentiated development policies according to the transition stage of land use function of each district and county, make up for the development shortcomings of district and county, and enhance the coupling and coordination degree of functional systems. The research results can provide reference and decision-making basis for improving regional land use efficiency and promoting multi-functional cooperative development of land use. [ABSTRACT FROM AUTHOR]

Land use/cover change caused by urbanization and industrialization had changed the function of land. In order to explore the evolution law of regional land function, taking Huanghua city, Hebei province as the research area, this paper first classified the land function and analyzed the spatial distribution characteristics and law of land function in 2008-2014 using geographic information system(GIS) and remote sensing(RS) data, and then the biological production function and the value of the ecological environment function were calculated using production capacity accounting model and net primary productivity model to reveal the evolution process of land function value. In the course of land function classification, based on the tree classification method, the two-level classification systems were adopted. According to the main function of land and the difference of land use pattern, the research area was divided into 6 functional categories and 21 functional subcategories. In order to show the result of land function classification, fully reflect the relationship between the various land functions within the region and reflect the land function type, combination and distribution law of the study area, the land distribution maps of Huanghua city in 2008 and 2014 were drawn respectively taking the leading principle as the basic principle. Then it output the function information in graphic mode. It could be seen through the comparison, the functional area of the biological production in the land function category increased most. It totally increased by 3648.8 hm2. It showed that in recent years Huanghua city used land development and consolidation, brick kiln reclamation, fertilization and irrigation, and salt and alkali elimination method. The other functions had improved. It had the ability to provide people with agricultural products. The land area of land biological production was significantly increased. The land area of the ecological environment function was reduced by 8238.3 hm2. In recent years, with the rapid development of regional economy, a large number of ecological and environmental function land changed to other functional land use, especially the tidal flat wetland and water area(a total change area of 6246 hm2), and the land with biological production function(3622.1hm2). The salt field was transformed to raw material supply function by 2124.96 hm2. Most of the rest was converted to the load bearing function. Load bearing capacity of the land area had increased by 2265.6 hm2. This paper took the biological production function and ecological environment function as an example. The change of function value was analyzed. Production capacity of agricultural land represented the size of the functional value of biological production. Main idea was that in the first place the crop yield per unit area and the corresponding agricultural land use index were established. Then the agricultural land classification unit use indices were substituted into the corresponding function equation. It could be calculated to achieve their yield per unit area. The classification unit of agricultural land could realize that the value of land biological production function was calculated from the yield per unit area yield multiplied by the corresponding area. Ecological service value represented ecological environment function. The value of ecosystem services was based on the spatial and meteorological data. Combining with the investigation of foreign trade, the net primary productivity and other models could calculate. By comparing the value of the function, it showed that the biological production function of cultivated lands and fields had been generally improved from 2008 to 2014; Except the unchanged "the other lands’ ecological environment function", the function values of other sub-functions decreased to different extents. The results could provide scientific basis for land function evaluation, ecological red line delineation and land use planning. [ABSTRACT FROM AUTHOR]