| Mountain is a special ecological environment type of terrestrial ecosystem and its resources have an important role for maintaining global ecological balance and human existence and development. Landscape Ecology concerned about the landscape scale, pattern, process and heterogeneity characteristics. For the vulnerability and complexity of mountain eco-environment as well as it is easily influenced by human activities. Studying mountain landscape pattern, landscape function, landscape dynamic change by principals of landscape ecology has important significance for regional macro planning and eco-environmental Construction.Qinling are important mountains in China. At present, some scholars have done studies on changes of landscape pattern in the Qinling Mountains, but studies on relations between the terrain and the landscape pattern changes are also quite few based on Digital Elevation Model. There are massive research work to be done.This paper selected the upper Changan River in Ningshan County as study area. Based on field investigation, DEM was created and terrain information was obtained by using topographic maps and GIS software. Then by remote sensing interpretation and building GIS spatial database, landscape distribution maps and the corresponding attribute data were geted. Relations between terrain and landscape pattern changes is analysised. Finally, landscape ecology evaluation system was combined and the changes of landscape pattern was studied quantitatively and qualitatively in research area.Through this research, draw the following conclusions:(1) Through analyzing the changes of structure and area of first-class and second-class landscape, foundings show that in the past ten years, the main character of landscape pattern changes is natural secondary forest land and dry land reduced but human effect forest land and waste-grassland expanded in research area. The results show that human disturbance effect enhanced in the upper Changan River which resulting in the natural landscape reduced significantly, but the operating landscape increased significantly. Artificial landscape had no obvious change, which show the limitations of development of towns and roads in the mountain area and its urbanization is still low.(2) Analyzing the characteristics of landscape pattern based on terrain factors including elevation, slope and aspect founding that landscape pattern changes have certain correlation with terrain.①Studying changes of landscape pattern based on different elevations founding that land use degree is higher in low altitude region and human effect factor is stronger while human effect factor is weaker in high altitude region.②Studying changes of landscape pattern based on different slopes founding that artificial landscapes distributed mainly on the gentle slope and forestlands distributed mainly on the steep slopes more than 25°. Dryland and waste-grassland distributed much broader. The results showed that the steeper the slope is, the weaker the effect of human activities. Steep slop above 25°had returned farmland completely.③Analyzing changes of landscape pattern based on different aspects founding that most landscape types distributed on half-sunny slope and sunny slope in research area which suggested land use capability is higher on these two aspects.(3) Analyzing by landscape evaluation indexes founding that:①Studing from patch types level, in the past 10 years, the total number of patches increased obviously. Fractal dimension of human effect forest land, waste-grass land and highway land is higher and their patch shape is very complex. Fractal dimension of other landscapes is lower and with simple patch shape. In the last ten years, patch shapes of human effect forest land tended to be simplifier while waste-grass land changed in the contrary. Patch density, degree of fragmentation and splitting indexes all can reflect the degree of fragmentation. The landscape degree of fragmentation had increased in entire research area. Dry land, human effect forest land and waste-grass land increased obviously.②Analyzing from landscape-level, during 1994 to 2003, landscape diversity increased meanwhile evenness increased relatively and dominance reduced obviously. These showed that the landscape's heterogeneity increased. The landscape deviation increased obviously which indicated the land utilization degree enhanced.(4) Analyzing the problems existed in landscape ecology and landscape structure and their environment effect finding that: Different landscape types and their spatial pattern have different influences to environmental effect such as runoff, erosion and so on. The eco-environment of natural secondary forest landscape is good and soil erosion degree is little. human effect forest land is unstable and is easy to cause soil erosion. The most unstable landscape is waste-grass land with single structure and poor ecological environment. Landscape optimization and ecological restoration measures were proposed in view of these problems.(5) The "3S" technology is the main technical means in this paper. This research breakthroughed studying landscape pattern only from horizontal direction in tradition and studied landscape changes from spatial vertical for nearly ten years with topographical maps. It reflected human impacts on vertical gradient changes of landscape. |
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