筑坝拦蓄对河流活性硅迁移过程影响研究进展

Research progress on impact of damming and impoundment on the migration process of riverine reactive silicon

摘要

【目的】活性硅在特定生物组成中具有不可替代性，从而影响初级生产力和生态系统稳定。河流筑坝深刻改变水中营养物质生物地球化学过程，制约河流水文过程和生态系统的演化。为完善筑坝对河流硅生物地球化学循环的认识，【方法】在梳理相关研究的基础上，以河流活性硅迁移转化机制为突破口，从筑坝对河流活性硅的滞留效应及其造成的生态影响、筑坝后河流活性硅的迁移机制以及特殊筑坝模式下活性硅生物地球化学过程等方面进行阐述。【结果】筑坝加强了河流活性硅的滞留，造成生物组成结构改变等负面生态效应。岩石风化减弱、沉积作用与生物吸收转化加强以及分层异重流演变是影响活性硅迁移的重要因素，但在河流不同区域各效应重要程度有所差异。梯级筑坝河流中活性硅环境行为受多种复杂途径调控，生态调节坝修筑产生的“库中库”效应可能改变驱动活性硅循环的关键过程。【结论】全面揭示河流筑坝对活性硅具体影响机制仍有待深入研究，未来建议从动态监测与模型构建、多维度生态效应评估、分层异重流机制、跨区域对比以及不同调度模式下活性硅环境行为等方向加强研究。研究结果加深了筑坝对河流活性硅迁移转化过程的理解，可为河流筑坝的生态管理提供指导。

Abstract

[Objective] Reactive silicon is irreplaceable in certain biological structures, thereby influencing primary productivity and ecosystem stability. River dam construction profoundly alters the biogeochemical processes of nutrients in water, constraining river hydrological processes and ecosystem evolution. It is necessary to improve the understanding of the biogeochemical cycle of silicon in rivers through dam construction. [Methods] Based on a review of relevant studies, the migration and transformation mechanisms of riverine reactive silicon were taken as breakthrough points, with a focus on the retention effects of damming and its ecological impacts, the migration mechanism of reactive silicon after damming, and the biogeochemical processes of reactive silicon under specific damming patterns. [Results] Damming increased the retention of riverine reactive silicon, [Results]ing in negative ecological effects such as changes in biological community structure. Weakened rock weathering, intensified sedimentation and biological uptake and transformation, and the evolution of stratified density currents were key factors influencing reactive silicon migration, but the importance of each factor varied across different river regions. In rivers with cascade dams, the environmental behavior of reactive silicon was regulated by multiple complex pathways. The “reservoir-in-reservoir” effect caused by the construction of ecological regulating dams might alter key processes driving the reactive silicon cycle. [Conclusion] A comprehensive understanding of the specific mechanisms by which damming affects reactive silicon still requires further research. Future research is recommended to focus on dynamic monitoring and model development, multidimensional ecological impact assessments, mechanisms of stratified density currents, cross-regional comparisons, and the environmental behavior of reactive silicon under different operation patterns. The result deepen the understanding of the migration and transformation processes of riverine reactive silicon affected by dam construction and can provide guidance for the ecological management of river damming.

关键词

河流活性硅 / 筑坝拦蓄 / 迁移转化 / 生态调节坝 / 分层异重流 / 生物地球化学过程 / 影响因素 / 研究进展

Key words

riverine reactive silicon / damming and impoundment / migration and transformation / ecological regulating dam / stratified density current / biogeochemical process / influencing factors / research progress

基金资助

国家自然科学基金项目(42407108)

湖北省水利科研项目(HBSLKY202405)

中央级公益性科研院所基本科研业务费项目(CKSF2023299/ CQ)

中央级公益性科研院所基本科研业务费项目(CKSF20241010/ CQ)

国家重点研发计划(2023YFE0125600)