惠民县微咸水灌溉区土壤水盐运移数值模拟及分析

Numerical Simulation and Analysis of the Transport of Soil Water and Salt in Brackish Water Irrigation Area of Huimin

为合理利用水资源、保证地下水盐环境,以惠民县桑落墅项目区为研究对象,运用HYDRUS软件,构建了土壤水盐运移数值模型,并在微咸水灌溉条件下对该地区土壤水盐运移进行了数值模拟和分析。结果表明,HYDRUS模型可以较好对土壤水盐运移规律进行模拟,按照淡水-微咸水-淡水顺序灌溉,每次灌后土壤湿润层积盐位置分别离土壤表层40、40、20 cm。5月土壤含盐量最低,4月土壤含盐量较3、5月偏高。3月土壤含水率最低,5月较3、4月要高。3、4、5月,研究区地下水埋深变化范围为0.7~3.5 m。研究区域土壤属于轻度盐渍化。

The project area of Sang Luoshu in Huimin was taken as the object in order to make use of water resources reasonably and to ensure the groundwater salt environment. The numerical model of soil water and salt movement were constructed using the HYDRUS software, and the numerical simulation and analysis of soil water and salt movement in this area were carried out under the condition of brackish water irrigation. The results indicated that, the HYDRUS was an appropriate model to simulate soil water and salt movement, salification zone positions were respectively at 40, 40, 20 cm from the soil surface layer after the alternate irrigation by fresh water, brackish water and fresh water; The soil salt content in May was the lowest, and it was higher in April than those in March and May. The lowest soil moisture existed in March, and it was higher in May compared with those in April and in March; Thirdly, in March, April, May, the maximum change of groundwater level ranged from 0.2 m to 2.6 m in the study region, and the study area soil belongs to mild salinization.