Composite Cross$-$section:

Given conditions:

$S=1$:$1000=0\mathrm{.}001$

$n1=n3=$ vegetation

n$2=$ unfinished concrete

able $12-1$ Surface Roughness Coefficient

$\begin{array}{cc}\text{P}\text{e}\text{r}\text{i}\text{m}\text{e}\text{t}\text{e}\text{r}& n\\ \text{E}\text{a}\text{r}\text{t}\text{h}\text{c}\text{h}\text{a}\text{n}\text{n}\text{e}\text{l}& 0\mathrm{.}02-0\mathrm{.}04\\ \text{G}\text{r}\text{a}\text{s}\text{s}\text{l}\text{a}\text{n}\text{d}& 0\mathrm{.}05-0\mathrm{.}1\\ \text{S}\text{p}\text{a}\text{r}\text{s}\text{e}\text{v}\text{e}\text{g}\text{e}\text{t}\text{a}\text{t}\text{i}\text{o}\text{n}& 0\mathrm{.}07-0\mathrm{.}15\\ \text{H}\text{e}\text{a}\text{v}\text{y}\text{w}\text{e}\text{e}\text{d}\text{s}& 0\mathrm{.}017-0\mathrm{.}025\\ \text{F}\text{i}\text{r}\text{m}\text{s}\text{o}\text{i}\text{l}& 0\mathrm{.}02-0\mathrm{.}035\\ \text{S}\text{m}\text{o}\text{o}\text{t}\text{h}\text{s}\text{o}\text{i}\text{l}& 0\mathrm{.}035-0\mathrm{.}050\\ \text{G}\text{r}\text{a}\text{v}\text{e}\text{l}\text{s}\text{u}\text{r}\text{f}\text{a}\text{c}\text{e}& ?\\ \text{R}\text{o}\text{c}\text{k}\text{y}\text{s}\text{u}\text{r}\text{f}\text{a}\text{c}\text{e}& 0\mathrm{.}012-0\mathrm{.}018\\ \text{A}\text{r}\text{t}\text{i}\text{f}\text{i}\text{c}\text{i}\text{a}\text{l}\text{l}\text{y}\text{l}\text{i}\text{n}\text{e}\text{d}\text{c}\text{h}\text{a}\text{n}\text{n}\text{e}\text{l}& 0\mathrm{.}012-0\mathrm{.}019\\ \text{S}\text{t}\text{e}\text{e}\text{l}& 0\mathrm{.}022-0\mathrm{.}030\\ \text{C}\text{a}\text{s}\text{t}\text{i}\text{r}\text{o}\text{n}& 0\mathrm{.}010-0\mathrm{.}013\\ \text{C}\text{o}\text{r}\text{r}\text{u}\text{g}\text{a}\text{t}\text{e}\text{d}\text{m}\text{e}\text{t}\text{a}\text{l}& 0\mathrm{.}012-0\mathrm{.}016\\ \text{F}\text{i}\text{n}\text{i}\text{s}\text{h}\text{e}\text{d}\text{c}\text{o}\text{n}\text{c}\text{r}\text{e}\text{t}\text{e}& 0\mathrm{.}011-0\mathrm{.}015\\ \text{U}\text{n}\text{f}\text{i}\text{n}\text{i}\text{s}\text{h}\text{e}\text{d}\text{c}\text{o}\text{n}\text{c}\text{r}\text{e}\text{t}\text{e}& 0\mathrm{.}013-0\mathrm{.}018\\ \text{P}\text{r}\text{e}\text{c}\text{a}\text{s}\text{t}\text{c}\text{o}\text{n}\text{c}\text{r}\text{e}\text{t}\text{e}& 0\mathrm{.}010-0\mathrm{.}013\\ \text{B}\text{r}\text{i}\text{c}\text{k}\text{s}\text{u}\text{r}\text{f}\text{a}\text{c}\text{e}& ?\end{array}$

A $-$ Compute the velocity $V$ and volume flowrate $Q$ for the central "main" channel flowing at bank$-$full condition, $y=1\mathrm{.}5m.$

$B-$ Compute velocity $V$ and volume flowrate $Q$ for the floodplain sections, $y=1\mathrm{.}0m$

C $-$ Compute $Q$ for the flow condition shown:

main channel $y=2\mathrm{.}5m,$ floodplain channel $y=1\mathrm{.}0m.$

D $-$ Compute average velocity for flow condition shown, $V=\frac{Q}{A}$

$E-$ Compute $R_e$ and $F_r$ for floodplain section

$1$Composite Cross$-$section:

Given conditions:

S $=1$:$1000=0\mathrm{.}001$

n$1=$ n$3=$ vegetation

n$2=$ unfinished concrete

A $$ Compute the velocity V and volume flowrate Q for the central

$$main$$ channel flowing at bank$-$full condition, y $=1\mathrm{.}5$ m$.$

B $$ Compute velocity V and volume flowrate Q for the floodplain

sections, y $=1\mathrm{.}0$ m

C $$ Compute Q for the flow condition shown:

main channel y $=2\mathrm{.}5$ m$,$ floodplain channel y $=1\mathrm{.}0$ m$.$

D $$ Compute average velocity for flow condition shown, V $=$ Q$/$A

E $$ Compute Re and Fr

for floodplain section