Pesticide Groundwater Risk Assessment with China-PEARL and PRZM-GW Model in Weifang City Scenario

China-PEARL is a pesticide exposure model that has been applied to pesticide groundwater risk assessment in China. Weifang City scenario of PRZM-GW was established based on Weifang City scenario data of China-PEARL. PECs(predicted environmental concen-tration)of 56 pesticides applied on 5 crops in 145 application methods were calculated by both China-PEARL and PRZM-GW. The risk characterization results with RQ(risk quotient)showed that the groundwater risk of 8 pesticides in 13 application methods was unacceptable.Among them, carbendazim and fomesafen were assessed as unacceptable groundwater risk by both models. The comparison of PECs of the two models indicated that the evaluating results of PRZM-GW and China-PEARL were highly consistent. It verified the credibility of China-PEARL. The analysis on the factors affecting the outputs of the two models revealed that Koc had the biggest effect on PECs. Koc>400 L·kg -1could be adopted as a preliminary determination index of PEC<0.1 μg·L-1.The PECs showed clearly linearly correlation with logged soil aer-obic half-life. The PECs of the both models increased steeply when soil aerobic half-life>10 d. Hydrolysis half-life was used in PRZM-GW and determined the variation trend of pesticide concentration in groundwater. Solubility in water was an input option of China-PEARL which influenced lightly on PECs