【作者】 郝鹏；

【导师】 郑西来；

【作者基本信息】 中国海洋大学 ， 环境工程， 2008， 硕士

【摘要】 大沽河是青岛市主要水源地之一,是青岛市生活和工农业用水的重要水源。大沽河洪水大部分发生在7-8月,历时一般为3-5d。干流洪水对地下水的渗漏补给直接影响着行洪流量和地下水补给量的大小。研究大沽河河道地下水的补排规律,对建立流量(特别是洪峰流量)与地下水渗漏量的时空关系,为大沽河流域洪水库河联合调度系统的建立提供科学的依据,也为其它季节河流域调度的研究提供借鉴。本研究对大沽河沿岸进行了气象、水文、地质等方面的调查工作,在了解和掌握国内外有关河道渗漏研究成果的基础上,采用试验分析和数值模拟相结合的方法,探讨在不同条件下河道的入渗规律及其影响因素。本文选取了大沽河沿岸上海坝和移风店的砂样作为研究对象,测定了砂样非饱和渗流特性;通过室内土柱、土槽试验和野外原位试验,模拟了河道水分的非饱和入渗;建立了不同条件下的包气带水分数值模型,对室内试验的结果进行模拟验证;利用VS2DT软件分析了水分非饱和运移时含水率和入渗通量随时间变化的特点和规律。通过上述一系列的研究,得出了一些认识和结论,主要成果如下:(1)选取了大沽河沿岸上海坝和移风店的砂样作为研究对象,通过试验获得了砂样的水分特征曲线和水力传导度,利用Van Genuchten模型进行了参数的拟合研究,并对参数拟合结果进行了分析;(2)通过土柱、土槽模拟试验,研究了在定水头入渗的条件下,不同质地、不同初始含水率的含水介质中,水分饱和-非饱和运移的规律和入渗通量随时间的变化,对孔隙中水分的迁移规律进行了探讨。通过试验数据的整理和比较,可知砂样的垂向和侧向入渗,通量随时间的变化可分为2个阶段,最初是一个较大的值,随时间迅速减小至一个较为稳定的值;然后随时间的变化趋于稳定。粗砂样在初始含水率为0.44%和9.30%时垂向稳定入渗通量约为0.003ml/(s*cm2)和0.002ml/(s*cm2)不同,细砂样在初始含水率为2.50%和9.65%时垂向稳定入渗通量约为0.002ml/(s*cm2)和0.0018ml/(s*cm2);粗砂样在初始含水率为2.60%、7.35%和13.98%时侧向稳定入渗通量约为分别约为0.002ml/(s*cm~2)、0.0011 ml/(s*cm2)、0.0008ml/(s*cm2),细砂样在初始含水率为3.20%、7.61%和16.20%时侧向稳定入渗通量约为分别约为0.0026ml/(s*cm2)、0.002ml/(s*cm2)、0.0016ml/(s*cm2)。(3)在河道上中下游选取代表性地段进行非饱和入渗试验,通过野外原位试验,测定河道上中游不同位置的入渗通量规律。三次原位试验测得于家小里稳定通量为0.028ml/(s*cm2);王璧稳定通量为0.010ml/(s*cm2);南沙梁村稳定通量为0.023ml/(s*cm2)。河道上游的砂土入渗通量比中游的大;同为上游,距离河道越近,包气带渗透性越好,入渗通量越大。(4)通过试验确定的参数、上下边界条件及初始条件等,在遵循大沽河河道特征的条件下,利用VS2DT软件建立了包气带水分运移数值模型,模拟了包气带水分的运移,验证了模型所采用的参数可以用来计算大沽河河道非饱和入渗;(5)利用VS2DT软件,对包气带水分运移的理论模型进行了初步应用研究,并模拟了初始含水率和入渗水头对垂向/侧向入渗通量大小随时间变化的影响。更多还原

【Abstract】 Daguhe River is one of the main source of water and an important sources of industrial and agricultural in Qingdao. The floods of Daguhe River usually occurred from July to August, which lasted for 3 to 5 day.The seepage of riverway to groundwater directly impacts the flux of floods and the supply of groundwater. Take a test to the seepage from Daguhe River can provide scientific basis to build a system of flow(particularly peak flow) and groundwater seepage, as well as offer a reference to other research of scheduling season river.In this study, we carried out the meteorology, hydrology, geology and other aspects of the investigation along the Daguhe River. Take both experimental study and numerical simulation to explore the rule and effect of seepage in different riverway. We made Shangshai dam and Yifengdian dam as objects, mensurated the unsaturated characteristics of samples; simulated the unsaturated infiltration with laboratory studies and field studies; established the numerical model under different conditions of vadose zone to validate the results of the laboratory tests; analyzed the characteristic and rule in unsaturated infiltration with the software VS2DT. As a result of these studies, we obtained some new understanding and conclusions as follows:(1) We selected the Shangshai dam and Yifengdian dam as studying objects,tested the curves of soil water characteristic and hydraulic conductivities of the samples, fitted the parameters and taked analyses by Van Genuchten model.(2) We studied the saturated-unsaturated infiltration and changes of flux with time under the fixed head, through the soil column and trough in the laboratory studies, discussed the rule of moisture transfer. Through the data’s collation and comparison,we know that the moisture infiltrations not only had sameness but also had their own characteristics, which were related with the way of infiltration, the river rock, the moisture content of vadose zone, the time of infiltration.The vertical flux of coarse sand were 0.003ml/(s*cm2) and 0.002ml/(s*cm2) when the intial moisture contain was 0.44% and 9.30%,and the vertical flux of fine sand were 0.002ml/(s*cm2) and 0.0018ml/(s*cm2) when the intial moisture contain was 2.50% and 9.65%. The side flux of coarse sand were 0.002ml/(s*cm2),0.0011ml/(s*cm2) and 0.0008 ml/(s*cm2), when the intial moisture contain was 2.60%,7.35% and 13.98%,and the side flux of fine sand were 0.0026ml/(s*cm2),0.002ml/(s*cm2) and 0.0016ml/(s*cm2) when the intial moisture contain was 3.20%,7.61% and 16.20%.(3) Through field studies,we determined the change of flux of seepage. According to the laboratory test results.We tested that the steady flux of Yujiaxiaoli was 0.028ml/(s*cm2), the flux of Wangbi was 0.010ml/(s*cm2) and the flux of Nashaliang was 0.023ml/(s*cm2).(4) By using the parameters, upper and lower boundary conditions, and initial conditions, which were determined by studies, we used the software VS2DT to establish a vadose zone numerical model to simulate the moisture infiltrations, got the validation that the parameters could be used to calculate the unsaturated Seepage from the Daguhe River.(5) We used the software VS2DT to take the vadose zone moisture infiltrations theoretical model in a preliminary applied research. We established a generalized model and analyzed the effects of intial moisture contain and the hand to the vertical and flux.更多还原