Evaluate the stability of the rectangular channel wit the following known information.

$[17]$

Flow rate:

$Q=30\frac{m^3}{s}.$

Specific weight of sediment: $=2\mathrm{.}85.$

Channel slope:

Base width

$S=0\mathrm{.}5\%$

Chezy constant:

Delta

$B=12m.$

$C=64.$

$\frac{RS}{D}=0\mathrm{.}0924$

$=1\mathrm{.}65$

Chezy:

$V=C\sqrt[\phantom{2}]{RS}$

$C=18log(\frac{12R}{K})$

Determine the particle size to prevent scouring.