【作者】 王喆；

【导师】 高学平； 李振；

【作者基本信息】 天津大学 ， 水利工程， 2018， 硕士

【摘要】 为解决于桥水库水体富营养化问题,拟修建于桥水库前置库工程净化水质。该工程裁弯取直修建节制闸,抬高了上游黎河水位1m左右,回水区域可沿河道上溯约15km,同时也抬高黎河下游河道两岸地下水位,打破了原有的水源平衡,造成周边土壤条件发生变化,带来一系列生态影响。本文采用数值模拟方法对黎河下游河道及其周边区域河流—地下水系统展开研究。基于水动力河道模型HEC-RAS和三维地下水模型MODFLOW,建立河流—地下水系统双向耦合模型,采用皮卡尔迭代法调整系统水量平衡以减小流量残差。自2017年5月至2017年10月,进行多次实地考察与野外量测,获取5组不同工况下地下水位数据,用于参数的率定与模型的校验。经计算,模型模拟值与实测值相关系数均大于0.97,纳希效率系数均大于0.95,系统流量残差减小约0.6m~3/s。将模型应用于黎河下游及其周边河道—地下水系统的研究,并结合引滦输水情况及黎河流域水文条件提出8组模拟工况,得到如下结论:(1)对于黎河河道,水位抬升幅度约为1.0~0.0m,回水区域沿河道上溯约13~16km。(2)对于地下水位,自入库口至果河桥的西部区域地下水位抬升明显,最大抬升幅度均在1.0~0.9m,河道左右两岸的影响范围约为1.0~1.7km;自果河桥至王各庄桥的中部区域地下水位抬升自西向东逐渐衰减,抬升幅度在0.9~0.1m,河道左右两岸的影响范围约为0.1~1.5km不等;自王各庄桥至东梁子河桥的东部区域,周边地下水位基本无变化。同时,研究区地下水埋深一般大于2.00m,仅引滦输水期接近1.80m,故发生土壤(次生)盐渍化可能性较小,但不建议采取长期大流量引滦输水方案。(3)对于水量平衡,河流对地下水的补给量增大,而地下水对河流的排泄量减少,潜水蒸发量增加。(4)对于河流和地下水补排关系。上游河段地下水位高于河道水位,下游河段地下水位与河道水位较为接近。地下水位、河道水位均有所抬升且二者水位差减小,但整体而言地下水位依然略高于河道水位。说明河流和地下水补排关系以地下水排泄河道为主。更多还原

【Abstract】 In order to solve the problem of eutrophication in Yuqiao reservoir,a pre-reservoir project has been constructed to purify the water quality.Cutting off the corner and bending straightening,a check gate has been built.Water level raises up 1m or so,serpentine backwater area along the river back is about 15 km.The groundwater level on both sides of the river in the lower reaches of the Lihe River has been raised,which has broken the original water balance and changed the local soil conditions,resulting in a series of ecological impacts.Using numerical simulation method,a study on river-groundwater system is carried on in this paper.Based on hydrodynamic river model HEC-RAS and 3D groundwater models MODFLOW,a two-way coupling model is established.Flow residual is reduced by adjusting the water balance with application of the Picard cycle.Through field surveys and measurements from May 2017 to October 2017,5groups of measured data were obtained,which were used in the parameter calibration and model verification.The validation results manifeste that correlation coefficient of the simulated and measured value is over 0.97,Nash–Sutcliffe efficiency is over 0.95,the system flow residuals decreases by 0.6m~3/s.The coupling model was then applied into the research of river-groundwater system and then eight sets of working conditions are proposed in combination with the water supply and hydrological conditions of the Lihe River basin.The conclusions are as follows.(1)For the Lihe River,the elevation of river water level is about 1.0~0.0 m,and the backwater area is about 13~16km along the channel.(2)For the groundwater,the water level from the entrance of reservoir to the Guohe Bridge has been raised obviously,where the maximum lifting range is1.0~0.9m and the influence area of both sides of the channel is about 1.0~1.7km.The water level from the Guohe Bridge to the Wanggezhuang Bridge is gradually decreasing from west to east,where the maximum lifting range is 0.9~0.0m and the influence area is about 0.1~1.5km.There is no change in the water level from the Wanggezhuang Bridge to the Dongliangzihe Bridge.At the same time,the groundwater depth in the study area is generally greater than 2.00 m.When the water is diverted from Luanhe River to Yuqiao Reservoir,it is close to 1.80m.Therefore,soil(secondary)salinization is very unlikely.However,to take long-term flow diversion scheme is not recommended.(3)For the water balance,seepage recharge from river to groundwater has increased and discharge from groundwater to river has decreased.Besides,the diving evaporation has increased.(4)For the relationship between river and groundwater,the groundwater level is higher than the river water level in the upper reaches.And in the lower ones,the groundwater level is closer to the river water level.The river and groundwater level are both lifted and the difference of them is reduced.But overall,the groundwater level is still slightly higher than the river’s,indicating that it is still dominated by the discharge from groundwater to surface water.更多还原