Agriculture Reference
In-Depth Information
establishing or determining the elevations (spot elevation) of two points,
one at the uphill point and one on the downhill point of the sloping fea-
ture. To create a 5 percent slope, as shown in Figure 12.2, the designer
would need to establish the elevations for spot elevations A and B. The
elevation is given for spot elevation A: 34.5´. In order to calculate the ele-
vation of point B, the designer would
need to first know and be working
with a scaled plan, and then would
have to decide the percent of slope of
the walkway wanted between points A
and B. Once the slope is determined—
in this case it is 5 percent—the
designer would measure the horizon-
tal distance between the two points,
then apply the formula S = V / H to cal-
culate the elevation of point B. Assume
the horizontal distance between the
two points as measured with a scale
on the plan is 35 feet.
35
34
33
32
Figure 12.2
Sloping walkway leading from a parking lot to an
upper building area
S = V / H
.05 = V / 35
V = -05 × 35
= 1.85 feet
Finally, to calculate the elevation
of point B, subtract the answer from
the given calculation (1.85) from the
elevation of point A. If point A was
35.5´ then the elevation for point B is:
A
B
35.5 - 1.85 = 33.65'
The same procedure for deter-
mining the elevation of a spot ele-
vation of the ground could also be
used in locating the new position of a
contour, assuming a desired percent
Figure 12.3
Locating the contours that help create a 5 percent
slope on this walkway. Knowing elevations and the beginning of
a slope (A) and the bottom of a slope (B) one can determine loca-
tion of intermediate contours between the two points.
