Journal of Geographical Sciences ›› 2009, Vol. 19 ›› Issue (1): 118-128.doi: 10.1007/s11442-009-0118-9

• Climate and Environmental Change • Previous Articles    

Formation and development of stream potholes in a gorge in Guangdong

WANG Wei1, LIANG Mingzhu2, HUANG Shan1   

  1. 1. Geography and Quaternary Environment Institute, South China Normal University, Guangzhou 510631, China|
    2. Tourism Institute, Jinan University, Guangzhou 510632, China
  • Received:2008-03-29 Revised:2008-06-10 Online:2009-02-25 Published:2009-02-25
  • Supported by:

    National Natural Science Foundation of China, No.40871020; Guangdong Natural Science Foundation, No.7005836

Abstract:

The goal of this study is to provide information on the process of pothole growth on a gorge streambed. Pothole geometries were measured in a reach of the Dabu river bed at the head of a gorge more than 200 m deeply incising into a 650–750 m high planation surface formed in the middle Miocene in northern Guangdong, China. Geometric and derivative data of the potholes obtained from fieldwork were interpreted using standard statistical methodologies. Our study shows that the formation and development of a stream pothole were only related to local conditions of a stream reach where the pothole occurs; the weaknesses, which are usually intersect fractures, typically interconnected vertical joints, or triangular pits generated by hitting of rock fragments during floods, initiate the pothole development on a streambed; the geometrical dimensions of the potholes are controlled by tectonic joints developed in bedrock of the stream reach; the radius and the depth of potholes are strongly (log) positive correlated; the pothole shapes and the flow patterns are inconstant during pothole growth; a pothole can be formed within a short period, but cannot be fully developed and maintained for a long time in a strong incision streambed. The finding in our study can improve the understanding of Quaternary environment in Guangdong.

Key words: Guangdong gorge, stream pothole, morphological feature