有地表入渗的岩体渗流分析

地下水的来源主要是大气降水产生的地表入渗.许多与工程有关的岩体渗流问题,如研究域相对较大或是孤立的或半岛形山体及丘陵地带,地表入渗常为地下水唯一补给源.本文对这类岩体渗流问题分析方法及程序处理进行了讨论,并给出了工程实例.     

河北省地下水动态类型特征

根据河北省近年来地下水水位实际监测数据,结合降水量、蒸发量等影响控制因素,分析了河北省不同区域不同含水层系统内16种主要的地下水动态类型。得出河北省坝上高原及河北平原浅层地下水、岩溶泉域地下水以及基岩裂隙水补给源以降水入渗补给为主,坝上高原深层地下水、山间盆地地下水补给源以侧向补给为主,河北平原深层地下水补给源为径流、越流补给。排泄方式以开采为主,蒸发、泉群排泄次之。     

关于地下水资源评价中有关问题的探讨

从地下水径流、降水入渗及越流补给等方面，对影响地下水资源补给量的主要因素作了分析，以提高水资源计算精度，为地下水的合理开发利用提供合理的依据。     

洛阳盆地浅层地下水资源数值模拟评价

水资源的不合理利用、地下水的过渡开采导致了洛阳盆地水环境的恶化。本文结合洛阳盆地水文地质条件运用数学模型对盆地的浅层孔隙地下水资源进行模拟评价。结果表明:建立二层结构的非均质三维非稳定流数学模型,经模型识别和校正,所选参数是基本合理的,可以比较准确地模拟洛阳盆地第四系浅层地下水系统。盆地地下水补给主要为降水及灌溉入渗补给,地下水排泄主要为人工开采,占总排泄量的75.82%,因此调整和优化现状地下水开采方案,合理开采地下水资源显得尤为必要。     

西北地区水安全亟待重视

西北地区位于欧亚大陆腹地．降水稀少．蒸发强烈、具有季节温差大及风大沙多等典型的大陆性干旱气候特征。降水主要形成于山区，山区水资源补给平原区的方式有两种：一是降水或冰雪融水渗入地下形成地下水．在出山口前转化为地表水．沿河道流入平原后大量入渗又转化为地下水：二是山区降水或冰雪融水直接侧渗进入平原．形成深层地下水。从以上水资源的形成特征可     

高速公路路面渗水的环境灾害分析及其治理

本文以广东花清高速公路路面渗水问题为例,进行环境灾害分析并提出有效防治措施。通过现场水文地质试验、岩土测试以及综合环境地质调查,研究结果表明渗水由弱透水层中的潜水引起,连续降雨期间,在各种地质环境因素的共同作用下,弱透水层中的孔隙潜水面上升造成,而潜水的补给来源是分水村环形山谷中的地下水和地表水。针对其成因提出了降水盲沟的治理措施。综合考虑各种环境条件的情况下,通过降低高速公路附近的地下水水位,路面渗水现象得到了较好的控制。该事故表明在岩土工程和环境工程研究中地下水的作用应该作为一种基本环境因素进行考虑,在全球气候发生变化的大环境背景条件下,多学科结合进行环境灾害的危险性评价显得十分重要。     

尖山隧道水文地质条件分析及涌水量的预测

简述了尖山隧道的自然地理概况,对地下水的补给、径流及排泄条件等进行了说明,分别采用了大气降水入渗法、地下水径流模数法及地下水动力学法,预测了隧道洞身的正常涌水量及最大涌水量,分析了地下水动力学法更具准确性。由于地下水分布不均匀,提出施工前须做好超前地质预报工作。     

地下水垂向入渗补给机理及补给量的研究

本文从分析包气带在地下水垂向入渗补给中的作用入手，采用土水势能的原理研究了地下水垂向入渗补给的机理，在此基础上论述了水分通量法计算垂向入渗补给量的原理与步骤，并给出了应用实例。     

河南平原第四系地下水氢氧同位素特征与补给分析

河南平原第四系地下水氢氧同位素分布特征,总体上由北向南呈渐高趋势,浅、深层地下水系统水的δ18O值变化规律基本一致。平原北部系统水的δ18O值最低,并随着距离黄河越来越近而变得愈来愈小,呈现出"∨"型变化的特征。平原南部系统水的δ18O值最高,并随着距离淮河越来越近而变得愈来愈大,呈现出"∧"的变化特征。平原中部系统水的δ18O值介于该二者之间,且变化较平缓。浅层系统水主要为大气降水补给。深层系统水受开采作用,使得浅层水的越流补给已成为主要的补给来源。此外,平原北部浅层系统水,黄河侧渗补给亦是沿岸地下水的重要补给来源;而平原南部浅层系统水在接受降水补给的同时,还受到淮河的排泄。     

新旗号岭隧道涌水量分析

新旗号岭隧道为渝怀铁路二线重点工程。文章根据该隧道的水文地质和工程地质勘察,分析评价了其地质构造、地表水的发育、地下水的发育、地表水及地下水的补给等特征,结合既有线施工情况,并采用降水入渗法、地下水动力学法和比拟法分别预测了该隧道的最大涌水量,根据预测结果确定隧道全线贫富水区段及最大涌水量,进而提出了对该隧道的施工建议。     

南非西格里夸兰盆地某铁锰矿水文地质条件及矿坑涌水量预测

矿坑涌水是矿坑地下开采面临的首要问题,南非西格里夸兰盆地某铁锰矿属于未开采矿山,主要含水层为第四系松散岩类孔隙水含水层和基岩裂隙含水层。第四系松散岩类孔隙水含水层接受大气降水的入渗补给,主要排泄方式为蒸发和向基岩裂隙含水层补给。基岩裂隙含水,主要接受大气降水和第四系松散岩类孔隙水含水层补给,并沿导水性较好的构造裂隙径流,主要排泄方式为人工取水和矿坑排水。该区矿坑充水因素主要为大气降水和地下水,初步预测量矿坑正常涌水量950 m~3/d,最大涌水量2400 m~3/d,为矿区开展下一步工作提供了水文地质资料。矿山开采中应当加强监测和防范,注意附近邻区矿山采空区老空水的变化,及时评估其对矿坑涌水的影响。建立完善的防排水体系,以确保安全生产。     

云冈石窟水分来源探查工程及若干成果

水在云冈石窟文物风化损害中起关键作用。为查清水分来源,近10年来采取综合的探查工程手段在云冈石窟进行了一系列调查研究,确定了石窟山体的砂泥岩互层结构特征、岩体裂隙发育特征、山顶第四系覆盖层特征和地下水的分布特点,并在窟内凝结水的形成和山体水汽环境方面取得了新的认识。探查成果可以为石窟文物保护提供科学依据。     

云冈石窟水汽转化特征的初步研究

水汽的凝结是云冈石窟壁面水分的来源之一。研究水汽转化特征和石窟山体的水汽环境变化特征,对石窟文物的保护具有重要意义。本文阐述了水汽转化的基本原理,并针对石窟环境提出了凝结水的观测方法。通过在5号和9号洞窟布置监测系统,配合凝结水的观测,发现在夏季7、8月份云冈石窟内室存在水汽凝结的条件,单个凝结期可以持续数小时乃至数日。凝结期吸湿速率比非凝结期大0.017～0.054mm/h。窟内水汽环境变化与山体水汽环境的变化存在着相互作用。钻孔监测表明山体包气带基本处于水汽饱和状态,深部气温稳定在9～10℃之间,存在驱动空气对流的气压梯度。     

蝴蝶山隧道工程水文地质条件分析

拟建的蝴蝶山隧道设计断面大,地处华南地块的武夷—戴云隆褶带和台湾海峡沉降带,洞身穿越岩性主要为强～弱风化凝灰熔岩。隧道建设场区虽未见明显断层,但隧道洞身处约ZK253+600～+800上方左侧75m为一居民饮用水蓄水库,本隧道施工过程可能发生的最大问题是地下水渗漏和处治问题。在区域水文地条件分析基础上,采用降水入渗法和地下水动力学法进行隧道涌水量计算,ZK253+840～+878.5洞顶为碎块状强风化带,富水性较强,稳定性很差,施工中处理不当易产生突水、突泥、冒顶等不良地质现象,应引起高度重视。     

Effective storage rates analysis of groundwater reservoir with surplus local and transferred water used in Shijiazhuang City,China

Groundwater reservoir (GR) of both local precipitation and surplus water transferred from the Han River Basin is an effective method to prevent further lowering of the groundwater table. In this study, when the different volumes of infiltration water from the fuzzy mathematical analysis were input in the simulation, the rate at which the groundwater table rose ranged from 1.47 to 3.45 m/a. The effective storage rate (ESR) values of GR and the local reservoir was calculated, and ranged from 80.50 to 90.95% and from 49.66 to 80.90%, respectively. In GR, the ESR decreased as artificial recharge increased. Comparison of the ESR values between local reservoir and GR showed that if the volume of artificial recharge water available was < 7.86 × 10⁸ m³/a, then GR was a better storage method than the local reservoir. According to our results, this situation would occur 80.30% of the time.     

A case study of urban water balancing in the partly sewered city of Nablus-East (Palestine) to study wastewater pollution loads and groundwater pollution

Untreated sewage can contribute a significant proportion of urban groundwater recharge, via on-site sanitation facilities and sewer exfiltration. In the West Bank of the Palestinian Territories 94% of sewage is discharged untreated to the ground or surface waters. This has contributed to increasing nitrate concentrations in groundwater, which is the critical water source. In this case study of a drainage catchment from the city of Nablus, a water balance indicates that sewage as a source of groundwater recharge is as much as 50% of total recharge from precipitation, and nitrogen pollutant loads by area are up to 60% as much as those from agriculture. Results suggest that 22% of total wastewater flow directly infiltrates the ground via cesspits and sewer exfiltration.     

Infiltration und Grundwasserströmung in geklüftet-porösen Buntsandsteingrundwasserleitern im Osten des Thüringer Beckens

In the eastern Thuringian Basin, the low precipitation rate of 585?mm/y limits the groundwater resources in the sandstone aquifer system. The aim of this study was to develop a groundwater flow model for the region in order to forecast the impacts of different climate scenarios on the groundwater balance. Since recharge is of high relevance for the numerical model, a time series of groundwater levels were investigated to obtain the recharge input function. In the sandstone aquifer it could be shown that groundwater flow is characterised by flow in the fracture network as well as in the matrix. The largest fraction of recharge reaches the water table very quickly via the fracture network. However, both the thickness of the unsaturated zone and the low hydraulic conductivity of the sandstone matrix control the time lag of groundwater recharge. The time lag of the slow component to reach the water table is in the order of several years.     

Electrodialysis and nanofiltration of surface water for subsequent use as infiltration water

In order to achieve stable groundwater levels, an equilibrium between the use of groundwater for drinking water production and natural or artificial groundwater recharge by infiltration is needed. Local governments usually require that the composition of the water used for artificial recharge is similar to the surface water that is naturally present in the specific recharge area. In this paper, electrodialysis (ED) and nanofiltration were evaluated as possible treatment technologies for surface water from a canal in Flanders, the North of Belgium, in view of infiltration at critical places on heathlands. Both methods were evaluated on the basis of a comparison between the water composition after treatment and the composition of local surface waters. The treatment generally consists of a tuning of pH and the removal of contaminants originating from industrial and agricultural activity, e.g., nitrates and pesticides. Further evaluation of the influence of the composition of the water on the characteristics of the artificial recharge, however, was not envisaged. In a case study of water from the canal Schoten-Dessel, satisfactory concentration reductions of Cl(-), SO(4)(2-), NO(3)(-), HCO(3)(-), Na(+), Mg(2+), K(+) and Ca(2+) were obtained by ultrafiltration pretreatment followed by ED. Nanofiltration with UTC-20, N30F, Desal 51 HL, UTC-60 and Desal 5 DL membranes resulted in an insufficient removal level, especially for the monovalent ions.     

Natural organic matter (NOM) removal and structural changes in the bacterial community during artificial groundwater recharge with humic lake water

This study evaluated the removal of natural organic matter (NOM) and structural changes in the microbial community during infiltration of humic lake water at three artificial groundwater recharge (AGR) sites in Finland. The three sites were at waterworks in H?meenlinna, Jyv?skyl? and Tuusula, sites A, B and C, respectively. Site A used groundwater recharge by both basin and sprinkling infiltration, site B used only sprinkling infiltration, and site C used only basin infiltration. Reductions of total organic carbon at sites A, B and C were 91%, 84% and 74%, respectively, in the winter, and 88%, 77% and 73%, respectively, in the summer. The Finnish national recommended value of 2 mg/l for TOC was achieved at all sites and the TOC of natural groundwater at site C was much lower, at 0.6 mg/l. Large molecular fractions of NOM were removed more efficiently than the smaller ones. Total amount of DAPI-stained cells decreased during infiltration at sites A, B and C in winter by 94%, 94% and 75% and in summer by 96%, 97% and 94%, respectively. Bacterial communities in raw waters and extracted groundwaters were diverse with changes occurring during infiltration, which was shown by DNA extraction followed by PCR of 16S rRNA genes and denaturing gradient gel electrophoresis (DGGE) fingerprinting. While the natural groundwater microbial community was diverse, it was different from that of the extracted groundwater in the AGR area. Simultaneous organic carbon removal and the decrease of bacterial counts during infiltration indicated biodegradation. In addition, the changing DGGE profiles during the process of infiltration, demonstrated that changing environmental conditions were reflected by changes in bacterial community composition.