一种新型的微润灌溉系统水力特性及试验研究

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1、万方数据太原理工大学硕士研究生学位论文curvilinearequation：a=93．00Hof81．Thedeviationfactorscausedbymoistubeareallwithin9％，andexperiment’Smaterialsreachagoodgrade．Theflowoflmand2mhydraulicheadscorrelatessignificantwithwatertemperatureinO．O1level，andthetwocasesshowpositivecorrelation．Whenwatertemperaturerises，the

2、flowincreases，andwhenwatertemperaturereduces，theflowdecreases．Therelationshipbetweenmoistube’Sflowandwatertemperatureislinear．Whentemperaturechanges1℃，thevariationofflow：lmwaterpressurecorresponds5．89ml，and2mwaterpressurecorresponds9．26ml，whichindicatesthatthegreaterhydraulichead，thelargerim

3、pactthetemperatureonflow．Therelationshipbetweenmoistube’Spressureandflowisexponentialrelationship，andflowindexisbiggerthan0．5．Differenttimeofobservation’Swettingfrontshapeissimilartoacircleusedbymicro—irrigationzoneasthecenter,andthewettingfrontthatlayalongthedirectionofmoistubeisbasicallypa

4、ralleltomoistube．Withtheprolongedtimeofirrigationandtheincreaseofinfiltrationcapacity,differentdirections’wettingfrontshapesinwettingbodyareever-expanding，butthespeedofextensionisslowdowngradually．Afteracertaintimeofwatering，thespeedofwettingfront’Sextensionslowsdownobviously,andfinally,ital

5、mostdoesn’texpandanymore．Atthesametimeofirrigation，wettingbody’Swettingradiusinbothverticallyupandverticallydownisalmostequaltowettingradiusinhorizontaldirection．ThevaryingtendencyamongWettingfrontX、andcumulativeinfiltrationexpressedbyIV万方数据太原理工大学硕士研究生学位论文powerfunction，whichhasahighcorrelati

6、onindexaboveO．90．Inthefieldexperiment，theinfiltrationcapacitymoistubeis233．9ml／h／min5meffectivehead．Asirrigationcontinues，flowpresentsagraduallydecreasesituationbecauseofthechemicalblockageinmoistube．Aboutonemonth，thedecreaseofflowreachastablenumericalvalue，andtheflowofmoistubeis169．3ml／h／m．

7、Theflowofmoistube’Sdecayrateis27．6％，anditwillnotdecaylater．SoilmoisturecontentiSalmostafixedamountthatiS60％ofsoilWaterrate．Inthecaseofnotseriousblockingofmicro-irrigation，thevolumeofirrigationwaterCanbasicallymeetthecoRongrowingrequirement．Compared