【作者】 刘君；

【导师】 陈宗宇；

【作者基本信息】 中国地质科学院 ， 地质工程， 2009， 硕士

【摘要】 气候变化和人类活动对地下水资源的影响是目前水资源可持续开发管理所关注的重要科学问题之一。而地下水补给的研究作为地下水资源评价的一个重要内容,其变化直接关系着一个地区地下水资源的可开发利用程度,其研究的重要理论和现实意义是不言而喻的。一般而言,地下水补给量是个变量,它受到多种因素的影响,主要表现为天然和人为因素两个方面。由于地下水的各项补给量是变化的,因此恢复补给历史、评估补给强度变化是比较困难的。目前估算地下水补给强度的方法主要有三种:物理方法、示踪剂方法和数值模拟。不同的方法提供的补给强度的时空范围不同,精度和适用范围也各不相同,其各有优缺点。本文主要采用示踪剂方法对地下水补给强度进行研究,并利用多种示踪剂对比验证计算结果的合理性。本文的研究目的主要是以包气带和含水层作为了解地下水补给变化的地质信息载体,提取其中所包含的水化学和同位素信息,用以估算补给强度、恢复补给历史、区分不同的补给来源、确定地下水补给机制的变化、探讨天然补给的变化特征,同时区分出天然和人工补给的量,从而为地下水资源的正确评价和合理开发利用提供理论依据。本文的研究主要侧重在以下几个方面:(1)含水层中环境示踪剂分布特征;(2)地下水年龄结构与含水层综合补给强度;(3)地下水天然补给历史与天然平均补给强度;(4)地下水补给组成区分与人类活动影响,其中关键科学问题是包气带的补给历史的恢复和地下水补给机制的识别。本研究分别从包气带和含水层两个分带的水化学和同位素信息出发,以位于滹沱河冲洪积扇中上部的石家庄地区作为典型研究区,采用环境示踪剂方法、同位素水文学方法并结合传统的水文地质学方法来对滹沱河冲洪积扇地区地下水补给强度的变化规律进行研究。通过研究主要取得以下认识:(1)本区的补给来源主要是垂向入渗补给,同时存在着一定程度的侧向补给,受地下水强烈开采影响,石家庄漏斗区附近的地下水的平均侧向渗流速度与山前平原区的平均侧向渗流速度不同,前者大于后者。(2)根据包气带示踪剂的计算结果1971年-1998年的天然平均补给强度是0.089m/a,补给强度在过去的27a间呈波动起伏的变化趋势,在1974-1977年、1985-1988年、1990-1997年间处于减小趋势,1971-1974年、1977-1985年、1988-1990年间又有所回升。通过对补给强度与降水、地下水位的变化分析可以发现补给强度的变化主要受到降水的影响,但滞后于降水的变化。(3)该区浅层地下水的年龄范围为0～36a,利用~3H—~3He法估算的该区的地下水的总的平均补给强度为0.228～0.304m/a。石家庄漏斗区地下水的平均侧向渗流速度为0.349～0.465m/d,山前平原区的平均侧向渗流速度为0.204～0.272m/d。最后利用水均衡计算结果验证了示踪剂方法得出的天然平均补给强度与综合补给强度结果的合理性。更多还原

【Abstract】 Effect of Climate Change and Human Activities on groundwater recharge is one of the important scientific issues for sustainable development and management of water resources. As a vital part of evaluation of groundwater resources, groundwater recharge has a direct influence on the extent of development and utilization of groundwater resources in an area, so its estimation has both important theoretical and realistic significances.Generally, groundwater recharge rate is not constant, it is affected by many factors, mainly natural and human factors. Because of large spatial and temporal variation, the direct measurement of groundwater recharge rate is hardly possible, so it is very difficult to reconstruct the groundwater recharge history and estimate the changes of recharge rate. Three methods, physical methods、tracer approaches and numerical modeling, are usually used to estimate groundwater recharge: These methods provide different limitations、applicability(range of spatial and temporal scales) and ratings. This paper discussed the changes of the groundwater recharge rate by using environmental tracers, and compared the results with those obtained from multiple tracers.The purpose of this paper is to estimate groundwater recharge rate、reconstruct the groundwater recharge rate、identify the different sources of recharge and recharge mechanisms、discuss the changes of natural recharge rate and distinguish the amount of natural and artificial recharge, which can provide a theoretical basis for the estimation of recharge rate and rational development and utilization of groundwater resources.This paper mainly focuses on research in the following aspects: (1) the distribution character of environmental tracers in aquifer; (2) the structure of groundwater age and total groundwater recharge rate in the aquifer; (3) the natural groundwater recharge history and average natural groundwater recharge rate; (4) distinguish the different component of groundwater recharge and the influence of human activity. The key scientific problems of these are reconstruction of groundwater recharge in unsaturated zone and distinguish for the groundwater mechanisms.Choosing ShiJiazhuang area which located in the upper part of Hutuo River alluvial-proluvial fan as a typical region, this paper discussed the changes of groundwater recharge rate in the Hutuo river alluvial-proluvial fan by environmental tracers, isotope hydrological method and conventional hydrogeological methods, on the basis of the hydrochemical and isotopic information that conserved in the unsaturated zone and aquifer. Through research, the following conclusion can be suggested:(1) In this area, the main source of groundwater recharge is vertical infiltration, and there is a certain degree of lateral flow. The average lateral recharge rate in the depression cone near ShiJiazhuang is different from the piedmont plain.(2)The average natural groundwater recharge rate calculated by environmental tracers in unsaturated zone is 0.089m/a from 1971 to 1998. The natural recharge rate shows a fluctuant trend of ups and downs in the past 27a, it tends to decrease during 1974-1977, 1985-1988, 1990-1997, while during 1971-1974, 1977-1985, 1988-1990, it has a little increase. The changes of groundwater recharge rate is mainly influenced by the changes of precipitation, and lags behind it by comparing the changes of groundwater recharge rate with precipitation and groundwater level.(3)The range of groundwater age in shallow groundwater is 0～36a. The average total groundwater recharge rate is 0.228～0.304m/a calculated by ~3H-~3He method. The average lateral Darcy velocity in the depression cone near ShiJiazhuang is 0.349～0.465m/d, and in the piedmont plain is 0.204～0.272m/d, these results are similar with the results that calculated by water balance method.更多还原