基于AquaGIS模型的盈科灌区制种玉米农业用水效率分析

盈科灌区是黑河流域中游绿洲典型灌区之一,该灌区农业用水效率较低,农业用水矛盾十分突出。制种玉米是灌区主要种植作物,研究制种玉米的优化灌溉制度对实现该区域农业用水可持续发展具有十分重要的意义。利用分布式作物模型AquaGIS模型,基于盈科灌区土壤质地的空间变异性对该灌区制种玉米灌溉制度进行了优化,提出了适合灌区实际配水情况的最佳灌溉制度。通过灌溉制度优化,灌区制种玉米蒸散发量减少36~53mm,水分生产率WPET增加5%左右,灌溉水生产率WPI增加25%~48%,极大地提高了灌区农业用水效率。同时,对该灌区不同水文年灌溉制度进行优化,综合对比灌区制种玉米WPET、WPI和产量,其中丰水年灌溉3次、平水年灌溉4次、枯水年灌溉5次可以实现农业用水效率最高,为灌区高效节水灌溉提供理论指导。

Analysis of agricultural water use efficiency of seed maize in Yingke Irrigation District based on AquaGIS Model

Yingke Irrigation District (YID) is one of the typical irrigation district in the middle oasis of Heihe River Basin. With the low agricultural water use efficiency, the contradiction between the supply and requirement of agricultural water use is outstanding. The maize for seed is the main crop in YID, and it is of great significance to study the optimized irrigation system for the production of seed maize for the sustainable development of agricultural water in the region. In this paper, the irrigation system of maize for seed was optimized based on the AquaGIS model and the spatial variability of soil texture in YID, and the best irrigation system suitable for the actual condition in YID were proposed. Through the optimization of irrigation system, the evapotranspiration of maize for seed in YID reduced from 36 mm to 53 mm, the water productivity (WP_ET) increased by 5%, and the irrigation water productivity (WP_l) increased by 25%-48%, which greatly improved the agricultural water use efficiency of the irrigation area. At the same time, the irrigation system of different hydrological years in the irrigation district was optimized. Comprehensively comparing the WP_ET, WP_l and yield of maize for seed, the optimal irrigation system for different hydrological years was proposed, that is, three times for wet years, four times for normal years and five times for drought years, providing theoretical guidance for high efficiency water saving irrigation in YID.