ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Quaternary Science, Geomorphology and Paleoenvironment

Volume 13 - 2025 | doi: 10.3389/feart.2025.1594817

Geomorphologic Feature and Its Tectonic Significance in the Middle and Upper Reaches of Yunnan Section of the Lancang River Basin

Provisionally accepted
Sheng  LISheng LI1Yuanhua  QingYuanhua Qing2*Na  LiNa Li3Nannan  LuNannan Lu4Shuang  YangShuang Yang2Yufan  XuYufan Xu1,5Jingnan  LiuJingnan Liu1Ruotong  LiuRuotong Liu2Hao  HeHao He2
  • 1云南省地震局, 昆明市, China
  • 2School of History, Geography and Tourism, Chengdu Normal University, Chengdu, Sichuan Province, China
  • 3Chengdu University of Technology, Chengdu 610059,, Chengdu, China
  • 4四川省地震局, Chengdu 610041, China, China
  • 5Yunnan Earthquake Agency, Kunming 650224, China, Kunming, China

The final, formatted version of the article will be published soon.

This paper extracted the fifth-level river system and 158 sub-basins in the middle and upper reaches of the Yunnan section of the Lancang River based on the ASTER GDEM data with a resolution of 30 m and ArcGIS software. By calculating relief, slope, hypsometric integral (HI), basin shape index (BS), stream length-gradient index (SL), and geomorphic information entropy of each sub-basin, and comprehensively considering rainfall, rock strata, and tectonics, this paper discusses the geomorphic features and tectonic significance of the middle and upper reaches of the Yunnan section of the Lancang River Basin. The research shows that: The middle and upper reaches of Yunnan section of the Lancang River Basin is in its middle age. The sub-basin shapes are mainly circular and square. The secondary river systems in the upper reaches are in the vertical drainage stage, while the secondary river systems in the middle reaches are still in the longitudinal drainage stage. The distributions of relief, slope, HI, SL, and BS are mainly controlled by tectonic activities, and the influences of rock strata and rainfall on the geomorphology are limited. In the areas of Jianchuan-Eryuan-Yangbi-Dali and the southern section of the middle reaches of the Lancang River, the tectonic uplift has stagnated and evolved into the erosion-deposition stage. The southern part of Deqin County and the southern part of Weixi County are in the uplift stage, while the tectonic uplift in the areas of Yunlong-Yongping-Luning has entered the attenuation stage. In the study area, the activity intensities of the Lanping-Yongping fault and the Weixi-Qiaohou fault are higher in the northern section and lower in the southern section. The Lancangjiang fault has a low activity intensity at the "S"-shaped big bend, while the tectonic activity in the northern section is strong. However, the tectonic activity in the southern section of the Longpan-Qiaohou fault and the northeastern section of the Nantinghe fault are weak.

Keywords: Hypsometric integral, Basin shape index, Stream length-gradient index, Water system style, Lancang River basin, Lancangjiang fault

Received: 17 Mar 2025; Accepted: 20 May 2025.

Copyright: © 2025 LI, Qing, Li, Lu, Yang, Xu, Liu, Liu and He. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Yuanhua Qing, School of History, Geography and Tourism, Chengdu Normal University, Chengdu, 611130, Sichuan Province, China

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