天绘一号卫星影像的平原绿化提取方法

Study on Plain Afforestation Area Extraction with Mapping Satellite-1 Imagery

平原绿化是我国平原地区森林植被的主体,为生态环境建设提供了有力保障。但平原绿化分布零散,斑块面积小,不易被准确提取。本文以河南省封丘县为例,利用天绘一号卫星影像面向对象分类技术提取了平原绿化。在面向对象分类过程中,针对不同平原绿化信息选取不同的分割尺度和参数,建立影像对象的分割层次结构,确保农田林网、通道防护林、四旁防护林等平原绿化信息能够被准确分割。分类时通过构建隶属度函数,利用层与层之间的关系,子类继承父类的分类特征,在此基础上增加自己的特征,建立分类规则集,逐层提取绿化信息。本文共获取封丘县平原绿化面积152.51 km2,其中,农田林网36.09 km2,通道防护林21.29 km2,四旁防护林71.56 km2,片林23.57 km2。利用验证点数据,对分类结果进行精度评价,总体分类精度为93.50%,Kappa系数达到0.92。

Plain afforestation refers to the non-crop vegetation in crop-dominated plain area. As the main forest vegetation it has provided favorable conditions for ecological environment construction. The plain afforestation in this paper mainly includes farmland shelterbelt, road shelterbelt, residence shelterbelt and wasteland shelter- belt. But due to their small patches, getting the information of plain afforestation requires high spatial resolution remote sensing imagery. And the different sizes of kinds of afforestation patches make it difficult to extract all of them at once. In addition, it is a problem, if they could be extracted all, to distinguish themselves from one anoth- er. Based on this point, the paper explores a more accurate object-oriented classification method based on Map- ping Satellite-1 （MS 1） imagery in Fengqiu County, Henan province, China. The innovation of this method lies in the selection of proper segmentation scale according to different kinds of plain afforestation. Build optimal seg- mentation levels to insure the farmland shelterbelt, road shelterbelt, residence shelterbelt and wasteland shelter- belt could be segmented from their background imagery completely. Then contrast and analyze the spectral and spatial characteristics of different afforestation to develop classification rule sets. The classification rule sets could be conveyed between levels and current class could inherit them from parent class. Then build membership function to extract the plain afforestation area hierarchically. The results showed that the plain afforestation area of Fengqiu is 152.51 km^2. More specifically, the farmland shelterbelt area is 36.09 km^2, the road shelterbelt area is 21.29 km^2, the residence shelterbelt area is 71.56 km^2, and the wasteland shelterbelt area is 23.57 km^2. The classification accuracy is 93.50% and the Kappa coefficient is 0.92. It showed that the study have achieved fine classification results. And the results also verified the potential of object-oriented plain afforestation information extraction based on Mapping Satellite-1 （MS 1） imagery. This method can provide a technical support for the area accurate estimation of plain afforestadion.