Lucas 1-5 暴雨控制措施過(guò)程

WatershedModelingandHydrologicProcessesPrecipitation-Rain&snow

（降水—雨雪）Interception-Plantleafstorage

（截留—植物樹(shù)葉存儲(chǔ)）SurfaceRunoff-Netofinterception,notinfiltrated（地表徑流—不下滲的總截留量）Infiltration-Netofinterception,infiltrated（下滲—下滲的總截留量）Interflow(subsurfaceflow)–showsasrecessionlimb（壤中流，或潛流—可視為退水分支）Evapotranspiration(ET)-Mostofinfiltratedflow（蒸發(fā)蒸騰作用(ET)—下滲流的大部分）Recharge-RestofInfiltratedafterInterflowandET（補(bǔ)給—經(jīng)過(guò)壤中流和蒸騰后剩余的下滲部分）Groundwaterdischarge-Baseflow（排放形成的地下水水流）Source:VDEQ(2009)Virginia’sWaterResources,/vanaturally/guide/water.html

降水下滲地表徑流蒸發(fā)蒸騰地下水水流地表徑流地下水水流河流蒸發(fā)降水壤中流不飽和區(qū)土壤水（地下水）補(bǔ)給重力疏干地下水位PrecipitationandInterception

降水和截留作用Precipitationistheimportantfactoraffectingtheamountandspatialdistributionofwaterthroughawatershed降水是一個(gè)影響流域中的水空間數(shù)量分布的重要因素Interceptionistheprocesswhichmayalterthepatternandtheamountofwaterreachingthesoilsurfacebythevegetativecover截留作用可以改變水通過(guò)植被覆蓋到達(dá)土壤表面的模式和數(shù)量Factorsaffectinginterception:影響截留的因素Typeoflandcover土地覆蓋類型Extentoflandcover土地覆蓋程度Conditionoflandcover土地覆蓋條件Source:/wiki/Interception_(water)

降水樹(shù)干莖流穿透降雨樹(shù)冠截留下滲森林地面截留Infiltration

下滲作用Rainfallreachesthegroundsurfacefillsdepressions,thenentersthesoilorrunsoff.降雨到達(dá)地表填滿洼地，然后進(jìn)入土壤或流走Infiltrationistheprocesswhichrainfallentersthesoillayer下滲就是降雨進(jìn)入土層的過(guò)程Factorsaffectinginfiltration:影響下滲的因素SoilCharacteristics:SuctionHeadandSaturatedHydraulicConductivity土壤特點(diǎn)：吸入水頭和飽和的水力傳導(dǎo)率Soilsaturation:SuctionHead土壤飽和度：吸入水頭Theamountandcharacteristicsofprecipitation:intensityanddepth降水量和降水特點(diǎn)：強(qiáng)度和雨量Landcover:vegetatedvs.bare土地覆蓋：植被vs.裸露Slopeoftheland:Lessimportant土地坡度：相對(duì)次要Source:http:///hydrological_cycle/infiltration.html

降雨下滲滲漏非飽和帶地下水位SurfaceRunoff

地表徑流SurfaceRunoffistherainfallreachinggroundsurfacethatdoesnotinfiltrate.地表徑流是降雨到達(dá)地表且不下滲的部分Factorsaffectingrunoff:影響徑流的因素：SoilCharacteristics:SuctionHeadandSaturatedHydraulicConductivity.土壤特點(diǎn)：吸入水頭和飽和的水力傳導(dǎo)率。Rainfallcharacteristics:intensity,duration.降雨特點(diǎn)：強(qiáng)度，持續(xù)時(shí)間。Vegetation:Rootingdensity,roughness植被：根密度，粗糙度。Watershedcharacteristics:overlandflowtype,lengthandslope.流域特點(diǎn)：地面水流類型，長(zhǎng)度和傾斜度。Attenuatingfeatures:depressionstorage,reservoirstorage.衰減特征：洼地存儲(chǔ)，蓄水池存儲(chǔ)。Evapotranspiration

蒸發(fā)蒸騰作用Evapotranspirationistheprocessofevaporationfromsoilsandtranspirationthroughleaves.蒸發(fā)蒸騰是通過(guò)土壤蒸發(fā)和樹(shù)葉蒸騰的過(guò)程。FactorsaffectingEvapotranspiration:影響蒸發(fā)蒸騰的因素：Energyavailability

能量可用性Vaporpressure

蒸汽壓Windspeed

風(fēng)速Wateravailability

水可用性Vegetativecover

植被覆蓋Planttypeandheight

植物類型和高度Soilcharacteristicssuch

asheatcapacity,soilchemistry,andalbedo土壤特點(diǎn)如比熱容，土壤化學(xué)性質(zhì)和反射率Source:

/wiki/Evapotranspiration.蒸發(fā)蒸騰=蒸騰+蒸發(fā)蒸騰草地樹(shù)蒸發(fā)徑流地下水補(bǔ)給SoilMoistureStorage

土壤降雨貯水量Soilmoisturestorageistheamountofwaterstoredinthesoilwithintheplant’srootzone土壤降雨貯水量是土壤中植物根部區(qū)域的存水量Factorsaffectingsoilmoisturestorage:影響土壤降雨貯水量的因素：Soiltexture土壤結(jié)構(gòu)Croprootingdepth作物扎根深度WaterBalanceinsoilcanbesimilartoreservoirstorage土壤中的水平衡可以類比于儲(chǔ)水池貯水量Infiltrationincreasesmoisture下滲提高濕度Evapotranspirationremovesmoistureupward蒸發(fā)蒸騰向上帶走濕度Interflowremovesmoisturelaterally壤中流橫向帶走濕度Drainagetogroundwaterremovesmoisturedownward排放進(jìn)入地下水向下帶走濕度Source:Allen,R.G.,Pereira,L.S.,Raes,D.,andSmith,M.(1998)CropEvapotranspiration:GuidelinesforComputingCropWaterRequirements.UnitedNationsFoodandAgriculturalOrganization(FAO),IrrigationandDrainagePaper56,Rome,Italy.

蒸發(fā)蒸騰雨灌溉徑流毛細(xì)上升深層滲透飽和田間保水量閾值萎蔫點(diǎn)虧水Groundwater

地下水Groundwateristhepermanentlysaturatedzoneunderthevadosezone.地下水是處于包氣帶下面的永久飽和帶Rechargedfromvadosezoneasnetinfiltrationafterevapotranspirationandinterflow補(bǔ)給來(lái)自包氣帶的經(jīng)過(guò)蒸發(fā)蒸騰和壤中流之后的下滲總量Dischargesasbaseflowintostreams,maintainingflowbetweenevents.隨著水流進(jìn)入河流排放，保持著兩者之間的水流。Factorsaffectinggroundwaterflowmovement:影響地下水流動(dòng)的因素：Topography地形學(xué)Subsoil/Bedrockcharacteristics下層土/基巖特點(diǎn)Riparianzoneevapotranspiration河岸地區(qū)的蒸發(fā)蒸騰Source:USGS-GROUNDWATERATLASoftheUNITEDSTATES:Delaware,Maryland,NewJersey,NorthCarolina,Pennsylvania,Virginia,WestVirginia,HA730-L

包氣帶飽和帶毛細(xì)上升區(qū)水位地下水流動(dòng)WaterBudget

水量平衡Therelationshipbetweeninputandoutputofwaterthrougharegion.一個(gè)地區(qū)水量輸入與輸出的關(guān)系。Requiresestimatingtheamountofwaterineachcomponent.要求預(yù)測(cè)在每一個(gè)部分的水量。Requirescalculatingmovementofwaterthroughdifferentcomponents.要求計(jì)算每一個(gè)部分之間的水流動(dòng)。Keycomponentsofwaterbudget:水平衡的關(guān)鍵部分Precipitation

降水Surface-Runoff

地表徑流Evapotranspiration

蒸發(fā)蒸騰Groundwaterflow

地下水水流Changeinsurface-waterandgroundwaterstorage

地表水與地下水貯水的交換Changeinsnowandicestorage

冰貯水和雪的交換Humanwithdrawals

人類開(kāi)采Source:/watercensus/water-budgets.html

WaterBudget

水量平衡SurfaceWaterBudgets:地表水平衡：StreamflowR=SRO+SSF+B河流量R=SRO+SSF+BEvapotranspirationET=E+I+T蒸發(fā)蒸騰ET=E+I+TPrecipitationP=ET+R降水P=ET+R

Where:StreamFlow(R),SurfaceRunoff(SR0),Subsurfacefloworinterflow(SSF),BaseFlow(B),Evapotranspiration(ET),Evaporation(E),Transpiration(T),Interception(I),Precipitation(P).其中：河流流量(R)，地表徑流(SRO)，地下徑流流或壤中流(SSF)，基流(B)，蒸發(fā)蒸騰(ET)，蒸發(fā)(E)，蒸騰(T)，截留(I)，降水(P)。Infiltration-Mechanisms

下滲—機(jī)制EffectsofVegetation(Ralston,2004,Rachmanetal2004).植被作用（羅爾斯頓，2004，拉赫曼等人，2004）Vegetationrestores/enhancesinfiltrationrates.Uptoseveralordersofmagnitudehigher.植被恢復(fù)/提高下滲速率。可提高幾個(gè)量級(jí)。Rootspenetrateconfininglayers,openupsoilstructure.Rootturnoverformsmacropores.根穿透隔水層，打開(kāi)土壤結(jié)構(gòu)。根翻過(guò)來(lái)形成大孔隙。Nativegrassesincropsinfiltrateanorderofmagnitudehigherthanadjacentcroppedarea.作物中天然草地的下滲比周邊作物區(qū)下滲大一個(gè)量級(jí)。Evenindepositionsetting,infiltrationoutsidethegrasseswerehalfthatofcrops.即使在沉積作用的設(shè)定下，草地以外的作物的下滲是草地的一半。EffectsofOrganicMatter(SaxtonandRawls,2004).有機(jī)物質(zhì)的作用（薩克斯頓和羅爾斯，2004）。Organicmatter(OM)contentsubstantiallyincreasesinfiltrationrates.有機(jī)物質(zhì)(OM)含量極大地提高下滲速率Primarilyduetodecreasedbulkdensity.SoilshighinOMcannotbecompacted主要因?yàn)轶w密度的降低。高有機(jī)物質(zhì)含量的土壤無(wú)法有緊密的狀態(tài)Intactmineraltopsoiltypically1-2%OM,butsubstantiallylessifdisturbed.完整的礦物表土一般含有1-2%有機(jī)物質(zhì)，但一旦被擾亂，會(huì)極大的降低。SoilscanbeamendedtoanOMcontentof5-10%(w/w).土地可以修復(fù)成含有5-10%(重量/重量)的有機(jī)物質(zhì)含量。OMincreasesfieldcapacityinsandysoilsbyapproximately10%.有機(jī)物質(zhì)提高場(chǎng)地約10%的砂土能力含量。OMalsopromotesthemicrobialcommunity,contributingtosoilaggregateformation.有機(jī)物質(zhì)也可以增進(jìn)微生物群落，為土壤聚集形成做貢獻(xiàn)。Infiltration-Mechanisms

下滲—機(jī)制EffectsofCompaction(Pitt1987,OCSCD,2001,SaxtonandRawls,2004).緊密結(jié)構(gòu)的作用（皮特1987，海洋郡水土保護(hù)區(qū)，2001，薩克斯頓和羅爾斯，2004）Compactioncansubstantiallyreduceinfiltrationrates.緊密結(jié)構(gòu)可以極大地減少下滲速率。Especiallyinsandysoils,whererateshavebeenshowntodeclinefromHSG“A”to“D”.特別是在砂土中，速率被證明可以從HSG的A降到DThisisprimarilyduetoincreasedbulkdensity.這主要是因?yàn)轶w密度的提高。Compactiongreatlyinhibitsthegrowthofplants,sincerootscannotextendthroughthesoil.緊密結(jié)構(gòu)大大地抑制了植物的生長(zhǎng)，由于根不能伸展穿透土壤。Compactionnotalleviatedbyfreeze/thawcycles-RomanwheeltracksstillvisibleinEngland.結(jié)冰/解凍循環(huán)不會(huì)減輕緊密結(jié)構(gòu)—羅馬輪距在英格蘭依然可見(jiàn)PedotransferFunctions(PTFs)(SaxtonandRawls,2004).土壤傳遞函數(shù)(PRFs)（薩克斯頓和羅爾斯，2004）。CompactionandOMgreatlyaffecttheunderlyingtexturalclasspropertiesofthemineralsoils.緊密結(jié)構(gòu)和有機(jī)物質(zhì)極大地影響無(wú)機(jī)土壤的基本結(jié)構(gòu)類型特點(diǎn)PTFequationspredictsaturatedhydraulicconductivity(Ksat),suctionwettinghead(Ψ),fieldcapacity,andwiltingpoint.土壤傳遞函數(shù)(PTF)等式預(yù)測(cè)飽和水力傳導(dǎo)率，吸入水頭，土壤毛細(xì)含水量，和萎蔫點(diǎn)。TheSPAWmodelatSaxton’swebsiterecommendedtobeusedtoobtainKsat.推薦使用在薩克斯頓網(wǎng)站上的SPAW模型來(lái)獲得Ksat值。SPAWprovidesconservativeresultswithouthavingtouseasafetyfactor(typically2).SPAW模型能在非必須使用安全因子的情況下提供保守的結(jié)果(類型2)SoilProperties-SPAWModelGuidance

土壤特點(diǎn)—SPAW模型指導(dǎo)SPAWusedtoestimatesaturatedandunsaturatedhydraulicconductivitiesasfunctionofsoilpropertiesandmoisture.Veryusefulformodelparameters.SPAW曾用來(lái)預(yù)估飽和與不飽和水力傳導(dǎo)率，將其作為土壤特點(diǎn)和濕度的函數(shù)。這些是非常有用的模型參數(shù)。InfiltrationComputations

下滲計(jì)算IntheGreen-Ampt(G-A)formulation,infiltrationrateiscomputedasfollows:在格林安姆特方程式中，下滲速率的計(jì)算如下：whereF(t)isvolumeinfiltratedt,Ksat

issaturatedhydraulicconductivity,h0isthepondingdepth,Ψisthecapillarysuctionheadatthewettingfront,andΔθisinitialmoisturedeficit.其中F(t)是下滲體積t,

Ksat是飽和水力傳導(dǎo)率，h0是積水深度，Ψ是在濕潤(rùn)界面的毛細(xì)吸入水頭，Δθ是初始濕度差。G-AaccurateforeachlocationforKsat

andΨ,butperviousareashaveverywiderangeofvalues.格林安姆特對(duì)于每一個(gè)地點(diǎn)的Ksat和Ψ都是準(zhǔn)確的，但透水區(qū)域的值范圍非常廣。SorunoffflowsfromareaswithlowKsat

andΨtoareaswithhigherKsatandΨ所以各區(qū)域的徑流會(huì)從Ksat和Ψ的低值區(qū)流向Ksat和Ψ的高值區(qū)。Asaresult,infiltrationratesactuallyincreaseasrainfallintensityincreases.結(jié)果是，由于降水強(qiáng)度的提高，下滲速率實(shí)際上提高了。ThisiswhattheCurveNumber(CN)methodsimuatesasanexponentialdistributionofinfiltrationparametersoverspacesubjectedtoanexponentialdistributionofrainfallovertime(Yu,1998).這是曲線數(shù)(CN)法模擬下滲參數(shù)在空間上的一個(gè)指數(shù)分布的結(jié)果。這個(gè)分布受制于降雨在時(shí)間上的指數(shù)分布。(Yu,1998)MostcommonmethodinUSAusedfordesigningfloodcontrolfacilities.在美國(guó)用來(lái)設(shè)計(jì)洪水控制的最普遍方式是控制市政管線。CurveNumberHydrology

曲線數(shù)水文Baseduponobservationsofthousandsofeventsinmostlyruralwatersheds,VictorMockusgeneratedthefollowingequation:基于對(duì)數(shù)以千計(jì)大多數(shù)發(fā)生在鄉(xiāng)間流域事件的觀測(cè)，維克多莫卡斯發(fā)明了以下等式：WhereQisrunoffin24hourevent,Pisprecipitationdepth,Sisstoragedepth(theamountthatinfiltratesover24hours)andInitialabstractionIa(theamountthatdoesn’trunoff)is20%ofS.其中Q是24小時(shí)事件徑流，P是降雨量，S是貯水量（超出24小時(shí)的下滲量）和初損量Ia（沒(méi)有流走的量）是S的20%。NotethatIa(initialabstraction)isalargeproportionofsmallevents.Shouldbelower.注意Ia（初損量）占小事件很大的一部分。應(yīng)該稍微降低。ThefollowingequationrelatesStoCurveNumber(CN):通過(guò)以下等式將S與曲線數(shù)(CN)聯(lián)系起來(lái)：ThehighertheCN,thelowerS,andIawillbe.CN越大，S越小，Ia也越小。CurveNumber

Hydrology

曲線數(shù)水文(Pitt,1987)DuetoIabeingtoobiginsmallevents,“effective”CNinsmalleventshastoincrease.由于Ia在小事件中比例太大，必須增大小事件中的“有效”的曲線數(shù)。CurrentthinkingisthatIashouldbecloserto5%ofS,not20%.現(xiàn)行的想法是Ia應(yīng)該更接近S的5%，而不是20%。IaisreallythesuctiontermintheGreen-Amptequation,notdepressionstorage.Ia是格林安姆特等式中真正的吸入量，而不是洼地貯水量。LIDHydrology

LID水文(Lucas,2004)（盧卡斯，2004）Pitt(1987)developedresponsefordisturbedurbansoilsconfirmedbyobservations.皮特（1987）為受擾城市土壤開(kāi)發(fā)出了受觀測(cè)限制的曲線。PittequationsusedinDURMMmodelforDelawareinUSA(Lucas,2004).皮特等式在美國(guó)DURMM模型中被用于特拉華州。ThisalloweduseofextensiveNRCSCNdatasetforsmallstormresponses.這使得大規(guī)模地運(yùn)用國(guó)家自然保護(hù)服務(wù)的CN數(shù)據(jù)集作用于小型暴雨曲線得到了允許。LIDHydrology

LID水文Remember,itisrunoffcapturedthatiswhatreallymatters,notprecipitationfalling.記住，起到作用的是徑流收集而不是降水下落。Percentageofrunoffisfunctionofmixbetweenimperviousandpervious,andperviousCN.徑流的百分比是不透水率和透水率混合與透水CN之間的函數(shù)。Tableshows50%perviousatCNof61,liketowerprojectwithlandscaping.表格顯示了在61CN處有50%透水率，比如景觀美化的塔工程。Ifallrainfallupto30mm(1.18inch)intercepted,representscapturing80%ofannualrunoff.如果截留的降雨達(dá)到30毫米(1.18英寸)，代表收集了80%的徑流。Ifallrainfallupto51mm(2.00inch)intercepted,representscapturing93%ofannualrunoff.如果截留的降雨達(dá)到51毫米(2.00英寸)，代表收集了93%的徑流。Asimperviousincreases,capturepercentagegoesdown.隨著不透水率的增加，收集的百分比降低。INFILTRATION下滲:Positivelyaffectedbyhighorganicmatter,lowcompaction,andpresenceofplants.正比于高含量的有機(jī)物質(zhì)，低緊密性，和植物存在度。Methodstoimprovethesefactorscanhaveverylargeeffectoninfiltrationrates.提高這些因素的方法可以極大地作用于下滲速率。HYDROLOGY水文:RunofffromdisturbedpervioussoilsoftenmuchhigherthanCNmethod

predicts.來(lái)自受擾透水土壤的徑流常常比CN法預(yù)測(cè)的更多。Runofffromsmalleventsdominatedbyimperviouscover.來(lái)自小事件的徑流主要由不透水覆蓋面控制。TypicalapplicationofcompositeCNmethodnotappropriateforLIDhydrology.綜合CN法的典型應(yīng)用并不適合LID水文。Mustsegregateconnectedimperviousfromdisconnectedimpervious.必須把連接的不透水區(qū)和分散的不透水區(qū)分離開(kāi)。Mustusedesignstorm(DS)thatismorerepresentativethanfloodstorm.必須使用暴雨設(shè)計(jì)(DS)，比暴雨洪水更有代表性。LIDHydrologyLID水文LIDModeling

LID模型Allapproachesintendpre-developmenthydrologytobereplicatedbytheprovisionofBMPs.所有想要通過(guò)BMPs的提供復(fù)制開(kāi)放前水文的方式。RationalMethodisuseless,sincedoesnotrouteorattenuatebydetentionorinfiltration.推算方式是沒(méi)有作用的，因?yàn)樗荒苎菟?，也不能被滯留或者下滲衰減。Specificdischargerateoversimplifies,sincesameeventhoughsoilsandvegetationverydifferent.特定排放速率過(guò)度簡(jiǎn)化，因?yàn)榧词故峭瑯拥耐寥篮椭脖?，下滲速率還是很不一樣的。Specificdetentionvolumeisalsoinadequateforsamereasons.Butusefulforinitialscreening.同樣的理由，特定的滯留量也是不夠的。但對(duì)于初步篩選還是有用的。MustuseroutingapproachsoBMPsdeterminedbyinitialscreeningmeetdischargecriteria.必須使用演算的方法，因此經(jīng)由初步篩選決定的BMPs可以達(dá)到排放標(biāo)準(zhǔn)。TheCNapproachisusednationallythroughoutUSAforbothforscreeningandforrouting.CN法在整個(gè)美國(guó)范圍內(nèi)被用于篩選和演算。ItisthebasisformanymodelssuchasTR-20,HEC-1.WediscussTR-20(simplifiedasTR-55).它也是很多模型如TR—20，HEC—1的基礎(chǔ)。我們討論一下TR—20（簡(jiǎn)化成TR—55）。LIDModeling

LID模型Forinitialscreening,canusetheoverallcompositeCNapproach.對(duì)于初期篩選，可以使用總體綜合CN法。Volumerequiredisdifferenceinrunoffdepthsfrompre-developmenttopost-development.要求的體積在不同徑流量中從開(kāi)發(fā)前到開(kāi)發(fā)后都是不同的。Multipliedbyarea,thisgivestotalvolumerequired.乘上面積，這可以算出要求的總體積。BMPsthencomputedaccordingtovolumeprovidedinsurfacestorageandinmedia/stonevoids.BMPs之后可以依據(jù)在地表貯存提供的體積和媒介/石頭間的縫隙計(jì)算。Fordetaileddesign,segregatevarioustypesofsourceareastodeterminecontributionofeach.對(duì)于詳細(xì)的設(shè)計(jì)，分離不同類型的源頭區(qū)域來(lái)決定每一樣對(duì)設(shè)計(jì)的貢獻(xiàn)。Segregatedirectlyconnectedeffectiveimperviousarea(EIA),sincegeneratesrunoffeveryevent.分離直接連接的有效不透水區(qū)域(EIA)，因?yàn)槊恳豁?xiàng)都會(huì)產(chǎn)生徑流。Compositedisconnectedimperviousareas(DIA)andadjacentpervioustogeneratetheirrunoff.綜合分離的不透水區(qū)域(DIA)和鄰近的透水面來(lái)生成他們的徑流。Naturalperviousareaswillgenerateverylittlerunoffatall.天然透水區(qū)域會(huì)幾乎不產(chǎn)生徑流。Multiplysourceareasbytheirdepthstogetloads.將源頭面積乘上他們的深度可以得到載量。LIDModeling

LID模型NATURALPERVIOUSAREAS天然透水區(qū)域GRADEDPERVIOUSAREAS分級(jí)透水區(qū)域DISCONNECTEDIMPERVIOUSAREAS分離的不透水區(qū)域CONNECTEDIMPERVIOUSAREAS連接的的不透水區(qū)域FLOWPATHANDMASSLOADCOMPUTATIONS水流路徑質(zhì)量承載計(jì)算TOBMP(s)轉(zhuǎn)成BMP(s)DesignStorm(DS)Summary暴雨設(shè)計(jì)(DS)方式??Designstorms(DS)areverycommonwaytodesignhydraulicstructures.暴雨設(shè)計(jì)(DS)是非常普遍的設(shè)計(jì)水力結(jié)構(gòu)的方式。Averagerecurrenceinterval(ARI,orfrequency)depthsarebasedonlongtermrainfallrecords.平均重復(fù)周期(ARI,或頻率)深度是基于長(zhǎng)期降雨記錄的。DSsynthetichyetographsoftenaccentuatepeakflowssincedirectedtowardflooding.暴雨設(shè)計(jì)(DS)合成雨量圖常常會(huì)削弱水流峰值因?yàn)閷⑵渲苯訉?dǎo)向洪水。Sodesignstormsmaynotrepresentanyactualevents,butusefulforinitialdesign.所以暴雨設(shè)計(jì)一般不會(huì)代表任何真實(shí)事件，但對(duì)初期設(shè)計(jì)很有用。DSmodelscanrapidlyauditcapacityandperformance,andoptimizedesign.暴雨設(shè)計(jì)(DS)模型可以快速的審查設(shè)計(jì)的能力和性能并優(yōu)化設(shè)計(jì)。TR-20ismostusedmodelinUSA,basedonCNmethods.HereusedwithHydroCAD.TR-20是在美國(guó)最常用的基于CN方法的模型。這里講其與HydroCAD一起使用。WhileDSmodelsareveryuseful,moreinformationisneededtoevaluateSCMs.當(dāng)暴雨設(shè)計(jì)(DS)模型非常有用時(shí)，需要更多信息來(lái)評(píng)估雨水管理措施。ContinuousSimulationvs.DesignStorm

連續(xù)性模擬vs.暴雨設(shè)計(jì)Designstorms(DS)donotrepresentanyactualevents,sousefulonlyforinitialdesign.暴雨設(shè)計(jì)(DS)并不代表任何真實(shí)事件，所以只適用于初期設(shè)計(jì)。Continuoussimulation(CS)simulatesresponseusinglongtermrainfallandflowrecords.連續(xù)性模擬(CS)可將長(zhǎng)期降雨和水流記錄用于模擬結(jié)果。FlowDurationCurve(FDC)ismuchbetterindicatorofperformancethanaDSanalysis流量歷時(shí)曲線(FDC)是比暴雨設(shè)計(jì)(DS)分析更好的性能指標(biāo)TheFDCcomparesthedurationofflowsofdifferingmagnitudes,soalleventsrepresented.把流量歷時(shí)曲線與不同量級(jí)水流的持續(xù)時(shí)間作比較，因此可以代表所有事件。TheFDCisthefundamentalmetricofhowwellLIDSCMswork.流量歷時(shí)曲線是LID雨水控制措施有效程度的基本度量。CSdatacanalsodefineDSdepth.Ifenoughdataavailable,DShyetographalsoderived.連續(xù)性模擬可以定義暴雨設(shè)計(jì)深度。如果有足夠的可用數(shù)據(jù)，暴雨設(shè)計(jì)雨量圖也可以推導(dǎo)得出。CSModels-SWMMEPASWMMisverycomprehensiveCSmodel.SWMMnowincludesusefulmodulesforLIDBMPssotheycanbemodeledquitewell.SWMMalsoincludesaquifers,whichcanmimicoverlandflowhydrologyquitewellDetailsofSWMMoperationandexamplesarefocusoftheafternoonsession.First,mustaddresshowbothDSandCSmodelsshouldaddressverticalandlateralflowinlayeredsystems.ThiselementiscriticalinmodelingLIDBMPs,andoftenoverlooked.Followingsectionpresentshowflowsinlayeredsystemssuchasbioretentionaremodeled.FlowDurationCurvecomparisonbetweenUrbanandForestStreams.城市和森林河流的流量歷時(shí)曲線比較Urbanizationgreatlyincreasesbothdischargeanddurationoferosiveflowsoverbankfull.城市化極大地增加了超出滿槽流的水流排放和侵蝕流的維持。Duetologarithmicscale,thesedifferencesareevengreateractualmagnitude.由于是在對(duì)數(shù)尺度下，這些差別會(huì)變得比實(shí)際量級(jí)更大。UrbanStream城市溪流ForestStream森林溪流DischargeIncreases~10x排放提高~10倍FlowDurationIncreases~10x水流持續(xù)時(shí)間~10倍“Normal”FlowRate“正?！绷魉貰ankfullFlowRate滿槽流速BaseFlowDecreases基礎(chǔ)流量減少ContinuousSimulation連續(xù)性模擬流量歷時(shí)曲線WhyFDCs?-PhysicalandChemical

為什么用流量歷時(shí)曲線(FDCs)？—物理的和化學(xué)的(原因)ImperviousFDCimplicationsforFlooding:Allrunoffeventshavemuchhigherflowscomparedtonatural.Somanymorebankfullflowevents(from<1:yrto>10/yr).Such“flashy”streamsresultinfrequentnuisanceflooding.ImperviousFDCimplicationsforBankStability:Resultanthigherbankfullflowvastlyincreaseserosiveenergy.Sobankerosion,downcuttingandchannelincisionaccelerated.Resultingerosionmajorsourceofsedimentsinstreams.ImperviousFDCimplicationsforBaseFlow:Decreasedbaseflowduetodiversiontorunoff.Baseflowtemperatureshigher,anddissolvedoxygenlower.不透水流量歷時(shí)曲線(FDC)對(duì)洪澇的含義

:所有徑流事件都有比天然徑流高得多的流量所以有更多的漫灌流事件（從少于1次每年到多余10次每年）。比如“瞬間的”潮流導(dǎo)致頻繁的洪澇災(zāi)害。不透水流量歷時(shí)曲線(FDC)對(duì)河岸穩(wěn)定性的含義:因此產(chǎn)生的更多的漫灌流極大地提高了侵蝕能量。所以河岸侵蝕，向下侵蝕和河道切削加速。導(dǎo)致侵蝕河流中沉積物的主要源頭。不透水流量歷時(shí)曲線(FDC)對(duì)基流的含義:由于徑流分散從而減低基流.基流溫度更高，溶解的氧氣更少。WhyFDCs?-Biological

為什么用流量歷時(shí)曲線(FDCs)？生物的（原因）ImperviousFDCeffectsuponBenthicMacroinvertebrates:Increasedflowdisruptsbreedingcyclesandfeeding.Increasedfloweliminatesmanyindividuals.Sedimentssmotherbreedingandrefugesites.Floodswashawaywoodydebrishabitat.Lossofhabitateliminatesmanyspecies.ImperviousFDCeffectsuponFish:Mostmacroinvertebratefoodsourceseliminated.Increasedflowdisruptsbreedingcyclesandfeeding.Sedimentssmotherbreedingandrefugesites.Floodswashawaywoodydebrishabitat.Lowflowconditionselevatetemperatureandreduceoxygen.Lossofhabitateliminatesmanyspecies.不透水流量歷時(shí)曲線(FDC)對(duì)海底大型無(wú)脊椎動(dòng)物的影響:提高的水流擾亂繁殖周期和覓食。提高的水流消除許多的個(gè)體。沉積物抑制繁殖和避難場(chǎng)所。洪水沖刷掉棲息地的木質(zhì)碎屑。

棲息地的失去會(huì)消除許多物種。不透水流量歷時(shí)曲線(FDC)對(duì)魚類的影響:大多數(shù)無(wú)脊椎動(dòng)物的食物源被消除。提高的流量擾亂繁殖周期和覓食。沉積物抑制繁殖和避難場(chǎng)所。洪水沖刷掉棲息地的木質(zhì)碎屑。

低流量條件下提高溫度和降低氧含量。棲息地的丟失會(huì)消除許多物種。BioretentionPlanterModeling

生態(tài)滯留種植模型PhiladelphiaWaterDepartment(PWD)investigateddistributedLIDsystemstoreducethevolumeofrunofffromcombinedseweroverflows(CSOs).Alternativeisa$4Btunnel.費(fèi)城水部門(PWD)調(diào)查了受擾LID系統(tǒng)減少來(lái)自結(jié)合區(qū)污水溢流(CSOs)的徑流量。選擇的是一個(gè)4百萬(wàn)美元的隧道。Infiltratingbioretentionsystemscombineextendeddetentionandinfiltrationprocesses.下滲生態(tài)滯留系統(tǒng)結(jié)合了的延伸的滯留和下滲過(guò)程。Thisfollowingpresentshowyoucandesignthesesystemstomeettheseobjectives.接下來(lái)這呈現(xiàn)了如何設(shè)計(jì)這些系統(tǒng)來(lái)達(dá)到這些目標(biāo)。Thenpresentshowyoucanmodelthesedesignstoconfirmhowwellobjectivesaremet.然后呈現(xiàn)了如何模擬這些設(shè)計(jì)來(lái)確認(rèn)目標(biāo)的完成程度。Constantvs.dynamicflowDesignStorm(DS)routingmethodsexamined.連續(xù)流vs.動(dòng)力流暴雨設(shè)計(jì)(DS)演算方式的檢查。Dynamiccontinuoussimulation(CS)methodusedtoobtainannualperformanceresults.動(dòng)力的連續(xù)性模擬(CS)法曾用來(lái)獲得每年的表現(xiàn)結(jié)果。Allmethodsusemultiplestoragenoderoutingapproach.所有的方式使用了多重存儲(chǔ)節(jié)點(diǎn)演算方式。BioretentionPlanterModeling

生態(tài)滯留種植模型ModelinglayeredLIDSCMsisnottrivial,especiallyinbioretentioncells.Thisshowstypicalfreedischargesystem.模型中分層的LID雨水控制措施并非是不重要的，尤其在生態(tài)滯留池中。這表現(xiàn)了典型的自由排放系統(tǒng)。However,underdrainflowsinrapidmediausedoftenexceedtargetdischargecriteria.無(wú)論如何，盲管快速地流進(jìn)使用的媒介常常會(huì)超出目標(biāo)排放標(biāo)準(zhǔn)。ThesecriteriacanbequitelowforbothCSOsandforstreamchannelprotection.這些標(biāo)準(zhǔn)可以變得很低，對(duì)于結(jié)合區(qū)的污水溢流和對(duì)于河流河道保護(hù)的時(shí)候。

Soanoutletisusuallyputontheunderdraintocontrolflows.所以一個(gè)出水口經(jīng)常會(huì)加上盲管一起控制水流。OutlettoDischarge排水口排放FlowthroughMedia水流經(jīng)媒介FlowthroughUnderdrain水流過(guò)盲管FlowsthroughOpenOutlet水流過(guò)打開(kāi)的出水口SurfacePonding表面積水FlowintoSoil水流進(jìn)土壤Inflowfromstreet來(lái)自街道的流入量Media媒介Stone碎石Outlet出水口InletDrain排水Plants植物Thedummycolumnsallowverticalflowstoberoutedasifgoinghorizontally.虛擬柱使垂直流動(dòng)可被當(dāng)做水平流進(jìn)行演算。Surfacepondingheadcarriedintothemediatoestablishhydraulicgradeintomedia.地表積水水頭被運(yùn)送至媒介來(lái)建立進(jìn)入媒介的水力等級(jí)。FlowthroughthemediaisfunctionofDarcy’sLaw.Setbydifferencebetweenhydraulicgradeinpondandhydraulicgradeintostone.流經(jīng)媒介的水流達(dá)西定律的函數(shù)。由積水的水力等級(jí)和進(jìn)入碎石的水力等級(jí)之間的差異設(shè)定。Lateralflowlossesalsoinstoneifsystemsarewide,stoneissmall,andthelayeristhin.橫向流損耗在碎石內(nèi)也會(huì)發(fā)生，如果系統(tǒng)寬，而石頭小，且該層比較薄的話。Theselossesmustbeaccountedforwhenprojectingoutflowsfromunderdrains.這些損耗必須被考慮進(jìn)去當(dāng)規(guī)劃盲管流出量時(shí)。SurfacePond地表積水Stone碎石Flowcontrolledbyorificearraytomimicrapidinitialinflow,thencarryhydraulicgradientwithlowlosses.被孔口控制的水流排列模仿迅速的初始流入，然后低損耗得運(yùn)送水力梯度。FlowdeterminedbyDarcy’sLawasfunctionofhydraulicgradient.由達(dá)西定律決定的水流是水力梯度的函數(shù)。Dischargecontrolledbymediaflowand/oroutletcapacity.被媒介流量和/或出水口容量控制的排放。HydraulicgradeintoMedia進(jìn)去媒介的水力等級(jí)HydraulicgradeintoStone進(jìn)入碎石得水力等級(jí)Media媒介DummyColumnallowsforverticalflowstoberoutedasifhorizontal虛擬柱使垂直流動(dòng)可被當(dāng)做水平流進(jìn)行演算。HydraulicgradeintoOutlet進(jìn)入排水口水力等級(jí)BioretentionPlanterModeling

生態(tài)滯留種植模型BioretentionPlanterPlan

生態(tài)滯留種植平面圖Planter/Trenchsetintothesidewalk,astwo-partsystem.種植/溝渠設(shè)立進(jìn)人行道，作為兩部分的系統(tǒng)。Planterisa90cmwideby5.1mlandscapedislandbycurb.種植區(qū)是一個(gè)90厘米寬5.1米路緣包圍的景觀島。Trenchunderthesidewalkis150cmwide,linksplanters.人行道下的溝渠150厘米寬，連接著種植區(qū)。Inthismodel,trenchis5’deep.在這個(gè)模式里，溝有5英尺深。Inflowscapturedbycurbcutandspreadoversurface.流入量通過(guò)路緣坡收集和在表面?zhèn)鞑ラ_(kāi)去。Flowsfirstentermediaandthendrainintostonetrench.水流首先進(jìn)入媒介，然后排放進(jìn)入石渠。Intentistogetasmuchinfiltrationvolumeaspossiblewithoututilityconflicts.目的是在不和市政管線沖突的情況下，盡可能多的得到下滲量。(GraphiccourtesyofCDMandPWD)BioretentionPlanterSections

生態(tài)滯留種植歐剖面圖Peakinflowsdirectlyintotrenchviadomeinlet.高峰流入通過(guò)圓頂入口直接導(dǎo)向溝渠。Drainraised50cmdirectsflowintomediainsmallevents.在小事件中，排水升高50厘米直接流進(jìn)媒介。Trenchunderdrainconveysflowtooutletstructure.盲管溝把水流運(yùn)送至排水口結(jié)構(gòu)。Trenchinthisexampleis150cmdeepsomoreintercepted.這個(gè)樣例中的溝渠有150厘米深，所以更多的截留。OutletstructurecomprisesnarroworificedesignedtomeetCSOcriteria,plusoverflowweirforhighflows.排水口結(jié)構(gòu)由設(shè)計(jì)符合CSO（結(jié)合區(qū)污水溢流）標(biāo)準(zhǔn)的窄孔口和針對(duì)高流量的溢流孔組成。(CDM,2008)BioretentionDSRouting

生態(tài)滯留暴雨設(shè)計(jì)演算DSmodelsetup,withseparatenodesforthecurbcutinlets,planterponds,plantermediaandtrench.暴雨設(shè)計(jì)模型的設(shè)置有分離節(jié)點(diǎn)的路緣坡入口，種植池，種植媒介和溝渠。Surroundingsoilnodemimics“suctionhead”whereinitialratesintodrysoilsarefaster.周圍的土壤節(jié)點(diǎn)模擬“吸入水頭”，進(jìn)入干燥土壤的初始速率會(huì)更快。PlanterPondsdischargeintomediaandtrench.種植池排放進(jìn)入媒介和溝渠。ConstantflowDS(Φindex)at4in-h-1routingcomparedtodynamicflowintothemedia.恒定的水流暴雨設(shè)計(jì)（Φ

指數(shù)）在4/英寸演算與動(dòng)力流進(jìn)入媒介做比較。Flowsfromthemedia1)basedonratingcurverespondingtosaturationstatus.來(lái)自媒介的水流1)基于對(duì)于飽和狀態(tài)的評(píng)定曲線。InfiltratedflowsfromtrenchroutedaccordingtosoilKsat,appliedtowettedarea.來(lái)自溝渠的下滲水流路徑依據(jù)土壤的Ksat值，適用于潮濕區(qū)域。Surroundingsoilnodemodeledasnarrowcolumnfilledbyasmallorificefromtrench.周圍的土壤節(jié)點(diǎn)模擬成窄小的布滿來(lái)自溝渠小孔的圓柱。Thisnodehasaconstantoutflowtoemptybetweenevents,representingsoilrecovery.這個(gè)節(jié)點(diǎn)有穩(wěn)定的流出量流向項(xiàng)之間的空曠地帶，代表著土壤恢復(fù)。(Lucas,2009)BioretentionRouting

生態(tài)滯留演算PreprocessinginExceldevelopstablesforstage/area/perimeterandmediaratingcurve.在Excel內(nèi)預(yù)處理，生成水位/區(qū)域/邊緣和媒介的評(píng)定曲線。Alsodevelops“equivalentorifice’sizeforthemediainflowandsurroundingsoilresponse.也生成一個(gè)“相當(dāng)于孔口”尺寸給媒介流入量和周圍的土壤結(jié)果。Notesoilinfiltrationrateisonly2.5mm-h-1.Usedtoprojectstage/outflowratesforKsat.注意土壤下滲速率只有2.5毫米每小時(shí)。使用給Ksat的項(xiàng)目水位/流出速率。ThisutilizesfullpotentialofDSorCSmodelssuchasHydroCADorSWMM5,whichaccountforbackwaterusingratingcurves(ver.5.013).這個(gè)利用了暴雨設(shè)計(jì)或連續(xù)性模擬模型（如HydroCAD或SWMM5）全部的潛能。這把使用評(píng)定曲線的回水考慮了進(jìn)去。(Lucas,2009)BioretentionCSRouting

生態(tài)滯留連續(xù)性模擬演算SWMM5.013usedforCSresponse.SWMM

5.013版本用于連續(xù)性模擬的反應(yīng)。UsingsameinputparametersasDSmodel,SWMM5runwithsameDSeventtoobtainsimilarresponse.使用同樣的輸入?yún)?shù)作用于暴雨設(shè)計(jì)模型，SWMM5運(yùn)行同樣的暴雨設(shè)計(jì)事件來(lái)獲得類似的結(jié)果。OncemodelequivalencyconfirmedforDSeventcomparison,SWMM5thenrunwith“DesignYear”rainfall.一旦模型的對(duì)于暴雨設(shè)計(jì)事件比較的等價(jià)性確認(rèn)了，之后SWMM5可以對(duì)“設(shè)計(jì)年”降雨進(jìn)行運(yùn)行。(Lucas,2009)“DesignYear”basedon2005rainfalldistribution,whichincludedeventsrepresentativeofannualdistributionofeventsobservedover50years.“設(shè)計(jì)年”基于2005降水分布，包含了能代表超過(guò)50年的每年觀測(cè)事件的分布的項(xiàng)。BioretentionCS-DSRouting

生態(tài)滯留連續(xù)性IdenticalHydrographsandStorageDepths,38mmInch(~0.6YearARI)“SampleD”DSEvent.同樣的水位圖和貯水量，38毫米英寸(0.6年平均重復(fù)周期)“樣本D”暴雨設(shè)計(jì)事件。Outflowsinconstantheadmediamuchlowercomparedtohead-dependentrouting.水頭媒介流出量持續(xù)比基于水頭的演算要低得多。(Lucas,2009)BioretentionCSRouting

生態(tài)滯留連續(xù)性模擬演算HydrographsandStorageDepths,January12-14,2005Event.水位圖貯水量，1月12-14日，2005事件。Characteristic“doublehump”afterpeakofinflowhydrograph,duetopondingdepth.“雙峰”特點(diǎn)出現(xiàn)在流入峰值水位圖之后，這是由于積水的深度。3.50lps/ha.(0.05cfs/ac.)CSOthreshold(Lucas,2009)BioretentionCSRouting

生態(tài)滯留連續(xù)性模擬演算3.50lps/ha.(0.05cfs/ac.)CSOthresholdHydrographsandStorageDepths,98.3mm(3.87in.)eventofOctober8,2005.水位圖和貯水量，98.3毫米（3.87英寸）2005年10月8日事件。Notehowmediaoutfloweliminatedduringpeakinflow-actuallynegativeduetotrenchfull.留意如何在流入峰值期間消除媒介流出量—實(shí)際上是負(fù)相關(guān)由于溝渠已滿。Eveninthislargeevent,seesubstantialvolumeandpeakflowreductions.大型事件中的事件，可以看出大量的體積和水