【摘要】 河道型水库建成后,支流库湾水动力学条件改变,水流减缓,遇到适宜环境条件和充足营养条件后,易产生水华,从而给水生态系统带来不利影响.为调查不同水动力学条件对水华生消的影响,以流速为表征指标,在封闭循环模型中设置不同水体流速,控制环境条件和营养条件,开展室内水华生消模拟试验.结果表明:在一定范围内(<0.4 m·s-1),流速增大有利于藻类生长和水华暴发;不同流速下,藻类生长均符合微生物生长的一般规律,即经迟滞期、指数期到稳定期,最后达衰退期,水华相应出现暴发高峰和消退低谷.表明一定范围内(<0.4 m·s-1)水流流速的提高并不能抑制藻类生长和水华暴发,与水华暴发有关的水动力学条件的表征指标有待深入研究.更多还原

【Abstract】 The construction of a river-type reservoir will normally cause a change of hydrodynamic condition and a decrease of flow velocity in branch bays,leading to the formation of algae bloom when appropriate environmental conditions and sufficient nutrient supply are encountered,and thereby,causing the deterioration of fluvial ecosystem therein.To investigate the effects of hydrodynamic conditions on algae bloom,flow velocity was taken as the characteristic parameter,and controlled differently in the closed and recurrent models under identical environmental and nutrient conditions.The results showed that the increase of the flow velocity in a range of <0.4 m·s-1 would accelerate the growth of algae and the occurrence of bloom.Under the conditions of different flow velocity,the growth of algae was similar to the common process of other microorganisms,namely,lag phase firstly,exponential phase secondly,stationary phase thirdly,and decline phase lastly.Accordingly,the outbreak peak and regression floor of the algae bloom would occur.Therefore,the increase of flow velocity in a range of <0.4 m·s-1 would not inhibit the growth of algae and the occurrence of bloom.The effective characteristic parameter of the hydrodynamic conditions would be studied in depth in future.更多还原