基于DRAINMOD-S模型的滨海盐碱地农田暗管排水模拟

在分析农田暗管排水饱和-非饱和土壤水、盐运移数学模型的基础上,对DRAINMOD-S模型的基本原理和参数输入要求进行了详细描述,利用典型滨海盐碱地区实测土壤、气象、作物等资料,用DRAINMOD模型对不同排水暗管布置方案的地下水埋深进行了长序列模拟,在模拟率定参数的基础上,用DRAINMOD-S模型对0~80 cm土壤层剖面含盐量进行了模拟,结果表明:模型具有良好的水文模拟性能,地下水位及土壤含盐量模拟值与实测值拟合精度较高;可用于预测盐碱地地下水埋深、土壤层剖面中盐分含量,是改良盐碱地农田暗管排水工程设计和水管理的有效工具。

Simulating subsurface pipe drainage in saline-alkali farmland along coastlines using the DRAINMOD-S model

Farmland pipe drainage is one of new engineering measures to improve saline-alkali soils. It is important to simulating farmland water and salt migration for the construction and management of a pipeline system on farmlands. In this study, the basic principle and parameters of the water management model DRAINMOD-S are comprehensively introduced on the bases of mathematically modeling flows and salt migration in saturated-unsaturated soils. The DRAINMOD-S model is used with the weather, soil and crop data collected from typical saline lands along coastlines to simulate the groundwater level for different arrangements of subsurface pipe drainage. Using the calibrated parameters, the salinity profile of 0-80 cm soil layer is simulated with the DRAINMOD-S model. The result shows that the DRAINMOD-S model performs well for hydrological simulation. Both groundwater level and salinity profile are in good agreement with observation. The DRAINMOD-S model is able to predict the groundwater depth in saline-alkali soils and the salt content in soils. The model is a useful tool for the design and management of a pipeline system on farmlands.