Curve number method $(15$ points$)$: A $200-$acre watershed is $40\%$ rural and $60\%$ urban land. The rural area is $40\%$ cultivated land with conservation tillage, $35\%$ pasture in good condition, and $25\%$ forest land with good cover. The urban area is residential: $60\%$ is $\frac{1}{2}$ acre lots in good condition, $25\%$ is $1/4$ acre lots in poor condition, and $15\%$ is roads. Compute the runoff depth from the watershed for $5$ in of rainfall, assuming AMC II conditions. The entire watershed is in hydrological soil group B$.$

Estimate the runoff depth in $2$ different ways and answer the following questions:

a$.$ Ist compute a weighted curve number, then estimate a depth for the entire watershed.

b$.2$nd calculate runoff for each land use separately $[$cultivated land, pasture, forest, urban $(\frac{1}{2}ac,$ and urban $(\frac{1}{4}ac],$ then calculate the area$-$weighted average to get a watershed$-$level depth.

c$.$ Are the results from the $2$ methods the same or different?

d$.$ Which land use had the most runoff per unit area $($e$.$g$.$ depth$)?$

e$.$ Which land use had contributed the most runoff overall $($e$.$g$,$ volume$)?$