Water temperature and conductivity variability as indicators of groundwater behaviour in complex aquifer systems in the south‐east of Spain     

L. Molina  A. Vallejos  A. Pulido‐Bosch  F. Snchez‐Martos 《水文研究》2002,16(17):3365-3378

Groundwater temperature and electrical conductivity logs were applied in this study to gain an understanding of the hydrogeological behaviour of a complex system. This system, compartmentalized by a large number of fractures, which may even cause geothermal anomalies, is that of the Campo de Dalías in the south‐east of the Iberian Peninsula. In addition to this complexity one must consider the different levels with aquifer properties and their varying lithologies, which in some cases are in direct contact with the sea. Vertical sections based upon the various logs allow lateral correlation to be made between the anomalies detected, and provide information on the existence of both ascending and descending vertical flows, and the inflow of sea water into the system. Analysis of environmental isotopes (¹⁸O and D) indicate the areas of recharge with the greatest flow velocity. No seasonal variation in the isotopes was observed, which suggests that the residence time of the groundwater in the aquifer is several years. Radiocarbon dating gave estimates of generally long residence times, although in some sectors it is possible to detect the current recharge based on its tritium content, from rainwater infiltration or seawater intrusion. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Synthetic information prediction system for crisis mine based on GIS     

Yuxin Ye  Ping Yu  Shi Wang  Shuisheng Ye 《世界地质(英文版)》2006,9(1)

Reserves of some kinds of the crisis mines will be lack now or from now on, because of lacking seriously reserves of mineral resources and the crisis of exploring bases in support. So that it is urgent to predict, appraise, development and utilize the replaceable resources of the crisis mines. The mineral resources prediction software system of synthetic information is intelligent GIS which is used to quantitative prediction of large-scale synthetic information mineral target. It takes the geological body and the mineral resource body as a unit. And it analyzes the ore deposit genesis and metallotect, knows the spatial distribution laws of the ore deposit and ore body, and establish the prospecting model based on the concept of establishing the three-dimensional space of a mine. This paper will primarily discuss some important problems as follows: the secondary development of various kinds of data(including geology, geophysical prospecting, geochemical prospecting and remote sensing, etc); process synthetically and establish the synthetic information interpretative map base; correspond prospecting model with synthetic information of ore deposit; divided into statistical units of metallogenic information synthetic anomalies based on the synthetic information anomalies of ore control, then research the metallogenic information variable of unit synthetically and make quantitative prediction according to choose the quantitative prediction math model which is suitable to the demands of large-scale precision; at last, finish the target area optimization of ore deposit (body).  相似文献   

Spatial changes in a macrozoobenthic community along environmental gradients in a shallow brackish lagoon facing Sendai Bay, Japan   总被引：3，自引：0，他引：3  

Gen Kanaya  Eisuke Kikuchi   《Estuarine, Coastal and Shelf Science》2008,78(4):674-684

The spatial distribution, abundance, and assemblage structure of macrozoobenthos were examined at 45 stations in a brackish lagoon (Idoura Lagoon, Japan) to examine the animal–environmental relations in estuarine soft-bottom habitats. We found a total of 23 taxa; the polychaetes Heteromastus sp., Hediste spp., and Prionospio japonica and the isopod Cyathura muromiensis numerically dominated the community. Cluster analysis and one-way analysis of similarity (ANOSIM) identified seven groups of stations that had significantly different macrozoobenthic communities; these were subsequently consolidated into five habitat groups according to their association with environmental characteristics. Canonical correspondence analysis (CCA) showed that salinity, silt-clay content, and the oxidation–reduction potential (ORP) of the sediment strongly affected the macrozoobenthos distribution pattern in the lagoon, whereas other factors (e.g., relative elevation of the habitat and sediment organic content) had much weaker effects. Similarity percentages (SIMPER) procedures indicated that the polychaete Notomastus sp. and the bivalve Macoma contabulata were specific to habitats with low salinity and reduced mud, whereas the bivalve Nuttallia olivacea was specific to sandy bottoms. Heteromastus sp. and Hediste spp. achieved their highest densities in rather oxidized sediments. The acid-volatile sulfide (AVS) content in the sediment was suggested as another possible factor affecting macrozoobenthic density. Our results clearly demonstrate that macrozoobenthic assemblages in estuarine soft-bottoms have high spatial heterogeneity on a small scale (e.g., hundreds of meters) related to physical and chemical environmental changes. Our data also suggested the importance of sediment redox condition (e.g., ORP and AVS content) and sediment grain size as structuring factors in estuarine soft-bottom communities as well as the salinity in the habitat.  相似文献   

北黄海温盐分布季节变化特征分析   总被引：9，自引：1，他引：8  

鲍献文  李娜  姚志刚  吴德星 《中国海洋大学学报(自然科学版)》2009,39(4)

利用2006～2007年夏冬春秋4个季节北黄海的大面调查资料,分析了4个季节北黄海温度和盐度大面以及典型断面分布特征,得出以下结论:2007年冷水团势力范围强于2006年,北黄海冷水团的形成受地形影响.黄海暖流冬春季较强,冬季最强,夏季最弱,秋季开始形成.鲁北沿岸流冬季最强,春季减弱,夏秋季消失,但夏季鲁北沿岸存在冬季鲁北沿岸流水的残余体,即鲁北沿岸水.辽南沿岸水4个季节都以低盐为特征,除夏季低盐中心位于庄河口外,其它3个季节低盐中心均位于调查区域的东北角.渤海与北黄海之间的水交换4个季节都存在.春季,断面盐跃层形成滞后于温跃层;秋季,断面盐跃层消失滞后于温跃层.  相似文献   

Surface sediment diatoms from the western Pacific marginal seas and their correlation to environmental variables     

黄玥  蒋辉  Svante Bjrck  李铁刚  吕厚远  冉莉华 《中国海洋湖沼学报》2009,27(3):674-682

Diatom data of 192 surface sediment samples from the marginal seas in the western Pacific together with modern summer and winter sea surface temperature and salinity data were analyzed.The results of canonical correspondence analysis show that summer sea-surface salinity(SSS) is highly positively correlated with winter SSS and so is summer sea-surface temperature(SST) with winter SST.The correlations between SSSs and SSTs are less positively correlated,which may be due to interactions of regional current pa...  相似文献   

水污染物浓度的神经网络预测模式及效果检验     

于扬  薛丽梅  聂伊辰 《成都信息工程学院学报》2004,19(1):100-103

污染物浓度预测是环境保护的重要内容,将神经网络用于水中有机污染物浓度的预测并对效果进行检验.结果表明,预测值与观测值符合较好.  相似文献   

成矿定量预测与深部找矿   总被引：19，自引：1，他引：18  

赵鹏大 《地学前缘》2007,14(5):1-10

成矿预测是在不确定条件下制定最优决策的工作。成矿预测作为一种地质系统,与其他技术、经济系统存在重要区别。由于矿床类型的多样性,矿床成因的复杂性,控矿因素的隐蔽性和找矿信息的多解性,成矿预测结果具有不确定性并常常因人而异。探索成矿预测过程客观化、定量化和精确化一直是成矿预测学的前沿课题。文中以个旧锡矿为例展示致矿地质异常与矿体空间产出及分布的密切关系,强调以"求异"准则为指导的成矿定量预测的重要性。当今地质勘查工作面临深部找矿问题,论文从深部找矿的概念、类型、目标、效益等方面简要介绍了国外理论研究和找矿实践概况。强调深部找矿中要加强地壳深部结构的研究,要重视深部找矿的经济"回报率"和勘查项目的"转化率"的重要性。  相似文献   

利用人工鱼群算法优化高斯过程模型及应用分析     

邱小梦  周世健  王奉伟  欧阳亮酉 《测绘通报》2018,(1):157-160,164

基于高斯过程利用传统共轭梯度法搜索超参数,存在对初始值依赖性强、获得局部最优解的不足。本文采用人工鱼群算法对超参数进行智能寻优,建立了基于人工鱼群算法的高斯过程模型对变形体形变进行预测分析。通过隧道和基坑两个工程实例计算比对分析,NN、SE和RQ 3种核函数中NN核函数的预测效果最好,平均相对误差分别为0.69%和1.06%。结果表明超参数优化模型的预测精度得到了较大的提高,改善了高斯过程算法本身存在的超参数求解方面的不足,效果明显。  相似文献   

填埋场单井注气气体压力监测试验及预测模型     

金佳旭  朱磊  刘磊  陈亿军  姚远  高腾飞  李若欣 《岩土力学》2023,44(1):259-267

确定填埋场注气过程中气体压力分布特征可为好氧通风工程提供关键技术和理论支撑。以现场单井注气试验为依托,在渗流力学理论的基础上,开展了不同注气强度条件下气体压力分布监测试验,分析了注气过程中气体压力的径向分布特征,推导了注气条件下垃圾土体内部以解析解形式表达的气体压力预测（analytical gas pressure prediction,简称AGPP）模型;结合现场气体压力监测结果,构建了以注气井压力为核心参数的经验公式形式的气体压力预测（empiricalgaspressure prediction,简称EGPP）模型。试验结果表明：低压注气强度也可以达到良好的注气效果,在较短时间内可以让气体充满注气井周围;通过现场监测数据与AGPP模型、EGPP模型的对比,初步验证了两种模型的可靠性。以上成果为预测和评估好氧通风过程中垃圾填埋场气体压力分布提供了新方法。  相似文献   

贵州铜仁地区锰矿定量预测与评价     

李素雅  陈建平  刘畅 《江苏地质》2023,47(2):166-174

应用地质、化探、物探、遥感等手段和资料进行多元信息成矿预测已成为找矿工作的重要方法。以贵州铜仁地区锰矿为研究对象,基于研究区与成矿相关的多元信息,建立区域找矿模型;运用GIS技术对多元信息进行综合处理并提取有利成矿信息,形成找矿标志专题图层,构成找矿预测指标集;利用证据权重法建立锰矿综合预测模型,结合研究区成矿地质条件、已知锰矿床（点）等因素,确定找矿有利地区,并圈定7个远景区,为发现大规模锰矿产地提供参考。  相似文献