Table Of ContentRLO-2227-79/3
4 HANDBOOK ON THE USE OF TREES AS AN
INDICATOR OF WIND POWER POTENTIAL
E. W. Hewson, ef al
Oregon State University
Corvallis, Oregon
June 1679
ee
U.S, Department of Commerce
National Techwica! Infoimation Service
VE:
og} SVE OTAY
RtL0.2207-79°3
ium ary UE
[A manonocK on uz OEE OF
TREES AS ju WIDICATOR OP
WIND POWER eonErra.
PIMA SPORT
Boi, Hawnon
3.2, tnde
Ri Bakex
Departoont of Acnespheric sciences
‘Oregon Stare University
Corvallis, Oregon,
om
sane 1979
PREPRIED FOR THE UNITED SqaTCS
REPARTHENE OF ENERGY
RIVESIGH OF DISTRIBUTED SOLAR TECHNOLOGY
FEDERAL MIND FUERGY PROGEAX
DOE CONTRRGT Nn, EY 76~506-2227
‘TASK AGRERIT 24
ESTIONAL TECHNICAL
REQERATION seRviCe
<u
Set $0 72F
#
pormowroguenns
We would 1ike to acknoyledge 2 number of individuals whe
have contributed co the development of this technique or to the
wevles of this Danabsck Theke include: Or, William Pennell,
Pan Partch, S. 1. ULanski and Tony Olson of Pacific Northwest,
Yaboratory; De. Hareld Feites, wee Ring Laheratery, Uniwrriey
of Arizona; Dr. Harold Money, Departnent of Biological Sciences,
Stanford University: wicholos Butler of Bonneville Rewer Adminis
tration) Dy, Bisnara Holbe, Department Of Forestry, Oregon State
University (O80); De. Oonata Zobel, Dapartaient of Batamy, O8ts
and weuce Petersen, br. allan Murphy, James tuckley and Raymond
Witney of 08u"s Department of Atwspheric ScLences
We wuld also Like co thank mes. Patricia Bakhoye, our
secretary, for hor patience and careful typing of this report,
OFSCLAV.ER
ve book wo pend ata acount of Hak ONDE by aM tne of te Ui
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“Thin report has been epredaced eset from the best avluble copy.
_Avaabe (4am the Natgnat Techie lnfo-waon Serve, U.S. Deparment of
Conmetce Sprowhei, vagina 22h
a
ACCESSION 77198545
‘AUTHOR. Wadle, hn Edward, 1946.
{TTLE" Trees as an ineator of wind peer potential PLACE:
[Cervais, Or]
BUSLISHER: Dept oF Atmosphele Sciences, Oregon State Univers,
YEAR!“977
PUB TYPE: Bock
FORMAT: 10
‘SERIES AT microfiche reference itary: 27-491
NOTES: Merotena, Stanford, Calf: Appropriate Technology
Progeer, 18681 microfiche | 11s 15:em. (AT mcrolone reference
rary 21-491),
‘SUBJECT: Winds ~ Spood — Measursmert
OTHER: Hewson, €. Wendell Eagar Wendel), 1910-
‘Oregon State University Dest. of Abmosphevic Scierces.
ry
‘ACCESSION. 9958511
‘AUTHOR: Hewsan,E. Wane
"TILE: A handbook on the
potoetial
PLACE: Springfield, va
PUBLISHER: NTIS,
YEAR 1979
PUB TYPE, Book
FORMAT: 21 pi: 28cm
NOTES. Bibing-aphy » 21
DOE cansact no.
REPORT NO: RLO-2227-70,
SUBJECT: Wind power
GTHER Wade. John Edward, 1948
Baker, Robert W
Federal Wine Energy Program (US)
[Edgar Wendel), 1910
‘of wees as an nclicator of wind power
Cape off ate atthe Clevelond Publi Library ard Texas A&M
Univeraty Copies of #2 are atthe South Florida Water Ranayerent
Chet Library and the South Carina Ste Library.
RASOUTIVE sinOMRY
dn important first step in the effective utilization of wind
energy 49 the identification of locations with strong, persistent
winds. This handbook deseribes techniques for electing areas of
dood wind power potential using wind~detorned cenifer trees. wind~
Aoforned trees ware first used as yardsticks of wind power potential
by P.c. Putnas in his survey prior to installation of the Saith-
Putoam wind turbine at Grandpa's Inch. However, trees have been axed
for handreds of years az an evological indicator of wind dfrection,
wind exposure and az ¢ moacure of the beverity of wilt and Loc damage.
‘thin handbook will describe techniques for “reading” the infor-
mation weitien on tha trees by wind. Techniques are described fur
determining the vind direction from trees and how this information
can be used to Infer possible vind-flow pats
2. Seasonal varia
‘tions in the wind have a pronounced effect on the type of wind defor~
ation and these effects eve characterteed in ehia handbook.
‘Techniques for estimating the nean annual wind speed have been
developed uring thewe indices of wind effects on trees. thase indices
have been calibrated on two widely distributed species of conifers-~
pouglas-f8x and Ponderosa Pine, Tht handbook describes the methots
eed to verify the calibration, the applications of the tecunlquea
developed and their Linitations, one of the major Linttations pointed
out 45 that the indices are calibrated on only two species of conifer
trees found in the vestom United states. The next edition of this
handbook will extend these techniques to other types of trses found
An other areas of the country. Another inportant consideration is
chat, while wind-Elagyed trees generally indicate strong winds, the
absence of flagged trees should not be interpreted as indication oF
weak Winds but rather ag indleation that the winds aay be tas vari-
able in direction or that the divmal variation in the wind 46 50
‘great that vind flagging does not occur.
‘sreen alco provide an indication of the cocurrence of severe
wind and ice Josds, ay examining external danaze and intemal
tit
ovidence of damage in the tree rings, the occurrence of savera wind
‘of 10s Loads can be not only identified bot also cen be dated as to
‘the year thia damage occurred.
‘The main conclusions are that tres
provide a elmple, Lnexpen~
sive and quick ethod for identifying promising locations where sore
Getadled peasurenenta can verify tha wind power potential. ror the
eal vind eysten user, flagged trees might ba sufficlently quantita
tive evidence to justify installation of a wind enexgy ccaversion
ayetem, However, tha lack of flagged treen should not Alequalify a
potential eite but rather indicate the need for on-aite wind measure=
wenta prior ta wind systew Installation.
‘ame oF cons
weCniVE SBRY © Le
Lisp oP IDES.
MAST OF TRBES 2
PRODUCTION Se
FREES AS THDTCATORS OP PREVAILING WIND OTRECPIONS
MOWER SIND FIAGGING 5 ee ee ee
GROMING SEASON WIND FLAGGIMG ses
FLAGGING BY WINDS OURING BOTH THE GROWING SEASON
BUD MINTER SEASON eye tt
TREES AS INDICATORS OF HEAM WIND SPEED...
DESCRIPTION OF THE INDICES OF MIND EFFECTS OW TREES
SAMPLING TECHIOES «FS
MEAN WIND SPEED AND SEE DEFORMATION ©, .
SING TRES AS THDTCATORS 08 MEM wD SPEED
FREES AS INDICATORS OF SEVERE MIND OR ICE DAMAGE .
CORBIN
WREBUICES
Baer oF rrcmes
igure
mmber
a.
do
a.
ro
ne
A vind-flagged Douglas-£i2.
Wind direction dn the Uhiteface Hountalne of Hew York.
inferred fron flagged teses (Holroyd 1570).
Fiagyiny chaactertstic of wind from differaut seasons,
characteristic vind deformation shen the wind cones
from a different dlzection during the nengroving season.
‘The geographical distribution of ovuglas-fiz and
Ponderosa Pine.
‘the Griggs-Futnan Index of defornation,
‘the vechnique for determining the Deformation kati,
A typical cross section of a conifer tres growing in
vindy location.
spuntang and cross-deting core sanplos fron the windward
and Ieguara sides of the trae.
‘che nelationship hetween tha frigga-Putnam Index and
ean annual wind speed.
‘the eelationship hetwean the Deformation Ratio and mean
annual wind speed,
‘the relationship betwean the Conpraasion Ratio and mean
annual vind eped.
Wind deformation and the wind velocity that may produce
that deformation.
Lis? oP TABLES
‘the mean prediction exvors for the thres indices of wind
effects on trees
Page
1s
aa
‘BuTRODDCTTOU
‘The first and crucial step in the effective utilization of wind
power ia the selection of a epectfie location forthe wind energy con
veraion system (WECS], The magnitule of the wind resource available
at a particular site will in large part determine the syste
nonie Viability, igh wind areas are conveniently located using a
Procedure Rnova ae "Biological Wind Prospecting.”
‘hie handbook deaceibes such techaiques for using tress ax
Indicators of vind power potential and ie aimed at providing the wind
prospector with an inftial assesment of the wind pover potential.
Such methods were first weed in a vind survey by Putnam (1948) in
Yernont prior to ingtallation of the Suith-putnsa wind tuzbine at
Grandpa’ Tneh, Sovever, trees have been coed for hundreds of yoara
as rough ecological indicators of the Airaction, strength ant sever-
Ley of the winds
Subsequent sections will daseribe there techniques for using
trees in a wind survey, the role of vegetation indlestors in s{te
selection and the Limitations of these techniques.
[TREES AS THDICATORS OF PREVATLING WIND DIRECTTOH
Jn pomtaineus areas, winds are often complex and the availahle
wind dats are Limited and provide Little information on wind 4irec~
ton. One tachnique for determining the wean wind Alrection is tree
Alagsing, A flagged tree is ne dn viich the branches grow away froo
whe prevailing wind dizection, thus exhibiting a one-sided crow (see
Figure 1). Rolrayd (1970) mentions that phototropiem (directed growth
reralting from differential {liunination} nay cause branches to bend
bot the, direction of the bending {4 vaually random, Wind-Flagged
tees are distinguished from phototcopic effects, because all branches
Jn the sane meighborhoea point in a wafom directicn.
Figure 1, A wind-Elagged Douglas-fir.
Many studies have used trea defomation ax on indeator of pre
Jetterson, 1904; Laurence, 1939;
‘Thomar, 1958; and Wheava, 1964). Anong the scat anhiticous studies was
Sekiguth (1951) vho examined the direction of bending 230 pevetmon
trees in the Alaho Tan in Japan. A conpase waa used to measuce the
walling wind divertion (oavtes, 181:
Adrection of bending, Standing 40-50 paces from the bata of the trea,
Sekigutd circled the tree wne(l the dixection of flagging war deter
ined.
