November 2012

NASA/TM–2012-217788

Use of Windbreaks for Hurricane Protection of 

Critical Facilities

Simone Hyater-Adams

Hampton University, Hampton, Virginia

Russell J. DeYoung

Langley Research Center, Hampton, Virginia
NASA STI Program . . . in Profile

Since its founding, NASA has been dedicated to the 

advancement of aeronautics and space science. The 

NASA scientific and technical information (STI) 

program plays a key part in helping NASA maintain 

this important role. 

The NASA STI program operates under the 

auspices of the Agency Chief Information Officer. 

It collects, organizes, provides for archiving, and 

disseminates NASA’s STI. The NASA STI 

program provides access to the NASA Aeronautics 

and Space Database and its public interface, the 

NASA Technical Report Server, thus providing one 

of the largest collections of aeronautical and space 

science STI in the world. Results are published in 

both non-NASA channels and by NASA in the 

NASA STI Report Series, which includes the 

following report types: 

 TECHNICAL PUBLICATION. Reports of 

completed research or a major significant phase 

of research that present the results of NASA 

Programs and include extensive data or 

theoretical analysis. Includes compilations of 

significant scientific and technical data and 

information deemed to be of continuing 

reference value. NASA counterpart of peerreviewed formal professional papers, but 

having less stringent limitations on manuscript 

length and extent of graphic presentations. 

 TECHNICAL MEMORANDUM. Scientific 

and technical findings that are preliminary or of 

specialized interest, e.g., quick release reports, 

working papers, and bibliographies that contain 

minimal annotation. Does not contain extensive 

analysis. 

 CONTRACTOR REPORT. Scientific and 

technical findings by NASA-sponsored 

contractors and grantees. 

 CONFERENCE PUBLICATION. 

Collected papers from scientific and 

technical conferences, symposia, seminars, 

or other meetings sponsored or cosponsored by NASA. 

 SPECIAL PUBLICATION. Scientific, 

technical, or historical information from 

NASA programs, projects, and missions, 

often concerned with subjects having 

substantial public interest. 

 TECHNICAL TRANSLATION. 

English-language translations of foreign 

scientific and technical material pertinent to 

NASA’s mission. 

Specialized services also include organizing 

and publishing research results, distributing 

specialized research announcements and feeds, 

providing information desk and personal search 

support, and enabling data exchange services. 

For more information about the NASA STI 

program, see the following: 

 Access the NASA STI program home page 

at http://www.sti.nasa.gov

 E-mail your question to help@sti.nasa.gov

 Fax your question to the NASA STI 

Information Desk at 443-757-5803 

 Phone the NASA STI Information Desk at 

443-757-5802 

 Write to: 

 STI Information Desk 

 NASA Center for AeroSpace Information 

 7115 Standard Drive 

 Hanover, MD 21076-1320 
National Aeronautics and 

Space Administration

Langley Research Center 

Hampton, Virginia 23681-2199

November 2012

NASA/TM–2012-217788

Use of Windbreaks for Hurricane Protection of 

Critical Facilities

Simone Hyater-Adams

Hampton University, Hampton, Virginia

Russell J. DeYoung

Langley Research Center, Hampton, Virginia
Available from:

NASA Center for AeroSpace Information

7115 Standard Drive

Hanover, MD 21076-1320

443-757-5802

Acknowledgements

The authors express their gratitude to NASA HQ funding under the Climate Adaptation 

Science Investigator program that supported this research.
1

Abstract 

The infrastructure of the Langley Research Center is under 

potential risk in the future because of more intense hurricanes with 

higher speed winds and flooding. A potential method of protecting the 

Center’s facilities is the placement of a windbreak barrier composed of 

indigenous trees. The “New Town” program that is now in progress 

creates a more condensed area of focus for protection. A potential design 

for an efficient tree windbreak barrier for Langley Research Center is 

proposed. 

Introduction 

 NASA Langley Research Center is a facility that impacts countless people throughout the country 

and across the world. Since its federal opening in 1917, the center has contributed to the advancement of 

aeronautics and science by working towards NASA’s goals. On an economic scale, the center had a 2.1 

billion dollar impact nationally in the past year [1]. The research programs taking place at the facility deal 

with aeronautics, space exploration, and global climate. These projects are handled and managed by the 

1900 civil servants and 1800 contractors employed at the center proving that Langley is a value to the 

nation. 

 The center’s location on the coast of the Chesapeake Bay creates risks to the infrastructure due to 

storms that the area encounters, the most dangerous being hurricanes. Damage to the infrastructure due to 

these conditions would affect not only thousands of jobs, but the progress of many NASA projects. 

Langley is in a process of new construction called the “New Town” Program which will consolidate the 

majority of Langley’s buildings into a smaller infrastructure footprint while many outlying buildings will 

be demolished. This process of rebuilding which began in 2009 is focused on modernizing the center’s 

facilities. Figure 1 shows a map of the New Town area and the year when each renovation will be 

complete. The bulk of Langley’s campus will be located in this area by the time of the program’s 

completion in 2018, making it the focus for disaster protection. 
2

2. Hurricane Risk 

 Hurricanes are common in the Chesapeake Bay area, with five major storms hitting the area 

within the century. Figure 2 shows a map of the hurricanes whose paths have gone through the 

Chesapeake Bay Area between 1851 and 2009[2]. It is evident from the figure that the most frequent 

passes were of tropical storms and hurricanes of category 1 and 2, and rarely a category 3. These types of 

storms have winds ranging from 30mph to 130mph with storm surges ranging from 4 to 12 feet. Although 

the most frequent storms that have passed through were category 3 and below, there are studies that show 

there will be a shift in this pattern due to global climate change [3]. Models of future hurricane projection 

show a decrease in lower category (1-3) hurricanes and an increase of higher category (4 and 5) expected 

to hit land in the future. Figure 3 shows a graph of the projected hurricane changes in the Atlantic over the 

21st century. [4]. 

Figure 1. Layout of “New Town” 

Program Area. 
3

Figure 2. Map of storm and hurricane paths through the Chesapeake Bay area between 1851 and 

2009. 

Figure 3. Graph of the projected hurricane changes over the 21st century. 
4

These types of storms prove to be a great threat to Langley’s facilities. The high winds and 

flooding can cause drastic damage to the infrastructure of the center. Therefore, the need for 

a method of protecting the center is essential in the coming years, especially if the trends of 

Figure 3 are realized. 

3. Physics of Protective Windbreaks 

 Windbreaks can be defined as protective structures built to decrease wind flow to 

a specific area. There are different materials that are used to build these structures, but the 

most beneficial protection of Langley’s facilities would be a tree windbreak. Tree 

windbreaks are composed of tree rows of different heights, densities, and properties that are 

arranged and positioned in a specific way to decrease winds. Figure 4 shows the schematic 

of how wind breaks work. The air hits the windbreak and some is slowed down by the 

barrier and passes through, and some is pushed over the top of the windbreak, leaving an 

area behind the windbreak of much lower wind speed. 

Figure 4. Windbreak Schematic 

The keys to a successful tree windbreak are height and porosity. The length of protection that a 

wind break provides is a factor of the height of the tallest tree row ranging from 5 times the 

height on the windward side of the windbreak out to 30 times the height on the leeward side. The 

maximum wind reduction of a windbreak usually extends out to 10 times the height of the tallest 
5

tree row, but some reduction can extend out to 30 times the height. Figure 5 shows the 

relationship between windbreak tree height, x, the length of protection, and the amount of wind 

speed reduction [5]. 

Figure 5. Wind management schematic that shows the relationship between wind speed 

reduction and height of windbreak. [5] 

The density of the windbreak is important because of turbulence. If the structure is too dense, 

there is low porosity, forcing the wind over the trees and turbulently down the other side. The 

schematic in Figure 6 shows how the air flow changes with the density of the trees in a 

windbreak. When winds become turbulent they tend to create gusts of wind in different 

directions. When dealing with high speed winds, these gusts can become damaging to the 

infrastructure that the windbreak is meant to protect. 

Figure 6. Diagram showing the turbulence caused by windbreaks that are too dense. 

Wind breaks are most efficient when they have no openings, but if there are needs for breaks in 

the barrier for access points, they should be built in a specific way. In order to avoid wind tunnel 
6

effects within the windbreak, gaps should be angled so that the windbreak can still have an 

effect. Figure 7 below shows an example of appropriate angled gaps in a windbreak and an 

inappropriate straight cut gap. 

Figure 7. Diagram of the appropriate gaps for effective windbreaks. 

The use of tree windbreaks to protect fields and infrastructure is not a new idea. There are many 

successful windbreaks being used to protect homes, farms, and crops across the country. 

Windbreaks can be used not only for a barrier against wind, but also for privacy and a shield 

from snow. Pictured in Figure 8, is a half mile long windbreak in Iowa that has been successfully 

protecting a crop field for 15 years. This windbreak design is composed of five rows [6]. 

Figure 8. Iowa Windbreak composed 

of red cedar, white pine, Norway and 

White spruce, along with 7 kinds of 

oaks [7]. 
7

Another successful wind break is pictured in Figure 9 protecting a farmstead. The angled trees 

create an area of protection for the infrastructures from wind and snow. This windbreak has been 

successfully used for 10 years [7]. 

Figure 9. Ten year old windbreak composed of white pine and honeysuckle. [7] 

4. Preliminary Design of “New Town” Protective Windbreak 

In order to efficiently protect Langley’s “New Town” area from high winds, a windbreak design 

must have the following characteristics: Tall trees for maximum protection distance, sufficient 

porosity, fast growing trees that can sustain the Hampton Roads climate and adapt to Langley’s 

soil. The placement of the windbreak should be determined by the wind direction of potential 

hurricane winds. Data from NOAA on past wind speeds and directions in the Chesapeake Bay 

area show that most high winds from storms over the last 20 years were from the northeast [8]. 

Figure 10 shows a wind rose of this data for the New Town area. The wind rose diagram pictured 

in Figure 10 shows the wind speed, direction, and frequency. The numbers along the x-axis of 

the diagram are assigned to a circle and represent the scale of how frequent each wind speed 

occurred in each direction over the past years. 
8

Figure 10. The Langley New Town area with respect to the directions of past high winds. 

According to this wind data, the path for high winds is from the northeast. This means 

that the placement of the windbreak should be along the northeastern side of the facility. This 

works well with the “New Town” program because this is where the majority of the current 

infrastructure will be demolished for the renovation. A placement design for the wind break is 

shown on the map in Figure 11 along with the protection distances. 

Falling trees must be considered when determining the placement of the windbreak. 

Winds from storms shown in figures 2 and 3 do not pose the threat of creating tree projectiles 

that could cause damage to infrastructure during a storm. A NOAA website describes the types 

of damage done to infrastructure and tree projectiles are only a threat with winds over 90 mph 

[9]. Therefore, Langley’s windbreak must be placed far enough away from infrastructure that it 

cannot cause damage because of falling trees. 
9

Figure 11. Possible placement of Langley windbreak providing protection of New Town area. 

In order for this windbreak placement to be effective, the tallest tree row would be at least 

100 feet, creating an overall protective length up to 3,000 feet. The other rows of trees will 

be used only to create the right density. The proposed design consists of four rows minimum 

of a mixture of dense conifers and tall broad leaf trees. Figure 12 shows the set-up of the 

rows within this windbreak design. The first two rows at the windward side (to the left) 

contain the shorter trees in the design, small to medium conifer rows that are spaced closer 

together. The next two rows are on the leeward side and consist of taller trees, and medium 

to tall broadleaf trees that are spaced a bit farther apart. This design is composed of dense 

and broad trees to create a good amount of porosity and the right height to protect the area 

needed. Adding double rows of the middle trees to thicken the windbreak can add to the 

effectiveness of the design. 
10

Figure 12. Langley Windbreak Potential 4-row Design. 

The types of trees used for the windbreak must be carefully chosen in order to be effective. The 

trees must be indigenous or able to grow in the Virginia climate and medium to poorly drained 

soils because of the heavy flooding caused by hurricanes. They must be fast growing so that 

the windbreak can become effective as soon as possible. The trees must be durable enough to 

withstand the high winds that they will experience with the minimal amount of breaking. The 

trees proposed for this windbreak are as follows: Arborvitae, green ash, and black alder for the 

first two rows, and bald cypress, Norway spruce and American Sycamore for the last two rows. 

Table 1 below lists these selections along with the characteristics that make them qualify along 

with the cost ranges of the trees. Overall, the cost estimate of the trees in the windbreak can 

range from 13 to 19 thousand dollars according to arborday.org, fastgrowingtrees.com, 

windbreaktrees.com and tnnursery.net. 
11

Table 1. Recommended trees for the Langley windbreak that are indigenous to Virginia and have 

the required characteristics. 

5. Conclusion 

Langley Research Center is a value to not only the science community but the nation as a whole. 

The intense hurricanes projected for the future of Hampton Roads pose a threat to the center’s 

infrastructure and research projects. The “New Town” Program plans to create an area of 

renovated and new buildings that are more condensed, creating an area of focus for protection in 

the center. The windbreak proposed is focused on protecting this new area, and should be able to 

be effective not long after the time of its completion. In addition to being a barrier for protecting 

Langley from wind, the tree windbreak can produce a few other benefits. It can help soak up 

water from flooding, beatify the campus and provide nature for walking trails, and create habitats 

for the wildlife on the center. The use of a well-designed tree windbreak barrier is a cost 

effective, environmentally friendly way to protect the center from inclement weather high winds 

of the future. 
12

References 

1. “2011 A Year of Visible Change.” National Aeronautics and Space Administration. NP2011-12-354-LaRC. 

2. NOAA. National Hurricane Center. <http://www.nhc.noaa.gov/>. 

3. Bender, Morris A. “Modeled Impact of Anthropogenic Warming on the Frequency of 

Intense Atlantic Hurricanes.” Science, vol 327, p. 454. 22 January 2010. 

4. Knutson, T.R. Tropical Cyclones and Climate Change”. Nature Geoscience, vol 3, p.157. 

March 2010. 

5. "Why Plant A Windbreak?" Ohio Department of Natural Resources. Web. 30 July 2012. 

<http://ohiodnr.com/portals/18/landowner/pdf/windbreaks_guide.pdf>. 

6. Tamang, Bijay, and Michael G. Andreu. "Windbreak Designs and Planting for Florida 

Agricultural." University of Florida IFAS Extenion, Web. 

7. "WindbreakTrees.com." WindbreakTrees.com. Web. 25 June 2012. 

<http://www.windbreaktrees.com/index.html>. 

8. NOAA. National Climatic Data Center. < http://www.ncdc.noaa.gov/oa/ncdc.html>. 

9. "Saffir-Simpson Hurricane Wind Scale." Saffir-Simpson Hurricane Wind Scale. NOAA 

National Hurricane Center, Web. 30 July 2012. 

<http://www.nhc.noaa.gov/aboutsshws.php>. 

10. Brandle, James R., Xinhua Zhou, and Laurie Hodges. "How Windbreaks Work." 

University of Nebraska Lincoln Extension. Web. 

<http://www.nfs.unl.edu/documents/howwindbreakswork.pdf>. 

11. Capatex Ltd. "Windbreaks for Horticulture: A Guide For The Professional." Web. 

<http://www.capatex.com/agro_web/techinfo/windbreakguide/fullguide_4web.pdf>. 

12. Hanley, Donald P., and Gary Kuhn. "Trees Against The Wind." Pacific Northwest 

Extension,Web. 

13. Jones, Chapin. "Common Forest Trees of Virginia." Common Forest Trees of Virginia. 

Web. 20 June 2012. <http://www.newrivernotes.com/va/vatrees.htm>. 
13

14. "NASA Langley Research Center: Continuing a Legacy of Aerospace Success." NASA. 

Ed. Bob Allen. Web. 30 July 2012. 

<http://www.nasa.gov/centers/langley/news/factsheets/fs-2010-01-178.html>. 

15. "Selecting Trees and Shrubs for Windbreaks." University of Minnesota Extension, Web. 

<http://www.extension.umn.edu/agroforestry/components/selecting-trees-and-shrubs-inwindbreaks.pdf>. 

16. Slusher, John P., and Doug Wallace. "Planning Tree Windbreaks in Missouri." University 

of Missouri Extension. Web. <http://extension.missouri.edu/p/G5900>. 

17. <http://edis.ifas.ufl.edu/fr289>. 

18. Wilson, Jon S., and Scott J. Josiah. "Windbreak Design." NebGuide. University of 

Nebraska-Lincoln Extension, Web. 

<http://www.nfs.unl.edu/documents/windbreakdesign.pdf>. 

19. "Windbreak 101 Pdf Free Ebook Download from Www.cccdwy.net." EbookBrowse.com. 

Web. 21 June 2012. <http://ebookbrowse.com/windbreak-101-pdf-d277649474>. 
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

2. REPORT TYPE 

Technical Memorandum

 4. TITLE AND SUBTITLE

Use of Windbreaks for Hurricane Protection of Critical Facilities

5a. CONTRACT NUMBER

 6. AUTHOR(S)

Hyater-Adams, Simone; DeYoung, Russell J.

 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center

Hampton, VA 23681-2199

 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

 8. PERFORMING ORGANIZATION

 REPORT NUMBER

L-20191

10. SPONSOR/MONITOR'S ACRONYM(S)

NASA

13. SUPPLEMENTARY NOTES

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified - Unlimited

Subject Category 31

Availability: NASA CASI (443) 757-5802

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email: help@sti.nasa.gov)

14. ABSTRACT

The protection of NASA Langley Research Center from future hurricanes is important in order to allow the center to fulfill its 

mission. The impact of the center is not only great within NASA but the economy as well. The infrastructure of the Center is 

under potential risk in the future because of more intense hurricanes with higher speed winds and flooding. A potential method 

of protecting the Center’s facilities is the placement of a windbreak barrier composed of indigenous trees. The “New Town” 

program that is now in progress creates a more condensed area of focus for protection. A potential design for an efficient tree

windbreak barrier for Langley Research center is proposed.

15. SUBJECT TERMS

Hurricane barrier; Protection; Trees

18. NUMBER

 OF 

 PAGES

18

19b. TELEPHONE NUMBER (Include area code)

(443) 757-5802

a. REPORT

U

c. THIS PAGE

U

b. ABSTRACT

U

17. LIMITATION OF 

 ABSTRACT

UU

Prescribed by ANSI Std. Z39.18

Standard Form 298 (Rev. 8-98)

3. DATES COVERED (From - To)

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

509496.02.08.03.69

11. SPONSOR/MONITOR'S REPORT

 NUMBER(S)

NASA/TM-2012-217788

16. SECURITY CLASSIFICATION OF:

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, 

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this 

collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and 

Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person 

shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

01- 11 - 2012