Analysis by numerical experiments of desalinization of a salt-affected paddy field using a rice husk underdrainage system
Analysis by numerical experiments of desalinization of a salt-affected paddy field using a rice husk underdrainage system
复制标题
稻壳欠排水系统脱盐稻田数值试验分析
DOI：
10.1007/s10333-019-00713-6
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发表时间：
2019
影响因子：
2.2
通讯作者：
Omachi Kana
中科院分区：
文献类型：
--
作者：
Inosako Koji;Saito Tadaomi;Omachi Kana
在季风气候中，盐不仅在旱地积累，而且在旱季也在稻田积累。由于水田的重力排水自然脱盐非常困难，因此需要排水设施来去除受影响水田的盐分。稻壳地下排水系统（RHUS）是一种适用的方法。虽然这一制度简单合理，但遗憾的是，缺乏实际执行这一制度的资料。在这项研究中，我们进行了数值场规模的实验与RHUS使用HYDRUS 2D/3D软件，以获得设计这样一个系统的信息。我们的研究结果阐明了排水口的大小，稻壳排水沟（RHD）的宽度，和RHD梯度上的排放量的土壤水/盐和咸水在稻田中的运动。研究结果表明：（1）排水口大小对系统的排水能力没有影响;（2）在相同的淋洗水量下，小宽度的RHD比大宽度的RHD排水量大;（3）由于RHD起到了从耕层向下层土壤运动的旁路作用，大宽度RHD从耕层去除的盐水量大于小宽度RHD;大坡度的RHD有利于增加盐渍土排水量，但作用不大，因此对于实际应用来说似乎是不必要的。
In a monsoon climate, salt accumulates not only in drylands, but also in paddy fields during the dry season. Because natural desalinization by gravitational drainage is very difficult in paddy fields, drainage facilities are needed to remove salts from affected paddy fields. A rice husk underdrainage system (RHUS) is one applicable method. Although this system is simple and reasonable, there is an unfortunate lack of available information for its practical realization. In this study, we conducted numerical field-scale experiments with an RHUS using HYDRUS 2D/3D software to obtain information for designing such a system. Our results clarified the effect of outlet size, rice husk drain (RHD) width, and RHD gradient on the amount of discharged soil water/salts and saline water movement in the paddy field. We summarized our results as follows: (1) outlet size did not affect the system’s drainage ability; (2) small-width RHD discharged saline soil water at a greater rate than large-width RHD when using the same amount of leaching water; (3) because the RHD worked as a bypass of saline water movement from the plow layer to the lower soil layer, the amount of saline water removed from the plow layer was larger with the large-width RHD than with the small-width RHD; and (4) the large gradient of the RHD was advantageous in increasing the amount of discharged saline soil water, but the effect was small, so it appears unnecessary for practical application.