Uncertainty Analysis of Mound Monitoring for Recharged Water from Surface Spreading Basins

This study has conceptually reviewed issues related to implementation of a groundwater mound monitoring well (GMMW) for monitoring recharged water from a surface spreading basin with emphasis on uncertain hydrogeological conditions. For this, we selected a recharge site in the City of Mesa, Ariz., that is characterized with near-surface clay lenses of low permeability. A geostatistical simulation technique was used for generating hydrogeological fields under the recharge basin, using soil boring logs and historical hydrological data. More than 50 hydrogeological fields were generated and used for modeling. Five scenarios were formulated with varying parameter values and different initial and boundary conditions, and each scenario was evaluated with the 50 hydrogeological fields generated. Results of this study indicate that travel times to the mound may vary by over one order of magnitude and the use of a GMMW will only be practical for regulatory compliance in a homogeneous system.     

紫金山露天金矿边坡地下水渗流场分析

渗流计算的目的在于求得各渗流要素,以在边坡稳定性分析、选择合理排渗或加固方案设计中起到提供基础资料的作用。采用数值计算方法更能符合和满足工程条件和需要。通过分析得到了以下结论：因地下水埋深较深,加之天然地下水流向与坡面反向,边坡靠帮后,在坡面的疏干作用下,边坡为有利于稳定的干边坡;终了计算得出的地下水位线,是根据目前资料而定的,实际地下水位线只能通过有限的工作,建立研究区内的裂隙水水文地质模型得到。     

栖霞山铅锌矿防治水体系的建设

栖霞山铅锌矿目前已开采至-725 m中段,水文地质条件较浅部有一定的变化.为了防止井下出现突水事故,矿山企业从制定防治水制度文件,加强水文地质调查研究,完善水文地质图纸台账,建立能力符合要求的排水系统等多个方面形成了一套较为完善的防治水体系.实际应用证明,该体系对查清水文地质情况,防止矿山发生突水事故发挥了重要作用.     

大兴安岭北部砂宝斯金矿水文地质特征及供水方向评价

砂宝斯金矿位于额尔古纳隆起的北东端,上黑龙江断陷盆地的边缘,共固定5条工业矿体,平均金品位1．19×10^-6,主要含水层为中侏罗统二十二站组砂岩、下寒武统额尔古纳组大理岩。通过分析矿区供水条件,指出矿区地下水贫乏、水质差,不能满足未来矿区生产、生活需要,需进行以地表水为主的供水,认为小东沟河可作为未来矿区首选供水源,开采时应注意钻孔封孔质量。     

Developing a modular hydrogeology ontology by extending the SWEET upper-level ontologies

Upper-level ontologies comprise general concepts and properties which need to be extended to include more diverse and specific domain vocabularies. We present the extension of NASA's Semantic Web for Earth and Environmental Terminology (SWEET) ontologies to include part of the hydrogeology domain. We describe a methodology that can be followed by other allied domain experts who intend to adopt the SWEET ontologies in their own discipline. We have maintained the modular design of the SWEET ontologies for maximum extensibility and reusability of our ontology in other fields, to ensure inter-disciplinary knowledge reuse, management, and discovery.The extension of the SWEET ontologies involved identification of the general SWEET concepts (classes) to serve as the super-class of the domain concepts. This was followed by establishing the special inter-relationships between domain concepts (e.g., equivalence for vadose zone and unsaturated zone), and identifying the dependent concepts such as physical properties and units, and their relationship to external concepts. Ontology editing tools such as SWOOP and Protégé were used to analyze and visualize the structure of the existing OWL files. Domain concepts were introduced either as standalone new classes or as subclasses of existing SWEET ontologies. This involved changing the relationships (properties) and/or adding new relationships based on domain theories. In places, in the Owl files, the entire structure of the existing concepts needed to be changed to represent the domain concept more meaningfully. Throughout this process, the orthogonal structure of SWEET ontologies was maintained and the consistency of the concepts was tested using the Racer reasoner. Individuals were added to the new concepts to test the modified ontologies. Our work shows that SWEET ontologies can successfully be extended and reused in any field without losing their modular or reference structure, or disrupting their URI links.     

矿井底板承压水突水特征与防治措施研究现状

在参考国内外相关文献的基础上,从煤矿水文地质、底板承压水突水特征、矿井水防治措施三个方面对国内外目前底板承压水突水特征与防治措施研究现状进行了介绍.     

Hydrogeological and isotopic survey of geothermal fields in the Buyuk Menderes graben, Turkey

The main high and low enthalpy geothermal fields in the Buyuk Menderes graben (Western Anatolia) and their reservoir temperatures are as follows: Kizildere (242 °C), Germencik (232 °C), Aydin-Ilicabasi (101 °C), Yılmazkoy (142 °C), Salavatli (171 °C), Soke (26 °C), Denizli -Pamukkale (36 °C), Karahayit (59 °C), Golemezli (101 °C) and Yenice (70 °C). The geothermal systems are controlled by active graben faults. The reservoir rocks in the geothermal fields are the limestone and conglomerate units within Neogene sediments and the marble-quartzite units within Paleozoic metamorphic formations. There are clear δ¹⁸O shifts from the Mediterranean Meteoric Water Line (MMWL) in the Kizildere, Germencik and Aydin fields, where a good relation between high temperatures and δ¹⁸O shift has also been observed, indicating deep circulation and water rock interactions. In the Pamukkale, Karahayit, Golemezli and Yenice fields and in Soke region, low temperatures, small isotope shifts, shallow circulations and mixing with shallow cold water have been noted.     

Field Performance of a Compacted Clay Landfill Final Cover at a Humid Site

A study was conducted in southern Georgia, USA, to evaluate how the hydraulic properties of the compacted clay barrier layer in a final landfill cover changed over a 4-year service life. The cover was part of a test section constructed in a large drainage lysimeter that allowed continuous monitoring of the water balance. Patterns in the drainage (i.e., flow from the bottom of the cover) record suggest that preferential flow paths developed in the clay barrier soon after construction, apparently in response to desiccation cracking. After four years, the clay barrier was excavated and examined for changes in soil structure and hydraulic conductivity. Tests were conducted in situ with a sealed double-ring infiltrometer and two-stage borehole permeameters and in the laboratory on hand-carved blocks taken during construction and after four years of service. The in situ and laboratory tests indicated that the hydraulic conductivity increased approximately three orders of magnitude (from ≈ 10?7?to? ≈ 10?4?cm?s?1) during the service life. A dye tracer test and soil structure analysis showed that extensive cracking and root development occurred throughout the entire depth of the barrier layer. Laboratory tests on undisturbed specimens of the clay barrier indicated that the hydraulic conductivity of damaged clay barriers can be underestimated significantly if small specimens (e.g., tube samples) are used for hydraulic conductivity assessment. The findings also indicate that clay barriers must be protected from desiccation and root intrusion if they are expected to function as intended, even at sites in warm, humid locations.