作物非充分灌溉制度优化的0-1规划模型建立与应用

Application of 0-1 Programming Model on Optimization of Crop Deficit Irrigation Schedule

以农田水量平衡模型及作物水分生产函数模型为基础,引入0-1变量描述在可能的灌溉期内是否进行灌溉,建立了非充分灌溉制度优化的0-1规划模型。模型利用Microsoft Excel的规划求解工具进行求解。将该模型应用于山西省潇河灌区冬小麦灌溉制度优化,结果与现有模拟-优化模型比较接近,但求解过程更为简单。结果表明研究区冬小麦灌溉的关键期是拔节末期(5月上旬);初始土壤含水率较低时,适宜灌水时间有所提前,灌溉的增产效果也更明显;冬小麦蒸散发量及相对产量均随灌水量的增加而增加,但边际产量却逐渐降低。

A 0-1 programming model was proposed to optimize the deficit irrigation schedule.It is based on the concept of field water balance and the crop water production function,and introduces a 0-1variable to describe the irrigation decision in possible irrigation periods.Microsoft Excel solver is applied for finding the solution.This model was applied in the irrigation schedule optimization of winter wheat in Xiaohe irrigation district in Shanxi Province.The result compares well with a previous developed simulation based optimization model,while the present model is much simpler in the solving procedure.Results demonstrate that the key period for winter wheat irrigation is the later jointing stage in early May.If the initial soil water content is low,the suitable irrigation time should be earlier in order to achieve higher crop yield.The evapotranspiration and relative crop yield increase with the irrigation volume,while the marginal yield decreases with the irrigation volume.