River behavior at a highway crossing depends not only on the stability of that particular river reach, but also on the behavior of the entire fluvial system of which it is a part. Rivers are complex landforms. A simple and straight forward approach to the identification of river hazards is not always possible. A complete evaluation of hydraulic hazards cannot be solely based on on-site hydrologic, hydraulic and geomorphic factors; but must also include insight into historic trends, synoptic consideration of basin characteristics, and anticipation of future changes. Because determination of stream-related hazards is a complex task it is beneficial to generalize relative stability based on stream type. Streams can be divided into five types based on channel pattern and mode of sediment transport. Each stream type exhibits its own characteristic stability. Detailed evaluation involves consideration of many variables. After evaluating stream variables a list of potential stream hazards can be developed. Each potential hazard can be evaluated on an individual basis and properly considered in either the design of a new crossing or maintenance of an existing one. Numerous evaluation methods are available to hydraulic engineers that have not been fully utilized. To assess hydraulic hazards at a crossing it is necessary to understand the past, examine the present, and anticipate the future. Methods such as remote sensing, land use evaluation and slope stability analysis should not be overlooked. (FHWA)

Media Info

  • Media Type: Digital/other
  • Pagination: 252 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00335586
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-RD-80-160 Final Rpt., FCP 35H1-062
  • Files: NTL, TRIS, USDOT
  • Created Date: Nov 23 1981 12:00AM