基于水量平衡原理的沟灌水流推进解析模型研究

Research on Analytic Model of Furrow Irrigation Water Movement Based on Water Balance Method

传统的基于水量平衡原理的沟灌水流推进模型研究,必须给定下渗水形状系数σz的具体值,导致模型精度受到一定影响。本文通过对下渗水形状系数σz与水流推进关系的理论分析,建立基于水量平衡原理的沟灌水流推进解析模型,确定其迭代算法,研究地表储水形状系数不同取值（介于0.70~0.80之间）对模型计算精度的影响,并结合已有的文献资料和田间试验对模型验证。研究表明：所建模型可解决沟灌过程中下渗水形状系数难以直接给定的问题,提高了模型的精度;地表储水形状系数在0.70~0.80之间的不同取值对模拟结果影响较小,且取0.75时的模拟值优于取0.70或0.80时的计算结果。验证结果表明所建立的解析模型有较为严谨的物理基础,计算方便,精度较高,具有较强的实用性。

In the traditional water movement model of the furrow irrigation based on water balance method,it is necessary to determine the value of the figure coefficient of infiltration water（σz） before simulating water flow of the furrow irrigation,which affected the precision of the model.The relationship between the figure coefficient of infiltration water and water flow under furrow irrigation was analyzed,an analytic model of furrow irrigation on the basis of water balance method was set up,and the iterative algorithm to the analytic model was determined.The influence of different σs values in 0.70～0.80 on the model compute results was studied,the model results were verified with some research results and field experimental values.The results showed that the problem of getting σz directly with difficulty was solved and the accuracy of the model was improved.It is also found that different σs values in 0.70～0.80has little influence on the model compute results and when the σs value is 0.75,it has better accuracy for the model than that when the σs value is 0.70 or 0.80.The study indicated that the analytic model has some advantages,such as simple calculation method and solution,high accuracy.