干湿田面糙率差异对灌溉模拟效果影响

Effects of roughness coefficient difference between dry and wet surface on the simulated results of irrigation modelling

田面糙率是影响畦灌水流运动过程的关键参数,其值的合理确定对灌溉模拟效果影响显著。本文基于田间实测数据,借助地面灌溉模拟模型,分析不同土质、入畦流量和坡度条件下考虑与不考虑干湿田面糙率差异对灌溉模拟效果的影响。结果表明,考虑干湿差异的模拟效果略优于不考率干湿差异的模拟效果,且通过敏感性分析得出,湿面糙率起决定性作用,干面糙率影响较小。该结果可为地面灌溉反馈控制系统中田面糙率系数的合理确定提供科学依据。

Surface roughness is a key parameter that affects water movement process in border irrigation, and rational determination of whose value has remarkable effect on irrigation simulation. Based on the observed data from typical field experiment and applied surface irrigation simulation model, this paper has an- alysed the effect on irrigation simulation under different soil texture, inflow, and slope conditions. The results show that, the simulation effects with considering the difference would be slightly better than those without consideration of that, and through sensitivity analysis, it can also be concluded that wet roughness coefficient would play a decisive role. This study intends to provide scientific basis for the rational determination of rouughness coefficient in surface irrigation feedback control system.