中文摘要：

以河北省石津灌区为研究对象，以2007--2009年两季冬小麦生育期为研究时段，基于Hydrus-1D和Modflow模型模拟分析了井渠结合灌溉模式下冬小麦的净入流量水分生产率和净灌溉水分生产率的尺度效应（作物、田间、分干、干渠和灌区尺度）。结果表明：①从作物尺度到灌区尺度，损失水量越来越多，使得净人流量水分生产率和净灌溉水分生产率分别减少了9．49％和16．59％；②由于研究区地下水埋深较大，冬小麦生育期内渗漏补给地下水库的重复利用水量很小，而净灌溉水分生产率因为考虑了这一小部分重复利用水量，比传统的灌溉水分生产率有了小幅提升；③在多年时间尺度上，由于渗漏水量能够全部进入地下水库被重复利用，净人流量水分生产率随尺度增大而增大，而不同空间尺度的净灌溉水分生产率也比冬小麦生育期时间尺度上提高37％～65％。

英文摘要：

： The objective of this study is to investigate the scale effect of net inflow water productivity and net irrigation water productivity in the winter wheat production in well-canal combined irrigation areas. To achieve this goal, the 2007--2009 growing season data of winter wheat from the Shijing Irrigation District are collected. The Hydrus-1D soft- ware package and the USGS MODFLOW model （Modular Three dimensional Finite-difference Ground-water Flow Model） are applied to calculate the water budgets across different spatial scales including the crop, the field, the sub- main canal, the main canal and the irrigation system. The results show that （~） from the crop scale to the irrigation system scale, the net inflow water productivity and net irrigation water productivity will be reduced by 9.49% and 16.59% respectively due to the increase in water loss; （~） the groundwater depth is so large that too little percolation could recharge the groundwater system for water reuse during the growing season of winter wheat. Thus, the net irriga- tion water productivity has a marginal advantage in water reusing over the traditional irrigation water productivity; （~） on a multi-year time scale, all the percolation could recharge the groundwater for water reuse, and the net inflow water productivity increases with spatial scales. Meanwhile, the net irrigation water productivities for different spatial scales could be improved between 37% and 65% on the basis of those at the winter wheat time scale.