DataSheet1_Modelling the Fate of Pesticide Transformation Products From Plot to Catchment Scale—State of Knowledge and Future Challenges.docx

Transformation products (TP) of pesticides are found everywhere in the aquatic environment. Their dynamic formation and subsequent transport from agricultural fields to adjacent water bodies can be estimated by using environmental fate models, which is done in the registration process for plant protection products in the European Union. In this study, peer-reviewed applications of such models, the model complexity and their structure are documented and analysed. In total, 20 publications of 10 models – eight leaching models (GLEAMS, MACRO, RZWQM2, PEARL, PRZM, Pelmo, LEACHM, HYDRUS 1-D) and two catchment scale models (Zin-AgriTra, FRM) – were identified. The reviewed models greatly differ in their process complexity regarding the formation rate and the formation pathways of TPs.The major reason given for models failing to reproduce sampled TP concentrations in case studies was an erroneous substance transport, especially missing preferential flow simulation in soil. However, the contribution of TP formation processes to simulation uncertainty was not analysed at all in most of the studies. By comparing the structure of existing models, the state of knowledge on TP fate and requirements of TP fate assessment, the following recommendations were drawn: i) It is suggested that the models should be updated to reflect the current state of knowledge in process research, especially more complex transformation schemes and the formation of different TPs in different compartments, which was not included in most of the models. ii) Even though there are pesticide parent compound fate models at the catchment scale with a temporal resolution of one day, none of these models is able to simulate TP fate. Such models would enable scientists and authorities to estimate the environmental fate of TPs at the larger catchment scale or the regional scale. iii) To get over the assessment of the huge number of TPs formed in the environment, an integration of Quantitative Structure Properties Relationship models predicting TP fate characteristics, TP pathway prediction models and environmental fate models is suggested. This would allow for a largely automated and comprehensive assessment of the fate of a pesticide parent compound and all its TPs for regulatory purposes.农药转化产物（Transformation Products, TP）广泛存在于水生环境中。其动态生成与随后从农田向邻近水体的迁移过程，可通过环境归趋模型进行估算——这一流程是欧盟植物保护产品登记过程中的必要环节。本研究对经同行评议的此类模型应用案例、模型复杂度及其结构进行了整理与分析。本次研究共识别出10种模型的20篇相关文献，其中包含8种淋溶模型（GLEAMS、MACRO、RZWQM2、PEARL、PRZM、Pelmo、LEACHM、HYDRUS 1-D）与2种流域尺度模型（Zin-AgriTra、FRM）。所综述的模型在TP生成速率与生成路径相关的过程复杂度上存在显著差异。在案例研究中，模型无法复现实测TP浓度的主要原因被归结为物质迁移模拟存在误差，尤其是土壤中优先流模拟的缺失。但绝大多数研究均未分析TP生成过程对模拟不确定性的贡献程度。通过对比现有模型结构、TP归趋相关的认知现状以及TP归趋评估的需求，本研究提出以下建议：① 建议对现有模型进行更新，以反映过程研究领域的最新认知进展，尤其是纳入多数模型尚未覆盖的复杂转化路径，以及不同环境隔室中不同TP的生成过程；② 尽管当前已存在时间分辨率为1日的流域尺度农药母体化合物归趋模型，但尚无一款模型能够模拟TP归趋。此类模型可帮助科研人员与管理部门在更大的流域尺度或区域尺度上估算TP的环境归趋；③ 为解决环境中生成的海量TP的评估难题，建议整合可预测TP归趋特征的定量结构性质关系（Quantitative Structure Properties Relationship, QSPR）模型、TP路径预测模型与环境归趋模型。此举可实现农药母体化合物及其所有TP的归趋的自动化、系统化评估，以满足监管需求。