| Vegetation as an important ecological factor is the bearer of climate change, showed positive feedback effect for climate change, and a reflection of the sensitive ecological indicator of environmental changes. The research and monitoring in regional vegetation was great significance for vegetation protection especially the rational use of vegetation resources.Based on SPOT VGT 1km resolution data S10, we analyzed the spatiotemporal variations of NDVI in Zhejiang Province in 2001-2009. Then the dimidiate pixel model was used to determine vegetation coverage of Qingyuan County from 1994 to 2007 based on multi-temporal Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) image data. Finally, with the help of the second class survey of forest resource, landscape regeneration design was done to the Chinese fir forests along Qingyuan No.54 Provincial Highway, which had a tendency of recession found by the remote sensing monitoring. This study builds up the technology system of monitoring vegetation coverage with different scales and landscape regeneration design for forest, which can provide certain reference for ecological environment construction.In the study period, the vegetation cover in the Province had a slowly increasing trend, the area with a significant increase of NDVI occupied 29.40% of the total, which mainly distributed in mountain district, and the area with a significant decrease of NDVI occupied 5.06% of the total, which mainly distributed in Hangjiahu Plain and Ningshao Plain. Compared to the past8 years, in 2009, the area with a significant increase of NDVI occupied 11.39% of the total, which mainly distributed in central south mountain district, Linshui City and Wuyin County were Typical Examples. The area with a significant decrease of NDVI occupied 14.36% of the total, which mainly distributed in plain district. This shows the fact that the social and economic development, urban construction has a very negative impact on the vegetation coverage.From 2001 to 2009, all the types of forest had a significant increasing of NDVI, except natural mixed forest, artificial mixed forest and artificial broad leaved forest. The vegetation cover in artificial coniferous forests, artificial bamboo and natural bamboo had a better increasing trend. The forest vegetation cover conversion in Shengzhou City and Lanxi City etc took vegetation restoration as important, while Tongxiang City etc took vegetation degradation as important.Results showed that in 2007, 90.8% of the total area was considered a high vegetation coverage area with 657.4 km2 of the medium high vegetation coverage area during these 13 years being converted into high vegetation coverage, especially from 1994 to 1999. During the research period, the steeper sloping area had higher vegetation coverage. However, the less the slope, the faster the vegetation coverage increased with gently sloping areas (<15○) increasing to over 15% coverage. Results of vegetation coverage change showed that in the eastern part of Qingyuan County, vegetation restoration was favorable from 1994 to 1999 as it was in the Baishanzu Nature Reserve from 1999 to 2007. Also, during the 13 year research period, the landscape fragmentation index continuously decreased, whereas the mean patch size increased, especially for the high vegetation coverage area that saw an increase from 9.66 to 182.82 ha. Thus, from 1994 to 2007, vegetation coverage in Qingyuan County increased favorably. Our study confirms that this is a feasible approach in the estimation of vegetation coverage over large area from remote sensing data.Focusing on the degradation of forest stands, taking the landscape design of Chinese fir forests of Huangtian section in Qingyuan No.54 Provincial Highway as an example, a composite value evaluation system is set up for landscape sensitivity of forest along the highway, which can be used as foundation for the forest landscape regeneration design. Moreover,based on application of virtual reality technique in comparing the differences between scheme designs, this thesis proposed the practical strategy, systematic method for the landscape regeneration design of forest. |
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