给排水专业英语Unit4电子教案.ppt

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1、SpecializedEnglishforWaterandWastewaterEngineering给排水专业英语主讲教师：李康Lesson4StormwaterCollectionandSewerDesign雨水收集和管道设计4.1WordsandexpressionsReviewDomesticwastewater生活污水Drainagesystem排水系统Combinedsewers合流制Separatesewers分流制Untreatedwater未处理水Finishedwater出水Organicpollutant有机污染物Bioche

2、micaloxygendemand(BOD)生化需氧量4.2NewwordsandexpressionsHydraulicload水力负荷Organicload有机负荷headloss水头损失microorganisms微生物Hardness硬度totalsuspendedsolids(TSS)总悬浮固体sedimentationbasins沉淀池Anaerobic厌氧的Aerobic需氧的，好氧的chemicaloxygendemand(COD)生化需氧量4.2Newwordsandexpressionsself-purification自然净

3、化open-channel明渠hydrograph水位图，水位曲线intensity-duration-frequencycurves强度-持续时间-频率曲线retentionbasins贮水池moisture水分，湿度4.3Importantsentences(第三段)DesignobjectivesDesignobjectivesaregenerallyestablishedduringtheplanningprocess.Traditionally,suchobjectivesdealtonlywithrunoffquantityandsp

4、ecifiedthedesiredlevelsofprotectionagainstfloodingbyspecifyingreturnperiodsofdesignrainfallevents.Theminordrainage,whichincludesundergroundsewersandsmallopenchannelsandprovideslocalconvenienceandpreventionofwaterponding,istypicallydesignedforshortreturnperiods,from1to10years.

5、Themajordrainagesystemconveysfloodflowsthroughurbanareasandincludeslargesewers,thenaturaldrainagesystem,swales,streetsandotheroverlandroutes.Thissystemisgenerallydesignedforreturnperiodsfrom50to100years.明确，指定积水重现期4.3Importantsentences1.(第六段)Rainfalldataareusedinurbanrunoffcal

6、culationsinvariousforms,dependingonthedesignapproachandcomputationalprocedureused.Themostcommonformsincludeintensity-duration-frequencycurves,syntheticdesignstorms,historicaldesignstorms,andactualorsyntheticlong-termrainfallrecords.Althoughtheliteratureonrainfalldataforstorms

7、ewerdesignisratherextensivetheissuesofuncertaintiesinrainfallinputsandtheirimpactoncalculatedrunoffflowhavenotbeenfullyresolved.Uncertaintiesincludeerrorsinpointmeasurements,andimpactsoftemporalandspatialdistributionsonestimatesofcatchmentrainfall.Otheruncertaintiesareintrodu

8、cedintheanalysisofobserveddatabyusingvariousassumptionswhichmayormay