农业限水灌溉对地下水恢复的影响研究——以河北省石家庄平原区为例

Groundwater Recovery after Restricting Groundwater Extraction for Irrigation:Taking Shijiazhuang Plain in Hebei Province as an Example

【目的】探究农业限水灌溉对地下水位和水量的恢复效果。【方法】采用GMS软件建立河北省石家庄平原区地下水模型,选取冬小麦减产率低于20%时,石家庄平原各行政区在不同降水水平下优化得到的限水灌溉组合作为限水灌溉方案,在规划压采的基础上,对所选定的限水灌溉方案进行模拟预测。【结果】与现状开采和规划压采情景相比,限水灌溉措施实施后,绝大部分行政区浅层地下水平均水位开始上升,区域浅层地下水位年均上升0.17 m/a,但深层地下水位依然呈下降趋势;平原区地下水整体由负均衡转变为正均衡,2019—2028年,浅层和深层含水层总储变量为1×10^(8)m^(3)/a;相比只采用单一规划压采措施,添加了限水灌溉措施后,储变量恢复率提高了约2.1倍,浅层地下水平均水位恢复率提高了2倍。【结论】限水灌溉对于地下水恢复效果显著,研究结果可为实现农业水资源可持续利用提供参考。

【Objective】Pumping groundwater for irrigation over the past 40 years in most regions in northern China has resulted in groundwater table falling.To alleviate the continued deterioration of groundwater-induced ecosystems,most regions have started to reduce groundwater extraction for irrigation by slightly compromising some crop yields.The purpose of this paper is to analyze its efficacy.【Method】Our analysis was based on Shijiazhuang plain in Hebei province.We established a groundwater flow model using the GMS.The schemes for groundwater-limited irrigation of winter wheat,with the associated yield reduction not dropping by more than 20%,were optimized by the simulation model under different precipitations.Meanwhile,the selected schemes for groundwater-limited irrigation were also simulated and predicted.【Result】The average shallow groundwater table in most regions begins to rise after the groundwater-limited irrigation was implemented,and the average annual rise in regional shallow groundwater table is 0.17 m.However,the table of deep groundwater continued to drop.In addition,the groundwater storage in the region has changed from decrease to increase,with the total storage in the shallow and deep aquifers increasing from 2019 to 2028 at a rate of 1×10^(8)m^(3)/a.The groundwater storage and average shallow groundwater table are increased by 2.1 and 2 times respectively after implementing the limited-groundwater irrigation,compared to simply reducing groundwater exploitation.【Conclusion】Liming groundwater-irrigation is effective for groundwater recovery;our results provide a baseline for sustainable utilization of groundwater for agricultural production.