Dataset underlying the publication: Estimating Plastic Export from Estuaries into the Sea Using a Mass-balance Model

Estuaries act as an interface between rivers and the sea, and therefore play a key role in transporting plastic to the sea. However, plastic transport in estuaries is complex and estuary-to-sea export is still very uncertain. This study presents a plastic mass-balance model that can be applied to specific estuaries, and produces export estimates similar to previous studies. The daily plastic export from estuary to sea was estimated to be 290 kg for the Rhine-Meuse Estuary (RME), and 19,431 kg for the Saigon Estuary, where the discharge into the sea is 3.5 times larger for the RME, compared to the Saigon Estuary. Due to limited discharge measurements for the Saigon Estuary, the yearly plastic export could only be estimated for the RME, corresponding to 13,300 kg. These estimates fall within the uncertainty range of previous studies. Deposition and remobilization resulted in the largest model fluxes, with magnitudes of 20 t/d for the RME and 430 t/d for the Saigon Estuary. At the same time, the model is most sensitive to the uncertainty in parameters related to deposition. Our results demonstrate that with the right measurements, making reliable estimates of estuary-to-sea export is possible. However, uncertainty in plastic transport processes, like deposition and remobilization, has a large impact on the uncertainty of parameters and the model. Automated sensors, targeted field experiments, and improved model structure can enhance export estimates and further improve understanding of plastic dynamics in estuaries, bringing us closer to strategies that reduce the environmental footprint of plastic, and protect ecosystems and human health.<br>This dataset includes the Mass-balance Model script in R, along with all other functions and data used. This publication has not yet been published. The study underlying the future publication can be found in the following master's thesis: https://edepot.wur.nl/695475.

河口作为河流与海洋之间的过渡界面，在塑料向海洋输运的过程中扮演着关键角色。然而，河口内的塑料输运过程极为复杂，河口向海的塑料输出量至今仍存在较高不确定性。本研究提出了一款可适配特定河口场景的塑料质量平衡模型（mass-balance model），其输出的塑料输出估算结果与既往研究的结论较为吻合。针对莱茵-默兹河口（Rhine-Meuse Estuary，简称RME），模型估算其每日向海塑料输出量为290千克；针对西贡河口，该数值达19431千克——而莱茵-默兹河口的入海径流量为西贡河口的3.5倍。由于西贡河口的径流量监测数据较为匮乏，仅能对莱茵-默兹河口的年塑料输出量进行估算，结果为13300千克。上述估算结果均落在既往研究的不确定性区间内。沉积与再悬浮过程是模型中通量规模最大的两项过程，莱茵-默兹河口的相关通量达20吨/日，西贡河口则为430吨/日。与此同时，该模型对与沉积过程相关的参数不确定性最为敏感。研究结果表明，只要获取合理有效的监测数据，即可实现河口向海塑料输出量的可靠估算。但塑料输运过程（如沉积与再悬浮）中的不确定性，会对参数及模型整体的不确定性产生显著影响。自动化传感器、针对性野外实验以及优化后的模型结构，可提升塑料输出量的估算精度，进一步深化对河口塑料动力过程的认知，助力我们制定更有效的策略以降低塑料的环境足迹，保护生态系统与人类健康。

本数据集包含R语言编写的质量平衡模型脚本，以及研究中使用的全部其他函数与配套数据。该研究成果尚未正式发表，支撑该待发表成果的相关研究可通过以下硕士学位论文查阅：https://edepot.wur.nl/695475。