A Methodology for Predicting Channel Migration NCHRP Project No. 24-16

Abstract

Stream channel migration can have a significant impact on the design, maintenance, and inspection of bridges and other highway facilities. Practicing highway hydraulic engineers could benefit from a practical methodology to predict the rate and extent of channel migration in their efforts to reduce the cost of design, repair, rehabilitation, and countermeasures for lateral channel instability. The objective of Research Project 24-16 is to develop a practical methodology to predict the rate and extent of channel migration (i.e., lateral channel shift and down valley migration) near transportation facilities. The research approach for this project emphasizes enhancing and using empirical databases to develop predictive multiple regression or other statistical relationships, which include descriptors of, or surrogates for, bankline erodibility and floodplain characteristics. This will be accomplished through a series of tasks including: 1) a detailed literature review; 2) compilation and analysis of an extensive data set containing time-sequential aerial photography, stream gage data, and field measurement data from a variety of sources; 3) development of a screening procedure to identify stable meandering reaches; 4) development of a classification system for river/meander types to support stratification of the database; 5) development of guidelines for map/aerial photograph comparison techniques for predicting meander migration; 6) development of multiple regression relationships for predicting direction, location, and rate of meander migration; and 7) internal and external testing and evaluation of the methodology.