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61.
62.
The presence of pathogenic bacteria in water, along with the factors that act upon them, constitutes a field that has been little investigated in natural environments. It is clear, however, that these pathogens do have a significant effect on the quality of drinking water. Selected bacteria such as Salmonella, Campylobacter, Yersinia, and Listeria were searched for in groundwaters of mainly mountainous regions. Waters of one or two brooks in the catchment area of each spring were also analysed. Our results show that Campylo bacter and Listeria are frequent in all of these waters, even when land use in the catchment area is extensive (mountain pastures). Salmonella, on the other hand, was never found. Factors influencing the presence of Campylobacter, Yersinia, and Listeria were tested using Spearman rank correlations. The results suggest that the presence in water of some species of these bacteria (C. jejuni, L. monocytogenes 4b, and L. ivanovii) is related to a contaminant input, i.e. to the presence of cattle in the catchment area. For other species (C. coli, L. monocytogenes 1/2a, and Yersinia enterocolitica), however, one is forced to admit that no such connection between the presence of these species and that of an identified, potential contaminant input exists. We are therefore obliged to conclude either that these bacteria multiply in a natural way in the environment, or that they are able to survive in it for a long time. Finally, the present study shows that pathogenic bacteria are not always accompanied by indicators of faecal contamination (Escherichia coli, entero cocci); for this reason, they could potentially pose a risk to public health.  相似文献   
63.
Dubravsky Massif菱镁矿体的开采产生了部分局限在石炭纪低裂缝渗透变质岩中的喀斯特型裂缝含水层。大量的开矿过程对含水层中的地下水循环和化学成分都造成了可观的变化。本文研究了在这种复杂条件下地下水化学成分变化成因模型。根据化学配位模型,计算出所选矿物的饱和指数,从而指示所有喀斯特裂缝含水层饱和带中的地下水对菱镁矿、白云石、方解石的过饱和度和石膏的不饱和度。假设地下水未受人类活动的污染,而白云石中黄铁矿的氧化对成矿影响甚微,则水化学数据的统计描述代表了含水层中的水文地球化学背景。矿山中矿石焙烧释放的富氮气体凝聚产生的醋酸,能促进菱镁矿和白云石的溶解。这样产生的地下水相对背景值来说则富集NO3,Mg,和TIC。因此,由于地下开矿,岩溶作用估计将是原来的1.5倍。尽管有污染,这些所测参数并没有超过斯洛伐克卫生保健部颁发的No.29/2002 Z.z.饮用水标准临界值。因此采矿后含水层的开采也是可行的。  相似文献   
64.
洪云良 《地震研究》1990,13(2):189-195
下关塘子铺温泉自1970年开展水氡观测以来,水氡的前兆异常特征较为明显,对应过多次强烈地震,也成功的预报过一些地震。通过18年的观测实践,证明下关塘子铺温泉是地震观测工作中的一个灵敏点。 为探讨其灵敏原因,近年来围绕温泉、沿西洱河断层普查了一批水点,其中有4个温泉、2个冷泉、地表水两处。测定了水氡、水温、常规水质及溶解气体。企图从水文地球化学特征入手,初步探讨温泉水氡的机理,并进而探讨水氡前兆灵敏性的原因。  相似文献   
65.
我国水文地质学的展望   总被引:1,自引:0,他引:1  
当前我国水文地质学的发展,必须解决和国民经济建设紧密相关的一些问题,才能使水文地质学带有我国的特色并发育成长。以下问题是急需解决的,即供水、矿山排水,水化学、环境水文地质和实验工作中的一些难题、只有解决当前生产中存在的问题,水文地质学才能在我国成长起来。  相似文献   
66.
It is customary in Hong Kong to assume that the hydraulic conductivity of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered. Such a hydraulic conductivity pattern can only lead to an unconfined aquifer. This paper presents a case study in the regions in and around the Mid-Levels area in Hong Kong regarding a possible relatively high hydraulic conductivity (K) zone and confined groundwater along the rockhead. The Mid-Levels area is located at the lower part of the north-facing slopes of Victoria Peak on Hong Kong Island and is prone to landslides. Although this site has a long history of geotechnical studies because of extensive urban development along the coast and public concern on slope stability, hydrogeology of the site remains poorly understood. This paper reexamined the hydraulic conductivity data in 7 boreholes conducted in the 1970s and found that 4 of them indicate an increase in K at the rockhead. Groundwater conditions revealed by tunnel construction at the coast suggest that K close to the rockhead is about 10 times greater than above rockhead. A careful analysis of storm response of a piezometer group with tips in different depths indicates that there was an upward flow from the bedrock to the colluvium. A field study of two overflow standpipes conducted by the authors showed that the water level can be 0.64 and 3.73 m above the ground surface, which illustrates that the deep groundwater is significantly artesian. A search of the archived site investigation reports from the government and private companies has led to an identification of about 24 sites with overflow boreholes, which suggests that overflow phenomenon is quite common in the study area. The paper then concludes that in the study area there is a relatively high K zone along the rockhead and the groundwater in the zone is confined. It is recommended that geotechnical engineers should carry out a more careful field study on an overflow borehole because such a borehole indicates a confined groundwater condition important for slope stability study and foundation design.  相似文献   
67.
《China Geology》2018,1(3):435-449
Focusing on the Yangtze River economic zone, the previous geological researches are systematically summarized, resources and environment conditions and major geological problems which are needing to be concerned in land planning and construction are studied. The results show that the resource conditions of cultivated land, shale gas, geotherm, lithium and so on are superior in the Yangtze River economic zone, and the resources and environment conditions are conducive to develop the modern agriculture, clean energy industry and strategic emerging industries. 3×1013 m2 farmlands without heavy metal pollution are concentrated; there are three national level shale gas exploration and development bases with explored reserves of 5.441×1011 m3; geothermal availability is 2.4×109 t of standard coal each year, equivalent to 19% of the amount of coal in 2014; Asia’s largest energy lithium metal ore deposit is found. In some parts of Yangtze River economic zone, there are some major geological problems such as active faults, karst collapse, ground subsidence, landslide-collapse-debris flow, affecting the river-crossing channels, high-speed railway, urban agglomeration and green ecological corridor planning and construction. Those problems should be concerned, and the relevant suggestions and countermeasures are put forward. Meanwhile, the ideas to further support the development of the Yangtze River economic zone are put forward.  相似文献   
68.
该文分析了金阳煤矿矿井水文地质特征及充水因素,认为该矿井开采2,3煤层的直接充水水源为山西组3煤层顶板砂岩孔隙裂隙含水层。通过分析研究井下多年水文观测数据和水文地质钻孔分层抽水试验获取的基础数据,采用“比拟法”对矿井涌水量进行了预算,确定出矿井的正常涌水量和最大涌水量,为矿井今后生产提供了科学依据,也为同类研究提供了实例。  相似文献   
69.
《China Geology》2023,6(2):216-227
Yanhu Lake basin (YHB) is a typical alpine lake on the northeastern Tibetan Plateau (TP). Its continuous expansion in recent years poses serious threats to downstream major projects. As a result, studies of the mechanisms underlying lake expansion are urgently needed. The elasticity method within the Budyko framework was used to calculate the water balance in the Yanhu Lake basin (YHB) and the neighboring Tuotuo River basin (TRB). Results show intensification of hydrological cycles and positive trends in the lake area, river runoff, precipitation, and potential evapotranspiration. Lake expansion was significant between 2001 and 2020 and accelerated between 2015 and 2020. Precipitation increase was the key factor underlying the hydrological changes, followed by glacier meltwater and groundwater. The overflow of Yanhu Lake was inevitable because it was connected to three other lakes and the water balance of all four lakes was positive. The high salinity lake water diverted downstream will greatly impact the water quality of the source area of the Yangtze River and the stability of the permafrost base of the traffic corridor.©2023 China Geology Editorial Office.  相似文献   
70.
《China Geology》2020,3(1):173-181
The Beijing-Tianjin-Hebei region boasts rich geothermal resources and new achievements have been made in the exploration and development of geothermal resources in this region based on previous regional investigation. In detail, geothermal reservoirs of Gaoyuzhuang Formation of Jixian System and Changcheng System in Xiongan New Area have been recently discovered, opening up the second space of geothermal resources; the calculation method of the recoverable resources of geothermal fluid with reinjection being considered has been improved in Beijing-Tianjin-Hebei region, and uniform comprehensive assessment of shallow geothermal energy, hydrothermal geothermal resources, and hot dry rocks (HDR) geothermal resources in the whole Beijing-Tianjin-Shijiazhuang region has been completed. The scientific research base for cascade development and utilization of geothermal resources in Beijing-Tianjin-Hebei region has applied hydraulic fracturing technology to the geothermal reservoirs in Gaoyuzhuang Formation. As a result, the production capacity doubled and two-stage cascade utilization composed of geothermal power generation and geothermal heating were realized, with the first-phase installed capacity of 280 kW and the geothermal hearing is 30000 m2. In this way, a model of the exploration, development, and utilization of geothermal resources formed. Large-scale utilization has become the future trend of geothermal resource development in Beijing-Tianjin-Hebei region, and great efforts shall be made to achieve breakthroughs in reinjection technology, geothermal reservoir reconstruction technology, thermoelectric technology and underground heat exchange technology.  相似文献   
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