| Landscape ecology focus on the temporal and spacial landscape pattern, and the relation between the pattern and its process. Using theory of the landscape ecology to research landscape pattern of mountain region, landscape function, landscape dynamic change, land use and landscape ecological environment of mountain area, etc. have theory and practice significance for the environmental construction of the fragile district. In our country, the research of the landscape of mountain region is relatively lacking. A lot of questions still remain to study further.Qinling Mountains is an important mountain area in our country. It should be that the ecological environment is good under the natural state, and it also has abundant living resources. However, the regional ecology has been degraded and destroyed seriously because people was impercipient about the ecological characteristic and ecology service function, and made an unreasonable development and utilization to the natural resources.The Chang'An river Valley of Ningshan County was selected as typical study area in the paper. On the basis of studying the land cover in mountain region, RS image analysis, investigation in the field (uses GPS technology) and the test of soil, the landscape type of the Chang'An river valley was graded into three classes. Under the landscape ecology appraising analysis system, image interpretation in supervised classification way, and GIS space database analysis, the ration and qualitative comprehensive appraisal on the landscape pattern change were deeply analyzed. The interrelated conclusions were elaborated as follows:1. According to the principle of landscape classification, the whole valley landscape was divided into three-class types. With the change of research scale, every type adopts different dominant elements. And there is a certain interrelation between each class of type. It made up of a relatively scientific and systematic landscape pattern system.2. Under analysis of the change of the class I landscapes area and structure, the paper got that the Chang'An River valley have been interrupted frequently by people, and influenced seriously during the late ten years. Froml994 to 1999, the naturallandscapes reduced greatly and the area of operating landscapes had been increased by more than twice. Since 1999, the natural landscapes of the Chang'An River valley have been developed to some extent and the out-of-order developments of the operating landscapes have been controlled. The landscape structure is more reasonable for mountain area, which is based on natural landscapes as matrix, with developing operating landscape patch properly. And it can exploit local resources moderately, while protecting the good original ecological environment and forming good circulation.There is no change in the artificial landscape area during the late ten years. It showed that the development of the town-build in mountain area is localized.3. By analyzing the spatial character of the class II landscape, it found that the land cover has been changed evidently in recent ten years. Firstly the number of landscape patch increases obviously, mainly including the natural secondary forest, artificial woodland and grassland. The number of patch of the irrigated-paddy-field and dry land landscape was increasing from 1994 to 1999, but decreased from 1999 to 2003. There are few changes in the river area, road area and town-residence area. The average area of the town residence patch and the river patch are the biggest ones because of the continuous distributing. And that of the grassland and dry land was smallest because of people influence.Secondly, compared with the late ten-year landscape of the Chang'An River valley, it discovered the natural secondary forest is main type. The fractal dimension of grassland was higher than other landscape types. And the fragmentation index of the study area has increased greatly.Finally, by the integrated analysis of the degree of land use, it found that the landscape deviation index of the Chang'An River increased greatly from 1994 to 1999, and decreased from 1999 to 2003.4. Made sample plot to research the individual landscape types in the class III, it discovered that the natural secondary forest is the most stable landscape type in ecological environment. The artificial-influence forestland has worsened tendency. The grassland is the most unstable landscape type.5. The "3S" technology provided the powerful support to the data analyses in this article. It has obtained some new experience: during the image interpretation the GPS data provided some informations to distinguish patches. Using the ERDAS IMAGINE8.4 software to made Post-Classification Process should change some steps...
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