5.6 Managing Shade

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Shade cast by buffers can be a key design factor. For example, where roads are maintained to be free of snow and ice, buffers should be set back from the road to allow sunlight on the road surface. Where roads are maintained with snowpack, constant shade may be desirable to avoid ice. Buffers and their effect on drifting snow should also be considered (see 5.7).

Use the formula s = h/tan A to calculate shadow length. See the table below for an example. Sun angle calculators are available on the Web which will provide the sun angle (A) and azimuth angle for a given location based on the date and time.

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The azimuth angle is used to plot the shadow direction on the ground. Plotting the shadows throughout the day for key times during a year will be useful for designing the buffer (e.g., 2.12, 4.4, and 4.7).

DOWNLOAD: 5.6 Guidelines and References (PDF)