畦灌关口时间优化改善灌水质量分析  

Analysis on cutoff time optimization of border irrigation to improve irrigated water quality

作　　者：白美健[1] 李益农[1,2] 涂书芳 刘群昌[1,2] 

机构地区：[1]国家节水灌溉工程技术研究中心(北京),北京100048 [2]中国水利水电科学研究院水利所,北京100048

出　　处：《农业工程学报》2016年第2期105-110,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51279225);国家863计划重点项目课题(2011AA100505);国家支撑课题(2012BAD08B05)

摘　　要：灌溉关口时间是灌溉管理中的重要要素之一,合理关口时间的确定能有效改善田间灌水质量。该文在提出畦灌控制指标R和畦灌关口时间优化方法的基础上,将畦灌模拟模型与关口时间优化方法相结合,对土质、畦长、坡度、田面平整精度和入流量不同的106 176个灌溉事件进行灌溉模拟及关口时间寻优分析,提出了不同灌溉条件下畦灌关口控制模式。畦长小于70 m下R值不宜小于1,若同时坡度大于3‰且田面平整精度很好则R值不宜小于1.1;畦长大于70 m下坡度小于1‰时,R的范围为0.8-1;坡度大于1‰时,R的范围为0.75-0.95。研究结果对畦灌关口控制依据具有重要的指导意义,实际灌溉中R准确取值可参考表2给出的建议值。Irrigation cutoff time is one of the important factors of irrigation management, and the determination of optimum cutoff time can effectively improve the irrigation performances. But for different irrigation conditions, the cutoff time of irrigation is very different, and it is difficult to directly determine the cutoff time of any given irrigation event. So, the cutoff control index of basin irrigation is used to study the cutoff control modes of basin irrigation. When the irrigation water is closed before the water advance to the end of basin, cutoff control index is equal to the ratio between the water advance distance when the irrigation water is closed and the basin length. On the contrary, R is equal to the ratio between the cutoff time and the time that water advance to the end. The optimization method of optimum cutoff time for basin irrigation was presented, and the minimum infiltration depth larger than zero and storage efficiency larger than 80% were set as the objective function to optimize cutoff time. One-dimensional hydrodynamic model of basin irrigation based on the hybrid numerical method was used to simulate the basin irrigation process. Combining the irrigation model with optimization method of cutoff time, the irrigation processes of 106176 irrigation events with different soil type, basin length, basin slope, land leveling precision and inflow rate were simulated, and for the same land leveling precision, the spatial variability of surface elevation was considered. For land leveling precision of 2, 3, 4, 5 and 6 cm, 4, 12, 15, 20 and 28 groups micro-topography data were respectively generated. The corresponding optimum cutoff time for each irrigation event was obtained, the influence of the irrigation factors on the optimum cutoff time was discussed, and the irrigation cutoff control modes were proposed. The irrigation data of typical fields were used to validate the rationality of the proposed cutoff control modes by comparing the irrigation performances under different cutoff time. Results

关 键 词：灌溉 调控 模型 畦灌控制 关口控制指标 灌溉模拟 最优关口时间 灌水质量 

分 类 号：S275.3[农业科学—农业水土工程]