河套灌区畦灌灌水质量评价与优化

Evaluation and Optimization of Border Irrigation Performance in Hetao Irrigation District

针对河套灌区农田规格不合理问题,为探求变化环境下适宜的畦灌灌水技术要素,在不同畦田宽度下进行田间灌水试验,采用模型模拟与回归分析方法,分析了畦灌水流运动状态及灌水质量变化情况。结果表明:畦田宽度为18~23 m时灌水质量不佳,灌水效率、灌水均匀度仅分别为59.78%~77.40%和84.61%~87.02%,尽管此时储水效率为100%,但其灌水效果仍然较差;畦田宽度缩小到10~15 m时,灌水效率为70.20%~87.00%,灌水均匀度为86.77%~90.80%,灌水质量最好;当缩小畦田宽度到5 m时,灌水质量反而降低。在此基础上,结合田间实测资料,通过模型模拟、均匀试验设计以及多元回归分析相结合的方法,构建了包含灌水效率、灌水均匀度以及储水效率的单目标优化模型(Single objective optimization model),将单宽流量和灌水时间作为决策变量,采用冒泡排序法(Bubble sort method)对模型进行求解,得到畦灌适宜的单宽流量和灌水时间组合,根据示范区实际入田流量,初步确定最优畦田宽度为10.7~14.2 m。研究结果为灌区节水改造设计、水资源高效利用和农业可持续发展提供了理论依据。

Irrigation performance in fields is an important factor for the yield and water use efficiency of crops. For the unreasonable field size in Hetao Irrigation District,the flow and performance change of irrigation water in fields were analyzed by irrigation experiments in different widths of fields in order to find proper technical factors of irrigation water in fields by model simulation and regression analysis.Results showed that the irrigation performance was poor with irrigation uniformity of only 59. 78%~77. 40% and 84. 61%~ 87. 02% when the width of fields was 18 ~ 23 m. Although water storage efficiency was 100%,the irrigation performance was still poor. When the width of fields was reduced to be 10 ~ 15 m,the irrigation efficiency was 70. 20%~ 87. 00% and irrigation uniformity was 86. 77%~90. 80%,which showed best irrigation performance. When the width of fields was reduced to be 5 m,the irrigation performance was deteriorated. A single objective optimization model included irrigation efficiency and irrigation uniformity and storage efficiency combined with the field experiment data was constructed through the combination of model simulation, uniform experiment design and multiple regression analysis. Through using the single wide flow and irrigation time as decision variables and solving the model by bubble sort method,the optimal combination of technical components of border irrigation was obtained,and the appropriate width of the field was further determined based on the actual flow in the demonstration area. The results provided theoretical support for the water-saving transformation design,effective utilization of water resources and agricultural sustainable development in irrigated areas.