Hydrochemical variation in the springs water between Jerusalem–Ramallah Mountains and Jericho Fault,Palestine

The spatial and temporal changes of the composition of the groundwater from the springs along the Wadi Qilt stream running from the Jerusalem–Ramallah Mountains towards the Jericho Plain is studied during the hydrological year 2006/2007. The residence time and the intensity of recharge play an important role in controlling the chemical composition of spring water which mainly depends on distance from the main recharge area. A very important factor is the oxidation of organics derived from sewage and garbage resulting in variable dissolved CO₂ and associated HCO₃ ⁻ concentration. High CO₂ yields lower pH values and thus under-saturation with respect to calcite and dolomite. Low CO₂ concentrations result in over-saturation. Only at the beginning and at the end of the rainy season calcite saturation is achieved. The degradation of dissolved organic matter is a major source for increasing water hardness. Besides dissolution of carbonates dissolved species such as nitrate, chloride, and sulfate are leached from soil and aquifer rocks together with only small amounts of Mg. Mg not only originates from carbonates but also from Mg–Cl waters are leached from aquifer rocks. Leaching of Mg–Cl brines is particularly high at the beginning of the winter season and lowest at its end. Two zones of recharge are distinguishable. Zone 1 represented by Ein Fara and Ein Qilt is fed directly through the infiltration of meteoric water and surface runoff from the mountains along the eastern mountain slopes with little groundwater residence time and high flow rate. The second zone is near the western border of Jericho at the foothills, which is mainly fed by the under-groundwater flow from the eastern slopes with low surface infiltration rate. This zone shows higher groundwater residence time and slower flow rate than zone 1. Groundwater residence time and the flow rate within the aquifer systems are controlled by the geological structure of the aquifer, the amount of active recharge to the aquifer, and the recharge mechanism. The results of this study may be useful in increasing the efficiency of freshwater exploitation in the region. Some precautions, however, should be taken in future plans of artificial recharge of the aquifers or surface-water harvesting in the Wadi. Because of evaporation and associated groundwater deterioration, the runoff water should be artificially infiltrated in zones of Wadis with high storage capacity of aquifers. Natural infiltration along the Wadis lead to evaporation losses and less quality of groundwater.     

Environmental Isotopic Characterization of Groundwater and Surface Water in Northeast Missan Province,South Iraq

The present work studies the environmental isotopes assess groundwater characteristics of the different parts of the main aquifer in the northeast Missan Province in south of Iraq.Water samples of groundwater and surface water were collected for two dry and wet seasons during the water year of 2011–2012.The study shows that most of the groundwater in the aquifer falls above the global meteoric water line,and all the samples fall below the Mediterranean meteoric water line,indicating that these samples are a mixture of two water types.The tritium content of these samples supports this conclusion.The overall conclusion of this study indicates that there are two sources of groundwater recharge in the studied area:the ephemeral streams(Teeb and Dewerge) and major precipitation sources.According to the tritium levels at or below one tritium unit(TU) obtained from the water,supply wells are highly confined or "not vulnerable".Overall,the 3H results imply that recent recharge has taken place during the last four to five decades.In the recharge area,the high tritium content in the southern part of the Teeb area suggests that the recharge originates from rapid infiltration of surface runoff.Therefore,the groundwater resources in the study area should be protected from contamination,because it will influence the aquifer in a relatively short period of time if any contamination enters the recharge areas of the aquifer.     

Results from the Big Spring basin water quality monitoring and demonstration projects,Iowa, USA

Agricultural practices, hydrology, and water quality of the 267-km² Big Spring groundwater drainage basin in Clayton County, Iowa, have been monitored since 1981. Land use is agricultural; nitrate-nitrogen (-N) and herbicides are the resulting contaminants in groundwater and surface water. Ordovician Galena Group carbonate rocks comprise the main aquifer in the basin. Recharge to this karstic aquifer is by infiltration, augmented by sinkhole-captured runoff. Groundwater is discharged at Big Spring, where quantity and quality of the discharge are monitored. Monitoring has shown a threefold increase in groundwater nitrate-N concentrations from the 1960s to the early 1980s. The nitrate-N discharged from the basin typically is equivalent to over one-third of the nitrogen fertilizer applied, with larger losses during wetter years. Atrazine is present in groundwater all year; however, contaminant concentrations in the groundwater respond directly to recharge events, and unique chemical signatures of infiltration versus runoff recharge are detectable in the discharge from Big Spring. Education and demonstration efforts have reduced nitrogen fertilizer application rates by one-third since 1981. Relating declines in nitrate and pesticide concentrations to inputs of nitrogen fertilizer and pesticides at Big Spring is problematic. Annual recharge has varied five-fold during monitoring, overshadowing any water-quality improvements resulting from incrementally decreased inputs. Electronic Publication     

Pollution vulnerability of the Quaternary aquifer near Cairo, Egypt, as indicated by isotopes and hydrochemistry

The present study was conducted to delineate the pollution vulnerability of the Quaternary aquifer in two areas, Imbaba and Shobra El-Khima, near Cairo, Egypt. Environmental isotopes combined with hydrochemistry were used for this purpose. The groundwater in the Imbaba area (average total dissolved solids about 900 mg/L; sodium/chloride, sulfate, and bicarbonate water types) is more mineralized than groundwater in the Shobra El-Khima area (average total dissolved solids 500 mg/L; calcium and sodium/bicarbonate water type). A high nitrate content and significant mineralization in the groundwater are probably due to contamination of recharge to the aquifer by irrigation drainage, deteriorated sewage networks, and septic tanks. The deuterium and oxygen-18 compositions of the groundwater are depleted compared to Nile River water, which is the main source of aquifer recharge. This less isotopically enriched water probably represents older Nile water recharge that flooded the region before construction of the Aswan High Dam in 1963, or it is a mixture of a young water and originally deposited paleowater that was in deeper horizons at a time of cooler and more humid climate. Intensive pumping has moved the paleowater higher in the aquifer. Groundwater in the Shobra El-Khima area has higher residence time, based on the tritium concentration, than groundwater in the Imbaba area. The percentage of the isotopically depleted water equals 75% in the Shobra El-Khima and 35% in Imbaba, and the thickness of the clay cap above the aquifer is 38 m in Shobra El-Khima and 20 m in Imbaba. These factors are indicative of the rate of recharge to the aquifer and were used to evaluate the pollution vulnerability in the two areas. Electronic Publication     

云应盆地东北部含水层结构特征及地下水转化模式

云应盆地东北部属鄂北贫水地区,赋存于古近系—第四系含水层中的地下水是当地生产、生活用水的主要来源,亟需查明含水层的结构、含水层间地下水的转化关系等基本条件,为研究区内合理开发利用地下水提供依据。本研究通过野外水文地质调查、水文地质钻探工作,将研究区划分为单层含水层与双层含水层结构两个亚区（6个小区）。并通过地下水水位动态长期监测,获取了区内不同含水层的水位动态变化特征,分析各含水层之间的水力联系,建立了区域地下水转化的概念模式,即:研究区地下水以接受山前降雨入渗及风化裂隙水侧向径流补给为主,主要以水平径流的形式经古近系孔隙-裂隙含水层及第四系孔隙承压含水层往澴水方向运移,而后进入第四系孔隙潜水含水层。地下水和地表水在不同季节补排模式不同,雨季地表水（澴水）补给地下水,旱季地下水向地表水（澴水）排泄。古近系孔隙-裂隙水与上覆第四系孔隙水联系密切互为补给,共同构成具有统一水力联系的垂向多层结构的含水系统。独特的含水层结构决定了区内地下水接受降水补给的条件较差,地下水可开采资源量总体较贫乏,建议重点利用区域地表水资源,适度开发地下水资源,推进农业节水灌溉工程,实现水资源可持续利用。     

河北省滦县李家屿灰场2#副坝区灰水运动的水文地质评价

韩家哨村位于河北滦县李家屿灰场北部谷地,地势低于灰场,距离约800m。灰场运行期间,该区地下水出现水位升高及水质变差等问题。本文从水文地质条件角度,详细研究灰水的运移途径及其对该区地下水的影响。韩家哨村区域地下水系统分为上层滞水和孔隙一裂隙（溶隙）潜水含水层系统。潜水含水层系统水力传导系数为172．6～203．4m^2／d。地下水补给主要来源于韩家哨村以南坝后地形较高区域及灰水。灰水渗漏优势区韩家哨村南部宽约200m的带状区域。灰场堆灰形成新的地下水分水岭致使灰水在20副坝坝前垂直下渗进入风化带,沿白云岩裂隙（溶隙）补给潜水含水层,并向韩家哨村区域流动补给孔隙含水层,改变后的潜水部分通过民井向外排泄。     

Alluvial aquifer recharge enhanced by a natural dam: feasibility assessment based on multidisciplinary characterization (Khuzestan,Southwest Iran)

In the Kushkak Valley (Khuzestan, Southwest Iran) an anticlinal structure has partially impounded an ephemeral stream. This natural impounded area has been chosen for an artificial recharge site due to its current rate of recharge, capability to store water and favorable situation for the construction of man-made barriers to stream flow. The aquifer to be recharged is the Kushkak unconfined aquifer which consists of medium to coarse-grained alluvial deposits that overlie consolidated conglomerate rock. In this semi-arid area with infrequent relatively heavy falls of rain, alluvial aquifer recharge can be an important process that sustains shallow, over-exploited groundwater bodies. In this investigation a multidisciplinary approach including: hydrometerological studies, and a detailed hydrogeochemical survey, have been carried out. Other essential prerequisite parameters for the scheme were also taken into account to determine the suitability of this location for groundwater artificial recharge. The assessment has brought out that (1) the proposed reservoir will conserve a major part of the water being lost, (2) annual runoff of about 0.27 MCM can be injected into the aquifer through recharge from impounded water, (3) hydrochemical data from surface water and from the Kushkak aquifer water demonstrates that dilution and change in compositional trend in the groundwater proximal to the impounded alluvial bed areas would be expected based on the infiltration capacity of this site, and (4) cost–benefit ratio of the project is 1:2 and it is assumed to recover the investment within six years.     

中国西北干旱区多级洼地地下水环境同位素分布特征及指示意义

研究区位于西北干旱区,有两级储水洼地,地下水由山区侧向补给一级洼地,一级洼地通过泉水排泄地下水继而补给二级洼地,同时大气降水直接入渗、洪流间接入渗补给各储水洼地。通过氢氧同位素比例公式计算得到一级洼地大气降水占总补给量60%,其中直接补给量约占21%,山区洪流补给量约占79%,另外,山前侧向补给占40%;二级洼地降水补给量占38%,上游泉水补给量占62%。通过氚值指示,二级洼地不受现代降水影响;活塞流与全混合模型计算得到一级洼地浅层孔隙水平均年龄为32～60 a。     

Ion exchange and trace element surface complexation reactions associated with applied recharge of low-TDS water in the San Joaquin Valley,California

Stable isotope data, a dissolved gas tracer study, groundwater age dating, and geochemical modeling were used to identify and characterize the effects of introducing low-TDS recharge water in a shallow aerobic aquifer affected by a managed aquifer recharge project in California’s San Joaquin Valley. The data all consistently point to a substantial degree of mixing of recharge water from surface ponds with ambient groundwater in a number of nearby wells screened at depths above 60 m below ground surface. Groundwater age data indicate that the wells near the recharge ponds sample recently recharged water, as delineated by stable O and C isotope data as well as total dissolved solids, in addition to much older groundwater in various mixing proportions. Where the recharge water signature is present, the specific geochemical interactions between the recharge water and the aquifer material appear to include ion exchange reactions (comparative enrichment of affected groundwater with Na and K at the expense of Ca and Mg) and the desorption of oxyanion-forming trace elements (As, V, and Mo), possibly in response to the elevated pH of the recharge water.     

伊犁河支流大西沟河水与地下水转化关系研究

开展河流和地下水转换关系研究对于区域水资源合理开发利用具有重要意义。文章以大西沟河水与地下水转换关系为目标,在分析地下水动力场的基础上,通过水化学类型、溶解性总固体(TDS)、氯离子（Cl-）等水化学以及环境同位素18O、D、T等指标作为示踪剂,分析大西沟河和地下水的转换关系和转化强度。结果表明:研究区河流和地下水化学类型主要为HCO3—Ca,水化学类型空间分布特征相似;TDS和Cl-浓度表现为先增加后下降,但地下水的变化幅度大于河水。通过对大西沟河水和地下水中的水化学和环境同位素指标对比分析,发现研究区河流与地下水之间补给排泄关系具有明显的分段性;从河流出山口到下游地区,河水和地下水之间发生了三次转化关系:在山前倾斜砾质平原区以河水入渗补给地下水为主,补给量占该段潜水径流量的56%;到了细土平原区出现地下水补给河水地段,补给源为承压水越流补给潜水后的混合水体,潜水和承压水补给比例占该段河水径流量的20.4%与58.4%;风成沙漠区河水沿途渗漏补给地下水直至河流断流。本次研究结果为建立研究区水循环演化模式和水资源合理开发利用提供了理论和技术支持。     

Hydrogeological investigation of groundwater artificial recharge by treated wastewater in semi-arid regions: Korba aquifer (Cap-Bon Tunisia)

Korba aquifer is one of the most typical examples of overexploited coastal aquifer in the Mediterranean countries. In fact, from 1985, a considerable piezometric level drop, water salinization, and seawater intrusion were registered in the aquifer. In December 2008, Tunisian authorities initiated a general plan to groundwater management in order to augment groundwater resources, restore the piezometric levels, and improve water quality. The plan consists of artificial recharge of groundwater used treated wastewater through three infiltration basins. During the first 4 years (from December 2008 to December 2012), 1.41 Mm³ of treated wastewater was injected to the Korba aquifer. This study presents a hydrogeological assessment of groundwater evolution during the recharge processes. In this study, 32 piezometric and chemical surveys of 70 piezometers and observed wells are used to present hydrogeological investigation and water quality evolution of wastewater reuse through artificial recharge in Korba coastal aquifer. The piezometric evolution maps are used to specify the positive effect in groundwater level that exceeding 1.5 m in some regions. The interpretation of salinity evolution maps are used to indicate the improving of groundwater quality.     

Groundwater geochemistry of a small reservoir catchment in Central Tunisia

Due to the scarcity of water resources in semiarid sedimentary basins, hill reservoirs are often constructed to recharge groundwater and limit runoff induced water loss. The impact of such reservoirs on groundwater chemistry is investigated in the aquifers of the El Gouazine watershed, Central Tunisia. Three groundwater types are recognised, Ca–HCO₃, Na–Cl and Ca–SO₄. The strong similarity between host rock and groundwater chemistries indicates significant rock–water interaction. A flowpath, along which the chemical composition of the groundwater evolves, can be identified using the contrast in stable isotope signature between upstream and downstream groundwater. Shallow upstream groundwater is recharged by the infiltration of rainwater with the rate of recharge strongly linked to the permeability of the host lithology. Calcium and HCO₃ are supplied to an alluvial aquifer from a more rapidly recharged limestone aquifer with the concentration of Ca and HCO₃ ions decreasing by dilution. The alluvial aquifer is also enriched in Ca and SO₄ during the downstream flow of groundwater through gypsiferous materials. There is evidence of mixing between meteoric groundwater and evaporated reservoir water. Below the reservoir and partly responsible for reservoir leakage is a sandy aquifer, formed by weathering and erosion of a sandstone host which also supplies water to the alluvial aquifer.     

The hydrogeochemistry of a heavily used aquifer in the Mexican wine-producing Guadalupe Valley, Baja California

The Guadalupe Valley aquifer is the only water source for one of the most important wine industries in Mexico, and also the main public water supply for the nearby city of Ensenada. This groundwater is monitored for major ion, N-NO₃, P-PO₄, Fe, As, Se, Mo, Cd, Cu, Pb, Zn and Sb concentrations, as well as TDS, pH, dissolved oxygen and temperature. High concentrations of N-NO₃ (26 mg l⁻¹), Se (70 μg l⁻¹), Mo (18 μg l⁻¹) and Cu (4.3 μg l⁻¹) suggest that groundwater is being polluted by the use of fertilizers only in the western section of the aquifer, known as El Porvenir graben. Unlike the sites located near the main recharge area to the East of the aquifer, the water in El Porvenir graben has low tritium concentrations (<1.9 TU), indicating a pre-modern age, and thus longer water residence time. No significant variations in water quality (generally <10%) were detected throughout 2001–2002 in the aquifer, suggesting that reduced rainfall and recharge during this dry period did not significantly affect water quality. However, the wells nearest to the main recharge area in the Eastern aquifer show a slight but constant increase in TDS with time, probably as a result of the high (∼200 L S⁻¹) uninterrupted extraction of water at this specific recharge site. Relatively high As concentrations for the aquifer (10.5 μg l⁻¹) are only found near the northern limit of the basin associated with a geological fault.     

基于GMS的岩溶山区三维地下水流模式识别

以高岚河东部多条支沟切割形成的连排型河间地块为研究区,基于1∶5万岩溶水文地质调查成果,利用GIS技术和径流分割,量化岩溶含水系统顶底板高程、获取入渗补给系数及地下水径流量等数据,运用三维地下水流数值模拟及粒子追踪地下水流线的方法,得出了研究区的地下水流模式。其结果表明:研究区地下水流模式主要受区域尺度的势源和势汇控制,局部的地形起伏对地下水位的影响不明显;支沟切割较深的凉伞沟、滩淤河流域,水流驱动力大,有利于局部水流系统的发育;随着东部补给高程的增加,流程逐渐增长,多发育局部水流系统,至山脊附近多发育排泄至高岚河的中间水流系统。当研究区年降雨量由中等的1 021.1 mm降为多年最低的725.5 mm时,由东部补给区排泄至高岚河的中间水流系统增加;在此降雨强度区间,不具备发育越过河间地块的中间或区域地下水流系统。      

Groundwater age,mixing and flow rates in the vicinity of large open pit mines,Pilbara region,northwestern Australia

Determining groundwater ages from environmental tracer concentrations measured on samples obtained from open bores or long-screened intervals is fraught with difficulty because the sampled water represents a variety of ages. A multi-tracer technique (Cl, ¹⁴C, ³H, CFC-11, CFC-12, CFC-113 and SF₆) was used to decipher the groundwater ages sampled from long-screened production bores in a regional aquifer around an open pit mine in the Pilbara region of northwest Australia. The changes in tracer concentrations due to continuous dewatering over 7 years (2008–2014) were examined, and the tracer methods were compared. Tracer concentrations suggest that groundwater samples are a mixture of young and old water; the former is inferred to represent localised recharge from an adjacent creek, and the latter to be diffuse recharge. An increase in ¹⁴C activity with time in wells closest to the creek suggests that dewatering of the open pit to achieve dry mining conditions has resulted in change in flow direction, so that localised recharge from the creek now forms a larger proportion of the pumped groundwater. The recharge rate prior to development, calculated from a steady-state Cl mass balance, is 6 mm/y, and is consistent with calculations based on the ¹⁴C activity. Changes in CFC-12 concentrations with time may be related to the change in water-table position relative to the depth of the well screen.     

Groundwater level fluctuation in the Waimea Plains, New Zealand: changes in a coastal aquifer within the last 30 years

Data for the Waimea Plains, New Zealand indicate that the lower confined groundwater aquifer is hydraulically homogeneous and that shallow groundwater levels inland are affected mostly by anthropogenic processes, while those near the coast are affected more by sea level variation. Analysis of long-term data for New Zealand indicates that sea level has increased continuously, but trends are not spatially uniform. Results from non-parametric trend analysis show that rising trends for groundwater levels are predominant in the shallow aquifer both inland on the Waimea Plains and, for recent years, near the coast, while decreasing trends are evident in the underlying confined aquifer near the coast. Groundwater level change in the shallow aquifer appears to be more affected by climate change than the lower confined aquifer. Correlation analysis indicated that groundwater levels are more affected by rainfall during the rainy season than the dry season and more influenced by rainfall inland than near the coast. Groundwater level declines in the lower confined aquifer near the coast, which has its major recharge area inland in the catchment, may be substantially affected by groundwater abstraction in inland areas as well as sea level variation, but there are little evidences of seawater intrusion. Meanwhile, groundwater recharge over the catchment area has great influence on rising groundwater levels in the shallow aquifer and its recharge is estimated to be 417.8 mm/year using chloride concentrations of precipitation and groundwater.     

大清河流域平原区地下水人工补给潜力与补给方式分析

为了有效提升大清河流域平原区地下水水位,亟需在此区域开展地下水人工补给工程,并确定合理的建设位置及有效的补给方式。首先基于研究区可利用补给水源、地下水位、地表高程、地表坡度及与河道距离5个指标的分布特征,构建地下水补给潜力评价体系,采用ArcGIS空间分析功能对研究区进行了地下水人工补给潜力区划;然后在此评价体系基础上,在典型人工补给高潜力区进一步开展系列野外现场试验,探讨适宜可行的地下水人工补给方式。结果表明：研究区西北部及南部河道附近区域开展人工补给工程潜力较高,而中部、北部及西南部远离河道的区域潜力较低。高潜力区——白沟引河地段包气带及含水层渗透性良好,整体渗透系数均在5 m/d左右或更高,适宜地表补给,但河床渗透性较差,渗透系数基本在0.01~0.09 m/d间,若通过河道补给需配合清淤等措施。其中,在上游及中游沿岸适宜将河道水通过生态水渠引至修建的地表入渗池或借助天然渗坑内入渗补给,在中下游沿岸区域适宜将补给水进行严格的水处理后采用井灌方式补给,在白沟引河中下游河道适宜修建拦水坝,利用河道进行入渗补给。     

Assessment of groundwater recharge and water fluxes of the Guarani Aquifer System, Brazil

The groundwater recharge and water fluxes of the Guarani Aquifer System in the state of Sao Paulo in Brazil were assessed through a numeric model. The study area (6,748 km²) comprises Jacaré-Guaçú and Jacaré-Pepira River watersheds, tributaries of the Tietê River in the central region of the state. GIS based tools were used in the storage, processing and analysis of data. Main hydrologic phenomena were selected, leading to a groundwater conceptual model, taking into account the significant outcrops occurring in the study area. Six recharge zones were related to the geologic formation and structures of the semi-confined and phreatic aquifer. The model was calibrated against the baseflows and static water levels of the wells. The results emphasize the strong interaction of groundwater flows between watersheds and the groundwater inflow into the rivers. It has been concluded that lateral groundwater exchanges between basins, the deep discharges to the regional system, and well exploitation were not significant aquifer outflows when compared to the aquifer recharge. The results have shown that the inflows from the river into the aquifer are significant and have the utmost importance since the aquifer is potentially more vulnerable in these places.     

塔城盆地地下水氟分布特征及富集机理

塔城盆地位于新疆维吾尔自治区西北部,干旱少雨,蒸发强烈.但相对于新疆其他盆地,塔城盆地地下水水质相对较好,溶解性总固体和F-含量相对较低.为解译这种差异及盆地内高氟地下水的成因,本文在对盆地地下水样品水化学组分系统分析的基础上,结合多种水文地质调查数据,利用数理统计、离子比及主成分分析等手段,研究高氟水的成因及其分布规...     

对江苏沛县新庄铁矿区富水性规律的初步认识

江苏沛县新庄铁矿属于典型的矽卡岩类接触交代型铁矿,矿区主要富水含水层为奥陶系灰岩。分析了该矿区地下水补径排条件、矿区含水层特征及断层富水性特征,初步总结了该矿区富水性规律。认为矿坑涌水主要受上覆灰岩控制,其次受构造断层控制; 断层的涌水量受裂隙充填影响变化较大,增加了突水、透水的风险性,将直接威胁矿山的生产安全。总结该矿区富水性规律,可为国内相同类型矿山的前期勘查及后期矿床开采提供参考。