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Environmental Informatics Archives

ISSN 1811-0231 / ISEIS Publication Series Number P002

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  Paper EIA06-010, Volume 4 (2006), Pages 93-103 = complimentary

PeSM: A One-Dimensional Finite-Difference Model for Simulating Pesticide Subsurface Leaching Process

B. Chen1*, X. S. Qin2 and B. Y. Zhang3

1. Faculty of Engineering & Applied Science, Memorial University of Newfoundland St. John's, NL, Canada, A1B 3X5. *Corresponding author: bingchen@engr.mun.ca.

2. EVSE, Faculty of Engineering, University of Regina, Regina, SK, Canada, S4S 0A2.

3. Department of Civil Engineering, Dalhousie University, Halifax, NS, Canada, B3J 1Z1.

 

Abstract

Pesticide pollution has been a pervasive concern across the world in recent years. The major pathways of pesticide transport in the environment include emission to the atmosphere, loss through surface runoff and leaching to subsurface. Among them, the leaching process can significantly contribute soil and groundwater pollution. To improve pesticide management and water pollution control, it has become an important task for environmental engineers and managers to quantify pesticide transport and fate in subsurface. This study attempted to develop a mathematical model (PeSM) for simulating pesticide leaching processes within unsaturated zone in agricultural lands. The proposed model was based on the advancement of the commonly used models such as MACRO and PRZM-2. The major pesticide transport processes in soil, such as degradation, root uptake, volatilization, erosion, adsorption, and evapotranspiration were considered into the modeling framework. The numerical techniques for solving the differential equations were discussed. A backward-difference implicit scheme to simulate chemical transport processes was employed to solve the discretized transport equation for the new dissolved pesticide concentration at the end of the time step. Furthermore, the Jury's boundary layer approach was incorporated into the PeSM to simulate vapor-phase pesticide movement past the soil surface. The next step of the study will conduct a case study to validate the developed model and then applied it to solve the real-world pesticide leaching problem.


Keywords: agricultural land, groundwater, leaching, pesticide, simulation, soil

 

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