资源科学 ›› 2017, Vol. 39 ›› Issue (10): 1989-1999.doi: 10.18402/resci.2017.10.17

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中国西南喀斯特地区正负地形的提取方法研究

李婧昕1,2(), 许尔琪2()   

  1. 1. 北京林业大学自然保护区学院,北京100083
    2.中国科学院地理科学与资源研究所陆地表层格局与模拟重点实验室,北京100101
  • 收稿日期:2017-08-23 修回日期:2017-09-05 出版日期:2017-10-20 发布日期:2017-10-20
  • 作者简介:

    作者简介:李婧昕,女,吉林通化人,硕士,主要研究方向为基于GIS的自然保护区规划与管理。E-mail:li_jx@bjfu.edu.cn

  • 基金资助:
    国家自然科学基金项目(41601095);国家重点基础研究发展计划(973计划)(2015CB452702)

Extraction of positive and negative terrain boundary in Karst region of Southwest China

Jingxin LI1,2(), Erqi XU2()   

  1. 1. School of Nature Conversation,Beijing Forestry University,Beijing 100083,China
    2. Key Laboratory of Land Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China
  • Received:2017-08-23 Revised:2017-09-05 Online:2017-10-20 Published:2017-10-20

摘要:

中国西南喀斯特地区在地貌形态上主要表现为以峰丛为主的正地形和以洼地为主的负地形。近年来,以正地形为主的喀斯特地区石漠化程度日益加剧,对这一地区生态修复的前提是进行合理的正负地形划分。本文以西南喀斯特7个典型地貌类型区为例,基于地表开度、地表曲率和地形起伏度三个地形因子,应用改进的局部方差法和阈值法确定最终的正负地形边界。结果显示,研究区正负地形分界处地表开度最佳阈值介于-2°~-4°之间,正地形比例从42.80%~75.57%不等。最后,选取了三个景观格局因子对正负地形的差异加以描述,并分析了耕地在正负地形中的形态差异。今后不同地形因子组合对地表描述准确程度的定量化研究及形态学方法与边缘检测等计算机自动提取方法的融合将是重点探讨的方向。

关键词: 正负地形, 中国西南喀斯特地区, 地表开度, 地表曲率, 地形起伏度, 阈值分割, 坡耕地

Abstract:

Southwest China has the largest continuous distribution of Karst in the world,which is mainly characterized by a positive terrain of peak-cluster and negative terrain depression. Affected by human production activities,the degree of Karst rocky desertification in positive terrain is now serious. Ecological restoration in these areas must be given high priority,so the division of positive and negative terrain is especially important. In this paper,seven typical terrain areas and three terrain factors including openness,curvature and relief amplitude based on a digital elevation model were selected. Then,average local variance was improved and used to calculate the openness difference binary image through threshold segmentation to obtain a boundary of positive and negative terrain with the reference of other two factors. The results showed that the optimal threshold was between -2 to -4 degrees and the positive terrain proportion was 42.80%~75.57%. To describe the morphological differences in positive and negative terrain,three landscape pattern indices were chosen. Taking the slope gradient distribution of slope land in positive terrain areas as an example,morphological difference was described between positive and negative terrain. In future,two aspects may attract attentions: one is the fusion of different terrain factors on quantifying accuracy of surface description and the other is combination of geomorphic morphological methods and computer automatic extraction,such as edge detection.

Key words: positive and negative terrain, Karst of Southwest China, openness, curvature, relief amplitude, threshold segmentation, slope land