Synopsis:
Windbreaks are a major component of successful agricultural landscapes. At the farm scale, they help control erosion and blowing snow, improve animal health and survival under winter conditions, reduce energy consumption of the farmstead, and enhance habitat diversity. At a landscape scale, they provide habitat for various types of wildlife and have the potential to contribute significant benefits to the carbon balance equation, thereby easing the economic burdens associated with climate change. The effectiveness of a windbreak is determined partially by its external structure including its height, length, orientation, continuity, width, and cross-sectional shape and partially by its internal structure including the amount and distribution of solid and open portions, vegetative surface area, and shape of individual plant elements.
Windbreak height is the most important external structural element that determines the extent of wind protection. Measurements of air pressure upwind and downwind of a windbreak show that the pressure increases as the wind approaches the windbreak, drops as wind passes through the barrier then gradually returns to the original condition at or beyond 10 times the height of the windbreak.
Optical density is a measure of internal structure that is defined as the amount of solid material appearing in a two-dimensional photograph. The data for wind speed reduction by windbreaks for various optical densities presented in the paper suggests that windbreaks with higher optical densities produce higher wind speed reductions.
Conclusions:
The effectiveness of shelterbelts is determined partially by its external structure including its height, length, orientation, continuity, width, and cross-sectional shape and partially by its internal structure including the amount and distribution of solid and open portions, vegetative surface area, and shape of individual plant element
Thresholds/Learnings:
