基于HYDRUS模型的江苏如东盐渍土一维淋滤渗流试验研究

One-dimensional Leaching and Seepage Test of Saline Soil from the Coastal Areas in Rudong Based on HYDRUS Model

通过自行设计一维圆柱型淋滤渗流柱,采用原位回填装填盐碱土样,在人为设定降雨条件下,通过盐分传感器监测获取土壤水盐运移、渗滤液离子成分的监测数据。HYDRUS软件模拟水盐运移,含水量和盐分浓度的模拟结果表明模型可信度高,弥散度改变对土壤最终含盐量变化没有明显影响,但对在土壤干湿交替条件下不同阶段排盐量的比例分配有明显作用;当等温吸附系数整体降低时,土壤中盐浓度到达峰值所需时间减少,土壤排盐量增加。等温吸附系数较小的,对降雨量和降雨频率响应更明显,排盐效果更好。

In this paper a one-dimensional column apparatus was designed and saline soil samples from the coastal areas in Rudong County, Jiangsu Province were backfilled to study the temporal and spatial migration characteristics of the moisture and solute in the soil by monitoring the EC and potential as well as the chemical analysis of the leachate solutions, considering natural rainfall conditions. The results of models, simulated with HYDRUS package on water and salt transport, water content and saline concentration, demonstrated that the models was rela- tively reliable. Changes of disparity had no obvious influence on the final saltiness in soil, however, changes of disparity had an evident effect on the proportional allocation of salt-leaching at different phases under the condition of alternation of soil wetting and drying. When the isother- mal adsorption coefficient dropped, the interval that the saline density got the peak value decreased and the salt-leaching quantity increased. The less the isothermal adsorption coefficient was, the more obvious the reaction to the precipitation and frequency of precipitation was, the better the salt-leaching effect was.