基于RS与GIS的森林景观空间异质性研究——以杭州市余杭区为例

Analysis on the Spatial Heterogeneity of Forest Based on RS and GIS——A Case Study on the Forest Landscape in Yuhang District in Hangzhou City

利用Landsat ETM遥感影像、森林分布图和实地调查数据,借助于RS和GIS工具,选取了景观组分比例、边界密度、斑块密度、斑块平均大小、景观多样性指数、景观均匀度指数和景观优势度等指标对浙江省杭州市余杭区西部山区的森林景观进行分析,来研究该区森林景观的空间异质性。研究结果表明:该区域森林景观的6种主要组分中,竹林无论斑块数量还是面积大小都占优势,而灌木林则较少;研究区整体破碎化程度较高,表现为边界密度和斑块密度都比较大,由于受人类活动的影响大,经济林要高于其它类型,但整个景观或不同区域不同景观类型的破碎化程度差别不大;研究区整体及各乡镇多样性、均匀度、优势度均不高,表明该区域景观组分比较单一,人类应减少不合理干扰,对森林进行科学的调控以消除或减少森林景观的潜在威胁。

In the support of the RS and GIS technology, with the help of Landsat ETM image, forest distribution map and the investigation data, six indices such as landscape patterns ratio, mean patch area, edge density, patch density, landscape diversity index, Shannon＇s evenness index and dominance were put forward to analyze the patterns of forest landscapes in Yuhang district, Hangzhou city, Zhejiang Province. The results showed that the forest landscape of the area consisted of 6 components, among which the forest of bamboo was the most important landscape type with the biggest area and most patches in the study area, while those of the shrub were the least; the fragmentation of the whole landscape was high, because of the high edge density and high patch density, for the larger effect on the forest of human, the edge density and patch density of economic forest were higher than those the others; the landscape diversity index, Shannon＇s evenness index and dominance of the whole district and the different towns were not high, which indicts that the vegetation patters were simple. In order to rehabilitate the forest landscape ecology and maintain the landscape security patterns, the reasonable regulations and managements of human activities should be strengthened, while the unreasonable should be reduced.