非反应性物质在土壤中的迁移及其参数确定

采用一维对流－水动力弥散方程研究了非反应性化学物质在土壤中的迁移行为。通过实验研究了土壤团聚体大小和孔隙水流速对非反应物质在土壤中迁移的影响。结果表明，对流－水动力弥散方程能较好地预报氚（＾３Ｈ２Ｏ）的穿透英线和迁移行为，随着团聚体由小变大，＾３Ｈ２Ｏ在其土柱中的穿透曲线的溶质出流提前，而淋洗结果推迟，峰值变小，最佳拟合Ｄ值由小变大。流速增加，Ｄ值增大，扩散现象加剧，Ｄ和流速呈正比。这为进一步研究

TRANSPORT OF NONREACTIVE SOLUTE IN SOIL AND THE DETERMINATION OF MODEL PARAMETERS

The classical one-domain model with convection-dispersion equation was used in this study for describing a nonreactive solute transport in soil.By the experimental studies on the effect of soil aggregate size and pore water velocity on the transport of nonreactive solute in soil column,it was found that:tritium breakthrough curves could be well predicted by convection-dispersion equation;with the increase of aggregate size,early breakthrough,tailing and small peak were more pronounced by tritium breakthrough curves in soil column,best fitted D value increased as well;and D was proportional to pore water velocity in this study,and dispersion increased with the increase of pore water velocity,which is of great importance for studying the transport of reactive solute in soils and for predicting the fate of agricultural chemicals in field conditions.