榆溪河上游河流与地下水转化关系研究

发布时间：2018-01-28 04:24

本文关键词： 河流与地下水相互作用热运移温度示踪数值模拟榆溪河　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：水温能够表征地下水的活动,作为地下水循环的一种示踪剂,目前主要应用于河水与地下水循环及工程地下水渗漏探测两个方面。在小范围区域内,地下水温度短期内主要受补给水源温度和人类活动的影响。在榆溪河上游所选的5个试验点,均未受到人类活动的影响,因此,本次野外试验测得的温度数据主要受到河水温度和地下水温度的影响。温度数据分析结果表明,地下水温度随埋深变化,埋深越小,受到河水温度的影响越大,埋深越大,受河水温度的影响越小;在河水与地下水相互作用达到稳定时,1、2号点的稳定温度与河水温度接近,推断为河水补给地下水;3、4、5号点稳定温度与地下水温度接近,温度较高,推断为地下水补给河水。同时根据水位计所测得的测压管水头分析结果,1、2号点均由上往下水头依次减小,确定该两个试验点为河水补给地下水;3、4、5号点均由上往下水头依次增大,确定该三个试验点为地下水补给河水。应用SEAWAT软件分别模拟河流与地下水在不同水力坡度和不同渗透系数条件下对温度变化的影响,详细地了解了在不同条件下温度随时间、埋深的变化规律。根据模拟结果,在河水温度、地下水温度相同的情况下,不论渗透系数相同、水头差不同的条件下,还是水头差相同、渗透系数不同的条件下,温度剖面曲线都随时间逐渐向温度高的方向变化,并且温度变化幅度随埋深的增大逐渐减小。水头差或渗透系数越大,均使河水与地下水的交换量越大,对模型层影响的范围越大,温度变化越快;反之,则对模型层影响的范围越小,温度变化越慢。在水头差和渗透系数相同,但补排关系不同时,模型中水流模型达到稳定状态时,水量交换量相同。冬天,河水温度比较低,地下水温度较高,比较稳定,河水补给地下水时,整体温度会偏低,与河水温度接近;而地下水补给河水时,整体温度会偏高,与地下水温度接近。
[Abstract]:As a tracer of groundwater circulation, water temperature is mainly used in river water and groundwater circulation and engineering groundwater leakage detection. Groundwater temperature is mainly affected by recharge water source temperature and human activities in the short term. The five test sites selected in the upper reaches of Yuxi River are not affected by human activities. The temperature data measured in this field experiment are mainly affected by the temperature of river water and groundwater. The results of temperature data analysis show that the temperature of groundwater varies with the depth of burial, the smaller the buried depth, the greater the influence of temperature of river water. The deeper the water is buried, the less it is affected by the temperature of the river. When the interaction between river water and groundwater reaches stability, the stable temperature of point 2 is close to that of river water, which is inferred to be recharge of groundwater. The steady temperature of point 3o 4 and 5 is close to the temperature of groundwater, and the temperature is high, which is deduced as recharge of groundwater water. At the same time, according to the analysis result of pressure pipe head measured by water level meter, the results of water head analysis are as follows: 1. The No. 2 points are decreased from the top to the bottom in turn, and the two test points are determined as recharge of groundwater by river water. The three points of 4 and 5 increase from the top to the bottom. The three test sites were determined as groundwater recharge river. The effects of river and groundwater on temperature change under different hydraulic slope and permeability coefficient were simulated by SEAWAT software. The variation of temperature with time and depth under different conditions is understood in detail. According to the simulation results, under the condition of the same temperature of river water and the same temperature of groundwater, no matter the permeability coefficient is the same, the difference of water head is different. When the water head difference is the same and the permeability coefficient is different, the temperature profile curves change gradually to the high temperature direction with time. The larger the water head difference or the permeability coefficient, the greater the exchange volume between the river and the groundwater, the larger the range of influence on the model layer, the faster the temperature change. On the other hand, the smaller the influence range on the model layer, the slower the temperature change. When the water head difference and permeability coefficient are the same, but the relationship between replenishment and drainage is different, the water exchange rate is the same when the water flow model reaches the stable state in the model. The temperature of river water is relatively low, and the temperature of groundwater is relatively high and stable. When the river recharges the groundwater, the whole temperature will be lower, which is close to the temperature of the river. When the groundwater recharge the river, the whole temperature will be higher, which is close to the groundwater temperature.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P641.2;P339

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