缺水条件下非充分灌溉制度预报系统的研制

以Jensen作物水分生产函数模型为基础,运用动态规划方法,建立了非充分灌溉条件下冬小麦、棉花、夏玉米的优化灌溉制度预报系统;并编制了可视化的程序界面,只要输入相关参数(土壤田间持水率、初始含水率、土壤容重、可供水量、不同阶段潜在作物蒸发蒸腾量,各阶段不同水平年的有效降雨量值和作物不同阶段的计划湿润层深度),就可得出适合于不同地区的优化灌溉制度,操作简单,具有实用性。以山西晋中和临汾地区为例验证,系统计算显示上述3种作物比传统灌溉分别节水为9%,7%和3%;在供水量不足的情况下,系统可指导如何在时间上分配水量以使减产最小,且可得知在这种灌溉方式下的具体减产量。

Development of forecasting system on deficit irrigation scheduling under water shortage

According to Jensen water-production function model of crops,the optimal irrigation schedules for winter wheat,cotton and summer maize have been established by means of dynamic programming.The visual program interface has been developed,and the suitable optimal irrigation schedule could be made for different regions as long as the related parameters(field water capacity,initial soil moisture,soil bulk density,allocated water supply,potential evapotranspiration of crops at different stages,effective precipitation at various stages in different hydrological years,and the planned wetted depth at each stage) are input.Exemplary computation was conducted for Jinzhong and Linfen areas in Shanxi,showing that the water consumption of these three foregoing crops may be saved by 9%,7% and 3% respectively,compared with the conventional irrigation method.Under the condition of water shortage,the system might supervise the allocation of water amount on the basis of time so as to minimize the reduction of output,and the quantity of yield reduction under optimal irrigation schedule could be forecasted.