典型灌溉模式下灌溉水利用效率尺度变化模拟

Analysis of scaling variation of irrigation water use efficiency under typical irrigation regimes

为探讨灌区水分利用效率的尺度特征以及适宜的灌溉模式,以湖北漳河灌区为背景,基于改进的分布式水文模型,模拟得到"间歇"灌溉和"薄浅湿晒"灌溉模式下不同尺度水平衡要素和作物产量分布.结果表明,2种灌溉模式下的灌溉水分生产率和毛入流水分生产率在小于一临界尺度时,都随尺度增大而增大,当大于此临界尺度后,则处于平缓甚至有下降趋势."薄浅湿晒"模式比"间歇"模式节约灌溉水量19%左右,而灌溉水分生产率提高约1 kg/m3.因此对于漳河灌区,"薄浅湿晒"是一种值得推广的节水灌溉模式.

In order to investigate the scaling properties of irrigation water use efficiency （IWUE） and get a suitable water-saving irrigation regime for Zhanghe Irrigation District （ZID）, a distributed hydrological model is developed based on SWAT and subsequently to simulate hydrological processes and crop yields. The IWUE for different scales is obtained with the two simulated products under the intermittent submerged irrigation （ISI） regime end the thin-shallow-wet-dry irrigation （TSWDI） regime. It is found that the irrigation water productivity （IWP） increases with the scale being extended, while it may keep at a stable level as the scale exceeds a critical value. Comparing with the ISI regime, the TSWDI could save irrigation water about 19% with a higher level of IWP （about 1 kg/m^3 excess）. These excellent performances demonstrate that the TSWDI regime is adoptable for Zhanghe Irrigation District.