吉林省西部人工草地优化灌溉制度的研究

Study on Optimal Irrigation Schedule of Artificial Grassland in Western Jilin Province

节水高效的优化灌溉制度是解决农业水资源短缺的有效措施,通常所建立的灌溉制度优化模型多为具有2个决策变量的二维动态规划模型,不但求解复杂而且模型本身也存在缺陷。以吉林省松原市前郭县苜蓿人工草地非充分灌溉试验为依据,深入研究作物蒸发量与土壤水分之间的内在关系,在已建立的二维优化模型基础上,以土壤含水率为中间变量将蒸发量与灌水量联系在一起,并通过土壤水消退模型定量表述二者之间的关系,将模型改变为具有一个决策变量的动态规划问题,这样不仅求解方便,而且更为全面真实的反映土壤水分变化特征。

The optimal and efficient water-saving irrigation schedule is an effective measure to solve agricultural water shortages.Usually,the optimization model of irrigation schedule is a two-dimensional dynamic programming model with two decision variables.It is not only complex to solve,but also flawed.Based on insufficient irrigation experiment of artificial grassland of alfalfa in the Qianguo county of Jilin province,the internal relations between soil moisture and crop evapotranspiration is deeply studied.Based on the 2D optimization mode,the irrigation water quantity is contacted with the evaporation quantity by the soil water content.Moreover,the relation between them is quantitatively expressed through the soil water subsiding mode.So the 2D mode is changed into a dynamic programming model with one decision variable.It is not only convenient to solve,but also more fully reflects the variation characteristics of soil moisture.