給排水科學與工程專業(yè)英語版本教材

CONTENTS

PartOneIntroduction1

Unit1HydrologicCycle1

ImportantWordsandExpressions3

Notes4

Exercises4

ReadingMaterialA6

Notes8

ReadingMaterialB9

Notes11

Unit2WaterLegislationandRegulation12

ImportentWordsandExpressions14

Notes15

Exercises15

ReadingMaterialA17

Notes19

ReadingMaterialB20

Notes22

Unit3AnalyticalTechniqueandMethodology24

ImportantWordsandExpressions26

Notes27

Exercises27

ReadingMaterialA29

Notes31

ReadingMaterialB32

Notes34

PartTwoWaterSupplyandSewerageSystem35

Unit4WaterSupplySystem35

ImportantWordsandExpressions37

Notes37

Exercises38

ReadingMaterialA40

Notes42

ReadingMaterialB43

Notes45

Unit5WastewaterCollectionandSewerageSystemDesign46

ImportantWordsandExpressions49

Notes50

Exercises50

ReadingMaterialA52

Notes55

ReadingMaterialB56

Notes58

Unit6StormwaterCollectionandSewerDesign59

ImportantWordsandExpressions62

Notes62

Exercises62

ReadingMaterialA64

Notes67

ReadingMaterialB68

Notes71

Unit7PumpsandPumpingStations72

ImportantWordsandExpressions75

Notes76

Exercises76

ReadingMaterialA78

Notes80

ReadingMaterialB81

Notes84

PartThreePhysical-ChemicalTreatmentProcess85

Unit8CoagulationandFlocculation85

ImportantWordsandExpressions88

Notes89

Exercises89

ReadingMaterialA91

Notes94

ReadingMaterialB95

Notes98

Unit9Sedimentation99

ImportantWordsandExpressions錯誤!未定義書簽。

Notes錯誤!未定義書簽。

Exercise錯誤!未定義書簽。

ReadingMaterialA錯誤!未定義書簽。

Notes錯誤!未定義書簽。

ReadingMaterialB錯誤!未定義書簽。

Notes錯誤!未定義書簽。

Unit10Filtration113

ImportantWordsandExpressions115

Notes:116

Exercises116

ReadingMaterialA118

Notes121

ReadingMaterialB123

Notes126

Unit11ChemicalOxidation127

ImportantWordsandExpressions131

Notes132

Exercises132

ReadingMaterialA134

Notes137

ReadingMaterialB138

Notes141

Unit12Adsorption142

ImportantWordsandExpressions145

Notes146

Exercises147

ReadingMaterialA149

Notes152

ReadingMaterialB153

Notes156

Unit13MembraneFiltrationProcesses157

ImportentWordsandExpressions159

Notes160

Exercises161

ReadingMaterialA163

Notes165

ReadingMaterialB166

Notes168

PartFourBiologicalTreatmentProcess169

Unit14ActivatedSludgeProcess169

ImportantWordsandExpressions171

Notes172

Exercises172

ReadingMaterialA174

Notes176

ReadingMaterialB177

Notes179

Unit15AttachedGrowthBiologicalTreatmentProcess180

ImportantWordsandExpressions182

Notes183

ReadingMaterialA185

Notes187

ReadingMaterialB188

Notes191

Unit16AnaerobicBiologicalTreatment192

ImportantWordsandExpressions195

Notes196

Exercises196

ReadingMaterialA198

Notes200

ReadingMaterialB201

Notes203

PartFiveSludgeTreatment,ReuseandDisposal204

Unit17Thickening204

ImportantWordsandExpressions206

Notes207

Exercises207

ReadingMaterialA209

Notes212

ReadingMaterialB213

Notes215

Unit18AnaerobicDigestion216

ImportantWordsandExpressions219

Notes219

Exercises220

ReadingMaterialA222

Notes225

ReadingMaterialB226

Notes229

Unit19Dewatering230

ImportantWordsandExpressions錯誤!未定義書簽。

Notes錯誤!未定義書簽。

Exercises錯誤!未定義書簽。

ReadingMaterialA錯誤!未定義書簽。

Notes錯誤!未定義書簽。

ReadingMaterialB錯誤!未定義書簽。

Notes錯誤!未定義書簽。

Unit20SludgeUtilizationandDisposal244

ImportantWordsandExpressions246

Notes246

Exercises247

ReadingMaterialA249

Notes251

ReadingMaterialB252

Notes254

PartsixBuildingWaterSupplyandDrainage255

Unit21ColdWaterSupply255

ImportantWordsandExpressions257

Notes258

Exercises258

ReadingMaterialA260

Notes262

ReadingMaterialB263

Notes266

Unit22Building-DrainageSystem267

ImportantWordsandExpressions269

Notes269

Exercises269

ReadingMaterialA271

Notes273

ReadingMaterialB274

Notes276

Unit23Fire-FightingSystems278

ImportantWordsandExpressions281

Notes281

Exercises282

ReadingMaterialA283

Notes284

ReadingMaterialB285

Notes286

References錯誤!未定義書簽。

PartOneIntroduction

Unit1HydrologicCycle

Thehydrologiccycle,alsoknownasthewatercycleorH2Ocycle,describesthe

continuousmovementofwateron,aboveandbelowthesurfaceoftheearth.Watercan

changestatesamongliquid,vapour,andsolidatvariousplacesinthewatercycle.Although

thebalanceofwateronEarthremainsfairlyconstantovertime,individualwatermolecules

cancomeandgo,inandoutoftheatmosphere.Thewatermovesfromonereservoirto

another,suchasfromrivertoocean,orfromtheoceantotheatmosphere,bythephysical

processesofevaporation,condensation,precipitation,infiltration,runoff,andsubsurfaceflow.

⑴Insodoing,thewatergoesthroughdifferentphases:liquid,solid,andgas.

Thewatercycleinvolvestheexchangeofheatenergy,whichleadstotemperature

changes.Forinstance,intheprocessofevaporation,watertakesupenergyfromthe

surroundingsandcoolstheenvironment.Conversely,intheprocessofcondensation,water

releasesenergytoitssurroundings,warmingtheenvironment.Thewatercyclefigures

significantlyinthemaintenanceoflifeandecosystemsonEarth.Evenaswaterineach

reservoirplaysanimportantrole,thewatercyclebringsaddedsignificancetothepresenceof

wateronourplanet.Bytransferringwaterfromonereservoirtoanother,thewatercycle

purifieswater,replenishesthelandwithfreshwater,andtransportsmineralstodifferentparts

oftheglobe.f2lItisalsoinvolvedinreshapingthegeologicalfeaturesoftheEarth,through

suchprocessesaserosionandsedimentation.Inaddition,asthewatercyclealsoinvolvesheat

exchange,itexertsaninfluenceonclimateaswell.

Thesun,whichdrivesthewatercycle,heatswaterinoceansandseas.Waterevaporates

aswatervaporintotheair.Iceandsnowcansublimatedirectlyintowatervapor.

Evapotranspirationiswatertranspiredfromplantsandevaporatedfromthesoil.Risingair

currentstakethevaporupintotheatmospherewherecoolertemperaturescauseittocondense

intoclouds.Aircurrentsmovewatervaporaroundtheglobe,cloudparticlescollide,grow,

andfalloutoftheskyasprecipitation.Someprecipitationfallsassnoworhail,sleet,andcan

accumulateasicecapsandglaciers,whichcanstorefrozenwaterforthousandsofyears.

Mostwaterfallsbackintotheoceansorontolandasrain,wherethewaterflowsoverthe

groundassurfacerunoff.Aportionofrunoffentersriversinvalleysinthelandscape,with

streamflowmovingwatertowardstheoceans.Runoffandgroundwaterarestoredas

freshwaterinlakes.Notallrunoffflowsintorivers,muchofitsoaksintothegroundas

infiltration.Somewaterinfiltratesdeepintothegroundandreplenishesaquifers,whichstore

freshwaterforlongperiodsoftime.Someinfiltrationstaysclosetothelandsurfaceandcan

seepbackintosurface-waterbodies(andtheocean)asgroundwaterdischarge.Some

groundwaterfindsopeningsinthelandsurfaceandcomesoutasfreshwatersprings.Over

time,thewaterreturnstotheocean,whereourwatercyclestarted.

Theresidencetimeofareservoirwithinthehydrologiccycleistheaveragetimeawater

moleculewillspendinthatreseroir.Itisameasureoftheaverageageofthewaterinthat

reservoir.Groundwatercanspendover10,000yearsbeneathEarth'ssurfacebeforeleaving.

Particularlyoldgroundwateriscalledfossilwater.Waterstoredinthesoilremainstherevery

briefly,becauseitisspreadthinlyacrosstheEarth,andisreadilylostbyevaporation,

transpiration,streamflow,orgroundwaterrecharge.131Afterevaporating,theresidencetime

intheatmosphereisabout9daysbeforecondensingandfallingtotheEarthasprecipitation.

Themajoricesheet-AntarcticaandGreenland-storeiceareforverylongperiods.Icefrom

Antarcticahasbeenreliablydatedto800,000yearsbeforepresent,thoughtheaverage

residencetimeisshorter.

Inhydrology,residencetimescanbeestimatedintwoways.Themorecommonmethod

reliesontheprincipleofconservationofmassandassumestheamountofwaterinagiven

reservoirisroughlyconstant.Withthismethod,residencetimesareestimatedbydividingthe

volumeofthereservoirbytheratebywhichwatereitherentersorexitsthereservoir.

Conceptually,thisisequivalenttotiminghowlongitwouldtakethereservoirtobecome

filledfromemptyifnowaterweretoleave(orhowlongitwouldtakethereservoirtoempty

fromfullifnowaterweretoenter).Analternativemethodtoestimateresidencetimes,which

isgaininginpopularityfordatinggroundwater,istheuseofisotopictechniques.Thisisdone

inthesubfieldofisotopehydrology.

Humanactivitiesthatalterthewatercycleinclude:

?Agriculture

?Industry

?Alterationofthechemicalcompositionoftheatmosphere

?Constructionofdams

?Deforestationandafforestation

?Removalofgroundwaterfromwells

?Waterabstractionfromrivers

?Urbanization

Effectsonclimate:Thewatercycleispoweredfromsolarenergy.86%oftheglobal

evaporationoccursfromtheoceans,reducingtheirtemperaturebyevaporativecooling.

Withoutthecooling,theeffectofevaporationonthegreenhouseeffectwouldleadtoamuch

highersurfacetemperatureof67℃(153°F),andawarmerplanet.

Aquiferdrawdownoroverdraftingandthepumpingoffossilwaterincreasesthetotal

amountofwaterinthehydrospherethatissubjecttotranspirationandevaporationthereby

causingaccretioninwatervapourandcloudcoverwhicharetheprimaryabsorbersofinfrared

radiationintheEarth'satmosphere.141Addingwatertothesystemhasaforcingeffectonthe

wholeearthsystem,anaccurateestimateofwhichhydrogeologicalfactisyettobequantified.

ImportantWordsandExpressions

hydrology口加乂］口口_1人口口口］n.水文學，水文地理學

reservoirn,蓄水池；貯液器；儲藏；蓄積

evaporation[AD_?/□□□□□□□□□n.蒸發(fā)，發(fā)散；消失

condensation[口口1口口11口口工口口卬口口卬口]n.冷凝；冷凝液；凝結(jié)的水珠；節(jié)略

precipitation[工口口工⑷口_卬口口]n.匆促；沉淀；(雨等)降落；某地區(qū)降雨等的量

figure[D^DD]n.數(shù)字；算術(shù)；圖解；輪廓vt.估計；推測；認為

replenish□工DY如口□□口vt.補充；重新裝滿；把...裝滿；

sedimentation[□山口口在口口_□□口口口]n.沉淀，沉降

evaportranspirationn.作物騰發(fā)量

sublimatePJ]$￡]+□_]n.升華物vt.(使某物質(zhì))升華；使凈化；純化

infiltration[口口口村內(nèi)~山口口口口]n.滲透

residencetime停留時間

deforestation[□□□□□＞工工口一□口口口]n,采伐森林，森林開伐

afforestation[口口/?.上□!?□□□□□□n.造林，造林地區(qū)

叫uifer[□?.?口工乂1口n.地下蓄水層，砂石含水層

Notes

[1]由于蒸發(fā)、凝結(jié)、降水、入滲、徑流、潛流等物理過程，水從一個蓄水池到另一個,

比如從河流到海洋，從海洋到大氣。

[2]通過水從一個蓄水池到另一個，水循環(huán)凈化了水，為陸地補充了淡水，把礦物質(zhì)運

送到地球不同的部位。

[3]土壤中儲存的水停留很短暫，因為土壤水薄薄的分布在地表，通過蒸發(fā)、蒸騰、河

川徑流和地下水補給而容易消失。

[4]地下水位降低或者超采以及化石水的抽取增加了水圈中水的總量，水圈中的水易于

蒸騰和蒸發(fā)，從而產(chǎn)生水蒸氣以及云量的堆積，這些是地球大氣中紅外輻射最主要的吸

收體。

Exercises

1.AnsweringthefollowingquestionsinEnglishaccordingtothetext:

(1)Howmanyphysicalprocesseshappenedinhydrologiccycleaccordingtothetext?

(2)Trytoexplainthemethodofestimatingtheresidencetimeofthewater.

2.Usingthefollowingeachwordtomakeupthesentences,respectively:

(1)Hydrologiccycle

(2)subsurfaceflow

(3)runoff

(4)residencetime

(5)conservationofmass

3.PutthefollowingEnglishintoChinese:

(1)Groundwaterisanimportantdirectsourceofsupplythatistappedbywells,aswell

asasignificantindirectsourcesincesurfacestreamsareoftensuppliedbysubterraneanwater.

Nearthesurfaceoftheearth,inthezoneofaeration,soilporespacescontainbothairand

water.Thiszone,whichmayhavezerothicknessinswamplandsandbeseveralhundredfeet

thickinmountainousregions,containsthreetypesofmoisture.Afterastorm,gravitywateris

intransitthroughthelargersoilporespaces.Capillarywaterisdrawnsmallporespacesby

capillaryactionandisavailableforplantuptake.Hygroscopicmoistureisheldinplaceby

molecularforcesduringallexceptthedriestclimaticconditions.Moisturefromthezoneof

aerationcannotbetappedasawatersupplysource.

(2)Inthezoneofsaturation,locatedbelowthezoneofaeration,thesoilporesarefilled

withwater,andthisiswhatwecallgroundwater.Astratumthatcontainsasubstantialamount

ofgroundwateriscalledanaquifer.Atthesurfacebetweenthetwozones,calledthewater

tableorphreaticsurface,thehydrostaticpressureinthegroundwaterisequaltothe

atmospherepressure.Anaquifermayextendtogreatdepths,butbecausetheweightof

overburdenmaterialgenerallyclosesporespaces,littlewaterisfoundatdepthsgreaterthan

600m(1200ft).Theamountofwaterthatwilldrainfreelyfromanaquiferisknownas

specificyield.

4.PutthefollowingChineseintoEnglish:

(1)水循環(huán)

(2)蒸發(fā)

(3)停留時間

(4)地球上的水不是靜止的，而是不斷運動變化和相互交換的。

(5)在太陽輻射和地心吸引力的作用下，地球上各種狀態(tài)的水從海洋面、江河面.、

湖沼面、陸地面和動植物表面蒸發(fā)、蒸騰變成水汽，上升于空中，或停留在空中，或

被氣流帶到其他地區(qū)，在適當條件下凝結(jié)，然后以降水形式落到海洋面或陸地表面。

ReadingMaterialA

TheWaterBalance

Inhydrology,awaterbalanceequationcanbeusedtodescribetheflowofwaterinand

outofasystem.Asystemcanbeoneofseveralhydrologicaldomains,suchasacolumnof

soiloradrainagebasin.Waterbalancecanalsorefertothewaysinwhichanorganism

maintainswaterindryorhotconditions.Itisoftendiscussedinreferencetoplantsor

arthropods,whichhaveavarietyofwaterretentionmechanisms,includingalipidwaxy

coatingthathaslimitedpermeability.1,1

Waterbalancecalculations

Waterbalancecalculationscanhelptodetermineifadrainageareaislargeenoughorhas

therightcharacteristicstosupportapermanentpoolofwaterduringaverageorextreme

.[21

conditions.1J

Whenindoubt,awaterbalancecalculationmaybeadvisablefbrretentionpondand

wetlanddesign.Thedetailsofarigorouswaterbalancearebeyondthescopeofthismanual.

However,asimplifiedprocedureisdescribedhereinthatwillprovideanestimateofpool

viabilityandpointtotheneedfbrmorerigorousanalysis.Waterbalancecanalsobeusedto

helpestablishplantingzonesinawetlanddesign.

Basicequations

Waterbalanceisdefinedasthechangeinvolumeofthepermanentpoolresultingfrom

thetotalinflowminusthetotaloutflow(actualorpotential).Equation1-1presentsthis

calculation.

△(1-1)

where

△=deltaorchangein

V=pondvolume(ac-ft)

X=thesumof

I=Inflows(ac-ft)

O=Outflows(ac-ft)

Theinflowsconsistofrainfall,runoffandbaseflowintothepond.Theoutflowsconsist

ofinfiltration,evaporation,evapotranspiration,andsurfaceoverflowoutofthepondor

wetland.Equation1-1canbeexpandedtoreflectthesefactors,asshowninEquation1-2.

KeyvariablesinEquation1-2arediscussedindetailbelowtheequation.

AV=PA+R0+BrlA-EA-EtA-Of(1-2)

where

P=precipitation(ft)

A=areaofpond(ac)

Ro=runoff(ac-ft)

Bf=baseflow(ac-ft)

I=infiltration(ft)

E=evaporation(ft)

Et=evapotranspiration(ft)

Of=overflow(ac-ft)

Rainfall(P)MonthlyrainfallvaluescanbeobtainedfromtheNationalWeatherService

climatologyat/mrx/climat.htm.Monthlyvaluesarecommonly

usedforcalculationsofvaluesoveraseason.Rainfallisthenthedirectamountthatfallson

thepondsurfacefortheperiodinquestion.Whenmultipliedbythepondsurfacearea(in

acres)itbecomesacre-feetofvolume.

Runoff(Ro)Runoffisequivalenttotherainfallfortheperiodtimestheefficiencyof

thewatershed,whichisequaltotheratioofrunofftorainfall(Q/P).Inlieuofgage

information,Q/Pcanbeestimatedoneofseveralways.Thebestmethodwouldbetoperform

long-termsimulationmodelingusingrainfallrecordsandawatershedmodel.

Baseflow(B)Moststormwaterpondsandwetlandshavelittle,ifany,baseflow,as

theyarerarelyplacedacrossperennialstreams.Ifsoplaced,baseflowmustbeestimatedfrom

observationorthroughtheoreticalestimates.Methodsofestimationandbaseflowseparation

canbefoundinmosthydrologytextbooks.

Infiltration(I)Infiltrationisaverycomplexsubjectandcannotbecoveredindetailhere.

Theamountofinfiltrationdependsonsoils,watertabledepth,rocklayers,surface

disturbance,thepresenceorabsenceofalinerinthepond,andotherfactors.

Evaporation(E)Evaporationisfromanopenlakewatersurface.Evaporationrates

aredependentondifferencesinvaporpressure,which,inturn,dependontemperature,wind,

atmosphericpressure,waterpurity,andshapeanddepthofthepond.⑶Itisestimatedor

measuredinanumberofways,whichcanbefoundinmosthydrologytextbooks.Pan

evaporationmethodsarealsoused,thoughtherearenolongerpanevaporationsitesactivein

KnoxCounty.FormerlypanevaporationmethodswereutilizedattheKnoxvilleExperiment

Station.

Evapotranspiration(Et)Evapotranspirationconsistsofthecombinationofevaporation

andtranspirationbyplants.TheestimationofEtforcropsiswelldocumentedandhasbecome

standardpractice.However,theestimatingmethodsforwetlandsarenotdocumented,norare

thereconsistentstudiestoassistthedesignerinestimatingthewetlandplantdemandonwater

volumes.LiteraturevaluesforvariousplacesintheUnitedStatesvaryaroundthefreewater

surfacelakeevaporationvalues.EstimatingEtonlybecomesimportantwhenwetlandsare

beingdesignedandemergentvegetationcoversasignificantportionofthepondsurface.In

thesecasesconservativeestimatesoflakeevaporationshouldbecomparedtocrop-basedEt

estimatesandadecisionmade.Crop-basedEtestimatescanbeobtainedfromtypical

hydrologytextbooksorfromthewebsitesmentionedabove.Avalueofzeroshallbeassumed

forEtunlessthewetlanddesigndictatesotherwise.

Overflow(Of)Overflowisconsideredasexcessrunoff,andinwaterbalancedesignis

eithernotconsideredsincetheconcernisforaverageprecipitationvalues,orisconsidered

lostforallvolumesabovethemaximumpondstorage.|4|Obviously,forlong-termsimulations

ofrainfall-runoff,largestormswouldplayanimportantpartinponddesign.

Notes

[1]關(guān)于植物或者節(jié)肢動物的水平衡也經(jīng)常被論及，他們有多種水保持機制，包括有限

滲透性的脂蠟質(zhì)覆蓋層。

[2]水平衡的計算可以幫助確定一個排水區(qū)域是否足夠大或者是否能夠在平常或極端條

件下支撐一個永久的水池。

[3]蒸發(fā)速率取決于蒸汽壓的不同，而蒸汽壓依次取決于溫度、風、大氣壓力、水的純

度、水池的形狀和深度。

[4]溢流被認作多余的徑流，在水平衡設(shè)計中，要么因為關(guān)心的是平均降水量，不被考

慮，要么是被作為超出最大池容量的所有容積損失。

ReadingMaterialB

WaterResourcesProtection

Waterresourcesinvolvesurfacewater,waterbelowgroundandwaterthatfallsfromthe

sky.Protectinggroundwaterresourceswillbeamajorchallengeincomingyearsbecauseof

increaseddevelopmentpressuresandwaterdemands,climatechange,andtheuncertaintyof

surfacewateravailability.

Groundwaterisahiddenresource,andtolearnmoreaboutthisresourcewehavetorely

onmorethanourfivesenses.Fortunately,wedonothavetoresorttodowsingtogainabetter

understandingofgroundwater.Groundwatermappingandmodelinghelpsusmakedecisions

abouthowtomanagewaterresourcesintermsofbothwaterqualityandwaterquantity.111

Groundwaterisoneofthenation'smostcriticalnaturalresources.ltisthelargestsource

ofusablewaterstorageintheUnitedStates,containingmorewaterthanallreservoirsand

lakescombined,excludingtheGreatLakes.Accordingtoscientists,anestimated1million

cubicmilesofgroundwaterislocatedwithinone-halfmileofthelandsurface.Onlyavery

smallpercentageofgroundwaterisaccessibleandcanbeusedforhumanactivities.Most

citiesmeettheirneedsforwaterbywithdrawingitfromthenearestriver,lake,reservoir,but

manydependongroundwateraswell.121

WaterisalreadyinshortsupplyinmanypartsoftheUnitedStates,andthesituationis

onlygoingtogetworse.Accordingtoa1999UnitedStatesGeologicalSurvey.Groundwater

isthesourceofabout40%ofthewaterusedforpublicsupplyandprovidesdrinkingwaterfor

morethan97%oftheruralpopulationintheUnitedStates.l31Between30%and40%ofthe

waterusedfortheagriculturalindustrycomesfromgroundwater.Weneedtounderstand

groundwaterifwearegoingtocontinuetomakegooddecisionsaboutsustainablewater

resources.

Inrecentyears,peoplehavebeguntounderstandthatgroundwaterandsurfacewaterare

fundamentallyinterconnectedandareintegralcomponentsofthehydrologiccycle.

Nevertheless,mostlawsgoverninggroundwaterissuesarebasedonthisnotionthat

groundwaterandsurfacewaterhavenothingtodowitheachother.Inmostpartsofthe

country,surfacewaterisgovernedbydoctrinesofriparianlaworprior

appropriation.Groundwatertraditionallyhasbeentreatedasacommonresource,with

virtuallynorestrictionsonaccessingthewater.Ifyoucanaffordtopaysomeonetodrilla

wellandyouhappentohitwater,youcandowhateveryouwantwithit.

Theunregulatedpumpingofgroundwaterisnolongeraviableoption.Inmanypartsof

thecountry,groundwaterisbeingwithdrawnatratesthatarenosustainable,andtheresultisa

degradationofwaterqualityandquantity.14,Thewaterlevelinaquifersisbeinglowered,and

becausewekeepdiggingdeeperanddeeperwellstoaccessthewater,thewaterquantityis

furtherdepleted.Incoastalareas,intensivepumpingoffreshgroundwaterhascaused

saltwatertoseepintofreshwateraquifers.

Groundwaterisalsocriticalfortheenvironmentalhealthofrivers,wetlandsandestuaries

throughoutthecountry.Groundwaterwithdrawalscanresultinreducedflowstostreamsand

alterwetlandhydrology.Changesinstreamflowhaveimportantimplicationsfbrwaterand

floodmanagement,irrigationandplanning.

Therearehundredsofexamplesacrossthecountrywheregroundwateristhreatened.The

CaliforniaDepartmentofHealthServicesreportedin2008thatmorethan300publicsupply

sourcesandanequallylargenumberofprivatehomeownerwellswerecontaminatedand

shouldnotbeused⑸.InportionsoftheSouthwest,Northwest,andMidwest,arsenicoccers

naturallyingroundwateratlevelsthatexceeddrinkingwaterstandardsandmany

municipalitiesarenowdebatingwhethertobuildtreatmentplantsorreservoirs.Eitherwill

costhundredsofmillionsofdollars.

AccordingtotheArizonaDepartmentofEnvironmentalQuality,approximatelyone-third

ofArizonawatersystemsexceedthelevelsetfbrarsenicpoisoning.Onelong-termimpactof

the1988droughtintheMidwestisthatmanyaquiferswereoverpumpedbyfarmersseeking

tosavetheircropsandtheirwayoflife.Arkansasresidentsusegroundwatertomeet

approximately93%oftheirwaterneeds.

InmanypartsofFlorida,theexistingaquiferisnotsufficienttomeettheneedsofthe

state'sgrowingpopulationandtheneedsoftheenvironment,agriculture,andindustry.Florida

isoneoffourstatesinthecountrythatusesmoregroundwaterthansurfacewater.

TheGroundWaterProtectionCouncil(2007)hasdefinedabroadvisionofwhatitwould

taketomaintainasustainablesourceofgroundwater.Itwrotethatthenationneedsto:

Continuetoconductresearchandprovideinfbrmation-atascalethatisusefultostatesand

localentities-aboutsuchmattersasthesafe,orsustainable,yieldofaquifers(andmethodsfbr

determiningthatyield);water-usedata;anddelineatingboundariesandwaterbudgetsof

three-dimensionalwatersheds,includingscientificallybasedandcost-effectivemethodsof

quantifyinginteractionsbetweengroundwaterandsurfacewater.

Notes

[1]地下水的測繪和模型幫助我們確定在水質(zhì)和水量兩個方面怎樣管理水資源。

[2]許多城市從最近的河流、湖泊，或者水庫中抽水滿足他們的需求，但是也有很多是

依賴地下水的。

[3]依據(jù)美國1999年的地質(zhì)調(diào)查，公共供水中的40%是來自于地下水，地下水為97%

的美國農(nóng)村人口提供飲用水。

[4]國內(nèi)許多地方，地下水的抽取速度是不可持續(xù)的，結(jié)果是水質(zhì)和水量的下降。

[5]加利福尼亞衛(wèi)生服務(wù)部門2008年報告：超過300個公共供應(yīng)來源和同樣大數(shù)量的私

人水井被污染了并且不能再使用。

Unit2WaterLegislationandRegulation

Theaimofnationaldrinking-waterlawsandstandardsshouldbetoensurethatthe

consumerenjoyssafepotablewater,nottoshutdowndeficientwatersupplies.

Effectivecontrolofdrinking-waterqualityissupportedideallybyadequatelegislation,

standardsandcodesandtheirenforcement.Theprecisenatureofthelegislationineach

countrywilldependonnational,constitutionalandotherconsiderations.Itwillgenerally

outlinetheresponsibilityandauthorityofanumberofagenciesanddescribetherelationship

betweenthem,aswellasestablishbasicpolicyprinciples(e.g.,watersuppliedfor

drinking-watershouldbesafe).Thenationalregulations,adjustedasnecessary,shouldbe

applicabletoallwatersupplies.Thiswouldnormallyembodydifferentapproachesto

situationswhereformalresponsibilityfbrdrinkingwaterqualityisassignedtoadefined

entityandsituationswherecommunitymanagementprevails.111

Legislationshouldmakeprovisionfbrtheestablishmentandamendmentof

drinking-waterqualitystandardsandguidelines,aswellasfbrtheestablishmentof

regulationsforthedevelopmentandprotectionofdrinking-watersourcesa