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排序方式: 共有2091条查询结果,搜索用时 31 毫秒
981.
SUN Dong LIU Xin-ze YANG Hai-jun CAO Nan ZHANG Zhi-peng CHEN Yin-song LI Da-meng 《地下水科学与工程》2019,7(3):195-213
Studying the influence of shale gas exploration and development on groundwater environment is the basis of guiding water environment protection in the process of shale gas exploration and development.Groundwater environmental pollution is concealed,complex and persistent.Once it is difficult to control the pollution,the current commercial shale gas development zones in Sichuan Basin that are mostly located in karst areas and highly sensitive to groundwater will be vulnerable to the impact of shale gas exploration and development.Based on the hydrogeological conditions of shale gas exploration and development area and combined with engineering analysis of exploration and development,various risk pathways that may affect the groundwater environment during process of shale gas exploration,mining well construction,mining operations and other stages were identified in this paper.Some existing risk pathways were proved by verification of typical areas and should not be ignored.Based on the actual situation of typical areas,the countermeasures of groundwater environmental protection in the process of shale gas exploration and development in karst areas were discussed.It is believed that the groundwater environment can be better protected by strengthening administration,research and application of new technologies,precise design,hydrogeological conditions,and research and feedback of groundwater environmental protection. 相似文献
982.
贵州广顺二叠系化学地层的划分及沉积环境分析 总被引:2,自引:2,他引:2
本文以贵州省广顺二叠纪坝子头-茶叶剖面作了基准剖面,通过野外观察和室内岩相分析,根据岩石的成岩作用,颜色,微相特征及岩层的厚度和叠置关系,进行了层序的划分。在此基础上,以该剖面59个岩层的17个微量元素(As,B,Ba,Co,Cr,Cu,Ga,Mn,Mo,Ni,Pb,Sn,Sr,Ti,V,Zn和Zr)为变量,用因子分析和群分析进行了化学地层单元的划分,通过化学地层和层序地层划分结果的对比,结合化学 相似文献
983.
Nan D. Walker 《Estuaries and Coasts》2001,24(4):498-508
Changes in circulation, water level, salinity, suspended sediments, and sediment flux resulted from Tropical Storm Frances and Hurricane Georges in the Vermilion-Atchafalaya Bay region during September 1998. Tropical Storm Frances made landfall near Port Aransas, Texas, 400 km west of the study area, and yet the strong and long-lived southeasterly winds resulted in the highest water levels and salinity values of the year at one station in West Cote Blanche Bay. Water levels were abnormally high across this coastal bay system, although salinity impacts varied spatially. Over 24 h, salinity increased from 5 to 20 psu at Site 1 on the east side of West Cote Blanche Bay. Abnormally high salinities were recorded in Atchafalaya Bay but not at stations in Vermilion Bay. On September 28, 1998, Hurricane Georges made landfall near Biloxi, Mississippi, 240 km east of the study area. On the west side of the storm, wind stress was from the north and maximum winds locally reached 14 m s−1. The wind forcing and physical responses of the bay system were analogous to those experienced during a winter cold-front passage. During the strong, north wind stress period, coastal water levels fell, salinity decreased, and sediment-laden bay water was transported onto the inner shelf. As the north wind stress subsided, a pulse of relatively saline water entered Vermilion Bay through Southwest Pass increasing salinity from 5 to 20 psu over a 24-h period. National Oceanic and Atmospheric Administration (NOAA)-14 reflectance imagery revealed the regional impacts of wind-wave resuspension and the bay-shelf exchange of waters. During both storm events, suspended solid concentrations increased by an order of magnitude from 75 to over 750 mg l−1. The measurements demonstrated that even remote storm systems can have marked impacts on the physical processes that affect ecological processes in shallow coastal bay systems. 相似文献
984.
Chen Zongyu Institute of Hydrogeology Environmental Geology Chinese Academy of Geological Sciences Shijiazhuang College of Earth Sciences Jilin University Changchun Zhang Guanghui Ni Zhenlong Qi Jixiang Nan Yunju Institute of Hy 《中国地质大学学报(英文版)》2001,12(3)
INTRODUCTIONManystudiesofglobalchangesshowthatthehydrologicalcycleofacontinentalscalecanberelatedtoclimaticchanges(Andersonetal.,2 0 0 1;KarenandDara,2 0 0 1;MichaelandMichael,1999;Hugoetal.,1996 ;Larryetal.,1996 ) .Cur rentdistributionpatternsofdeuteriumandoxygen 18concen … 相似文献
985.
湖泊数据库数据结构详析 总被引:2,自引:0,他引:2
湖泊数据库为湖泊科学定量化研究、宏观决策分析提供了丰富的基础数据。对于如何提取数据库信息,为应用目的服务,必须了解湖泊数据库数据结构。本文概略地描述了湖泊数据信息种类,分析了湖泊空间信息和非空间信息的数据结构,尤其对关系数据库数据文件作了详细剖析,给出了调用数据文件的C语言源程序。 相似文献
986.
Infrared solar spectra on clear days were measured automatically by an infrared solarspectrometer(ISS)with 0.4 cm~(-1) resolution developed by us.A line-by line(LBL)computationmethod was used to calculate theoretical atmospheric absorption.In the wavelength range of 3.410—3.438 μm.the absorption is mainly due to atmospheric methane and water vapor.Columnatmospheric methane was retrieved from the recorded infrared solar spectra.The seasonal variationof column atmospheric methane in Hefei has been obtained from the measuremental data of nearly18 months since the April of 1997.and found that it is similar to that of background data.Theinstruments.principles of measurement and some of results were introduced,and the results arealso discussed briefly in the paper. 相似文献
987.
应用双向差分分析方法对青海地区5级以上地震、中国大陆西部、南北带及全国范围内发生的7级以上地震发生次数进行了计算,得到了该模型的理论预测结果;该方法对5.0级以上中强震的长趋势判定有一定的作用。 相似文献
988.
地图扫描矢量化问题分析 总被引:5,自引:0,他引:5
本文指出了地图扫描矢量化在全过程中所存在的若干问题,分析了问题的原因,并就部分问题提出了解决思路。为避免和减少误差,提高矢量化产品质量有一定实际意义。 相似文献
989.
基态修正时空数据模型的扩展及在土地产权产籍系统中的实现 总被引:32,自引:3,他引:32
分析了几种有代表性的时空数据模型的特点和存在的局限性,对基态修正模型进行了扩展和改进,提出了建立区段快速索引和变粒度索引因子方法,以及采用历史库,过程库和现实库对时空过程和时空关系进行描述的思路,并在开发的商业化的土地产权籍管理系统中得到实现的。 相似文献
990.
海洋沉积物热释光--潜在的天然气水合物找矿方法 总被引:10,自引:1,他引:10
概述了热释光的形成机理。从放射性方法探测油气藏的原理出发 ,提出了海洋沉积物热释光探测天然气水合物的可能性。对采自中国南海、东海的海底沉积物进行了有机烃、金属元素和热释光分析。结果表明 ,热释光与有机烃类呈正相关 ,天然气水合物形成和分解产生的碳酸钙、硫酸钙及硫酸钡沉淀是很好的热释光晶体 ,在矿物结晶过程中加入的微量金属元素对热释光起到调节作用。热释光不受有机污染的影响 ,灵敏度高 ,是很有前景的寻找天然气水合物的方法 相似文献