灌排系统水转化模拟模型研究

受自然与人为因素综合影响,灌区水转化过程复杂多变。以湖北漳河水库灌区为例,分别从水平和垂直方向描述典型灌排系统的水转化过程,以水量平衡原理为基础,研发灌排系统边界处置、稻作区田间多层土壤、塘坝及排水沟道之间多个水转化模拟子模块,由此构建一种客观描述灌排系统边界半封闭结构及其水平输送、垂直运动与渠-田-沟-塘水转化过程的耦合模拟模型,解决了应用流域分布式水文模型求解灌区水转化过程中面临的灌区边界不确定、分层土壤简化处理等问题。利用漳河灌区谭店灌排系统2014-2015年水平衡测试观测数据对该模型进行检验,采用拉丁超立方抽样法对模型参数进行分层抽样,并利用偏相关法分析参数敏感性。通过模型计算可得,支沟率定期和验证期模拟结果的复相关系数分别为0.83、0.70,Ens系数分别为0.81、0.68,斗沟率定期和验证期模拟结果的复相关系数分别为0.79、0.68,Ens系数分别为0.73、0.62,结果表明该模型适用于灌排系统水转化过程模拟。与SWAT模型对比,对于同一研究区域,复相关系数由0.11提高到0.73,Ens系数由-0.71提高到0.70,进一步验证了该模型的先进性,为灌排系统尺度水转化模拟和机制研究提供了新方法。

Study of water transformation simulation model of irrigation and drainage system

The process of w ater tr ansfo rmatio n in irrigation ar eas is com plicated due to the influence of natural and artificial fac2 to rs. Taking the irrigation area o f Zhanghe Reservoir in Hubei Province as a case study, w e described the water transformatio n process of a typical irrigation and drainag e system from both vertical and horizontal perspectives. Based on the principle o f water balance, we es2 tablished a simulation model that w as composed o f multiple modules for bo undary treatment and simulation of the w ater transfo rmation betw een multiple soil layers of the rice field, ponds and ditches. The model was calibrated and v erified based on the data of Tandian irri2 gation and drainage system in Zhang he district from 2014 to 2015. After sampling the model parameters using Latin hypercube, w e con2 ducted sensitivity analysis of the parameters using partial correlatio n analysis. The mo del calculat ion showed that the multiple corre2 latio n coefficients o f the simulation r esults fo r the br anch ditches in calibr ation and va lidatio n periods w ere 01 83 and 01 70 re2 spect ively, and the Ens co efficients w ere 01 81 and 01 68 respectively; the multiple co rrelatio n coefficients o f the simulation re2 sults fo r the tertiary ditches in calibratio n and v alidation perio ds w ere 01 79 and 01 68, and the Ens coefficients wer e 01 73 and 01 62, indicating that the model w as suitable for simulating the w ater tr ansfo rmatio n pro cess of irrig atio n and drainag e systems. As compared w ith the SWAT model, for t he same study a rea, the pro po sed model improv ed the mult iple correlation coefficient from 01 11 to 01 73 and the Ens coefficient from - 01 71 to 01 70, pro ving t he pro posed mo del w as superio r to the SWAT model. This study pro vided valuable info rmatio n fo r the study of w ater tr ansfo rmatio n in irrig ation and drainag e systems.