基于两阶段优化配置模型的济南泉域补给区灌溉水源置换研究

Managing Groundwater Resources in Spring Recharge Area of Jinan Using the Two-stage Optimization Allocation Model

目前全球地下水能保持持续平衡的地区日趋减少,不合理农业灌溉成为很多地区地下水系统恶化的主要因素之一。济南市历城区地下水用于农业灌溉是当地地下水位下降的重要因素,对于济南泉域、白泉泉域喷涌有直接影响。针对研究区农业用水特点和水生态文明建设水源置换的要求,建立两阶段优化配置模型,将灌溉用水配置分为2个阶段,阶段一,以生态、节水和经济效益为目标,引入单位脉冲响应系数约束地下水利用量,实现区域地下水与地表水的合理配置;阶段二,以作物最大产量为目标,进行作物生育阶段水量配置和种植结构调整。结果表明,采取两阶段优化算法与用水结构调整后,可以有效减少地下水利用量,2011—2014年平均地表水与地下水用水结构由原来的3∶7调整为5.2∶4.8,较好地实现地下水源置换目标,同时地下水位计算值较实际年分别增加0.31、1.12、1.55和3.38 m,对保证泉域持续喷涌具有重要作用。

Unsustainable use of groundwater for irrigation has led to groundwater deterioration around the world. In Licheng District of Jinan, pumping groundwater for irrigation has resulted in groundwater table decline and af- fected natural flow of springs in the areas of Jinan and Baiquan. In this paper we analyzed sustainable allocation of groundwater for irrigation over the recharge areas of the springs in Jinan using two-stage optimization alloca- tion model, considering the demands for groundwater from both agriculture and ecology. The model consists of two stages. The first one sets ecology, water saving and economic profits as the objective and calculates the re- sponse coefficient of groundwater, from which we calculated the optimaluse of surface and groundwater by con- straining continuous drop of groundwater table. The second one is to maximize crop yields by readjusting the planting area of each crop and optimally allocate the amount of water calculated from Stage 1 to different grow- ing stages of the crops. We found that implementing the results calculated from the model could reduce groundwa- ter use. In particular, change the ratio of annual use of surface water to the use of groundwater from 3 ： 7 in 2011--2014 to 5.2：4.8 could rebound the groundwater table by 0.31, 1.12, 1.55 and 3.38 m respectively from 2011 to 2014, sufficient to keep the springsin Jinan flow naturally.