The total area of a site is 26,134 sf. The surface types, runoff coefficients, a

PrincessWas

试卷: LEED AP ID+C 模拟试卷C[查看]
The total area of a site is 26,134 sf. The surface types, runoff coefficients, and areas of the site are as follows:
Surface Runoff Coefficient Area (sf)
Asphalt Pavement 0.95 9,678;
Pervious Pavement 0.65 6,454;
Gravel 0.75 3,632;
Turf, Flat (0-1% slope) 0.25 6,370;

What amount of impervious area does the site have?
A: 32%
B: 72%
C: 68%
D: 95%

参考答案: C

本题解释:
Reference: Sustainable Sites Credit, Site Selection, Stormwater Design-Quantity Control, Calculation

Imperviousness = total pervious area (sf) / total site area (sf)

Multiply each surface by the runoff coefficient to calculate the total impervious area.
Surface Runoff Coefficient Area (sf) Impervious Area (sf)

----------------------------------------------------------------------------

Asphalt Pavement 0.95 9,678 9,194

Pervious Pavement 0.65 6,454 4,195

Gravel 0.75 3,632 2,724

Turf, Flat (0-1% slope) 0.25 6,370 1,593

Total area: 26,134 sf
Total impervious area: 17,706 sf (add up all 4 columns of surfaces)
Imperviousness: 17,706 sf / 26,134 sf = 68%