流量坦化河段着生藻“水华”水流调控因子研究

由于蓄水和下泄流量控制，水坝以下河流流动模式改变，流量坦化，水流趋于稳定，高流量事件的幅度和频率减少，造成了河流中生物群落自然季节演替的丧失，坝下流量坦化河段着生藻“水华”时有发生。国内外研究表明，水流调控是一种新型调控河道内着生藻“水华”的有效技术，但在水流因子影响着生藻生物量的作用机制、水流控藻机理等方面，有待于进一步探讨。针对以上问题，选择澎溪河发生着生藻“水华”的典型流量坦化河段为研究区域，研究着生藻类群落结构的时空变化特征，界定着生藻类“水华”的阈值，开展水流对着生藻类作用原位试验，探讨水流要素与着生藻类相关关系，解析出调控着生藻类“水华”关键性因子。本研究成果可为流量坦化河段内着生藻类“水华”调控提供科学依据，也可为流量坦化河段的环境流量设定提供参考，亦可以为河流生态修复的研究奠定基础。

Biotic communities are often subjected to altered flow patterns below dams as a result of water storage and controlled releases. The provision of stable flows in many regulated rivers has resulted in the loss of natural seasonality and variability, and the magnitude and frequency of high flow events are frequently diminished. However, seldom have researchers studied this technique and its regulation mechanism, let alone to the regulation of key flow components. Based on above problems, field investigation, experimental methods and theoretical analysis are used to study the spatial-temporal variation of attached algae biomass, evaluate the threshold value of algal boom in this study. The correlation between the algal boom and flow components is also studied by conducting in-situ experiments with the aim of finding key factors in controlling the algal boom. Achievements in this study can provide scientific basis in regulating algal boom in stable flow rivers, improve the evaluation of environmental flow and lay the foundation of river restoration.