巢湖快速变化风浪场及其环境效应

Fast-changing wind waves and their environmental effects in Lake Chaohu

浅水湖泊风浪过程对于湖泊生态系统具有重要的意义.基于巢湖风场、风浪和水环境参数同步高频观测结果,详细分析了快速变化风场下的风浪快速变化特征及其对湖泊水环境的影响特征.浅水湖泊风浪的有效波高和平均波周期均随风速的快速变化有较好的同步响应规律.在风速快速衰减阶段,相较有效波高,波周期有更好的稳定性.湖泊水体pH、水温、溶解氧会快速响应风浪的变化,随着风浪强度增强,对水体浊度、总磷浓度以及藻密度和生物量的扰动影响逐渐呈现.强烈的风浪扰动引起水体浊度变化的滞后时间可达3 d.快速变化的风浪场下,风浪的强烈扰动会改变水体固有的理化参数分布特征,扰动藻类常规的水体分布规律,风浪强度是造成差异的主要因子.

Wind waves in shallow lakes are of great significance to lake ecosystems.Based on the synchronous high-frequency observation data in Lake Chaohu,the fast-changing characteristics of wind waves and their impacts on the water environment were analyzed in detail.The significant wave height and the average period of wind waves had a good synchronous response with the wind speed.In the phase of wind speed fast decline,the wave period has better stability than the wave height.The pH,water temperature,and dissolved oxygen will respond quickly to the changes of wind waves.As the intensity of wind waves increasing,the disturbance of water turbidity and total phosphorus concentration gradually appeared.The lag time of water turbidity changes caused by strong wind waves disturbance could reach 3 d.Strong wind waves disturbance would change the inherent distribution characteristics of physical and chemical parameters and the regular distribution of algae under fast-changing wind wave,indicating that the intensity of wind waves is the primary factor causing this difference.