草型富营养化湖泊淤积死亡加速机制研究

富营养化湖泊的治理重点依然是氮磷营养盐控制，但是，草型富营养化湖泊植物残体淤积填埋极大的加快了湖泊淤积死亡速度，急需从河流动力学的角度研究其淤积机制，切断湖泊营养盐內源循环。项目以乌梁素海为研究基地，采用围隔原位分解网袋实验、微型湖泊生态实验和高精度循环水槽实验技术，探索基于生物化学分解和紊动输运机制的淤积响应公式，研发考虑植物残体淤积的草型富营养化湖泊数值模拟模型。模型可以准确模拟冰封期-凌汛补水期-春灌退水期植物残体生物化学分解和复杂水动力输运耦合作用下湖泊的淤积变化机制。项目研究不仅为草型富营养化湖泊淤积治理提供科学依据和技术支撑，还从动力学角度为富营养化湖泊内源污染治理提出新的思路。

Nutrients control is still considered as the core of eutrophic lake treatment. However, deposition of the macrophyte debris not only aggrandize the nutrient accumulation, but also speeds up the dying processes of the lake. Therefore, it is of great significance to study the sedimentation mechanism from the perspective of the river dynamics. Based on the in-situ decomposing mesh bag experiment, micro-ecological experiment system and fluid dynamics experiment in flume, our project aims to find the numeric relation between the sedimentation and the bio-chemical activity, the dynamic transport behavior. An eco-environmental model considering the sedimentation and transport of macropyte debris in macrophyte-dominated eutrophic lake is to be established. This model can be used to simulate complex sedimentation process due to the combined effect of eco-chemical and dynamic process during the ice-on season, the ice-flood season and the spring-irrigation season. Our study not only provides scientific basis and technical support for the sedimentation control in macrophyte-dominated eutrophic lakes, but also puts forward new ideas for the treatment of eutrophic problems.