拟除虫菊酯类农药环境行为与归趋模拟

本文以氯氰菊酯为主要研究对象,类比林冠截持降雨模型模拟农药施撒时的初始分配,参考降雨对叶面孢子的冲刷建立降雨量与农药叶面冲刷率的关系,在野外监测数据的基础上估算降解参数,成功模拟了单次降雨过程中氯氰菊酯的迁移与动态分布过程。在对单场降雨模拟的基础中,进一步考虑农药在土壤各相间的分布、溶解态和泥沙吸附态农药在地表水中的迁移过程,在长时间尺度上模拟了表层土壤中和植物叶面上农药含量的变化规律,估算溶解态和泥沙吸附态农药在地表径流中的迁移通量,预测了不同施药条件下农药在多介质环境中的迁移通量和环境介质内农药含量的动态变化过程。

Simulating the Environment Behavior and Fate of Synthetic Pyrethroids

Using cypermethrin as the object, through simulating pesticide initial distribution by analogy with rainfall interception model of forest canopy, referring to the relationship between rainfall and foliage wash-off pesticide rate based on the imitative spores washed-off by rainfall and estimating degradation parameters with field investigation data, the transport and dynamic distribution processes under one rainfall event were successfully simulated. Derived from pesticide transport modeling under one rainfall event, several significant processes including the phase-to-phase distribution between soil and water, pesticide dissolved in surface runoff and adsorbed on sediments were implanted into the model, which were crucial to pesticide transport behaviors in the long time scale. Finally, the model was used to simulate time-dependent dynamics of cypermethrin content in topsoil and on litchi leaves, the transport flux of the dissolved and sediment-adsorbed cypermethrin in runoff were also computed. Furthermore, the transport flux of cypermethrin in multi-media environment and the changes of its contents in each environment media under different application conditions were forecasted and discussed.