| With the rapid development of global economy, the progress of technology and the dramatic increase in population, the global ecological environment is under increasing pressure. Since the1990s, the global environment change research became one of the most remarkable environmental and scientific propositions in the academic circles. Landscape is the carrier of human social activities; all of human social and economic activities are conducted in landscape area. The formation of the landscape is the result of natural and artificial management of patch mosaics. Human activity is the main motivation of landscape change and leading to the current ecological crisis. Land use/land cover change (LUCC) is one of the main cause and component of global environmental change, causes many change of natural phenomena and ecological processes, land use/land cover change research has an important significance to understand of the regional ecological environment and global climate change. Therefore, carrying out the land use/land cover, landscape dynamic and landscape scale effect research in multidisciplinary, quantitative analysis of the relationship between landscape pattern and the influence factor to reveal the driving mechanism of landscape pattern have an important theoretical and practical significance.Taking guanzhong-tianshui economic zone as the research object, using TM, ETM satellite image interpretation of remote sensing image of1980,2000and2010, get the landscape type map, analysis the land resources and land use change process of each period to reveal the land use temporal and spatial variation characteristics of guanzhong-tianshui economic zone. In addition, this paper tries to reveal the scale effect of the landscape pattern from two aspects response of landscape index granularity and amplitude change, and then determines the optimum research granularity of guanzhong-tianshui economic zone, laid the data foundation for selecting suitable scale of landscape dynamic change, and have space-time dynamic analysis of the landscape pattern under the support of Fragstats. Finally, combined with relevant nature, the humanities characteristics, analyze and simulate the landscape pattern index correlation reveals the driving force factor, driving process, and driving mechanism of landscape pattern. Main conclusions are as follows: (1) Cultivated land, grassland, water area and unused area is reduced, and forest land, construction land is increased in guanzhong-tianshui economic zone from1980to2010. Cultivated land decreased93791.5hm2, with an average annual increase of3126.384hm2, rate of0.087%. Construction land decreased74651.04hm2, with an average annual increase of2488.368hm2, rate of2.320%, is the biggest compared to other types of land use. Overall, the construction land has the biggest change rate, growth rate, rapid growth of land in guanzhong-tianshui economic zone mainly express in xi "an construction land expansion.1980,2000and2010, land use structure keeps stable, cultivated land, grassland, forest land are the main landscape types. And the rank of land use area is cultivated land> grassland> forest land> construction land> water area> unused land. From the point of regional differences, reciprocal transformation occurs between various landuse types in guanzhong-tianshui economic zone from1980to2010. The gravity center of the various landuse types, excepting arable land,transfer different degrees.The land use type which drift the bigges degree is grass, and drift distance is32.331km.Within the county unit, different types of land has different change dynamic degree, which explains that due to different natural factors and human factors, the conversion of land use types exist obvious regional differences.(2) On type level landscape pattern time-space dynamic of landscape pattern results showed that area percentage and numbers of patches of cultivated land, grassland, water area, unused land are declining while forest land, construction land are on the rise in guanzhong-tianshui economic zone from1980to2010. The largest patches index of cultivated land, grassland and unused land is on the decline while the forest land, water area, construction land has increased. Landscape shape index of forest land, grassland, water area is on the decline, while the cultivated land, construction land and unused land is on the rise. Average number of dimension of cultivated land, forest land, construction land is on the decline, while grassland, water area and unused land are on the rise. The connection index of cultivated land, forest land, grassland and unused land is on the decline, while the water and the land for construction is on the rise. Look from the landscape level, from1980to2010, numbers of patches, average patch dimension, connection index is on the decline. And landscape shape index, shannon diversity index and shannon evenness index is on the rise in guanzhong-tianshui economic zone. Artificial interference to landscape pattern gradually increase, shape of landscape patch tends to simple, rules, landscape physical connectivity is reduced, the landscape trend to uniformity and stability.(3) Landscape index can indicate scale effect of changes in granularity and amplitude. Landscape pattern index has a sensitive response of granularity and amplitude at the type level and landscape level in guanzhong-tianshui economic zone. With landscape types, different landscape pattern index has the following4types of trends:1) Index value basically remain unchanged2) Index value present regular rising or falling, have obvious turning point3) Index value present regular rising or falling, but the turning point is not obvious4) Index change irregularly, and appeared many turning point. With landscape level, landscape index changing with granularity also presents four trends:1) Index value present regular rising or falling, have obvious turning point2) Index value present regular rising or falling, but has no turning point3) Index value present regular rising or falling, but the turning point is not obvious4) Index change irregularly, and appeared many turning point. Parts of the landscape index can respectively fitting with cubic function, quadratic function and linear function with granularity curve; The suitable granularity range of various landscape type landscape index calculation in guanzhong-tianshui economic zone are:cultivated land120m, forestland120-160m, grassland90-130m, waters area90-110m, construction land90-130m, unused land110-160m. The suitable granularity of landscape pattern in guanzhong-tianshui is120m.(4) According to research on spatial autocorrelation of landscape pattern, there exits spatial correlation between the landscape pattern in guanzhong-tianshui economic zone. Landscape pattern affected by natural factors and human factors. Uses the classics regression model and the space regression model carries on the landscape pattern and the influencing factor relations quantitative analysis. The result indicated that the space regression model simulation precision surpasses the classics regression model; the visual impact of the factors of land from each other. |
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