面向流量管理的水动力对淡水藻类影响的概念机制

J_LakeSci．(湖泊科学)，2015，27(1)：24—30http：#www．jlakes．org．E—mail：jlakes@niglas．ac．cn@2015byJournalofSciences面向流量管理的水动力对淡水藻类影响的概念机制陈瑞弘，李飞鹏，张海平，陈玲’，赵建夫，黄子寒(1：同济大学环境科学与工程学院，上海200092)(2：复旦大学环境科学与工程系，上海200433)摘要：许多证据表明缓慢的水动力条件是水华暴发的重要诱因，尽管以临界流速和水体置换为基础的流量管理实践在水华控制中已见成效，但受限于水动力对藻类生长小生境的干扰机制尚不明晰，长期的流量管理实践效果并不理想．在长期野外观测、围隔实验和室内模拟等一系列研究的基础上，以现有水动力对藻类影响机制的讨论为依据，从细胞学角度提出了水动力对藻类生长影响的3种不同的概念机制，即低强度的水力扰动导致藻细胞外扩散层厚度变薄，有利于周边水体向藻细胞输送营养物质，促进藻类生长；中等强度的水力扰动导致藻类营养盐吸收及光合作用能力受损，抑制藻类生长；高强度的水流剪切导致藻细胞壁破损．基于该机制认为流量管理中临界流速应分别从水体置换和细胞学两方面考虑．研究结果可为流量管理中控制藻类水华暴发和维持水体水质的策略提供重要的理论支持．关键词：水动力；水华藻类；临界流速；流量管理；概念机制Conceptualmechanismofhydrodynamicimpactsonfreshwateralgaeforflowmanage—mentCHENRuihong，LIFeipeng，ZHANGHaiping，CHENLing，ZHAOJianfu’＆HUANGZihan2(1：CollegeofEnvironmentalScienceandEngineering，TongjiUniversity，Shanghai200092，P．R．China)(2：DepartmentofEnvironmentalScienceandEngineering，FudanUniversity，Shanghai200433，P．R．China)Abstract：Numerousstudieshaveshownthatlowflowconditionisthemaintriggerofalgaebloomandflowmanagementiswidelyacknowledgedasastrategyforinhibitingbloomdevelopmentbasedoncriticalflowvelocityandreplacement．Duetotheunderlyinginterventionmechanismisstillnotclear，long-termpracticesofflowmanagementarenotveryefective．Basedontheresearchpro-gressandaseriesofstudiesthroughlong—termobservation，enclosureandlaboratoryexperiments，wepresenttheconceptualmech—anismthatthereexistedthreediferentmechanismsofhydrodynamicimpactsonfreshwateralgae：(1)lowturbulentflowresultsinthethicknessofcelldifuselayerthinnerinfavorofnutrientstransportfromwaterphasetoalgaecell，whichispreferredbyalgaegrowth；(2)mediumturbulentflowisharmfultonutrientsabsorptionandlightavailabilityofalgaeandinhibitsthealgaegrowth；(3)highshearforcecandamagethealgaecellwalls，whichareindividuallydeterminantindifferentlevelsofflowintensity．Ac-cordingtotheories，criticalflowvelocityshouldbeappliedfromtwodifferentaspectsofwaterreplacementandcytologyinflowmanagement．Theresultswillbeofgreatscientificsignificanceinordertocontrolalglebloomandremainthewate