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1.
物探方法是寻找地下水的重要勘查手段之一.在查明区域水文地质条件的基础上,本文采用音频大地电磁测深和高密度电阻率法对海南省琼中县榕木村花岗岩区深部赋水断裂破碎带的位置、深度、规模和产状特征进行了探测,结果表明:赋水断裂破碎带主要表现为"凹槽"状或"条带"状低阻异常;可以采用激电半衰时(Th)、偏离度(r)以及视电阻率(ρs)等参数进行断裂破碎带含水层位置判别.通过水文地质钻探揭露,含水层位置与物探解译结果基本一致,证明激电半衰时和偏离度以及视电阻率等参数可以较可靠地确定赋水构造的位置和深度.综合物探勘查方法为水文地质钻井孔位设计提供了有效技术支撑,可对在类似地区进行地下水探测提供参考. 相似文献
2.
泰安地区岩溶富水构造激电测深法异常类型 总被引：2，自引：0，他引：2
大量的抗旱打井找水开发深层岩溶地下水资源实例证明,泰安岩溶区不同岩溶形态富水构造激电测深异常类型及成因有一定规律可循.富水构造上的电测深曲线异常类型可划分为缓升型、缓降型、低阻V型、低阻平台型,富水地段电测深视电阻率断面等值线异常类型可划分为低阻台阶型、低阻梯度带型、低阻U型.以溶洞等岩溶形态为主的富水带引起相对低视电阻率、低视极化率、低半衰时及衰减度低异常,出现激电测深法多参数“同步低”异常;以断层构造破碎为主的富水带引起相对低视电阻率及低视极化率异常,产生相对高半衰时及衰减度极大值异常,出现视电阻率与激电测深法多参数“反相”异常. 相似文献
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在黑龙江省北部岛状冻土带上，使用WDJD-1多功能数字直流激电仪试验性找水，利用观测参数半衰时th、极化率ηs、衰减度D、视电阻率ρs等来推断含水层位、设计井深、估算涌水量、优选井位，研究结果表明该方法有一定的实用性。 相似文献
4.
激发极化法探测岩溶地下水主要是利用一次供电获得的视电阻率、视极化率、半衰时、衰减度多个含水参数值,依据各参数在含水岩体上的特征—低阻高极化、高半衰时、高衰减度的特征,通过对测深曲线和剖面等值线的综合分析,查明奥陶系灰岩岩溶裂隙发育情况,圈定岩溶富水区,最终为选定最佳井位、合理开发岩溶地下水资源提供科学依据：本文根据实测结果分析证明应用激发极化法在岩溶山区寻找岩溶裂隙水是行之有效的。 相似文献
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《物探与化探》2021,(3)
深度学习是人工神经网络算法的扩展,对复杂函数有很好的逼近能力,本文将其引入用于瞬变电磁视电阻率计算。首先,建立归一化感应电动势与瞬变场参数单一映射关系的5层深度神经网络,通过对单一隐含层不同神经元个数所训练的误差情况进行分析,确定5层深度神经网络各隐含层神经元个数为13,8,5,8,13。训练算法选择了改进的具有自适应学习率的Nadam算法,该算法可加速训练过程。对训练好的深度神经网络模型进行仿真实验,采用典型地电模型加以验证,发现其对不同的地电模型均具有较好的反映,证明本文采用的基于深度学习计算视电阻率的可行性。应用结果表明训练好的深度神经网络模型可快速准确计算视电阻率。 相似文献
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为揭示太行山北段岩溶裂隙水富水性分布规律,采用电阻率、极化率、半衰时和偏离度分析不同含水层介质结构、不同含水岩组和不同地下水系统岩溶裂隙水与电性参数的关系,探讨研究区岩溶裂隙水富水性的影响因素及其电性响应特征。结果表明:含水层介质结构按照溶蚀孔洞型→断层型→褶皱型→岩体阻水型的排列顺序,半衰时值分布范围依次降低,而偏离度值分布范围依次升高;四种电性参数对奥陶系含水岩组、蓟县系含水岩组具有较强的分辨能力;极化率、半衰时和偏离度难以识别拒马河、界河－唐河以及瀑河－漕河三种岩溶裂隙地下水系统类型;奥陶系含水岩组的富水性优于蓟县系含水岩组;就含水层介质结构而言,溶蚀孔洞型富水性最佳,断层型和褶皱型次之,岩体阻水型富水性最差。 相似文献
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乌蒙山贫困缺水区水资源严重缺乏,找水需求大、难度大。为确定了ZK12探采结合井位置,本文首先分析了工区找水环境因素的地层时代、含水介质类型、构造背景、水源条件和水动条件等5个条件;其次,对富水特征的含水岩组、蓄水构造和富水地貌进行研究;最后,重点分析地球物理特征找水因素,介绍了视电阻率联合剖面法、大地电磁测深法、瞬变电磁法、激电测深和地球物理测井等“多方法”应用效果,通过视电阻率、视极化率、衰减度、半衰时等“多参数”,确定断层裂隙水的地球物理特征,建立由浅入深的“多层次”地球物理模式。最终,创新性提出了乌蒙山连片贫困缺水区重点村镇的“多方法、多参数、多层次”地球物理找水模式,克服单一物探方法找水的局限性,精准定井位,对地下水勘查起到示范作用。 相似文献
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王程 《物探化探计算技术》2023,(5):597-603
突水灾害在隧(巷)道等隐蔽工程中是重大安全隐患,查明隐伏的强富水区域是亟需研究和解决的重要工程需求,其中水量的预测是重难点。针对此问题,这里开展激电法半衰时探水技术的研究,基于岩石电化学测试分析不同孔隙度含水量条件下相关参数的规律,采用物理模拟实验研究二次时差与含水量之间关系。研究表明：(1)电阻率与孔隙度含水量之间为正线性相关,极化率和半衰时与孔隙度含水量之间近似“正态”相关;(2)二次时差法探水机理中二次时差与含水量关系较为复杂,并非简单的线性相关,二次时差法需基于较多已知条件方可粗略估算含水量,目前该方法实际应用仅可作为探水的辅助手段。 相似文献
11.
Ahmad Neyamadpour W. A. T. Wan Abdullah Samsudin Taib 《Journal of Earth System Science》2010,119(1):27-40
The objective of this paper is to investigate the applicability of artificial neural networks in inverting quasi-3D DC resistivity
imaging data. An electrical resistivity imaging survey was carried out along seven parallel lines using a dipole-dipole array
to confirm the validation of the results of an inversion using an artificial neural network technique. The model used to produce
synthetic data to train the artificial neural network was a homogeneous medium of 100Ωm resistivity with an embedded anomalous
body of 1000Ωm resistivity. The network was trained using 21 datasets (comprising 12159 data points) and tested on another
11 synthetic datasets (comprising 6369 data points) and on real field data. Another 24 test datasets (comprising 13896 data
points) consisting of different resistivities for the background and the anomalous bodies were used in order to test the interpolation
and extrapolation of network properties. Different learning paradigms were tried in the training process of the neural network,
with the resilient propagation paradigm being the most efficient. The number of nodes, hidden layers, and efficient values
for learning rate and momentum coefficient have been studied. Although a significant correlation between results of the neural
network and the conventional robust inversion technique was found, the ANN results show more details of the subsurface structure,
and the RMS misfits for the results of the neural network are less than seen with conventional methods. The interpreted results
show that the trained network was able to invert quasi-3D electrical resistivity imaging data obtained by dipole-dipole configuration
both rapidly and accurately. 相似文献
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珠江口盆地的低阻油层具有高泥质含量、低电阻率以及低产能的特点, 其真实含油饱和度的确定存在很大的困难。首先分析了区域低阻油层的地质成因, 指出地层束缚水含量高, 以及由此形成的发达的导电网络是导致油层低阻的主要原因;在此基础上, 利用多种适合于泥质砂岩地层的饱和度模型进行计算, 并根据密闭取心资料, 重点分析了在不同地层条件下, 对岩样含油、水饱和度进行脱气校正、压实校正、体积系数校正以及漏失校正的方法;并结合核磁共振测井, 对测井计算的含水饱和度进行标定。结果显示, 低阻油层的含水饱和度平均在70%以上, 且印度尼西亚公式计算的含水饱和度与岩心校正后的饱和度以及核磁束缚水饱和度吻合均很好, 因此印度尼西亚公式是最适合本区域低阻油层的饱和度评价模型。 相似文献
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通常平原城市河网水动力条件较差,加快水体更新、增强水体的流动性可改善河网水环境质量。以长江下游典型平原城市启东市为例,充分利用河道天然潮动力条件,建立河网水动力学模型,通过数值模拟试验,量化分析优化水系格局、工程布局和调度方式对河网水体流动性的改善程度。结果表明：在最不利潮汐条件下,优化方案可将河网的全历时生态流速达标率由52.3%提升至94.2%,最大瞬时生态流速达标率由42.6%提升至85.0%,区域生态流速持续度达91.8%,同时还可节约67.5%的引调水量;改善水系格局、优化河网控制工程布局及其调度方案可以减少域外引水,同时显著增加河网水流更新速率,降低污染物滞留时间,从而改善水环境。该方法可为提升平原城市感潮河网水环境质量提供新手段。 相似文献
15.
煤层含气量预测是煤层气资源勘探开发利用前期的重要研究内容之一。近些年,BP神经网络算法常用于煤层含气量预测领域,但传统BP模型在训练过程中往往存在收敛速度慢、对初始值敏感以及易陷入局部极小值等问题。为此,提出了一种改进的以人工蜂群算法为特征的BP神经网络预测方法。以沁水盆地某工区3号煤层为研究对象,首先,利用R型聚类分析法对目标煤储层所提取的多种类型的地震属性进行分类,优选出4种对煤层含气量变化反应最敏感且相互独立的地震属性;再利用人工蜂群算法(ABC)寻找BP神经网络的输入层与隐含层的最优连接权值和隐含层的最优阈值,构建具有鲁棒性的ABC-BP神经网络预测模型,并以井位置优选地震属性和含气量数据为样本训练该模型;最后,以整个工区目标储层的优选地震属性为输入,进行工区内煤层含气量的预测。预测结果与各井含气量的变化趋势基本吻合,其中,训练井处的平均误差率为0.23%,验证井处的误差率低于15%,预测精度较高,因此,该预测方法可靠性高,适用性强,可有效用于煤层含气量预测。 相似文献
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A Stanley Raj Y SRINIVAS D Hudson Oliver D Muthuraj 《Journal of Earth System Science》2014,123(2):395-411
The non-linear apparent resistivity problem in the subsurface study of the earth takes into account the model parameters in terms of resistivity and thickness of individual subsurface layers using the trained synthetic data by means of Artificial Neural Networks (ANN). Here we used a single layer feed-forward neural network with fast back propagation learning algorithm. So on proper training of back propagation networks it tends to give the resistivity and thickness of the subsurface layer model of the field resistivity data with reference to the synthetic data trained in the appropriate network. During training, the weights and biases of the network are iteratively adjusted to make network performance function level more efficient. On adequate training, errors are minimized and the best result is obtained using the artificial neural networks. The network is trained with more number of VES data and this trained network is demonstrated by the field data. The accuracy of inversion depends upon the number of data trained. In this novel and specially designed algorithm, the interpretation of the vertical electrical sounding has been done successfully with the more accurate layer model. 相似文献
17.
将南京下蜀土与中砂以不同比例混合,配制了四种土样,利用室内四极法分别测试了每种土样在不同含水率条件下
的电阻率,发现随含水率和黏土颗粒含量的增加,土体电阻率减小;同时,采用DRE导热系数测试仪测试了每个试样的导
热系数,发现随含水率和砂含量的增高,导热系数增大。已有研究表明,土的电阻率与导热系数均与土体饱和度及孔隙率
等物理性质有关。通过将土的电阻率与导热系数进行拟合,发现两者符合指数关系,并建立了表征电阻率与导热系数相关
性的数学模型。该文研究结果为利用现场实测的电阻率指标间接求取土体的导热系数提供了依据。 相似文献
18.
疏勒河中下游地区的地表水及地下水资源在尚未开发利用之前 ,在时空分配上处于天然平衡状态。但人为调配水资源 (如拦河蓄水、引水灌溉 )后 ,戈壁带及前缘带 (地下水径流带 )潜水位一直处于下降趋势 ,而细土平原带潜水位有上升趋势 ,从而导致了植被群落的衰亡 ,不同程度地引发了土地资源的沙漠化和次生盐渍化等环境地质问题。为确保该区的生态环境及农业生产的稳步发展 ,提出了多目标规划管理模型。 相似文献
19.
Fathy Shaaban Ahmed Ismail Usama Massoud Hany Mesbah Ahmed Lethy Abbas Mohamed Abbas 《Arabian Journal of Geosciences》2013,6(12):4961-4972
The flood plain of the Nile River has been a safe dwelling throughout history. Recently with a growing population and vast growing urbanization, some buildings have started to experience structural damages, which are not related to their construction design, but rather to the ground conditions around the buildings' foundations. Variations in properties of the soil supporting the buildings' foundations such as soil-bearing capacity, moisture content, and scouring may eventually lead to the failure of these buildings. This study is attempting to characterize the variations in the soil properties around the City Star shopping mall, in eastern Cairo, where a large building has tilted over the past few years. This tilting may lead to the collapse of the whole building if it continues at the same rate. An integrated geophysical investigation including multi-channel analysis of surface wave (MASW), ground-penetrating radar (GPR), and 2-D electrical resistivity tomography (ERT) was used around the affected building to help detect possible causes of deterioration. The GPR data showed a soil-filled layer overlaying a thick bottom layer of higher moisture content. The MASW data revealed a middle layer of relatively low shear wave velocity sandwiched between two relatively high shear wave velocity layers. The ERT data showed an upper low resistivity layer overlying a high resistivity layer. Integrating the interpretations of the three geophysical methods provides a combined model that reflects lateral and vertical variation in the soil properties. This variation becomes dramatic near the tilted corner of the building. 相似文献
20.
ZhouPinggen 《中国地质大学学报(英文版)》2003,14(2):161-165
The factors of geomorphology, geological setting, effect of ground water and environment dynamic factors (e.g. rainfall and artificial water recharge) should be integrated in the discrimination of the stability of the ancient landslide. As the criterion of landslide stability has been studied, the artificial neural network model was then applied to discriminate the stability of the ancient landslide in the impounding area of the Three Gorges project on the Yangtze River, China. The model has the property of self-adaptive identifying and integrating complex qualitative factors and quantitative factors. The results of the artificial neural network model are coincided well with what were gained by classical limit equilibrimm analysis (the Bishop method and Janbu method) and by other comprehensive discrimination methods. 相似文献