Imaging and locating paleo-channels using geophysical data from meandering system of the Mun River, Khorat Plateau, Northeastern Thailand
| Autor: | P. Nimnate, Montri Choowong, T. Thitimakorn, K. Hisada |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
floodplain
geography QE1-996.5 geography.geographical_feature_category Plateau Floodplain gpr 0208 environmental biotechnology Geology 02 engineering and technology Environmental Science (miscellaneous) 010502 geochemistry & geophysics 01 natural sciences 020801 environmental engineering paleo-channel meandered scar Ground-penetrating radar General Earth and Planetary Sciences ert Geomorphology 0105 earth and related environmental sciences |
| Zdroj: | Open Geosciences, Vol 9, Iss 1, Pp 675-688 (2017) |
| ISSN: | 2391-5447 |
| Popis: | The Khorat Plateau from northeast Thailand, the upstream part of the Mun River flows through clastic sedimentary rocks. A massive amount of sand was transported. We aimed to understand the evolution of fluvial system and to discuss the advantages of two shallow geophysical methods for describing subsurface morphology of modern and paleo-channels. We applied Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR) to characterize the lateral, vertical morphological and sedimentary structures of paleo-channels, floodplain and recent point bars. Both methods were interpreted together with on-sites boreholes to describe the physical properties of subsurface sediments. As a result, we concluded that four radar reflection patterns including reflection free, shingled, inclined and hummocky reflections were appropriated to apply as criteria to characterize lateral accretion, the meandering rivers with channel-filled sequence and floodplain were detected from ERT profiles. The changes in resistivity correspond well with differences in particle size and show relationship with ERT lithological classes. Clay, silt, sand, loam and bedrock were classified by the resistivity data. Geometry of paleo-channel embayment and lithological differences can be detected by ERT, whereas GPR provides detail subsurface facies for describing point bar sand deposit better than ERT. |
| Databáze: | OpenAIRE |
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