受水库调度带来的扰动影响,河道型水库支流库湾河口底泥营养盐释放为水体富营养化和水华暴发增加了风险。文章通过在香溪河库湾河口采集底泥和水样,室内模拟扰动条件下,藻类外吸收源、扰动及底泥-水界面浓度梯度对底泥营养盐释放的影响。结果表明:扰动及外吸收源并存时,底泥氮磷释放量增大;扰动作用对磷释放影响较底泥-水界面浓度梯度弱,但对氮释放影响较底泥-水界面浓度梯度影响大;底泥释磷量随底泥-水界面浓度梯度升高而增大,释氮量则受其影响较小。三峡水库泄水和水华暴发、藻类大量繁殖将促进香溪河库湾底泥营养盐释放。
Nutrition released from sediment in the estuary of branch bay in stream-type reservoir will raise the risk of eutrophication and algae bloom with the dispatching of reservoir. The sediments in the estuary of Xiangxi River Bay was sampled, with simulation of disturbance of dispatching in laboratory to study the effect of algae exterior-absorption resource, disturbance and concentration profile between interface of sediment and overlying water on the nutrient release. Results showed that disturbance and algae exterior-adsorption resource would accelerate the release rate and quantity. Disturbance had less impact on the release of phosphorus than concentration profile between interfaces of sediment and overlying water, inversely, the impact of disturbance on the release of nitrogen was better than that of the concentration profile. Content of phosphorus released from sediment would increase with the risen of concentration profile, while the content of nitrogen release had little correlation with concentration profile between interface of sediment and overlying water. Flood discharge of Three Gorges Reservoir, formation of algae bloom and reproduction of algae will accelerate the release of nutrient from the sediment to water body in Xiangxi River Bay.