共查询到20条相似文献，搜索用时 113 毫秒
1.
园珠顶铜钼矿是一个新发现的矿床,设计采用露天开采方式。通过水文地质勘探,基本查明了矿区水文地质条件。矿区内地下水含水层主要为基岩裂隙含水层,按埋藏条件可分为风化裂隙潜水含水层和裂隙承压含水层两类。根据钻孔抽放水试验数据,计算含水层渗透系数,建立数学模型,采用大井法预测矿坑地下水涌水量。 相似文献
2.
我队以往采用压风机，二氧化碳结合化学洗井剂，对第四系和部分较浅的基岩钻孔进行洗井，效果较为明显。但在较深的石灰岩地层，因含水层岩溶裂隙不发育或岩粉堵塞含水层的钻孔中洗井效果甚微。为此我们在1991年先后对因后者原因造成出水量很少 相似文献
3.
裂隙倾角的富水意义 总被引：1，自引：0，他引：1
高佩义 《水文地质工程地质》1984,(5)
基岩裂隙含水层的富水性取决于补给,是以补给条件为前提的。基岩中常有这样的钻孔,开采初期出水量很大,随着时间的推移,动水位不断下降,流量逐渐减少,有的甚至干枯,这就是所谓流量衰减现象。初期流量大,说明裂隙连通性好,渗透性强,抽降条件下能使储存量迅速向钻孔汇集。流量递减,说明开采量大于补给量,储存量逐渐消耗。简单说,流量衰减现象是岩层渗 相似文献
4.
钻进过程中，冲洗液漏失，给生产带来很大困难，尤其是在高山和缺水地区更甚。现根据实际生产中一些漏失现象进行了分析，提供参考。一、关于一般基岩小裂隙含水层的漏失钻进含水层，采用泥浆作冲洗液，可保护孔壁，防止坍塌掉块，这是由于附在孔壁的泥皮起作用，因此应考虑到在一定压力差的情况下不使其破裂，以保持冲洗液的正常循环。如祁县某钻孔，孔深330米以下均是丰富的基岩含水层，岩石裂隙十分发育，根据附近同层位两个钻孔的资料分析，含水层的承压水头大约高于地面不到20米，使用泥浆护壁，钢粒钻 相似文献
5.
官地银金矿床基岩风化裂隙和断裂构造裂隙发育 ,基岩裂隙水由风化裂隙水和构造裂隙脉状水组成。脉状水与风化裂隙水相沟通 ,形成一个具有统一水位的裂隙含水系统 ,钻孔混合抽水试验也证明了基岩裂隙水这一赋存特征 相似文献
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河南嵩县北部基岩山区地下水水化学特征和环境同位素特征分析 总被引：2，自引：0，他引：2
嵩县北部基岩山区位于熊耳山脉东段南部,地下水与地表水分布不均,为研究基岩山区地下水特征和补径排关系,指导缺水山区地下水找水工作,通过现场调查、地下水采样,测定不同水体中的水化学成分及环境同位素,分析其变化特征,判明地下水的补给来源及各含水层的相互联系。水化学和环境同位素研究结果表明,大气降水是研究区地下水的主要补给来源,人工开采是其主要的排泄方式;研究区基岩地下水化学特征较复杂,松散岩类孔隙水、浅(深)层半固结层裂隙孔隙水地下水以Ca~(2+)和HCO_3~–为主,属HCO_3-Ca型水;松散岩类孔隙水、浅层半固结层裂隙孔隙水含水层之间的水力联系较为密切,基岩裂隙水通过发育的导水构造断裂与现代水连接,均具有较好的开发利用价值,而深层半固结层裂隙孔隙水参与水循环的能力较弱,开采应持慎重态度。该研究成果为缺水山区地下水的合理开采利用提供了科学依据和数据支持。 相似文献
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田永生 《水文地质工程地质》1988,(6)
笔者认为长期以来勘探地下水的大量基岩水文地质钻孔中,并未查清岩层含水性的变化规律,尽管规范要求查清含水层的层数、厚度,实际却做不到。如果把含水层比作矿层的话,没有一个人能像地质钻孔见矿那样,把含水层的层数、深度、厚度以及隔水层 相似文献
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Groundwater is the major source of water and a critical resource for socioeconomic development in semi-arid environments like the Johannesburg area. Environmental isotopes are employed in this study to characterise groundwater recharge and flow mechanisms in the bedrock aquifers of Johannesburg, which is known for polluted surface water. With the exception of boreholes near the Hartbeespoort Dam, groundwater in the study area was derived from meteoric water that has undergone some degree of evaporation before recharge, possibly via diffuse mechanisms. Boreholes that tap groundwater from the Transvaal Supergroup Formation show depletion in δ18O and δ2H values. This is attributed to diffuse recharge through weathering fractures at high elevation that are undergoing deep circulation or recharge from depleted rainfall from the high-latitude moisture sources. The influence of focused recharge from the Hartbeespoort Dam was observed in the boreholes north of the dam, possibly as a result of the north–south trending fault lines and the north-dipping fractures in the bedding planes of quartzites. This is also supported by a reservoir water budget method which indicated a mean annual net flux of 2,084,131 m3 from Hartbeespoort Dam recharging groundwater per annum. Using tritium in the dam and boreholes located at 750 m and 5400 m downstream, average groundwater flow velocity was estimated as 202 m/year. An open system was observed in shale, andesite and granitic-gneiss aquifers indicating soil CO2 as a dominant source of carbon (δ13C) in groundwater. A closed system was also observed in dolomitic aquifers indicating carbonate dissolution as the predominant source of carbon. 相似文献
12.
The cumulative storage accumulation curve (CSAC) is a tool for saturated-volume fluctuation (SVF) analysis of transient recharge
to shallow phreatic aquifers discharging only to springs. The method assumes that little underflow or phreatic evapotranspiration
occurs. The CSAC is a modified water-table hydrograph that distinguishes storage increase caused by recharge from loss due
to springflow-induced recession. Required for the analysis are water-table fluctuations at a single representative location
within the catchment of a single spring and either direct measurements or robust interpolations of springflows at different
aquifer stages. The method employs empirical manipulation of head observations, varying spring catchment area to minimize
CSAC water-level changes in late portions of long recessions. Results include volumetric estimates of recharge integrated
over individual events and instantaneous rates of recharge to the water table, at the temporal resolution of the water-level
sampling interval. The analysis may also yield physically realistic information on spring catchment and recharge focusing.
In a test case in West Virginia, USA, recharge estimates by this technique were consistent with integrated springflow time
series but greater than estimates based on potential evapotranspiration. Results give insight into dynamic recharge behavior
over time as well as an indication of recharge catchment size.
Electronic Publication 相似文献
13.
Osman A. E. Abdalla Talal Al-Hosni Abdullah Al-Rawahi Anvar Kacimov Ian Clark 《Hydrogeology Journal》2018,26(8):2561-2573
Hydrochemistry and well hydrographs are coupled to assess groundwater recharge in the regional catchment of Samail, Oman. The complex geology comprises three aquifers: limestones of the Hajar Supergroup (HSG) at the highlands of North Oman Mountains (NOM); fractured/weathered ophiolites; and Quaternary alluvium. Groundwater flows south–north from the NOM to the coast. Samples from groundwater wells and springs (38) were analyzed for isotopes and major ions. Corrected 14C dating reveals modern groundwater across the entire catchment, while 87Sr/86Sr (0.70810–0.70895) shows greater homogeneity. Groundwater in the upper catchment is depleted in 2H and 18O, indicating a high-altitude recharge source (NOM), and becomes enriched downstream, with a slope indicating an evaporation effect. The hydrographs of nested piezometers located in the upper, middle and lower catchment show different recharge responses between deep and shallower depths. Head difference in response to recharge is observed upstream, suggesting a lateral recharge mechanism, contrary to vertical recharge downstream reflected in identical recharge responses. The homogeneous 87Sr/86Sr ratio, head changes, downstream enrichment of 2H and 18O, and the presence of modern groundwater throughout the catchment suggest that groundwater recharge takes place across the entire catchment and that the three aquifers are hydraulically connected. The recharge estimated using the chloride mass balance method is in the range of 0–43% of the mean annual rainfall. 相似文献
14.
Zhou Haiyan Zhou Xun Chai Rui Yu Lan Liu Chunhui Li Liangping 《Environmental Geology》2008,53(7):1483-1489
Thermal groundwater occurs in bedrock aquifers consisting of the dolomite of the Wumishan Group of the Jixianin System and
the Cambrian carbonate in the Xiaotangshan geothermal field near the northern margin of the North China Plain, China. The
hot water in the geothermal field of basin-type discharges partly in the form of the Xiaotangshan hot spring under natural
conditions. The hot water has TDS of less than 600 mg/L and is of Na·Ca-HCO3 type. The geothermal water receives recharge from precipitation in the mountain area with elevation of about 500 m above
sea level to the north of the spring. Thermal groundwater flows slowly south and southeast through a deep circulation with
a residence time of 224 years estimated with the Ra–Rn method. The Xiaotangshan hot spring dried up in the middle of the 1980s
owing to the increasing withdrawal of the hot water in the geothermal field in the past decades. The water level of the geothermal
system still falls continually at an annual average rate of about 2 m, although water temperature changes very little, indicating
that the recharge of such a geothermal system of basin-type is limited. Over-exploitation has a dramatic impact on the geothermal
system, and reduction in exploitation and reinjection are required for the sustainable usage of the hot water. 相似文献
15.
简要叙述了柳林泉域岩溶地下水水文地质结构，明确了奥陶系上马家沟组为最主要的含水层，通过对柳林泉水及泉域内“奥灰”钻孔水质分析化验资料的主要水化学特征进行对比，确定了柳林泉南北两岸的补给来源不同，南岸来自东部子系统，北岸来自北部子系统。 相似文献
16.
There were three landforms (i.e. desert, bedrock platform and loess gully) in deep-buried coalfield of northern Ordos Basin. Water inflow of working face in desert area was 1~2 orders of magnitude larger than that in other landform areas. In order to find out the key controlling factors of the directly water filled aquifers on the roof of the coal seam, we carried out research from the aspects of topography, landform and geological sedimentation. The results showed that desert landform provides abundant recharge water for underlying aquifers because of gentle topography, large precipitation infiltration coefficient, thick and water-rich quaternary system. While bedrock platform and loess gully landform were the water sources with weak recharge capacity of underlying aquifers. The sandstone-mudstone interbedding structure formed by continental deposits resulted in the absence of regional stable aquifers in Jurassic and Cretaceous strata on the roof of coal seams. Pumping tests of boreholes showed that all strata belong to weak to medium water-rich aquifers. The groundwater level of Cretaceous aquifer decreased by 20~130 m in three mines. There was a close hydraulic relationship between shallow and deep aquifers. The Mesozoic strata belonged to fluvial deposits. Qilizhen sandstone and Zhenwudong sandstone aquifers were mainly developed on the roof of the coal seam, which were characterized by thick medium-coarse sandstone sections. The geological and sedimentary conditions of direct water-filled aquifer were similar, but the amount of borehole water, cumulative pre-drainage water and water inflow from goaf in desert geomorphic area were much larger than those in bedrock platform and loess gully geomorphic area. The water-rich of the aquifer was mainly controlled by geomorphology, and the water sources of the deep aquifers were meteoric precipitation and Quaternary aquifer. In different mines with similar Quaternary conditions in Mu Us Desert, there were also great differences in the amount of borehole water, cumulative pre-drainage water and water inflow from goafs. The difference was related to the thickness and lithology of the aquifers. It reflected that the geological sedimentary conditions of the coal seam roof were also important factors to control the water-rich of the aquifers. Topography, landform and geological sedimentation were the key factors to control the water-rich of the aquifer directly and the water inflow from the working face. 相似文献
17.
In order to improve understanding of the fate of septic tank or individual sewage disposal system (ISDS) effluent in regolith overlying fractured-rock aquifers, effluent from an ISDS in such a setting was tracked via geophysical, hydrological, and geochemical methods. Under typical precipitation conditions, the effluent entered the fractured bedrock within 5 m of the boundary of the constructed infiltration area. During a period of unusually high spring recharge, the plume migrated between 50 and 100 m within the regolith before infiltrating the fractured bedrock. The chemical signature of the effluent is similar to that required to account for the decline in water quality, suggesting a causative relationship (as estimated from mass-balance models of the surface-water chemistry near the mouth of the basin). The elevated salt content of the effluent during periods of high natural recharge to the infiltration area correlates with elevated salt concentrations in surface and groundwater at the basin scale, suggesting that some of the effluent salt load may be stored in the unsaturated zone during dry periods and flushed during periods of elevated natural recharge. 相似文献
18.
Björn S. Frengstad Kaj Lax Timo Tarvainen Øystein Jæger Börge J. Wigum 《Journal of Geochemical Exploration》2010
Twenty-two bottled mineral and spring waters from Norway, Sweden, Finland and Iceland have been analysed for 71 inorganic chemical parameters with low detection limits as a subset of a large European survey of bottled groundwater chemistry (N = 884). The Nordic bottled groundwaters comprise mainly Ca–Na–HCO3–Cl water types, but more distinct Ca–HCO3, Na HCO3 and Na–Cl water types are also offered. The distributions for most elements fall between groundwater from Fennoscandian Quaternary unconsolidated aquifers and groundwater from Norwegian crystalline bedrock boreholes. Treated tap waters have slightly lower median values for many parameters, but elements associated with plumbing have significantly higher concentrations in tap waters than in bottled waters. The small dataset is able to show that excessive fluoride and uranium contents are potential drinking water problems in Fennoscandia. Nitrate and arsenic displayed low to moderate concentrations, but the number of samples from Finland and Northern Sweden was too low to detect that elevated concentrations of arsenic occur in bedrock boreholes in some regions. The data shows clearly that water sold in plastic bottles is contaminated with antimony. Antimony is toxic and suspected to be carcinogenic, but the levels are well below the EU drinking water limit. The study does not provide any health-based arguments for buying bottled mineral and spring waters for those who are served with drinking water from public waterworks. Drinking water from crystalline bedrock aquifers should be analysed. In case of elevated concentrations of fluoride, uranium or arsenic, most bottled waters, but not all, will be better alternatives when treatment of the well water is not practicable. 相似文献
19.
The hydraulic behaviour of the karst aquifer in the Hubelj spring catchment area (SW Slovenia) was studied by using an indirect
research method based on natural tracers. The variations of natural tracers (in precipitation and in groundwater) during the
storm event made possible the separation of the Hubelj spring storm hydrograph by the three-component separation technique.
The results produced information on the aquifer recharge, storage and discharge processes, as well as on the mechanisms that
affected them. They verified the so-called epikarst hypothesis presuming that an important part of a karst aquifer recharge
reaches rapidly and intensively from the epikarst zone. It was demonstrated that epikarst water could occupy up to 50% of
the spring discharge during precipitation events. This phenomenon could have important consequences on protection and management
of the problems of karst aquifers, including engineering problems in karst areas. With this respect the results could give
way to new engineering ideas. 相似文献
20.
Widespread agricultural activity may threaten water quality in fractured bedrock aquifers having little overburden protection. A study in Canada improves the understanding of the potential impact of agriculture on water quality in bedrock aquifers, focusing on spatial and temporal variability of nitrate and bacteria. A research site was developed in and adjacent to a hay field where a gneissic aquifer is overlain by a thin veneer of unconsolidated glacial material. Ten wells were installed, hydraulically tested and completed as multilevel piezometers. Results of monthly sampling for nitrate, dissolved organic carbon, and E. coli show significant temporal and spatial variation in concentrations. Intensive 5-day sampling rounds conducted during baseflow and recharge conditions indicate that bacterial concentrations vary daily, with higher concentrations during recharge periods. The location of the impacted monitoring wells is correlated to an upgradient cattle pasture that is used periodically each summer. It is evident that periodic upgradient sources, dilution from recharge, and heterogeneous flow systems lead to varied and unpredictable contaminant concentrations. The temporal and spatial variability of contaminants in bedrock aquifers with minimal overburden must be considered for the protection of human health, as annual or even monthly groundwater monitoring may not capture unsafe concentrations. 相似文献