摘要
因精准滴灌农田土壤水分运动、再分布和时空稳定性有别于传统地面灌溉农田,造成排水过程和排水量也不相同,为了准确模拟精准滴灌农田排水过程,在监测土壤墒情指导滴灌灌溉条件下,根据农田土壤水分的分布特征,利用有限差分法建立基于Richards方程的精准滴灌农田排水过程系统模型,并通过滴灌农田排水过程田间观测,对系统模型进行识别验证。结果表明:在灌溉周期内,农田各点潜水水位随时间逐渐趋于稳定,潜水水位模拟值与实测值的绝对误差在-13~21 mm范围内,潜水水位模拟值与实测值吻合效果较好;在降雨后农田排水过程的模拟中,NO101、NO501和NO505观测孔潜水水位模拟值与实测值的绝对误差分别为-27~47 mm、-27^-76 mm和-27^-79 mm,潜水水位模拟值与实测值在时间和空间上变化趋势一致,两者差异较小,吻合较好;系统模型能较为真实地反映精准滴灌农田的排水过程,可为大面积应用滴灌技术的现代灌区排水系统规划设计和改造以及灌排信息化管理提供参考依据。
Soil moisture’s movement,redistribution and spatial-temporal stability under the precision drip irrigation are different from the traditional ground irrigation,and the drainage process and displacement are also different.In order to simulate the farmland drainage process under the precision drip irrigation accurately,this paper sets up a mathematic model based on the Richards equation and the finite difference method according to the distribution characteristics of soil moisture.Then the model was identified and verified through field observation of farmland drainage process under drip irrigation.The results showed that the groundwater level of the farmland gradually becomes steady as time goes on in the irrigation cycle without rainfall,with an absolute errors range in-13~21 mm between the simulated and measured values.In the simulation of farmland drainage process after rainfall,the absolute errors between the simulated and measured values of the NO101,NO501 and NO505 observation holes are-27~47 mm,-27^-76 mm and-27^-79 mm,respectively.The trend of the simulated values agreed well with the measured values in time and space.The model can reflect the drainage process of farmland under the precision drip irrigation well,and can provide reference for information management of large irrigated area and design of drainage system under the precision drip irrigation.
作者
麦荣幸
康跃虎
裴亮
李晓彬
MAI Rongxing;KANG Yaohu;PEI Liang;LI Xiaobin(Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,Chinese Academic of Sciences,Beijing 100101,China;University of Chinese Academic of Sciences,Beijing 100049,China)
出处
《水资源与水工程学报》
CSCD
2019年第5期247-254,共8页
Journal of Water Resources and Water Engineering
基金
国家重点研发计划课题(2016YFC0501304)
