Assessment of channel stability from field study and the comparison of time-sequential aerial photographs provides information that is needed in site selection, bridge design, and countermeasure placement. Channel instability is indicated by bank erosion, progressive degradation (or aggradation) of the streambed, or natural scour and fill of the streambed. Bank erosion rates are related to stream type and are proportional to stream size. Predictions of future rates are based on past rates, as measured on time-sequential photographs or maps, and on the typical behavior of meander loops. Significant degradation of the streambed can usually be detected from indirect field evidence. The sites of greatest potential scour along a channel can be identified from channel configuration. Shift of the thalweg, which is a factor in the alignment of piers, is related to stream type and can be assessed from aerial photographs. (Author)

Media Info

  • Media Type: Print
  • Features: Figures; Maps; Photos; References;
  • Pagination: pp 163-171
  • Monograph Title: Second bridge engineering conference. volumes 1 and 2
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00390826
  • Record Type: Publication
  • ISBN: 03090036593
  • Files: TRIS, TRB
  • Created Date: Dec 30 1984 12:00AM