Improving geological mapping by using high-resolution DEM: An example from the fold-thrust belt around the Taipei region
| Autor: | Chia-Hung Chiu, 邱家宏 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 In recent years, with the advancement of high resolution DEM and computing powers, we have been able to construct and display high-resolution DEM in a three-dimensional environment. Through human identification, program calculation and ArcGIS software, this study set up a three-dimensional space to analyze and identify surface topography in sedimentary rock areas. Based on the geological background accumulated by the predecessors, the high-resolution DEM-derived geological maps were completed and checked. The study area is in northern Taiwan near the eastern part of the Taipei Basin and consists of sedimentary rocks from the Oligocene to the Pliocene times. The stratigraphic units and tectonic structures within the fold-thrust belt generally exhibit a northeast-southwest trend. In the study, three-dimensional geological maps were drawn through ArcGIS with high-resolution DEM. The slope map and hillshade map derived from high-resolution DEM and the DEM itself are used as the main three-dimensional terrain identification base maps. The interlayers of sandstone and shale or structures resulted from differential erosion were used for sedimentary rock layers identification to establish the structural features of the study area. The study has successfully produced a 1:50000 geological map of the Taipei Sedimentary Rock Area and three 1:25,000 small-area geological maps. Two geological profiles are drawn to show the distribution of structures in the area. For the first time, a large-area two-dimensional geological map was created by using three-dimensional numerical topography in the sedimentary rock area. A procedure of producing three-dimensional DEM geological map was proposed in this study. Through existing geological frameworks and data, this study provides mapping methods for the refinement and renovation of existing geological maps of sedimentary rock areas. This study demonstrates that high-resolution DEM can be used for mapping areas of sedimentary rocks, particularly for areas with dense vegetation, sparse exposure and inaccessibility. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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