人工牧草需水量的模拟计算及其有效性检验

Water Requirement Calculation of Planted Fodder and Validity Examination

较高精度的模拟计算作物需水量对制定节水高效灌溉制度、灌溉排水规划和水资源合理配置至关重要。目前模拟计算作物需水量的主要方法有FAO-56双作物系数法、双涌源能量守恒模型、根系层水量平衡模型和SWAP模型。任何方法计算的作物需水量用于生产实践时,都应进行模拟结果的有效性检验。基于灌溉试验数据,应用联合国粮农组织推荐的FAO-56双作物系数法模拟计算了人工牧草———披碱草、冰草的需水量。并采用拟合相关图法、回归分析法和残差估计误差指示法对需水量模拟值进行了有效性检验。拟合相关图法给出统计相关趋势,属定性检验;回归分析法和残差估计误差指示法给出了模拟值与实测值间的拟合优度和残差估计误差的范围,属定量检验。这种定性定量相结合的方法客观的检验了需水量模拟值与实测值的一致性,经有效性检验后的需水量模拟值可用于生产实践。

Simulation precision of crop water requirement is very important for water saving irrigation system design,irrigation and drainage system planning and scientific allocation of water resources.Common approaches used for simulating crop water requirement include FAO-56 dual crop coefficient approach,two source model of conservation of energy fluxes,and water balance model of root zone,and SWAP model.Before the calculated crop water requirement is applied in practice,its validity should be examined.The crop water requirements of planted Leymus and Agropyron were simulated using the dual crop coefficient approach,and the fitting correlation diagram,regression analysis and residual errors estimation method were used to examine the validity of simulated results.The fitting correlation diagram gave statistical correlation trend,being a qualitative test method.The regression analysis and residual error estimation method indicated the goodness of fitting and the ranges of the residual estimation errors,being a quantitative test method.By integrating qualitative method with the quantitative one,the consistency between the simulated values and the observed values of crop water requirement was effectively examined.This simulated results can be applied in practice.