Urban Forest Acoustics

181 Pages·2006·4.73 MB·English

by  Voichita Bucur

VoichitaBucur
UrbanForestAcoustics
Voichita Bucur
Urban Forest Acoustics
With109Figuresand33Tables
123
VoichitaBucur
ChargéedeRecherchesàl’INRA
Professeurhonoraire
INRA–CentredeNancy
LERMAB–Laboratoired’ÉtudesetdeRecherches
surleMatériauBois
UMRINRA1093
54280Champenoux
France
LibraryofCongressControlNumber:2005938507
ISBN-10 3-540-30783-4 SpringerBerlinHeidelbergNewYork
ISBN-13 978-3-540-30783-9 SpringerBerlinHeidelbergNewYork
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Preface
Ingeneral,treesareviewedasadmiredsymbolicindividuals,producingrecre-
ational, spiritual and emotional rejuvenation. Their lifespan can far exceed
that of humans. Planting a tree is a singular act of faith in the future, cre-
ating a legacyfor the communitymembers whowill follow. The presence of
treesinanurbanareahasbeenarealityforseveralcenturies.Beautifultrees
in urban plazas are synonymous with a high sense of community and civic
pride.Treessignificantlyenhancethelandscapingandappearanceofthebuilt
environment.
Citytreesimproveseveralarchitecturalandengineeringfunctions,provid-
ingagreeninfrastructureforcommunities.Treescreateafriendlierenviron-
mentforwalking,ridingbikesandworking,byreducingglareandsoftening
harshtrafficsoundsandconcreteviews.Treesenhancetheviewinginurban
areas of a variety of birds and small animals, such as squirrels. They are of
extreme importance to the functioning of many different ecosystems. Trees
plantedintherightplacearoundbuildingscanimproveairconditioningand
heatingcostsbyprovidingshadeorbyaffectingwindspeedordirection.Ever-
greentreeswithdense,persistentneedlescanbeusedtoprovideawindbreak,
whiledeciduoustreesallowthesuntowarmahouseinwinter.Themorecom-
pactthebranchesandfoliageofagroupoftrees,thegreatertheirinfluenceas
awindbreak.Ithasbeenshownthattreesareabletoremovepollutantsfrom
the air; and they are seen as an important potential resource for removing
greenhousegassesfromtheatmosphere.Treescontributetotheprotectionof
the environment and public health, providing economic and social benefits,
encouragingpositivesocialinteraction.
Inamodernconcept,urbanforestreferstoalltreesandvegetationinurban
andsuburbanareas.
Mymotivationforwritingthisbookcomesfromthefrequentlyaskedques-
tions about urban environmental integrity, related namely to noise, climate,
airandwaterquality.
Thisbookisstructuredinninechapters.Asusualthefirstchapter“Intro-
duction”relatestheconceptoftheurbantreeincontrasttotheforesttreeand
givesashortdescriptionofthedendrologicalcharacteristicsofdifferenttrees
intheurbanenvironment.Thesecondchapteris“NoiseinForest”andrefers
tosoundpropagationinforestandthefactorsaffectingthispropagation.The
VI Preface
equipmentforinsitunoisemeasurementispresented.Thethirdchapterintro-
ducesacousticalsensorsforthemeasurementoftreecharacteristics(diameter,
height,mechanicalandgeneticcharacteristics).Chapter4isdevotedtonoise
attenuationwithplants,settingasidegroundattenuation,scatteringbytrees,
foliage,trunksand branches. Thelastsectionof thischapter referstorever-
beration and attenuation in a forest stand. Chapter 5 depicts a very current
subject,namely,protectionagainsttrafficnoisefromhighways,railwaysand
aircraft. Chapter 6 – noise abatement and dwellings in urban and suburban
areas–underlinesthenecessitytotakeintoconsiderationthemeaningsofthe
soundscape,whichareenvironmental,historicalorcultural.Thepracticalap-
plicationofthisconceptproducessoundmapsforurbanplanning.Apositive
impression on the urban soundscape is produced by large vegetation areas,
beltsoftrees,publicgardensandparks.Chapter7offersabriefdiscussionon
therelationshipsbetweennoise,animals,insectsandtreesand,ofcourse,the
acousticmethodsforthedetectionofthepresenceofthesebiologicalagents
in different stages of development. Chapter 8 – fire control with acoustical
methods–brieflydescribesthepotential ofacousticsin forestfiredetection
andcontrol.Finally,itseemsappropriatetoendthisbook(Chap.9)withsome
considerationsabouteconomicaspectsrelatedtothevalueofurbantrees.
Acknowledgements
First of all I wish to acknowledge the National Institute for Agricultural Re-
search(INRAFrance)ForestryResearchCenterinNancy–Champenoux,and
the University Henri Poincaré, Nancy 1, Faculty of Science, Wood Research
Laboratory,forprovidingfacilitiesforwritingthisbook.
Iamindebtedtodifferentorganizationsandindividualscitedinthisbook
forpermissiontoreproducefiguresandtables.Inmybibliographicresearch,
I was assisted by the kind collaboration of helpers at various libraries in
France, such as the library of the University “Henri Poincaré” in Nancy –
Marie Annick Bruthiaux, the library of “Ecole Nationale des Eaux et Forêts
deNancy–MarieJeanneLionnet,DavidGasparottoandBrunoSpandonide,
while he was a student at the University Paris Sorbonne. I am very much
indebted to Professor Helmut Resch and to David Gasparotto for comments
thatimprovedthefinalmanuscriptofthisbook.AlsoIwishtoacknowledge
mycolleaguesDrLaurentChrusciel,DrStéphaneDumarcay,thePhDstudents
YoucefIrmouliandAnthonyDufourandoursecretariesCorinneCourtehoux
andCatherineAntoni,foreverydayassistancewiththeelectronicformofthe
manuscript.ThanksareduetomysisterDespinaSpandonideforcontinuous
andenthusiasticencouragementduringthewritingthisbook.Lastbutnotleast
I wish to acknowledge Constantin Spandonide for his generosity, spending
manyhoursinpreparingthefiguresforthisbook.
Preface VII
Finally,Iwishtoexpressmysinceregratitudeandadmirationtothestaffof
SpringerVerlagwhileworkingwithmeforthefinalversionofthemanuscript
of this book, for the pleasant and enjoyable professional moments we spent
togetherviathemoderncommunicationmedia.
Champenoux,January2006 VoichitaBucur
Contents
1 Introduction 1
2 NoiseinUrbanForest 7
2.1 SoundPropagation.............................................................. 8
2.1.1 DefinitionsandTheoreticalConsiderations................... 8
2.1.2 FactorsAffectingSoundPropagation............................ 14
2.2 EquipmentforNoiseMeasurement........................................ 15
2.2.1 InstrumentationandNoiseSources.............................. 15
2.2.2 MeasurementInSitu.................................................. 18
2.3 Summary........................................................................... 24
3 TreeCharacteristicsandAcousticSensors 27
3.1 MorphologicalCharacteristics.............................................. 27
3.2 MechanicalCharacteristics................................................... 29
3.2.1 DevicesandInstrumentation...................................... 30
3.2.2 MechanicalCharacteristicsofStandingTrees ................ 32
3.2.3 DetectionofInternalDefectsinStandingTrees.............. 32
3.3 GenotypicCharacteristics.................................................... 38
3.4 SylviculturalPractices.......................................................... 39
3.5 Summary........................................................................... 42
4 NoiseAttenuationwithPlantMaterial 43
4.1 PhysicalAspectsofNoiseAttenuationbyVegetation................. 43
4.2 GroundAttenuation ............................................................ 45
4.3 ScatteringbyTrees .............................................................. 52
4.3.1 ScatteringbyStems.................................................... 55
4.3.2 ScatteringbyCanopyandFoliage................................. 64
4.3.3 ReverberationinaForestStand................................... 92
4.3.4 AtmosphericConditions............................................. 97
4.4 SoundScatteringbyBarriers.................................................101
4.4.1 PsychologicalEffect...................................................101
4.4.2 SolidBarriersWithoutVegetation................................102
4.4.3 SolidBarrierswithVegetation.....................................105
4.5 Summary...........................................................................109
X Contents
5 TrafficNoiseAbatement 111
5.1 RoadTrafficNoise...............................................................114
5.2 RailTransportationNoise.....................................................121
5.3 AircraftNoise.....................................................................125
5.4 Summary...........................................................................127
6 NoiseAbatementandDwellings 129
6.1 UrbanArea ........................................................................129
6.2 SuburbanArea....................................................................132
6.3 Summary...........................................................................138
7 Noise,BirdsandInsectsinUrbanForest
Environment 139
7.1 BirdAcousticCommunicationinForestEnvironment..............141
7.2 DetectionofTermiteInfestationinUrbanTrees.......................143
7.3 Summary...........................................................................145
8 AcousticsforFireControlinForest 147
9 EconomicAspects 151
Annex1–Symbols 155
Annex2–SomeTheoreticalConsiderations 159
Annex3–FrequencyWeighting 161
Annex4–Standards 163
Annex5–Units 165
References 167
SubjectIndex 177
1
Introduction
Treesareanacceptedpresenceintheurbanlandscapeasindividualsinstreets,
parksandgardensorascomponentsofwoodlandsas“relics”survivingfrom
forestbeforeurbanization,orasplantedandspontaneousregeneratedblocks
onderelictsites.Thesetreesarelabeledurbantreesincontrasttoforesttrees.
TheconceptofurbanforestrywasdevelopedfirstinCanada,duringthe1960s,
andwasdefinedasapracticeproposingaglobalapproachoftreemanagement
withaviewtointegrationwithurbanactivityandpopulation.
In planning housing development in urban and suburban areas, a major
challengeistomanagethenativeforesttreesaswellasexotictrees.Because
of the urban environment, trees could decline (Fig. 1.1), changing their size
and silhouette, while at the same time being (from the pathological point of
view)soundtrees.Goodselectioncriteriashouldbeusedwhenretainingtrees
on a specific site, determined by urban morphology. Generally, the criteria
usedfortheselectionandplantingofurbantreesare:thegrowthrequirement
of each species as described by sylvicultural practice and specific features
evaluated for individual trees and stands, having in mind that trees are very
long-livedindividuals(300,900or2000years)ifair,water,mineralsfromthe
soilandsunlightaresupplied.ThepolicyoftheGreenAreasandEnvironment
Departmentsinmanycitiesintheworldistopreserveanddevelopthegreen
heritages which have an important social, aesthetic, cultural, educational or
climatic role. The need to inform and instruct people about various aspects
of environmental protection is generally accepted today. The management
of green urban areas requires a wider political,administrative and technical
approach (Council of Europe 2004). Selection of species and technological
innovations(containergrowntechniques,automaticwatering,etc.)arecrucial
issuesintreerenewalpolitics.
Accordingtothebotanicalsystemofclassification,treesfallintotwogroups:
(a)coniferous,knownasevergreens,needle-leafedtreesorsoftwoodsand(b)
deciduous,knownasbroad-leafedtreesorhardwoods.Maturesoftwoodshave
astraightcentraltrunk,withsidebrancheswhichspreadtoformaconicalor
columnarcrown.Theformofthehardwoodshasabroadroundedcrownwith
long branches. As a guide to general appearance, tree silhouettes are given
in Fig. 1.2. For tree identification, botanists use the scientific name which
consists basically of two terms: the generic name (genus) and the specific