地理科学进展 ›› 2014, Vol. 33 ›› Issue (1): 42-49.doi: 10.11820/dlkxjz.2014.01.005

• 2013年全国地貌与第四纪学术研讨会专栏 • 上一篇    下一篇

基于DEM的黄土塬形态特征分析及发育阶段划分

仝迟鸣1,2, 周成虎1, 程维明1, 张文杰1,2, 王娇1,2, 刘海江3   

  1. 1. 中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室, 北京100101;
    2. 中国科学院大学, 北京100049;
    3. 中国环境监测总站, 北京100012
  • 收稿日期:2013-10-01 修回日期:2013-12-01 出版日期:2014-01-25 发布日期:2014-01-22
  • 通讯作者: 程维明(1973-),男,甘肃天水人,副研究员,主要从事数字地貌与地学信息图谱研究,E-mail:chengwm@lreis.ac.cn。 E-mail:chengwm@lreis.ac.cn
  • 作者简介:仝迟鸣(1989- ),女,山西怀仁人,硕士生,主要研究方向为数字地形地貌分析,E-mail:tongcm.11s@igsnrr.ac.cn。
  • 基金资助:
    国家自然科学基金项目(41171332);国家科技支撑计划项目(2012BAH28B01-03);科技基础性工作专项项目(2011FY110400-2);中国科学院地理科学与资源研究所“一三五”战略科技计划项目(2012ZD009)。

Morphological characteristics and developmental stages of loess tablelands based on DEM

TONG Chiming1,2, ZHOU Chenghu1, CHENG Weiming1, ZHANG Wenjie1,2, WANG Jiao1,2, LIU Haijiang3   

  1. 1. State Key Laboratory of Resource and Environmental Information System, Institute of Geographic Science and Natural Resources Research, CAS, Beijing 100101, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. China National Environmental Monitoring Centre, Beijing 100012, China
  • Received:2013-10-01 Revised:2013-12-01 Online:2014-01-25 Published:2014-01-22

摘要: 基于DEM的地形分析方法已被广泛应用于地貌学研究中,但当前研究以定性或半定量居多,利用各类参数对大面积区域的量化分析研究较少。本文以黄土高原为研究区,利用GIS 及DEM地形分析方法,将坡度小于15°的正地貌提取出来,然后利用坡度与起伏度结合分析得到黄土塬顶面,两者相减得到黄土塬坡面,最终提取黄土塬1106 个;选取黄土塬核心区的106 个样本,分别计算坡面平均坡度、顶面长短轴比、沟壑密度、顶面与底面比、地面裂度5 个指标,然后对其分别进行等级划分,计算5 个指标的几何平均值,作为评价研究区黄土塬相对年龄的指标;对组合指标(I)进行分析后,将其划分为3 级,分别为早期(I<1.74)、中期(1.74≤I<2.12)和晚期(I≥2.12)。研究结果显示,在黄土塬的不同发育阶段,各个形态指标整体上存在差异,各子类型内部也存在发育先后不一致的情况。在对黄土塬各子类型计算发育阶段指数之后发现,从黄土塬、黄土残塬到黄土梁塬,I值逐渐增大。形态指标的有序变化与前人研究所得的黄土地貌发育过程十分一致。

关键词: DEM, 黄土高原, 黄土塬, 相对年龄, 形态参数

Abstract: DEM-based terrain analysis has been widely used in geomorphology. Currently most researches are qualitative or semi-quantitative, whereas quantitative analyses of large areas based on a variety of parameters are few and far between, and most studies use artificial field measurement with a small scale in the aspect of the relative age of the landscape entity. So, in this article, by using 30 m ASTER-GDEM, GIS and digital terrain analysis method, we extracted morphological parameters of a wide range of the areas of loess tablelands and determined their relative ages. We tried to provide basic knowledge of multi scale representation of the loess tablelands and fine landforms, achieved quantitative descriptions of the similarities and differences among the loess tablelands, and calibrated their developmental stages. First, we extracted positive landforms less than 15° in the Loess Plateau. Then, we acquired the top surface of the loess tableland using two parameters: gradient and waviness. We determined 1106 loess tablelands based on the subtraction between positive landform layer and the top surface layer. We selected 106 loess tablelands as samples to calculate average slope, axial ratio of top surface, gully density, top and bottom area ratio, percentage of negative terrain. The geometric mean of these five parameters was used as an index to estimate the relative age of the loess tableland. The index (abbreviated to I) was categorized into three levels: early development (I<1.74), middle development (1.74≤I<2.12) and late development (I≥2.12). The results showed that: (1) the morphological parameters of loess tablelands are different from one another in different developmental stages; (2) developmental stages are also inconsistent for the subtypes; (3) transitional type exhibits the characteristics more similar to the type of the previous stage. After calculating I of each subtype, we found that from early to late stages of the loess tablelands, I value increases gradually, which is consistent with other researchers' conclusions on the developmental stages of loess landforms.

Key words: DEM, Loess Plateau, loess tableland, morphological parameter, relative age

中图分类号: 

  • P931.6