Example application of the geomorphic analog method.

A plan view of a design reach and a reference reach. The design reach has an estimated anastomosing channel and no suitable locations for a reference cross section. Equations are provided to calculate the appropriate bankfull area, bankfull width, and bankfull depth of the design reach cross section based on the reference reach cross section. The difference between a cross section at a single thread reference reach and a cross section at an anastomosing channel is shown. Calculate Q bankfull based on the slope and mannings n or D84 of the Pebble count at the reference reach cross section. The mean bankfull depth is the bankfull area divided by the bankfull width. The design bankfull area is equal to the reference reach bankfull area multiplied by the discharge of the bankfull design reach divided by the discharge of the bankfull reference reach. The design bankfull width is the square root of the bankfull width at the reference reach divided by the mean bankfull depth of the reference reach times the bankfull area of the design reach. The mean bankfull depth of the design reach is equal to the bankfull area of the design reach divided by the bankfull width of the design reach. The max bankfull depth of the design reach is equal to the mean bankfull depth the design reach divided by the mean bankfull depth of the reference reach times the max bankfull depth of the reference reach