At a given location, under normal conditions a river flows with a Manning coefficient of 0.030, and a cross section as indicated in Fig. P10.61a. During flood conditions at this location, the river has a Manning coefficient of 0.040 (because of trees and brush in the floodplain) and a cross section as shown in Fig. P10.61b. Determine the ratio of the flowrate during flood conditions to that during normal conditions.
