山地土壤表层水溶性有机物淋溶动力学模拟研究

测定了伊春河流域河水、井水、坡面漫流、土壤淋溶液等样品中的水溶性有机物含量，据此结果建立了河水溶解态有机物来源的概念模型。并根据不同流速条件下土壤水溶性有机物淋溶模拟实验的结果，探讨了水溶性有机物从山地土壤中淋溶的动力学过程。研究发现，吸着在土壤有机－矿质复合体表面的水溶性有机物的淋溶包括三个连续的动力学过程：即从复合体表面进入土壤毛管水的解吸作用，自土壤团粒结构内部转移到土壤重力水中的扩散和相迁移过程，以及被流动相携带淋溶的对流过程。这一物理模型可以表述为包括三个加和项的简单表达式，模型中的迁移速率常数与流动相线速度的某一方次成正比。

Leachation kinetics of water soluble organic carbon from surface horizon of upland soil

Contents of dissolved organic carbon in various water samples of river,well,surface runoff,and soil leachate from Yichun River Basin have been measured.A conceptual model for the origin of dissolved organic in the river water was developed.The kinetics of leachation process of water soluble organic carbon from surface horizon of upland soil was investigated based on soil column leachation experiments at various flow rates.It was demonstrated that the leachation of the water soluble organic carbon sorbed on the surface of organic mineral complex occur in three steps of a) desorption from the surface of the complex into soil capillary pore water within granular structure; b)transfer into the gravitational pore water between granular aggregates through molecular diffusion and phase transfer,and c)being carried out of the soil matrix through convection flow.An equation including three corresponding additive terms was employed to model the process.The impact of flow rate on transfer coefficient constants was discussed.