Acta Geographica Sinica ›› 2016, Vol. 71 ›› Issue (3): 412-421.doi: 10.11821/dlxb201603005

• Geomorphology • Previous Articles     Next Articles

The neotectonic activity of Wanchuan catchment reflected by geomorphic indices

Yan DAI1(), Xianyan WANG1(), Shengli WANG2, Yiquan LI1, Huayu LU1   

  1. 1. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
    2. School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
  • Received:2015-11-12 Revised:2015-12-27 Online:2016-03-25 Published:2016-03-30
  • Supported by:
    National Natural Science Foundation of China, No.41522101

Abstract:

Wanchuan River, located in the northeastern Tibetan Plateau, is one of the tributaries of the Yellow River. This area has witnessed many earthquakes of magnitude 6 on the Richter scale. Based on DEM data, this paper discussed the characteristics of neotectonic activity by analyzing the drainage networks and calculating geomorphic indices. It turns out that the mountain front sinuosity index is between 1.03 and 1.18 to the north of Wanchuan River (NWR) and from 1.83 to 2.88 in Xinglong Mountain (XLM); while the valley floor height-to-width ratio index is about 0.36-2.34 in NWR while it ranges from 0.55 to 13 in XLM. The values and distribution of the mountain front sinuosity index and the valley floor height-to-width ration indicate that neotectonics are still active in the study area, and the movements in the north of Wanchuan River catchment are more active. The abnormal AF index in the southeast part means that there should be tilted fault block and folds in the northwest of Wanchuan River catchment. There exists a strike-slip fault in the southeast of the northern Wanchuan River valley, indicated by analyses of the distribution of knickpoints and off-set valley.

Key words: geomorphic indices, river longitudinal profiles, regional tectonic, fault, Wanchuan River