| 引用本文: | 侯永浩,王 楠,丁蓓蓓,等.灌溉总量限制下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
——以河北省太行山山前平原为例[J].灌溉排水学报,2022,41(12):1-9. |
| HOU Yonghao,WANG Nan,DING Beibei,et al.灌溉总量限制下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
——以河北省太行山山前平原为例[J].灌溉排水学报,2022,41(12):1-9. |
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| 摘要: |
| 【目的】在亟须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，探讨如何将有限的灌水量在冬小麦生育期内进行最优化分配，以期减少产量损失并提高地下水井灌利用效率。【方法】应用改进的SWAT模型对冬小麦生育期90 mm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、冬小麦根区纵向2 m土层深度的水分渗漏量和实际蒸散发量，基于地下水灌溉生产力优选出研究区22个子流域的最佳灌溉方案。【结果】在拔节期和抽穗期分别进行1次灌溉的“45 mm-二水”方案可实现最高的冬小麦产量，与当地农民历史灌溉情景相比，平均减产率约为20%；只在拔节期进行一次灌溉的“90 mm-一水”方案会形成较大的渗漏量，相比其他2种方案具有更好的压采效果；“30 mm-三水”方案与“45 mm-二水”方案的渗漏量相近，实际蒸散量之差在2 mm范围内，“30 mm-三水”方案下的土面蒸发量较大、“45 mm-二水”方案下的作物蒸腾量较大，后者对地下水的有效利用程度更高；为最大化地提升地下水灌溉对冬小麦增产的贡献，在河北省太行山山前平原范围内优选出适用于方案“90 mm-一水”、“45 mm-二水”和“30 mm-三水”的子流域分别有13、8和1个，分别占研究区总面积的54%、40%和6%。【结论】冬小麦生育期限水灌溉模式（灌溉定额限定为90 mm）可使研究区浅层地下水位下降速度减缓60%~75%，压采效果显著，但冬小麦产量平均下降20%~25%。不同子流域应“因地制宜”地合理分配有限的地下水资源，统筹考虑地下水涵养与作物生产，以选取最佳的灌水方案、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；地下水灌溉生产力；SWAT模型 |
| DOI：10.13522/j.cnki.ggps.2022054 |
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| Adjusting Irrigation Frequency to Ameliorate Winter Wheat Yield Reduction Due to Restricted Groundwater Extraction for Irrigation: A Case Study |
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HOU Yonghao, WANG Nan, DING Beibei, ZHANG Xueliang
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China Agricultural University, College of Land Science and Technology, Beijing 100193, China
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| Abstract: |
| 【Objective】Over-extraction of groundwater over the past decades has resulted in shallow groundwater table dropping at an alarming rate in most regions in Hebei province. Reducing groundwater extraction for wheat winter irrigation has been proposed as a remedy to reverse this trend. Quantitative understanding of wheat yield reduction due to the restricted groundwater extraction and its consequence for groundwater dynamics is essential. Taking a piedmont plain of Taihang Mountain as an example, this paper investigates how to minimize the wheat yield loss by optimizing irrigation frequency when the irrigation amount is the same. 【Method】The study was based on numerical simulation. We designed three scenarios with the irrigation amount kept the same at 90 mm, but the crop was irrigated at different frequencies. For each frequency, we simulated the winter wheat yield, variation in shallow groundwater table and soil water balance in the 0~200 cm of soil using the modified SWAT model. We divided the simulation area into 22 sub-basins, and the optimal irrigation frequency for each subbasin was calculated based on the index of crop-groundwater irrigation productivity. 【Result】 ① Irrigating the crop twice, one at jointing and one at the heading stages, at equal irrigation amount (45 mm) gave the highest winter wheat yield, with the average yield reduced approximately by 20% compared to business-as-usual irrigation method. ② Irrigating all 90mm of water at the jointing stage led to largest irrigation water leaching. ③ Increasing the irrigation frequency from two to three with the same irrigation amount in each (30 mm) did not noticeably change water leaching and evapotranspiration, but increased soil evaporation at the expense of transpiration. ④ To minimize yield reduction, 13 subbasins (approximately 54% of the studied area) should irrigate once only, 8 subbasins (approximately 40% of the studied area) should irrigate twice each with 45 mm of water, and one subbasin (approximately 6% of the studied area) should irrigate three times each with 30 mm of water. 【Conclusion】Reducing groundwater extraction for winter wheat irrigation to 90 mm could mitigate shallow groundwater table falling by 60%~75% at the price of yield reduction of 20%~25%. To minimize the yield reduction, different regions should adjust the irrigation frequencies based on its heterogeneous aquifers. Optimizing irrigation frequency should consider the trade-off effect of irrigation on groundwater conservation and crop production, as well as irrigation water use efficiency. |
| Key words: limited irrigation scheme; irrigation frequency; winter wheat; groundwater irrigation productivity; SWAT model |
