Simulation of Solute Transport in Heterogeneous Soils. Volume 1. Conjunctive Application of Physically Based and System Modeling Approaches

摘要

Agricultural chemicals developed to enhance production and/or control undesirable pests have been extensively used throughout the country because of their effectiveness and economic feasibility. On the other hand, the residuals of all the applied chemicals might be able to enter the groundwater aquifers, which happen to be the main water source. Such processes as volatilization, chemical and biological decay, percolation, and diffusion and dispersion control the fate and distribution of the applied chemicals leaching in the soil, as well as in groundwater aquifers. Mathematical models that predict the contamination potential of chemical inputs on the soil surface or in the upper unsaturated soil zone are an increasingly important and useful management tool. Mathematical models can be formulated by following physically based and system approaches. In the study, models based on these approaches were developed to simulate Fenamiphos transport in highly aggregated Hawaiian Oxic soils. Concentration profiles calculated with these models showed rather close similarity to and agreement with measured profiles. Conjunctive use of these models revealed their intrinsic relationship and the consistency between them.