应用分布式水文模型优化黑龙港及运东平原农田灌溉制度Ⅱ：水分生产函数和优化灌溉制度

黑龙港及运东平原是河北省的主要农业区,同时也是华北平原的少雨中心,探讨适用于该地区冬小麦和夏玉米的水分生产函数类型,并应用于制定优化的灌溉制度,对于该区域节水农业的建设具有重要的现实意义。本文以经过参数率定与模拟验证的土壤水评价工具(SWAT)为手段,设置了1种充分灌溉处理和9种非充分灌溉情形,拟合得到冬小麦和夏玉米的水分生产函数,在此基础上,依据水分敏感系数(或指数)确定出灌溉的关键生育期,以不考虑氮磷胁迫的历史灌溉情景为基本情景,设置了3种优化灌溉方案。结果表明:在所确定的冬小麦和夏玉米灌溉的关键生育期,采用优化后的灌溉量,与基本情景相比,在保证冬小麦-夏玉米种植制度下的作物基本稳产(产量平均增加2.54%)的前提下,平均节省灌溉量23.55%,水分利用效率平均提高6.29%。总之,模拟得到的优化的灌溉制度对于该区域冬小麦-夏玉米轮作体系下的农田节水灌溉管理具有一定的参考价值。

Application of distributed hydrological model for optimizing irrigation regime in Heilong-gang and Yundong plain II. Water production function and irrigation regime optimization

Heilong-gang and Yundong plain is one of the most important agriculture region in Hebei province, it is also the low rainfall center of North China plain. The research on the water production function and optimum irrigation is of great importance. Based on the calibrated model (SWAT), this paper set up one scene of full irrigation and nine scenes of deficit irrigation, then use the ETa and yield to simulate the water production function. Based on the sensitivity index of winter wheat and summer maize, three irrigation scenarios have been set to optimize the basic scenario. The results show that in comparison with the basic scenario, 23.55% of the mean irrigation water of rotation system can be saved under the optimum irrigation regime, the mean WUE increased by 6.29%, and the yield can be kept stable (increased by 2.54%). The optimal irrigation regime offers a reference for agricultural water management of winter wheat-summer maize rotation system.