Location: Water Quality and Ecology ResearchTitle: Tiered approaches in analyzing rice field pesticide fate and transport for ecological risk assessment Author
|Wang, Ruoyu - University Of California, Davis|
|Yuan, Yongping - Environmental Protection Agency (EPA)|
|Luo, Yuzhou - University Of California, Davis|
|Pitchford, Ann - Environmental Protection Agency (EPA)|
|Bingner, Ronald - Ron|
|Denton, Debra - Environmental Protection Agency (EPA)|
|Yen, Haw - Texas A&M University|
|Zhang, Minghua - University Of California, Davis|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 4/30/2018
Publication Date: 7/31/2018
Citation: Wang, R., Yuan, Y., Luo, Y., Pitchford, A., Bingner, R.L., Denton, D., Yen, H., Zhang, M. 2018. Tiered approaches in analyzing rice field pesticide fate and transport for ecological risk assessment. Book Chapter. 347-377. https://doi.org/10.1021/bk-2018-1283.ch016.
DOI: https://doi.org/10.1021/bk-2018-1283.ch016 Interpretive Summary: Pesticide appliPesticide application in cropland has the potential to be harmful to ecological health, such as through toxicity to non-target organisms. Ecohydrological models are deemed a useful tool to study the fate and transport of pesticides in the Analysis phase. A sequential evaluation approach was used so modelers can expend resources only on concerns that warrant additional evaluation. Rice paddies have unique hydrological conditions compared to other field crops. Many models are not suitable for rice fields for various levels of risk assessment, because they lack modules to correctly represent the unique hydrological and water quality processes in paddy areas. For watershed level assessment, especially for watersheds dominated by rice fields, applicable models include Paddy-Large, RICEWQ-RIVWQ, AnnAGNPS and PCPF-1@SWAT. A well-calibrated model can be used for scenario analysis to explore the effectiveness of mitigation strategies in controlling pesticide pollution, or providing continuous exposure data to evaluate ecological risk. The ecological risk assessment approach presented in this study is not only suitable for evaluating pesticide impacts in rice fields, but also for other landuse which is influenced by pesticide applications.
Technical Abstract: Pesticide application in rice fields is essential to alleviate pest stress and improve annual yield. However, water quality deterioration and other ecological problems may result from pesticide usage. Modeling is deemed a powerful method to understand the fate and transport of agrochemicals. However, many models fail to reflect the uniqueness of the rice growing environment, which limits the utility of simulation results for eco-risk assessment. In this chapter, we reviewed tiered approaches in analyzing the fate and transport of pesticides applied in rice fields using models. Tiers, based on model complexity, range from the rudimentary compartment level to the higher watershed scale, which is considered more realistic for characterizing hydrological/biological/physiochemical processes. Mathematical approaches are introduced to characterize ecological risks, after exposure is well-captured by the appropriate rice modeling tier. Ecological risk assessment starts from a simple deterministic risk quotient. It also can be relatively complicated, when the probability distributions of pesticide exposure and toxic effects are included. The ecological risk assessment approach presented in this chapter is not only suitable for evaluating pesticide impacts in rice fields, but also for other landuse which is influenced by pesticide applications.