Formation and development of stream potholes in a gorge in Guangdong

• Published in: Journal of geographical sciences Vol. 19; no. 1; pp. 118 - 128
• Main Authors: Wang, Wei, Liang, Mingzhu, Huang, Shan
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science in China Press 01-02-2009; Springer Nature B.V
• Subjects: Asia; Bgi / Prodig; China; Earth and Environmental Science; Fieldwork; Flow pattern; Freshwater; Geographical Information Systems/Cartography; Geography; Miocene; Nature Conservation; Physical Geography; Potholes; Remote Sensing/Photogrammetry; Statistical methods; Streambeds; 壶穴形态; 广东大峡谷; Guangdong; China; Guangdong China; China, People's Rep; Guangdong gorge; morphological feature; stream pothole; Channel geometry; Geomorphogenesis; Turbulence; Stream; Fluvial erosion
• ISSN: 1009-637X; 1861-9568
• DOI: 10.1007/s11442-009-0118-9

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 method- ologies. 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.