结冰对乌梁素海水体富营养化的影响

/.Lde(湖泊科学），2017,29(4):811-818DOIIO.18307/2017.0404©2017byJournalofLakeSciences结冰对乌梁素海水体富营养化的影响$张岩\李畅游2,高宁\史小红2,乔玲敏1(1:烟台大学土木工程学院，烟台264005)(2:内蒙古农业大学水利与土木建筑工程学院，呼和浩特010018)摘要：摘要：为研究结冰对湖泊富营养化状态的影响，以内蒙古乌梁素海为研究对象，用“注射器”式采水器和冰钻分别采集水样和冰样，并测定总氮、总磷、COD(:i_、叶绿素a浓度、冰厚、水深和透明度等指标，运用分形理论评价模型对湖泊结冰前、后的富营养化等级进行综合评价.结果表明：乌梁素海湖泊结冰厚度与水深存在较好的负相关性,其相关系数为0.54;湖泊结冰后，水体的富营养化等级由富营养变为重富营养，表明结冰过程中，氮、磷等营养元素被排斥至冰下水体，即结冰过程对湖泊水体中的营养元素具有浓缩效应，导致冰下环境质量恶化，并促进营养元素向沉积物转移;但也可以利用该浓缩效应，从湖泊冰封期富营养化污染的特殊性入手,运用底泥疏浚和冰体-水体分离等工程技术手段，实现湖泊富营养化污染的治理.关键词：关键词：结冰;富营养化;分形理论;乌梁素海EffectoffreezingoneutrophicationinLakeUlansuhaiZHANGYan1,LIChangyou2,GAONing1,SHIXiaohong2&QIAOLingmin1(1：CivilEngineeringCollege,YantaiUniversity,Yantai264005,P.R.China)(2:WaterConservancyandCivilEngineeringCollege,InnerMongoliaAgriculturalUniversity,Huhhot010018,P.R.China)Abstract：Inordertostudytheeffectoffreezingonlakeeutrophication,LakeLlansuhai,locatedinInnerMongolia,wasselectedasthestudyobject.Theiceandwatersamplewerecollectedrespectivelybysyringewatersamplerandicedrill.Thetotalnitrogen,totalphosphorus,CODrr,chlorophyll-a,icethickness,waterdepthandtransparencyofeachsampleweremeasured.TheeutrophicstateofLakeLlansuhaibeforeandafterfreezingwereassessedbythemeansoffractaltheory.TheresultsshowedthattherewasagoodnegativecorrelationbetweenwaterdepthandicethicknessinLakeLlansuhai,andthecorrelationcoefficientwas0.54.Thetrophicstateofwaterbeforefreezingwaseutrophication,andchangedtoheavyeutrophicationafterfreezing.Theresultsalsoshowedthatnutrientelementssuchasnitrogenandphosphoruswereejectedtowaterduringtheperiodoficegrowth,thatistosay,theprocessoffreezinghadagoodconcentratingeffectonpollutantsinwater.Thiseffectalsocanmakepollutantsmigratefromwatertosedimentduringicegrowthprocess,whichmadethequalityofunder-iceenvironmentdeteriorate.Whiletheconcentratingeffectcanprovidetheoreticalbasisanddatasupportforthesedimentdredgingandice-waterseparatingduringice-onperiod.Keywords:Freezing;eutrophication;fractaltheory;LakeLlansuhai湖泊是重要的淡水资源之一，我国湖泊数量众多、分布广泛，但由于