| 引用本文: | 侯永浩,王楠,丁蓓蓓,等.灌溉总量限制条件下不同灌水频率对冬小麦产量及地下水变化的影响——以河北省太行山山前平原为例[J].灌溉排水学报,2022,(12):-. |
| HOU Yonghao,WANG Nan,DING Beibei,et al.灌溉总量限制条件下不同灌水频率对冬小麦产量及地下水变化的影响——以河北省太行山山前平原为例[J].灌溉排水学报,2022,(12):-. |
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| 摘要: |
| 【目的】在亟需推广限水灌溉模式的浅层地下水超采区—河北省太行山山前平原，定量化地探讨如何将有限的灌水量在冬小麦生育期内进行优化分配，以期减少产量损失且提高地下水井灌利用效率。【方法】应用改进的分布式水文模型SWAT对冬小麦生育期90 mm相同灌溉定额下不同灌水频率的3种限水灌溉情景进行模拟，比较各情景下的冬小麦产量、浅层地下水位变化速度、作物根系带2 m土体水分渗漏量和实际蒸散量，在此基础上基于作物地下水灌溉生产力这一指标优选出研究区22个子流域的最佳灌溉方案。【结果】①在拔节期和抽穗期分别进行一次灌溉的“45 mm-二水”方案具有相对最高的冬小麦产量，与农民历史灌溉情景相比，平均减产率约为20%；②只在拔节期进行一次灌溉的“90 mm-一水”方案会形成相对较大的渗漏量，从而比其他两种方案具有更好的压采效果；③“30 mm-三水”方案与“45 mm-二水”方案的渗漏量相近，实际蒸散量之差不超过2 mm，但就蒸散量组分的进一步分析表明，灌水三次方案下土面蒸发量较大、灌水两次方案下作物蒸腾量较大，因此后者对地下水的有效利用程度更高；④为最大化灌溉开采地下水对冬小麦增产的贡献，优选出最佳方案为“90 mm-一水”、“45 mm-二水”和“30 mm-三水”的子流域分别有13个、8个和1个，约占研究区总面积的54%、40%和6%。【结论】冬小麦生育期限水灌溉模式（灌溉定额限制为90 mm）可使得研究区浅层地下水位下降速度减缓60~75%，压采效果明显，但冬小麦产量将平均下降20~25%，不同区域应“因地制宜”地合理分配有限的水资源，从统筹考虑地下水涵养与作物生产的角度选择最佳的灌水频率方案，提高地下水井灌利用效率。 |
| 关键词: 限水灌溉；灌水频率；冬小麦；作物地下水灌溉生产力；SWAT模型 |
| DOI： |
| 分类号:S274 |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Effects of Different Irrigation Frequencies on Winter Wheat Yield and Groundwater Variations under the Limitation of a Fixed Irrigation Amount: A Simulation Study on a Piedmont Plain of Taihang Mountain in Hebei Province |
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HOU Yonghao1, WANG Nan1, DING Beibei1, ZHANG Xueliang2
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1.College of Land Science and Technology, China Agricultural University, Beijing;2.China Agricultural University
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| Abstract: |
| 【Objective】Quantitatively estimating the effects of limited irrigation amount during winter wheat growth period in a shallow groundwater overexploited region ─ a piedmont plain of Taihang Mountain in Hebei Province is very important. To solve the dilemma between water and food in this region, it is curial to explore an optimized water distribution scheme that could reduce yield loss and improve the efficiency of groundwater well irrigation.【Method】We designed three scenarios with the same irrigation quota of 90 mm but applying different irrigation frequencies, and simulated the winter wheat yield, variation rate of shallow groundwater table, and water balance in the soil profile (2 m deep) using a modified SWAT model. Based on the index of crop groundwater irrigation productivity, the optimized irrigation scheme of the 22 subbasins in the study area was selected. 【Result】①The scheme by applying two rounds of irrigation corresponding to the jointing and heading stages with the norm of 45 mm (i.e., “45 mm-twice” scheme) had the relatively highest winter wheat yield, with an average yield reduction of approximately 20% compared with the farmers’ historical irrigation schedule. ②The scheme by applying one round of irrigation at the jointing stage with the norm of 90 mm (i.e., “90 mm-once” scheme) would cause a relatively large percolation, so it has a better effect on groundwater conservation than the other two schemes; ③The percolation and actual evapotranspiration of the scheme by applying three rounds of irrigation with the norm of 30 mm (i.e., “30 mm-three times” scheme) was similar to that of the “45 mm-twice”scheme, but the soil evaporation is higher under the “30 mm-three times” scheme, while the crop transpiration is lower. Thus, the utilization efficiency of groundwater as irrigation source was higher under the “45 mm-twice” scheme. ④In order to maximize the contribution of well irrigation to increasing winter wheat yield, 13 subbasins (~54% of the study area) should applied the “90 mm-once” scheme, 8 subbasins (~40% of the study area) should applied the “45 mm-twice” scheme, and the “30 mm-three times” scheme was recommended for only one subbasin (~6% of the study area).【Conclusion】The limited irrigation scheme for winter wheat (limiting the irrigation quota to 90 mm) could mitigate the declining rate of the shallow groundwater table by 60-75%, but the winter wheat yield would decrease by 20-25% at the same time. Different regions should reasonably allocate the limited water resources according to the heterogeneous underlying surface. The optimized scheme with varied irrigation frequency should be selected with the consideration of the trade-off between groundwater conservation and crop production, to improve the efficiency of well irrigation in the study area. |
| Key words: limited irrigation scheme; irrigation frequency; winter wheat; crop groundwater irrigation productivity; SWAT model |
