State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Sci Total Environ. 2023 Jan 10;855:158887. doi: 10.1016/j.scitotenv.2022.158887. Epub 2022 Sep 20.
Many studies focus on the transport of plastic from rivers to oceans while little attention was paid to the plastic transport in the upper reaches of rivers. Transport process of plastic from upstream to downstream in the whole river basin scale is still poorly understood. In this work, five sections in the upper reaches of the Yangtze River were investigated to characterize the features of plastic transport. Plastic abundance and flux were 293 to 156,667 n/m and 1.2 to 34,711 g/s, respectively. Plastic flux peaked at or right after the first flood peak in most sections, but plastic abundance was the highest in the normal or low water period. The first flood peak caused a temporary rise of plastic flux that last a short duration. Transport of plastic was not limited to water surface, and the Three Gorges Dam showed a peak elimination effect on plastic transport. Annual discharge of plastic was 1392 to 9532 tons and 6.2 × 10 to 175 × 10 particles at different sections. An increasing trend was observed for both plastic mass and quantity going downstream. Results showed that river plastic flux is highly variable and influenced by the dam, which should be considered in future to develop better monitoring strategies and to further improve the model.
许多研究都集中在塑料从河流向海洋的输送上，而对河流上游的塑料输送则关注甚少。整个流域尺度上的塑料从上游到下游的输送过程仍了解甚少。在这项工作中，对长江上游的五个河段进行了调查，以描述塑料输送的特征。塑料丰度和通量分别为 293 至 156670 个/米和 1.2 至 34711 克/秒。在大多数河段，塑料通量在第一次洪峰时或之后达到峰值，但在正常或低水期塑料丰度最高。第一次洪峰导致了塑料通量的暂时上升，持续时间很短。塑料的输送并不局限于水面，三峡大坝对塑料输送有一个峰值消除效应。在不同的河段，每年的塑料排放量为 1392 至 9532 吨，颗粒数为 6.2×10 至 175×10。下游的塑料质量和数量都呈现出增加的趋势。结果表明，河流塑料通量变化很大，受大坝的影响，在未来应考虑这一点，以制定更好的监测策略，并进一步改进模型。
