Water flows through two identical channels, each with a square cross$-$section of $3$m $3$m

carrying a flow rate of Q$1$ in each channel. These two channels are then combined into a

single channel with a width of $6$ m $$ wide while maintaining the same slope. The new

flow rate, Q$2$ is adjusted such that the water depth remains constant at $3$m$.$

Determine the ratio Q$2/$Q$1$