Control of Water and Solute Movement in Soil using Geo-Textile

使用土工织物控制土壤中的水和溶质运动

• 批准号: 06660301
• 负责人: KIYOSAWA Hideki
• 金额: $ 1.41万
• 依托单位: Mie University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660301/
• 关键词: Geo-textile; Soil water movement; Solute transport; Solute accumulation; Farm irrigation; 不飽和透水係数; 数値シミュレーション

A buried geo-textile was used to investigate the potential to control the upward migration of solutes under cvaporation from a shallow water table.First, experiments about water and solute distribution measuremants during evaporation using soil columns were conducted. From the data, soil water flux and solute flux through the geo-textile were calculated. The unsaturated conductivity of geo-textile decreased rapidly to about 1/1000 as that of the soil when the surrounding soil suction increasd to only 20cm. Also, the solute flux was proportionate to water flux and was controlled by convection. So, liquid water movement was concluded to be important in controlling solute tansfer to the soil surface.Next, using the characteristics of the soil and the geo-textile obtained in the column experiments, numerical simulation was carried out. Under field conditions of cvaporation from a shallow water table, soil water flux was usually approximated by the product of two functions of time and depth. When geo-textile was buried, the ground water condition makedly afffected the patters of water flux distribution. Deriving the proper distribution functions, an approximate solution was obtained. Using this approximate solution and the numerical simulation, the depth, the thickness, and the characteristics of geo-textile buried considerably affected the soil water flux and solute tranfer.

为了研究埋地土工织物对浅层地下水蒸发过程中溶质向上运移的控制作用，首先进行了土柱蒸发过程中水分和溶质分布的测量实验。从数据，土壤水通量和溶质通量通过土工织物计算。当周围土壤吸力增加到20 cm时，土工织物的非饱和导水率迅速下降，约为土壤的1/1000。此外，溶质通量与水通量成正比，并受对流控制。因此，液态水的运动是控制溶质向土壤表面迁移的重要因素。其次，利用室内土柱试验得到的土和土工织物的特性，进行了数值模拟。在浅水位蒸发的田间条件下，土壤水通量通常用时间和深度两个函数的乘积来近似。土工布埋设时，地下水状况对地下水通量分布模式有较大影响。通过推导适当的分布函数，得到了近似解。利用该近似解和数值模拟结果，研究了土工织物的埋深、厚度和特性对土壤水分通量和溶质运移的影响。

项目成果

清沢秀樹: "地下水位が浅い土層内で生じる排水時の土壌水分変化を表す近似解" 農業土木学会論文集. (印刷中). (1996)

Hideki Kiyosawa：“表达浅层地下水位土壤层排水过程中土壤湿度变化的近似解”，日本农业和土木工程师学会会刊（1996 年出版）。

Hideki KIYOSAWA: "Approximate Solutions for the Soil Water Movement during Drainage under a High Groudwater Table Condition" Transaction of Japanese Society of Irrigation, Drainage, and Reclamation Engineering, accepted. (in press). (1996)

Hideki KIYOSAWA：“高地下水位条件下排水过程中土壤水分运动的近似解决方案”，日本灌溉、排水和复垦工程学会会刊，已接受。