回流使大河的支流成为"沉"
Bingfen Cheng1, Yuan Zhang2, Rui Xia3
1State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; College of Emergency Technology and Management, North China Institute of Science & Technology, Langfang, 065201, China.
Water research
|July 5, 2024
概括
河流交汇处的排放率控制着转移,较低的比率会导致沉积,较高的比率会释放,增加藻类繁殖的风险. 了解这些模式是管理大型河流生态系统的关键.
科学领域:
- 环境科学 环境科学
- 水文学的水文学
- 地质化学 地质化学
背景情况:
- 大型河流的合流创造了复杂的水文条件,改变了地球化学过程.
- 这些系统中的营养物质转化机制,特别是,尚未完全理解.
研究的目的:
- 研究水力动力学特征及其对汉河下游转移的影响,受长江回流影响.
- 建立一个水力动力学水质模型来分析这些相互作用.
主要方法:
- 利用水力动力学水质模型来模拟河流流和水质.
- 定义了排放比率 (汉河流量/长江流量) 作为滞水效应的指标.
- 确定了三个交汇模式:混合 (>0.08),回流 (0.010.08) 和入侵 (<0.01).
主要成果:
- 排放率直接影响了回水区的范围和水位在水合点.
- 的迁移主要是由颗粒 (LOP,DOP) 的沉积.
- 侵入模式扩大了滞水区,改变了物种 (增加了PO4^3-),并显著提高了水位.
结论:
- 汉河下游在排放比率为0.01-0.08的情况下充当水槽,可能会加剧污染.
- 春季的高排放率会导致沉积物释放,增加藻类繁殖的风险.
- 研究结果为全球大型河流系统的生态管理提供了洞察力.
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