Journal of Geographical Sciences ›› 2009, Vol. 19 ›› Issue (1): 58-66.doi: 10.1007/s11442-009-0058-4

• Climate and Environmental Change • Previous Articles     Next Articles

Geometric properties of river cross sections and associated hydrodynamic implications in Wuhan–Jiujiang river reach, the Yangtze River

ZHANG Qiang1, SHI Yafeng1, XIONG Ming2   

  1. 1. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology,CAS, Nanjing 210008, China|
    2. Changjiang Water Resources Commission (CWRC), Ministry of Water Resources, Wuhan 430010, China
  • Received:2007-10-25 Revised:2008-05-15 Online:2009-02-25 Published:2009-02-25
  • Supported by:

    National Natural Science Foundation of China, No.40701015; Key Project of National Natural Science Foundation of China, No.40730635

Abstract:

Based on measured hydrological data by using ship-mounted Acoustic Doppler Current Profiler (ADCP) instrument, we analyzed shapes of river cross sections of the middle Yangtze River basin (mainly focusing on Makou and Tianjiazhen river reach). Hydrodynamic properties of river channels were also discussed. The research results indicate that nonlinear relationships can be identified between river-width/river-depth ratio (W/D ratio), sizes of cross section and mean flow velocity. Positive relations are detected between W/D ratio and mean flow velocity when W/D<1; and negative relations are observed when W/D>1. Adverse relationships can be obtained between W/D ratio and cross-section area. Geomorphologic and geologic survey indicates different components of river banks in the wider and narrower river reaches respectively. These may be the main driving factors causing unique hydrological properties of river channels in the middle Yangtze River basin. Narrower river cross sections tend to raise water level in the upstream river reach near narrower river channel, giving rise to backwater effects. River knots can cause serious backwater effects, which is harmful for flood mitigation. However river knots will also stabilize river channel and this will be beneficial for river channel management. The results of this paper may be helpful for flood mitigation and river channel management in the middle Yangtze River basin.

Key words: Wuhan–Jiujiang river reach, river cross section, hydrodynamic property, Acoustic Doppler Current Profiler (ADCP)