地球信息科学学报 ›› 2016, Vol. 18 ›› Issue (2): 220-226.doi: 10.3724/SP.J.1047.2016. 00220

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基于区域生长的黄土地貌沟沿线提取方法与实验

刘玮(), 李发源*(), 熊礼阳, 刘双琳, 王轲   

  1. 1. 南京师范大学 虚拟地理环境教育部重点实验室,南京 210023
    2. 江苏省地理信息资源开发与利用协同创新中心,南京 210023
  • 收稿日期:2013-11-15 修回日期:2014-03-26 出版日期:2016-02-10 发布日期:2016-02-04
  • 通讯作者: 李发源 E-mail:1810204017@qq.com;li_fayuan@sina.com
  • 作者简介:

    作者简介:刘 玮(1991-),女,山东潍坊人,硕士生,研究方向为数字地形分析和图像处理。E-mail: 1810204017@qq.com

  • 基金资助:
    基金项目:国家自然科学基金项目“基于DEM的黄土地貌沟沿线研究”(41171299)、“基于DEM的黄土沟壑种群特征及空间异质性研究”(41271438)、“基于DEM的黄土高原地表蚕食度及空间分异研究”(41201464)

Shoulder Line Extraction in the Loess Plateau Based on Region Growing Algorithm

LIU Wei(), LI Fayuan*(), XIONG Liyang, LIU Shuanglin, WANG Ke   

  1. 1. Key Laboratory of Virtual Geographic Environment of Ministry of Education, Nanjing Normal University, Nanjing 210023, China
    2. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China
  • Received:2013-11-15 Revised:2014-03-26 Online:2016-02-10 Published:2016-02-04
  • Contact: LI Fayuan E-mail:1810204017@qq.com;li_fayuan@sina.com

摘要:

沟沿线是黄土地貌正负地形的分界线,地形在沟沿线处存在较大的高程变化和坡度转折。坡面畸变邻域法是一种有效提取沟沿线的方法,但该方法对正负地形进行分割时,往往会产生大量的碎屑多边形和分类错误,严重影响沟沿线的提取精度。为了解决这个问题,本文采用区域生长方法来改进坡面畸变邻域法的提取结果。首先,分别以DEM提取的山顶点和出水口点作为正负地形的生长点进行4邻域生长,生长至正负地形边界或大于坡度阈值为止;然后,采用边缘检测方法提取正负地形分界线;最后,依据形态学图像处理方法去除“毛刺”得到最终的沟沿线。结果显示,该方法实现了对沟沿线的自动提取,解决了由于正负地形分类错误造成的沟沿线定位不准确的问题,提高了沟沿线的提取精度,同时该方法也较好地保持了沟沿线的完整性和连续性,对黄土高原不同地貌类型具有普遍的适用性。

关键词: 沟沿线, 区域生长, 图像形态学, 坡面畸变邻域法, DEM

Abstract:

Shoulder line is one of the most effective terrain structure line used to describe the loess landform. It plays an important role in the study of the spatial distribution and landform evolution of the loess landform. Shoulder line lies on the boundary of the positive and negative terrain, where the elevation and slope of the loess surface reveal obvious changes. Many efforts have been done for the extraction of shoulder line, but these methods have disadvantages, of which the experimental process requires human intervention or the shoulder line is discontinuous. P-N terrain method can effectively extract the shoulder line, but while using this method to segment the positive and negative terrains, it tends to produce large amounts of broken polygons and classification errors, which affect the accuracy of shoulder line. This paper investigates a region growing algorithm to improve the P-N terrain method. Using the highest elevation of the local area as a growing point for positive terrain and the outlet as a growing point for negative terrain, four-neighborhood growth were carried out until they reached the boundary of the positive and negative terrains or a slope threshold. Then the edge detection method was used to extract the critical boundary. Finally, the morphological image processing method was used to eliminate burrs to get the final shoulder line. In order to verify the result, this paper used the 0.6 m resolution remote sensing image to get the relatively accurate shoulder line by visual interpretation. And then different results were compared using overlay analysis. It is revealed that the shoulder line extracted using the improved method is closer to the visual interpretation results. This method is an automatic way to extract shoulder line, which solves the inaccurate location problem of P-N terrain method. Meanwhile, this method keeps the integrity and continuity of shoulder line and avoids the emergence of broken shoulder line and closure shoulder line. The use of morphological image processing method in burrs removal also ensures the accuracy.

Key words: shoulder line, region growing, morphological image processing, P-N terrain method, DEM