基于DEM数据的菲律宾海典型区地貌类型划分

Landform classification for the Philippine Sea based on DEM data

  • 摘要: 深远海海底地质环境复杂,地貌形态多变,目前没有形成统一的地貌类型划分量化标准。本文主要针对这一问题,选择菲律宾海中南部典型区作为研究区,结合已有规范、标准和区域构造演化特征,提出了海山、海丘、海底裂谷、山间谷地、山间洼地、山间盆地6种四级地貌单元的量化划分标准。利用ArcGIS平台对DEM数据进行深度处理,提取高程、坡度、坡度变化率、地形起伏度等关键地貌因子,对研究区海山等地貌单元进行了定量化划分,明确了其分布特征。结果显示:受控于形成时期不同的构造背景,研究区西部与东部具有显著的构造走向差异,西部海岭呈近EW向雁式排列,东部海丘呈近NS向雁式排列,东部海丘相较于西部海岭更为狭长;海山、海丘和山间盆地等大规模地貌单元的形成往往受控于强烈的构造、岩浆活动。本次研究成果能够丰富深远海海底地貌类型划分和成因研究领域,为今后相关标准规范的制定奠定基础。

     

    Abstract: Submarine geomorphology plays significant roles in marine environmental and engineering studies, and the deep sea is specially complex in geomorphology. Based on the existing norms, standards and regional tectonic evolution characteristics, this paper takes the Philippine sea as the research object for study of deep sea geoenvironment. Quantitative standards are proposed and six different geomorphic units are identified, which include seamounts, hills, submarine rifts, mountain valleys, intermontane depressions, and intermontane basins. Based on DEM, ArcGIS is used to extract critical geomorphological factors such as elevation, slope, slope change and relief of land surface. Following the classification, the study area is quantitatively divided into six geomorphic units. Controlled by the tectonic stresses in different periods, the west part and the east part of the survey area show significant difference in tectonic strikes. The oceanic ridges in the west are arranged in a near-EW pattern, and the hills in the east are in a near-NS direction. Ridges are narrower in the west. Large-scale geomorphic units, such as seamounts and intermontane basins are often controlled by strong geological processes, such as magmatic, hydrothermal and tectonic activities. Facts have proved that this research is helpful to submarine landform classification and the study of their genesis. It can also contribute more to the formulation of relevant standards and specifications for deep sea geomorphological studies.

     

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