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关键词：防护林;植被指数;GF-2;遥感;信息提取
中图分类号：S127 ; S757; F301.21文献标识码：A 文章编号：1006-8023（2018）06-0013-07
Research on Rapid Extraction of Shelter Forest Using GF-2 Images Based on Vegetation Indices
LIU Ting， BAO Guangdao*， ZHANG Dawei， HE Huaijiang， LUO Ye， ZHANG Zhonghui
（Jilin Provincial Academy of Forestry Sciences， Changchun 130033）
Abstract： In this study， 0.8 m GF-2 satellite image was taken as the main data source. According to the vegetation index characteristics of shelter forest， the method of GF-2 remote sensing image to quickly extract shelter forest through vegetation index was studied. The extraction thresholds of the ratio vegetation index （RVI）， the difference vegetation index （DVI） and the normalized difference vegetation index （NDVI） were determined by sample point feature analysis and comparative analysis， respectively. The Landsat8 OLI image was used as a mask to remove the interference information of the forest land in the construction land， and the image was binarized to obtain the extraction results of the three vegetation indexes of the shelter forest. The results show that the overall accuracy of forest belt identification using RVI， DVI and NDVI are 89.2%， 90.4% and 88.3%， respectively， both are above 85%， indicating that these three methods can extract the information of shelter forest very accurately. Among them， DVI method has relatively accurate extraction result， and it can provide more detailed information when the forest belt is interlaced and the forest belt spacing is small， which is helpful for the accurate identification of forest belt information. This study can provide scientific support for the monitoring of current status and remote sensing inversion of large-scale shelterbelts in Northeast China.
Keywords： Shelter forest; vegetation index; GF-2; remote sensing; information extraction
0 引言
防護林是指以防护效应作为基本经营目的，由人工林和天然林组成的森林总称[1]。防护林可为生态较为脆弱地区的经济环境、土地资源、农业生产、畜牧养殖，建筑设施和居住环境提供保护，防止或减轻所保护地区的自然灾害，或避免不利因素的损害和干扰[2-3]，对提高作物产量和增强气候变化下的稳定性具有潜在优势，降低非农投入水平[4]，为社会提供多种的外部效益[5]。常规的防护林调查和识别方法一般以高成本、费时、费力的野外实地调查和遥感影像人工解译为主。由于遥感技术具有宏观、综合、动态和快速等特点，可快速提供大范围空间数据，而逐渐被广泛应用于林业动态监测和制图中，目前已成为防护林调查的主要技术手段。随着遥感技术的快速发展，时间、空间和光谱分辨率的不断提高，传统方法逐渐无法满足实际工作对调查效率的需求，简单、快速、精准的防护林识别方法，能够减少人力物力投入，增加调查效率、提高调查精度。