基于DRAINMOD-S模型的滨海盐碱地农田暗管排水模拟

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

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。

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 farm- lands. In this study, the basic principle and parameters of the water management model DRAINMOD-S are compre- hensively 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 coast- lines to simulate the groundwater level for different arrangements of subsurface pipe drainage. Using the calibrated pa- rameters, 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.