Simple method for estimating well yield potential through geostatistical approach in fractured crystalline rock formations

2020 ◽  
pp. 125719
Author(s):  
Hiroyuki Nakayama ◽  
Yasumasa Yamasaki ◽  
Kengo Ohashi ◽  
Shinji Nakaya
Keyword(s):  
Crystalline Rock ◽  
Yield Potential ◽  
Simple Method ◽  
Rock Formations ◽  
Geostatistical Approach ◽  
Well Yield

scholarly journals Novel Ensemble of MCDM-Artificial Intelligence Techniques for Groundwater-Potential Mapping in Arid and Semi-Arid Regions (Iran)

2020 ◽  
Vol 12 (3) ◽  
pp. 490 ◽  
Author(s):  
Alireza Arabameri ◽  
Saro Lee ◽  
John P. Tiefenbacher ◽  
Phuong Thao Thi Ngo
Keyword(s):  
Groundwater Resources ◽  
Groundwater Potential ◽  
Rate Curve ◽  
Yield Potential ◽  
Validation Dataset ◽  
Well Yield ◽  
Potential Map ◽  
Potential Mapping ◽  
Groundwater Potential Map ◽  
Groundwater Potential Mapping

The aim of this research is to introduce a novel ensemble approach using Vise Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR), frequency ratio (FR), and random forest (RF) models for groundwater-potential mapping (GWPM) in Bastam watershed, Iran. This region suffers from freshwater shortages and the identification of new groundwater sites is a critical need. Remote sensing and geographic information system (GIS) were used to reduce time and financial costs of rapid assessment of groundwater resources. Seventeen physiographical, hydrological, and geological groundwater conditioning factors (GWCFs) were derived from a spatial geo-database. Groundwater data were gathered in field surveys and well-yield data were acquired from the Iranian Department of Water Resources Management for 89 locations with high yield potential values ≥ 11 m3 h−1. These data were mapped in a GIS. From these locations, 62 (70%) were randomly selected to be used for model training, and the remaining 27 (30%) were used for validation of the model. The relative weights of the GWCFs were determined with an RF model. For GWPM, 220 randomly selected points in the study area and their final weights were determined with the VIKOR model. A groundwater potential map was created by interpolating the values at these points using Kriging in GIS. Finally, the area under receiver operating characteristic (AUROC) curve was plotted for the groundwater potential map. The success rate curve (SRC) was computed for the training dataset, and the prediction rate curve (PRC) was calculated for the validation dataset. Results of RF analysis show that land use and land cover, lithology, and elevation are the most significant determinants of groundwater occurrence. The validation results show that the ensemble model had excellent prediction performance (PRC = 0.934) and goodness-of-fit (SRC = 0.925) and reasonably high classification accuracy. The results of this study could aid management of groundwater resources and assist planners and decision makers in groundwater-investment planning to achieve sustainability.

III.—The Crystalline Rock Areas of the Piémontese Alps

1916 ◽  
Vol 3 (5) ◽  
pp. 198-205
Author(s):  
C. S. Du Riche Preller
Keyword(s):  
Preceding Paper ◽  
Crystalline Rock ◽  
New Classification ◽  
Rock Formations ◽  
Starting Point

In continuation of the preceding paper (Geol. Mag., April, p. 156) which, as a preliminary to the present one, outlined the new classification of the crystalline rock formations and the nomenclature of the pietre verdi of the Piémontese Alps, I now propose to briefly describe the principal pietre verdi areas with which I became familiar during a long stay on repeated occasions in Turin. This city, apart from its rich collections of the rocks and minerals of the Piémontese Alps, is a most central and convenient starting-point for examining the different valleys debouching into the plain of the Po from the magnificent crescent formed by the Maritime, Cottian, Grajan, and Penniue Alps, which, as seen from Turin, afford by far the most extensive and fascinating Alpine panorama in Italy.

Rock Properties Input to the Site Screening Process

1983 ◽  
Vol 26 ◽  
Author(s):  
Arthur A. Bauer ◽  
Joe E. Ratigan
Keyword(s):  
Thermal Loading ◽  
Crystalline Rock ◽  
Rock Properties ◽  
Nuclear Waste Repository ◽  
Screening Process ◽  
Design Elements ◽  
Rock Formations ◽  
Wide Range ◽  
Stochastic Parameters ◽  
The Impact

ABSTRACTThe site-screening process is designed to provide information on rock formations that will serve as the basis for recoximnding potentially suitable sites for locating a nuclear waste repository. While the application of criteria to extrinsic characteristics of the host rock, such as minimum depth and areal extent, are based on requiremnts associated with repository design and waste isolation, the significance of intrinsic characteristics (e.g., thermal conductivity, heat capacity, Young's modulus) is less firmly based. This is of particular importance with crystalline or grantitic-type rocks since they exhibit a wide range of canpositions and properties.The range of crystalline rock property variations has been defined and results describing the impact of these variations on repository thermal, mechanical, chemical, and hydrological performance constraints obtained. Results also are presented for various repository design options (emplacement mode, thermal loading, package power/pitch). For the analysis, rock properties and repository design elements are treated as stochastic parameters by statistical methods. The output range of a performance parameter is determined with respect to the range of stochastic parameters to establish their importance in site selection.

scholarly journals HYDROGEOPHYSICS IN FRACTURED CRYSTALLINE AQUIFERS IN ENGLISH GUYANA

2019 ◽  
Vol 37 (3) ◽  
pp. 299
Author(s):  
Gerlane Cavalcante Messias ◽  
Jose Agnelo Soares ◽  
Felipe Kipper ◽  
Igor Fernandes Gomes ◽  
Vandir Pereira Soares Júnior ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Crystalline Rock ◽  
Electrical Resistivity Imaging ◽  
Second Phase ◽  
Resistivity Imaging ◽  
Rock Formations ◽  
Controlled Porosity ◽  
Two Phases ◽  
Resistivity Meter

ABSTRACT: This work is a case study in Guyana with the goal of finding groundwater in rock layers with fracture-controlled porosity using electrical resistivity imaging. This work was carried out in two phases by the Brazilian Army, in eight communities in the region of Alto Tacutu – Alto Essequibo in southeast Guyana. All work was done in accordance with a technical agreement between Brazil and Guyana. In the first phase, the surveys were completed by the team which collected resistivity data using a SuperSting R8 electrical resistivity meter with dipole-dipole and dipole-gradient arrays. Then the software EarthImager was used to analyze the data and create two-dimensional (2D) pseudo-sections with depths up to 70m. In the second phase, eight wells were drilled in areas of low resistivity. The geology of this region consists of Precambrian granite rock layers with varying levels of fracturing. In this way, the effectiveness of the multielectrode resistivity imaging technique was demonstrated as a way to explore the availability of groundwater in crystalline rock formations with fracture-controlled porosity.Keywords: electrical resistivity imaging, well siting, groundwater.RESUMO: Este trabalho se constitui em um estudo de caso na Guiana Inglesa, com o objetivo de encontrar água subterrânea por meio de levantamentos de resistividade elétrica, nas áreas de porosidade controladas pelas zonas de fraturas. O trabalho foi realizado em duas fases pelo Exército Brasileiro em oito comunidades da região do Alto Tacutu – Alto Essequibo no sudeste da Guiana Inglesa, através de um acordo de cooperação técnica entre o Brasil e a Guiana. Na primeira fase, os levantamentos foram feitos por uma equipe que coletou dados de resistividade usando um eletrorresistivímetro SuperSting R8 com arranjos dos tipos dipolo-dipolo e dipolo gradiente. Em seguida foi utilizado o software EarthImager para analisar os dados e criar pseudoseções de duas dimensões (2D) até 70m de profundidade. Na segunda fase, oito poços foram perfurados em pontos de baixa resistividade. A geologia da região é constituída de rochas graníticas Pré-cambrianas com níveis variados de fraturamento. Desse modo, demonstrou-se a efetividade do método de resistividade elétrica multieletrodo para explorar a disponibilidade de água subterrânea em aquíferos fraturados em terrenos cristalinos.Palavras-chave: imageamento de resistividade elétrica, locação de poços, água subterrânea.

Modeling of Glass Dissolution and Transport With the Code SUGAR

1997 ◽  
Vol 506 ◽  
Author(s):  
J.S. Small ◽  
D.P. Trivedi ◽  
P.K. Abraitisti
Keyword(s):  
Reactive Transport ◽  
Preliminary Investigation ◽  
Radioactive Decay ◽  
Chemical Species ◽  
Steel Corrosion ◽  
Crystalline Rock ◽  
Geochemical Evolution ◽  
One Dimensional ◽  
Glass Dissolution ◽  
Rock Formations

ABSTRACTSUGAR (Simplified Understading of Glass And environment Reactions) is a one dimensional (lD) reactive transport code which sequentially couples dissolved chemical species transport and sorption with, chemical speciation, mineral precipitation and kinetic controlled glass dissolution. SUGAR also has the capability to model radioactive decay and steel corrosion. This paper describes the computer model and presents results of model testing against experimental data. The capabilities of the model are demonstrated by a preliminary investigation of the geochemical evolution of glass in crystalline rock formations.

scholarly journals Progressive Damage of a Canadian Granite in Laboratory Compression Tests and Underground Excavations

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Thanh Son Nguyen
Keyword(s):  
Constitutive Model ◽  
Mechanical Model ◽  
Rock Type ◽  
Past Research ◽  
Crystalline Rock ◽  
Published Data ◽  
Progressive Damage ◽  
Compression Tests ◽  
Rock Formations ◽  
Underground Research Laboratory

The crystalline rock formations of the Canadian Shield are currently one candidate rock type for the geological disposal of radioactive waste in Canada. This article starts with a critical review of past research results on the geomechanical behaviour of Lac du Bonnet granite, a rock type found at an Underground Research Laboratory (URL) in Pinawa, Manitoba, Canada. Based on the published data, a constitutive model was developed, based on Mohr-Coulomb plasticity, which includes the concept of asynchronous degradation of cohesion and mobilization of friction with progressive damage, as well as time-dependent degradation of strength. The constitutive model was used to simulate laboratory compression tests. It was then implemented in a coupled hydro-mechanical model to simulate the response of the rock mass induced by excavation of a test tunnel at 420 m depth at the URL.

Domestic well database development and integration into a GIS: an approach for managing ground water resources

2013 ◽  
Vol 13 (4) ◽  
pp. 993-1006
Author(s):  
Meredith J. Metcalf ◽  
Gary A. Robbins
Keyword(s):  
Water Supply ◽  
Ground Water ◽  
Water Resource ◽  
Data Entry ◽  
Resource Planning ◽  
Crystalline Rock ◽  
Water Resource Planning ◽  
Crystalline Bedrock ◽  
Well Yield ◽  
Ground Water Resource

Connecticut is dominated by rural communities which rely upon individual domestic wells in fractured crystalline bedrock for water supply. The individualized nature of ground water usage has made ground water resource planning on a regional or townwide basis non-existent. In recent years there has been increased development and concerns expressed regarding the sustainability of the fractured crystalline rock water supply and its quality, and the need for ground water resource planning. In this study, using a rural quadrangle in eastern Connecticut, we have developed a database system that is tied to a geographic information system that can be used to help manage and assess ground water conditions. The data in the database were derived using available water completion reports and water quality reports. Data query schemes were developed to screen for data entry and reporting errors. The information maintained in the database has been analyzed to derive products on well yield, well depth, and water elevation. These products are beneficial to town planners, local sanitarians, developers, homeowners, and drillers. They can improve and facilitate decision-making concerning future rural development to ensure ground water sustainability.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

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