本文關(guān)鍵詞：水利工程對(duì)向海濕地水文與生態(tài)的影響，由筆耕文化傳播整理發(fā)布。

3??結(jié)論與建議

在干旱、半干旱地區(qū),只有在降雨分布很集中的豐水年,才可能出現(xiàn)一些適合濕地植物生長(zhǎng)的濕潤(rùn)期,而在其他絕大多數(shù)時(shí)間,地下水埋深很大,不具備濕地特征。外界入水量進(jìn)入的時(shí)機(jī)不同,對(duì)濕潤(rùn)程度的提高也不同,影響因素有蒸發(fā)、前期及后期降雨量等。一般來(lái)說(shuō),在生長(zhǎng)期初期和末期,由于蒸發(fā)量相對(duì)較小,同樣的水量對(duì)濕潤(rùn)程度的提高相對(duì)較大。在力求滿(mǎn)足美國(guó)陸軍工程師團(tuán)的最小水文準(zhǔn)則時(shí),該地區(qū)的臨界供水量為12~15cm。對(duì)于干旱地區(qū),不同時(shí)期的相同來(lái)水量,會(huì)引起不同的濕潤(rùn)變化,這對(duì)于濕地保護(hù)和恢復(fù)都是應(yīng)該注意的問(wèn)題。臨界水量是該地區(qū)可以維持濕地水文的最小水量,因此在水資源規(guī)劃時(shí),應(yīng)該給予足夠的認(rèn)識(shí)。

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Studyonhydrologicaldynamicsandformationcriteriaofwetlands

JIAZhong??hua,LUOWan,ZHOUXiao??xia,LIUXiao??ning

(Xi??anUniversityofTechnology,Xi??an??710048,China)

Abstract:ThedataofprecipitationandsoilpropertiesinXi??anareaareanalyzedbyusingthehydrologi??calmodelDRAINMODtoinvestigatetheinfluenceofincomingwateronvariationofgroundwatertable.ThemodelissuggestedbytheWetlandResearchInstitute,DepartmentofAgriculture,USA.Atthesametime,theidentificationcriterioncurrentlyadoptedinUSisappliedtoanalyzethenecessarycriticalincom??ingwaterforwetlandformation.Itisfoundthattheincomingwaterwiththesameflowdischargemayre??sultindifferentwetnessindifferentmonthsinayear.Consequently,thenecessarywaterflowforformingthecriticalhydrologicalconditionisnotaconstant.

Keywords:wetland;wetlandhydrology;DRAINMOD;modeling

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FractureanalysisoninducedjointofRCCdams

SONGYu??pu,ZHANGLin??jin,YINFu??xin

(DalianUniversityofTechnology,Dalian??116024,China)

Abstract:Inordertodeducetheformulaforstressintensityfactoroftwo??directionintervaljointinRCCdams,thestressintensityfactorofthecracktipsinellipticalandrectangularinducedjointsareanalyzedbyusing3??DFEM.Thecomparisonshowsthatthecalculationresultsofthesetwokindsofjointareap??proximatelythesame.Buttheellipticalmodelismoreconvenientforpracticaluse.Consequently,theformulaofthestressintensityfactorforthecracktipsofellipticalinducedjointinfinitebodyisextendedtomeetthecalculationforfinitebody.Onthisbasis,theregressionanalysismethodisadoptedtoestab??lishtheformulaforcalculatingthestressintensityfactoroftwo??directionintervaljoint.Intheformulathesizeanddimensionsofinducingplateaswellastheinfluenceofweakeningdegreearetakenintoaccount.Keywords:RCCdam;inducedjoint;stressintensityfactor;3??DFEM

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  本文關(guān)鍵詞：水利工程對(duì)向海濕地水文與生態(tài)的影響，由筆耕文化傳播整理發(fā)布。