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公路建设对区域的各种生态过程、灾害活动等影响引起广大学者的关注,目前对小尺度区域公路沿线景观格局的影响效应研究较少。利用3S技术对云南省昆明市东川区蒋家沟小流域内县乡级公路沿线三期影像的景观进行分类和制图,运用Fragstats3.3软件和景观指数计算方法,从斑块和景观两个层次上研究公路建设前后景观格局的变化。结果表明:(1)不同时期建设公路及全部公路沿线均出现坡耕地显著减少、梯田显著增加的趋势;在不同距离梯度上,针叶林、灌丛、坡耕地景观百分比不断降低,梯田、草地面积增加。(2)公路沿线景观格局动态变化则表现为:在斑块层次上,1973年前建设公路沿线景观形态更复杂,破碎化程度高,1973年后建设公路沿线阔叶林、针叶林斑块数量增加,破碎化趋势明显;在景观层次上,公路沿线景观多样性增加,景观内部连通性降低,整体景观格局破碎化加剧,但1973年前建设公路沿线空间连接性有所提升,1973年后建设公路沿线则表现出空间连接性下降的趋势,公路全线两侧150 m范围对景观水平指数的影响最大。
The impact of highway construction on various ecological processes and disasters in the region has aroused the attention of the majority of scholars. At present, there are few researches on the effect of the landscape pattern along the scale of small-scale areas. Using 3S technology to classify and map the three-phase landscape images of the county-level roads in the Jiangjiagou watershed, Dongchuan District, Kunming, Yunnan Province. Using the Fragstats3.3 software and landscape index calculation method, Study the changes of landscape pattern before and after highway construction at different levels. The results showed that: (1) There was a significant decrease in sloping farmland and terraced fields along the road construction and in all roads at different periods; the landscape percentage of coniferous forest, shrub and sloping farmland continued to decrease at different distance gradients, Area increases. (2) The dynamic changes of the landscape pattern along the highway show as follows: At the level of the plains, the landscape pattern along the highway before 1973 is more complicated and the degree of fragmentation is higher. After 1973, the broad-leaved forest, coniferous forest patches The number increased and the trend of fragmentation was obvious. On the landscape level, the diversity of landscape along the highway increased, the connectivity within the landscape decreased, and the overall landscape pattern became more fragmented. However, the spatial connectivity along the road before construction increased in 1973. After 1973 The road connectivity along the highway shows a tendency of decreasing connectivity. The impact of the 150 m range on both sides of the highway on the landscape level index is the greatest.