Problem $5.$

Consider a drainage basin of $1,000$ hectares having $60\%$ soil group B and $40\%$ soil group C$.$

Five years ago, the watershed land use pattern was $1/2$ wooded area with good cover and $1/2$

pasture with good condition.

Now the land use has been changed to $1/3$ wooden area, $1/3$ pasture land, and $1/3$ residential area

$(1/4-$ acre lot$).$

Estimate the increased total runoff volume by the NRCS method due to the land use change over

the past five$-$year period for a $180$ mm storm under the wet antecedent moisture condition. $($Note: $1$

hectare $=10,000$ m$2$

; $1$ inch $=25\mathrm{.}4$ mm$).$