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。%Numerous studies have shown that low flow condition is the main trigger of algae bloom and flow management is widely acknowledged as a strategy for inhibiting bloom development based on critical flow velocity and replacement .Due to the underlying intervention mechanism is still not clear ,long-term practices of flow management are not very effective .Based on the research pro-gress and a series of studies through long-term observation, enclosure and laboratory experiments, we present the conceptual mech-anism that there existed three different mechanisms of hydrodynamic impacts on freshwater algae:(1) low turbulent flow results in the thickness of cell diffuse layer thinner in favor of nutrients transport from water phase to algae cell ,which is preferred by algae growth; (2) medium turbulent flow is harmful to nutrients absorption and light availability of algae and inhibits the algae growth;(3) high shear force can damage the algae cell walls, which are individually determinant in different levels of flow intensity.Ac-cording to theories, critical flow velocity should be applied from two different aspects of water replacement and cytology in flow management.The results will be of great scientific significance in order to control algle bloom and remain the water quality in flow management.
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