TITLE:
Morphotectonic Analysis along the Eastern Chiang Khong Basin, Chiang Rai, Northern Thailand
AUTHORS:
Pichawut Manopkawee
KEYWORDS:
Mae Ing Fault Zone, Morphotectonic Analysis, Geomorphic Indices, Drainage Patterns, Mountain Front Sinuosity, Stream-Length Gradient Index
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.11 No.4,
April
30,
2023
ABSTRACT: Chiang Khong Basin (CKB) is a northeast-southwest active basin in Chiang Rai province, northern Thailand. The basin is bounded to the east by numerous fault segments of the Mae Ing Fault Zone (MIFZ), where they have triggered several previous earthquakes in Chiang Rai and vicinities. Although the slip of the MIFZ has triggered some earthquakes, the active deformation of the landscape affected by the tectonic processes of the MIFZ is mainly unknown. According to uniform lithologic and climatic conditions across the MIFZ, we rely on developing high-resolution digital elevation models and satellite images to identify lineaments and fault lines and evaluate tectonic activity along the eastern CKB. We conducted morphotectonic analysis on primary geomorphic indices of channel-hillslope coupling (drainage patterns, mountain front sinuosity (Smf), and stream-length gradient index (SL)) to define zones of active tectonics. These values efficiently imply the degree of tectonic activity. Our analysis reveals that most drainage patterns are dendritic, trellis, and rectangular, which indicate the patterns of joints and minor faults. The Smf values vary between 1 and 2.4, and the SL values reach the peak near the toe of the mountain and the fault segment’s line. The combination of the primary geomorphic indices suggests that the eastern CKB experiences a high level of active tectonics impacted by the active MIFZ. The study highlights morphometric analysis and geomorphic indices to estimate tectonic activity and evaluate the active deformation of the landscape in the region.