WorldWideScience

Sample records for groundwater level map

  1. Method for the Preparation of Hazard Map in Urban Area Using Soil Depth and Groundwater Level

    Science.gov (United States)

    Kim, Sung-Wook; Choi, Eun-Kyeong; Cho, Jin Woo; Lee, Ju-Hyoung

    2017-04-01

    The hazard maps for predicting collapse on natural slopes consists of a combination of topographic, hydrological, and geological factors. Topographic factors are extracted from DEM, including aspect, slope, curvature, and topographic index. Hydrological factors, such as distance to drainage, drainage density, stream-power index, and wetness index are most important factors for slope instability. However, most of the urban areas are located on the plains and it is difficult to apply the hazard map using the topography and hydrological factors. In order to evaluate the risk of collapse of flat and low slope areas, soil depth and groundwater level data were collected and used as a factor for interpretation. In addition, the reliability of the hazard map was compared with the disaster history of the study area (Gangnam-gu and Yeouido district). In the disaster map of the disaster prevention agency, the urban area was mostly classified as the stable area and did not reflect the collapse history. Soil depth, drainage conditions and groundwater level obtained from boreholes were added as input data of hazard map, and disaster vulnerability increased at the location where the actual collapse points. In the study area where damage occurred, the moderate and low grades of the vulnerability of previous hazard map were 12% and 88%, respectively. While, the improved map showed 2% high grade, moderate grade 29%, low grade 66% and very low grade 2%. These results were similar to actual damage. Keywords: hazard map, urban area, soil depth, ground water level Acknowledgement This research was supported by a Grant from a Strategic Research Project (Horizontal Drilling and Stabilization Technologies for Urban Search and Rescue (US&R) Operation) funded by the Korea Institute of Civil Engineering and Building Technology.

  2. Comparison of stochastic and deterministic methods for mapping groundwater level spatial variability in sparsely monitored basins.

    Science.gov (United States)

    Varouchakis, Epsilon A; Hristopulos, D T

    2013-01-01

    In sparsely monitored basins, accurate mapping of the spatial variability of groundwater level requires the interpolation of scattered data. This paper presents a comparison of deterministic interpolation methods, i.e. inverse distance weight (IDW) and minimum curvature (MC), with stochastic methods, i.e. ordinary kriging (OK), universal kriging (UK) and kriging with Delaunay triangulation (DK). The study area is the Mires Basin of Mesara Valley in Crete (Greece). This sparsely sampled basin has limited groundwater resources which are vital for the island's economy; spatial variations of the groundwater level are important for developing management and monitoring strategies. We evaluate the performance of the interpolation methods with respect to different statistical measures. The Spartan variogram family is applied for the first time to hydrological data and is shown to be optimal with respect to stochastic interpolation of this dataset. The three stochastic methods (OK, DK and UK) perform overall better than the deterministic counterparts (IDW and MC). DK, which is herein for the first time applied to hydrological data, yields the most accurate cross-validation estimate for the lowest value in the dataset. OK and UK lead to smooth isolevel contours, whilst DK and IDW generate more edges. The stochastic methods deliver estimates of prediction uncertainty which becomes highest near the southeastern border of the basin.

  3. Mapping groundwater level and aquifer storage variations from InSAR measurements in the Madrid aquifer, Central Spain

    Science.gov (United States)

    Béjar-Pizarro, Marta; Ezquerro, Pablo; Herrera, Gerardo; Tomás, Roberto; Guardiola-Albert, Carolina; Ruiz Hernández, José M.; Fernández Merodo, José A.; Marchamalo, Miguel; Martínez, Rubén

    2017-04-01

    Groundwater resources are under stress in many regions of the world and the future water supply for many populations, particularly in the driest places on Earth, is threatened. Future climatic conditions and population growth are expected to intensify the problem. Understanding the factors that control groundwater storage variation is crucial to mitigate its adverse consequences. In this work, we apply satellite-based measurements of ground deformation over the Tertiary detritic aquifer of Madrid (TDAM), Central Spain, to infer the spatio-temporal evolution of water levels and estimate groundwater storage variations. Specifically, we use Persistent Scatterer Interferometry (PSI) data during the period 1992-2010 and piezometric time series on 19 well sites covering the period 1997-2010 to build groundwater level maps and quantify groundwater storage variations. Our results reveal that groundwater storage loss occurred in two different periods, 1992-1999 and 2005-2010 and was mainly concentrated in a region of ∼200 km2. The presence of more compressible materials in that region combined with a long continuous water extraction can explain this volumetric deficit. This study illustrates how the combination of PSI and piezometric data can be used to detect small aquifers affected by groundwater storage loss helping to improve their sustainable management.

  4. Maps showing ground-water levels, springs, and depth to ground water, Basin and Range Province, Texas

    Science.gov (United States)

    Brady, B.T.; Bedinger, M.S.; Mulvihill, D.A.; Mikels, John; Langer, W.H.

    1984-01-01

    This report on ground-water levels, springs, and depth to ground water in the Basin and Range province of Texas (see index map) was prepared as part of a program of the U.S. Geological Survey to identify prospective regions for further study relative to isolation of high-level nuclear waste (Bedinger, Sargent, and Reed, 1984), utilizing program guidelines defined in Sargent and Bedinger (1984). Also included in this report are selected references on pertinent geologic and hydrologic studies of the region. Other map reports in this series contain detailed data on ground-water quality, surface distribution of selected rock types, tectonic conditions, areal geophysics, Pleistocene lakes and marshes, and mineral and energy resources.

  5. Excel Spreadsheet Tools for Analyzing Groundwater Level Records and Displaying Information in ArcMap

    Science.gov (United States)

    Tillman, Fred D

    2009-01-01

    When beginning hydrologic investigations, a first action is often to gather existing sources of well information, compile this information into a single dataset, and visualize this information in a geographic information system (GIS) environment. This report presents tools (macros) developed using Visual Basic for Applications (VBA) for Microsoft Excel 2007 to assist in these tasks. One tool combines multiple datasets into a single worksheet and formats the resulting data for use by the other tools. A second tool produces summary information about the dataset, such as a list of unique site identification numbers, the number of water-level observations for each, and a table of the number of sites with a listed number of water-level observations. A third tool creates subsets of the original dataset based on user-specified options and produces a worksheet with water-level information for each well in the subset, including the average and standard deviation of water-level observations and maximum decline and rise in water levels between any two observations, among other information. This water-level information worksheet can be imported directly into ESRI ArcMap as an 'XY Data' file, and each of the fields of summary well information can be used for custom display. A separate set of VBA tools distributed in an additional Excel workbook creates hydrograph charts of each of the wells in the data subset produced by the aforementioned tools and produces portable document format (PDF) versions of the hydrograph charts. These PDF hydrographs can be hyperlinked to well locations in ArcMap or other GIS applications.

  6. [Construction of groundwater contamination prevention mapping system].

    Science.gov (United States)

    Wang, Jun-Jie; He, Jiang-Tao; Lu, Yan; Liu, Li-Ya; Zhang, Xiao-Liang

    2012-09-01

    Groundwater contamination prevention mapping is an important component of groundwater contamination geological survey and assessment work, which could provide the basis for making and implementing groundwater contamination prevention planning. A groundwater contamination prevention mapping system was constructed in view of the synthetic consideration on nature perspective derived from groundwater contamination sources and aquifer itself, social-economic perspective, policy perspective derived from outside. During the system construction process, analytic hierarchy process and relevant overlaying principles were used to couple groundwater contamination risk assessment, groundwater value as well as wellhead protection area zoning. Data processing and visualization of mapping results were achieved in the GIS environment. The research on groundwater contamination prevention mapping in Beijing Plain indicated that the final groundwater prevention map was in accordance with the actual conditions and well reflected the priorities of groundwater prevention, which could play a guidance role in designing and implementing further practical prevention and supervision measures. Besides, because of the dynamical properties of the system components, it was suggested to analyze the update frequency of the mapping.

  7. Groundwater levels for selected wells in Upper Kittitas County, Washington

    Science.gov (United States)

    Fasser, E.T.; Julich, R.J.

    2011-01-01

    Groundwater levels for selected wells in Upper Kittitas County, Washington, are presented on an interactive, web-based map to document the spatial distribution of groundwater levels in the study area measured during spring 2011. Groundwater-level data and well information were collected by the U.S. Geological Survey using standard techniques and are stored in the U.S. Geological Survey National Water Information System, Groundwater Site-Inventory database.

  8. Application of Remote Sensing for Generation of Groundwater Prospect Map

    Science.gov (United States)

    Inayathulla, Masool

    2016-07-01

    In developing accurate hydrogeomorphological analysis, monitoring, ability to generate information in spatial and temporal domain and delineation of land features are crucial for successful analysis and prediction of groundwater resources. However, the use of RS and GIS in handling large amount of spatial data provides to gain accurate information for delineating the geological and geomorphological characteristics and allied significance, which are considered as a controlling factor for the occurrence and movement of groundwater used IRS LISS II data on 1: 50000 scale along with topographic maps in various parts of India to develop integrated groundwater potential zones. The present work is an attempt to integrate RS and GIS based analysis and methodology in groundwater potential zone identification in the Arkavathi Basin, Bangalore, study area. The information on geology, geomorphology, soil, slope, rainfall, water level and land use/land cover was gathered, in addition, GIS platform was used for the integration of various themes. The composite map generated was further classified according to the spatial variation of the groundwater potential. Five categories of groundwater potential zones namely poor, moderate to poor, moderate, good and very good were identified and delineated. The hydrogeomorphological units like valley fills and alluvial plain and are potential zones for groundwater exploration and development and valley fills associated with lineaments is highly promising area for ground water recharging. The spatial variation of the potential indicates that groundwater occurrence is controlled by geology, land use / land cover, slope and landforms.

  9. A groundwater quality index map for Namibia

    Science.gov (United States)

    Bergmann, Thomas; Schulz, Oliver; Wanke, Heike; Püttmann, Wilhelm

    2016-04-01

    Groundwater quality and contamination is a huge concern for the population of Namibia, especially for those living in remote areas. There, most farmers use their own wells to supply themselves and their animals with drinking water. In many cases, except for a few studies that were done in some areas, the only groundwater quality measurements that took place were taken at the time the well was drilled. These data were collected and are available through the national GROWAS-Database. Information on measurements determining the amount of contaminants such as fluoride, TDS, other major ions and nitrate for several thousand wells are provided there. The aim of this study was I) to check the database for its reliability by comparing it to results from different studies and statistical analysis, II) to analyze the database on groundwater quality using different methods (statistical-, pattern- and correlation analysis) and III) to embed our own field work that took place within a selected Namibian region into that analysis. In order to get a better understanding of the groundwater problems in different areas of Namibia, a groundwater quality index map based on GROWAS was created using GIS processing techniques. This map uses several indicators for groundwater quality in relation to selected guidelines and combines them into an index, thus enabling the assessment of groundwater quality with regard to more than one pollutant. The goal of the groundwater quality map is to help identify where the overall groundwater quality is problematic and to communicate these problems. Additionally, suggestions for an enhancement of the database and for new field surveys will be given. The field work was focusing on three farms within an area known for its problematic nitrate concentration in groundwater. There, 23 wells were probed. In order to identify the sources of the contamination, isotopic measurements were executed for three of these wells with high nitrate concentrations

  10. Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin

    Science.gov (United States)

    Bartos, Timothy T.; Hallberg, Laura L.; Miller, Cheryl E.

    2015-07-14

    In cooperation with the Bureau of Land Management, groundwater levels in wells located in the northern Green River Basin in Wyoming, an area of ongoing energy development, were measured by the U.S. Geological Survey from 2010 to 2014. The wells were completed in the uppermost aquifers of the Green River Basin lower Tertiary aquifer system, which is a complex regional aquifer system that provides water to most wells in the area. Except for near perennial streams, groundwater-level altitudes in most aquifers generally decreased with increasing depth, indicating a general downward potential for groundwater movement in the study area. Drilled depth of the wells was observed as a useful indicator of depth to groundwater such that deeper wells typically had a greater depth to groundwater. Comparison of a subset of wells included in this study that had historical groundwater levels that were measured during the 1960s and 1970s and again between 2012 and 2014 indicated that, overall, most of the wells showed a net decline in groundwater levels.

  11. Groundwater vulnerability maps for pesticides for Flanders

    Science.gov (United States)

    Dams, Jef; Joris, Ingeborg; Bronders, Jan; Van Looy, Stijn; Vanden Boer, Dirk; Heuvelmans, Griet; Seuntjens, Piet

    2017-04-01

    Pesticides are increasingly being detected in shallow groundwater and and are one of the main causes of the poor chemical status of phreatic groundwater bodies in Flanders. There is a need for groundwater vulnerability maps in order to design monitoring strategies and land-use strategies for sensitive areas such as drinking water capture zones. This research focuses on the development of generic vulnerability maps for pesticides for Flanders and a tool to calculate substance-specific vulnerability maps at the scale of Flanders and at the local scale. (1) The generic vulnerability maps are constructed using an index based method in which maps of the main contributing factors in soil and saturated zone to high concentrations of pesticides in groundwater are classified and overlain. Different weights are assigned to the contributing factors according to the type of pesticide (low/high mobility, low/high persistence). Factors that are taken into account are the organic matter content and texture of soil, depth of the unsaturated zone, organic carbon and redox potential of the phreatic groundwater and thickness and conductivity of the phreatic layer. (2) Secondly a tool is developed that calculates substance-specific vulnerability maps for Flanders using a hybrid approach where a process-based leaching model GeoPEARL is combined with vulnerability indices that account for dilution in the phreatic layer. The GeoPEARL model is parameterized for Flanders in 1434 unique combinations of soil properties, climate and groundwater depth. Leaching is calculated for a 20 year period for each 50 x 50 m gridcell in Flanders. (3) At the local scale finally, a fully process-based approach is applied combining GeoPEARL leaching calculations and flowline calculations of pesticide transport in the saturated zone to define critical zones in the capture zone of a receptor such as a drinking water well or a river segment. The three approaches are explained more in detail and illustrated

  12. Custom map projections for regional groundwater models

    Science.gov (United States)

    Kuniansky, Eve L.

    2017-01-01

    For regional groundwater flow models (areas greater than 100,000 km2), improper choice of map projection parameters can result in model error for boundary conditions dependent on area (recharge or evapotranspiration simulated by application of a rate using cell area from model discretization) and length (rivers simulated with head-dependent flux boundary). Smaller model areas can use local map coordinates, such as State Plane (United States) or Universal Transverse Mercator (correct zone) without introducing large errors. Map projections vary in order to preserve one or more of the following properties: area, shape, distance (length), or direction. Numerous map projections are developed for different purposes as all four properties cannot be preserved simultaneously. Preservation of area and length are most critical for groundwater models. The Albers equal-area conic projection with custom standard parallels, selected by dividing the length north to south by 6 and selecting standard parallels 1/6th above or below the southern and northern extent, preserves both area and length for continental areas in mid latitudes oriented east-west. Custom map projection parameters can also minimize area and length error in non-ideal projections. Additionally, one must also use consistent vertical and horizontal datums for all geographic data. The generalized polygon for the Floridan aquifer system study area (306,247.59 km2) is used to provide quantitative examples of the effect of map projections on length and area with different projections and parameter choices. Use of improper map projection is one model construction problem easily avoided.

  13. Mapping groundwater quality distinguishing geogenic and anthropogenic contribution using NBL

    Science.gov (United States)

    Preziosi, Elisabetta; Ducci, Daniela; Condesso de Melo, Maria Teresa; Parrone, Daniele; Sellerino, Mariangela; Ghergo, Stefano; Oliveira, Joana; Ribeiro, Luis

    2015-04-01

    Groundwaters are threatened by anthropic activities and pollution is interesting a large number of aquifers worldwide. Qualitative and quantitative monitoring is required to assess the status and track its evolution in time and space especially where anthropic pressures are stronger. Up to now, groundwater quality mapping has been performed separately from the assessment of its natural status, i.e. the definition of the natural background level of a particular element in a particular area or groundwater body. The natural background level (NBL) of a substance or element allows to distinguish anthropogenic pollution from contamination of natural origin in a population of groundwater samples. NBLs are the result of different atmospheric, geological, chemical and biological interaction processes during groundwater infiltration and circulation. There is an increasing need for the water managers to have sound indications on good quality groundwater exploitation. Indeed the extension of a groundwater body is often very large, in the order of tens or hundreds of square km. How to select a proper location for good quality groundwater abstraction is often limited to a question of facility for drilling (access, roads, authorizations, etc.) or at the most related to quantitative aspects driven by geophysical exploration (the most promising from a transmissibility point of view). So how to give indications to the administrators and water managers about the exploitation of good quality drinking water? In the case of anthropic contamination, how to define which area is to be restored and to which threshold (e.g. background level) should the concentration be lowered through the restoration measures? In the framework of a common project between research institutions in Italy (funded by CNR) and Portugal (funded by FCT), our objective is to establish a methodology aiming at merging together 1) the evaluation of NBL and 2) the need to take into account the drinking water standards

  14. Groundwater Level Predictions Using Artificial Neural Networks

    Institute of Scientific and Technical Information of China (English)

    毛晓敏; 尚松浩; 刘翔

    2002-01-01

    The prediction of groundwater level is important for the use and management of groundwater resources. In this paper, the artificial neural networks (ANN) were used to predict groundwater level in the Dawu Aquifer of Zibo in Eastern China. The first step was an auto-correlation analysis of the groundwater level which showed that the monthly groundwater level was time dependent. An auto-regression type ANN (ARANN) model and a regression-auto-regression type ANN (RARANN) model using back-propagation algorithm were then used to predict the groundwater level. Monthly data from June 1988 to May 1998 was used for the network training and testing. The results show that the RARANN model is more reliable than the ARANN model, especially in the testing period, which indicates that the RARANN model can describe the relationship between the groundwater fluctuation and main factors that currently influence the groundwater level. The results suggest that the model is suitable for predicting groundwater level fluctuations in this area for similar conditions in the future.

  15. Groundwater vulnerability mapping of Qatar aquifers

    Science.gov (United States)

    Baalousha, Husam Musa

    2016-12-01

    Qatar is one of the most arid countries in the world with limited water resources. With little rainfall and no surface water, groundwater is the only natural source of fresh water in the country. Whilst the country relies mainly on desalination of seawater to secure water supply, groundwater has extensively been used for irrigation over the last three decades, which caused adverse environmental impact. Vulnerability assessment is a widely used tool for groundwater protection and land-use management. Aquifers in Qatar are carbonate with lots of fractures, depressions and cavities. Karst aquifers are generally more vulnerable to contamination than other aquifers as any anthropogenic-sourced contaminant, especially above a highly fractured zone, can infiltrate quickly into the aquifer and spread over a wide area. The vulnerability assessment method presented in this study is based on two approaches: DRASTIC and EPIK, within the framework of Geographical Information System (GIS). Results of this study show that DRASTIC vulnerability method suits Qatar hydrogeological settings more than EPIK. The produced vulnerability map using DRASTIC shows coastal and karst areas have the highest vulnerability class. The southern part of the country is located in the low vulnerability class due to occurrence of shale formation within aquifer media, which averts downward movement of contaminants.

  16. Map of Arsenic concentrations in groundwater of the United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The map graphic image at http://water.usgs.gov/GIS/browse/arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about...

  17. Data-Driven Techniques for Regional Groundwater Level Forecasts

    Science.gov (United States)

    Chang, F. J.; Chang, L. C.; Tsai, F. H.; Shen, H. Y.

    2015-12-01

    Data-Driven Techniques for Regional Groundwater Level Forecasts Fi-John Changa, Li-Chiu Changb, Fong He Tsaia, Hung-Yu Shenba Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC. b Department of Water Resources and Environmental Engineering, Tamkang University, New Taipei City 25137, Taiwan, ROC..Correspondence to: Fi-John Chang (email: changfj@ntu.edu.tw)The alluvial fan of the Zhuoshui River in Taiwan is a good natural recharge area of groundwater. However, the over extraction of groundwater occurs in the coastland results in serious land subsidence. Groundwater systems are heterogeneous with diverse temporal-spatial patterns, and it is very difficult to quantify their complex processes. Data-driven methods can effectively capture the spatial-temporal characteristics of input-output patterns at different scales for accurately imitating dynamic complex systems with less computational requirements. In this study, we implement various data-driven methods to suitably predict the regional groundwater level variations for making countermeasures in response to the land subsidence issue in the study area. We first establish the relationship between regional rainfall, streamflow as well as groundwater levels and then construct intelligent groundwater level prediction models for the basin based on the long-term (2000-2013) regional monthly data sets collected from the Zhuoshui River basin. We analyze the interaction between hydrological factors and groundwater level variations; apply the self-organizing map (SOM) to obtain the clustering results of the spatial-temporal groundwater level variations; and then apply the recurrent configuration of nonlinear autoregressive with exogenous inputs (R-NARX) to predicting the monthly groundwater levels. As a consequence, a regional intelligent groundwater level prediction model can be constructed based on the adaptive results of the SOM. Results demonstrate that the development

  18. Groundwater vulnerability to pollution mapping of Ranchi district using GIS.

    Science.gov (United States)

    Krishna, R; Iqbal, J; Gorai, A K; Pathak, G; Tuluri, F; Tchounwou, P B

    2015-12-01

    Groundwater pollution due to anthropogenic activities is one of the major environmental problems in urban and industrial areas. The present study demonstrates the integrated approach with GIS and DRASTIC model to derive a groundwater vulnerability to pollution map. The model considers the seven hydrogeological factors [Depth to water table (D), net recharge (R), aquifer media (A), soil media (S), topography or slope (T), impact of vadose zone (I) and hydraulic Conductivity(C)] for generating the groundwater vulnerability to pollution map. The model was applied for assessing the groundwater vulnerability to pollution in Ranchi district, Jharkhand, India. The model was validated by comparing the model output (vulnerability indices) with the observed nitrate concentrations in groundwater in the study area. The reason behind the selection of nitrate is that the major sources of nitrate in groundwater are anthropogenic in nature. Groundwater samples were collected from 30 wells/tube wells distributed in the study area. The samples were analyzed in the laboratory for measuring the nitrate concentrations in groundwater. A sensitivity analysis of the integrated model was performed to evaluate the influence of single parameters on groundwater vulnerability index. New weights were computed for each input parameters to understand the influence of individual hydrogeological factors in vulnerability indices in the study area. Aquifer vulnerability maps generated in this study can be used for environmental planning and groundwater management.

  19. Mapping groundwater quality in the Netherlands

    NARCIS (Netherlands)

    Pebesma, Edzer Jan

    2001-01-01

    Groundwater quality is the suitability of groundwater for a certain purpose (e.g. for human consumption), and is mostly determined by its chemical composition. Pollution from agricultural and industrial origin threatens the groundwater quality in the Netherlands. Locally, this pollution is me

  20. Surficial Geologic Map and Groundwater Resources of Woodstock, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG06-5 DeSimone, D., 2006,�Surficial Geologic Map and Groundwater Resources of Woodstock, Vermont: Vermont Geological Survey Open-File Report...

  1. GROUNDWATER QUALITY AND CONTAMINATION INDEX MAPPING IN CHANGCHUN CITY, CHINA

    Institute of Scientific and Technical Information of China (English)

    Hamadoun BOKAR; TANG Jie; LIN Nian-feng

    2004-01-01

    Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities.Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3- - Ca2+ and HCO3-of groundwater quality due to the increase of TDS, NO3- + NO2 (as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl- and NO3- ions and weak negative correlations between the depth of water table and Ca2+, 8O42-. C1- and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2 and Mn2+ ions.

  2. Extract relevant features from DEM for groundwater potential mapping

    Science.gov (United States)

    Liu, T.; Yan, H.; Zhai, L.

    2015-06-01

    Multi-criteria evaluation (MCE) method has been applied much in groundwater potential mapping researches. But when to data scarce areas, it will encounter lots of problems due to limited data. Digital Elevation Model (DEM) is the digital representations of the topography, and has many applications in various fields. Former researches had been approved that much information concerned to groundwater potential mapping (such as geological features, terrain features, hydrology features, etc.) can be extracted from DEM data. This made using DEM data for groundwater potential mapping is feasible. In this research, one of the most widely used and also easy to access data in GIS, DEM data was used to extract information for groundwater potential mapping in batter river basin in Alberta, Canada. First five determining factors for potential ground water mapping were put forward based on previous studies (lineaments and lineament density, drainage networks and its density, topographic wetness index (TWI), relief and convergence Index (CI)). Extraction methods of the five determining factors from DEM were put forward and thematic maps were produced accordingly. Cumulative effects matrix was used for weight assignment, a multi-criteria evaluation process was carried out by ArcGIS software to delineate the potential groundwater map. The final groundwater potential map was divided into five categories, viz., non-potential, poor, moderate, good, and excellent zones. Eventually, the success rate curve was drawn and the area under curve (AUC) was figured out for validation. Validation result showed that the success rate of the model was 79% and approved the method's feasibility. The method afforded a new way for researches on groundwater management in areas suffers from data scarcity, and also broaden the application area of DEM data.

  3. Spatial modeling for groundwater arsenic levels in North Carolina.

    Science.gov (United States)

    Kim, Dohyeong; Miranda, Marie Lynn; Tootoo, Joshua; Bradley, Phil; Gelfand, Alan E

    2011-06-01

    To examine environmental and geologic determinants of arsenic in groundwater, detailed geologic data were integrated with well water arsenic concentration data and well construction data for 471 private wells in Orange County, NC, via a geographic information system. For the statistical analysis, the geologic units were simplified into four generalized categories based on rock type and interpreted mode of deposition/emplacement. The geologic transitions from rocks of a primary pyroclastic origin to rocks of volcaniclastic sedimentary origin were designated as polylines. The data were fitted to a left-censored regression model to identify key determinants of arsenic levels in groundwater. A Bayesian spatial random effects model was then developed to capture any spatial patterns in groundwater arsenic residuals into model estimation. Statistical model results indicate (1) wells close to a transition zone or fault are more likely to contain detectible arsenic; (2) welded tuffs and hydrothermal quartz bodies are associated with relatively higher groundwater arsenic concentrations and even higher for those proximal to a pluton; and (3) wells of greater depth are more likely to contain elevated arsenic. This modeling effort informs policy intervention by creating three-dimensional maps of predicted arsenic levels in groundwater for any location and depth in the area.

  4. Risk assessment of groundwater level variability using variable Kriging methods

    Science.gov (United States)

    Spanoudaki, Katerina; Kampanis, Nikolaos A.

    2015-04-01

    Assessment of the water table level spatial variability in aquifers provides useful information regarding optimal groundwater management. This information becomes more important in basins where the water table level has fallen significantly. The spatial variability of the water table level in this work is estimated based on hydraulic head measured during the wet period of the hydrological year 2007-2008, in a sparsely monitored basin in Crete, Greece, which is of high socioeconomic and agricultural interest. Three Kriging-based methodologies are elaborated in Matlab environment to estimate the spatial variability of the water table level in the basin. The first methodology is based on the Ordinary Kriging approach, the second involves auxiliary information from a Digital Elevation Model in terms of Residual Kriging and the third methodology calculates the probability of the groundwater level to fall below a predefined minimum value that could cause significant problems in groundwater resources availability, by means of Indicator Kriging. The Box-Cox methodology is applied to normalize both the data and the residuals for improved prediction results. In addition, various classical variogram models are applied to determine the spatial dependence of the measurements. The Matérn model proves to be the optimal, which in combination with Kriging methodologies provides the most accurate cross validation estimations. Groundwater level and probability maps are constructed to examine the spatial variability of the groundwater level in the basin and the associated risk that certain locations exhibit regarding a predefined minimum value that has been set for the sustainability of the basin's groundwater resources. Acknowledgement The work presented in this paper has been funded by the Greek State Scholarships Foundation (IKY), Fellowships of Excellence for Postdoctoral Studies (Siemens Program), 'A simulation-optimization model for assessing the best practices for the

  5. Groundwater Level Status Report for 2005 Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    S.P. Allen; R.J. Koch

    2006-05-15

    The status of groundwater level monitoring at Los Alamos National Laboratory (LANL) in 2005 is provided in this report. The Groundwater Level Monitoring Project was instituted in 2005 to provide a framework for the collection and processing of quality controlled groundwater level data. This report summarizes groundwater level data for 137 monitoring wells, including 41 regional aquifer wells, 22 intermediate wells, and 74 alluvial wells. Pressure transducers were installed in 118 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well.

  6. 1:750,000-scale static ground-water levels of Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of static ground-water levels for the State of Nevada based on a 1974 ground-water map (Rush, 1974) published by the Nevada Department of...

  7. Hydrographs showing groundwater levels for selected wells in the Puyallup River watershed and vicinity, Pierce and King Counties, Washington

    Science.gov (United States)

    Lane, R.C.; Julich, R.J.; Justin, G.B.

    2013-01-01

    Hydrographs of groundwater levels for selected wells in and adjacent to the Puyallup River watershed in Pierce and King Counties, Washington, are presented using an interactive Web-based map of the study area to illustrate changes in groundwater levels on a monthly and seasonal basis. The interactive map displays well locations that link to the hydrographs, which in turn link to the U.S. Geological Survey National Water Information System, Groundwater Site Inventory System.

  8. Reliable groundwater levels: failures and lessons learned from modeling and monitoring studies

    Science.gov (United States)

    Van Lanen, Henny A. J.

    2017-04-01

    throughout the whole year. We simulated groundwater levels with a steady-state groundwater flow model with and without groundwater abstraction for the wet and dry season, i.e. considering a high (all streams included) and low drainage density (only major streams), respectively. Groundwater drawdown maps for the wet and dry season were compiled. Stakeholders (farmers, ecologists) were very concerned about the large drawdowns. After a while and discussions with the Water Supply Company and stakeholders, we realised that we had calculated unrealistic large drawdowns of the phreatic groundwater level for the dry season. We learnt that by applying a steady-state model we did not take into account the large volume of groundwater, which is released from the groundwater storage. The transient groundwater model that we developed then, showed that the volume of groundwater released from the storage per unit of time is significant and that the drawdown of the phreatic groundwater level by the end of the dry period is substantially smaller than the one simulated by the steady-state model. The results of the transient groundwater flow model agreed rather well with the pumping test that lasted the whole dry season.

  9. Groundwater Level Prediction using M5 Model Trees

    Science.gov (United States)

    Nalarajan, Nitha Ayinippully; Mohandas, C.

    2015-01-01

    Groundwater is an important resource, readily available and having high economic value and social benefit. Recently, it had been considered a dependable source of uncontaminated water. During the past two decades, increased rate of extraction and other greedy human actions have resulted in the groundwater crisis, both qualitatively and quantitatively. Under prevailing circumstances, the availability of predicted groundwater levels increase the importance of this valuable resource, as an aid in the planning of groundwater resources. For this purpose, data-driven prediction models are widely used in the present day world. M5 model tree (MT) is a popular soft computing method emerging as a promising method for numeric prediction, producing understandable models. The present study discusses the groundwater level predictions using MT employing only the historical groundwater levels from a groundwater monitoring well. The results showed that MT can be successively used for forecasting groundwater levels.

  10. Groundwater level status report for 2010, Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Richard J.; Schmeer, Sarah

    2011-03-01

    The status of groundwater level monitoring at Los Alamos National Laboratory in 2010 is provided in this report. This report summarizes groundwater level data for 194 monitoring wells, including 63 regional aquifer wells (including 10 regional/intermediate wells), 34 intermediate wells, 97 alluvial wells, and 12 water supply wells. Pressure transducers were installed in 162 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well. The report also summarizes the groundwater temperatures recorded in intermediate and regional aquifer monitoring wells and seasonal responses to snowmelt runoff observed in intermediate wells.

  11. Groundwater level status report for 2008, Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Richard J.; Schmeer, Sarah

    2009-03-01

    The status of groundwater level monitoring at Los Alamos National Laboratory in 2008 is provided in this report. This report summarizes groundwater level data for 179 monitoring wells, including 45 regional aquifer wells, 28 intermediate wells, 8 regional/intermediate wells, 106 alluvial wells, and 12 water supply wells. Pressure transducers were installed in 166 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well. The report also summarizes the groundwater temperatures recorded in intermediate and regional aquifer monitoring wells.

  12. Groundwater level status report for 2009, Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Richard J.; Schmeer, Sarah

    2010-03-01

    The status of groundwater level monitoring at Los Alamos National Laboratory in 2009 is provided in this report. This report summarizes groundwater level data for 179 monitoring wells, including 55 regional aquifer wells (including 11 regional/intermediate wells), 26 intermediate wells, 98 alluvial wells, and 12 water supply wells. Pressure transducers were installed in 161 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well. The report also summarizes the groundwater temperatures recorded in intermediate and regional aquifer monitoring wells.

  13. Hydrographs Showing Groundwater Level Changes for Selected Wells in the Chambers-Clover Creek Watershed and Vicinity, Pierce County, Washington

    Science.gov (United States)

    Justin, G.B.; Julich, R.; Payne, K.L.

    2009-01-01

    Selected groundwater level hydrographs for the Chambers-Clover Creek watershed (CCCW) and vicinity, Washington, are presented in an interactive web-based map to illustrate changes in groundwater levels in and near the CCCW on a monthly and seasonal basis. Hydrographs are linked to points corresponding to the well location on an interactive map of the study area. Groundwater level data and well information from Federal, State, and local agencies were obtained from the U.S. Geological Survey National Water Information System (NWIS), Groundwater Site Inventory (GWSI) System.

  14. Groundwater vulnerability mapping in Guadalajara aquifers system (Western Mexico)

    Science.gov (United States)

    Rizo-Decelis, L. David; Marín, Ana I.; Andreo, Bartolomé

    2016-04-01

    Groundwater vulnerability mapping is a practical tool to implement strategies for land-use planning and sustainable socioeconomic development coherent with groundwater protection. The objective of vulnerability mapping is to identify the most vulnerable zones of catchment areas and to provide criteria for protecting the groundwater used for drinking water supply. The delineation of protection zones in fractured aquifers is a challenging task due to the heterogeneity and anisotropy of hydraulic conductivities, which makes difficult prediction of groundwater flow organization and flow velocities. Different methods of intrinsic groundwater vulnerability mapping were applied in the Atemajac-Toluquilla groundwater body, an aquifers system that covers around 1300 km2. The aquifer supplies the 30% of urban water resources of the metropolitan area of Guadalajara (Mexico), where over 4.6 million people reside. Study area is located in a complex neotectonic active volcanic region in the Santiago River Basin (Western Mexico), which influences the aquifer system underneath the city. Previous works have defined the flow dynamics and identified the origin of recharge. In addition, the mixture of fresh groundwater with hydrothermal and polluted waters have been estimated. Two main aquifers compose the multilayer system. The upper aquifer is unconfined and consists of sediments and pyroclastic materials. Recharge of this aquifer comes from rainwater and ascending vertical fluids from the lower aquifer. The lower aquifer consists of fractured basalts of Pliocene age. Formerly, the main water source has been the upper unit, which is a porous and unconsolidated unit, which acts as a semi-isotropic aquifer. Intense groundwater usage has resulted in lowering the water table in the upper aquifer. Therefore, the current groundwater extraction is carried out from the deeper aquifer and underlying bedrock units, where fracture flow predominates. Pollution indicators have been reported in

  15. COMPARISON OF DETEMINISTIC INTERPOLATION METHODS FOR THE ESTIMATION OF GROUNDWATER LEVEL

    Directory of Open Access Journals (Sweden)

    Agnieszka Kamińska

    2014-10-01

    Full Text Available This paper compares two spatial interpolation techniques – Radial Basis Functions (RBF and Inverse Distance Weighting (IDW – with the goal of determining which method creates the best representation of reality for measured groundwater levels in catchment area. The study used the results of research and field observations from the year 2011, in Sosnowica (West Polesie. The data set consists of groundwater levels measured at 15 points in three series of tests. Surface generation was obtained for each method. The water prediction maps showed spatial variation in the groundwater level in the study area and they are quite different. RBF method resulted in a smoother map. The analysis of the methods of interpolation of analyzed data with the help of cross validation statistics and plots showed that Radial Basis Functions creates better representation of reality for measured groundwater levels.

  16. Prediction of monthly regional groundwater levels through hybrid soft-computing techniques

    Science.gov (United States)

    Chang, Fi-John; Chang, Li-Chiu; Huang, Chien-Wei; Kao, I.-Feng

    2016-10-01

    Groundwater systems are intrinsically heterogeneous with dynamic temporal-spatial patterns, which cause great difficulty in quantifying their complex processes, while reliable predictions of regional groundwater levels are commonly needed for managing water resources to ensure proper service of water demands within a region. In this study, we proposed a novel and flexible soft-computing technique that could effectively extract the complex high-dimensional input-output patterns of basin-wide groundwater-aquifer systems in an adaptive manner. The soft-computing models combined the Self Organized Map (SOM) and the Nonlinear Autoregressive with Exogenous Inputs (NARX) network for predicting monthly regional groundwater levels based on hydrologic forcing data. The SOM could effectively classify the temporal-spatial patterns of regional groundwater levels, the NARX could accurately predict the mean of regional groundwater levels for adjusting the selected SOM, the Kriging was used to interpolate the predictions of the adjusted SOM into finer grids of locations, and consequently the prediction of a monthly regional groundwater level map could be obtained. The Zhuoshui River basin in Taiwan was the study case, and its monthly data sets collected from 203 groundwater stations, 32 rainfall stations and 6 flow stations during 2000 and 2013 were used for modelling purpose. The results demonstrated that the hybrid SOM-NARX model could reliably and suitably predict monthly basin-wide groundwater levels with high correlations (R2 > 0.9 in both training and testing cases). The proposed methodology presents a milestone in modelling regional environmental issues and offers an insightful and promising way to predict monthly basin-wide groundwater levels, which is beneficial to authorities for sustainable water resources management.

  17. Response of the microbial community to seasonal groundwater level fluctuations in petroleum hydrocarbon-contaminated groundwater.

    Science.gov (United States)

    Zhou, Ai-xia; Zhang, Yu-ling; Dong, Tian-zi; Lin, Xue-yu; Su, Xiao-si

    2015-07-01

    The effects of seasonal groundwater level fluctuations on the contamination characteristics of total petroleum hydrocarbons (TPH) in soils, groundwater, and the microbial community were investigated at a typical petrochemical site in northern China. The measurements of groundwater and soil at different depths showed that significant TPH residue was present in the soil in this study area, especially in the vicinity of the pollution source, where TPH concentrations were up to 2600 mg kg(-1). The TPH concentration in the groundwater fluctuated seasonally, and the maximum variation was 0.8 mg L(-1). The highest TPH concentrations were detected in the silty clay layer and lied in the groundwater level fluctuation zones. The groundwater could reach previously contaminated areas in the soil, leading to higher groundwater TPH concentrations as TPH leaches into the groundwater. The coincident variation of the electron acceptors and TPH concentration with groundwater-table fluctuations affected the microbial communities in groundwater. The microbial community structure was significantly different between the wet and dry seasons. The canonical correspondence analysis (CCA) results showed that in the wet season, TPH, NO3(-), Fe(2+), TMn, S(2-), and HCO3(-) were the major factors correlating the microbial community. A significant increase in abundance of operational taxonomic unit J1 (97% similar to Dechloromonas aromatica sp.) was also observed in wet season conditions, indicating an intense denitrifying activity in the wet season environment. In the dry season, due to weak groundwater level fluctuations and low temperature of groundwater, the microbial activity was weak. But iron and sulfate-reducing were also detected in dry season at this site. As a whole, groundwater-table fluctuations would affect the distribution, transport, and biodegradation of the contaminants. These results may be valuable for the control and remediation of soil and groundwater pollution at this site

  18. Examining the Relationship between Drought Indices and Groundwater Levels

    OpenAIRE

    Navaratnam Leelaruban; Padmanabhan, G.; Peter Oduor

    2017-01-01

    Thorough characterization of the response of finite water resources to climatic factors is essential for water monitoring and management. In this study, groundwater level data from U.S. Geological Survey Ground-Water Climate Response Network wells were used to analyze the relationship between selected drought indices and groundwater level fluctuation. The drought episodes included in this study were selected using climate division level drought indices. Indices included the Palmer Drought Sev...

  19. GIS based Hydrogeological Vulnerability Mapping of Groundwater Resources in Jerash Area-Jordan

    Energy Technology Data Exchange (ETDEWEB)

    Hammouri, N [Department of Earth and Environmental Sciences, Faculty of Natural Resources and Environment, Hashemite University, Zarqa (Jordan); El-Naqa, A [Department of Water Management and Environment, Faculty of Natural Resources and Environment, Hashemite University, Zarqa (Jordan)

    2008-04-15

    This paper presents groundwater vulnerability mapping for Jerash area, north Jordan generated using EPIK and DRASTIC models. These models have been implemented using GIS to delineate groundwater protection zones and to suggest a protection plan to improve groundwater quality of the major springs and wells. Most of the groundwater resources in the study area are polluted and bacteria and nitrate levels are high. Different sources of groundwater pollution have been identified. Domestic wastewater is considered as a major source of pollution. Urban runoff, fertilizers from agricultural return flows and solid waste disposal appear to be secondary sources. The most relevant vulnerability class of EPIK map is very high which accounts for about 41 % of the total area. While in the DRASTIC vulnerability map, areas with high vulnerability were only about 23 % of the total area. There is a good correlation between vulnerability maps obtained from both models with microbiological and chemical pollution evidences. There is also a good agreement between the areas classified as highly vulnerable and those that have high levels of pollution. [Spanish] El estudio de vulnerabilidad de aguas subterraneas en la region de Yerash, Jordania fue obtenido mediante las metodologias de EPIK y DRASTIC. Se uso GIS para mapear las zonas protegidas y para sugerir un plan de proteccion para mejorar la calidad del agua subterranea en los principales manantiales y pozos. Los niveles de contaminacion bacteriana y de nitratos son elevados. El efluente domestico es la fuente mas importante de contaminacion; vienen en segundo lugar la precipitacion en zonas urbanas, los fertilizantes agricolas y los desechos solidos. En el mapa de EPIK, la vulnerabilidad extrema abarca hasta 41% del area total; en cambio, en el mapa de DRASTIC las areas de alta vulnerabilidad ocupan solo un 23% del area. La correlacion de los datos de contaminacion microbiana y quimica con ambos mapas der vulnerabilidad es buena

  20. Regional scale assessment of soil predictors of groundwater phosphate (P) levels in acidic sandy agricultural soils

    Science.gov (United States)

    Mabilde, Lisa

    2016-04-01

    Possible factors affecting the leaching of P to the groundwater in the Belgian sandy area are examined via regression analysis. The main objective is to investigate the dependency of phreatic groundwater phosphate concentrations (Flemish VMM monitoring net, monitoring period 2010-2013) on soil phosphate saturation degree (PSD) (1994-1997 mapping for Flemish Land Agency) (n = 1032). Additionally explored parameters include: depth distributions of Fe- and Al-oxides, sorbed P and phosphate sorption capacity (PSC) and soil pH. Interpolated data of these soil parameters in 3 depth layers (0-30, 30-60, 60-90 cm) were generated by ordinary kriging. Secondly, we assessed the significance of other edaphic factors potentially controlling the groundwater P: topsoil organic carbon content (OC %), soil clay content and fluctuation of the groundwater table. Overall, the mean PSD halved with each 30 cm depth layer (56 > 24 > 13 %) and was correlated to groundwater PO43- level. The statistical significance of the correlation with groundwater PO43- concentrations increased with depth layer. The poor correlation (R2 = 0.01) between PSD and groundwater phosphate concentration indicates that many factors, other than soil P status, control the transport of P from soil solution to the groundwater in Belgian sandy soils. A significant (PStructural equation modeling for example could be used to understand the practical importance of individual soil, management and hydrological potential predictors of groundwater PO4.

  1. Examining the Relationship between Drought Indices and Groundwater Levels

    Directory of Open Access Journals (Sweden)

    Navaratnam Leelaruban

    2017-01-01

    Full Text Available Thorough characterization of the response of finite water resources to climatic factors is essential for water monitoring and management. In this study, groundwater level data from U.S. Geological Survey Ground-Water Climate Response Network wells were used to analyze the relationship between selected drought indices and groundwater level fluctuation. The drought episodes included in this study were selected using climate division level drought indices. Indices included the Palmer Drought Severity Index, Palmer Hydrological Drought Index, and Standardized Precipitation Index (SPI-6, 9, 12, 24. Precipitation and the average temperature were also used. SPI-24 was found to correlate best with groundwater levels during drought. For 17 out of 32 wells, SPI-24 showed the best correlation amongst all of the indices. For 12 out of 32 wells, SPI-24 showed correlation coefficients of −0.6 or stronger; and for other wells, reasonably good correlation was demonstrated. The statistical significance of SPI-24 in predicting groundwater level was also tested. The correlation of average monthly groundwater levels with SPI-24 does not change much throughout the timeframe, for all of the studied wells. The duration of drought also had a significant correlation with the decline of groundwater levels. This study illustrates how drought indices can be used for a rapid assessment of drought impact on groundwater level.

  2. Maps showing ground-water units and withdrawal, Basin and Range Province, Texas

    Science.gov (United States)

    Brady, B.T.; Bedinger, M.S.; Mikels, John

    1984-01-01

    This report on ground-water units and withdrawal in the Basin and Range province of Texas (see index map) was prepared as part of a program of the U.S. Geological Survey to identify prospective regions for further study relative to isolation of high-level nuclear waste (Bedinger, Sargent, and Reed, 1984), utilizing program guidelines defined in Sargent and Bedinger (1984). Also included in this report are selected references on pertinent geologic and hydrologic studies of the region. Other map reports in this series contain detailed data on ground-water quality, surface distribution of selected rock types, tectonic conditions, areal geophysics, Pleistocene lakes and marshes, and mineral and energy resources.

  3. Groundwater surface mapping informs sources of catchment baseflow

    OpenAIRE

    J. F. Costelloe; T. J. Peterson; K. Halbert; A. W. Western; J. J. McDonnell

    2014-01-01

    Groundwater discharge is a major contributor to stream baseflow. Quantifying this flux is difficult, despite its considerable importance to water resource management and evaluation of the effects of groundwater extraction on streamflow. It is important to be able to differentiate between contributions to streamflow from regional groundwater discharge (more susceptible to groundwater extraction) compared to interflow processes (arguably less susceptible to groundwater ...

  4. Predicting of Groundwater Level Fluctuation Using ANN and ANFIS in Lailakh plain

    Directory of Open Access Journals (Sweden)

    Semko Rashidi

    2016-09-01

    Full Text Available Forecasting of groundwater level and its fluctuations is one of the essential measures(actions for integrated management planning of groundwater resources. Considering the nonlinear and complex relations that govern groundwater flow, designing a precise and simple model is considered as an inevitable necessity for simulating the groundwater resources behavior. Nowadays, the connoisseur systems such as Artificial Neural Networks (ANN and Adaptive Neuro Fuzzy Inference Systems (ANFIS have regarded as the useful and reliable tools for modeling the nonlinear mappings. The purpose of this study is developing the ANN and ANFIS models, to predict water table fluctuations of groundwater resources system in Lailakh Plain. The time-values of monthly average groundwater level, rainfall, temperature and evaporation were used to develop the proposed models. And, ANN and ANFIS dynamic, static andhybrid models were developed for predicting water table depths. Finally, the proposed models were compared and prioritized by the using of Analytical Hierarchy Process (AHP. The resultes of the research showed that the dynamic and static models were respectively the most accurate and careless groundwater table predicting models. The ANN dynamic model with three input parameters and MSE=0.776 and R=0.975, was the best model for the more accurately predicting of water table fluctuations in Lailakh plain.

  5. GROUNDWATER LEVEL ANALYSES OF PUNJAB, INDIA: A QUANTITATIVE APPROACH

    Directory of Open Access Journals (Sweden)

    Gopal Krishan

    2014-09-01

    Full Text Available Groundwater is considered to be the most vital for the livestock population. In Punjab, which is also the food basket of India, the groundwater level is declining at a rapid rate due to increase in the number of tube wells in the recent years and hence the groundwater abstraction has increased. In a recent study conducted for monitoring the groundwater level in Punjab, the water level data was monitored for the period 2006-2013 in Hoshiarpur, Jalandhar & Kapurthala districts of Bist-Doab; Faridkot, Firozepur, Ludhiana, Bhatinda & Patiala districts of Malwa region and Amritsar, Gurdaspur & Tarn Taran districts of Majha region of Punjab. The groundwater level data has shown that the maximum decline to the tune of 9.75 m was found in Patiala, followed by 8.57 m in Bhatinda and least decline of 3.13 m was found in Jalandhar during the period 2006-2013. The areas showing marked decline in water levels should practice artificial recharge. It is also essential to strengthen soil, water and groundwater institutions along with capacity building, training and education in specific areas like artificial recharge, groundwater modelling, watershed management, quality monitoring, and aquifer remediation on a continuous basis. Lastly, if immediate remedial measures are not taken to reverse the declining trend of water table, it would be difficult to sustain even the existing food grain production in the state, thereby, affecting the socio-economic condition of the farmers, specially the small and marginal farmers.

  6. DESIGN OF GROUNDWATER LEVEL MONITORING NETWORK WITH ORDINARY KRIGING

    Institute of Scientific and Technical Information of China (English)

    YANG Feng-guang; CAO Shu-you; LIU Xing-nian; YANG Ke-jun

    2008-01-01

    The primary network of groundwater level observation wells aims at realizing a regional groundwater management policy. It may give a regional picture of groundwater level with emphasis on the natural situation. Observation data from the primary network can be used to estimate the actual state of groundwater system. Since the cost of the installation and maintenance of a groundwater monitoring network is extremely high, the assessment of effectiveness of the network becomes very necessary. Groundwater level monitoring networks are the examples of discontinuous sampling on variables presenting spatial continuity and highly skewed frequency distributions. Anywhere in the aquifer, ordinary kriging provides estimates of the variable sampled and a standard error of the estimate. In this article, the average Kriging standard deviation was used as a criterion for the determination of network density,and the GIS-based approach was analysized. A case study of groundwater level network simulation in the Chaiwopu Basin, Xinjiang Uygur Autonomous Region, China, was presented. In the case study, the initial phreatic water observation wells were 18, a comparison of the three variogram parameters of the three defferent variogram models shows that the Gaussian model is the best. Finally, a network with 55 wells was constructed.

  7. 2012 Water Levels - Mojave River and the Morongo Groundwater Basins

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — During 2012, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo groundwater basins....

  8. Influence of groundwater level to slope displacement by geodetic method

    Science.gov (United States)

    Sadarviana, Vera; Abidin, Hasanuddin Z.; Santoso, Djoko; Kahar, Joenil; Achmad R., T.

    2016-05-01

    In the rainy season, Indonesia often experience landslide disasters. Rainwater flows on the surface of the ground and partially into the ground, and changing the groundwater level (GWL) which can cause pressure on surrounding material. Water becomes the main factor that triggered landslides because water causes pressure force on the slopes that are prone to move. With the geometric approach, slope material displacement vectors can be known, including the origin of the material pressure using dynamic mathematical model that considers GWL. The data was used 5 campaigns of GPS observations. The results are obtained the correlation coefficients between coefficient changes in groundwater levels to the vector position as a representative of correlation between the physical and geometric parameters. There is relatively strong because of the value of the average correlation coefficient is 0.91997. Further, curves between changes in groundwater levels and the displacement position shows that the greater the groundwater levels, the greater the material position shift occurs.

  9. Mapping the groundwater vulnerability for pollution at the pan African scale.

    Science.gov (United States)

    Ouedraogo, Issoufou; Defourny, Pierre; Vanclooster, Marnik

    2016-02-15

    We estimated vulnerability and pollution risk of groundwater at the pan-African scale. We therefore compiled the most recent continental scale information on soil, land use, geology, hydrogeology and climate in a Geographical Information System (GIS) at a resolution of 15 km × 15 km and at the scale of 1:60,000,000. The groundwater vulnerability map was constructed by means of the DRASTIC method. The map reveals that groundwater is highly vulnerable in Central and West Africa, where the watertable is very low. In addition, very low vulnerability is found in the large sedimentary basins of the African deserts where groundwater is situated in very deep aquifers. The groundwater pollution risk map is obtained by overlaying the DRASTIC vulnerability map with land use. The northern, central and western part of the African continent is dominated by high pollution risk classes and this is very strongly related to shallow groundwater systems and the development of agricultural activities. Subsequently, we performed a sensitivity analysis to evaluate the relative importance of each parameter on groundwater vulnerability and pollution risk. The sensitivity analysis indicated that the removal of the impact of vadose zone, the depth of the groundwater, the hydraulic conductivity and the net recharge causes a large variation in the mapped vulnerability and pollution risk. The mapping model was validated using nitrate concentration data of groundwater as a proxy of pollution risk. Pan-African concentration data were inferred from a meta-analysis of literature data. Results shows a good match between nitrate concentration and the groundwater pollution risk classes. The pan African assessment of groundwater vulnerability and pollution risk is expected to be of particular value for water policy and for designing groundwater resources management programs. We expect, however, that this assessment can be strongly improved when better pan African monitoring data related to groundwater

  10. Comparison of GRACE data and groundwater levels for the assessment of groundwater depletion in Jordan

    Science.gov (United States)

    Liesch, Tanja; Ohmer, Marc

    2016-09-01

    Gravity Recovery and Climate Experiment (GRACE) derived groundwater storage (GWS) data are compared with in-situ groundwater levels from five groundwater basins in Jordan, using newly gridded GRACE GRCTellus land data. It is shown that (1) the time series for GRACE-derived GWS data and in-situ groundwater-level measurements can be correlated, with R 2 from 0.55 to 0.74, (2) the correlation can be widely ascribed to the seasonal and trend component, since the detrended and deseasonalized time series show no significant correlation for most cases, implying that anomalous signals that deviate from the trend or seasonal behaviour are overlaid by noise, (3) estimates for water losses in Jordan based on the trend of GRACE data from 2003 to 2013 could be up to four times higher than previously assumed using estimated recharge and abstraction rates, and (4) a significant time-lagged cross correlation of the monthly changes in GRACE-derived groundwater storage and precipitation data was found, suggesting that the conventional method for deriving GWS from GRACE data probably does not account for the typical conditions in the study basins. Furthermore, a new method for deriving plausible specific yields from GRACE data and groundwater levels is demonstrated.

  11. Groundwater management based on monitoring of land subsidence and groundwater levels in the Kanto Groundwater Basin, Central Japan

    Science.gov (United States)

    Furuno, K.; Kagawa, A.; Kazaoka, O.; Kusuda, T.; Nirei, H.

    2015-11-01

    Over 40 million people live on and exploit the groundwater resources of the Kanto Plain. The Plain encompasses metropolitan Tokyo and much of Chiba Prefecture. Useable groundwater extends to the base of the Kanto Plain, some 2500 to 3000 m below sea level. Much of the Kanto Plain surface is at sea level. By the early 1970s, with increasing urbanization and industrial expansion, local overdraft of groundwater resources caused major ground subsidence and damage to commercial and residential structures as well as to local and regional infrastructure. Parts of the lowlands around Tokyo subsided to 4.0 m below sea level; particularly affected were the suburbs of Funabashi and Gyotoku in western Chiba. In the southern Kanto Plain, regulations, mainly by local government and later by regional agencies, led to installation of about 500 monitoring wells and almost 5000 bench marks by the 1990's. Many of them are still working with new monitoring system. Long-term monitoring is important. The monitoring systems are costly, but the resulting data provide continuous measurement of the "health" of the Kanto Groundwater Basin, and thus permit sustainable use of the groundwater resource.

  12. Comparison of selection methods to deduce natural background levels for groundwater units

    NARCIS (Netherlands)

    Griffioen, J.; Passier, H.F.; Klein, J.

    2008-01-01

    Establishment of natural background levels (NBL) for groundwater is commonly performed to serve as reference when assessing the contamination status of groundwater units. We compare various selection methods to establish NBLs using groundwater quality data forfour hydrogeologically different areas i

  13. Comparison of selection methods to deduce natural background levels for groundwater units

    NARCIS (Netherlands)

    Griffioen, J.; Passier, H.F.; Klein, J.

    2008-01-01

    Establishment of natural background levels (NBL) for groundwater is commonly performed to serve as reference when assessing the contamination status of groundwater units. We compare various selection methods to establish NBLs using groundwater quality data forfour hydrogeologically different areas

  14. Mapping of groundwater potential zones in the Musi basin using remote sensing data and GIS

    NARCIS (Netherlands)

    Ganapuram, Sreedhar; Vijaya Kumar, G.T.; Murali Krishna, I.V.; Kahya, Ercan; Demirel, M. Cüneyd

    2009-01-01

    The objective of this study is to explore the groundwater availability for agriculture in the Musi basin. Remote sensing data and geographic information system were used to locate potential zones for groundwater in the Musi basin. Various maps (i.e., base, hydrogeomorphological, geological, structur

  15. U.S. Geological Survey groundwater toolbox, a graphical and mapping interface for analysis of hydrologic data (version 1.0): user guide for estimation of base flow, runoff, and groundwater recharge from streamflow data

    Science.gov (United States)

    Barlow, Paul M.; Cunningham, William L.; Zhai, Tong; Gray, Mark

    2015-01-01

    This report is a user guide for the streamflow-hydrograph analysis methods provided with version 1.0 of the U.S. Geological Survey (USGS) Groundwater Toolbox computer program. These include six hydrograph-separation methods to determine the groundwater-discharge (base-flow) and surface-runoff components of streamflow—the Base-Flow Index (BFI; Standard and Modified), HYSEP (Fixed Interval, Sliding Interval, and Local Minimum), and PART methods—and the RORA recession-curve displacement method and associated RECESS program to estimate groundwater recharge from streamflow data. The Groundwater Toolbox is a customized interface built on the nonproprietary, open source MapWindow geographic information system software. The program provides graphing, mapping, and analysis capabilities in a Microsoft Windows computing environment. In addition to the four hydrograph-analysis methods, the Groundwater Toolbox allows for the retrieval of hydrologic time-series data (streamflow, groundwater levels, and precipitation) from the USGS National Water Information System, downloading of a suite of preprocessed geographic information system coverages and meteorological data from the National Oceanic and Atmospheric Administration National Climatic Data Center, and analysis of data with several preprocessing and postprocessing utilities. With its data retrieval and analysis tools, the Groundwater Toolbox provides methods to estimate many of the components of the water budget for a hydrologic basin, including precipitation; streamflow; base flow; runoff; groundwater recharge; and total, groundwater, and near-surface evapotranspiration.

  16. Mapping groundwater renewability using age data in the Baiyang alluvial fan, NW China

    Science.gov (United States)

    Huang, Tianming; Pang, Zhonghe; Li, Jie; Xiang, Yong; Zhao, Zhijiang

    2017-05-01

    Groundwater age has been used to map renewability of water resources within four groups: strong, partial, and rare renewability, and non-renewable. The Baiyang alluvial fan in NW China is a representative area for examining groundwater recharge from river infiltration and for mapping groundwater renewability, and it has been investigated using multiple isotopes and water chemistry. Systematic sampling included 52 samples for 2H and 18O analysis and 32 samples for 3H, 13C and 14C analysis. The δ13C compositions remain nearly constant throughout the basin (median -12.7‰) and indicate that carbonate dissolution does not alter 14C age. The initial 14C activity of 80 pmC, obtained by plotting 3H and 14C activity, was used to correct groundwater 14C age. The results show that areas closer to the river consist of younger groundwater ages; this suggests that river infiltration is the main recharge source to the shallow groundwater system. However, at distances far away from the river, groundwater ages become older, i.e., from modern water (less than 60 year) to pre-modern water (from 60 to 1,000 years) and paleowater (more than 1,000 yeas). The four classifications of groundwater renewability have been associated with different age ranges. The area of shallow groundwater with strong renewability accounts for 74% of the total study area. Because recharge condition (river infiltration) controls overall renewability, a groundwater renewability map is of significant importance to the management of groundwater exploitation of this area as well as other arid groundwater basins.

  17. Mapping groundwater renewability using age data in the Baiyang alluvial fan, NW China

    Science.gov (United States)

    Huang, Tianming; Pang, Zhonghe; Li, Jie; Xiang, Yong; Zhao, Zhijiang

    2017-01-01

    Groundwater age has been used to map renewability of water resources within four groups: strong, partial, and rare renewability, and non-renewable. The Baiyang alluvial fan in NW China is a representative area for examining groundwater recharge from river infiltration and for mapping groundwater renewability, and it has been investigated using multiple isotopes and water chemistry. Systematic sampling included 52 samples for 2H and 18O analysis and 32 samples for 3H, 13C and 14C analysis. The δ13C compositions remain nearly constant throughout the basin (median -12.7‰) and indicate that carbonate dissolution does not alter 14C age. The initial 14C activity of 80 pmC, obtained by plotting 3H and 14C activity, was used to correct groundwater 14C age. The results show that areas closer to the river consist of younger groundwater ages; this suggests that river infiltration is the main recharge source to the shallow groundwater system. However, at distances far away from the river, groundwater ages become older, i.e., from modern water (less than 60 year) to pre-modern water (from 60 to 1,000 years) and paleowater (more than 1,000 yeas). The four classifications of groundwater renewability have been associated with different age ranges. The area of shallow groundwater with strong renewability accounts for 74% of the total study area. Because recharge condition (river infiltration) controls overall renewability, a groundwater renewability map is of significant importance to the management of groundwater exploitation of this area as well as other arid groundwater basins.

  18. Optimisation of groundwater level monitoring networks using geostatistical modelling based on the Spartan family variogram and a genetic algorithm method

    Science.gov (United States)

    Parasyris, Antonios E.; Spanoudaki, Katerina; Kampanis, Nikolaos A.

    2016-04-01

    Groundwater level monitoring networks provide essential information for water resources management, especially in areas with significant groundwater exploitation for agricultural and domestic use. Given the high maintenance costs of these networks, development of tools, which can be used by regulators for efficient network design is essential. In this work, a monitoring network optimisation tool is presented. The network optimisation tool couples geostatistical modelling based on the Spartan family variogram with a genetic algorithm method and is applied to Mires basin in Crete, Greece, an area of high socioeconomic and agricultural interest, which suffers from groundwater overexploitation leading to a dramatic decrease of groundwater levels. The purpose of the optimisation tool is to determine which wells to exclude from the monitoring network because they add little or no beneficial information to groundwater level mapping of the area. Unlike previous relevant investigations, the network optimisation tool presented here uses Ordinary Kriging with the recently-established non-differentiable Spartan variogram for groundwater level mapping, which, based on a previous geostatistical study in the area leads to optimal groundwater level mapping. Seventy boreholes operate in the area for groundwater abstraction and water level monitoring. The Spartan variogram gives overall the most accurate groundwater level estimates followed closely by the power-law model. The geostatistical model is coupled to an integer genetic algorithm method programmed in MATLAB 2015a. The algorithm is used to find the set of wells whose removal leads to the minimum error between the original water level mapping using all the available wells in the network and the groundwater level mapping using the reduced well network (error is defined as the 2-norm of the difference between the original mapping matrix with 70 wells and the mapping matrix of the reduced well network). The solution to the

  19. Application and evaluation of kriging and cokriging methods on groundwater depth mapping.

    Science.gov (United States)

    Ahmadi, Seyed Hamid; Sedghamiz, Abbas

    2008-03-01

    Groundwater and water resources management play a key role in conserving the sustainable conditions in arid and semi-arid regions. Applying some techniques that can reveal the critical and hot conditions of water resources seem necessary. In this study, kriging and cokriging methods were evaluated for mapping the groundwater depth across a plain in which has experienced different climatic conditions (dry, wet, and normal) and consequently high variations in groundwater depth in a 12 year led in maximum, minimum, and mean depths. During this period groundwater depth has considerable fluctuations. Results obtained from geostatistical analysis showed that groundwater depth varies spatially in different climatic conditions. Furthermore, the calculated RMSE showed that cokriging approach was more accurate than kriging in mapping the groundwater depth though there was not a distinct difference. As a whole, kriging underestimated the real groundwater depth for dry, wet, and normal conditions by 5.5, 2.2, and 5.3%, while cokriging underestimations were 3.3, 2, and 2.2%, respectively; which showed the unbiasedness in estimations. Results implied that in the study area farming and cultivation in dry conditions needs more attention due to higher variability in groundwater depth in short distances compared to the other climate conditions. It is believed that geostatistical approaches are reliable tools for water resources managers and water authorities to allocate groundwater resources in different environmental conditions.

  20. Groundwater vulnerability and risk mapping using GIS, modeling and a fuzzy logic tool.

    Science.gov (United States)

    Nobre, R C M; Rotunno Filho, O C; Mansur, W J; Nobre, M M M; Cosenza, C A N

    2007-12-07

    A groundwater vulnerability and risk mapping assessment, based on a source-pathway-receptor approach, is presented for an urban coastal aquifer in northeastern Brazil. A modified version of the DRASTIC methodology was used to map the intrinsic and specific groundwater vulnerability of a 292 km(2) study area. A fuzzy hierarchy methodology was adopted to evaluate the potential contaminant source index, including diffuse and point sources. Numerical modeling was performed for delineation of well capture zones, using MODFLOW and MODPATH. The integration of these elements provided the mechanism to assess groundwater pollution risks and identify areas that must be prioritized in terms of groundwater monitoring and restriction on use. A groundwater quality index based on nitrate and chloride concentrations was calculated, which had a positive correlation with the specific vulnerability index.

  1. Groundwater quality and depletion in the Indo-Gangetic Basin mapped from in situ observations

    Science.gov (United States)

    MacDonald, A. M.; Bonsor, H. C.; Ahmed, K. M.; Burgess, W. G.; Basharat, M.; Calow, R. C.; Dixit, A.; Foster, S. S. D.; Gopal, K.; Lapworth, D. J.; Lark, R. M.; Moench, M.; Mukherjee, A.; Rao, M. S.; Shamsudduha, M.; Smith, L.; Taylor, R. G.; Tucker, J.; van Steenbergen, F.; Yadav, S. K.

    2016-10-01

    Groundwater abstraction from the transboundary Indo-Gangetic Basin comprises 25% of global groundwater withdrawals, sustaining agricultural productivity in Pakistan, India, Nepal and Bangladesh. Recent interpretations of satellite gravity data indicate that current abstraction is unsustainable, yet these large-scale interpretations lack the spatio-temporal resolution required to govern groundwater effectively. Here we report new evidence from high-resolution in situ records of groundwater levels, abstraction and groundwater quality, which reveal that sustainable groundwater supplies are constrained more by extensive contamination than depletion. We estimate the volume of groundwater to 200 m depth to be >20 times the combined annual flow of the Indus, Brahmaputra and Ganges, and show the water table has been stable or rising across 70% of the aquifer between 2000 and 2012. Groundwater levels are falling in the remaining 30%, amounting to a net annual depletion of 8.0 +/- 3.0 km3. Within 60% of the aquifer, access to potable groundwater is restricted by excessive salinity or arsenic. Recent groundwater depletion in northern India and Pakistan has occurred within a longer history of groundwater accumulation from extensive canal leakage. This basin-wide synthesis of in situ groundwater observations provides the spatial detail essential for policy development, and the historical context to help evaluate recent satellite gravity data.

  2. The impact of groundwater level on soil seed bank survival

    NARCIS (Netherlands)

    Bekker, RM; Oomes, MJM; Bakker, JP

    Seed longevity of plant species is an important topic in restoration management, and little is known about the effects of environmental conditions on seed survival and longevity under natural conditions. Therefore, the effect of groundwater level on the survival of seeds in the soil seed bank of a

  3. Groundwater levels in the Kabul Basin, Afghanistan, 2004-2013

    Science.gov (United States)

    Taher, Mohammad R.; Chornack, Michael P.; Mack, Thomas J.

    2014-01-01

    The Afghanistan Geological Survey, with technical assistance from the U.S. Geological Survey, established a network of wells to measure and monitor groundwater levels to assess seasonal, areal, and potentially climatic variations in groundwater characteristics in the Kabul Basin, Afghanistan, the most populous region in the country. Groundwater levels were monitored in 71 wells in the Kabul Basin, Afghanistan, starting as early as July 2004 and continuing to the present (2013). The monitoring network is made up exclusively of existing production wells; therefore, both static and dynamic water levels were recorded. Seventy wells are in unconsolidated sediments, and one well is in bedrock. Water levels were measured periodically, generally monthly, using electric tape water-level meters. Water levels in well 64 on the grounds of the Afghanistan Geological Survey building were measured more frequently. This report provides a 10-year compilation of groundwater levels in the Kabul Basin prepared in cooperation with the Afghanistan Geological Survey. Depths to water below land surface range from a minimum of 1.47 meters (m) in the Shomali subbasin to a maximum of 73.34 m in the Central Kabul subbasin. The Logar subbasin had the smallest range in depth to water below land surface (1.5 to 12.4 m), whereas the Central Kabul subbasin had the largest range (2.64 to 73.34 m). Seasonal water-level fluctuations can be estimated from the hydrographs in this report for wells that have depth-to-water measurements collected under static conditions. The seasonal water-level fluctuations range from less than 1 m to a little more than 7 m during the monitoring period. In general, the hydrographs for the Deh Sabz, Logar, Paghman and Upper Kabul, and Shomali subbasins show relatively little change in the water-level trend during the period of record, whereas hydrographs for the Central Kabul subbasin show water level decreases of several meters to about 25 m.

  4. Evaluation of bias associated with capture maps derived from nonlinear groundwater flow models

    Science.gov (United States)

    Nadler, Cara; Allander, Kip K.; Pohll, Greg; Morway, Eric; Naranjo, Ramon C.; Huntington, Justin

    2017-01-01

    The impact of groundwater withdrawal on surface water is a concern of water users and water managers, particularly in the arid western United States. Capture maps are useful tools to spatially assess the impact of groundwater pumping on water sources (e.g., streamflow depletion) and are being used more frequently for conjunctive management of surface water and groundwater. Capture maps have been derived using linear groundwater flow models and rely on the principle of superposition to demonstrate the effects of pumping in various locations on resources of interest. However, nonlinear models are often necessary to simulate head-dependent boundary conditions and unconfined aquifers. Capture maps developed using nonlinear models with the principle of superposition may over- or underestimate capture magnitude and spatial extent. This paper presents new methods for generating capture difference maps, which assess spatial effects of model nonlinearity on capture fraction sensitivity to pumping rate, and for calculating the bias associated with capture maps. The sensitivity of capture map bias to selected parameters related to model design and conceptualization for the arid western United States is explored. This study finds that the simulation of stream continuity, pumping rates, stream incision, well proximity to capture sources, aquifer hydraulic conductivity, and groundwater evapotranspiration extinction depth substantially affect capture map bias. Capture difference maps demonstrate that regions with large capture fraction differences are indicative of greater potential capture map bias. Understanding both spatial and temporal bias in capture maps derived from nonlinear groundwater flow models improves their utility and defensibility as conjunctive-use management tools.

  5. Mapping and analysis of the groundwater potability in the Lajeado municipality, Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Eduardo Strohschoen

    2009-04-01

    Full Text Available The groundwater sources spread in extensive areas and are relatively protected from pollution agents when compared to rivers and artificial reservoirs. These aspects, combined with low exploitation costs, provided a considerable growth in the groundwater use in the last decades. Groundwater became an important alternative source for public water supply in Brazil. This paper shows the georeferenced location of the groundwater exploitation points in the Lajeado, RS municipality and the potability analysis of this water. The groundwater exploitation in the study area is accomplished in the Serra Geral and Guarani aquifers and the exploitation points were identified in field campaigns using a GPS receiver and plotted over satellite imagery using remote sensing and geoprocessing techniques. The groundwater potability assessment was based on 100 samples for microbiological and physico-chemical analyses that included 78 samples of tubular wells and 22 of dug wells. Contour maps were generated for the analyzed parameters in the tubular wells, using geostatistics procedures. In this study, 362 tubular wells and 253 dug wells were studied. The results show that the dug wells are located mainly in rural areas and 77.27% of them aren’t suitable for human consumption due to high levels of contamination. The tubular wells are concentrated in urban areas and results revealed that 76.92% of them have water with suitable quality for the human consumption.

  6. Groundwater Level Status Report for Fiscal Year 2007 - Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Shannon P. Allen, Richard J. Koch

    2008-03-17

    The status of groundwater level monitoring at Los Alamos National Laboratory in Fiscal Year 2007 is provided in this report. The Groundwater Level Monitoring Project was instituted in 2005 to provide a framework for the collection and processing of quality controlled groundwater level data. This report summarizes groundwater level data for 166 monitoring wells, including 45 regional aquifer wells, 25 intermediate wells, and 96 alluvial wells, and 11 water supply wells. Pressure transducers were installed in 133 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well.

  7. Groundwater Level Status Report for Fiscal Year 2006 Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Shannon P. Allen, Richard J. Koch

    2007-03-30

    The status of groundwater level monitoring at Los Alamos National Laboratory in Fiscal Year 2006 is provided in this report. The Groundwater Level Monitoring Project was instituted in 2005 for providing a framework for the collection and processing of quality controlled groundwater level data. This report summarizes groundwater level data for 158 monitoring wells, including 43 regional aquifer wells, 23 intermediate wells, and 92 alluvial wells. Pressure transducers were installed in 132 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well.

  8. THE STUDY OF CHANGES IN ARDABIL PLAIN GROUNDWATER LEVEL USING GIS

    Directory of Open Access Journals (Sweden)

    Javad Zare Aghbolagh

    2016-03-01

    Full Text Available Uncontrolled exploitation of groundwater in many parts of the world has led to a sharp drop in groundwater levels. In this study, changes in Ardabil plain groundwater level were studied using geographic information system (GIS. For this purpose, the interpolation table method was used, the intrinsic data as table data of piezo metric wells was used. In order to implement the model, the Majol Geoestatical in geographic information system software was used. The data entered as regions into the geographic information system, and then done for the entire zoning area, due to zoning 8 models, the IDW, GPI, RBF, LPI, KO, KS, KU and EBK in geostatical extension were evaluated. The ordinary kriging method (KO with the lowest RMSE, was determined as the most accurate one, and finally, as the ultimate method for zoning and map providing for the changes in groundwater levels drop of the region. The results of classification showed that the biggest drop of about 40 meters was in the areas close to the southeastern parts of the study region and in other areas, little changes were observed, this rate of the change and decline in some parts of the desert like southern regions is very tangible and specified.

  9. Groundwater.

    Science.gov (United States)

    Braids, Olin C.; Gillies, Nola P.

    1978-01-01

    Presents a literature review of groundwater quality covering publications of 1977. This review includes: (1) sources of groundwater contamination; and (2) management of groundwater. A list of 59 references is also presented. (HM)

  10. Hydrogeology, ground-water use, and ground-water levels in the Mill Creek Valley near Evendale, Ohio

    Science.gov (United States)

    Schalk, Charles; Schumann, Thomas

    2002-01-01

    in 1955. During the time of the water-level survey (November 2000), ground water was being pumped from four locations in the lower aquifer, including three municipalities and one remediation site. Effects of pumping in those four areas were evident from the regional water-level data. Overall, the direction of ground-water flow in the lower aquifer is from northeast to southwest along the primary orientation of the Mill Creek Valley in the study area. Water levels in shallower surficial aquifers were mapped at local scales centered on GEAE. Examination of well logs indicated that these aquifers (called shallow and water-table) are discontinuous and, on a regional scale, few wells were completed in these aquifers. Water levels in the shallow aquifer indicated that flow was from northeast to southwest except in areas where pumping in the lower aquifer or the proximity of Mill Creek may have been affecting water levels in the shallow aquifer. Water levels in the water-table aquifer indicated flow toward Mill Creek from GEAE.

  11. Potential effects of existing and proposed groundwater withdrawals on water levels and natural groundwater discharge in Snake Valley and surrounding areas, Utah and Nevada

    Science.gov (United States)

    Masbruch, Melissa D.; Brooks, Lynette E.

    2017-04-14

    discharge, to future stresses at a point in the area represented by the model. In this way, these maps can be used as a tool to determine the source of water to, and potential effects at specific areas from, future well withdrawals.Downward trends in water levels measured in wells indicate that existing groundwater withdrawals in Snake Valley are affecting water levels. The numerical model simulates similar downward trends in water levels; simulated drawdowns in the model, however, are generally less than observed water-level declines. At the groundwater discharge sites of interest to the DOI agencies, simulated drawdowns from existing well withdrawals (projected into the future) range from 0 to about 50 feet. Following the addition of the proposed withdrawals, simulated drawdowns at some sites increase by 25 feet. Simulated drawdown resulting from the proposed withdrawals began in as few as 5 years after 2014 at several of the sites. At the groundwater discharge sites of interest to the DOI agencies, simulated capture of natural discharge resulting from the existing withdrawals ranged from 0 to 87 percent. Following the addition of the proposed withdrawals, simulated capture at several of the sites reached 100 percent, indicating that groundwater discharge at that site would cease. Simulated capture following the addition of the proposed withdrawals increased in as few as 5 years after 2014 at several of the sites.

  12. Remediation alternatives for low-level herbicide contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Conger, R.M. [BASF Corp., Geismar, LA (United States)

    1995-10-01

    In early 1995, an evaluation of alternatives for remediation of a shallow groundwater plume containing low-levels of an organic herbicide was conducted at BASF Corporation, a petrochemical facility located in Ascension Parish, Louisiana. The contaminated site is located on an undeveloped portion of property within 1/4 mile of the east bank of the Mississippi River near the community of Geismar. Environmental assessment data indicated that about two acres of the thirty acre site had been contaminated from past waste management practices with the herbicide bentazon. Shallow soils and groundwater between 5 to 15 feet in depth were affected. Maximum concentrations of bentazon in groundwater were less than seven parts per million. To identify potentially feasible remediation alternatives, the environmental assessment data, available research, and cost effectiveness were reviewed. After consideration of a preliminary list of alternatives, only two potentially feasible alternatives could be identified. Groundwater pumping, the most commonly used remediation alternative, followed by carbon adsorption treatment was identified as was a new innovative alternative known as vegetative transpiration. This alternative relies on the natural transpiration processes of vegetation to bioremediate organic contaminants. Advantages identified during screening suggest that the transpiration method could be the best remediation alternative to address both economic and environmental factors. An experiment to test critical factors of the vegetatived transpiration alternative with bentazon was recommended before a final decision on feasibility can be made.

  13. Index-based groundwater vulnerability mapping models using hydrogeological settings: A critical evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Prashant, E-mail: prashantkumar@csio.res.in [CSIR-Central Scientific Instruments Organisation, Chandigarh 160030 (India); Academy of Scientific and Innovative Research—CSIO, Chandigarh 160030 (India); Bansod, Baban K.S.; Debnath, Sanjit K. [CSIR-Central Scientific Instruments Organisation, Chandigarh 160030 (India); Academy of Scientific and Innovative Research—CSIO, Chandigarh 160030 (India); Thakur, Praveen Kumar [Indian Institute of Remote Sensing (ISRO), Dehradun 248001 (India); Ghanshyam, C. [CSIR-Central Scientific Instruments Organisation, Chandigarh 160030 (India); Academy of Scientific and Innovative Research—CSIO, Chandigarh 160030 (India)

    2015-02-15

    Groundwater vulnerability maps are useful for decision making in land use planning and water resource management. This paper reviews the various groundwater vulnerability assessment models developed across the world. Each model has been evaluated in terms of its pros and cons and the environmental conditions of its application. The paper further discusses the validation techniques used for the generated vulnerability maps by various models. Implicit challenges associated with the development of the groundwater vulnerability assessment models have also been identified with scientific considerations to the parameter relations and their selections. - Highlights: • Various index-based groundwater vulnerability assessment models have been discussed. • A comparative analysis of the models and its applicability in different hydrogeological settings has been discussed. • Research problems of underlying vulnerability assessment models are also reported in this review paper.

  14. Groundwater: Quality Levels and Human Exposure, SW Nigeria

    Directory of Open Access Journals (Sweden)

    Olusola Adeyemi

    2017-04-01

    Full Text Available Groundwater serves as a source of freshwater for agricultural, industrial and domestic purposes and it accounts for about 42%, 27% and 36% respectively. As it remains the only source of all-year-round supply of freshwater globally, it is of vital importance as regards water security, human survival and sustainable agriculture. The main goal of this study is to identify the main cause-effect relationship between human activities and the state of groundwater quality using a communication tool (the DPSIR Model; Drivers, Pressures, State, Impact and Response. A total of twenty-one samples were collected from ten peri-urban communities scattered across three conterminous Local Government Areas in Southwestern Nigeria. Each of the groundwater samples was tested for twelve parameters - total dissolved solids, pH, bicarbonate, chloride, lead, electrical conductivity, dissolved oxygen, nitrate, sulphate, magnesium and total suspended solids. The study revealed that the concentrations of DO and Pb were above threshold limits, while pH and N were just below the threshold and others elements were within acceptable limits based on Guidelines for Drinking Water Quality and Nigeria Standard for Drinking Water Quality. The study revealed that groundwater quality levels from the sampled wells are under pressure leading to reduction in the amount of freshwater availability. This is a first-order setback in achieving access to freshwater as a sustainable development goal across Less Developed Communities (LDCs globally. To combat this threat, there is the need for an integrated approach in response towards groundwater conservation and sustainability by all stakeholders.

  15. Separation of base flow from streamflow using groundwater levels - illustrated for the Pang catchment (UK)

    NARCIS (Netherlands)

    Peters, E.; Lanen, van H.A.J.

    2005-01-01

    A new filter to separate base flow from streamflow has developed that uses observed groundwater levels. To relate the base flow to the observed groundwater levels, a non-linear relation was used. This relation is suitable for unconfined aquifers with deep groundwater levels that do not respond to

  16. Separation of base flow from streamflow using groundwater levels - illustrated for the Pang catchment (UK)

    NARCIS (Netherlands)

    Peters, E.; Lanen, van H.A.J.

    2005-01-01

    A new filter to separate base flow from streamflow has developed that uses observed groundwater levels. To relate the base flow to the observed groundwater levels, a non-linear relation was used. This relation is suitable for unconfined aquifers with deep groundwater levels that do not respond to in

  17. Depletion mapping and constrained optimization to support managing groundwater extraction

    Science.gov (United States)

    Fienen, Michael N.; Bradbury, Kenneth R.; Kniffin, Maribeth; Barlow, Paul M.

    2017-01-01

    Groundwater models often serve as management tools to evaluate competing water uses including ecosystems, irrigated agriculture, industry, municipal supply, and others. Depletion potential mapping—showing the model-calculated potential impacts that wells have on stream baseflow - can form the basis for multiple potential management approaches in an oversubscribed basin. Specific management approaches can include scenarios proposed by stakeholders, systematic changes in well pumping based on depletion potential, and formal constrained optimization, which can be used to quantify the tradeoff between water use and stream baseflow. Variables such as the maximum amount of reduction allowed in each well and various groupings of wells using, for example, K-means clustering considering spatial proximity and depletion potential are considered. These approaches provide a potential starting point and guidance for resource managers and stakeholders to make decisions about groundwater management in a basin, spreading responsibility in different ways. We illustrate these approaches in the Little Plover River basin in central Wisconsin, United States—home to a rich agricultural tradition, with farmland and urban areas both in close proximity to a groundwater-dependent trout stream. Groundwater withdrawals have reduced baseflow supplying the Little Plover River below a legally established minimum. The techniques in this work were developed in response to engaged stakeholders with various interests and goals for the basin. They sought to develop a collaborative management plan at a watershed scale that restores the flow rate in the river in a manner that incorporates principles of shared governance and results in effective and minimally disruptive changes in groundwater extraction practices.

  18. A Comparison of Groundwater Storage Using GRACE Data, Groundwater Levels, and a Hydrological Model in Californias Central Valley

    Science.gov (United States)

    Kuss, Amber; Brandt, William; Randall, Joshua; Floyd, Bridget; Bourai, Abdelwahab; Newcomer, Michelle; Skiles, Joseph; Schmidt, Cindy

    2011-01-01

    The Gravity Recovery and Climate Experiment (GRACE) measures changes in total water storage (TWS) remotely, and may provide additional insight to the use of well-based data in California's agriculturally productive Central Valley region. Under current California law, well owners are not required to report groundwater extraction rates, making estimation of total groundwater extraction difficult. As a result, other groundwater change detection techniques may prove useful. From October 2002 to September 2009, GRACE was used to map changes in TWS for the three hydrological regions (the Sacramento River Basin, the San Joaquin River Basin, and the Tulare Lake Basin) encompassing the Central Valley aquifer. Net groundwater storage changes were calculated from the changes in TWS for each of the three hydrological regions and by incorporating estimates for additional components of the hydrological budget including precipitation, evapotranspiration, soil moisture, snow pack, and surface water storage. The calculated changes in groundwater storage were then compared to simulated values from the California Department of Water Resource's Central Valley Groundwater- Surface Water Simulation Model (C2VSIM) and their Water Data Library (WDL) Geographic Information System (GIS) change in storage tool. The results from the three methods were compared. Downscaling GRACE data into the 21 smaller Central Valley sub-regions included in C2VSIM was also evaluated. This work has the potential to improve California's groundwater resource management and use of existing hydrological models for the Central Valley.

  19. Artificial groundwater recharge zones mapping using remote sensing and GIS: a case study in Indian Punjab.

    Science.gov (United States)

    Singh, Amanpreet; Panda, S N; Kumar, K S; Sharma, Chandra Shekhar

    2013-07-01

    Artificial groundwater recharge plays a vital role in sustainable management of groundwater resources. The present study was carried out to identify the artificial groundwater recharge zones in Bist Doab basin of Indian Punjab using remote sensing and geographical information system (GIS) for augmenting groundwater resources. The study area has been facing severe water scarcity due to intensive agriculture for the past few years. The thematic layers considered in the present study are: geomorphology (2004), geology (2004), land use/land cover (2008), drainage density, slope, soil texture (2000), aquifer transmissivity, and specific yield. Different themes and related features were assigned proper weights based on their relative contribution to groundwater recharge. Normalized weights were computed using the Saaty's analytic hierarchy process. Thematic layers were integrated in ArcGIS for delineation of artificial groundwater recharge zones. The recharge map thus obtained was divided into four zones (poor, moderate, good, and very good) based on their influence to groundwater recharge. Results indicate that 15, 18, 37, and 30 % of the study area falls under "poor," "moderate," "good," and "very good" groundwater recharge zones, respectively. The highest recharge potential area is located towards western and parts of middle region because of high infiltration rates caused due to the distribution of flood plains, alluvial plain, and agricultural land. The least effective recharge potential is in the eastern and middle parts of the study area due to low infiltration rate. The results of the study can be used to formulate an efficient groundwater management plan for sustainable utilization of limited groundwater resources.

  20. Airborne and ground-based transient electromagnetic mapping of groundwater salinity in the Machile–Zambezi Basin, southwestern Zambia

    DEFF Research Database (Denmark)

    Chongo, Mkhuzo; Vest Christiansen, Anders; Tembo, Alice;

    2015-01-01

    is an efficient tool for mapping groundwater quality variations and has been used extensively to explore the Kalahari sediments, e.g., in Botswana and Namibia. Recently, airborne and groundbased mapping of groundwater salinity was conducted in the Machile–Zambezi Basin, southwestern Zambia, using the versatile...

  1. Reference springs in California for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set is a compilation of reference points representing springs in California that were used for the regional ground-water potential map...

  2. Reference springs in Nevada for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set is a compilation of reference points representing springs in Nevada that were used for the regional ground-water potential map by...

  3. Reference springs in Nevada for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set is a compilation of reference points representing springs in Nevada that were used for the regional ground-water potential map by...

  4. Temporal and spatial variability response of groundwater level to land use/land cover change in oases of arid areas

    Institute of Scientific and Technical Information of China (English)

    YAN Jinfeng; CHEN Xi; LUO Geping; GUO Quanjun

    2006-01-01

    This paper conducts a case study on the impacts of land use/cover change (LUCC) on the temporal and spatial variability of the groundwater level in an arid oasis in the Sangong River Watershed by using the geographical information system (GIS),remote sensing (RS) and geostatistical methods. The temporal and spatial variability of the groundwater level in the watershed in 1978, 1987 and 1998 is regressed by using thesemivariogram model and Kriging interpolation. The LUCC classification maps derived from the aerial images in 1978, Landsat TM image in 1987 and Landsat ETM image in 1998 are used to superpose and analyze the conversion relationship of LUCC types in the regions with different isograms of the groundwater depth. The results show that the change of groundwater recharge was not so significant in the whole oasis, but the temporal and spatial LUCC was significant either in the normal flow periods or in the high flow periods during the 20-year period from 1978 to 1998, and there was a close correlation between them. There is generally a moderate spatial correlation of groundwater level (33.4%),and the spatial autocorrelation distance is 17.78 km.The regions where the groundwater level is sharply changed are also the regions where the land resources are increasingly exploited, which include mainly the exploitation of farmlands, woodlands, and building, industrial and mining lands. The study reveals that the LUCC affects strongly the temporal and spatial variability of the groundwater level in the arid oasis. The study results are of direct and practical significance for rationally utilizing shallow groundwater resources and maintaining the stability of the arid oasis.

  5. Satellite mapping of areas evaporating river and groundwater flows

    Science.gov (United States)

    van Dijk, Albert I. J. M.; Guerschman, Juan Pablo; Warren, Garth A.

    2010-05-01

    The 500m resolution CSIRO MODIS reflectance scaling evapotranspiration product (CMRSET) was combined with a gridded rainfall product to determine where in the landscape evapotranspiration exceeds rainfall over longer time periods, and by implication, where lateral inflows of river or groundwater are received and evaporated. This procedure produces valuable information for hydrological applications, including the spatial distribution of water use, the temporal distribution, and the absolute magnitude of (net) evaporation across the landscape. Practical uses that have been tested in Australia include evaluating the realism of simulated water use components in river models, attributing apparent losses from river reaches to processes and spatial locations, and identifying river and groundwater dependent ecosystems. Satellite observed inundation patterns have been used to separate surface water from groundwater use. Higher resolution Landsat imagery has been used for image enhancement, allowing smaller irrigation and wetland areas to be detected. Satellite-based land use classification helps to separate agricultural from environmental water use. The information produced is used in the Australian Water Resources Assessment (AWRA) system under development by CSIRO and the Australian Bureau of Meteorology to underpin operational delivery of water resources information.

  6. Ground-water levels and directions of flow in Geauga County, Ohio, September 1994, and changes in ground-water levels, 1986-94

    Science.gov (United States)

    Jagucki, M.L.; Lesney, L.L.

    1995-01-01

    This report presents the results of a study by the U.S. Geological Survey, in cooperation with Geauga County Planning Commission and Board of County Commissioners, to determine directions of ground-water flow and to assess differences from 1986 to 1994 in ground-water levels in the glacial deposits and Pottsville Formation, Cuyahoga Group, and the Berea Sandstone. Water levels were measured in 219 wells in Geauga County, Ohio, in September 1994. Water levels measured in January and February 1986 in 88 of the 219 wells were used for comparison. Water-level maps constructed from measurements made in September 1994 to show that ground-water levels in the Pottsville Formation and the glacial deposits generally correspond to the land-surface configuration and that ground water flows from the uplands to adjacent streams and buried valleys. Ground-water flow in the Cuyahoga Group is generally downward from the Pottsville Formation to the Berea Sandstone. Directions of ground-water flow in the Berea Sandstone are toward outcrop areas at the north and east edges of Geauga County and toward sub-crops beneath buried glacial valley deposits in Chardon, Chester, Munson, and Russel Townships and along the west edge of the county. A comparison of water level measurements in 1986 and 1994 indicates that water levels declined in 70 percent of the measured wells and increased in 30 percent. The change in water levels from 1986 to 1994 ranged from an increase of 13.58 feet to a decrease of 29.25 feet. Thirty percent of all water-level changes were less than 1 foot in magnitude. In nearly 80 percent of the wells, water-level changes were within the range of plus or minus 5 feet. Among the wells for which two or more historical measurements were available, the 1994 water levels in 54 percent were outside the range of water-levels observed in previous studies (only 24 percent were greater than 1 foot outside of the previously-observed range). Water-level declines of greater than 10 feet

  7. Mapping irrigation potential from renewable groundwater in Africa - a quantitative hydrological approach

    Science.gov (United States)

    Altchenko, Y.; Villholth, K. G.

    2015-02-01

    Groundwater provides an important buffer to climate variability in Africa. Yet, groundwater irrigation contributes only a relatively small share of cultivated land, approximately 1% (about 2 × 106 hectares) as compared to 14% in Asia. While groundwater is over-exploited for irrigation in many parts in Asia, previous assessments indicate an underutilized potential in parts of Africa. As opposed to previous country-based estimates, this paper derives a continent-wide, distributed (0.5° spatial resolution) map of groundwater irrigation potential, indicated in terms of fractions of cropland potentially irrigable with renewable groundwater. The method builds on an annual groundwater balance approach using 41 years of hydrological data, allocating only that fraction of groundwater recharge that is in excess after satisfying other present human needs and environmental requirements, while disregarding socio-economic and physical constraints in access to the resource. Due to high uncertainty of groundwater environmental needs, three scenarios, leaving 30, 50 and 70% of recharge for the environment, were implemented. Current dominating crops and cropping rotations and associated irrigation requirements in a zonal approach were applied in order to convert recharge excess to potential irrigated cropland. Results show an inhomogeneously distributed groundwater irrigation potential across the continent, even within individual countries, mainly reflecting recharge patterns and presence or absence of cultivated cropland. Results further show that average annual renewable groundwater availability for irrigation ranges from 692 to 1644 km3 depending on scenario. The total area of cropland irrigable with renewable groundwater ranges from 44.6 to 105.3 × 106 ha, corresponding to 20.5 to 48.6% of the cropland over the continent. In particular, significant potential exists in the semi-arid Sahel and eastern African regions which could support poverty alleviation if developed

  8. Mapping organic contaminant plumes in groundwater using spontaneous potentials

    Science.gov (United States)

    Forte, Sarah

    Increased water demands have raised awareness of its importance. One of the challenges facing water resource management is dealing with contaminated groundwater; delineating, characterizing and remediating it. In the last decade, spontaneous potentials have been proposed as a method for delineating degrading organic contaminant plumes in groundwater. A hypothesis proposed that the redox potential gradient due to degradation of contaminants generated an electrical potential gradient that could be measured at the ground surface. This research was undertaken to better understand this phenomenon and find under what conditions it occurs. Spontaneous potentials are electrical potentials generated by three sources that act simultaneously: electrokinetic, thermoelectric and electrochemical sources. Over contaminant plumes electrochemical sources are those of interest. Thermoelectric sources are negligible unless in geothermal areas, but we hypothesized that electrokinetic potentials could be impacted by contaminants altering sediment surface properties. We built and calibrated a laboratory apparatus to make measurements that allowed us to calculate streaming current coupling coefficients. We tested sediment from hydrocarbon impacted sites with clean and hydrocarbon polluted groundwater and found a measurable though inconsistent effect. Moreover, numerical modelling was used to demonstrate that the impact of these changes on field measurements was negligible. Spontaneous potential surveys were conducted on two field sites with well characterized degrading hydrocarbon plumes in groundwater. We did not find a correlation between redox conditions and spontaneous potential, even after the electrical measurements were corrected for anthropogenic noise. In order to determine why the expected signal was not seen, we undertook numerical modelling based on coupled fluxes using two hypothesized types of current: redox and diffusion currents. The only scenarios that produced

  9. Levels and properties of map perception

    Directory of Open Access Journals (Sweden)

    Żyszkowska Wiesława

    2017-03-01

    Full Text Available Map perception consists of numerous processes of information processing, taking place almost simultaneously at different levels and stages which makes it conditioned by many factors. In the article, a review of processes related to the perception of a map as well as levels and properties of perception which impact its course and the nature of information obtained from a map is presented. The most important process constituting the basis of a map perception is a visual search (eye movement. However, as stated based on the studies, the process is individual depending on the purpose of map perception and it may be guided by its image (visual search guidance or by the knowledge of users (cognitive search guidance. Perception can take place according to various schemes – “local-to-global” or “global-to-local”, or in accordance with the guided search theory. Perception is divided into three processes: perceiving, distinguishing and identifying, which constitute the basis to interpret and understand a map. They are related to various degrees of intellectual involvement of the user and to various levels of questions concerning the relations between signs and their content. Identification involves referring a sign to its explanation in the legend. Interpretation means transformation of the initial information collected from the map into derivative information in which two basic types of understanding take place: deductive and inductive. Identification of geographical space objects on the map and the interpretation of its content constitute the basis to introduce information into memory structures. In the brain a resource of information is generated called geographic knowledge or spatial representation (mental map which may have a double nature – verbal or pictorial. An important feature of mental maps is organization of spatial information into hierarchical structures, e.g. grouping towns into regions as well as deformation of spatial

  10. Large scale mapping of groundwater resources using a highly integrated set of tools

    DEFF Research Database (Denmark)

    Søndergaard, Verner; Auken, Esben; Christiansen, Anders Vest

    platforms (e.g. SkyTEM) have made large-scale mapping attractive and affordable in the planning and administration of groundwater resources. The handling and optimized use of huge amounts of geophysical data covering large areas has also required a comprehensive database, where data can easily be stored......The aim of this abstract is to give a short description of the essential ideas of the Danish national strategy for large scale mapping of the groundwater resources.Emphasis will be put on a description of the advantages obtained by combining acquirement of spatially dense geophysical data covering...... large areas with information from an optimum number of new investigation boreholes, existing boreholes, logs and water samples to get an integrated and detailed description of the groundwater resources and their vulnerability.Development of more time efficient and airborne geophysical data acquisition...

  11. Future use of tritium in mapping pre-bomb groundwater volumes.

    Science.gov (United States)

    Eastoe, C J; Watts, C J; Ploughe, M; Wright, W E

    2012-01-01

    The tritium input to groundwater, represented as volume-weighted mean tritium concentrations in precipitation, has been close to constant in Tucson and Albuquerque since 1992, and the decrease in tritium concentrations at the tail end of the bomb tritium pulse has ceased. To determine the future usefulness of tritium measurements in southwestern North America, volume-weighted mean tritium levels in seasonal aggregate precipitation samples have been gathered from 26 sites. The averages range from 2 to 9 tritium units (TU). Tritium concentrations increase with site latitude, and possibly with distance from the coast and with site altitude, reflecting local ratios of combination of low-tritium moisture advected from the oceans with high-tritium moisture originating near the tropopause. Tritium used alone as a tool for mapping aquifer volumes containing only pre-bomb recharge to groundwater will become ambiguous when the tritium in precipitation at the end of the bomb tritium pulse decays to levels close to the analytical detection limit. At such a time, tritium in precipitation from the last one to two decades of the bomb pulse will become indistinguishable from pre-bomb recharge. The threshold of ambiguity has already arrived in coastal areas with a mean of 2 TU in precipitation and will follow in the next three decades throughout the study region. Where the mean tritium level is near 5 TU, the threshold will occur between 2025 and 2030, given a detection limit of 0.6 TU. Similar thresholds of ambiguity, with different local timing possible, apply globally. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

  12. Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia

    Science.gov (United States)

    Cui, Tao; Raiber, Matthias; Pagendam, Dan; Gilfedder, Mat; Rassam, David

    2017-08-01

    Understanding the response of groundwater levels in alluvial and sedimentary basin aquifers to climatic variability and human water-resource developments is a key step in many hydrogeological investigations. This study presents an analysis of groundwater response to climate variability from 2000 to 2012 in the Queensland part of the sedimentary Clarence-Moreton Basin, Australia. It contributes to the baseline hydrogeological understanding by identifying the primary groundwater flow pattern, water-level response to climate extremes, and the resulting dynamics of surface-water/groundwater interaction. Groundwater-level measurements from thousands of bores over several decades were analysed using Kriging and nonparametric trend analysis, together with a newly developed three-dimensional geological model. Groundwater-level contours suggest that groundwater flow in the shallow aquifers shows local variations in the close vicinity of streams, notwithstanding general conformance with topographic relief. The trend analysis reveals that climate variability can be quickly reflected in the shallow aquifers of the Clarence-Moreton Basin although the alluvial aquifers have a quicker rainfall response than the sedimentary bedrock formations. The Lockyer Valley alluvium represents the most sensitively responding alluvium in the area, with the highest declining (-0.7 m/year) and ascending (2.1 m/year) Sen's slope rates during and after the drought period, respectively. Different surface-water/groundwater interaction characteristics were observed in different catchments by studying groundwater-level fluctuations along hydrogeologic cross-sections. The findings of this study lay a foundation for future water-resource management in the study area.

  13. Application of vector autoregressive model for rainfall and groundwater level analysis

    Science.gov (United States)

    Keng, Chai Yoke; Shan, Fam Pei; Shimizu, Kunio; Imoto, Tomoaki; Lateh, Habibah; Peng, Koay Swee

    2017-08-01

    Groundwater is a crucial water supply for industrial, agricultural and residential use, hence it is important to understand groundwater system. Groundwater is a dynamic natural resource and can be recharged. The amount of recharge depends on the rate and duration of rainfall, as rainfall comprises an important component of the water cycle and is the prime source of groundwater recharge. This study applies Vector Autoregressive (VAR) model in the analysis of rainfall and groundwater level. The study area that is focused in the study is along the East-West Highway, Gerik-Jeli, Malaysia. The VAR model with optimum lag length 8, VAR(8) is selected to model the rainfall and groundwater level in the study area. Result of Granger causality test shows significant influence of rainfall to groundwater level. Impulse Response Function reveals that changes in rainfall significantly affect changes in groundwater level after some time lags. Moreover, Variance Decomposition reported that rainfall contributed to the forecast of the groundwater level. The VAR(8) model is validated by comparing the actual value with the in-sample forecasted value and the result is satisfied with all forecasted groundwater level values lies inside the confidence interval which indicate that the model is reliable. Furthermore, the closeness of both actual and forecasted groundwater level time series plots implies the high degree of accurateness of the estimated model.

  14. Efficient Calibration of Computationally Intensive Groundwater Models through Surrogate Modelling with Lower Levels of Fidelity

    Science.gov (United States)

    Razavi, S.; Anderson, D.; Martin, P.; MacMillan, G.; Tolson, B.; Gabriel, C.; Zhang, B.

    2012-12-01

    Many sophisticated groundwater models tend to be computationally intensive as they rigorously represent detailed scientific knowledge about the groundwater systems. Calibration (model inversion), which is a vital step of groundwater model development, can require hundreds or thousands of model evaluations (runs) for different sets of parameters and as such demand prohibitively large computational time and resources. One common strategy to circumvent this computational burden is surrogate modelling which is concerned with developing and utilizing fast-to-run surrogates of the original computationally intensive models (also called fine models). Surrogates can be either based on statistical and data-driven models such as kriging and neural networks or simplified physically-based models with lower fidelity to the original system (also called coarse models). Fidelity in this context refers to the degree of the realism of a simulation model. This research initially investigates different strategies for developing lower-fidelity surrogates of a fine groundwater model and their combinations. These strategies include coarsening the fine model, relaxing the numerical convergence criteria, and simplifying the model geological conceptualisation. Trade-offs between model efficiency and fidelity (accuracy) are of special interest. A methodological framework is developed for coordinating the original fine model with its lower-fidelity surrogates with the objective of efficiently calibrating the parameters of the original model. This framework is capable of mapping the original model parameters to the corresponding surrogate model parameters and also mapping the surrogate model response for the given parameters to the original model response. This framework is general in that it can be used with different optimization and/or uncertainty analysis techniques available for groundwater model calibration and parameter/predictive uncertainty assessment. A real-world computationally

  15. Spatial interpolation methods and geostatistics for mapping groundwater contamination in a coastal area.

    Science.gov (United States)

    Elumalai, Vetrimurugan; Brindha, K; Sithole, Bongani; Lakshmanan, Elango

    2017-04-01

    Mapping groundwater contaminants and identifying the sources are the initial steps in pollution control and mitigation. Due to the availability of different mapping methods and the large number of emerging pollutants, these methods need to be used together in decision making. The present study aims to map the contaminated areas in Richards Bay, South Africa and compare the results of ordinary kriging (OK) and inverse distance weighted (IDW) interpolation techniques. Statistical methods were also used for identifying contamination sources. Na-Cl groundwater type was dominant followed by Ca-Mg-Cl. Data analysis indicate that silicate weathering, ion exchange and fresh water-seawater mixing are the major geochemical processes controlling the presence of major ions in groundwater. Factor analysis also helped to confirm the results. Overlay analysis by OK and IDW gave different results. Areas where groundwater was unsuitable as a drinking source were 419 and 116 km(2) for OK and IDW, respectively. Such diverse results make decision making difficult, if only one method was to be used. Three highly contaminated zones within the study area were more accurately identified by OK. If large areas are identified as being contaminated such as by IDW in this study, the mitigation measures will be expensive. If these areas were underestimated, then even though management measures are taken, it will not be effective for a longer time. Use of multiple techniques like this study will help to avoid taking harsh decisions. Overall, the groundwater quality in this area was poor, and it is essential to identify alternate drinking water source or treat the groundwater before ingestion.

  16. Groundwater pollution risk mapping for the Eocene aquifer of the Oum Er-Rabia basin, Morocco

    Science.gov (United States)

    Ettazarini, Said

    2006-11-01

    Sustainable development requires the management and preservation of water resources indispensable for all human activities. When groundwater constitutes the main water resource, vulnerability maps therefore are an important tool for identifying zones of high pollution risk and taking preventive measures in potential pollution sites. The vulnerability assessment for the Eocene aquifer in the Moroccan basin of Oum Er-Rabia is based on the DRASTIC method that uses seven parameters summarizing climatic, geological, and hydrogeological conditions controlling the seepage of pollutant substances to groundwater. Vulnerability maps were produced by using GIS techniques and applying the “generic” and “agricultural” models according to the DRASTIC charter. Resulting maps revealed that the aquifer is highly vulnerable in the western part of the basin and areas being under high contamination risk are more extensive when the “agricultural” model was applied.

  17. Prediction maps of land subsidence caused by groundwater exploitation in Hanoi, Vietnam

    Directory of Open Access Journals (Sweden)

    Thinh Hong Phi

    2015-12-01

    Full Text Available The article presents study results of the land subsidence caused by groundwater exploitation in Hanoi, Vietnam. The study includes collection and analysis of data on geology, hydrology, soil properties and settlements observed at 10 monitoring stations as well as models of the time-dependent settlement. The calculated settlements are relatively close to actual monitoring data. The models were done for prediction of the land subsidence at 92 selected points by the finite element method. Prediction maps are made for prediction of the land subsidence in 2020 and 2030. Recommendations are proposed for potential zones of groundwater exploitation in Hanoi.

  18. Combining natural background levels (NBLs) assessment with indicator kriging analysis to improve groundwater quality data interpretation and management.

    Science.gov (United States)

    Ducci, Daniela; de Melo, M Teresa Condesso; Preziosi, Elisabetta; Sellerino, Mariangela; Parrone, Daniele; Ribeiro, Luis

    2016-11-01

    The natural background level (NBL) concept is revisited and combined with indicator kriging method to analyze the spatial distribution of groundwater quality within a groundwater body (GWB). The aim is to provide a methodology to easily identify areas with the same probability of exceeding a given threshold (which may be a groundwater quality criteria, standards, or recommended limits for selected properties and constituents). Three case studies with different hydrogeological settings and located in two countries (Portugal and Italy) are used to derive NBL using the preselection method and validate the proposed methodology illustrating its main advantages over conventional statistical water quality analysis. Indicator kriging analysis was used to create probability maps of the three potential groundwater contaminants. The results clearly indicate the areas within a groundwater body that are potentially contaminated because the concentrations exceed the drinking water standards or even the local NBL, and cannot be justified by geogenic origin. The combined methodology developed facilitates the management of groundwater quality because it allows for the spatial interpretation of NBL values.

  19. Geospatial modelling for groundwater quality mapping: a case study of Rupnagar district, Punjab, India

    Science.gov (United States)

    Sahoo, S.; Kaur, A.; Litoria, P.; Pateriya, B.

    2014-11-01

    Over period of time, the water usage and management is under stress for various reasons including pollution in both surface and subsurface. The groundwater quality decreases due to the solid waste from urban and industrial nodes, rapid use of insecticides and pesticides in agricultural practices. In this study, ground water quality maps for Rupnagar district of Punjab has been prepared using geospatial interpolation technique through Inverse Distance Weighted (IDW) approach. IDW technique has been used for major ground water quality parameters observed from the field samples like Arsenic, Hardness, pH, Iron, Fluoride, TDS, and Sulphate. To assess the ground water quality of the Rupnagar district, total 280 numbers of samples from various sources of tubewells for both pre and post monsoon have collected. Out of which, 80 to 113 samples found Iron with non potable limits ranging 0.3-1.1mg/l and 0.3-1.02mg/l according to BIS standard for both the seasons respectively. Chamkaur Sahib, Rupnagar, Morinda blocks have been found non potable limit of iron in both pre & post-monsoon. 11 to 52 samples in this region have sulphate with permissible limits in both the season ranging 200-400mg/l and 201-400mg/l. But arsenic had acceptable limit in both the season. Various parameters-wise ground water quality map is generated using the range values of drinking water quality to know the distribution of different parameters and diversification in the concentration of different elements. These maps are very much needful for human being to expand awareness among the people to maintain the Cleanness of water at their highest quality and purity levels to achieve a healthy life.

  20. Groundwater level deterioration issues and suggested solution for the water curtain cultivation area in South Korea

    Science.gov (United States)

    Kim, Yongcheol; Lee, Bongju; Ha, Kucheol; Yoon, Yunyeol; Moon, Sangho; Cho, Suyoung; Kim, Seongyun

    2013-04-01

    Protected water curtain cultivation system is an energy saving technique for winter season by splashing groundwater on the inner roof of the green house. But the issue is that the method results in groundwater level deterioration because it disposes the used groundwater to nearby stream. Reuse of the groundwater for water curtain cultivation is important Groundwater level, steam level, and groundwater usage rate are investigated at the five green house concentrated areas such as Cheongwon, Namyangju, Choongju, Namwon, Jinju. Groundwater usage rate is estimated using a ultrasonic flowmeter for a specific well and using the combination of pressure sensor and propeller type velocity counting equipment at a water disposal channel from November to April which is water curtain cultivating season. Groundwater usage rate ranges from 46.9m3/d to 108.0m3/d for a 10a greenhouse. Groundwater level change is strongly influenced by seasonal variation of rainfall and concentrated pumping activities in winter but the level is lower than stream level all year long resulting in all year around losing stream at Cheongwon, Namyangju, Jinju. At Nanwon, the stream is converted from losing one in winter to gaining one in summer. Groundwater level deterioration at concentrated water curtain cultivation area is found to be severe for some area where circulating water curtain cultivation system is need to be applied for groundwater restoration and sustainable cultivation in winter. Circulating water curtain cultivation system can restore the groundwater level by recharging the used groundwater through injection well and then pumping out from pumping well.

  1. Impacts of Future Climate Change and Baltic Sea Level Rise on Groundwater Recharge, Groundwater Levels, and Surface Leakage in the Hanko Aquifer in Southern Finland

    Directory of Open Access Journals (Sweden)

    Samrit Luoma

    2014-11-01

    Full Text Available The impact of climate change and Baltic Sea level rise on groundwater resources in a shallow, unconfined, low-lying coastal aquifer in Hanko, southern Finland, was assessed using the UZF1 model package coupled with the three-dimensional groundwater flow model MODFLOW to simulate flow from the unsaturated zone through the aquifer. The snow and PET models were used to calculate the surface water availability for infiltration from the precipitation data used in UZF1. Infiltration rate, flow in the unsaturated zone and groundwater recharge were then simulated using UZF1. The simulation data from climate and sea level rise scenarios were compared with present data. The results indicated changes in recharge pattern during 2071–2100, with recharge occurring earlier in winter and early spring. The seasonal impacts of climate change on groundwater recharge were more significant, with surface overflow resulting in flooding during winter and early spring and drought during summer. Rising sea level would cause some parts of the aquifer to be under sea level, compromising groundwater quality due to intrusion of sea water. This, together with increased groundwater recharge, would raise groundwater levels and consequently contribute more surface leakage and potential flooding in the low-lying aquifer.

  2. Spatial analyses of groundwater levels using universal kriging

    Indian Academy of Sciences (India)

    Kemal Sulhi Gundogdu; Ibrahim Guney

    2007-02-01

    For water levels, generally a non-stationary variable, the technique of universal kriging is applied in preference to ordinary kriging as the interpolation method. Each set of data in every sector can fit different empirical semivariogram models since they have different spatial structures. These models can be classified as circular, spherical, tetraspherical, pentaspherical, exponential, gaussian, rational quadratic, hole effect, K-bessel, J-bessel and stable. This study aims to determine which of these empirical semivariogram models will be best matched with the experimental models obtained from groundwater-table values collected from Mustafakemalpasa left bank irrigation scheme in 2002. The model having the least error was selected by comparing the observed water-table values with the values predicted by empirical semivariogram models. It was determined that the rational quadratic empirical semivariogram model is the best fitted model for the studied irrigation area.

  3. Confirmation of elevated arsenic levels in groundwater of Myanmar

    Science.gov (United States)

    van Geen, Alexander; Win, Kyi Htut; Zaw, Than; Naing, Win; Mey, Jacob L.; Mailloux, Brian

    2014-01-01

    Millions of villagers across South and Southeast Asia are exposed to toxic levels of arsenic (As) by drinking well water. In order to confirm field-kit results that Myanmar is also affected, a total of 55 wells were tested in the field in January 2013 and sampled for laboratory analysis across seven villages spanning a range of As contamination in the lower Ayeyarwady basin. Elevated concentrations of As (50–630 μg/L) were measured in wells up to 60 m deep and associated with high levels of Fe (up to 21 mg/L) and low concentrations of SO4 (<0.05 mg/L). Concentrations of As <10 μg/L were measured in some shallow (<30 m) grey sands and in both shallow and deep orange sands. These results indicate that the main mechanism of As release to groundwater in Myanmar is the reductive dissolution of Fe oxyhydroxides, as in the neighboring Bengal, Mekong, and Red River basins. Concentrations of As in groundwater of Myanmar are therefore unlikely to change rapidly over time and switching to existing low-As wells is a viable way of reducing exposure in the short term. However, only 17 of the 55 well owners interviewed correctly recalled the status of their well despite extensive testing in the region. A renewed effort is thus needed to test existing wells and new wells that continue to be installed and to communicate the health risks of exposure to As for infants, children, and adults. PMID:24530581

  4. Geomatics for Mapping of Groundwater Potential Zones in Northern Part of the United Arab Emiratis - Sharjah City

    Science.gov (United States)

    Al-Ruzouq, R.; Shanableh, A.; Merabtene, T.

    2015-04-01

    In United Arab Emirates (UAE) domestic water consumption has increased rapidly over the last decade. The increased demand for high-quality water, create an urgent need to evaluate the groundwater production of aquifers. The development of a reasonable model for groundwater potential is therefore crucial for future systematic developments, efficient management, and sustainable use of groundwater resources. The objective of this study is to map the groundwater potential zones in northern part of UAE and assess the contributing factors for exploration of potential groundwater resources. Remote sensing data and geographic information system will be used to locate potential zones for groundwater. Various maps (i.e., base, soil, geological, Hydro-geological, Geomorphologic Map, structural, drainage, slope, land use/land cover and average annual rainfall map) will be prepared based on geospatial techniques. The groundwater availability of the basin will qualitatively classified into different classes based on its hydro-geo-morphological conditions. The land use/land cover map will be also prepared for the different seasons using a digital classification technique with a ground truth based on field investigation.

  5. Delineating Groundwater Vulnerability and Protection Zone Mapping in Fractured Rock Masses: Focus on the DISCO Index

    Directory of Open Access Journals (Sweden)

    Helen Meerkhan

    2016-10-01

    Full Text Available Hard-rock catchments are considered to be source of valuable water resources for water supply to inhabitants and ecosystems. The present work aims to develop a groundwater vulnerability approach in the Caldas da Cavaca hydromineral system (Aguiar da Beira, Central Portugal in order to improve the hydrogeological conceptual site model. Different types of information were overlaid, generating several thematic maps to achieve an integrated framework of key sectors in the study site. Thus, a multi-technical approach was used, encompassing field and laboratory techniques, whereby different types of data were collected from fields such as geology, hydrogeology, applied geomorphology and geophysics and hydrogeomechanics, with the fundamental aim of applying the so-called DISCO index method. All of these techniques were successfully performed and an intrinsic groundwater vulnerability to contamination assessment, based on the multicriteria methodology of GOD-S, DRASTIC-Fm, SINTACS, SI and DISCO indexes, was delineated. Geographic Information Systems (GIS provided the basis on which to organize and integrate the databases and to produce all the thematic maps. This multi-technical approach highlights the importance of groundwater vulnerability to contamination mapping as a tool to support hydrogeological conceptualization, contributing to improving the decision-making process regarding water resources management and sustainability.

  6. Wavelet-entropy data pre-processing approach for ANN-based groundwater level modeling

    Science.gov (United States)

    Nourani, Vahid; Alami, Mohammad Taghi; Vousoughi, Farnaz Daneshvar

    2015-05-01

    Accurate and reliable groundwater level forecasting models can help ensure the sustainable use of a watershed's aquifers for urban and rural water supply. In this paper, a Self-Organizing-Map (SOM)-based clustering technique was used to identify spatially homogeneous clusters of groundwater level (GWL) data for a feed-forward neural network (FFNN) to model one and multi-step-ahead GWLs. The wavelet transform (WT) was also used to extract dynamic and multi-scale features of the non-stationary GWL, runoff and rainfall time series. The performance of the FFNN model was compared to the newly proposed combined WT-FFNN model and also the conventional linear forecasting method of ARIMAX (Auto Regressive Integrated Moving Average with exogenous input). GWL predictions were investigated under three different scenarios. The results indicated that the proposed FFNN model coupled with the SOM-based clustering method decreased the dimensionality of the input variables and consequently the complexity of the FFNN models. On the other hand, the application of the wavelet transform to GWL data increased the performance of the FFNN model up to 15.3% in average by revealing the dominant periods of the process.

  7. Strain Observation Affected by Groundwater-Level Change in Seismic Precursor Monitoring

    Science.gov (United States)

    Zhang, Lei; Cao, Daiyong; Zhang, Jingfa

    2017-03-01

    Groundwater extraction is one of the most typical disturbance factors for strain observation in seismic precursor monitoring. The statistic regression method is used to study based on the relation between the variation of strain and the groundwater level. The least square regression linear model is built between the annual variation of Sangzi groundwater level and the Xiaoxinzhuang strain data. Such model meets t test with significance level α = 0. 0 5, which confirms that groundwater-level change in each year affects strain measurement significantly and strain's trend variation is related to groundwater-level change. Consequently, a new correction method about strain data is put forward based on the groundwater-level annual variation to eliminate the trend change. Results indicate that the accumulated residual deformation causes the horizontal displacement and strain change, which is on account of that the amount of groundwater recharge is less than that of extraction around Xiaoxinzhuang cave, the phreatic surface continues to descend, and residual deformation accumulates and leads to local subsidence area. Therefore, the decline trend change of strain is related to groundwater-level change and is not seismic precursor.

  8. Automated system for monitoring groundwater levels at an experimental low-level waste disposal site

    Energy Technology Data Exchange (ETDEWEB)

    Newbold, J.D.; Bogle, M.A.

    1984-06-01

    One of the major problems with disposing of low-level solid wastes in the eastern United States is the potential for water-waste interactions and leachate migration. To monitor groundwater fluctuations and the frequency with which groundwater comes into contact with a group of experimental trenches, work at Oak Ridge National Laboratory's Engineered Test Facility (ETF) has employed a network of water level recorders that feed information from 15 on-site wells to a centralized data recording system. The purpose of this report is to describe the monitoring system being used and to document the computer programs that have been developed to process the data. Included in this report are data based on more than 2 years of water level information for ETF wells 1 through 12 and more than 6 months of data from all 15 wells. The data thus reflect both long-term trends as well as a large number of short-term responses to individual storm events. The system was designed to meet the specific needs of the ETF, but the hardware and computer routines have generic application to a variety of groundwater monitoring situations. 5 references.

  9. Effects of Soil and Water Conservation Measures on Groundwater Levels and Recharge

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2014-12-01

    Full Text Available Measures of soil and water conservation (SWC could affect the hydrological process. The impacts of typical measures on groundwater recharge, levels and flow were analyzed based on simulated rainfall experiments and a groundwater model. The three-dimensional finite-difference groundwater flow model (MODFLOW was calibrated and verified for bare slope, grassland and straw mulching scenarios based on the experiments. The results of the verification in groundwater balance, levels, runoff and flow field all showed that MODFLOW could be applied to study the impact of SWC measures on groundwater. Meanwhile, the results showed the recharge rate (α and specific yield of the three soil layers (Sy1, Sy2 and Sy3 were the most sensitive parameters to the change in the underlying surface. Then, the impacts of the SWC measures’ construction and destruction on the groundwater regime were studied. The results indicated the measures could strengthen groundwater recharge. The amounts of groundwater recharge, runoff and level were on the order of straw mulching > grassland > bare slope. When the underlying surface was converted from grass and mulching to bare slope, the recharge decreased by 42.2% and 39.1%. It was concluded that SWC measure construction would increase groundwater recharge and the measure destruction would decrease recharge.

  10. Machine learning algorithms for modeling groundwater level changes in agricultural regions of the U.S.

    Science.gov (United States)

    Sahoo, S.; Russo, T. A.; Elliott, J.; Foster, I.

    2017-05-01

    Climate, groundwater extraction, and surface water flows have complex nonlinear relationships with groundwater level in agricultural regions. To better understand the relative importance of each driver and predict groundwater level change, we develop a new ensemble modeling framework based on spectral analysis, machine learning, and uncertainty analysis, as an alternative to complex and computationally expensive physical models. We apply and evaluate this new approach in the context of two aquifer systems supporting agricultural production in the United States: the High Plains aquifer (HPA) and the Mississippi River Valley alluvial aquifer (MRVA). We select input data sets by using a combination of mutual information, genetic algorithms, and lag analysis, and then use the selected data sets in a Multilayer Perceptron network architecture to simulate seasonal groundwater level change. As expected, model results suggest that irrigation demand has the highest influence on groundwater level change for a majority of the wells. The subset of groundwater observations not used in model training or cross-validation correlates strongly (R > 0.8) with model results for 88 and 83% of the wells in the HPA and MRVA, respectively. In both aquifer systems, the error in the modeled cumulative groundwater level change during testing (2003-2012) was less than 2 m over a majority of the area. We conclude that our modeling framework can serve as an alternative approach to simulating groundwater level change and water availability, especially in regions where subsurface properties are unknown.

  11. Assessing the suitability of extreme learning machines (ELM for groundwater level prediction

    Directory of Open Access Journals (Sweden)

    Yadav Basant

    2017-03-01

    Full Text Available Fluctuation of groundwater levels around the world is an important theme in hydrological research. Rising water demand, faulty irrigation practices, mismanagement of soil and uncontrolled exploitation of aquifers are some of the reasons why groundwater levels are fluctuating. In order to effectively manage groundwater resources, it is important to have accurate readings and forecasts of groundwater levels. Due to the uncertain and complex nature of groundwater systems, the development of soft computing techniques (data-driven models in the field of hydrology has significant potential. This study employs two soft computing techniques, namely, extreme learning machine (ELM and support vector machine (SVM to forecast groundwater levels at two observation wells located in Canada. A monthly data set of eight years from 2006 to 2014 consisting of both hydrological and meteorological parameters (rainfall, temperature, evapotranspiration and groundwater level was used for the comparative study of the models. These variables were used in various combinations for univariate and multivariate analysis of the models. The study demonstrates that the proposed ELM model has better forecasting ability compared to the SVM model for monthly groundwater level forecasting.

  12. Data-driven behavioural characterization of dry-season groundwater-level variation in Maharashtra, India

    Indian Academy of Sciences (India)

    Rahul Gokhale; Milind Sohoni

    2015-06-01

    This paper looks at the crucial issue of dry-season groundwater-availability in the state of Maharashtra, India. We look at the two key hydro-climatological measurements which are used to implement ground-water policy in the state, viz., water levels in 5000+ observation wells across the state and aggregate rainfall data. We see that there is substantial variation in groundwater levels within and across the years in most wells. We argue that for a large number of these observation well locations, aggregate rainfall data is inadequate to model or to predict groundwater levels. For this, we use a novel random rainfall coefficient model for the purpose of modelling the effect of rainfall in a composite setting where extraction and changing land-use data is unknown. The observed high variance of this coefficient points to significant variations in groundwater levels, which may only be explained by unmeasured anthropogenic factors. Next, we see that the uncertainty in actual groundwater levels along with scarcity are two distinct features of groundwater availability and will elicit different behaviours from the typical user. Finally, we recommend that quantitative groundwater assessment protocols of the state should move to incorporating data from which extraction and land-use may be modelled. We believe this is one of the first studies where large spatio-temporal scale data gathered by state agencies have been analysed for scientific adequacy.

  13. Nitrate levels and the age of groundwater from the Upper Devonian sandstone aquifer in Fife, Scotland.

    Science.gov (United States)

    McNeill, G W; Anderson, J; Elliot, T

    2003-03-01

    The tritium concentrations in 13 groundwater samples from boreholes throughout the Upper Devonian sandstone aquifer of Fife have been measured. Due to atmospheric variations in tritium concentrations over the last century, this radioactive tracer can be used as a groundwater age indicator. In this study, the groundwater tritium concentrations have allowed for the area to be divided into three zones, and the variable chemistry of the groundwater samples, including the problem of recent elevated nitrate levels in the Fife Aquifer, has been interpreted in terms of their relative ages.

  14. Groundwater Level Fluctuation Forecasting in Birjand Aquifer Using Artificial Neural Network

    Science.gov (United States)

    Mirarabi, A.; Nakhaei, M.

    2009-04-01

    Artificial Neural Networks (ANNs) are being used increasingly to predict and forecast water resources variables such as groundwater levels. In this paper using artificial neural network three objective including determination of the influential parameters which impact fluctuation of groundwater level in birjand aquifer, investigation of the effect of temporal and spatial information by considering time series (9 years) and simulation of the fluctuation groundwater level in three selected piezometers are recognized. The reasonably good prediction of piezometric level simulated based on ANN using FNN_LM by selection of effective parameters and optimal time lag

  15. Groundwater contaminant plume maps and volumes, 100-K and 100-N Areas, Hanford Site, Washington

    Science.gov (United States)

    Johnson, Kenneth H.

    2016-09-27

    extents are shown graphically and in tabular form for comparison to previous estimates. Plume data also were interpolated to a finer grid (10 × 10 m) for some processing, particularly to estimate volumes of contaminated groundwater. However, hydrogeologic transport modeling was not considered for the interpolation. The compilation of plume extents for each contaminant also allowed estimates of overlap of the plumes or areas with more than one contaminant above regulatory standards.A mapping of saturated aquifer thickness also was derived across the 100-K and 100–N study area, based on the vertical difference between the groundwater level (water table) at the top and the altitude of the top of the Ringold Upper Mud geologic unit, considered the bottom of the uppermost unconfined aquifer. Saturated thickness was calculated for each cell in the finer (10 × 10 m) grid. The summation of the cells’ saturated thickness values within each polygon of plume regulatory exceedance provided an estimate of the total volume of contaminated aquifer, and the results also were checked using a SURFER® volumetric integration procedure. The total volume of contaminated groundwater in each plume was derived by multiplying the aquifer saturated thickness volume by a locally representative value of porosity (0.3).Estimates of the uncertainty of the plume delineation also are presented. “Upper limit” plume delineations were calculated for each contaminant using the same procedure as the “average” plume extent except with values at each well that are set at a 95-percent upper confidence limit around the log-normally transformed mean concentrations, based on the standard error for the distribution of the mean value in that well; “lower limit” plumes are calculated at a 5-percent confidence limit around the geometric mean. These upper- and lower-limit estimates are considered unrealistic because the statistics were increased or decreased at each well simultaneously and were not

  16. Machine Learning for Mapping Groundwater Salinity with Oil Well Log Data

    Science.gov (United States)

    Chang, W. H.; Shimabukuro, D.; Gillespie, J. M.; Stephens, M.

    2016-12-01

    An oil field may have thousands of wells with detailed petrophysical logs, and far fewer direct measurements of groundwater salinity. Can the former be used to extrapolate the latter into a detailed map of groundwater salinity? California Senate Bill 4, with its requirement to identify Underground Sources of Drinking Water, makes this a question worth answering. A well-known obstacle is that the basic petrophysical equations describe ideal scenarios ("clean wet sand") and even these equations contain many parameters that may vary with location and depth. Accounting for other common scenarios such as high-conductivity shaly sands or low-permeability diatomite (both characteristic of California's Central Valley) causes parameters to proliferate to the point where the model is underdetermined by the data. When parameters outnumber data points, however, is when machine learning methods are most advantageous. We present a method for modeling a generic oil field, where groundwater salinity and lithology are depth series parameters, and the constants in petrophysical equations are scalar parameters. The data are well log measurements (resistivity, porosity, spontaneous potential, and gamma ray) and a small number of direct groundwater salinity measurements. Embedded in the model are petrophysical equations that account for shaly sand and diatomite formations. As a proof of concept, we feed in well logs and salinity measurements from the Lost Hills Oil Field in Kern County, California, and show that with proper regularization and validation the model makes reasonable predictions of groundwater salinity despite the large number of parameters. The model is implemented using Tensorflow, which is an open-source software released by Google in November, 2015 that has been rapidly and widely adopted by machine learning researchers. The code will be made available on Github, and we encourage scrutiny and modification by machine learning researchers and hydrogeologists alike.

  17. Groundwater potentiality mapping of hard-rock terrain in arid regions using geospatial modelling: example from Wadi Feiran basin, South Sinai, Egypt

    Science.gov (United States)

    Arnous, Mohamed O.

    2016-09-01

    Identifying a good site for groundwater exploitation in hard-rock terrains is a challenging task. In Sinai, Egypt, groundwater is the only source of water for local inhabitants. Interpretation of satellite data for delineation of lithological units and weathered zones, and for mapping of lineament density and their trends, provides a valuable aid for the location of groundwater promising areas. Complex deformational histories of the wide range of lithological formations add to the difficulty. Groundwater prospect mapping is a systematic approach that considers the major controlling factors which influence the aquifer and quality of groundwater. The presented study aims to delineate, identify, model and map groundwater potential zones in arid South Sinai using remote sensing data and a geographic information system (GIS) to prepare various hydromorphogeological thematic maps such as maps of slope, drainage density, lithology, landforms, structural lineaments, rainfall intensity and plan curvature. The controlling-factor thematic maps are each allocated a fixed score and weight, computed by using a linear equation approach. Furthermore, each weighted thematic map is statistically computed to yield a groundwater potential zone map of the study area. The groundwater potential zones thus obtained were divided into five categories (very poor, poor, moderate, good and very good) and were validated using the relation between the zone and the spatial distribution of productive wells and of previous geophysical investigations from a literature review. The results show the groundwater potential zones in the study area, and create awareness for better planning and management of groundwater resources.

  18. Compositional cokriging for mapping the probability risk of groundwater contamination by nitrates.

    Science.gov (United States)

    Pardo-Igúzquiza, Eulogio; Chica-Olmo, Mario; Luque-Espinar, Juan A; Rodríguez-Galiano, Víctor

    2015-11-01

    Contamination by nitrates is an important cause of groundwater pollution and represents a potential risk to human health. Management decisions must be made using probability maps that assess the nitrate concentration potential of exceeding regulatory thresholds. However these maps are obtained with only a small number of sparse monitoring locations where the nitrate concentrations have been measured. It is therefore of great interest to have an efficient methodology for obtaining those probability maps. In this paper, we make use of the fact that the discrete probability density function is a compositional variable. The spatial discrete probability density function is estimated by compositional cokriging. There are several advantages in using this approach: (i) problems of classical indicator cokriging, like estimates outside the interval (0,1) and order relations, are avoided; (ii) secondary variables (e.g. aquifer parameters) can be included in the estimation of the probability maps; (iii) uncertainty maps of the probability maps can be obtained; (iv) finally there are modelling advantages because the variograms and cross-variograms of real variables that do not have the restrictions of indicator variograms and indicator cross-variograms. The methodology was applied to the Vega de Granada aquifer in Southern Spain and the advantages of the compositional cokriging approach were demonstrated.

  19. Fluctuations in groundwater levels related to regional and local withdrawals in the fractured-bedrock groundwater system in northern Wake County, North Carolina, March 2008-February 2009

    Science.gov (United States)

    Chapman, Melinda J.; Almanaseer, Naser; McClenney, Bryce; Hinton, Natalie

    2011-01-01

    February 2009. Correlation of groundwater-level distribution patterns with orientations of geologic structures obtained from surficial mapping, borehole geophysical measurements, and interpretation of fracture traces suggests two dominant trends striking north-south and N. 65 degrees W. A variation in overall response to groundwater withdrawals was noted in the continuous groundwater-level records for the monitored observation wells and dewatered private wells. The largest overall declines during the study period were observed in an observation well in which the water-level declined as much as 247 feet from mid-July through early August 2008, during a period of heavy usage. A private well had a water-level decline of about 94 feet during the same monitoring period. The large declines recorded in the observation well and the private well indicated a substantial temporary loss of storage in the fractured-bedrock aquifer near the wells, thus reducing the amount of water available to shallow wells in the area (those wells with total depths of about 300 feet), and resulting in temporary well failures until such time as the aquifer recovered.

  20. Isostatic gravity map of the Death Valley ground-water model area, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, D.A.; Blakely, R.J.; Morin, R.L.; Mankinen, E.A.

    2002-03-12

    Gravity investigations of the Death Valley ground-water model area are part of an interagency effort by the U.S. Geological Survey (USGS) and the U.S. Department of Energy (Interagency agreement DE-AI08-96NV11967) to help characterize the geology and hydrology of southwestern Nevada and parts of California. The Death Valley ground-water model is located between lat 35 degrees 00' and 38 degrees 15' N., and long 115 degrees and 118 degrees W. An isostatic gravity map of the Death Valley ground-water model was prepared from over 40,000 gravity stations, most of which are publicly available on a CD-ROM of gravity data of Nevada (Ponce, 1997). The map also includes gravity data recently collected by the U.S. Geological Survey (Mankinen and others, 1998; Morin and Blakely, 1999). A subset of these gravity data in the Nevada Test Site and vicinity were described in detail by Harris and others (1989) who included information on gravity meters used, dates of collection, sources, descriptions of base stations, plots of data, and digital and paper lists of principal facts. For display purposes only, gravity data within Yucca Flat were thinned by a factor of 10. The digital gravity data set was gridded at an interval of 400 m using a computer program (Webring, 1981) based on a minimum curvature algorithm by Briggs (1974). The resulting grid was then interpolated to a 200-m grid to minimize pixel size, and then it was color contoured.

  1. Sea-level rise and coastal groundwater inundation and shoaling at select sites in California, USA

    Science.gov (United States)

    Hoover, Daniel J.; Odigie, Kingsley; Swarzenski, Peter W.; Barnard, Patrick

    2016-01-01

    Study regionThe study region spans coastal California, USA, and focuses on three primary sites: Arcata, Stinson Beach, and Malibu Lagoon.Study focus1 m and 2 m sea-level rise (SLR) projections were used to assess vulnerability to SLR-driven groundwater emergence and shoaling at select low-lying, coastal sites in California. Separate and combined inundation scenarios for SLR and groundwater emergence were developed using digital elevation models of study site topography and groundwater surfaces constructed from well data or published groundwater level contours.New hydrological insights for the regionSLR impacts are a serious concern in coastal California which has a long (∼1800 km) and populous coastline. Information on the possible importance of SLR-driven groundwater inundation in California is limited. In this study, the potential for SLR-driven groundwater inundation at three sites (Arcata, Stinson Beach, and Malibu Lagoon) was investigated under 1 m and 2 m SLR scenarios. These sites provide insight into the vulnerability of Northern California coastal plains, coastal developments built on beach sand or sand spits, and developed areas around coastal lagoons associated with seasonal streams and berms. Northern California coastal plains with abundant shallow groundwater likely will see significant and widespread groundwater emergence, while impacts along the much drier central and southern California coast may be less severe due to the absence of shallow groundwater in many areas. Vulnerability analysis is hampered by the lack of data on shallow coastal aquifers, which commonly are not studied because they are not suitable for domestic or agricultural use. Shallow saline aquifers may be present in many areas along coastal California, which would dramatically increase vulnerability to SLR-driven groundwater emergence and shoaling. Improved understanding of the extent and response of California coastal aquifers to SLR will help in preparing for mitigation

  2. Study on the change rule of groundwater level and its impacts on vegetation at arid mining area

    Institute of Scientific and Technical Information of China (English)

    LEI Shao-gang; BIAN Zheng-fu; ZHANG Ri-chen; LI Lin

    2007-01-01

    The shallow groundwater in Shendong mining area was broken because of large-scale underground mining activities. Selecting 32201 working-face as research area,analyzed the change rule of groundwater level and aquifer thickness under mining impact with a large number of water level observation data. Then, the impacts of groundwater level change on vegetation were analyzed by the relationship theory of arid area groundwater and vegetation. The results show that the aquifer structure and the water condition of supply flow and drainage are changed by the water proof mining. The groundwater level recovere only a little compared with the original groundwater level in two years. But the great change of groundwater level do not have notable influences on vegetation of this mining area, and further study indicates that there are certain conditions where groundwater level change impacted on vegetation. When the influence of groundwater level change was evaluated, the plant ecological water level, warning water level and spatial distribution character of original groundwater and mining-impacted groundwater-level change should be integrated.

  3. Groundwater level responses to precipitation variability in Mediterranean insular aquifers

    Science.gov (United States)

    Lorenzo-Lacruz, Jorge; Garcia, Celso; Morán-Tejeda, Enrique

    2017-09-01

    Groundwater is one of the largest and most important sources of fresh water on many regions under Mediterranean climate conditions, which are exposed to large precipitation variability that includes frequent meteorological drought episodes, and present high evapotranspiration rates and water demand during the dry season. The dependence on groundwater increases in those areas with predominant permeable lithologies, contributing to aquifer recharge and the abundance of ephemeral streams. The increasing pressure of tourism on water resources in many Mediterranean coastal areas, and uncertainty related to future precipitation and water availability, make it urgent to understand the spatio-temporal response of groundwater bodies to precipitation variability, if sustainable use of the resource is to be achieved. We present an assessment of the response of aquifers to precipitation variability based on correlations between the Standardized Precipitation Index (SPI) at various time scales and the Standardized Groundwater Index (SGI) across a Mediterranean island. We detected three main responses of aquifers to accumulated precipitation anomalies: (i) at short time scales of the SPI (24 months). The differing responses were mainly explained by differences in lithology and the percentage of highly permeable rock strata in the aquifer recharge areas. We also identified differences in the months and seasons when aquifer storages are more dependent on precipitation; these were related to climate seasonality and the degree of aquifer exploitation or underground water extraction. The recharge of some aquifers, especially in mountainous areas, is related to precipitation variability within a limited spatial extent, whereas for aquifers located in the plains, precipitation variability influence much larger areas; the topography and geological structure of the island explain these differences. Results indicate large spatial variability in the response of aquifers to precipitation in

  4. Integrated mapping of groundwater drought risk in the Southern African Development Community (SADC) region

    CSIR Research Space (South Africa)

    Villholth, KG

    2013-06-01

    Full Text Available Groundwater drought denotes the condition and hazard during a prolonged meteorological drought when groundwater resources decline and become unavailable or inaccessible for human use. Groundwater drought risk refers to the combined physical risk...

  5. Mapping of groundwater potential zones in Salem Chalk Hills, Tamil Nadu, India, using remote sensing and GIS techniques.

    Science.gov (United States)

    Thilagavathi, N; Subramani, T; Suresh, M; Karunanidhi, D

    2015-04-01

    This study proposes to introduce the remote sensing and geographic information system (GIS) techniques in mapping the groundwater potential zones. Remote sensing and GIS techniques have been used to map the groundwater potential zones in Salem Chalk Hills, Tamil Nadu, India. Charnockites and fissile hornblende biotite gneiss are the major rock types in this region. Dunites and peridodites are the ultramafic rocks which cut across the foliation planes of the gneisses and are highly weathered. It comprises magnesite and chromite deposits which are excavated by five mining companies by adopting bench mining. The thickness of weathered and fracture zone varies from 2.2 to 50 m in gneissic formation and 5.8 to 55 m in charnockite. At the contacts of gneiss and charnockite, the thickness ranges from 9.0 to 90.8 m favoring good groundwater potential. The mine lease area is underlined by fractured and sheared hornblende biotite gneiss where groundwater potential is good. Water catchment tanks in this area of 5 km radius are small to moderate in size and are only seasonal. They remain dry during summer seasons. As perennial water resources are remote, the domestic and agricultural activities in this region depend mainly upon the groundwater resources. The mines are located in gently slope area, and accumulation of water is not observed except in mine pits even during the monsoon period. Therefore, it is essential to map the groundwater potential zones for proper management of the aquifer system. Satellite imageries were also used to extract lineaments, hydrogeomorphic landforms, drainage patterns, and land use, which are the major controlling factors for the occurrence of groundwater. Various thematic layers pertaining to groundwater existence such as geology, geomorphology, land use/land cover, lineament, lineament density, drainage, drainage density, slope, and soil were generated using GIS tools. By integrating all the above thematic layers based on the ranks and

  6. A comparative assessment of GIS-based data mining models and a novel ensemble model in groundwater well potential mapping

    Science.gov (United States)

    Naghibi, Seyed Amir; Moghaddam, Davood Davoodi; Kalantar, Bahareh; Pradhan, Biswajeet; Kisi, Ozgur

    2017-05-01

    In recent years, application of ensemble models has been increased tremendously in various types of natural hazard assessment such as landslides and floods. However, application of this kind of robust models in groundwater potential mapping is relatively new. This study applied four data mining algorithms including AdaBoost, Bagging, generalized additive model (GAM), and Naive Bayes (NB) models to map groundwater potential. Then, a novel frequency ratio data mining ensemble model (FREM) was introduced and evaluated. For this purpose, eleven groundwater conditioning factors (GCFs), including altitude, slope aspect, slope angle, plan curvature, stream power index (SPI), river density, distance from rivers, topographic wetness index (TWI), land use, normalized difference vegetation index (NDVI), and lithology were mapped. About 281 well locations with high potential were selected. Wells were randomly partitioned into two classes for training the models (70% or 197) and validating them (30% or 84). AdaBoost, Bagging, GAM, and NB algorithms were employed to get groundwater potential maps (GPMs). The GPMs were categorized into potential classes using natural break method of classification scheme. In the next stage, frequency ratio (FR) value was calculated for the output of the four aforementioned models and were summed, and finally a GPM was produced using FREM. For validating the models, area under receiver operating characteristics (ROC) curve was calculated. The ROC curve for prediction dataset was 94.8, 93.5, 92.6, 92.0, and 84.4% for FREM, Bagging, AdaBoost, GAM, and NB models, respectively. The results indicated that FREM had the best performance among all the models. The better performance of the FREM model could be related to reduction of over fitting and possible errors. Other models such as AdaBoost, Bagging, GAM, and NB also produced acceptable performance in groundwater modelling. The GPMs produced in the current study may facilitate groundwater exploitation

  7. Health risk estimates for groundwater and soil contamination in the Slovak Republic: a convenient tool for identification and mapping of risk areas.

    Science.gov (United States)

    Fajčíková, K; Cvečková, V; Stewart, A; Rapant, S

    2014-10-01

    We undertook a quantitative estimation of health risks to residents living in the Slovak Republic and exposed to contaminated groundwater (ingestion by adult population) and/or soils (ingestion by adult and child population). Potential risk areas were mapped to give a visual presentation at basic administrative units of the country (municipalities, districts, regions) for easy discussion with policy and decision-makers. The health risk estimates were calculated by US EPA methods, applying threshold values for chronic risk and non-threshold values for cancer risk. The potential health risk was evaluated for As, Ba, Cd, Cu, F, Hg, Mn, NO3 (-), Pb, Sb, Se and Zn for groundwater and As, B, Ba, Be, Cd, Cu, F, Hg, Mn, Mo, Ni, Pb, Sb, Se and Zn for soils. An increased health risk was identified mainly in historical mining areas highly contaminated by geogenic-anthropogenic sources (ore deposit occurrence, mining, metallurgy). Arsenic and antimony were the most significant elements in relation to health risks from groundwater and soil contamination in the Slovak Republic contributing a significant part of total chronic risk levels. Health risk estimation for soil contamination has highlighted the significance of exposure through soil ingestion in children. Increased cancer risks from groundwater and soil contamination by arsenic were noted in several municipalities and districts throughout the country in areas with significantly high arsenic levels in the environment. This approach to health risk estimations and visualization represents a fast, clear and convenient tool for delineation of risk areas at national and local levels.

  8. Isotope techniques for the research of groundwater in the potential site of China’s high-level waste repository

    Institute of Scientific and Technical Information of China (English)

    郭永海; 刘淑芬; 杨天笑; 姜桂林

    2001-01-01

    Using the isotope techniques, the groundwater origin, evolution and circulation in the potential site of China’s high-level waste repository are studied. The results indicate that both shallow groundwaters and deep groundwaters in the site area are of meteoric origin. The shallow groundwaters are mainly recharged by modern and local precipitation, and the deep groundwaters are originated from regional precipitation at higher elevation, or may be from the precipitation during the geological history period with lower temperature. Through the study we can also understand that the deep underground is a very low-permeability system where the groundwater flow-rates are very low.

  9. A coupled groundwater-flow-modelling and vulnerability-mapping methodology for karstic terrain management

    Science.gov (United States)

    Kavouri, Konstantina P.; Karatzas, George P.; Plagnes, Valérie

    2017-02-01

    A coupled groundwater-flow-modelling and vulnerability-mapping methodology for the management of karst aquifers with spatial variability is developed. The methodology takes into consideration the duality of flow and recharge in karst and introduces a simple method to integrate the effect of temporal storage in the unsaturated zone. In order to investigate the applicability of the developed methodology, simulation results are validated against available field measurement data. The criteria maps from the PaPRIKa vulnerability-mapping method are used to document the groundwater flow model. The FEFLOW model is employed for the simulation of the saturated zone of Palaikastro-Chochlakies karst aquifer, in the island of Crete, Greece, for the hydrological years 2010-2012. The simulated water table reproduces typical karst characteristics, such as steep slopes and preferred drain axes, and is in good agreement with field observations. Selected calculated error indicators—Nash-Sutcliffe efficiency (NSE), root mean squared error (RMSE) and model efficiency (E')—are within acceptable value ranges. Results indicate that different storage processes take place in different parts of the aquifer. The north-central part seems to be more sensitive to diffuse recharge, while the southern part is affected primarily by precipitation events. Sensitivity analysis is performed on the parameters of hydraulic conductivity and specific yield. The methodology is used to estimate the feasibility of artificial aquifer recharge (AAR) at the study area. Based on the developed methodology, guidelines were provided for the selection of the appropriate AAR scenario that has positive impact on the water table.

  10. A coupled groundwater-flow-modelling and vulnerability-mapping methodology for karstic terrain management

    Science.gov (United States)

    Kavouri, Konstantina P.; Karatzas, George P.; Plagnes, Valérie

    2017-08-01

    A coupled groundwater-flow-modelling and vulnerability-mapping methodology for the management of karst aquifers with spatial variability is developed. The methodology takes into consideration the duality of flow and recharge in karst and introduces a simple method to integrate the effect of temporal storage in the unsaturated zone. In order to investigate the applicability of the developed methodology, simulation results are validated against available field measurement data. The criteria maps from the PaPRIKa vulnerability-mapping method are used to document the groundwater flow model. The FEFLOW model is employed for the simulation of the saturated zone of Palaikastro-Chochlakies karst aquifer, in the island of Crete, Greece, for the hydrological years 2010-2012. The simulated water table reproduces typical karst characteristics, such as steep slopes and preferred drain axes, and is in good agreement with field observations. Selected calculated error indicators—Nash-Sutcliffe efficiency (NSE), root mean squared error (RMSE) and model efficiency (E')—are within acceptable value ranges. Results indicate that different storage processes take place in different parts of the aquifer. The north-central part seems to be more sensitive to diffuse recharge, while the southern part is affected primarily by precipitation events. Sensitivity analysis is performed on the parameters of hydraulic conductivity and specific yield. The methodology is used to estimate the feasibility of artificial aquifer recharge (AAR) at the study area. Based on the developed methodology, guidelines were provided for the selection of the appropriate AAR scenario that has positive impact on the water table.

  11. [Groundwater].

    Science.gov (United States)

    González De Posada, Francisco

    2012-01-01

    From the perspective of Hydrogeology, the concept and an introductory general typology of groundwater are established. From the perspective of Geotechnical Engineering works, the physical and mathematical equations of the hydraulics of permeable materials, which are implemented, by electric analogical simulation, to two unique cases of global importance, are considered: the bailing during the construction of the dry dock of the "new shipyard of the Bahia de Cádiz" and the waterproofing of the "Hatillo dam" in the Dominican Republic. From a physical fundamental perspective, the theories which are the subset of "analogical physical theories of Fourier type transport" are related, among which the one constituted by the laws of Adolf Fick in physiology occupies a historic role of some relevance. And finally, as a philosophical abstraction of so much useful mathematical process, the one which is called "the Galilean principle of the mathematical design of the Nature" is dealt with.

  12. Impact of Groundwater Level on Nitrate Nitrogen Accumulation in the Vadose Zone Beneath a Cotton Field

    Directory of Open Access Journals (Sweden)

    Xiyun Jiao

    2017-02-01

    Full Text Available In this study, the impacts of groundwater level on nitrate nitrogen accumulation in the vadose zone of a cotton field were investigated. Experiments were conducted in a cotton field at the CAS Ecological Agricultural Experiment Station in Nanpi from 2008 to 2010. A vertical observation well was drilled, and time-domain reflectometry probes and soil solution extractors were installed every 50 cm in the walls of the well to a depth of 5 m. The soil water content was monitored, and soil solution samples were obtained and analyzed every six days throughout the growing seasons during the three studied years. Additionally, a water consumption experiment was conducted, and the topsoil water content and leaf area index were measured in the cotton field. The resulting data were used to estimate parameters for use in a soil hydraulic and nitrate nitrogen movement model, and cotton evapotranspiration was calculated using the Penman–Monteith method. Groundwater level increases and decreases of ±4 m were simulated during a ten-year period using HYDRUS-1D. The results showed significant nitrate nitrogen accumulation in the vadose zone when the groundwater level remained unchanged or decreased, with increased accumulation as the groundwater depth increased. Additionally, increased precipitation and a deeper groundwater level resulted in greater nitrate nitrogen leaching in the cotton root zone. Therefore, irrigation and fertilization strategies should be adjusted based on precipitation conditions and groundwater depth.

  13. Application of RBFN network and GM (1, 1) for groundwater level simulation

    Science.gov (United States)

    Li, Zijun; Yang, Qingchun; Wang, Luchen; Martín, Jordi Delgado

    2016-10-01

    Groundwater is a prominent resource of drinking and domestic water in the world. In this context, a feasible water resources management plan necessitates acceptable predictions of groundwater table depth fluctuations, which can help ensure the sustainable use of a watershed's aquifers for urban and rural water supply. Due to the difficulties of identifying non-linear model structure and estimating the associated parameters, in this study radial basis function neural network (RBFNN) and GM (1, 1) models are used for the prediction of monthly groundwater level fluctuations in the city of Longyan, Fujian Province (South China). The monthly groundwater level data monitored from January 2003 to December 2011 are used in both models. The error criteria are estimated using the coefficient of determination (R 2), mean absolute error (E) and root mean squared error (RMSE). The results show that both the models can forecast the groundwater level with fairly high accuracy, but the RBFN network model can be a promising tool to simulate and forecast groundwater level since it has a relatively smaller RMSE and MAE.

  14. Characterizing the regional pattern and temporal change of groundwater levels by analyses of a well log data set

    Institute of Scientific and Technical Information of China (English)

    Mahmuda PARVIN; Naoyuki TADAKUMA; Hisafumi ASAUE; Katsuaki KOIKE

    2011-01-01

    Preservation of the amount and quality of groundwater resources is an important issue around the world.Changes in groundwater levels need to be monitored in efforts to preserve groundwater.This study investigates suitable methods to characterize changes in the groundwater level and determine the factors involved.The area of Kumamoto,a city in central Kyushu,southwest Japan,was selected to demonstrate the usefulness of the methods because this area is one of the richest in Japan in terms of groundwater resources and takes all its water from groundwater.Data of the groundwater level recorded at 69 wells from 1979 to 2007 were used in geostatistical and correlogram analyses.First,strong correlation between the topography and groundwater level was identified.Incorporating this correlation into spatial modeling of the groundwater level,co-kriging was demonstrated to be more accurate than ordinary kriging.The co-kriging results clarified the hydraulic characteristics of the Kumamoto area; the patterns of shallow and deep groundwater levels were agreeable generally,and the general trends of their annual average levels were similar regardless of precipitation.Another important feature was that the correlograms for the precipitation amount and groundwater level had a constant shape and changed smoothly with a change in lag time regardless of the precipitation only in the area of Togawa lava.These characteristics are probably due to the connections between shallow and deep aquifers and the high permeability of Togawa lava.

  15. Simulation of the effects of rainfall and groundwater use on historical lake water levels, groundwater levels, and spring flows in central Florida

    Science.gov (United States)

    O'Reilly, Andrew M.; Roehl, Edwin A.; Conrads, Paul A.; Daamen, Ruby C.; Petkewich, Matthew D.

    2014-01-01

    The urbanization of central Florida has progressed substantially in recent decades, and the total population in Lake, Orange, Osceola, Polk, and Seminole Counties more than quadrupled from 1960 to 2010. The Floridan aquifer system is the primary source of water for potable, industrial, and agricultural purposes in central Florida. Despite increases in groundwater withdrawals to meet the demand of population growth, recharge derived by infiltration of rainfall in the well-drained karst terrain of central Florida is the largest component of the long-term water balance of the Floridan aquifer system. To complement existing physics-based groundwater flow models, artificial neural networks and other data-mining techniques were used to simulate historical lake water level, groundwater level, and spring flow at sites throughout the area. Historical data were examined using descriptive statistics, cluster analysis, and other exploratory analysis techniques to assess their suitability for more intensive data-mining analysis. Linear trend analyses of meteorological data collected by the National Oceanic and Atmospheric Administration at 21 sites indicate 67 percent of sites exhibited upward trends in air temperature over at least a 45-year period of record, whereas 76 percent exhibited downward trends in rainfall over at least a 95-year period of record. Likewise, linear trend analyses of hydrologic response data, which have varied periods of record ranging in length from 10 to 79 years, indicate that water levels in lakes (307 sites) were about evenly split between upward and downward trends, whereas water levels in 69 percent of wells (out of 455 sites) and flows in 68 percent of springs (out of 19 sites) exhibited downward trends. Total groundwater use in the study area increased from about 250 million gallons per day (Mgal/d) in 1958 to about 590 Mgal/d in 1980 and remained relatively stable from 1981 to 2008, with a minimum of 559 Mgal/d in 1994 and a maximum of 773

  16. Application of artificial neural network model for groundwater level forecasting in a river island with artificial influencing factors

    Science.gov (United States)

    Lee, Sanghoon; Yoon, Heesung; Park, Byeong-Hak; Lee, Kang-Kun

    2017-04-01

    Groundwater use has been increased for various purposes like agriculture, industry or drinking water in recent years, the issue related to sustainability on the groundwater use also has been raised. Accordingly, forecasting the groundwater level is of great importance for planning sustainable use of groundwater. In a small island surrounded by the Han River, South Korea, seasonal fluctuation of the groundwater level is characterized by multiple factors such as recharge/discharge event of the Paldang dam, Water Curtain Cultivation (WCC) during the winter season, operation of Groundwater Heat Pump System (GWHP). For a period when the dam operation is only occurred in the study area, a prediction of the groundwater level can be easily achieved by a simple cross-correlation model. However, for a period when the WCC and the GWHP systems are working together, the groundwater level prediction is challenging due to its unpredictable operation of the two systems. This study performed Artificial Neural Network (ANN) model to forecast the groundwater level in the river area reflecting the various predictable/unpredictable factors. For constructing the ANN models, two monitoring wells, YSN1 and YSO8, which are located near the injection and abstraction wells for the GWHP system were selected, respectively. By training with the groundwater level data measured in January 2015 to August 2015, response of groundwater level by each of the surface water level, the WCC and the GWHP system were evaluated. Consequentially, groundwater levels in December 2015 to March 2016 were predicted by ANN models, providing optimal fits in comparison to the observed water levels. This study suggests that the ANN model is a useful tool to forecast the groundwater level in terms of the management of groundwater. Acknowledgement : Financial support was provided by the "R&D Project on Environmental Management of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003) This research was

  17. Effect of Different Groundwater Levels on Seismic Dynamic Response and Failure Mode of Sandy Slope.

    Directory of Open Access Journals (Sweden)

    Shuai Huang

    Full Text Available Heavy seismic damage tends to occur in slopes when groundwater is present. The main objectives of this paper are to determine the dynamic response and failure mode of sandy slope subjected simultaneously to seismic forces and variable groundwater conditions. This paper applies the finite element method, which is a fast and efficient design tool in modern engineering analysis, to evaluate dynamic response of the slope subjected simultaneously to seismic forces and variable groundwater conditions. Shaking table test is conducted to analyze the failure mode and verify the accuracy of the finite element method results. The research results show that dynamic response values of the slope have different variation rules under near and far field earthquakes. And the damage location and pattern of the slope are different in varying groundwater conditions. The destruction starts at the top of the slope when the slope is in no groundwater, which shows that the slope appears obvious whipping effect under the earthquake. The destruction starts at the toe of the slope when the slope is in the high groundwater levels. Meanwhile, the top of the slope shows obvious seismic subsidence phenomenon after earthquake. Furthermore, the existence of the groundwater has a certain effect of damping.

  18. Sensitivity of GRACE-derived estimates of groundwater-level changes in southern Ontario, Canada

    Science.gov (United States)

    Hachborn, Ellen; Berg, Aaron; Levison, Jana; Ambadan, Jaison Thomas

    2017-06-01

    Amidst changing climates, understanding the world's water resources is of increasing importance. In Ontario, Canada, low water conditions are currently assessed using only precipitation and watershed-based stream gauges by the Conservation Authorities in Ontario and the Ministry of Natural Resources and Forestry. Regional groundwater-storage changes in Ontario are not currently measured using satellite data by research institutes. In this study, contributions from the Gravity Recovery and Climate Experiment (GRACE) data are compared to a hydrogeological database covering southern Ontario from 2003 to 2013, to determine the suitability of GRACE total water storage estimates for monitoring groundwater storage in this location. Terrestrial water storage data from GRACE were used to determine monthly groundwater storage (GWS) anomaly values. GWS values were also determined by multiplying groundwater-level elevations (from the Provincial Groundwater Monitoring Network wells) by specific yield. Comparisons of GRACE-derived GWS to well-based GWS data determined that GRACE is sufficiently sensitive to obtain a meaningful signal in southern Ontario. Results show that GWS values produced by GRACE are useful for identifying regional changes in groundwater storage in areas with limited available hydrogeological characterization data. Results also indicate that GRACE may have an ability to forecast changes in groundwater storage, which will become useful when monitoring climate shifts in the near future.

  19. Effect of Different Groundwater Levels on Seismic Dynamic Response and Failure Mode of Sandy Slope

    Science.gov (United States)

    Huang, Shuai; Lv, Yuejun; Peng, Yanju; Zhang, Lifang; Xiu, Liwei

    2015-01-01

    Heavy seismic damage tends to occur in slopes when groundwater is present. The main objectives of this paper are to determine the dynamic response and failure mode of sandy slope subjected simultaneously to seismic forces and variable groundwater conditions. This paper applies the finite element method, which is a fast and efficient design tool in modern engineering analysis, to evaluate dynamic response of the slope subjected simultaneously to seismic forces and variable groundwater conditions. Shaking table test is conducted to analyze the failure mode and verify the accuracy of the finite element method results. The research results show that dynamic response values of the slope have different variation rules under near and far field earthquakes. And the damage location and pattern of the slope are different in varying groundwater conditions. The destruction starts at the top of the slope when the slope is in no groundwater, which shows that the slope appears obvious whipping effect under the earthquake. The destruction starts at the toe of the slope when the slope is in the high groundwater levels. Meanwhile, the top of the slope shows obvious seismic subsidence phenomenon after earthquake. Furthermore, the existence of the groundwater has a certain effect of damping. PMID:26560103

  20. Effect of Different Groundwater Levels on Seismic Dynamic Response and Failure Mode of Sandy Slope.

    Science.gov (United States)

    Huang, Shuai; Lv, Yuejun; Peng, Yanju; Zhang, Lifang; Xiu, Liwei

    2015-01-01

    Heavy seismic damage tends to occur in slopes when groundwater is present. The main objectives of this paper are to determine the dynamic response and failure mode of sandy slope subjected simultaneously to seismic forces and variable groundwater conditions. This paper applies the finite element method, which is a fast and efficient design tool in modern engineering analysis, to evaluate dynamic response of the slope subjected simultaneously to seismic forces and variable groundwater conditions. Shaking table test is conducted to analyze the failure mode and verify the accuracy of the finite element method results. The research results show that dynamic response values of the slope have different variation rules under near and far field earthquakes. And the damage location and pattern of the slope are different in varying groundwater conditions. The destruction starts at the top of the slope when the slope is in no groundwater, which shows that the slope appears obvious whipping effect under the earthquake. The destruction starts at the toe of the slope when the slope is in the high groundwater levels. Meanwhile, the top of the slope shows obvious seismic subsidence phenomenon after earthquake. Furthermore, the existence of the groundwater has a certain effect of damping.

  1. Fe and Mn levels regulated by agricultural activities in alluvial groundwaters underneath a flooded paddy field

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kangjoo [School of Civil and Environmental Engineering, Kunsan National University, Jeonbuk 573-701 (Korea, Republic of)], E-mail: kangjoo@kunsan.ac.kr; Kim, Hyun-Jung; Choi, Byoung-Young; Kim, Seok-Hwi; Park, Ki-hoon [School of Civil and Environmental Engineering, Kunsan National University, Jeonbuk 573-701 (Korea, Republic of); Park, Eungyu [Department of Geology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Koh, Dong-Chan [Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Yun, Seong-Taek [Department of Earth and Environmental Sciences, Korea University, Seoul 136-701 (Korea, Republic of)

    2008-01-15

    Iron and Mn concentrations in fresh groundwaters of alluvial aquifers are generally high in reducing conditions reflecting low SO{sub 4} concentrations. The mass balance and isotopic approaches of this study demonstrate that reduction of SO{sub 4}, supplied from agricultural activities such as fertilization and irrigation, is important in lowering Fe and Mn levels in alluvial groundwaters underneath a paddy field. This study was performed to investigate the processes regulating Fe and Mn levels in groundwaters of a point bar area, which has been intensively used for flood cultivation. Four multilevel-groundwater samplers were installed to examine the relationship between geology and the vertical changes in water chemistry. The results show that Fe and Mn levels are regulated by the presence of NO{sub 3} at shallow depths and by SO{sub 4} reduction at the greater depths. Isotopic and mass balance analyses revealed that NO{sub 3} and SO{sub 4} in groundwater are mostly supplied from the paddy field, suggesting that the Fe-and Mn-rich zone of the study area is confined by the agricultural activities. For this reason, the geologic conditions controlling the infiltration of agrochemicals are also important for the occurrence of Fe/Mn-rich groundwaters in the paddy field area.

  2. Evaluation of groundwater levels in the South Platte River alluvial aquifer, Colorado, 1953-2012, and design of initial well networks for monitoring groundwater levels

    Science.gov (United States)

    Wellman, Tristan

    2015-01-01

    The South Platte River and underlying alluvial aquifer form an important hydrologic resource in northeastern Colorado that provides water to population centers along the Front Range and to agricultural communities across the rural plains. Water is regulated based on seniority of water rights and delivered using a network of administration structures that includes ditches, reservoirs, wells, impacted river sections, and engineered recharge areas. A recent addendum to Colorado water law enacted during 2002-2003 curtailed pumping from thousands of wells that lacked authorized augmentation plans. The restrictions in pumping were hypothesized to increase water storage in the aquifer, causing groundwater to rise near the land surface at some locations. The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board and the Colorado Water Institute, completed an assessment of 60 years (yr) of historical groundwater-level records collected from 1953 to 2012 from 1,669 wells. Relations of "high" groundwater levels, defined as depth to water from 0 to 10 feet (ft) below land surface, were compared to precipitation, river discharge, and 36 geographic and administrative attributes to identify natural and human controls in areas with shallow groundwater.

  3. A Study of the Groundwater Level Spatial Variability in the Messara Valley of Crete

    Science.gov (United States)

    Varouchakis, E. A.; Hristopulos, D. T.; Karatzas, G. P.

    2009-04-01

    The island of Crete (Greece) has a dry sub-humid climate and marginal groundwater resources, which are extensively used for agricultural activities and human consumption. The Messara valley is located in the south of the Heraklion prefecture, it covers an area of 398 km2, and it is the largest and most productive valley of the island. Over-exploitation during the past thirty (30) years has led to a dramatic decrease of thirty five (35) meters in the groundwater level. Possible future climatic changes in the Mediterranean region, potential desertification, population increase, and extensive agricultural activity generate concern over the sustainability of the water resources of the area. The accurate estimation of the water table depth is important for an integrated groundwater resource management plan. This study focuses on the Mires basin of the Messara valley for reasons of hydro-geological data availability and geological homogeneity. The research goal is to model and map the spatial variability of the basin's groundwater level accurately. The data used in this study consist of seventy (70) piezometric head measurements for the hydrological year 2001-2002. These are unevenly distributed and mostly concentrated along a temporary river that crosses the basin. The range of piezometric heads varies from an extreme low value of 9.4 meters above sea level (masl) to 62 masl, for the wet period of the year (October to April). An initial goal of the study is to develop spatial models for the accurate generation of static maps of groundwater level. At a second stage, these maps should extend the models to dynamic (space-time) situations for the prediction of future water levels. Preliminary data analysis shows that the piezometric head variations are not normally distributed. Several methods including Box-Cox transformation and a modified version of it, transgaussian Kriging, and Gaussian anamorphosis have been used to obtain a spatial model for the piezometric head. A

  4. Preliminary investigation of the effects of sea-level rise on groundwater levels in New Haven, Connecticut

    Science.gov (United States)

    Bjerklie, David M.; Mullaney, John R.; Stone, Janet R.; Skinner, Brian J.; Ramlow, Matthew A.

    2012-01-01

    Global sea level rose about 0.56 feet (ft) (170 millimeters (mm)) during the 20th century. Since the 1960s, sea level has risen at Bridgeport, Connecticut, about 0.38 ft (115 mm), at a rate of 0.008 ft (2.56 mm + or - 0.58 mm) per year. With regional subsidence, and with predicted global climate change, sea level is expected to continue to rise along the northeast coast of the United States through the 21st century. Increasing sea levels will cause groundwater levels in coastal areas to rise in order to adjust to the new conditions. Some regional climate models predict wetter climate in the northeastern United States under some scenarios. Scenarios for the resulting higher groundwater levels have the potential to inundate underground infrastructure in lowlying coastal cities. New Haven is a coastal city in Connecticut surrounded and bisected by tidally affected waters. Monitoring of water levels in wells in New Haven from August 2009 to July 2010 indicates the complex effects of urban influence on groundwater levels. The response of groundwater levels to recharge and season varied considerably from well to well. Groundwater temperatures varied seasonally, but were warmer than what was typical for Connecticut, and they seem to reflect the influence of the urban setting, including the effects of conduits for underground utilities. Specific conductance was elevated in many of the wells, indicating the influence of urban activities or seawater in Long Island Sound. A preliminary steady-state model of groundwater flow for part of New Haven was constructed using MODFLOW to simulate current groundwater levels (2009-2010) and future groundwater levels based on scenarios with a rise of 3 ft (0.91 meters (m)) in sea level, which is predicted for the end of the 21st century. An additional simulation was run assuming a 3-ft rise in sea level combined with a 12-percent increase in groundwater recharge. The model was constructed from existing hydrogeologic information for the

  5. Map visualization of groundwater withdrawals at the sub-basin scale

    Science.gov (United States)

    Goode, Daniel J.

    2016-01-01

    A simple method is proposed to visualize the magnitude of groundwater withdrawals from wells relative to user-defined water-resource metrics. The map is solely an illustration of the withdrawal magnitudes, spatially centered on wells—it is not capture zones or source areas contributing recharge to wells. Common practice is to scale the size (area) of withdrawal well symbols proportional to pumping rate. Symbols are drawn large enough to be visible, but not so large that they overlap excessively. In contrast to such graphics-based symbol sizes, the proposed method uses a depth-rate index (length per time) to visualize the well withdrawal rates by volumetrically consistent areas, called “footprints”. The area of each individual well’s footprint is the withdrawal rate divided by the depth-rate index. For example, the groundwater recharge rate could be used as a depth-rate index to show how large withdrawals are relative to that recharge. To account for the interference of nearby wells, composite footprints are computed by iterative nearest-neighbor distribution of excess withdrawals on a computational and display grid having uniform square cells. The map shows circular footprints at individual isolated wells and merged footprint areas where wells’ individual footprints overlap. Examples are presented for depth-rate indexes corresponding to recharge, to spatially variable stream baseflow (normalized by basin area), and to the average rate of water-table decline (scaled by specific yield). These depth-rate indexes are water-resource metrics, and the footprints visualize the magnitude of withdrawals relative to these metrics.

  6. Groundwater Level Changes Due to Extreme Weather—An Evaluation Tool for Sustainable Water Management

    Directory of Open Access Journals (Sweden)

    Jadwiga R. Ziolkowska

    2017-02-01

    Full Text Available In the past decade, extreme and exceptional droughts have significantly impacted many economic sectors in the US, especially in California, Oklahoma, and Texas. The record drought of 2011–2014 affected almost 90% of Texas areas and 95% of Oklahoma state areas. In 2011 alone, around $1.6 billion in agricultural production were lost as a result of drought in Oklahoma, and $7.6 billion in Texas. The agricultural sectors in Oklahoma and Texas rely mainly on groundwater resources from the non-replenishable Ogallala Aquifer in Panhandle and other aquifers around the states. The exceptional droughts of 2011–2014 not only caused meteorologically induced water scarcity (due to low precipitation, but also prompted farmers to overuse groundwater to maintain the imperiled production. Comprehensive studies on groundwater levels, and thus the actual water availability/scarcity across all aquifers in Oklahoma and Texas are still limited. Existing studies are mainly focused on a small number of selected sites or aquifers over a short time span of well monitoring, which does not allow for a holistic geospatial and temporal evaluation of groundwater level variations. This paper aims at addressing those issues with the proposed geospatial groundwater visualization model to assess availability of groundwater resources for agricultural, industrial, and municipal uses both in Oklahoma and Texas in the time frame of 2003–2014. The model is an evaluation tool that can be used by decision-makers for designing sustainable water management practices and by teachers and researchers for educational purposes.

  7. Extent, perception and mitigation of damage due to high groundwater levels in the city of Dresden, Germany

    Science.gov (United States)

    Kreibich, H.; Thieken, A. H.; Grunenberg, H.; Ullrich, K.; Sommer, T.

    2009-07-01

    Flood risk analysis and management plans mostly neglect groundwater flooding, i.e. high groundwater levels. However, rising groundwater may cause considerable damage to buildings and infrastructure. To improve the knowledge about groundwater flooding and support risk management, a survey was undertaken in the city of Dresden (Saxony, Germany), resulting in 605 completed interviews with private households endangered by high groundwater levels. The reported relatively low flood impact and damage of groundwater floods in comparison with mixed floods was reflected by its scarce perception: Hardly anybody thinks about the risk of groundwater flooding. The interviewees thought that public authorities and not themselves, should be mainly responsible for preparedness and emergency response. Up to now, people do not include groundwater risk in their decision processes on self protection. The implementation of precautionary measures does not differ between households with groundwater or with mixed flood experience. However, less households undertake emergency measures when expecting a groundwater flood only. The state of preparedness should be further improved via an intensified risk communication about groundwater flooding by the authorities. Conditions to reach the endangered population are good, since 70% of the interviewed people are willing to inform themselves about groundwater floods. Recommendations for an improved risk communication are given.

  8. Potential effects of groundwater pumping on water levels, phreatophytes, and spring discharges in Spring and Snake Valleys, White Pine County, Nevada, and adjacent areas in Nevada and Utah

    Science.gov (United States)

    Halford, Keith J.; Plume, Russell W.

    2011-01-01

    Assessing hydrologic effects of developing groundwater supplies in Snake Valley required numerical, groundwater-flow models to estimate the timing and magnitude of capture from streams, springs, wetlands, and phreatophytes. Estimating general water-table decline also required groundwater simulation. The hydraulic conductivity of basin fill and transmissivity of basement-rock distributions in Spring and Snake Valleys were refined by calibrating a steady state, three-dimensional, MODFLOW model of the carbonate-rock province to predevelopment conditions. Hydraulic properties and boundary conditions were defined primarily from the Regional Aquifer-System Analysis (RASA) model except in Spring and Snake Valleys. This locally refined model was referred to as the Great Basin National Park calibration (GBNP-C) model. Groundwater discharges from phreatophyte areas and springs in Spring and Snake Valleys were simulated as specified discharges in the GBNP-C model. These discharges equaled mapped rates and measured discharges, respectively. Recharge, hydraulic conductivity, and transmissivity were distributed throughout Spring and Snake Valleys with pilot points and interpolated to model cells with kriging in geologically similar areas. Transmissivity of the basement rocks was estimated because thickness is correlated poorly with transmissivity. Transmissivity estimates were constrained by aquifer-test results in basin-fill and carbonate-rock aquifers. Recharge, hydraulic conductivity, and transmissivity distributions of the GBNP-C model were estimated by minimizing a weighted composite, sum-of-squares objective function that included measurement and Tikhonov regularization observations. Tikhonov regularization observations were equations that defined preferred relations between the pilot points. Measured water levels, water levels that were simulated with RASA, depth-to-water beneath distributed groundwater and spring discharges, land-surface altitudes, spring discharge at

  9. Aquifer-Circulating Water Curtain Cultivation System To Recover Groundwater Level And Temperature

    Science.gov (United States)

    Kim, Y.; Ko, K.; Chon, C.; Oh, S.

    2011-12-01

    Groundwater temperature, which generally ranges 14 to 16 degree of Celsius all year long, can be said to be 'constant' compared to the amplitude of daily variation of air temperature or surface water. Water curtain cultivating method utilizes this 'constant' groundwater temperature to warm up the inside of greenhouse during winter night by splash groundwater on the roof of inner greenhouse. The area of water curtain cultivation system have increased up to 107.5 square kilometers as of 2006 since when it is first introduced to South Korea in 1984. Groundwater shortage problem became a great issue in a concentrated water curtain cultivation area because the pumped and splashed groundwater is abandoned to nearby stream and natural recharge rate is reduced by greenhouses. The amount of groundwater use for water curtain cultivation system in South Korea is calculated to be 587 million cubic meters which is 35% of national agricultural use of groundwater. A new water curtain cultivation system coupled with aquifer circulating of the splashed groundwater and greenhouse roof-top rainwater harvesting is developed and applied to field site in Nonsan-si, Chungnam province to minimize groundwater shortage problem and recover groundwater level. The aquifer circulating water curtain cultivation system is consist of a pumping well and a injection well of 80 m deep, groundwater transfer and splashing system, recovery tank and rainwater collecting waterway. The distance between injection and pumping well is 15 m and an observation well is installed in the middle of the wells. To characterize hydrogeological properties of this site, hydraulic test such as pumping tests and tracer tests with dye tracer, thermal tracer and ion tracer. Once the integrated system is constructed in this site, hydraulic head in all the wells and temperature of air, recovery tank and groundwater in all the wells are monitored during the operation for 3months in winter season. Hydraulic test and tracer

  10. Elaboration of groundwater quality maps using Kriging methods; Creacion de mapas de calidad de aguas subterraneas mediante metodos de Krigeaje

    Energy Technology Data Exchange (ETDEWEB)

    Chica-Olmo, M.; Luque-Espinar, J. A.

    2003-07-01

    Two different geostatistical approaches for the elaboration of groundwater quality maps are presented. Firstly, the main theoretical aspects concerning to the two estimation methods used, ordinary kriging and indicator kriging, are described. They share a common theoretical basis but focus their estimations in different terms. The former gives the most probable value of a groundwater quality parameter in the aquifer, e. g. nitrate contents, so that is applied to map it spatial distribution. Whereas the latter estimates is applied to estimate the spatial probability distribution function of surpassing a given threshold or alert value for the experimental parameter. A case study regarding the Vega of Granada aquifer is also presented. The comparative advantages offered by each of these methods are discussed, taking into account the random behaviour shown by the studied variable. It is concluded that maps created by both methods provide value information of great interest for decision-making with regards to water quality control. (Author) 10 refs.

  11. Theory and Method for Identifying Well Water Level Anomalies in a Groundwater Overdraft Area

    Institute of Scientific and Technical Information of China (English)

    Zhang Suxin; Zhang Ziguang; Ren Xiaoxia; Wang Xiang

    2007-01-01

    The overexploitation of underground water leads to the continuous drawdown of groundwater levels, change of water quality and dry-up in dynamic water level observation wells. Due to land subsidence, the well pipes uplift and the observation piping systems are damaged. These environmental geology problems can present serious difficulties for the identification of earthquake anomalies by groundwater level observation. Basied on hydrogeological theories and methods, the paper analyzes the relations of the water balance state of aquifers with stressstrain conditions and the water level regime, and then discusses preliminarily the theory and method for identifying well water level anomalies in a groundwater overdraft area. The result shows that we can accurately judge the nature of the anomaly according to the diffusion character of the drawdown funnel in the well area in combination with the aforementioned theory and method and multi-year variation patterns obtained from existing data. The results of the research are helpful for distinguishing the influence of single centralized water pumping from the long-term overdraft of water on the water level, correctly recognizing water level anomalies in the groundwater overdraft area and increasing the level of earthquake analysis and prediction.

  12. Effects of sea-level rise on barrier island groundwater system dynamics: ecohydrological implications

    Science.gov (United States)

    Masterson, John P.; Fienen, Michael N.; Thieler, E. Robert; Gesch, Dean B.; Gutierrez, Benjamin T.; Plant, Nathaniel G.

    2014-01-01

    We used a numerical model to investigate how a barrier island groundwater system responds to increases of up to 60 cm in sea level. We found that a sea-level rise of 20 cm leads to substantial changes in the depth of the water table and the extent and depth of saltwater intrusion, which are key determinants in the establishment, distribution and succession of vegetation assemblages and habitat suitability in barrier islands ecosystems. In our simulations, increases in water-table height in areas with a shallow depth to water (or thin vadose zone) resulted in extensive groundwater inundation of land surface and a thinning of the underlying freshwater lens. We demonstrated the interdependence of the groundwater response to island morphology by evaluating changes at three sites. This interdependence can have a profound effect on ecosystem composition in these fragile coastal landscapes under long-term changing climatic conditions.

  13. A method to filter out the effect of river stage fluctuation on groundwater level using time series models

    Science.gov (United States)

    Yoon, Heesung; Park, Eungyu; Yoon, Pilsun; Lee, Eunhee; Kim, Gyoo-Bum

    2016-04-01

    A method to filter out the effect of river stage fluctuations on groundwater level was designed using an artificial neural network-based time series model of groundwater level prediction. The designed method was applied to daily groundwater level data near the Gangjeong-Koryeong Barrage in the Nakdong river, South Korea. First, one-step ahead direct prediction time series models were successfully developed for both cases of before and after the barrage construction using past measurement data of rainfall, river stage, and groundwater level as inputs. The correlation coefficient values between observed and predicted data were over 0.97. Based on the direct prediction models, recursive prediction models for the simulation of groundwater level fluctuations were designed. The effect of river stage fluctuation on groundwater level data was filtered out by setting a constant value for river stage inputs of the recursive time series models. The hybrid water table fluctuation method was employed to estimate the groundwater recharge using the filtered data. The calculated ratios of groundwater recharge to precipitation before and after the barrage construction were 11.0% and 4.3%, respectively. It is expected that the proposed method can be a useful tool for groundwater level prediction and recharge estimation in the riverside area.

  14. Analysis of 1997–2008 groundwater level changes in the upper Deschutes Basin, Central Oregon

    Science.gov (United States)

    Gannett, Marshall W.; Lite, Kenneth E.

    2013-01-01

    Groundwater-level monitoring in the upper Deschutes Basin of central Oregon from 1997 to 2008 shows water-level declines in some places that are larger than might be expected from climate variations alone, raising questions regarding the influence of groundwater pumping, canal lining (which decreases recharge), and other human influences. Between the mid-1990s and mid-2000s, water levels in the central part of the basin near Redmond steadily declined as much as 14 feet. Water levels in the Cascade Range, in contrast, rose more than 20 feet from the mid-1990s to about 2000, and then declined into the mid-2000s, with little or no net change. An existing U.S. Geological Survey regional groundwater-flow model was used to gain insights into groundwater-level changes from 1997 to 2008, and to determine the relative influence of climate, groundwater pumping, and irrigation canal lining on observed water-level trends. To utilize the model, input datasets had to be extended to include post-1997 changes in groundwater pumping, changes in recharge from precipitation, irrigation canal leakage, and deep percolation of applied irrigation water (also known as on-farm loss). Mean annual groundwater recharge from precipitation during the 1999–2008 period was 25 percent less than during the 1979–88 period because of drying climate conditions. This decrease in groundwater recharge is consistent with measured decreases in streamflow and discharge to springs. For example, the mean annual discharge of Fall River, which is a spring-fed stream, decreased 12 percent between the 1979–88 and 1999–2008 periods. Between the mid-1990s and late 2000s, groundwater pumping for public-supply and irrigation uses increased from about 32,500 to 52,000 acre-feet per year, partially because of population growth. Between 1997 and 2008, the rate of recharge from leaking irrigation canals decreased by about 58,000 acre-feet per year as a result of lining and piping of canals. Decreases in recharge

  15. The construction of synthetic maps of groundwater vulnerability on the example of catchment area of Žilůvky stream

    Directory of Open Access Journals (Sweden)

    Kristýna Kubová

    2007-01-01

    Full Text Available The term “vulnerability of groundwater to contamination” was introduced by French hydrogeologist J. Margat in the late 1960s. The idea of describing the degree of vulnerability of groundwater to contaminants as a function of hydrogeological conditions by means of maps was conceived to show that the protection provided by the natural environment varies at different locations. Groundwater vulnerability maps belong to category of special-purpose environmental maps and introduce one of the possible tool to solve groundwater protection. The synthetic map of relevant catchment area of Žilůvky stream was composed in the program ArcGIS as a intersection between 4 partial maps: the map of soil character according to infiltration capability, the map of geological structure according to permeability, the map of unsaturated zone potency and the map of karst phenomens, springs and boreholes localization. The final map was presented in 4 variants A – D according to meaning of layers which have the influence on groundwater vulnerability.

  16. Statistical analysis and mapping of water levels in the Biscayne aquifer, water conservation areas, and Everglades National Park, Miami-Dade County, Florida, 2000–2009

    Science.gov (United States)

    Prinos, Scott T.; Dixon, Joann F.

    2016-02-25

    Statistical analyses and maps representing mean, high, and low water-level conditions in the surface water and groundwater of Miami-Dade County were made by the U.S. Geological Survey, in cooperation with the Miami-Dade County Department of Regulatory and Economic Resources, to help inform decisions necessary for urban planning and development. Sixteen maps were created that show contours of (1) the mean of daily water levels at each site during October and May for the 2000–2009 water years; (2) the 25th, 50th, and 75th percentiles of the daily water levels at each site during October and May and for all months during 2000–2009; and (3) the differences between mean October and May water levels, as well as the differences in the percentiles of water levels for all months, between 1990–1999 and 2000–2009. The 80th, 90th, and 96th percentiles of the annual maximums of daily groundwater levels during 1974–2009 (a 35-year period) were computed to provide an indication of unusually high groundwater-level conditions. These maps and statistics provide a generalized understanding of the variations of water levels in the aquifer, rather than a survey of concurrent water levels. Water-level measurements from 473 sites in Miami-Dade County and surrounding counties were analyzed to generate statistical analyses. The monitored water levels included surface-water levels in canals and wetland areas and groundwater levels in the Biscayne aquifer.

  17. Towards Multi-level Optimization: Space-Mapping and Manifold-Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Echeverria, D; Tong, C

    2006-07-24

    In this report we study space-mapping and manifold-mapping, two multi-level optimization techniques that aim at accelerating expensive optimization procedures with the aid of simple auxiliary models. Manifold-mapping improves in accuracy the solution given by space-mapping. In this report, the two mentioned techniques are basically described and then applied in the solving of two minimization problems. Several coarse models are tried, both from a two and a three level perspective. The results with these simple tests confirm the speed-up expected for the multi-level approach.

  18. Geostatistics-based groundwater-level monitoring network design and its application to the Upper Floridan aquifer, USA.

    Science.gov (United States)

    Bhat, Shirish; Motz, Louis H; Pathak, Chandra; Kuebler, Laura

    2015-01-01

    A geostatistical method was applied to optimize an existing groundwater-level monitoring network in the Upper Floridan aquifer for the South Florida Water Management District in the southeastern United States. Analyses were performed to determine suitable numbers and locations of monitoring wells that will provide equivalent or better quality groundwater-level data compared to an existing monitoring network. Ambient, unadjusted groundwater heads were expressed as salinity-adjusted heads based on the density of freshwater, well screen elevations, and temperature-dependent saline groundwater density. The optimization of the numbers and locations of monitoring wells is based on a pre-defined groundwater-level prediction error. The newly developed network combines an existing network with the addition of new wells that will result in a spatial distribution of groundwater monitoring wells that better defines the regional potentiometric surface of the Upper Floridan aquifer in the study area. The network yields groundwater-level predictions that differ significantly from those produced using the existing network. The newly designed network will reduce the mean prediction standard error by 43% compared to the existing network. The adoption of a hexagonal grid network for the South Florida Water Management District is recommended to achieve both a uniform level of information about groundwater levels and the minimum required accuracy. It is customary to install more monitoring wells for observing groundwater levels and groundwater quality as groundwater development progresses. However, budget constraints often force water managers to implement cost-effective monitoring networks. In this regard, this study provides guidelines to water managers concerned with groundwater planning and monitoring.

  19. Groundwater-level trends and forecasts, and salinity trends, in the Azraq, Dead Sea, Hammad, Jordan Side Valleys, Yarmouk, and Zarqa groundwater basins, Jordan

    Science.gov (United States)

    Goode, Daniel J.; Senior, Lisa A.; Subah, Ali; Jaber, Ayman

    2013-01-01

    Changes in groundwater levels and salinity in six groundwater basins in Jordan were characterized by using linear trends fit to well-monitoring data collected from 1960 to early 2011. On the basis of data for 117 wells, groundwater levels in the six basins were declining, on average about -1 meter per year (m/yr), in 2010. The highest average rate of decline, -1.9 m/yr, occurred in the Jordan Side Valleys basin, and on average no decline occurred in the Hammad basin. The highest rate of decline for an individual well was -9 m/yr. Aquifer saturated thickness, a measure of water storage, was forecast for year 2030 by using linear extrapolation of the groundwater-level trend in 2010. From 30 to 40 percent of the saturated thickness, on average, was forecast to be depleted by 2030. Five percent of the wells evaluated were forecast to have zero saturated thickness by 2030. Electrical conductivity was used as a surrogate for salinity (total dissolved solids). Salinity trends in groundwater were much more variable and less linear than groundwater-level trends. The long-term linear salinity trend at most of the 205 wells evaluated was not increasing, although salinity trends are increasing in some areas. The salinity in about 58 percent of the wells in the Amman-Zarqa basin was substantially increasing, and the salinity in Hammad basin showed a long-term increasing trend. Salinity increases were not always observed in areas with groundwater-level declines. The highest rates of salinity increase were observed in regional discharge areas near groundwater pumping centers.

  20. Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

    DEFF Research Database (Denmark)

    Joergensen, F.; Scheer, W.; Thomsen, S.

    2012-01-01

    revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing....../freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still...

  1. GROUNDWATER FLOW MODEL CALIBRATION USING WATER LEVEL MEASUREMENTS AT SHORT INTERVALS

    Science.gov (United States)

    Groundwater flow models are usually calibrated with respect to water level measurements collected at intervals of several months or even years. Measurements of these kinds are not sensitive to sudden or short stress conditions, such as impact from stormwater drainage flow or flas...

  2. The use of Time Domain Electromagnetic method and Continuous Vertical Electrical Sounding to map groundwater salinity in the Barotse sub-basin, Zambia

    DEFF Research Database (Denmark)

    Chongo, Mkhuzo; Wibroe, Johanne; Staal-Thomsen, K.

    2011-01-01

    This paper describes the results from the application of two geophysical exploration techniques, Time Domain Electromagnetic (TDEM) and Continuous Vertical Electrical Sounding (CVES) that have proved effective in mapping groundwater salinity variations within the sedimentary formations...

  3. Evaluation of four supervised learning methods for groundwater spring potential mapping in Khalkhal region (Iran) using GIS-based features

    Science.gov (United States)

    Naghibi, Seyed Amir; Moradi Dashtpagerdi, Mostafa

    2016-09-01

    One important tool for water resources management in arid and semi-arid areas is groundwater potential mapping. In this study, four data-mining models including K-nearest neighbor (KNN), linear discriminant analysis (LDA), multivariate adaptive regression splines (MARS), and quadric discriminant analysis (QDA) were used for groundwater potential mapping to get better and more accurate groundwater potential maps (GPMs). For this purpose, 14 groundwater influence factors were considered, such as altitude, slope angle, slope aspect, plan curvature, profile curvature, slope length, topographic wetness index (TWI), stream power index, distance from rivers, river density, distance from faults, fault density, land use, and lithology. From 842 springs in the study area, in the Khalkhal region of Iran, 70 % (589 springs) were considered for training and 30 % (253 springs) were used as a validation dataset. Then, KNN, LDA, MARS, and QDA models were applied in the R statistical software and the results were mapped as GPMs. Finally, the receiver operating characteristics (ROC) curve was implemented to evaluate the performance of the models. According to the results, the area under the curve of ROCs were calculated as 81.4, 80.5, 79.6, and 79.2 % for MARS, QDA, KNN, and LDA, respectively. So, it can be concluded that the performances of KNN and LDA were acceptable and the performances of MARS and QDA were excellent. Also, the results depicted high contribution of altitude, TWI, slope angle, and fault density, while plan curvature and land use were seen to be the least important factors.

  4. Factor weighting in DRASTIC modelling for assessing the groundwater vulnerability in Salatiga groundwater basin, Central Java Province, Indonesia

    Science.gov (United States)

    Kesuma, D. A.; Purwanto, P.; Putranto, T. T.; Rahmani, T. P. D.

    2017-06-01

    The increase in human population as well as area development in Salatiga Groundwater Basin, Central Java Province, will increase the potency of groundwater contamination in that area. Groundwater quality, especially the shallow groundwater, is very vulnerable to the contamination from industrial waste, fertilizer/agricultural waste, and domestic waste. The first step in the conservation of groundwater quality is by conducting the mapping of the groundwater vulnerability zonation against the contamination. The result of this research was groundwater vulnerability map which showed the areas vulnerable to the groundwater contamination. In this study, groundwater vulnerability map was assessed based on the DRASTIC Method and was processed spatially using Geographic Information System. The DRASTIC method is used to assess the level of groundwater vulnerability based on weighting on seven parameters, which are: depth to the water table (D), recharge (R), aquifer material (A), soil media (S), topography (T), impact of vadose zone (I), and hydraulic conductivity (C). The higher the DRASTIC Index will result in the higher vulnerability level of groundwater contamination in that area. The DRASTIC Indexes in the researched area were 85 - 100 (low vulnerability level), 101 -120 (low to moderate vulnerability level), 121 - 140 (moderate vulnerability level), 141 - 150, (moderate to high vulnerability level), and 151 - 159 (high vulnerability level). The output of this study can be used by local authority as a tool for consideration to arrange the policy for sustainable area development, especially the development in an area affecting the quality of Salatiga Groundwater Basin.

  5. Precipitation; ground-water age; ground-water nitrate concentrations, 1995-2002; and ground-water levels, 2002-03 in Eastern Bernalillo County, New Mexico

    Science.gov (United States)

    Blanchard, Paul J.

    2004-01-01

    wells during 1995, 1997, and (or) 1998. Nitrate concentrations in two wells were larger than the U.S. Environmental Protection Agency primary drinking-water regulation of 10 milligrams per liter in 1998 and in 2001. Ground-water levels were measured during June and July 2002 and during June, July, and August 2003 in 18 monitoring wells. The median change in water level for all 18 wells was a decline of 2.03 feet.

  6. GIS-based groundwater spring potential assessment and mapping in the Birjand Township, southern Khorasan Province, Iran

    Science.gov (United States)

    Pourtaghi, Zohre Sadat; Pourghasemi, Hamid Reza

    2014-05-01

    Three statistical models—frequency ratio (FR), weights-of-evidence (WofE) and logistic regression (LR)—produced groundwater-spring potential maps for the Birjand Township, southern Khorasan Province, Iran. In total, 304 springs were identified in a field survey and mapped in a geographic information system (GIS), out of which 212 spring locations were randomly selected to be modeled and the remaining 92 were used for the model evaluation. The effective factors—slope angle, slope aspect, elevation, topographic wetness index (TWI), stream power index (SPI), slope length (LS), plan curvature, lithology, land use, and distance to river, road, fault—were derived from the spatial database. Using these effective factors, groundwater spring potential was calculated using the three models, and the results were plotted in ArcGIS. The receiver operating characteristic (ROC) curves were drawn for spring potential maps and the area under the curve (AUC) was computed. The final results indicated that the FR model (AUC = 79.38 %) performed better than the WofE (AUC = 75.69 %) and LR (AUC = 63.71 %) models. Sensitivity and factor analyses concluded that the bivariate statistical index model (i.e. FR) can be used as a simple tool in the assessment of groundwater spring potential when a sufficient number of data are obtained.

  7. Screening-Level Risk Assessment for Styrene-Acrylonitrile (SAN) Trimer Detected in Soil and Groundwater

    OpenAIRE

    Kirman, C. R.; Gargas, M L; Collins, J. J.; Rowlands, J. C.

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluate...

  8. Mapping of groundwater prospective zones integrating remote sensing, geographic information systems and geophysical techniques in El-Qaà Plain area, Egypt

    Science.gov (United States)

    Abuzied, Sara M.; Alrefaee, Hamed A.

    2017-05-01

    The geospatial mapping of groundwater prospective zones is essential to support the needs of local inhabitants and agricultural activities in arid regions such as El-Qaà area, Sinai Peninsula, Egypt. The study aims to locate new wells that can serve to cope with water scarcity. The integration of remote sensing, geographic information systems (GIS) and geophysical techniques is a breakthrough for groundwater prospecting. Based on these techniques, several factors contributing to groundwater potential in El-Qaà Plain were determined. Geophysical data were supported by information derived from a digital elevation model, and from geologic, geomorphologic and hydrologic data, to reveal the promising sites. All the spatial data that represent the contributing factors were integrated and analyzed in a GIS framework to develop a groundwater prospective model. An appropriate weightage was specified to each factor based on its relative contribution towards groundwater potential, and the resulting map delineates the study area into five classes, from very poor to very good potential. The very good potential zones are located in the Quaternary deposits, with flat to gentle topography, dense lineaments and structurally controlled drainage channels. The groundwater potential map was tested against the distribution of groundwater wells and cultivated land. The integrated methodology provides a powerful tool to design a suitable groundwater management plan in arid regions.

  9. Statistical analysis of interaction between lake seepage rates and groundwater and lake levels

    Science.gov (United States)

    Ala-aho, P.; Rossi, P. M.; Klöve, B.

    2012-04-01

    In Finland, the main sources of groundwater are the esker deposits from the last ice age. Small lakes imbedded in the aquifer with no outlets or inlets are typically found in eskers. Some lakes at Rokua esker, in Northern Finland, have been suffering from changes in water stage and quality. A possible permanent decline of water level has raised considerable concern as the area is also used for recreation and tourism. Rare biotypes supported by the oligotrophic lakes can also be endangered by the level decline. Drainage of peatlands located in the discharge zone of the aquifer is a possible threat for the lakes and the whole aquifer. Drainage can potentially lower the aquifer water table which can have an effect on the groundwater-lake interaction. The aim of this study was to understand in more detail the interaction of the aquifer and the lake systems so potential causes for the lake level variations could be better understood and managed. In-depth understanding of hydrogeological system provides foundation to study the nutrient input to lakes affecting lake ecosystems. A small lake imbedded the Rokua esker aquifer was studied in detail. Direct measurements of seepage rate between the lake and the aquifer were carried out using seepage meters. Seepage was measured from six locations for eight times during May 2010 - November 2010. Precipitation was recorded with a tipping bucket rain gauge adjacent to the lake. Lake stage and groundwater levels from three piezometers were registered on an hourly interval using pressure probes. Statistical methods were applied to examine relationship between seepage measurements and levels of lake and groundwater and amount of precipitation. Distinct areas of inseepage and outseepage of the lake were distinguished with seepage meter measurements. Seepage rates showed only little variation within individual measurement locations. Nevertheless analysis revealed statistically significant correlation of seepage rate variation in four

  10. Mapping Model of Groundwater Catchment Area based on Geological Fault : Case Study in Semarang City

    Directory of Open Access Journals (Sweden)

    Qudus, N.

    2016-04-01

    Full Text Available Groundwater is a naturally renewable resource because groundwater is an integral part of hydrological cycle. However, in reality, there are many limiting factors which influence its usage, in both quality and quantity, the provision ability of groundwater will decrease if its availability is exceeded. The problems of ground water potential in both quantity and quality are always related to its constituents' characteristics or its geological element where the groundwater resides. This present study aims at determining the groundwater catchment area based on the geological condition of an area so that groundwater recharge can be accomplished. In addition, it is necessary for groundwater catchment area to comply with the geological condition. The geologically unfit area will only result in land movement or landslide if it is used as groundwater catchment area. The results of geo-electricity analysis which was conducted in Semarang city showed that there are 3 faults; Sukorejo fault, Tinjomoyo fault and Jangli fault which will be explained in detail in the paper. Those faults intersect the underground water stream in Semarang from south to north towards the Java Sea. The majority of underground water stream in Semarang flows from south to north. In contrary, the results of the analysis showed that there are some points that become local basins such as in the south area and southwest of Semarang where flow direction is on the opposite direction. In addition, the results of the analysis showed that some coastal areas in Semarang have experienced salt water intrusion.

  11. Groundwater level and nitrate concentration trends on Mountain Home Air Force Base, southwestern Idaho

    Science.gov (United States)

    Williams, Marshall L.

    2014-01-01

    Mountain Home Air Force Base in southwestern Idaho draws most of its drinking water from the regional aquifer. The base is located within the State of Idaho's Mountain Home Groundwater Management Area and is adjacent to the State's Cinder Cone Butte Critical Groundwater Area. Both areas were established by the Idaho Department of Water Resources in the early 1980s because of declining water levels in the regional aquifer. The base also is listed by the Idaho Department of Environmental Quality as a nitrate priority area. The U.S. Geological Survey, in cooperation with the U.S. Air Force, began monitoring wells on the base in 1985, and currently monitors 25 wells for water levels and 17 wells for water quality, primarily nutrients. This report provides a summary of water-level and nitrate concentration data collected primarily between 2001 and 2013 and examines trends in those data. A Regional Kendall Test was run to combine results from all wells to determine an overall regional trend in water level. Groundwater levels declined at an average rate of about 1.08 feet per year. Nitrate concentration trends show that 3 wells (18 percent) are increasing in nitrate concentration trend, 3 wells (18 percent) show a decreasing nitrate concentration trend, and 11 wells (64 percent) show no nitrate concentration trend. Six wells (35 percent) currently exceed the U.S. Environmental Protection Agency's maximum contaminant limit of 10 milligrams per liter for nitrate (nitrite plus nitrate, measured as nitrogen).

  12. Atoll groundwater movement and its response to climatic and sea-level fluctuations

    Science.gov (United States)

    Oberle, Ferdinand; Swarzenski, Peter; Storlazzi, Curt

    2017-01-01

    Groundwater resources of low-lying atoll islands are threatened due to short-term and long-term changes in rainfall, wave climate, and sea level. A better understanding of how these forcings affect the limited groundwater resources was explored on Roi-Namur in the Republic of the Marshall Islands. As part of a 16-month study, a rarely recorded island-overwash event occurred and the island’s aquifer’s response was measured. The findings suggest that small-scale overwash events cause an increase in salinity of the freshwater lens that returns to pre-overwash conditions within one month. The overwash event is addressed in the context of climate-related local sea-level change, which suggests that overwash events and associated degradations in freshwater resources are likely to increase in severity in the future due to projected rises in sea level. Other forcings, such as severe rainfall events, were shown to have caused a sudden freshening of the aquifer, with salinity levels retuning to pre-rainfall levels within three months. Tidal forcing of the freshwater lens was observed in electrical resistivity profiles, high-resolution conductivity, groundwater-level well measurements and through submarine groundwater discharge calculations. Depth-specific geochemical pore water measurements further assessed and confirmed the distinct boundaries between fresh and saline water masses in the aquifer. The identification of the freshwater lens’ saline boundaries is essential for a quantitative evaluation of the aquifers freshwater resources and help understand how these resources may be impacted by climate change and anthropogenic activities.

  13. Groundwater geochemistry near the storage sites of low-level radioactive waste: Implications for uranium migration

    Energy Technology Data Exchange (ETDEWEB)

    Gaskova, Olga L.; Boguslavsky, Anatoly E. [Institute of Geology and Mineralogy SB RAS, Ac. Koptyug prosp. 3, Novosibirsk 630090 (Russian Federation)

    2013-07-01

    This paper presents results of detailed sampling of groundwater and surface water near the storage sites of radioactive waste from the Electrochemical Plant ECP (Zelenogorsk, Krasnoyarsk region, Russia) and the Angarsk Electrolysis Chemical Complex AEC (Angarsk, Irkutsk region, Russia), both of which have produced enriched uranium since 1960's. The liquid (LRW) and solid (SRW) radioactive wastes belong to the category of low-level activity waste. The main result is that the uranium is below the recommended MPC for drinking waters in all types of groundwater around the sludge of ECP and AEC. But alkaline nitrate solutions have been penetrating and spreading into the aquifers under the LRW sludge pits. According to our calculations, redox conditions in the groundwater influenced by discharge are controlled by the couple NO{sub 3}{sup -}/NO{sub 2}{sup -} that facilitates U(VI) migration. The groundwater under SRW repositories is distinguished by its low mineralization and neutral pH. Co-contaminants, such as Mo, V, and Zr may serve as markers of techno-genous contamination in storage sites of the LRW sludge. (authors)

  14. Climate change impact on groundwater levels in the Guarani Aquifer outcrop zone

    Science.gov (United States)

    Melo, D. D.; Wendland, E.

    2013-12-01

    The unsustainable use of groundwater in many countries might cause water availability restrictions in the future. Such issue is likely to worsen due to predicted climate changes for the incoming decades. As numerous studies suggest, aquifers recharge rates will be affected as a result of climate change. The Guarani Aquifer System (GAS) is one of the most important transboundary aquifer in the world, providing drinkable water for millions of people in four South American countries (Brazil, Argentina, Uruguay and Paraguay). Considering the GAS relevance and how its recharge rates might be altered by climatic conditions anomalies, the objective of this work is to assess possible climate changes impacts on groundwater levels in this aquifer outcrop zone. Global Climate Models' (GCM) outputs were used as inputs in a transient flux groundwater model created using the software SPA (Simulation of Process in Aquifers), enabling groundwater table fluctuation to be evaluated under distinct climatic scenarios. Six monitoring wells, located in a representative basin (Ribeirão da Onça basin) inside a GAS outcrop zone (ROB), provided water table measurements between 2004 and 2011 to calibrate the groundwater model. Using observed climatic data, a water budget method was applied to estimate recharge in different types of land uses. Statistically downscaled future climate scenarios were used as inputs for that same recharge model, which provided data for running SPA under those scenarios. The results show that most of the GCMs used here predict temperature arises over 275,15 K and major monthly rainfall mean changes to take place in the dry season. During wet seasons, those means might experience around 50% decrease. The transient model results indicate that water table variations, derived from around 70% of the climate scenarios, would vary below those measured between 2004 and 2011. Among the thirteen GCMs considered in this work, only four of them predicted more extreme

  15. Forecasting monthly groundwater level fluctuations in coastal aquifers using hybrid Wavelet packet–Support vector regression

    Directory of Open Access Journals (Sweden)

    N. Sujay Raghavendra

    2015-12-01

    Full Text Available This research demonstrates the state-of-the-art capability of Wavelet packet analysis in improving the forecasting efficiency of Support vector regression (SVR through the development of a novel hybrid Wavelet packet–Support vector regression (WP–SVR model for forecasting monthly groundwater level fluctuations observed in three shallow unconfined coastal aquifers. The Sequential Minimal Optimization Algorithm-based SVR model is also employed for comparative study with WP–SVR model. The input variables used for modeling were monthly time series of total rainfall, average temperature, mean tide level, and past groundwater level observations recorded during the period 1996–2006 at three observation wells located near Mangalore, India. The Radial Basis function is employed as a kernel function during SVR modeling. Model parameters are calibrated using the first seven years of data, and the remaining three years data are used for model validation using various input combinations. The performance of both the SVR and WP–SVR models is assessed using different statistical indices. From the comparative result analysis of the developed models, it can be seen that WP–SVR model outperforms the classic SVR model in predicting groundwater levels at all the three well locations (e.g. NRMSE(WP–SVR = 7.14, NRMSE(SVR = 12.27; NSE(WP–SVR = 0.91, NSE(SVR = 0.8 during the test phase with respect to well location at Surathkal. Therefore, using the WP–SVR model is highly acceptable for modeling and forecasting of groundwater level fluctuations.

  16. Effects on the groundwater levels of the May-June 2012 Emilia seismic sequence

    Directory of Open Access Journals (Sweden)

    Marco Marcaccio

    2012-10-01

    Full Text Available A variety of phenomena were observed in the groundwaters in concomitance with the May-June 2012 seismic sequence that occurred in the Emilia Romagna area. In particular, phreatic wells close to the epicentral area were affected by a sudden increase in water level of up to 4 m. In some cases, the sands of aquifers were ejected outside wells, and >700 liquefaction phenomena were recorded [Bertolini and Fioroni 2012, this volume]. Some automatic stations of the regional well network recorded variations in well levels. These data can be considered useful to understand the relationships between seismic events and the local groundwaters [see also Italiano et al. 2012, this volume]. […] In 1976, a regional network composed of 330 wells was set up with the purpose of monitoring the groundwater levels using manual techniques. These data have been used for environmental purposes and for water management. In recent years, the monitoring network managed by Agenzia Regionale Prevenzione e Ambiente (ARPA has increased the number of wells (to about 600, and chemical analyses are also periodically carried out for environmental monitoring activities. In the past three years, an automatic monitoring network composed of 40 stations was set up and this has allowed the monitoring of the water levels and the temperatures, at a rate of one measure per hour, and to broadcast the data to the host center located in Bologna. […

  17. Recent trends in groundwater levels in a highly seasonal hydrological system: the Ganges-Brahmaputra-Meghna Delta

    Directory of Open Access Journals (Sweden)

    M. Shamsudduha

    2009-12-01

    Full Text Available Groundwater levels in shallow aquifers underlying Asian mega-deltas are characterized by strong seasonal variations associated with monsoon rainfall. To resolve trend and seasonal components in weekly groundwater levels in the Ganges-Brahmaputra-Meghna (GBM Delta, we apply a nonparametric seasonal-trend decomposition procedure (STL to observations compiled from 1985–2005 in Bangladesh. Seasonality dominates observed variance in groundwater levels but declining groundwater levels (>1 m/yr are detected in urban and peri-urban areas around Dhaka as well as in north-central, northwestern, and southwestern parts of the country (0.1–0.5 m/yr where intensive abstraction of groundwater is conducted for dry-season rice cultivation. Rising groundwater levels (0.5–2.5 cm/yr are observed in the estuarine and southern coastal regions. This novel application of the STL procedure reveals, for the first time, the unsustainability of irrigation supplied by shallow aquifers in some areas (e.g., High Barind Tract of the GBM Delta and the hydrological impact of potential seawater intrusion of coastal aquifers associated with sea-level rise. Our findings provide important insight into the hydrological impacts of groundwater-fed irrigation and sea-level rise in other Asian mega-deltas where monitoring data are limited.

  18. Recent trends in groundwater levels in a highly seasonal hydrological system: the Ganges-Brahmaputra-Meghna Delta

    Directory of Open Access Journals (Sweden)

    M. Shamsudduha

    2009-06-01

    Full Text Available Groundwater levels in shallow aquifers underlying Asian mega-deltas are characterized by strong seasonal variations associated with monsoon rainfall. To resolve trend and seasonal components in weekly groundwater levels in the Ganges-Brahmaputra-Meghna (GBM Delta, we apply a nonparametric seasonal-trend decomposition procedure (STL to observations compiled from 1985 to 2005 in Bangladesh. Seasonality dominates observed variance in groundwater levels but declining groundwater levels (>1 m/yr are detected in urban and peri-urban areas around Dhaka as well as in north-central, northwestern, and southwestern parts of the country (0.1 to 0.5 m/yr where intensive abstraction of groundwater is conducted for dry-season rice cultivation. Rising groundwater levels (0.5 to 2.5 cm/yr are observed in the estuarine and southern coastal regions. This novel application of the STL procedure reveals, for the first time, the unsustainability of irrigation supplied by shallow aquifers in some areas of the GBM Delta and the hydrological impact of seawater intrusion of coastal aquifers associated with sea-level rise. Our findings provide important insight into the hydrological impacts of groundwater-fed irrigation and sea-level rise in other Asian mega-deltas where monitoring data are limited.

  19. Characterizing the spatiotemporal variability of groundwater levels of alluvial aquifers in different settings using drought indices

    Science.gov (United States)

    Haas, Johannes Christoph; Birk, Steffen

    2017-05-01

    To improve the understanding of how aquifers in different alluvial settings respond to extreme events in a changing environment, we analyze standardized time series of groundwater levels (Standardized Groundwater level Index - SGI), precipitation (Standardized Precipitation Index - SPI), and river stages of three subregions within the catchment of the river Mur (Austria). Using correlation matrices, differences and similarities between the subregions, ranging from the Alpine upstream part of the catchment to its shallow foreland basin, are identified and visualized. Generally, river stages exhibit the highest correlations with groundwater levels, frequently affecting not only the wells closest to the river, but also more distant parts of the alluvial aquifer. As a result, human impacts on the river are transferred to the aquifer, thus affecting the behavior of groundwater levels. Hence, to avoid misinterpretation of groundwater levels in this type of setting, it is important to account for the river and human impacts on it. While the river is a controlling factor in all of the subregions, an influence of precipitation is evident too. Except for deep wells found in an upstream Alpine basin, groundwater levels show the highest correlation with a precipitation accumulation period of 6 months (SPI6). The correlation in the foreland is generally higher than that in the Alpine subregions, thus corresponding to a trend from deeper wells in the Alpine parts of the catchment towards more shallow wells in the foreland. Extreme events are found to affect the aquifer in different ways. As shown with the well-known European 2003 drought and the local 2009 floods, correlations are reduced under flood conditions, but increased under drought. Thus, precipitation, groundwater levels and river stages tend to exhibit uniform behavior under drought conditions, whereas they may show irregular behavior during floods. Similarly, correlations are found to be weaker in years with little

  20. Analysis of the applicability of geophysical methods and computer modelling in determining groundwater level

    Science.gov (United States)

    Czaja, Klaudia; Matula, Rafal

    2014-05-01

    The paper presents analysis of the possibilities of application geophysical methods to investigation groundwater conditions. In this paper groundwater is defined as liquid water flowing through shallow aquifers. Groundwater conditions are described through the distribution of permeable layers (like sand, gravel, fractured rock) and impermeable or low-permeable layers (like clay, till, solid rock) in the subsurface. GPR (Ground Penetrating Radar), ERT(Electrical Resistivity Tomography), VES (Vertical Electric Soundings) and seismic reflection, refraction and MASW (Multichannel Analysis of Surface Waves) belong to non - invasive, surface, geophysical methods. Due to differences in physical parameters like dielectric constant, resistivity, density and elastic properties for saturated and saturated zones it is possible to use geophysical techniques for groundwater investigations. Few programmes for GPR, ERT, VES and seismic modelling were applied in order to verify and compare results. Models differ in values of physical parameters such as dielectric constant, electrical conductivity, P and S-wave velocity and the density, layers thickness and the depth of occurrence of the groundwater level. Obtained results for computer modelling for GPR and seismic methods and interpretation of test field measurements are presented. In all of this methods vertical resolution is the most important issue in groundwater investigations. This require proper measurement methodology e.g. antennas with frequencies high enough, Wenner array in electrical surveys, proper geometry for seismic studies. Seismic velocities of unconsolidated rocks like sand and gravel are strongly influenced by porosity and water saturation. No influence of water saturation degree on seismic velocities is observed below a value of about 90% water saturation. A further saturation increase leads to a strong increase of P-wave velocity and a slight decrease of S-wave velocity. But in case of few models only the

  1. Influence of seasonal variations in sea level on the salinity regime of a coastal groundwater-fed wetland.

    Science.gov (United States)

    Wood, Cameron; Harrington, Glenn A

    2015-01-01

    Seasonal variations in sea level are often neglected in studies of coastal aquifers; however, they may have important controls on processes such as submarine groundwater discharge, sea water intrusion, and groundwater discharge to coastal springs and wetlands. We investigated seasonal variations in salinity in a groundwater-fed coastal wetland (the RAMSAR listed Piccaninnie Ponds in South Australia) and found that salinity peaked during winter, coincident with seasonal sea level peaks. Closer examination of salinity variations revealed a relationship between changes in sea level and changes in salinity, indicating that sea level-driven movement of the fresh water-sea water interface influences the salinity of discharging groundwater in the wetland. Moreover, the seasonal control of sea level on wetland salinity seems to override the influence of seasonal recharge. A two-dimensional variable density model helped validate this conceptual model of coastal groundwater discharge by showing that fluctuations in groundwater salinity in a coastal aquifer can be driven by a seasonal coastal boundary condition in spite of seasonal recharge/discharge dynamics. Because seasonal variations in sea level and coastal wetlands are ubiquitous throughout the world, these findings have important implications for monitoring and management of coastal groundwater-dependent ecosystems.

  2. Numerical Simulation of Changes in Groundwater-Level Induced by Earthquakes

    Science.gov (United States)

    Liu, Ching-Yi; Chia, Yeeping; Zheng, Ding-Qian

    2016-04-01

    Changes in groundwater level induced by earthquakes have been recorded worldwide. Sustained groundwater-level changes during earthquakes, primarily induced by the co-seismic strain due to fault displacement, are often observed in the confined aquifer. In the unconfined aquifer, sustained co-seismic changes can hardly be observed due to the rapid recovery of pore pressure change. In this study, field observation of co-seismic groundwater-level changes are showed. Also, the finite element software ABAQUS is used to simulate two-dimensional time-dependent pore pressure change in the aquifer due to fault displacement during earthquakes. Different physical properties are used to represent different types of aquifer. We adopted the 3-step method to simulate how earthquakes affect pore pressure in the 3 models, unconfined aquifer, confined aquifer and over-pressured confined layers. Results from the simulation gives us more details of how co-seismic and post-seismic pore pressure temporal changes are processed in different aquifers.

  3. Nitrogen and Oxygen Isotopes of Low-Level Nitrate in Groundwater For Environmental Forensics

    Science.gov (United States)

    Wang, Y.

    2009-05-01

    Sources of nitrate in water from human activities include fertilizers, animal feedlots, septic systems, wastewater treatment lagoons, animal wastes, industrial wastes and food processing wastes. Nitrogen and Oxygen isotopic analysis of nitrate in groundwater is essential to source identification and environmental forensics as nitrate from different sources carry distinctly different N and O isotopic compositions. Nitrate is extracted from groundwater samples and converted into AgNO3 using ion exchange techniques. The purified AgNO3 is then broken down into N2 and CO for N and O isotopic measurement. Since nitrate concentrations in natural ground waters are usually less than 2 mg/L, however, such method has been limited by minimum sample size it requires, in liters, which is highly nitrate concentration dependent. Here we report a TurboVap- Denitrifier method for N and O isotopic measurement of low-level dissolved nitrate, based on sample evaporation and isotopic analysis of nitrous oxide generated from nitrate by denitrifying bacteria that lack N2O- reductase activity. For most groundwater samples with mg/L-level of nitrate direct injection of water samples in mLs is applied. The volume of sample is adjusted according to its nitrate concentration to achieve a final sample size optimal for the system. For water samples with ug/L-level of nitrate, nitrate is highly concentrated using a TurboVap evaporator, followed by isotopic measurement with Denitrifier method. Benefits of TurboVap- Denitrifier method include high sensitivity and better precision in both isotopic data. This method applies to both freshwater and seawater. The analyses of isotopic reference materials in nitrate-free de-ionized water and seawater are included as method controls to correct for any blank effects. The isotopic data from groundwater and ocean profiles demonstrate the consistency of the data produced by the TurboVap-Denitrifier method.

  4. Forecasting the probability of future groundwater levels declining below specified low thresholds in the conterminous U.S.

    Science.gov (United States)

    Dudley, Robert W.; Hodgkins, Glenn A.; Dickinson, Jesse

    2017-01-01

    We present a logistic regression approach for forecasting the probability of future groundwater levels declining or maintaining below specific groundwater-level thresholds. We tested our approach on 102 groundwater wells in different climatic regions and aquifers of the United States that are part of the U.S. Geological Survey Groundwater Climate Response Network. We evaluated the importance of current groundwater levels, precipitation, streamflow, seasonal variability, Palmer Drought Severity Index, and atmosphere/ocean indices for developing the logistic regression equations. Several diagnostics of model fit were used to evaluate the regression equations, including testing of autocorrelation of residuals, goodness-of-fit metrics, and bootstrap validation testing. The probabilistic predictions were most successful at wells with high persistence (low month-to-month variability) in their groundwater records and at wells where the groundwater level remained below the defined low threshold for sustained periods (generally three months or longer). The model fit was weakest at wells with strong seasonal variability in levels and with shorter duration low-threshold events. We identified challenges in deriving probabilistic-forecasting models and possible approaches for addressing those challenges.

  5. Hydrogeologic map of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset represents the surface hydrogeology of an approximately 45,000 square-kilometer area of the Death Valley regional ground-water flow system...

  6. COVARIANCE CORRECTION FOR ESTIMATING GROUNDWATER LEVEL USING DETERMINISTIC ENSEMBLE KALMAN FILTER

    Directory of Open Access Journals (Sweden)

    J. Behmanesh

    2015-01-01

    Full Text Available The main problem in developing a groundwater model is to determine model parameters, particularly hydrogeologic coefficients, in a precise way. In this research, Deterministic Ensemble Kalman Filter (DEnKF is described as a modern sequential method for data assimilation and a localization scheme within the framework of DEnKF is applied. Najafabad aquifer (in Iran with area of 1150 km2, is modeled in the time window of Oct. 2000 to Sept. 2007 to obtain water table level data when its values of hydrogeologic coefficients calibrated and verified. DEnKF assimilated 45 observations of true run into the model with 2, 5, and 10 times of calibrated values of hydraulic conductivity and specific yield. This filter has been run both with and without use of localization. Results show easily-implemented localized DEnKF is favorably robust in groundwater flow modeling.

  7. Rational allocation of water resources based on ecological groundwater levels:a case study in Jinghui Irrigation District in China

    Science.gov (United States)

    Li, H.; Zhou, W. B.; Dong, Q. G.; Liu, B. Y.; Ma, C.

    2016-08-01

    Aimed at the hydrogeological environmental problems caused by over-exploitation and unreasonable utilization of water resources in Jinghui Irrigation District, this paper discusses the ecological groundwater level of the study area and establishes a three-layer optimal allocation model of water resources based on the theory of large scale systems. Then, the genetic algorithm method was employed to optimize the model and obtain the optimal allocation of crop irrigation schedule and water resources under the condition of a 75% assurance rate. Finally, the numerical simulation model of the groundwater was applied to analyze the balance of the groundwater on the basis of the optimal allocation scheme. The results show that the upper limitation of the ecological groundwater in Jinghui Irrigation District ranged from 1.8m to 4.2m, while the lower limitation level ranged from 8m to 28m. By 2020, the condition of the groundwater imbalance that results from adopting the optimal allocation scheme will be much better than that caused by current water utilization scheme. With the exception of only a few areas, the groundwater level in most parts of Jinghui Irrigation District will not exceed the lower limitation of ecological groundwater level.

  8. Comparison of different methods to assess natural backgrond levels in groundwater bodies in southern Europe

    Science.gov (United States)

    Preziosi, Elisabetta; Parrone, Daniele; Ghergo, Stefano; Ducci, Daniela; Sellerino, Mariangela; Condesso de Melo, Maria Teresa; Oliveira, Juana; Ribeiro, Luis

    2014-05-01

    The assessment of the natural background levels (NBLs) of a substance or element is important to distinguish anthropogenic pollution from contamination of natural origin in groundwater bodies. NBLs are the result of different atmospheric, geological, chemical and biological interaction processes during groundwater infiltration and circulation. Rainfall composition, water-rock interactions in both vadose and saturated zone, exchanges with other water bodies and residence time also contribute to determine the groundwater natural composition. Nowadays there are different methods to assess NBLs but the main concern is that they may provide different results. In the European legislative context, the Groundwater Directive (2006/118/EC) requests to EU Member States to derive appropriate threshold values (TV) for several potentially harmful substances, taking into account NBLs when necessary, in order to assess the chemical status of groundwater bodies. In the framework of a common project between Italy (CNR) and Portugal (FCT), several groundwater bodies were taken into account in different regions of Italy (Latium and Campania) and Portugal. The general objective is the definition of a sound comprehensive methodology for NBL assessment at groundwater body scale, suitable to different hydrogeological settings through comparing diverse case studies and different approaches. The Italian case studies are located in volcanic or volcano-sedimentary geological contexts, where high concentrations of substances such as As, F, Fe, Mn among others in groundwater are well known. The Portuguese case studies are located in carbonate and porous media aquifers. Several data sets were explored with the use of statistical as well as mathematical procedures in order to determine a threshold between natural and anthropogenic concentration. Today essentially two groups of methods are proposed, the first ascribed to the probability plots (PP method), the second based on the selection of the

  9. Spatial Assessment of Groundwater Quality Monitoring Wells Using Indicator Kriging and Risk Mapping, Amol-Babol Plain, Iran

    Directory of Open Access Journals (Sweden)

    Tahoora Sheikhy Narany

    2013-12-01

    Full Text Available The main aim of monitoring wells is to assess the conditions of groundwater quality in the aquifer system. An inappropriate distribution of sampling wells could produce insufficient or redundant data concerning groundwater quality. An optimal selection of representative monitoring well locations can be obtained by considering the natural and anthropogenic potential of pollution sources; the hydrogeological setting; and assessment of any existing data regarding monitoring networks. The main objective of this paper was to develop a new approach to identifying areas with a high risk of nitrate pollution for the Amol-Babol Plain, Iran. The indicator kriging method was applied to identify regions with a high probability of nitrate contamination using data obtained from 147 monitoring wells. The US-EPA DRASTIC method was then used in a GIS environment to assess groundwater vulnerability to nitrate contamination, and combined with data concerning the distribution of sources to produce a risk map. In the study area, around 3% of the total area has a strong probability of exceeding the nitrate threshold and a high–moderate risk of pollution, but is not covered adequately by sampling wells. However, the number of monitoring wells could be reduced in most parts of the study area to minimize redundant data and the cost of monitoring.

  10. Natural radioactivity levels in granitic plutons and groundwaters in Southeast part of Eskisehir, Turkey.

    Science.gov (United States)

    Orgün, Y; Altinsoy, N; Gültekin, A H; Karahan, G; Celebi, N

    2005-08-01

    The present work investigated the radioactivity level of the granitoid plutons and its effect on the groundwaters in the southeast part of Eskisehir. Fourteen granitic samples from the Kaymaz and Sivrihisar plutons and 11 groundwater samples from the near vicinity of the pluton were analyzed. The activity concentrations measured for (238)U and (232)Th ranged from 43.59+/-2 to 651.80+/-24 Bq/kg, and 51.16+/-3 to 351.94+/-13 Bq/kg, respectively. The activity concentrations obtained for (40)K varied from 418.50+/-17 to 1618.03+/-66 Bq/kg. The absorbed dose rates in air outdoors ranged from 87.14 to 531.81 nGy/h. All the results obtained from the Kaymaz pluton are higher than those from the Sivrihisar. The U (ave. 16.6 ppm) and Th (ave. 49.9 ppm) values of the Kaymaz pluton are higher than the average concentrations of the magmatic rocks of granitic composition. These results are consistent with high dose rates of the pluton. The gross-alpha activities in the groundwater samples ranged from 0.009 to 1.64 Bq/l and the gross-beta activities from 0.006 to 0.89 Bq/l. The highest gross-alpha value was found in the sample taken from near the Kaymaz pluton. The concentrations of (222)Rn varied from 0.060 to 0.557 Bq/l.

  11. Research on critical groundwater level under the threshold value of land subsidence in the typical region of Beijing

    Science.gov (United States)

    Jiang, Y.; Liu, J.-R.; Luo, Y.; Yang, Y.; Tian, F.; Lei, K.-C.

    2015-11-01

    Groundwater in Beijing has been excessively exploited in a long time, causing the groundwater level continued to declining and land subsidence areas expanding, which restrained the economic and social sustainable development. Long years of study show good time-space corresponding relationship between groundwater level and land subsidence. To providing scientific basis for the following land subsidence prevention and treatment, quantitative research between groundwater level and settlement is necessary. Multi-linear regression models are set up by long series factual monitoring data about layered water table and settlement in the Tianzhu monitoring station. The results show that: layered settlement is closely related to water table, water level variation and amplitude, especially the water table. Finally, according to the threshold value in the land subsidence prevention and control plan of China (45, 30, 25 mm), the minimum allowable layered water level in this region while settlement achieving the threshold value is calculated between -18.448 and -10.082 m. The results provide a reasonable and operable control target of groundwater level for rational adjustment of groundwater exploited horizon in the future.

  12. Application of a modified conceptual rainfall-runoff model to simulation of groundwater level in an undefined watershed.

    Science.gov (United States)

    Hong, Nian; Hama, Takehide; Suenaga, Yuichi; Aqili, Sayed Waliullah; Huang, Xiaowu; Wei, Qiaoyan; Kawagoshi, Yasunori

    2016-01-15

    Groundwater level simulation models can help ensure the proper management and use of urban and rural water supply. In this paper, we propose a groundwater level tank model (GLTM) based on a conceptual rainfall-runoff model (tank model) to simulate fluctuations in groundwater level. The variables used in the simulations consist of daily rainfall and daily groundwater level, which were recorded between April 2011 and March 2015 at two representative observation wells in Kumamoto City, Japan. We determined the best-fit model parameters by root-mean-square error through use of the Shuffled Complex Evolution-University of Arizona algorithm on a simulated data set. Calibration and validation results were evaluated by their coefficients of determination, Nash-Sutcliffe efficiency coefficients, and root-mean-square error values. The GLTM provided accurate results in both the calibration and validation of fluctuations in groundwater level. The split sample test results indicate a good reliability. These results indicate that this model can provide a simple approach to the accurate simulation of groundwater levels.

  13. Research on critical groundwater level under the threshold value of land subsidence in the typical region of Beijing

    Directory of Open Access Journals (Sweden)

    Y. Jiang

    2015-11-01

    Full Text Available Groundwater in Beijing has been excessively exploited in a long time, causing the groundwater level continued to declining and land subsidence areas expanding, which restrained the economic and social sustainable development. Long years of study show good time-space corresponding relationship between groundwater level and land subsidence. To providing scientific basis for the following land subsidence prevention and treatment, quantitative research between groundwater level and settlement is necessary. Multi-linear regression models are set up by long series factual monitoring data about layered water table and settlement in the Tianzhu monitoring station. The results show that: layered settlement is closely related to water table, water level variation and amplitude, especially the water table. Finally, according to the threshold value in the land subsidence prevention and control plan of China (45, 30, 25 mm, the minimum allowable layered water level in this region while settlement achieving the threshold value is calculated between −18.448 and −10.082 m. The results provide a reasonable and operable control target of groundwater level for rational adjustment of groundwater exploited horizon in the future.

  14. Groundwater-level change and evaluation of simulated water levels for irrigated areas in Lahontan Valley, Churchill County, west-central Nevada, 1992 to 2012

    Science.gov (United States)

    Smith, David W.; Buto, Susan G.; Welborn, Toby L.

    2016-09-14

    The acquisition and transfer of water rights to wetland areas of Lahontan Valley, Nevada, has caused concern over the potential effects on shallow aquifer water levels. In 1992, water levels in Lahontan Valley were measured to construct a water-table map of the shallow aquifer prior to the effects of water-right transfers mandated by the Fallon Paiute-Shoshone Tribal Settlement Act of 1990 (Public Law 101-618, 104 Stat. 3289). From 1992 to 2012, approximately 11,810 water-righted acres, or 34,356 acre-feet of water, were acquired and transferred to wetland areas of Lahontan Valley. This report documents changes in water levels measured during the period of water-right transfers and presents an evaluation of five groundwater-flow model scenarios that simulated water-level changes in Lahontan Valley in response to water-right transfers and a reduction in irrigation season length by 50 percent.Water levels measured in 98 wells from 2012 to 2013 were used to construct a water-table map. Water levels in 73 of the 98 wells were compared with water levels measured in 1992 and used to construct a water-level change map. Water-level changes in the 73 wells ranged from -16.2 to 4.1 feet over the 20-year period. Rises in water levels in Lahontan Valley may correspond to annual changes in available irrigation water, increased canal flows after the exceptionally dry and shortened irrigation season of 1992, and the increased conveyance of water rights transferred to Stillwater National Wildlife Refuge. Water-level declines generally occurred near the boundary of irrigated areas and may be associated with groundwater pumping, water-right transfers, and inactive surface-water storage reservoirs. The largest water-level declines were in the area near Carson Lake.Groundwater-level response to water-right transfers was evaluated by comparing simulated and observed water-level changes for periods representing water-right transfers and a shortened irrigation season in areas near Fallon

  15. Estimated 2008 groundwater potentiometric surface and predevelopment to 2008 water-level change in the Santa Fe Group aquifer system in the Albuquerque area, central New Mexico

    Science.gov (United States)

    Falk, Sarah E.; Bexfield, Laura M.; Anderholm, Scott K.

    2011-01-01

    The water-supply requirements of the Albuquerque metropolitan area of central New Mexico have historically been met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. Previous studies have indicated that the large quantity of groundwater withdrawal relative to recharge has resulted in water-level declines in the aquifer system throughout the metropolitan area. Analysis of the magnitude and pattern of water-level change can help improve understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies' efforts to minimize future water-level declines and improve sustainability. This report, prepared by the U.S. Geological Survey in cooperation with the Albuquerque Bernalillo County Water Utility Authority, presents the estimated groundwater potentiometric surface during winter (from December to March) of the 2008 water year and the estimated changes in water levels between predevelopment and water year 2008 for the production zone of the Santa Fe Group aquifer system in the Albuquerque and surrounding metropolitan and military areas. Hydrographs from selected wells are included to provide details of historical water-level changes. In general, water-level measurements used for this report were measured in small-diameter observation wells screened over short intervals and were considered to best represent the potentiometric head in the production zone-the interval of the aquifer, about 300 feet below land surface to 1,100 feet or more below land surface, in which production wells generally are screened. Water-level measurements were collected by various local and Federal agencies. The 2008 water year potentiometric surface map was created in a geographic information system, and the change in water-level elevation from predevelopment to water year 2008 was calculated. The 2008 water-level contours indicate that the general direction of

  16. Incidental Learning of Geospatial Concepts across Grade Levels: Map Overlay

    Science.gov (United States)

    Battersby, Sarah E.; Golledge, Reginald G.; Marsh, Meredith J.

    2006-01-01

    In this paper, the authors evaluate map overlay, a concept central to geospatial thinking, to determine how it is naively and technically understood, as well as to identify when it is leaner innately. The evaluation is supported by results from studies at three grade levels to show the progression of incidentally learned geospatial knowledge as…

  17. Incidental Learning of Geospatial Concepts across Grade Levels: Map Overlay

    Science.gov (United States)

    Battersby, Sarah E.; Golledge, Reginald G.; Marsh, Meredith J.

    2006-01-01

    In this paper, the authors evaluate map overlay, a concept central to geospatial thinking, to determine how it is naively and technically understood, as well as to identify when it is leaner innately. The evaluation is supported by results from studies at three grade levels to show the progression of incidentally learned geospatial knowledge as…

  18. Statistical mapping of zones of focused groundwater/surface-water exchange using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Mwakanyamale, Kisa; Day-Lewis, Frederick D.; Slater, Lee D.

    2013-01-01

    Fiber-optic distributed temperature sensing (FO-DTS) increasingly is used to map zones of focused groundwater/surface-water exchange (GWSWE). Previous studies of GWSWE using FO-DTS involved identification of zones of focused GWSWE based on arbitrary cutoffs of FO-DTS time-series statistics (e.g., variance, cross-correlation between temperature and stage, or spectral power). New approaches are needed to extract more quantitative information from large, complex FO-DTS data sets while concurrently providing an assessment of uncertainty associated with mapping zones of focused GSWSE. Toward this end, we present a strategy combining discriminant analysis (DA) and spectral analysis (SA). We demonstrate the approach using field experimental data from a reach of the Columbia River adjacent to the Hanford 300 Area site. Results of the combined SA/DA approach are shown to be superior to previous results from qualitative interpretation of FO-DTS spectra alone.

  19. The thermal consequences of river-level variations in an urban groundwater body highly affected by groundwater heat pumps.

    Science.gov (United States)

    García-Gil, Alejandro; Vázquez-Suñe, Enric; Schneider, Eduardo Garrido; Sánchez-Navarro, José Ángel; Mateo-Lázaro, Jesús

    2014-07-01

    The extensive implementation of ground source heat pumps in urban aquifers is an important issue related to groundwater quality and the future economic feasibility of existent geothermal installations. Although many cities are in the immediate vicinity of large rivers, little is known about the thermal river-groundwater interaction at a kilometric-scale. The aim of this work is to evaluate the thermal impact of river water recharges induced by flood events into an urban alluvial aquifer anthropogenically influenced by geothermal exploitations. The present thermal state of an urban aquifer at a regional scale, including 27 groundwater heat pump installations, has been evaluated. The thermal impacts of these installations in the aquifer together with the thermal impacts from "cold" winter floods have also been spatially and temporally evaluated to ensure better geothermal management of the aquifer. The results showed a variable direct thermal impact from 0 to 6 °C depending on the groundwater-surface water interaction along the river trajectory. The thermal plumes far away from the riverbed also present minor indirect thermal impacts due to hydraulic gradient variations. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Effectiveness of basin morphometry, remote sensing, and applied geosciences on groundwater recharge potential mapping: a comparative study within a small watershed

    Science.gov (United States)

    Roy, Suvendu; Sahu, Abhay Sankar

    2016-06-01

    A multidisciplinary approach using the integrated field of geosciences (e.g., geomorphology, geotectonics, geophysics, and hydrology) is established to conduct groundwater recharge potential mapping of the Kunur River Basin, India. The relative mean error (RME) calculation of the results of three applied techniques and water table data from twenty-four observation wells in the basin over the 2000-2010 period are presented. Nine subbasins were identified and ranked for the RME calculation, where the observation wells-based ranking was taken as standard order for comparison. A linear model has been developed using six factors (drainage density, surface slope, ruggedness index, lineament density, Bouguer gravity anomaly, and potential maximum water retention capacity) and a grid-wise weighted index. In a separate comparative approach, the sub-basin and grid-wise analyses have been conducted to identify the suitable spatial unit for watershed level hydrological modeling.

  1. Groundwater Governance in the United States: Common Priorities and Challenges.

    Science.gov (United States)

    Megdal, Sharon B; Gerlak, Andrea K; Varady, Robert G; Huang, Ling-Yee

    2015-01-01

    Groundwater is a critical component of the water supply for agriculture, urban areas, industry, and ecosystems, but managing it is a challenge because groundwater is difficult to map, quantify, and evaluate. Until recently, study and assessment of governance of this water resource has been largely neglected. A survey was developed to query state agency officials about the extent and scope of groundwater use, groundwater laws and regulations, and groundwater tools and strategies. Survey responses revealed key findings: states' legal frameworks for groundwater differ widely in recognizing the hydrologic connection between surface water and groundwater, the needs of groundwater-dependent ecosystems, and the protection of groundwater quality; states reported a range in capacity to enforce groundwater responsibilities; and states have also experienced substantial changes in groundwater governance in the past few decades. Overall, groundwater governance across the United States is fragmented. States nevertheless identified three common priorities for groundwater governance: water quality and contamination, conflicts between users, and declining groundwater levels. This survey represents an initial step in a broader, continuing effort to characterize groundwater governance practices in the United States.

  2. Effects of Heterogeneity and Uncertainties in Sources and Initial and Boundary Conditions on Spatiotemporal Variations of Groundwater Levels

    Science.gov (United States)

    Zhang, Y. K.; Liang, X.

    2014-12-01

    Effects of aquifer heterogeneity and uncertainties in source/sink, and initial and boundary conditions in a groundwater flow model on the spatiotemporal variations of groundwater level, h(x,t), were investigated. Analytical solutions for the variance and covariance of h(x, t) in an unconfined aquifer described by a linearized Boussinesq equation with a white noise source/sink and a random transmissivity field were derived. It was found that in a typical aquifer the error in h(x,t) in early time is mainly caused by the random initial condition and the error reduces as time goes to reach a constant error in later time. The duration during which the effect of the random initial condition is significant may last a few hundred days in most aquifers. The constant error in groundwater in later time is due to the combined effects of the uncertain source/sink and flux boundary: the closer to the flux boundary, the larger the error. The error caused by the uncertain head boundary is limited in a narrow zone near the boundary but it remains more or less constant over time. The effect of the heterogeneity is to increase the variation of groundwater level and the maximum effect occurs close to the constant head boundary because of the linear mean hydraulic gradient. The correlation of groundwater level decreases with temporal interval and spatial distance. In addition, the heterogeneity enhances the correlation of groundwater level, especially at larger time intervals and small spatial distances.

  3. Mapping selected trace elements and major ions, 2000-2012, Mojave River and Morongo groundwater basins, southwestern Mojave Desert, San Bernardino County, California

    Science.gov (United States)

    Metzger, Loren F.; Landon, Matthew K.; House, Sally F.; Olsen, Lisa D.

    2015-01-01

    The population of the Mojave River and Morongo groundwater basins has grown rapidly during the last several decades, increasing from an estimated population of almost 273,000 in 1990 (Mojave Water Agency, 2004) to more than 453,000 in 2010 (Mojave Water Agency, 2014). Groundwater is the primary source of potable water in both basins (Mojave Water Agency, 2014). Previous studies noted elevated concentrations of several trace elements, nitrate, and total dissolved solids in groundwater in portions of the two basins (Christensen and Fields-Garland, 2001; Ball and Izbicki, 2004; Izbicki and others, 2008; Mathany and Belitz, 2009; Wright and Belitz, 2010; Dawson and Belitz, 2012; and Izbicki and others, 2012). Since 2000, the U.S. Geological Survey (USGS) has collected water-quality data annually from a network of wells and has provided quality-assurance for Mojave Water Agency (MWA) data that are stored in the USGS National Water Information System (NWIS) database. The new data and results from the joint State of California and USGS Groundwater Ambient Monitoring and Assessment (GAMA) program assessments of regional water quality (these data are also stored in NWIS), in combination with ongoing MWA/USGS groundwater-quality monitoring provide a timely opportunity for mapping of groundwater quality in the Mojave River and Morongo groundwater basins. The purpose of this report is to provide maps and time-series plots of concentrations of selected water-quality constituents (arsenic, boron, chromium-6, total chromium, dissolved oxygen, fluoride, iron, manganese, nitriate plus nitrite as nitrogen, total dissolved solids, uranium, and vanadium) in the Mojave River and Morongo groundwater basins using data collected by the USGS and MWA from 2000 to 2012. These maps and plots can be accessed on this website.

  4. Global Groundwater related Risk Indicators: quantifying groundwater stress and groundwater table decline (1990-2010) at global scale

    Science.gov (United States)

    Faneca Sanchez, Marta; Sutanudjaja, Edwin; Kuijper, Marijn; Bierkens, Marc

    2016-04-01

    Groundwater is an invisible but indispensable resource for the economic development of many countries. Due to the need for this resource, in many cases it is exploited under severe pressure and the exploitation can become not sustainable. The non-sustainable exploitation of water is a well-known problem on both regional and global scales. However, most currently-available assessments on water stress still mostly focus on surface water and on water balances. In this work, we presented two global maps of groundwater risk indicators: an updated version of the groundwater stress (Gleeson et al., 2011, DOI: 10.1038/nature11295) and an indicator on groundwater table decline for the period 1990-2010. To calculate both indicators, we used the updated PCR-GLOBWB model output at 5 arcmin resolution (about 10 km at the equator), that is extended with an offline coupling to a global groundwater MODFLOW model. PCR-GLOBWB simulates daily river discharge and groundwater recharge, as well as surface water and groundwater abstraction rates. The latter are estimated internally within the model based on the simulation of their availabilities and water demands for irrigation and other sectors. The daily output of PCR-GLOBWB would then be aggregated to the monthly resolution and used to force the MODFLOW groundwater model resolving spatio-temporal groundwater table dynamics, incorporating the simulated groundwater abstraction of PCR-GLOBWB. Using the PCR-GLOBWB and MODFLOW simulation results from the period 1990-2010, we then quantified groundwater stress and assessed the groundwater table decline. Results are presented on four different spatial scales: 5 arcmin pixel, drainage/sub-catchment unit, state level, and major aquifer unit. The maps clearly show where groundwater is under stress, where there is a trend in the drop of the groundwater table, the slope of the drop and the significance of it.

  5. Topographic reference points in California for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set is a compilation of reference points representing surface-water features, ground-water levels, and topographic settings in California that...

  6. Topographic reference points in California for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set is a compilation of reference points representing surface-water features, ground-water levels, and topographic settings in California that were...

  7. Topographic reference points in Nevada for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set is a compilation of reference points representing surface-water features, ground-water levels, and topographic settings in Nevada that were...

  8. Geomorphic interaction among climate, sea levels and karst groundwater: the Taranto area (South of Italy)

    Science.gov (United States)

    Spilotro, Giuseppe; Fidelibus, Maria Dolores; Argentiero, Ilenia; Pellicani, Roberta; Parisi, Alessandro; Di Modugno, Antonella

    2017-04-01

    The area of Taranto (Apulia region, Italy) has an extraordinary environmental and landscape value, which derives from its specific geological, geomorphological and hydrogeological conditions: they represent the effect of a complex mechanism of interaction in the geological time among the sea, its level variations and stands driven by climate changes, karst groundwater and the geo lithological frame. The knowledge of this interaction spans over two very different time duration: the first is subsequent to the sedimentary pleistocenic deposition and diagenesis and lasts until the late Holocene; the second spans over a more limited time durations, from the LIA until today, and its knowledge is mainly based on hystorical topographic records and reports. The general geological and stratigraphical setting is represented by marine deposits, which fill the Bradanic Trough, shaped in the upper part as marine terraces bordering the W and SW side of the Murgian carbonate platform (Apulia, South of Italy) as well. This latter constitutes an important karst hydro-structure, fed by precipitation, bordered on the opposite side of the Bradanic Trough by the Adriatic Sea. Fresh groundwater hosted in the huge coastal aquifer freely flows towards the Adriatic coast, while on the opposite W-NW side, the continuous confinement by the impermeable filling of the trough, forces the underground drainage of the aquifer towards the Ionian Sea just in the Taranto area. The overall flow rate of the groundwater through submarine and subaerial coastal springs, according to the current sea level, is significant and currently estimated in about 18 m3/sec. Climate changes have forced over geological time, but also in shorter periods, sea level changes and stands, consequently correlated to groundwater levels. This allowed genesis of selected karst levels, of regional extension, both at the surface or underground, which arise as typical forms, namely polje and karst plane inland, terraces on the sea

  9. Effects of groundwater levels and headwater wetlands on streamflow in the Charlie Creek basin, Peace River watershed, west-central Florida

    Science.gov (United States)

    Lee, T.M.; Sacks, L.A.; Hughes, J.D.

    2010-01-01

    The Charlie Creek basin was studied from April 2004 to December 2005 to better understand how groundwater levels in the underlying aquifers and storage and overflow of water from headwater wetlands preserve the streamflows exiting this least-developed tributary basin of the Peace River watershed. The hydrogeologic framework, physical characteristics, and streamflow were described and quantified for five subbasins of the 330-square mile Charlie Creek basin, allowing the contribution of its headwaters area and tributary subbasins to be separately quantified. A MIKE SHE model simulation of the integrated surface-water and groundwater flow processes in the basin was used to simulate daily streamflow observed over 21 months in 2004 and 2005 at five streamflow stations, and to quantify the monthly and annual water budgets for the five subbasins including the changing amount of water stored in wetlands. Groundwater heads were mapped in Zone 2 of the intermediate aquifer system and in the Upper Floridan aquifer, and were used to interpret the location of artesian head conditions in the Charlie Creek basin and its relation to streamflow. Artesian conditions in the intermediate aquifer system induce upward groundwater flow into the surficial aquifer and help sustain base flow which supplies about two-thirds of the streamflow from the Charlie Creek basin. Seepage measurements confirmed seepage inflow to Charlie Creek during the study period. The upper half of the basin, comprised largely of the Upper Charlie Creek subbasin, has lower runoff potential than the lower basin, more storage of runoff in wetlands, and periodically generates no streamflow. Artesian head conditions in the intermediate aquifer system were widespread in the upper half of the Charlie Creek basin, preventing downward leakage from expansive areas of wetlands and enabling them to act as headwaters to Charlie Creek once their storage requirements were met. Currently, the dynamic balance between wetland

  10. Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

    Directory of Open Access Journals (Sweden)

    F. Jørgensen

    2012-07-01

    Full Text Available Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark, a combination of an airborne electromagnetic survey (performed with the SkyTEM system, a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m which gives a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt/freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and their control on the groundwater salinity distribution is assessed.

  11. Water-Level Monitoring Plan for the Hanford Groundwater Monitoring Project

    Energy Technology Data Exchange (ETDEWEB)

    D.R. Newcomer; J.P. McDonald; M.A. Chamness

    1999-09-30

    This document presents the water-level monitoring plan for the Hanford Groundwater Monitoring Project, conducted by the Pacific Northwest National Laboratory (PNNL). Water-level monitoring of the groundwater system beneath the Hanford Site is performed to fulfill the requirements of various state and federal regulations, orders, and agreements. The primary objective of this monitoring is to determine groundwater flow rates and directions. To meet this and other objectives, water-levels are measured annually in monitoring wells completed within the unconfined aquifer system, the upper basalt-confined aquifer system, and in the lower basalt-confined aquifers for surveillance monitoring. At regulated waste units, water levels are taken monthly, quarterly, semi-annually, or annually, depending on the hydrogeologic conditions and regulatory status of a given site. The techniques used to collect water-level data are described in this document along with the factors that affect the quality of the data and the strategies employed by the project to minimize error in the measurement and interpretation of water levels. Well networks are presented for monitoring the unconfined aquifer system, the upper basalt-confined aquifer system, and the lower basalt-confined aquifers, all at a regional scale (surveillance monitoring), as well as the local-scale well networks for each of the regulated waste units studied by this project (regulated-unit monitoring). The criteria used to select wells for water-table monitoring are discussed. It is observed that poor well coverage for surveillance water-table monitoring exists south and west of the 200-West Area, south of the 100-F Area, and east of B Pond and the Treated Effluent Disposal Facility (TEDF). This poor coverage results from a lack of wells suitable for water-table monitoring, and causes uncertainty in representation of the regional water-table in these areas. These deficiencies are regional in scale and apply to regions outside

  12. Groundwater monitoring in the Savannah River Plant Low Level Waste Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.

    1983-12-31

    This document describes chemical mechanisms that may affect trace-level radionuclide migration through acidic sandy clay soils in a humid environment, and summarizes the extensive chemical and radiochemical analyses of the groundwater directly below the SRP Low-Level Waste (LLW) Burial Ground (643-G). Anomalies were identified in the chemistry of individual wells which appear to be related to small amounts of fission product activity that have reached the water table. The chemical properties which were statistically related to trace level transport of Cs-137 and Sr-90 were iron, potassium, sodium and calcium. Concentrations on the order of 100 ppM appear sufficient to affect nuclide migration. Several complexation mechanisms for plutonium migration were investigated.

  13. Wavelet coupled MARS and M5 Model Tree approaches for groundwater level forecasting

    Science.gov (United States)

    Rezaie-balf, Mohammad; Naganna, Sujay Raghavendra; Ghaemi, Alireza; Deka, Paresh Chandra

    2017-10-01

    In this study, two different machine learning models, Multivariate Adaptive Regression Splines (MARS) and M5 Model Trees (MT) have been applied to simulate the groundwater level (GWL) fluctuations of three shallow open wells within diverse unconfined aquifers. The Wavelet coupled MARS and MT hybrid models were developed in an attempt to further increase the GWL forecast accuracy. The Discrete Wavelet Transform (DWT) which is particularly effective in dealing with non-stationary time-series data was employed to decompose the input time series into various sub-series components. Historical data of 10 years (August-1996 to July-2006) comprising monthly groundwater level, rainfall, and temperature were used to calibrate and validate the models. The models were calibrated and tested for one, three and six months ahead forecast horizons. The wavelet coupled MARS and MT models were compared with their simple counterpart using standard statistical performance evaluation measures such as Root Mean Square Error (RMSE), Normalized Nash-Sutcliffe Efficiency (NNSE) and Coefficient of Determination (R2) . The wavelet coupled MARS and MT models developed using multi-scale input data performed better compared to their simple counterpart and the forecast accuracy of W-MARS models were superior to that of W-MT models. Specifically, the DWT offered a better discrimination of non-linear and non-stationary trends that were present at various scales in the time series of the input variables thus crafting the W-MARS models to provide more accurate GWL forecasts.

  14. Microbial Community-Level Physiological Profiles (CLPP) and herbicide mineralization potential in groundwater affected by agricultural land use

    DEFF Research Database (Denmark)

    Janniche, Gry Sander; Spliid, Henrik; Albrechtsen, Hans-Jørgen

    2012-01-01

    Diffuse groundwater pollution from agricultural land use may impact the microbial groundwater community, which was investigated as Community-Level Physiological Profiles (CLPP) using EcoPlate™. Water was sampled from seven piezometers and a spring in a small agricultural catchment with diffuse...... herbicide and nitrate pollution. Based on the Shannon–Wiener and Simpson's diversity indices the diversity in the microbial communities was high. The response from the EcoPlates™ showed which substrates support groundwater bacteria, and all 31 carbon sources were utilized by organisms from at least one......-galacturonic acid, tween 40, and 4-hydroxy benzoic acid as substrates, whereas none preferred 2-hydroxy benzoic acid, α-d-lactose, d,l-α-glycerol phosphate, α-ketobutyric acid, l-threonine and glycyl-l-glutamic acid. Principal Component Analysis of the CLPP's clustered the most agriculturally affected groundwater...

  15. Groundwater level response in U.S. Principal Aquifers to natural climate variability on interannual to multidecadal timescales

    Science.gov (United States)

    Velasco, E.; Gurdak, J. J.; Dickinson, J.; Hanson, R. T.; Ferré, T. P. A.; Maurer, E. P.

    2014-12-01

    Natural climate variability on interannual to multidecadal timescales are important controls on precipitation, drought, evapotranspiration, streamflow, and groundwater recharge. Climate variability can also augment or diminish human stresses on water resources. Thus, understanding climate variability has particular relevance for groundwater management. Findings will be presented from a national scale study of groundwater level response to natural climate variability in principal aquifers (PAs) of the U.S., including the California Coastal Basin, Rio Grande, Coastal Lowlands, Mississippi Embayment, Floridan, and Glacial aquifer systems. We use the U.S. Geological Survey hydroclimatic analysis toolkit HydroClimATe to perform singular spectrum analysis and identify quasi-periodic signals in precipitation and groundwater time series that are coincident with the Arctic Oscillation (AO) (6-12 mo cycle), Pacific/North American oscillation (PNA) (management and planning decisions about the locations, cost effectiveness, and optimal time periods for conjunctive use strategies.

  16. Water level observations from Unmanned Aerial Vehicles (UAVs) for improving probabilistic estimations of interaction between rivers and groundwater

    Science.gov (United States)

    Bandini, Filippo; Butts, Michael; Vammen Jacobsen, Torsten; Bauer-Gottwein, Peter

    2016-04-01

    efficient global Markov Chain Monte Carlo (MCMC) in high-dimensional spaces. Calibration against water level has demonstrated a significant improvement of the estimation of the exchange flow between groundwater and river branch. Groundwater flux and direction are now better simulated. Reliability and sharpness of the probabilistic forecasts are assessed with the sharpness, the interval skill score (ISS) of the 95{%} confidence interval, and with the root mean square error (RMSE) of the maximum a posteriori probability (MAP). The binary outcome (either gaining or loosing stream) of the flow direction is assessed with Brier score (BS). After water level calibration the sharpness of the estimations is approximately doubled with respect to the model calibrated only against discharge, ISS has improved from 2.4-7to 7.8-8 m^3/s\\cdot m, RMSE from 9.2-8 to 2.4-8 m^3/s\\cdot m^and BS is halved from 0.58 to 0.25.

  17. A plan for study of hexavalent chromium, CR(VI) in groundwater near a mapped plume, Hinkley, California, 2016

    Science.gov (United States)

    Izbicki, John A.; Groover, Krishangi

    2016-01-22

    The Pacific Gas and Electric Company (PG&E) Hinkley compressor station, in the Mojave Desert 80 miles northeast of Los Angeles, is used to compress natural gas as it is transported through a pipeline from Texas to California. Between 1952 and 1964, cooling water used at the compressor station was treated with a compound containing chromium to prevent corrosion. After cooling, the wastewater was discharged to unlined ponds, resulting in contamination of soil and groundwater in the underlying alluvial aquifer (Lahontan Regional Water Quality Control Board, 2013). Since 1964, cooling-water management practices have been used that do not contribute chromium to groundwater.In 2007, a PG&E study of the natural background concentrations of hexavalent chromium, Cr(VI), in groundwater estimated average concentrations in the Hinkley area to be 1.2 micrograms per liter (μg/L), with a 95-percent upper-confidence limit of 3.1 μg/L (CH2M-Hill, 2007). The 3.1 μg/L upper-confidence limit was adopted by the Lahontan Regional Water Quality Control Board (RWQCB) as the maximum background concentration used to map the plume extent. In response to criticism of the study’s methodology, and an increase in the mapped extent of the plume between 2008 and 2011, the Lahontan RWQCB (Lahontan Regional Water Quality Control Board, 2012) agreed that the 2007 PG&E background-concentration study be updated.The purpose of the updated background study is to evaluate the presence of natural and man-made Cr(VI) near Hinkley, Calif. The study also is to estimate natural background Cr(VI) concentrations in the aquifer upgradient and downgradient from the mapped Cr(VI) contamination plume, as well as in the plume and near its margins. The study was developed by the U.S. Geological Survey (USGS) in collaboration with a technical working group (TWG) composed of community members, the Independent Review Panel (IRP) Manager (Project Navigator, Ltd.), the Lahontan RWQCB, PG&E, and consultants for PG&E.&E.

  18. Offshore Dredger Sounds: Source Levels, Sound Maps, and Risk Assessment.

    Science.gov (United States)

    de Jong, Christ A F; Ainslie, Michael A; Heinis, Floor; Janmaat, Jeroen

    2016-01-01

    The underwater sound produced during construction of the Port of Rotterdam harbor extension (Maasvlakte 2) was measured, with emphasis on the contribution of the trailing suction hopper dredgers during their various activities: dredging, transport, and discharge of sediment. Measured source levels of the dredgers, estimated source levels of other shipping, and time-dependent position data from a vessel-tracking system were used as input for a propagation model to generate dynamic sound maps. Various scenarios were studied to assess the risk of possible effects of the sound from dredging activities on marine fauna, specifically on porpoises, seals, and fish.

  19. Purification and Detection of 39Ar in Groundwater Samples via Low-Level Counting

    Science.gov (United States)

    Mace, E. K.; Aalseth, C.; Brandenberger, J. M.; Humble, P.; Panisko, M.; Seifert, A.; Williams, R. M.

    2015-12-01

    Argon-39 can be used as a radiotracer to age-date groundwater aquifers to study recharge rates and to better understand the mean residence time, or age distributions, of groundwater. Argon-39 (with a half-life of 269 years) is created in the atmosphere by cosmic rays interacting with argon in the air (primarily 40Ar). The use of 39Ar as a radiotracer fills a gap in the age dating range which is currently covered by 3H/3He or 85Kr (1000 years); 39Ar fills the intermediate time scale range from 50-1000 years where the previously established radiotracers are not adequate. We will introduce the process for purifying and detecting 39Ar in ground water using ultra-low-background proportional counters (ULBPCs) at the shallow underground laboratory at Pacific Northwest National Laboratory. Argon-39 is detected through direct beta counting using ULBPCs loaded with a mixture of geologic argon (extracted from a carbon dioxide well with no measureable 39Ar activity) and methane, which enhances the sensitivity for 39Ar measurements. The ULBPCs have been shown to have a background count rate of 148 counts per day (cpd) in the energy range 3-400 keV when filled with 10 atm of P-10 counting gas (90% geologic Ar, 10% CH4). Initial demonstration samples were collected from groundwater aquifers in Fresno, California supported by the United States Geological Survey (USGS). A discussion of the sampling technique to degas the water from these wells and to then purify it for counting will be presented. In order to quantify the 39Ar contribution in the groundwater samples, the ULBPCs were characterized to determine two components: 1) the detector efficiency to modern levels of 39Ar, and 2) the remaining detector background (using geologic sourced argon which is free from 39Ar - no measureable 39Ar activity). These characterization results will be presented along with a discussion of the quantification of the 39Ar age of the demonstration measurements.

  20. Climate change impact on groundwater levels: ensemble modelling of extreme values

    Directory of Open Access Journals (Sweden)

    J. Kidmose

    2012-06-01

    Full Text Available This paper presents a first attempt to estimate future groundwater levels by applying extreme value statistics on predictions from a hydrological model. Climate for the future period, 2081–2100, are represented by projections from nine combinations of three global climate models and six regional climate models, and downscaled with two different methods. An integrated surface water/groundwater model is forced with precipitation, temperature, and evapotranspiration from the 18 model – and downscaling combinations. Extreme value analyses are performed on the hydraulic head changes from a control period (1991–2010 to the future period for the 18 combinations. Hydraulic heads for return periods of 21, 50 and 100 yr (T21–100 are estimated. Three uncertainty sources are evaluated; climate models, downscaling and extreme value statistics. Of these sources, downscaling dominates for the higher return periods of 50 and 100 yr, whereas uncertainty from climate models and downscaling are similar for lower return periods. Uncertainty from the extreme value statistics only contribute up to around 10% of the uncertainty from the three sources.

  1. DETERMINATION OF THE GROUND-WATER LEVEL BY MODERN NON-DISTRUCTIVE METHODS (GPR TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    I. C. NICU

    2011-03-01

    Full Text Available Determination of the ground-water level by modern non-dis¬tructive methods (ground-penetrating radar technology. Ground Penetrating Radar (GPR is now a well-accepted geophysical technique, which unfortunately in our country its less used. Historically, the development of GPR comes from the use of radio echosounding to determine ice thickness and it was only a short step to enlarge the domain of research such as permafrost, geological investigation (bedrock, sedimentology, environmental assessment and hydrogeophysical studies (under-ground water location, soil water content. The GPR method measures the travel time of electromagnetic impulses in subsurface materials. An impulse radar system radiates repetitive electromagnetic impulses into the soil. A bandwidth antenna is usually placed in close proximity and electromagnetic coupled to the ground surface. It detects and measures the depth of reflecting discontinuities in subsurface soils and other earth materials to within a few centimeters depending of antenna frequency. For over 30 years, GPR has been used extensively for hydropedological investigations. Our research aims to determine the groundwater to estimate the degree of evolution of hydro-geomorphological processes.

  2. Space-Time Modelling of Groundwater Level Using Spartan Covariance Function

    Science.gov (United States)

    Varouchakis, Emmanouil; Hristopulos, Dionissios

    2014-05-01

    Geostatistical models often need to handle variables that change in space and in time, such as the groundwater level of aquifers. A major advantage of space-time observations is that a higher number of data supports parameter estimation and prediction. In a statistical context, space-time data can be considered as realizations of random fields that are spatially extended and evolve in time. The combination of spatial and temporal measurements in sparsely monitored watersheds can provide very useful information by incorporating spatiotemporal correlations. Spatiotemporal interpolation is usually performed by applying the standard Kriging algorithms extended in a space-time framework. Spatiotemoral covariance functions for groundwater level modelling, however, have not been widely developed. We present a new non-separable theoretical spatiotemporal variogram function which is based on the Spartan covariance family and evaluate its performance in spatiotemporal Kriging (STRK) interpolation. The original spatial expression (Hristopulos and Elogne 2007) that has been successfully used for the spatial interpolation of groundwater level (Varouchakis and Hristopulos 2013) is modified by defining the following space-time normalized distance h = °h2r-+-α h2τ, hr=r- ξr, hτ=τ- ξτ; where r is the spatial lag vector, τ the temporal lag vector, ξr is the correlation length in position space (r) and ξτ in time (τ), h the normalized space-time lag vector, h = |h| is its Euclidean norm of the normalized space-time lag and α the coefficient that determines the relative weight of the time lag. The space-time experimental semivariogram is determined from the biannual (wet and dry period) time series of groundwater level residuals (obtained from the original series after trend removal) between the years 1981 and 2003 at ten sampling stations located in the Mires hydrological basin in the island of Crete (Greece). After the hydrological year 2002-2003 there is a significant

  3. Mapping of groundwater quality in the Turonian aquifer of Oum Er-Rabia Basin, Morocco: a case study

    Science.gov (United States)

    Ettazarini, Said

    2006-08-01

    This study takes the groundwater of the Moroccan limestone aquifer of Oum Er-Rabia as an example of statistical and cartographical approaches in water resources management. Statistical analyses based on frequency distribution and PCA methods revealed the homogeneity of waters with the existence of abnormal points and have helped to assess correlations between the studied variables. The mapping approach illustrated that waters are influenced by the lithology of the surrounding rocks and are of Ca Mg HCO3, Ca Mg Cl SO4, and mixed types according to the Piper classification. The quality of water is of high to medium, north of the basin, but it is of medium to bad, NE and south, due to excessive contents of chloride, sulfate and nitrate. According to the US Salinity Laboratory classification, water used for irrigation in the eastern and the southern parts of the basin should take into consideration the drainage conditions, the nature of plants and the addition of gypsum doses.

  4. Physiological response of natural plants to the change of groundwater level in the lower reaches of Tarim River,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    CHEN Yaning; LI Weihong; CHEN Yapeng; ZHANG Hongfeng; ZHUANG Li

    2004-01-01

    Based on the analysis of the three-year (2000-2002) monitoring data of the four times intermittent stream water conveyance to the lower reaches of Tarim River where the stream flow was dried up for more than 30 years and the measurement of PRO, SOD and POD in plants collected from 24 vegetation plots, it is concluded that the stream water conveyance plays an important role in lifting groundwater level. The groundwater nearby the watercourse was raised from 5~8 m in depth before the stream water conveyance to 2.5~5 m after stream water conveyance. The physiological response of Phragmites communis, Tamarix spp. And Populus euphratica to the change of groundwater is sensitive and represents a grads change obviously. The growth of the plants in the lower reaches of Tarim River is stressed by drought to various degrees. Lengthways, the drought stress exposed to the plants increases with groundwater depth from the upper sections to the lower sections; and breadthwise, the drought stress exposed to the plants is increased with the increase of distance away from the river channel of stream intermittent water releases and of the groundwater depth. Combining the field investigation and the analysis of the plots, it is considered that the stress groundwater depths for the Phragmites communis, Tamarix spp. And Populus euphratica are 3.5 m, 5 m and 4.5 m respectively.

  5. Geostatistical analysis of groundwater level using Euclidean and non-Euclidean distance metrics and variable variogram fitting criteria

    Science.gov (United States)

    Theodoridou, Panagiota G.; Karatzas, George P.; Varouchakis, Emmanouil A.; Corzo Perez, Gerald A.

    2015-04-01

    Groundwater level is an important information in hydrological modelling. Geostatistical methods are often employed to map the free surface of an aquifer. In geostatistical analysis using Kriging techniques the selection of the optimal variogram model is very important for the optimal method performance. This work compares three different criteria, the least squares sum method, the Akaike Information Criterion and the Cressie's Indicator, to assess the theoretical variogram that fits to the experimental one and investigates the impact on the prediction results. Moreover, five different distance functions (Euclidean, Minkowski, Manhattan, Canberra, and Bray-Curtis) are applied to calculate the distance between observations that affects both the variogram calculation and the Kriging estimator. Cross validation analysis in terms of Ordinary Kriging is applied by using sequentially a different distance metric and the above three variogram fitting criteria. The spatial dependence of the observations in the tested dataset is studied by fitting classical variogram models and the Matérn model. The proposed comparison analysis performed for a data set of two hundred fifty hydraulic head measurements distributed over an alluvial aquifer that covers an area of 210 km2. The study area is located in the Prefecture of Drama, which belongs to the Water District of East Macedonia (Greece). This area was selected in terms of hydro-geological data availability and geological homogeneity. The analysis showed that a combination of the Akaike information Criterion for the variogram fitting assessment and the Brays-Curtis distance metric provided the most accurate cross-validation results. The Power-law variogram model provided the best fit to the experimental data. The aforementioned approach for the specific dataset in terms of the Ordinary Kriging method improves the prediction efficiency in comparison to the classical Euclidean distance metric. Therefore, maps of the spatial

  6. Screening-level risk assessment for styrene-acrylonitrile (SAN) trimer detected in soil and groundwater.

    Science.gov (United States)

    Kirman, C R; Gargas, M L; Collins, J J; Rowlands, J C

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluated to assess potential on-site and off-site exposures, using parameter values for exposures to soil (oral, inhalation of particulates, and dermal contact) and groundwater (oral, dermal contact) to reflect central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. Three reference dose (RfD) values were derived for SAN Trimer for short-term, subchronic, and chronic exposures, based upon its effects on the liver in exposed rats. Benchmark (BMD) methods were used to assess the relationship between exposure and response, and to characterize appropriate points of departure (POD) for each RfD. An uncertainty factor of 300 was applied to each POD to yield RfD values of 0.1, 0.04, and 0.03 mg/kg-d for short-term, subchronic, and chronic exposures, respectively. Because a chronic cancer bioassay for SAN Trimer in rats (NTP 2011a) does not provide evidence of carcinogenicity, a cancer risk assessment is not appropriate for this chemical. Potential health hazards to human health were assessed using a hazard index (HI) approach, which considers the ratio of exposure dose (i.e., average daily dose, mg/kg-d) to toxicity dose (RfD, mg/kg-d) for each scenario. All CTE and RME HI values are well below 1 (where the average daily dose is equivalent to the RfD), indicating that there is no concern for potential noncancer effects in exposed populations even under the conservative assumptions of this screening-level assessment.

  7. Characterization of sediment and measurement of groundwater levels and temperatures, Camas National Wildlife Refuge, eastern Idaho

    Science.gov (United States)

    Twining, Brian V.; Rattray, Gordon W.

    2016-11-02

    The Camas National Wildlife Refuge (Refuge) in eastern Idaho, established in 1937, contains wetlands, ponds, and wet meadows that are essential resting and feeding habitat for migratory birds and nesting habitat for waterfowl. Initially, natural sources of water supported these habitats. However, during the past few decades, climate change and changes in surrounding land use have altered and reduced natural groundwater and surface water inflows such that the wetlands, ponds, and wet meadows are now maintained through water management and groundwater pumping. These water management activities have proven to be inefficient and costly, prompting the Refuge to develop alternative water management options that are more efficient and less expensive. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, is studying the hydrogeology at the Refuge to provide information for developing alternative water management options.The hydrogeologic studies at the Refuge included characterizing the type, distribution, and hydraulic conductivity of surficial sediments and measuring water levels and temperatures in monitoring wells. Four monitoring wells and seven soil probe coreholes were drilled at the Refuge. Seven water level and temperature data loggers were installed in the wells and water levels and temperatures were continuously recorded from November 2014 to June 2016. Sediment cores were collected from the coreholes and sediment type and distribution were characterized from drillers’ notes, geophysical logs, corehole samples, and particle grain-size analysis. The hydraulic conductivities of sediments were estimated using the measured average grain size and the assumed textural maturity of the sediment, and ranged from about 20 to 290 feet per day.

  8. Records of wells, ground-water levels, and ground-water withdrawals in the lower Goose Creek Basin, Cassia County, Idaho

    Science.gov (United States)

    Mower, R.W.

    1954-01-01

    Investigations by the United States Geological Survey of Ground Water in the Southern border area of the Snake Rive Plain, south of the Snake River, a re concerned at the present time with delineation of the principal ground-water districts, the extent and location of existing ground-water developments, the possibilities for additional development, and the effects of ground-water development on the regimen of streams and reservoirs whose waters are appropriate for beneficial use. The lower part of the Goose Creek Basin is one of the important ground-water districts of the southern plains area and there are substantial but spotty developments of ground water for irrigation in the basin. Several thousand irrigable acres that are now dry could be put under irrigation if a dependable supply of ground water could be developed. The relations of the ground-water reservoirs to the regime of the Snake River and Goose Cree, and to the large body of ground water in the Snake River Plain north of the Snake, are poorly known. A large amount of geologic and hydrologic study remains to be done before those relations can be accurately determined. Investigations will be continued in the future but file work and preparation of a comprehensive report inevitably will be delayed. Therefore the available records are presented herein in order to make them accessible to farmers, well drillers, government agencies, and the general public. Interpretation of the records is not attempted in this report and is deferred pending the accumulation of additional and quantitative information. The data summarized herein include records of the locations and physical characteristics of wells, the depth to water in wells, fluctuations of water levels in observation wells, and estimated rates and volumes of seasonal ans yearly ground-water pumpage for irrigation, municipal, and other uses. This information is complete for work done as of December 31, 1952. The investigations upon which this report is

  9. Impact of coal gangue on the level of main trace elements in the shallow groundwater of a mine reclamation area

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Chen Longqian; Zhou Tianjian; Tang Qibao; Zhang Ting

    2011-01-01

    Coal gangue is the most used filling material during reclamation of areas suffering subsidence from mining.Main trace element levels (F,As,Hg,and Pb) in shallow groundwater in the reclamation area may be affected by leaching from the gangue.This can has an impact on the application of the water for agricultural irrigation or use as drinking water.Therefore,it is of great significance to understand the effect coal gangue has on the shallow groundwater of a reclaimed area.We studied the effect of coal gangue on fluorine,arsenic,mercury,and lead levels in the shallow groundwater of a reclamation area by testing the water and the coal gangue.One well near the reclamation area was used as a control well and element levels in water from this well and from the soil next to the well were also measured.The results show that the levels of these elements are increasing in the reclamation area over time.The increase in fluorine,arsenic,mercury,and lead in monitor wells varies from 7.42% to 8.26%,from 7.13% to 7.90%,from 4.85% to 6.48%,and from 4.69% to 6.42%,respectively.Fluorine and arsenic levels are lower in monitor wells than in the control water.The other elements are found in greater concentration than in the control.The Nemerow index also indicates that the shallow groundwater in the reclamation area Ⅰ is moderately affected by the back-filling coal gangue,while the shallow groundwater in the reclamation area Ⅱ and Ⅲ are slightly affected by the back-filling coal gangue.This shallow groundwater could be used for agricultural irrigation or for drinking.

  10. Groundwater-level and storage-volume changes in the Equus Beds aquifer near Wichita, Kansas, predevelopment through January 2015

    Science.gov (United States)

    Whisnant, Joshua A.; Hansen, Cristi V.; Eslick, Patrick J.

    2015-10-01

    Development of the Wichita well field began in the 1940s in the Equus Beds aquifer to provide the city of Wichita, Kansas, a new water-supply source. After development of the Wichita well field began, groundwater levels began to decline. Extensive development of irrigation wells that began in the 1970s also contributed to substantial groundwater-level declines. Groundwater-level declines likely enhance movement of brine from past oil and gas production near Burrton, Kansas, and natural saline water from the Arkansas River into the Wichita well field. Groundwater levels reached a historical minimum in 1993 because of drought conditions, irrigation, and the city of Wichita’s withdrawals from the aquifer. In 1993, the city of Wichita adopted the Integrated Local Water Supply Program to ensure that Wichita’s water needs would be met through the year 2050 and beyond as part of its efforts to manage the part of the Equus Beds aquifer Wichita uses. A key component of the Integrated Local Water Supply Program was the Equus Beds Aquifer Storage and Recovery project. The Aquifer Storage and Recovery project’s goal is to store and eventually recover groundwater and help protect the Equus Beds aquifer from oil-field brine water near Burrton, Kansas, and saline water from the Arkansas River. Since 1940, the U.S. Geological Survey has monitored groundwater levels and storage-volume changes in the Equus Beds aquifer to provide data to the city of Wichita in order to better manage its water supply.

  11. Quantifying uncertainty in predictions of groundwater levels using formal likelihood methods

    Science.gov (United States)

    Marchant, Ben; Mackay, Jonathan; Bloomfield, John

    2016-09-01

    Informal and formal likelihood methods can be used to quantify uncertainty in modelled predictions of groundwater levels (GWLs). Informal methods use a relatively subjective criterion to identify sets of plausible or behavioural parameters of the GWL models. In contrast, formal methods specify a statistical model for the residuals or errors of the GWL model. The formal uncertainty estimates are only reliable when the assumptions of the statistical model are appropriate. We apply the formal approach to historical reconstructions of GWL hydrographs from four UK boreholes. We test whether a model which assumes Gaussian and independent errors is sufficient to represent the residuals or whether a model which includes temporal autocorrelation and a general non-Gaussian distribution is required. Groundwater level hydrographs are often observed at irregular time intervals so we use geostatistical methods to quantify the temporal autocorrelation rather than more standard time series methods such as autoregressive models. According to the Akaike Information Criterion, the more general statistical model better represents the residuals of the GWL model. However, no substantial difference between the accuracy of the GWL predictions and the estimates of their uncertainty is observed when the two statistical models are compared. When the general model is applied, significant temporal correlation over periods ranging from 3 to 20 months is evident for the different boreholes. When the GWL model parameters are sampled using a Markov Chain Monte Carlo approach the distributions based on the general statistical model differ from those of the Gaussian model, particularly for the boreholes with the most autocorrelation. These results suggest that the independent Gaussian model of residuals is sufficient to estimate the uncertainty of a GWL prediction on a single date. However, if realistically autocorrelated simulations of GWL hydrographs for multiple dates are required or if the

  12. Flood Water Level Mapping and Prediction Due to Dam Failures

    Science.gov (United States)

    Musa, S.; Adnan, M. S.; Ahmad, N. A.; Ayob, S.

    2016-07-01

    Sembrong dam has undergone overflow failure. Flooding has been reported to hit the town, covering an area of up to Parit Raja, located in the district of Batu Pahat. This study aims to identify the areas that will be affected by flood in the event of a dam failure in Sembrong Dam, Kluang, Johor at a maximum level. To grasp the extent, the flood inundation maps have been generated by using the InfoWorks ICM and GIS software. By using these maps, information such as the depth and extent of floods can be identified the main ares flooded. The flood map was created starting with the collection of relevant data such as measuring the depth of the river and a maximum flow rate for Sembrong Dam. The data were obtained from the Drainage and Irrigation Department Malaysia and the Department of Survey and Mapping and HLA Associates Sdn. Bhd. Then, the data were analyzed according to the established Info Works ICM method. The results found that the flooded area were listed at Sri Lalang, Parit Sagil, Parit Sonto, Sri Paya, Parit Raja, Parit Sempadan, Talang Bunut, Asam Bubok, Tanjung Sembrong, Sungai Rambut and Parit Haji Talib. Flood depth obtained for the related area started from 0.5 m up to 1.2 m. As a conclusion, the flood emanating from this study include the area around the town of Ayer Hitam up to Parit Raja approximately of more than 20 km distance. This may give bad implication to residents around these areas. In future studies, other rivers such as Sungai Batu Pahat should be considered for this study to predict and reduce the yearly flood victims for this area.

  13. How geomorphology and groundwater level affect the spatio-temporal variability of riverine cold water patches?

    Science.gov (United States)

    Wawrzyniak, Vincent; Piégay, Hervé; Allemand, Pascal; Vaudor, Lise; Goma, Régis; Grandjean, Philippe

    2016-04-01

    Temperature is a key factor for river ecosystems. In summer, patches of cold water are formed in the river by groundwater seepage. These patches have strong ecological significance and extend to the surface water in a well-mixed riverine system. These patches can serve as thermal refuges for some fish species during summer. In this study, the temporal variability and spatial distribution of cold water patches were explored along a 50 km river reach (the lower Ain River, France) using thermal infrared airborne remote sensing. This study examines a new range of processes acting on cold water patches at different scales that have not previously been touched upon in the literature. Three airborne campaigns were conducted during the summers of 2010, 2011 and 2014. Based on these images, a large number of cold water patches were identified using an automated method. Four types of patches were observed: tributary plumes, cold side channels (former channels or point-bar backwater channels), side seeps (located directly in the river channel) and gravel bar seeps (occurring at the downstream end of gravel bars). Logistic regression was used to analyse the longitudinal distribution of cold water patches according to geomorphologic indicators reflecting current or past fluvial process. Side seeps were found to be related to the local geology. Cold side channels were correlated to contemporary and past lateral river mobility. Gravel bar seeps were related to the current development of bars and are more prevalent in wandering reaches than in single-bed incised and paved reaches. The logistic model was subsequently used to evaluate gravel bar seep variability in the past. The model suggests larger numbers of seeps in the mid-20th century when bar surface area was higher. Interannual variability in the occurrence and spatial extent of side seeps and gravel bar seeps appear to be related to groundwater level fluctuations. Cold side channels exhibited greater interannual stability

  14. Analysis of Water Level Fluctuations and TDS Variations in the Groundwater at Mewat (Nuh District, Haryana (India

    Directory of Open Access Journals (Sweden)

    Priyanka1

    2016-08-01

    Full Text Available Groundwater is the major source for fulfilling the water needs of domestic and agricultural sectors in Mewat district, Haryana, India and its continuous use has put an enormous pressure on the groundwater resource, which along with low rainfall and variable geographical conditions lead to the declining water levels. The other problem of this area is high salinity which is reported intruding to the freshwater zone1. Taking into account the twin problem of declining water level and high salinity the study was taken up jointly by National Institute of Hydrology, Roorkee; Sehgal Foundation, Gurgaon and Indian Institute of Technology, Roorkee. Groundwater level and TDS (Total dissolved solids data for pre-monsoon and post-monsoon seasons for the time period of 2011–2015 of 40 monitoring wells developed by Sehgal Foundation, Gurgaon was collected and analysed. It has been found that the groundwater level is decreasing in the area while TDS values show inconsistent trends during 2011-15. Further monitoring of the wells is continued to get the more information on water level and TDS which will help in facilitating the researchers in finding out the applicable solutions for the above problems in the Mewat, Haryana.

  15. Spatiotemporal groundwater level modeling using hybrid artificial intelligence-meshless method

    Science.gov (United States)

    Nourani, Vahid; Mousavi, Shahram

    2016-05-01

    Uncertainties of the field parameters, noise of the observed data and unknown boundary conditions are the main factors involved in the groundwater level (GL) time series which limit the modeling and simulation of GL. This paper presents a hybrid artificial intelligence-meshless model for spatiotemporal GL modeling. In this way firstly time series of GL observed in different piezometers were de-noised using threshold-based wavelet method and the impact of de-noised and noisy data was compared in temporal GL modeling by artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). In the second step, both ANN and ANFIS models were calibrated and verified using GL data of each piezometer, rainfall and runoff considering various input scenarios to predict the GL at one month ahead. In the final step, the simulated GLs in the second step of modeling were considered as interior conditions for the multiquadric radial basis function (RBF) based solve of governing partial differential equation of groundwater flow to estimate GL at any desired point within the plain where there is not any observation. In order to evaluate and compare the GL pattern at different time scales, the cross-wavelet coherence was also applied to GL time series of piezometers. The results showed that the threshold-based wavelet de-noising approach can enhance the performance of the modeling up to 13.4%. Also it was found that the accuracy of ANFIS-RBF model is more reliable than ANN-RBF model in both calibration and validation steps.

  16. A method to improve the stability and accuracy of ANN- and SVM-based time series models for long-term groundwater level predictions

    Science.gov (United States)

    Yoon, Heesung; Hyun, Yunjung; Ha, Kyoochul; Lee, Kang-Kun; Kim, Gyoo-Bum

    2016-05-01

    The prediction of long-term groundwater level fluctuations is necessary to effectively manage groundwater resources and to assess the effects of changes in rainfall patterns on groundwater resources. In the present study, a weighted error function approach was utilised to improve the performance of artificial neural network (ANN)- and support vector machine (SVM)-based recursive prediction models for the long-term prediction of groundwater levels in response to rainfall. The developed time series models were applied to groundwater level data from 5 groundwater-monitoring stations in South Korea. The results demonstrated that the weighted error function approach can improve the stability and accuracy of recursive prediction models, especially for ANN models. The comparison of the model performance showed that the recursive prediction performance of the SVM was superior to the performance of the ANN in this case study.

  17. Optimal level of groundwater charge to promote rainwater usage for irrigation in rural Beijing

    NARCIS (Netherlands)

    X. Liang (Xiao); M.P. van Dijk (Meine Pieter)

    2011-01-01

    textabstractAbstract: Since groundwater is diminishing rapidly in rural Beijing, rainwater harvesting for irrigation is being promoted. As the cost of pumping up groundwater is low, farmers have few incentives to use rainwater. To promote the consumption of rainwater, the Beijing Water Authority may

  18. Microbial Community-Level Physiological Profiles (CLPP) and herbicide mineralization potential in groundwater affected by agricultural land use

    Science.gov (United States)

    Janniche, Gry Sander; Spliid, Henrik; Albrechtsen, Hans-Jørgen

    2012-10-01

    Diffuse groundwater pollution from agricultural land use may impact the microbial groundwater community, which was investigated as Community-Level Physiological Profiles (CLPP) using EcoPlate™. Water was sampled from seven piezometers and a spring in a small agricultural catchment with diffuse herbicide and nitrate pollution. Based on the Shannon-Wiener and Simpson's diversity indices the diversity in the microbial communities was high. The response from the EcoPlates™ showed which substrates support groundwater bacteria, and all 31 carbon sources were utilized by organisms from at least one water sample. However, only nine carbon sources were utilized by all water samples: D-Mannitol, N-acetyl-D-glucosamine, putrescine, D-galacturonic acid, itaconic acid, 4-hydroxy benzoic acid, tween 40, tween 80, and L-asparagine. In all water samples the microorganisms preferred D-mannitol, D-galacturonic acid, tween 40, and 4-hydroxy benzoic acid as substrates, whereas none preferred 2-hydroxy benzoic acid, α-D-lactose, D,L-α-glycerol phosphate, α-ketobutyric acid, L-threonine and glycyl-L-glutamic acid. Principal Component Analysis of the CLPP's clustered the most agriculturally affected groundwater samples, indicating that the agricultural land use affects the groundwater microbial communities. Furthermore, the ability to mineralize atrazine and isoproturon, which have been used in the catchment, was also associated with this cluster.

  19. Global assessment of vulnerability to sea-level rise in topography-limited and recharge-limited coastal groundwater systems

    Science.gov (United States)

    Michael, Holly A.; Russoniello, Christopher J.; Byron, Lindsay A.

    2013-04-01

    Impacts of rising sea level on the hydraulic balance between aquifers and the ocean threaten fresh water resources and aquatic ecosystems along many world coastlines. Understanding the vulnerability of groundwater systems to these changes and the primary factors that determine the magnitude of system response is critical to developing effective management and adaptation plans in coastal zones. We assessed the vulnerability of two types of groundwater systems, recharge-limited and topography-limited, to changes caused by sea-level rise over a range of hydrogeologic settings. Vulnerability in this context is defined by the rate and magnitude of salinization of coastal aquifers and changes in groundwater flow to the sea. Two-dimensional variable-density groundwater flow and salt transport simulations indicate that the response of recharge-limited systems is largely minimal, whereas topography-limited systems are vulnerable for various combinations of permeability, vertical anisotropy in permeability, and recharge. World coastlines were classified according to system type as a vulnerability indicator. Results indicate that approximately 70% of world coastlines may be topography-limited, though variability in hydrogeologic conditions strongly affects classification. Future recharge and sea-level rise scenarios have much less influence on the proportion of vulnerable coastlines than differences in permeability, distance to a hydraulic divide, and recharge, indicating that hydrogeologic properties and setting are more important factors to consider in determining system type than uncertainties in the magnitude of sea-level rise and hydrologic shifts associated with future climate change.

  20. The backend design of an environmental monitoring system upon real-time prediction of groundwater level fluctuation under the hillslope.

    Science.gov (United States)

    Lin, Hsueh-Chun; Hong, Yao-Ming; Kan, Yao-Chiang

    2012-01-01

    The groundwater level represents a critical factor to evaluate hillside landslides. A monitoring system upon the real-time prediction platform with online analytical functions is important to forecast the groundwater level due to instantaneously monitored data when the heavy precipitation raises the groundwater level under the hillslope and causes instability. This study is to design the backend of an environmental monitoring system with efficient algorithms for machine learning and knowledge bank for the groundwater level fluctuation prediction. A Web-based platform upon the model-view controller-based architecture is established with technology of Web services and engineering data warehouse to support online analytical process and feedback risk assessment parameters for real-time prediction. The proposed system incorporates models of hydrological computation, machine learning, Web services, and online prediction to satisfy varieties of risk assessment requirements and approaches of hazard prevention. The rainfall data monitored from the potential landslide area at Lu-Shan, Nantou and Li-Shan, Taichung, in Taiwan, are applied to examine the system design.

  1. GIS-based groundwater potential mapping using boosted regression tree, classification and regression tree, and random forest machine learning models in Iran.

    Science.gov (United States)

    Naghibi, Seyed Amir; Pourghasemi, Hamid Reza; Dixon, Barnali

    2016-01-01

    Groundwater is considered one of the most valuable fresh water resources. The main objective of this study was to produce groundwater spring potential maps in the Koohrang Watershed, Chaharmahal-e-Bakhtiari Province, Iran, using three machine learning models: boosted regression tree (BRT), classification and regression tree (CART), and random forest (RF). Thirteen hydrological-geological-physiographical (HGP) factors that influence locations of springs were considered in this research. These factors include slope degree, slope aspect, altitude, topographic wetness index (TWI), slope length (LS), plan curvature, profile curvature, distance to rivers, distance to faults, lithology, land use, drainage density, and fault density. Subsequently, groundwater spring potential was modeled and mapped using CART, RF, and BRT algorithms. The predicted results from the three models were validated using the receiver operating characteristics curve (ROC). From 864 springs identified, 605 (≈70 %) locations were used for the spring potential mapping, while the remaining 259 (≈30 %) springs were used for the model validation. The area under the curve (AUC) for the BRT model was calculated as 0.8103 and for CART and RF the AUC were 0.7870 and 0.7119, respectively. Therefore, it was concluded that the BRT model produced the best prediction results while predicting locations of springs followed by CART and RF models, respectively. Geospatially integrated BRT, CART, and RF methods proved to be useful in generating the spring potential map (SPM) with reasonable accuracy.

  2. Development of a model to simulate groundwater inundation induced by sea-level rise and high tides in Honolulu, Hawaii.

    Science.gov (United States)

    Habel, Shellie; Fletcher, Charles H; Rotzoll, Kolja; El-Kadi, Aly I

    2017-05-01

    Many of the world's largest cities face risk of sea-level rise (SLR) induced flooding owing to their limited elevations and proximities to the coastline. Within this century, global mean sea level is expected to reach magnitudes that will exceed the ground elevation of some built infrastructure. The concurrent rise of coastal groundwater will produce additional sources of inundation resulting from narrowing and loss of the vertical unsaturated subsurface space. This has implications for the dense network of buried and low-lying infrastructure that exists across urban coastal zones. Here, we describe a modeling approach that simulates narrowing of the unsaturated space and groundwater inundation (GWI) generated by SLR-induced lifting of coastal groundwater. The methodology combines terrain modeling, groundwater monitoring, estimation of tidal influence, and numerical groundwater-flow modeling to simulate future flood scenarios considering user-specified tide stages and magnitudes of SLR. We illustrate the value of the methodology by applying it to the heavily urbanized and low-lying Waikiki area of Honolulu, Hawaii. Results indicate that SLR of nearly 1 m generates GWI across 23% of the 13 km(2) study area, threatening $5 billion of taxable real estate and 48 km of roadway. Analysis of current conditions reveals that 86% of 259 active cesspool sites in the study area are likely inundated. This suggests that cesspool effluent is currently entering coastal groundwater, which not only leads to degradation of coastal environments, but also presents a future threat to public health as GWI would introduce effluent at the ground surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Anomalous frequency characteristics of groundwater levels before major earthquakes in Taiwan

    Directory of Open Access Journals (Sweden)

    C.-H. Chen

    2012-06-01

    Full Text Available Unusual decreases in water levels were consistently observed in 78% (=42/54 of the wells in the Choshuichi Alluvial Fan of central Taiwan roughly 150 days before the Chi-Chi earthquake (M = 7.6 on 20 September 1999 when the influences of barometric pressure, earth tides, precipitation and artificial pumping were removed. Variations in groundwater levels measured in the anomalous wells between 1 August 1997 and 19 September 1999, the time period covering the unusual decreases, were transferred into the frequency domain to examine anomalous frequency bands associated with the Chi-Chi earthquake. Analytical results show that amplitudes at the frequency band between 0.02 day−1 and 0.04 day−1 were generally maintained at the low stage and were enhanced in the few weeks before the Chi-Chi earthquake. Variations in amplitude within this particular frequency band were further examined in association with earthquakes (M > 6 between 1 August 1997 and 31 December 2009. Enhanced amplitude phenomena are consistently observed prior to the other two earthquakes (the Rei-Li and Ming-Jian earthquakes during the 12.5 yr, which sheds a promising light on research into precursors of strong earthquakes when combined with other geophysical observations such as geomagnetic anomalies and crustal displacements.

  4. Using Hydrologic Data from Africa in a Senior-Level Course in Groundwater Hydrology (Invited)

    Science.gov (United States)

    Silliman, S. E.

    2010-12-01

    Ongoing research efforts in Benin, West Africa, and Uganda, East Africa, have provided substantial data sets involving groundwater quality, applied geophysics, water use, and response of local populations / government agencies to challenges related to water development, protection and management. Ranging from characterization of coastal salt-water encroachment to a major well field to nitrate and microbial contamination of rural water supplies, these data sets were developed by interdisciplinary / international teams that included both undergraduate and graduate students. The present discussion focuses on the integration of the resulting data sets into a senior-level (and lower-level graduate student) course in Groundwater Hydrology. The data sets are employed in multiple ways, including: (i) support of concepts introduced during lectures, (ii) problem sets involving analysis of the data, and (iii) foundation material for open-ended discussions on comparative water resource strategies in developed and developing countries. Most significant in terms of the use of these data sets to advance educational opportunities, the African case studies have been integrated into semester-long projects completed by teams of students as a significant component of their final grade as well as one of their engineering design experiences used to fulfill ABET requirements. During the 2009-2010 academic year, these data sets (as well as published data bases by other agencies) were used by individual groups to design water development strategies for rural villages. During the present semester, two teams of students are pursuing long-term sustainability analyses, the first focused on an aquifer system in northern Indiana (USA) and the second focused on a coastal aquifer system serving Cotonou, Benin. The goal of pursuing these parallel projects is to illustrate to the students the similarities and differences involved in water resource management / protection in different parts of the

  5. Manifold mapping: a two-level optimization technique

    NARCIS (Netherlands)

    Echeverria, D.; Hemker, P.W.

    2008-01-01

    In this paper, we analyze in some detail the manifold-mapping optimization technique introduced recently [Echeverría and Hemker in space mapping and defect correction. Comput Methods Appl Math 5(2): 107-–136, 2005]. Manifold mapping aims at accelerating optimal design procedures that otherwise requi

  6. Manifold mapping: a two-level optimization technique

    NARCIS (Netherlands)

    Echeverría, D.; Hemker, P.W.

    2008-01-01

    In this paper, we analyze in some detail the manifold-mapping optimization technique introduced recently [Echeverría and Hemker in space mapping and defect correction. Comput Methods Appl Math 5(2): 107--136, 2005]. Manifold mapping aims at accelerating optimal design procedures that otherwise requi

  7. Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

    Directory of Open Access Journals (Sweden)

    F. Jørgensen

    2012-03-01

    Full Text Available Geophysical techniques are increasingly used as tools for characterising the subsurface and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark a combination of an airborne transient electromagnetic survey (performed with the SkyTEM system, a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m giving a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, deep and shallow buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological elements mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area thus providing important information on the fresh-saltwater boundary and the chemical status of groundwater. Although, the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore is strongly influenced by the increased electrical conductivity here, buried valleys and other geological elements are still revealed. The salinity distribution indicates preferential flow paths through and along specific geological elements within the area. The effects of future sea level rise on the groundwater system and chemical status are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and assessing their control on the groundwater salinity distribution.

  8. Long-term (1930-2010) trends in groundwater levels in Texas: influences of soils, landcover and water use.

    Science.gov (United States)

    Chaudhuri, Sriroop; Ale, Srinivasulu

    2014-08-15

    Rapid groundwater depletion has raised grave concerns about sustainable development in many parts of Texas, as well as in other parts of the world. Previous hydrologic investigations on groundwater levels in Texas were conducted mostly on aquifer-specific basis, and hence lacked state-wide panoramic view. The aim of this study was to present a qualitative overview of long-term (1930-2010) trends in groundwater levels in Texas and identify spatial patterns by applying different statistical (boxplots, correlation-regression, hierarchical cluster analysis) and geospatial techniques (Moran's I, Local Indicators of Spatial Association) on 136,930 groundwater level observations from Texas Water Development Board's database. State-wide decadal median water-levels declined from about 14 m from land surface in the 1930s to about 36 m in the 2000s. Number of counties with deeper median water-levels (water-level depth>100 m) increased from 2 to 13 between 1930s and 2000s, accompanied by a decrease in number of counties having shallower median water-levels (water-level depthlandcover, geology and soil properties distinguished Texas Panhandle from GMA 8. Irrigated agriculture is the major cause of depletion in the Texas Panhandle as compared to increasing urbanization in GMA 8. Overall our study indicated that use of robust spatial and statistical methods can reveal important details about the trends in water-level changes and shed lights on the associated factors. Due to very generic nature, techniques used in this study can also be applied to other areas with similar eco-hydrologic issues to identify regions that warrant future management actions.

  9. Groundwater resource vulnerability and spatial variability of nitrate contamination: Insights from high density tubewell monitoring in a hard rock aquifer.

    Science.gov (United States)

    Buvaneshwari, Sriramulu; Riotte, Jean; Sekhar, M; Mohan Kumar, M S; Sharma, Amit Kumar; Duprey, Jean Louis; Audry, Stephane; Giriraja, P R; Praveenkumarreddy, Yerabham; Moger, Hemanth; Durand, Patrick; Braun, Jean-Jacques; Ruiz, Laurent

    2017-02-01

    Agriculture has been increasingly relying on groundwater irrigation for the last decades, leading to severe groundwater depletion and/or nitrate contamination. Understanding the links between nitrate concentration and groundwater resource is a prerequisite for assessing the sustainability of irrigated systems. The Berambadi catchment (ORE-BVET/Kabini Critical Zone Observatory) in Southern India is a typical example of intensive irrigated agriculture and then an ideal site to study the relative influences of land use, management practices and aquifer properties on NO3 spatial distribution in groundwater. The monitoring of >200 tube wells revealed nitrate concentrations from 1 to 360mg/L. Three configurations of groundwater level and elevation gradient were identified: i) NO3 hot spots associated to deep groundwater levels (30-60m) and low groundwater elevation gradient suggest small groundwater reserve with absence of lateral flow, then degradation of groundwater quality due to recycling through pumping and return flow; ii) high groundwater elevation gradient, moderate NO3 concentrations suggest that significant lateral flow prevented NO3 enrichment; iii) low NO3 concentrations, low groundwater elevation gradient and shallow groundwater indicate a large reserve. We propose that mapping groundwater level and gradient could be used to delineate zones vulnerable to agriculture intensification in catchments where groundwater from low-yielding aquifers is the only source of irrigation. Then, wells located in low groundwater elevation gradient zones are likely to be suitable for assessing the impacts of local agricultural systems, while wells located in zones with high elevation gradient would reflect the average groundwater quality of the catchment, and hence should be used for regional mapping of groundwater quality. Irrigation with NO3 concentrated groundwater induces a "hidden" input of nitrogen to the crop which can reach 200kgN/ha/yr in hotspot areas, enhancing

  10. Modelling the response of shallow groundwater levels to combined climate and water-diversion scenarios in Beijing-Tianjin-Hebei Plain, China

    Science.gov (United States)

    Li, Xue; Ye, Si-Yuan; Wei, Ai-Hua; Zhou, Peng-Peng; Wang, Li-Heng

    2017-09-01

    A three-dimensional groundwater flow model was implemented to quantify the temporal variation of shallow groundwater levels in response to combined climate and water-diversion scenarios over the next 40 years (2011-2050) in Beijing-Tianjin-Hebei (Jing-Jin-Ji) Plain, China. Groundwater plays a key role in the water supply, but the Jing-Jin-Ji Plain is facing a water crisis. Groundwater levels have declined continuously over the last five decades (1961-2010) due to extensive pumping and climate change, which has resulted in decreased recharge. The implementation of the South-to-North Water Diversion Project (SNWDP) will provide an opportunity to restore the groundwater resources. The response of groundwater levels to combined climate and water-diversion scenarios has been quantified using a groundwater flow model. The impacts of climate change were based on the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset for future high (A2), medium (A1B), and low (B1) greenhouse gas scenarios; precipitation data from CMIP3 were applied in the model. The results show that climate change will slow the rate of decrease of the shallow groundwater levels under three climate-change scenarios over the next 40 years compared to the baseline scenario; however, the shallow groundwater levels will rise significantly (maximum of 6.71 m) when considering scenarios that combine climate change and restrictions on groundwater exploitation. Restrictions on groundwater exploitation for water resource management are imperative to control the decline of levels in the Jing-Jin-Ji area.

  11. Modelling the response of shallow groundwater levels to combined climate and water-diversion scenarios in Beijing-Tianjin-Hebei Plain, China

    Science.gov (United States)

    Li, Xue; Ye, Si-Yuan; Wei, Ai-Hua; Zhou, Peng-Peng; Wang, Li-Heng

    2017-03-01

    A three-dimensional groundwater flow model was implemented to quantify the temporal variation of shallow groundwater levels in response to combined climate and water-diversion scenarios over the next 40 years (2011-2050) in Beijing-Tianjin-Hebei (Jing-Jin-Ji) Plain, China. Groundwater plays a key role in the water supply, but the Jing-Jin-Ji Plain is facing a water crisis. Groundwater levels have declined continuously over the last five decades (1961-2010) due to extensive pumping and climate change, which has resulted in decreased recharge. The implementation of the South-to-North Water Diversion Project (SNWDP) will provide an opportunity to restore the groundwater resources. The response of groundwater levels to combined climate and water-diversion scenarios has been quantified using a groundwater flow model. The impacts of climate change were based on the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset for future high (A2), medium (A1B), and low (B1) greenhouse gas scenarios; precipitation data from CMIP3 were applied in the model. The results show that climate change will slow the rate of decrease of the shallow groundwater levels under three climate-change scenarios over the next 40 years compared to the baseline scenario; however, the shallow groundwater levels will rise significantly (maximum of 6.71 m) when considering scenarios that combine climate change and restrictions on groundwater exploitation. Restrictions on groundwater exploitation for water resource management are imperative to control the decline of levels in the Jing-Jin-Ji area.

  12. Interim Status Groundwater Monitoring Plan for Low-Level Waste Management Areas 1 to 4, RCRA Facilities, Hanford,Washington

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P Evan

    2004-10-25

    This document describes the monitoring plan to meet the requirements for interim status groundwater monitoring at Hanford Site low-level waste burial grounds as specified by 40 CFR 265, incorporated by reference in WAC 173-303-400. The monitoring will take place at four separate low-level waste management areas in the 200-West and 200-East Areas, in the central part of the site. This plan replaces the previous monitoring plan.

  13. Vulnerability mapping of groundwater contamination based on 3D lithostratigraphical models of porous aquifers.

    Science.gov (United States)

    Ducci, Daniela; Sellerino, Mariangela

    2013-03-01

    The aim of this paper is to apply a methodology in order to reconstruct a lithostratigraphic 3D model of an aquifer so as to define some parameters involved in the evaluation of the aquifer vulnerability to contamination of porous aquifers. The DRASTIC, SINTACS and AVI methods have been applied to an alluvial coastal aquifer of southern Italy. The stratigraphic reconstruction has been obtained by interpolating stratigraphic data from more than one borehole per 2 km. The lithostratigraphic reconstruction of a 3D model has been applied and used for three-dimensional or two-dimensional representations. In the first two methods, the layers of the vadose zone and the aquifer media have been evaluated not only by the interpolation of the single boreholes and piezometers, but also by the 3D model, assigning the scores of the parameters of each layer of the 3D model. The comparison between the maps constructed from the weighted values in each borehole and the maps deriving from the attribution of the values of each layer of the 3D model, highlights that the second representation avoids or minimizes the "bullseye" effect linked to the presence of boreholes with higher or lower values. The study has demonstrated that it is possible to integrate a 3D lithostratigraphic model of an aquifer in the assessment of the parameters involved in the evaluation of the aquifer vulnerability to contamination by Point Count System methods.

  14. Plant traits in response to raising groundwater levels in wetland restoration: evidence from three case studies

    NARCIS (Netherlands)

    Bodegom, van P.M.; Grootjans, A.P.; Sorrell, B.K.; Bekker, R.M.; Bakker, C.; Ozinga, W.A.

    2006-01-01

    Question: Is raising groundwater tables successful as a wetland restoration strategy? Location: Kennemer dunes, The Netherlands; Moksloot dunes, The Netherlands and Bullock Creek fen, New Zealand. Methods: Generalizations were made by analysing soil dynamics and the responsiveness of integrative pla

  15. Plant traits in response to raising groundwater levels in wetland restoration : evidence from three case studies

    NARCIS (Netherlands)

    Bodegom, P.M. van; Grootjans, A.P.; Sorrell, B.K.; Bekker, R.M.; Bakker, C.; Ozinga, W.A.; Middleton, B.

    2006-01-01

    Question: Is raising groundwater tables successful as a wetland restoration strategy? Location: Kennemer dunes, The Netherlands; Moksloot dunes, The Netherlands and Bullock Creek fen, New Zealand. Methods: Generalizations were made by analysing soil dynamics and the responsiveness of integrative pla

  16. Influence of irrigation on the level, salinity and flow of groundwater at ...

    African Journals Online (AJOL)

    2010-03-31

    Mar 31, 2010 ... Suitable internal subsurface drainage should be cleaned, ... Keywords: Drainage, irrigation and scheduling, soil water quality, water and salt balance ..... groundwater was pumped or bailed out of the piezometers and.

  17. Environmental impact of radionuclide migration in groundwater from a low-intermediate level radioactive waste repository

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The radionuclide migration from a certain Chinese repository withlow-intermediate level radioactive solid waste is studied. The migration in groundwater is analyzed and computed in detail. Under presumption of normal releasing, or the bottom of the repository has been marinated for one month with precipitation reaching 600 mm once and a 6m aerated zone exists, a prediction for 7 radionuclides is conducted. It shows that the aerated zone is the primary barrier for migration. The migration for radionuclides 60Co, 137Cs, 90Sr, 63Ni, etc. will be retarded in it within 500 years. The concentration of 239Pu will be decreased by amount of 6 order. Only 3H and 14C can migrate through the aerated zone. The radionuclides that go through the aerated zone and enter the aquifer will exist in spring, stream and sea. Based on this, the intake dose by residents in different age group resulting from drinking contaminated spring water, eating seafood is calculated. The results showed that the impact of the repository to the key resident group is lower than the limit in national repository regulation standard. This complies with the repository management target.

  18. Simulation and assessment of groundwater flow and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2003 through 2013: Chapter B of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    Science.gov (United States)

    Jones, Perry M.; Roth, Jason L.; Trost, Jared J.; Christenson, Catherine A.; Diekoff, Aliesha L.; Erickson, Melinda L.

    2017-09-05

    Water levels during 2003 through 2013 were less than mean water levels for the period 1925–2013 for several lakes in the northeast Twin Cities Metropolitan Area in Minnesota. Previous periods of low lake-water levels generally were correlated with periods with less than mean precipitation. Increases in groundwater withdrawals and land-use changes have brought into question whether or not recent (2003–13) lake-water-level declines are solely caused by decreases in precipitation. A thorough understanding of groundwater and surface-water exchanges was needed to assess the effect of water-management decisions on lake-water levels. To address this need, the U.S. Geological Survey, in cooperation with the Metropolitan Council and the Minnesota Department of Health, developed and calibrated a three-dimensional, steady-state groundwater-flow model representing 2003–13 mean hydrologic conditions to assess groundwater and lake-water exchanges, and the effects of groundwater withdrawals and precipitation on water levels of 96 lakes in the northeast Twin Cities Metropolitan Area.Lake-water budgets for the calibrated groundwater-flow model indicated that groundwater is flowing into lakes in the northeast Twin Cities Metropolitan Area and lakes are providing water to underlying aquifers. Lake-water outflow to the simulated groundwater system was a major outflow component for Big Marine Lake, Lake Elmo, Snail Lake, and White Bear Lake, accounting for 45 to 64 percent of the total outflows from the lakes. Evaporation and transpiration from the lake surface ranged from 19 to 52 percent of the total outflow from the four lakes. Groundwater withdrawals and precipitation were varied from the 2003‒13 mean values used in the calibrated model (30-percent changes in groundwater withdrawals and 5-percent changes in precipitation) for hypothetical scenarios to assess the effects of groundwater withdrawals and precipitation on water budgets and levels in Big Marine Lake, Snail Lake

  19. Groundwater level and specific conductance monitoring at Marine Corps Base, Camp Lejeune, Onslow County, North Carolina, 2007-2008

    Science.gov (United States)

    McSwain, Kristen Bukowski

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Marine Corps Base, Camp Lejeune, monitored water-resources conditions in the surficial, Castle Hayne, Peedee, and Black Creek aquifers in Onslow County, North Carolina, from November 2007 through September 2008. To comply with North Carolina Central Coastal Plain Capacity Use Area regulations, large-volume water suppliers in Onslow County must reduce their dependency on the Black Creek aquifer as a water-supply source and have, instead, proposed using the Castle Hayne aquifer as an alternative water-supply source. The Marine Corps Base, Camp Lejeune, uses water obtained from the unregulated surficial and Castle Hayne aquifers for drinking-water supply. Water-level data were collected and field measurements of physical properties were made at 19 wells at 8 locations spanning the Marine Corps Base, Camp Lejeune. These wells were instrumented with near real-time monitoring equipment to collect hourly measurements of water level. Additionally, specific conductance and water temperature were measured hourly in 16 of the 19 wells. Graphs are presented relating altitude of groundwater level to water temperature and specific conductance measurements collected during the study, and the relative vertical gradients between aquifers are discussed. The period-of-record normal (25th to 75th percentile) monthly mean groundwater levels at two well clusters were compared to median monthly mean groundwater levels at these same well clusters for 2008 to determine groundwater-resources conditions. In 2008, water levels were below normal in the 3 wells at one of the well clusters and were normal in 4 wells at the other cluster.

  20. Transfer of European Approach to Groundwater Monitoring in China

    Science.gov (United States)

    Zhou, Y.

    2007-12-01

    Major groundwater development in North China has been a key factor in the huge economic growth and the achievement of self sufficiency in food production. Groundwater accounts for more than 70 percent of urban water supply and provides important source of irrigation water during dry period. This has however caused continuous groundwater level decline and many associated problems: hundreds of thousands of dry wells, dry river beds, land subsidence, seawater intrusion and groundwater quality deterioration. Groundwater levels in the shallow unconfined aquifers have fallen 10m up to 50m, at an average rate of 1m/year. In the deep confined aquifers groundwater levels have commonly fallen 30m up to 90m, at an average rate of 3 to 5m/year. Furthermore, elevated nitrate concentrations have been found in shallow groundwater in large scale. Pesticides have been detected in vulnerable aquifers. Urgent actions are necessary for aquifer recovery and mitigating groundwater pollution. Groundwater quantity and quality monitoring plays a very important role in formulating cost-effective groundwater protection strategies. In 2000 European Union initiated a Water Framework Directive (2000/60/EC) to protect all waters in Europe. The objective is to achieve good water and ecological status by 2015 cross all member states. The Directive requires monitoring surface and groundwater in all river basins. A guidance document for monitoring was developed and published in 2003. Groundwater monitoring programs are distinguished into groundwater level monitoring and groundwater quality monitoring. Groundwater quality monitoring is further divided into surveillance monitoring and operational monitoring. The monitoring guidance specifies key principles for the design and operation of monitoring networks. A Sino-Dutch cooperation project was developed to transfer European approach to groundwater monitoring in China. The project aims at building a China Groundwater Information Centre. Case studies

  1. Assessment of fluoride level in groundwater and prevalence of dental fluorosis in Didwana block of Nagaur district, Central Rajasthan, India.

    Science.gov (United States)

    Arif, M; Husain, I; Hussain, J; Kumar, S

    2013-10-01

    In India, for the high concentration of fluoride in groundwater, people are at risk of dental fluorosis. The problem is common in various states of India. The condition in Rajasthan is worse where all districts have such a problem. To study the fluoride concentration in groundwater and prevalence of dental fluorosis in Didwana block of Nagaur district, Central Rajasthan, India. The fluoride concentration in water of 54 villages was measured electrochemically, using fluoride ion selective electrode. Dental fluorosis was assessed in 1136 people residing in study area by Dean's classification for dental fluorosis. The fluoride concentration in groundwater in studied sites ranged from 0.5 to 8.5 mg/L. The concentration of fluoride was more than the maximum permissible limit set by WHO and Bureau of Indian Standards (1 mg/L) in 48 groundwater sources. Of 1136 people studied, 788 (69.4%; 95% CI: 66.7%-72.1%) had dental fluoros---252 had mild and 74 had severe dental fluorosis. High level of fluoride in drinking water of Didwana block of Nagaur district, Central Rajasthan, India, causes dental fluorosis in most people in the region and is an important health problem that needs prompt attention.

  2. Assessment of Fluoride Level in Groundwater and Prevalence of Dental Fluorosis in Didwana Block of Nagaur District, Central Rajasthan, India

    Directory of Open Access Journals (Sweden)

    S Kumar

    2013-10-01

    Full Text Available Background: In India, for the high concentration of fluoride in groundwater, people are at risk of dental fluorosis. The problem is common in various states of India. The condition in Rajasthan is worse where all districts have such a problem.Objective: To study the fluoride concentration in groundwater and prevalence of dental fluorosis in Didwana block of Nagaur district, Central Rajasthan, India.Methods: The fluoride concentration in water of 54 villages was measured electrochemically, using fluoride ion selective electrode. Dental fluorosis was assessed in 1136 people residing in study area by Dean's classification for dental fluorosis.Results: The fluoride concentration in groundwater in studied sites ranged from 0.5 to 8.5 mg/L. The concentration of fluoride was more than the maximum permissible limit set by WHO and Bureau of Indian Standards (1 mg/L in 48 groundwater sources. Of 1136 people studied, 788 (69.4%; 95% CI: 66.7%–72.1% had dental fluorosis—252 had mild and 74 had severe dental fluorosis.Conclusion: High level of fluoride in drinking water of Didwana block of Nagaur district, Central Rajasthan, India, causes dental fluorosis in most people in the region and is an important health problem that needs prompt attention.

  3. Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    Science.gov (United States)

    Jones, Perry M.; Trost, Jared J.; Erickson, Melinda L.

    2016-10-19

    OverviewThis study assessed lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes applying three approaches: statistical analysis, field study, and groundwater-flow modeling.  Statistical analyses of lake levels were completed to assess the effect of physical setting and climate on lake-level fluctuations of selected lakes. A field study of groundwater and surface-water interactions in selected lakes was completed to (1) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (2) estimate general ages for waters extracted from the wells, and (3) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake.  Groundwater flow was simulated using a steady-state, groundwater-flow model to assess regional groundwater and surface-water exchanges and the effects of groundwater withdrawals, climate, and other factors on water levels of northeast Twin Cities Metropolitan Area lakes.

  4. Geostatistical interpolation model selection based on ArcGIS and spatio-temporal variability analysis of groundwater level in piedmont plains, northwest China.

    Science.gov (United States)

    Xiao, Yong; Gu, Xiaomin; Yin, Shiyang; Shao, Jingli; Cui, Yali; Zhang, Qiulan; Niu, Yong

    2016-01-01

    Based on the geo-statistical theory and ArcGIS geo-statistical module, datas of 30 groundwater level observation wells were used to estimate the decline of groundwater level in Beijing piedmont. Seven different interpolation methods (inverse distance weighted interpolation, global polynomial interpolation, local polynomial interpolation, tension spline interpolation, ordinary Kriging interpolation, simple Kriging interpolation and universal Kriging interpolation) were used for interpolating groundwater level between 2001 and 2013. Cross-validation, absolute error and coefficient of determination (R(2)) was applied to evaluate the accuracy of different methods. The result shows that simple Kriging method gave the best fit. The analysis of spatial and temporal variability suggest that the nugget effects from 2001 to 2013 were increasing, which means the spatial correlation weakened gradually under the influence of human activities. The spatial variability in the middle areas of the alluvial-proluvial fan is relatively higher than area in top and bottom. Since the changes of the land use, groundwater level also has a temporal variation, the average decline rate of groundwater level between 2007 and 2013 increases compared with 2001-2006. Urban development and population growth cause over-exploitation of residential and industrial areas. The decline rate of the groundwater level in residential, industrial and river areas is relatively high, while the decreasing of farmland area and development of water-saving irrigation reduce the quantity of water using by agriculture and decline rate of groundwater level in agricultural area is not significant.

  5. Time prediction of an onset of shallow landslides based on the monitoring of the groundwater level and the surface displacement at different locations on a sandy model slope

    Science.gov (United States)

    Sasahara, Katsuo

    2016-04-01

    Location of monitoring of the deformation and the groundwater level in a slope is important for time-prediction of an onset of shallow landslides based on the monitoring. The analysis of the monitored data of the surface displacement and the groundwater level at different locations in sandy model slope under artificial rainfall was conducted in this study. The monitored data showed that the surface displacement increased with the increase of the groundwater level significantly. Then the analysis of the monitored data revealed that the relation between the surface displacement and the groundwater level can be modified as hyperbolic curve. The surface displacement grew larger and maximum groundwater level was smaller at farther location from the toe of the slope. Time-prediction of an onset of a landslide based on the monitored data at different location on the slope was proposed as following procedures. (1) To make a regression equation for the relation between the surface displacement and the groundwater level based on the monitored data at any time before the failure, (2) To make a regression equation for the relation between the time and the groundwater level based on the same data with (1), and (3) To incorporate the equation for the relation between the time and the groundwater level into that between the surface displacement and the groundwater level to derive the time - the surface displacement relation. (4) To derive the time - the inverse of the surface displacement velocity from the equation for the time - the surface displacement relation. The equation for the time - the surface displacement and the equation for the time - the inverse of the surface displacement velocity could simulate the actual phenomena of the slope well based on the monitored data at any location on the model slope.

  6. 高精度地下水位监测仪%High Precision Groundwater Level Monitor

    Institute of Scientific and Technical Information of China (English)

    钟佳迅; 庹先国; 王洪辉; 张兆义; 张贵宇

    2012-01-01

    Through studying the change of groundwater on the influence of the geological hazards, such as landslide, a high precision groundwater level monitor was designed. The monitor took advantage of static-pressure water level sensor to get ground-water level information. By means of sophisticated I/V conversion, high precision A/D conversion, high stability reference voltage and cooperating with curve fitting method, it realized the high precision collection of groundwater level information, and the system error was less than 1 mm. In the actual application, the instrument highlighted its advantages such as high precision, stable performance, small volume,installation flexible,convenient operation,etc. The monitor can be applied to all kinds of monitoring wells very well,and used in geological disaster monitoring.%通过地下水位变化对滑坡等地质灾害的影响研究,设计了一种高精度地下水位监测仪器.仪器采用静压力式水位传感器获取地下水位信息,通过精密I/V转换、高精度A/D转换及高稳定性基准电压,并配合曲线拟合方法,实现了地下水位信息的高精度采集,误差≤1 mm.在实际应用中,仪器突出了精度高、性能稳定、体积小、安装灵活、操作方便等优点,对各类监测井具有很强的适应性,适合用于地质灾害监测.

  7. Assessment of the impact of sea-level rise due to climate change on coastal groundwater discharge.

    Science.gov (United States)

    Masciopinto, Costantino; Liso, Isabella Serena

    2016-11-01

    An assessment of sea intrusion into coastal aquifers as a consequence of local sea-level rise (LSLR) due to climate change was carried out at Murgia and Salento in southern Italy. The interpolation of sea-level measurements at three tide-gauge stations was performed during the period of 2000 to 2014. The best fit of measurements shows an increasing rate of LSLR ranging from 4.4mm/y to 8.8mm/y, which will result in a maximum LSLR of approximately 2m during the 22nd century. The local rate of sea-level rise matches recent 21st and 22nd century projections of mean global sea-level rise determined by other researchers, which include increased melting rates of the Greenland and Antarctic ice sheets, the effect of ocean thermal expansion, the melting of glaciers and ice caps, and changes in the quantity of stored land water. Subsequently, Ghyben-Herzberg's equation for the freshwater/saltwater interface was rewritten in order to determine the decrease in groundwater discharge due to the maximum LSLR. Groundwater flow simulations and ArcGIS elaborations of digital elevation models of the coast provided input data for the Ghyben-Herzberg calculation under the assumption of head-controlled systems. The progression of seawater intrusion due to LSLR suggests an impressive depletion of available groundwater discharge during the 22nd century, perhaps as much as 16.1% of current groundwater pumping for potable water in Salento. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy

    Science.gov (United States)

    Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.

    2015-04-01

    The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping

  9. Investigating the effect of landfill leachates on the characteristics of dissolved organic matter in groundwater using excitation-emission matrix fluorescence spectra coupled with fluorescence regional integration and self-organizing map.

    Science.gov (United States)

    He, Xiao-Song; Fan, Qin-Dong

    2016-11-01

    For the purpose of investigating the effect of landfill leachate on the characteristics of organic matter in groundwater, groundwater samples were collected near and in a landfill site, and dissolved organic matter (DOM) was extracted from the groundwater samples and characterized by excitation-emission matrix (EEM) fluorescence spectra combined with fluorescence regional integration (FRI) and self-organizing map (SOM). The results showed that the groundwater DOM comprised humic-, fulvic-, and protein-like substances. The concentration of humic-like matter showed no obvious variation for all groundwater except the sample collected in the landfill site. Fulvic-like substance content decreased when the groundwater was polluted by landfill leachates. There were two kinds of protein-like matter in the groundwater. One kind was bound to humic-like substances, and its content did not change along with groundwater pollution. However, the other kind was present as "free" molecules or else bound in proteins, and its concentration increased significantly when the groundwater was polluted by landfill leachates. The FRI and SOM methods both can characterize the composition and evolution of DOM in the groundwater. However, the SOM analysis can identify whether protein-like moieties was bound to humic-like matter.

  10. First level seismic microzonation map of Chennai city – a GIS approach

    Directory of Open Access Journals (Sweden)

    G. P. Ganapathy

    2011-02-01

    Full Text Available Chennai city is the fourth largest metropolis in India, is the focus of economic, social and cultural development and it is the capital of the State of Tamil Nadu. The city has a multi-dimensional growth in development of its infrastructures and population. The area of Chennai has experienced moderate earthquakes in the historical past. Also the Bureau of Indian Standard upgraded the seismic status of Chennai from Low Seismic Hazard (Zone II to Moderate Seismic Hazard (Zone III–(BIS: 1893 (2001. In this connection, a first level seismic microzonation map of Chennai city has been produced with a GIS platform using the themes, viz, Peak Ground Acceleration (PGA, Shear wave velocity at 3 m, Geology, Ground water fluctuation and bed rock depth. The near potential seismic sources were identified from the remote-sensing study and seismo-tectonic details from published literatures. The peak ground acceleration for these seismic sources were estimated based on the attenuation relationship and the maximum PGA for Chennai is 0.176 g. The groundwater fluctuation of the city varies from 0–4 m below ground level. The depth to bedrock configuration shows trough and ridges in the bedrock topography all over the city. The seismic microzonation analysis involved grid datasets (the discrete datasets from different themes were converted to grids to compute the final seismic hazard grid through integration and weightage analysis of the source themes. The Chennai city has been classified into three broad zones, viz, High, Moderate and Low Seismic Hazard. The High seismic Hazard concentrated in a few places in the western central part of the city. The moderate hazard areas are oriented in NW-SE direction in the Western part. The southern and eastern part will have low seismic hazard. The result of the study may be used as first-hand information in selecting the appropriate earthquake resistant features in designing the forthcoming new buildings against seismic

  11. First level seismic microzonation map of Chennai city - a GIS approach

    Science.gov (United States)

    Ganapathy, G. P.

    2011-02-01

    Chennai city is the fourth largest metropolis in India, is the focus of economic, social and cultural development and it is the capital of the State of Tamil Nadu. The city has a multi-dimensional growth in development of its infrastructures and population. The area of Chennai has experienced moderate earthquakes in the historical past. Also the Bureau of Indian Standard upgraded the seismic status of Chennai from Low Seismic Hazard (Zone II) to Moderate Seismic Hazard (Zone III)-(BIS: 1893 (2001)). In this connection, a first level seismic microzonation map of Chennai city has been produced with a GIS platform using the themes, viz, Peak Ground Acceleration (PGA), Shear wave velocity at 3 m, Geology, Ground water fluctuation and bed rock depth. The near potential seismic sources were identified from the remote-sensing study and seismo-tectonic details from published literatures. The peak ground acceleration for these seismic sources were estimated based on the attenuation relationship and the maximum PGA for Chennai is 0.176 g. The groundwater fluctuation of the city varies from 0-4 m below ground level. The depth to bedrock configuration shows trough and ridges in the bedrock topography all over the city. The seismic microzonation analysis involved grid datasets (the discrete datasets from different themes were converted to grids) to compute the final seismic hazard grid through integration and weightage analysis of the source themes. The Chennai city has been classified into three broad zones, viz, High, Moderate and Low Seismic Hazard. The High seismic Hazard concentrated in a few places in the western central part of the city. The moderate hazard areas are oriented in NW-SE direction in the Western part. The southern and eastern part will have low seismic hazard. The result of the study may be used as first-hand information in selecting the appropriate earthquake resistant features in designing the forthcoming new buildings against seismic ground motion of the

  12. Design of a Multi-layer Lane-Level Map for Vehicle Route Planning

    Directory of Open Access Journals (Sweden)

    Liu Chaoran

    2017-01-01

    Full Text Available With the development of intelligent transportation system, there occurs further demand for high precision localization and route planning, and simultaneously the traditional road-level map fails to meet with this requirement, by which this paper is motivated. In this paper, t he three-layer lane-level map architecture for vehicle path guidance is established, and the mathematical models of road-level layer, intermediate layer and lane-level layer are designed considering efficiency and precision. The geometric model of the lane-level layer of the map is characterized by Cubic Hermite Spline for continuity. A method of generating the lane geometry with fixed and variable control points is proposed, which can effectively ensure the accuracy with limited num ber of control points. In experimental part, a multi-layer map of an intersection is built to validate the map model, and an example of a local map was generated with the lane-level geometry.

  13. Estimating seepage flux from ephemeral stream channels using surface water and groundwater level data

    Science.gov (United States)

    Noorduijn, Saskia L.; Shanafield, Margaret; Trigg, Mark A.; Harrington, Glenn A.; Cook, Peter G.; Peeters, L.

    2014-02-01

    Seepage flux from ephemeral streams can be an important component of the water balance in arid and semiarid regions. An emerging technique for quantifying this flux involves the measurement and simulation of a flood wave as it moves along an initially dry channel. This study investigates the usefulness of including surface water and groundwater data to improve model calibration when using this technique. We trialed this approach using a controlled flow event along a 1387 m reach of artificial stream channel. Observations were then simulated using a numerical model that combines the diffusion-wave approximation of the Saint-Vénant equations for streamflow routing, with Philip's infiltration equation and the groundwater flow equation. Model estimates of seepage flux for the upstream segments of the study reach, where streambed hydraulic conductivities were approximately 101 m d-1, were on the order of 10-4 m3 d-1 m-2. In the downstream segments, streambed hydraulic conductivities were generally much lower but highly variable (˜10-3 to 10-7 m d-1). A Latin Hypercube Monte Carlo sensitivity analysis showed that the flood front timing, surface water stage, groundwater heads, and the predicted streamflow seepage were most influenced by specific yield. Furthermore, inclusion of groundwater data resulted in a higher estimate of total seepage estimates than if the flood front timing were used alone.

  14. HTML::GMap-A High Level Perl Wrapper Around the Google Maps(TM) API

    Science.gov (United States)

    We have developed HTML::GMap, a generic, high-level Perl wrapper, to easily build web-based geographic map displays on top of the Google MapsTM Mapping Service. Using HTML::GMap, we built custom display tools to present the molecular diversity data generated by the National Science Foundation-suppor...

  15. Ground-water levels and water-quality data for wells in the Spring Creek area near Arnold Air Force Base, Tennessee, April and May 2000

    Science.gov (United States)

    Williams, Shannon D.; Aycock, Robert A.

    2001-01-01

    Arnold Air Force Base (AAFB) occupies about 40,000 acres in Coffee and Franklin Counties, Tennessee. Numerous site-specific ground-water contamination investigations have been conducted at designated solid waste management units (SWMU?s) at AAFB. Several synthetic volatile organic compounds (VOC?s), primarily chlorinated solvents, have been identified in groundwater samples collected from monitoring wells near SWMU 8 in the Spring Creek area. During April and May 2000, a study of the groundwater resources in the Spring Creek area was conducted to determine if VOC?s from AAFB have affected local private water supplies and to advance understanding of the ground-water-flow system in this area. The study focused on sampling private wells located within the Spring Creek area that are used as a source of drinking water. Ground-water-flow directions were determined by measuring water levels in wells and constructing a potentiometric-surface map of the Manchester aquifer in the study area. Data were collected from a total of 35 private wells and 22 monitoring wells during the period of study. Depths to ground water were determined for 22 of the private wells and all 22 of the monitoring wells. The wells ranged in depth from 21 to 105 feet. Water-level altitudes ranged from 930 to 1,062 feet above sea level. Depths to water ranged from 8 to 83 feet below land surface. Water-quality samples were collected from 29 private wells which draw water from either gravel zones in the upper part of the Manchester aquifer, fractured bedrock in the lower part of the Manchester aquifer, or a combination of these two zones. Concentrations of 50 of the 55 VOC?s analyzed for were less than method detection limits. Chloroform, acetone, chloromethane, 2-butanone, and tetrachloroethylene were detected in concentrations exceeding the method detection limits. Only chloroform and acetone were detected in concentrations equal to or exceeding reporting limits. Chloroform was detected in a sample

  16. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion.

    Science.gov (United States)

    Zhou, Xiaobo; Helmers, Matthew J; Asbjornsen, Heidi; Kolka, Randy; Tomer, Mark D

    2010-01-01

    Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (PFS) to mitigate increases in NO3-N levels. The study, conducted at the Neal Smith National Wildlife Refuge (NSNWR) in central Iowa, consisted of a balanced incomplete block design with 12 watersheds and four watershed-scale treatments having different proportions and topographic positions of PFS planted in native prairie grasses: 100% rowcrop, 10% PFS (toeslope position), 10% PFS (distributed on toe and as contour strips), and 20 PFS (distributed on toe and as contour strips). All treatments were established in fall 2006 on watersheds that were under bromegrass (Bromus L.) cover for at least 10 yr. Nonperennial areas were maintained under a no-till 2-yr corn (Zea mays L.)--soybean [Glycine max. (L.) Merr.] rotation since spring 2007. Suction lysimeter and shallow groundwater wells located at upslope and toeslope positions were sampled monthly during the growing season to determine NO3-N concentration from 2005 to 2008. The results indicated significant increases in NO3-N concentration in soil and groundwater following grassland-to-cropland conversion. Nitrate-nitrogen levels in the vadose zone and groundwater under PFS were lower compared with 100% cropland, with the most significant differences occurring at the toeslope position. During the years following conversion, PFS mitigated increases in subsurface nitrate, but long-term monitoring is needed to observe and understand the full response to land-use conversion.

  17. Geospatial Data Used in Water-Level and Land-Subsidence Studies in the Mojave River and Morongo Groundwater Basins for 2008

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — During 2008, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo groundwater basins....

  18. Geospatial Data Used in Water-Level and Land-Subsidence Studies in the Mojave River and Morongo Groundwater Basins for 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — During 2006, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo ground-water basins....

  19. A technique for estimating ground-water levels at sites in Rhode Island from observation-well data

    Science.gov (United States)

    Socolow, Roy S.; Frimpter, Michael H.; Turtora, Michael; Bell, Richard W.

    1994-01-01

    Estimates of future high, median, and low ground- water levels are needed for engineering and architectural design decisions and for appropriate selection of land uses. For example, the failure of individual underground sewage-disposal systems due to high ground-water levels can be prevented if accurate water-level estimates are available. Estimates of extreme or average conditions are needed because short duration preconstruction obser- vations are unlikely to be adequately represen- tative. Water-level records for 40 U.S. Geological Survey observation wells in Rhode Island were used to describe and interpret water-level fluctuations. The maximum annual range of water levels average about 6 feet in sand and gravel and 11 feet in till. These data were used to develop equations for estimating future high, median, and low water levels on the basis of any one measurement at a site and records of water levels at observation wells used as indexes. The estimating technique relies on several assumptions about temporal and spatial variations: (1) Water levels will vary in the future as they have in the past, (2) Water levels fluctuate seasonally (3) Ground-water fluctuations are dependent on site geology, and (4) Water levels throughout Rhode Island are subject to similar precipitation and climate. Comparison of 6,697 estimates of high, median, and low water levels (depth to water level exceeded 95, 50, and 5 percent of the time, respectively) with the actual measured levels exceeded 95, 50, and 5 percent of the time at 14 sites unaffected by pumping and unknown reasons, yielded mean squared errors ranging from 0.34 to 1.53 square feet, 0.30 to 1.22 square feet, and 0.32 to 2.55 square feet, respectively. (USGS)

  20. Groundwater level forecasting using an artificial neural network trained with particle swarm optimization.

    Science.gov (United States)

    Tapoglou, E.; Trichakis, I. C.; Dokou, Z.; Karatzas, G. P.

    2012-04-01

    period is minimal. Finally, climate change scenarios were examined, based on the prediction that on the island of Crete during the period of 2010-2040, it will be a 12(±25)% average reduction in precipitation and a 1.9(±0.9)oC increase in mean temperature (Tsanis et al., 2011). In order to study these scenarios, data time series were created for the period 2010-2020, using a stochastic weather generator for three cases (best, worst and average case scenarios). The prediction results indicate a significant negative effect on the groundwater level only for the worst case scenario (37% reduction in precipitation), while in the other cases the results vary from neutral to positive.

  1. Groundwater Quality Assessment Based on Geographical Information System and Groundwater Quality Index

    Directory of Open Access Journals (Sweden)

    Zahra Derakhshan

    2015-06-01

    Full Text Available Iran is located in an arid and semi-arid part of the world. Accordingly, the management of the water resources in the country is a priority. In this regard, determining the quality and pollution of surface water and groundwater is very important, especially in areas where groundwater resources are used for drinking. Groundwater quality index (GQI checks the components of the available water with various quality levels. To assess the quality of drinking groundwater of Yazd-Ardakan plain according to GQI in geographical information system (GIS environment, the electrical conductivity, sodium, calcium, magnesium, chlorine, pH, sodium adsorption ratio, bicarbonate, sulfate, potassium, water hardness, and all substances dissolved in the waters of 80 wells were determined. The samples were obtained from Yazd Regional Water Organization from 2005 to 2014. Using this data, the map components were plotted by Kriging geostatistical method. Then, the map of GQI was prepared after normalizing each map component, switching to a rating map, and extracting the weight of each component from the rating map. Based on the GQI index map, the index point which was 87 in 2005 has increased to 81 in 2014. These maps show a decline in groundwater quality from west to the east region. This decline in groundwater quality is due to the existence of Neogene Organizations in the east and geomorphologic unit of the bare epandage pediment in the west. The map removal and single-parameter sensitivity analysis showed that GQI index in Yazd-Ardakan plain is more sensitive to the components of electrical conductivity (EC, total dissolved solids (TDS, and total hardness (TH. Therefore, these components should be monitored more carefully and repeatedly.

  2. Vulnerability of topography-limited and recharge-limited groundwater systems to sea-level rise-induced salinization

    Science.gov (United States)

    Michael, H. A.; Byron, L. A.; Feinson, L. S.; Voss, C. I.; Russoniello, C. J.

    2012-12-01

    The effects of rising sea level on the hydraulic balance between aquifers and the ocean threaten freshwater resources and aquatic ecosystems along many world coastlines. Understanding both the vulnerability of groundwater systems to these changes and the primary factors that determine the magnitude of system response is critical to developing effective management plans in coastal zones. The rate and magnitude of salinization of fresh groundwater due to lateral seawater intrusion and changes in groundwater flow to the sea were assessed over a range of hydrogeologic settings. A primary factor affecting vulnerability is whether the system is recharge-limited or topography-limited. Results of two-dimensional variable-density groundwater-flow and salt-transport simulations indicate that the response of recharge-limited systems is largely minimal, whereas topography-limited systems are vulnerable for various combinations of permeability, vertical anisotropy in permeability, and recharge. World coastlines were classified according to system type as a vulnerability indicator. Results indicate that more than 50 percent of world coastlines are topography-limited over the range of cases tested. Central coastal Bangladesh is an example of a primarily topography-limited system that is highly vulnerable to impacts of sea-level rise as a result of its low elevation, dense population, and extensive groundwater use. Complexities of geologic heterogeneity and salinization processes, including storm-surge overtopping and accelerated salinization rates due to pumping, were considered. Results indicate that geologic heterogeneity has a strong control on the current and evolving pattern of salinity. The process of lateral intrusion can be slow, such that the current salinity distribution may still be changing in response to past sea-level rise. Vertical intrusion from above, where it occurs, is faster, and pumping can accelerate both mechanisms. Bangladesh vulnerability analyses are

  3. Current (2004-07) Conditions and Changes in Ground-Water Levels from Predevelopment to 2007, Southern High Plains Aquifer, East-Central New Mexico-Curry County, Portales, and Causey Lingo Underground Water Basins

    Science.gov (United States)

    Tillery, Anne

    2008-01-01

    The Southern High Plains aquifer is the principal aquifer in Curry and Roosevelt Counties, N. Mex., and primary source of water in southeastern New Mexico. Successful water-supply planning for New Mexico's Southern High Plains requires knowledge of the current aquifer conditions and a context to estimate future trends given current aquifer-management policy. This report provides a summary of the current (2007) water-level status of the Southern High Plains aquifer in New Mexico, including a basis for estimating future trends by comparison with historical conditions. This report includes estimates of the extent of ground-water level declines in the Curry County, Portales, and Causey-Lingo Ground-water Management Area parts of the High Plains Aquifer in eastern New Mexico since predevelopment. Maps representing 2007 water levels, water-level declines, aquifer saturated thickness, and depth to water accompanied by hydrographs from representative wells for the Southern High Plains aquifer in the Curry County, Portales, and Causey Lingo Underground Water Basins were prepared in cooperation with the New Mexico Office of the State Engineer. The results of this mapping show the water level declined as much as 175 feet in the study area at rates as high as 1.76 feet per year.

  4. Functional gene array-based analysis of microbial community structure in groundwaters with a gradient of contaminant levels

    Energy Technology Data Exchange (ETDEWEB)

    Waldron, P.J.; Wu, L.; Van Nostrand, J.D.; Schadt, C.W.; Watson, D.B.; Jardine, P.M.; Palumbo, A.V.; Hazen, T.C.; Zhou, J.

    2009-06-15

    To understand how contaminants affect microbial community diversity, heterogeneity, and functional structure, six groundwater monitoring wells from the Field Research Center of the U.S. Department of Energy Environmental Remediation Science Program (ERSP; Oak Ridge, TN), with a wide range of pH, nitrate, and heavy metal contamination were investigated. DNA from the groundwater community was analyzed with a functional gene array containing 2006 probes to detect genes involved in metal resistance, sulfate reduction, organic contaminant degradation, and carbon and nitrogen cycling. Microbial diversity decreased in relation to the contamination levels of the wells. Highly contaminated wells had lower gene diversity but greater signal intensity than the pristine well. The microbial composition was heterogeneous, with 17-70% overlap between different wells. Metal-resistant and metal-reducing microorganisms were detected in both contaminated and pristine wells, suggesting the potential for successful bioremediation of metal-contaminated groundwaters. In addition, results of Mantel tests and canonical correspondence analysis indicate that nitrate, sulfate, pH, uranium, and technetium have a significant (p < 0.05) effect on microbial community structure. This study provides an overall picture of microbial community structure in contaminated environments with functional gene arrays by showing that diversity and heterogeneity can vary greatly in relation to contamination.

  5. High-level mapping of cyberterrorism to the OODA Loop

    CSIR Research Space (South Africa)

    Veerasamy, N

    2010-04-01

    Full Text Available is to succinctly represent some of the psychological and technical issues relating to cyberterrorism. The OODA loop will be utilised to convey these ideas as well mapping to other relevant fields like the Information Hierarchy. Overall, various components...

  6. Mapping farm animal welfare education at university level in Europe

    NARCIS (Netherlands)

    Illmann, G.; Keeling, L.; Melisova, M.; Simeckova, M.; Ilieski, V.; Winckler, C.; Kostal, L.; Meunier-Salaun, M.; Mihina, S.; Spoolder, H.A.M.

    2014-01-01

    The aim of this study was to map farm animal welfare university education in an enlarged Europe with emphasis on identifying existing differences and gaps. Information on 210 courses dealing with farm animal welfare from 98 universities in 26 European countries were obtained. Statistical analysis

  7. Mapping farm animal welfare education at university level in Europe

    NARCIS (Netherlands)

    Illmann, G.; Keeling, L.; Melisova, M.; Simeckova, M.; Ilieski, V.; Winckler, C.; Kostal, L.; Meunier-Salaun, M.; Mihina, S.; Spoolder, H.A.M.

    2014-01-01

    The aim of this study was to map farm animal welfare university education in an enlarged Europe with emphasis on identifying existing differences and gaps. Information on 210 courses dealing with farm animal welfare from 98 universities in 26 European countries were obtained. Statistical analysis wa

  8. Enhancing arsenic removal from groundwater at household level with naturally occurring iron

    Directory of Open Access Journals (Sweden)

    Anitha Kumari Sharma

    2016-06-01

    Full Text Available A supply of drinking water low in Arsenic (As prevents arsenic poisoning. The presence of high concentrations of iron (Fe in groundwater under the alluvial plains of the large rivers in Southeast Asia is a prerequisite for the simple removal of As. This study investigated the mechanisms and possibilities for enhancing As removal with naturally occurring Fe in a reliable, low cost and sustainable way. The results of the study show that As removal with Fe is greatly enhanced by the addition of an oxidizing agent (preferably KMnO4 immediately after the pumping of groundwater. Further enhancement of As removal in the presence of Fe can be achieved by adding a small volume of a concentrated basic solution of MnO4- and AlO2-, which has a combined oxidation, coagulation and buffering capacity. Best results were obtained when this solution was mixed with the groundwater immediately after its pumping until a pale pink color appeared. Maximum required reaction time was 10 minutes and subsequent filtration of the water was able to reduce the As concentration to near zero. Concentrations of MnO4- and AlO2- can be varied in the solution to achieve sufficient As removal to suit different Fe/As ratios and the presence of interfering co-occurring anions.

  9. Salinity mapping of coastal groundwater aquifers using hydrogeochemical and geophysical methods: a case study from north Kelantan, Malaysia

    Science.gov (United States)

    Samsudin, A. R.; Haryono, A.; Hamzah, U.; Rafek, A. G.

    2008-10-01

    Integrated hydrogeochemical and geophysical methods were used to study the salinity of groundwater aquifers along the coastal area of north Kelantan. For the hydrogeochemical investigation, analysis of major ion contents of the groundwater was conducted, and other chemical parameters such as pH and total dissolved solids were also determined. For the geophysical study, both geoelectrical resistivity soundings and reflection seismic surveys were conducted to determine the characteristics of the subsurface and groundwater contained within the aquifers. The pH values range from 6.2 to 6.8, indicating that the groundwater in the study area is slightly acidic. Low content of chloride suggests that the groundwater in the first aquifer is fresh, with an average concentration of about 15.8 mg/l and high geoelectrical resistivity (>45 ohm m). On the other hand, the groundwater in the second aquifer is brackish, with chloride concentration ranging from 500 mg/l to 3,600 mg/l and very low geoelectrical resistivity (1,000 mg/l). The groundwater in the third aquifer is fresh, with chloride concentrations generally ranging from 2 mg/l to 210 mg/l and geoelectrical resistivity of greater than 45 ohm m. Fresh and saltwater interface in the first aquifer is generally located directly in the area of the coast, but, for the second aquifer, both hydrogeochemical and geoelectrical resistivity results indicate that the fresh water and saltwater interface is located as far as 6 km from the beach. The considerable chloride ion content initially suggests that the salinity of the groundwater in the second aquifer is probably caused by the intrusion of seawater. However, continuous monitoring of the chloride content of the second aquifer indicated no significant changes with time, from which it can be inferred that the salinity of the groundwater is not affected by seasonal seawater intrusion. Schoeller diagrams illustrate that sulphate concentrations of the groundwater of the second aquifer

  10. MAP17 and SGLT1 protein expression levels as prognostic markers for cervical tumor patient survival.

    Directory of Open Access Journals (Sweden)

    Marco Perez

    Full Text Available MAP17 is a membrane-associated protein that is overexpressed in human tumors. Because the expression of MAP17 increases reactive oxygen species (ROS generation through SGLT1 in cancer cells, in the present work, we investigated whether MAP17 and/or SGLT1 might be markers for the activity of treatments involving oxidative stress, such as cisplatin or radiotherapy. First, we confirmed transcriptional alterations in genes involved in the oxidative stress induced by MAP17 expression in HeLa cervical tumor cells and found that Hela cells expressing MAP17 were more sensitive to therapies that induce ROS than were parental cells. Furthermore, MAP17 increased glucose uptake through SGLT receptors. We then analyzed MAP17 and SGLT1 expression levels in cervical tumors treated with cisplatin plus radiotherapy and correlated the expression levels with patient survival. MAP17 and SGLT1 were expressed in approximately 70% and 50% of cervical tumors of different types, respectively, but they were not expressed in adenoma tumors. Furthermore, there was a significant correlation between MAP17 and SGLT1 expression levels. High levels of either MAP17 or SGLT1 correlated with improved patient survival after treatment. However, the patients with high levels of both MAP17 and SGLT1 survived through the end of this study. Therefore, the combination of high MAP17 and SGLT1 levels is a marker for good prognosis in patients with cervical tumors after cisplatin plus radiotherapy treatment. These results also suggest that the use of MAP17 and SGLT1 markers may identify patients who are likely to exhibit a better response to treatments that boost oxidative stress in other cancer types.

  11. Unbiased Group-Level Statistical Assessment of Independent Component Maps by Means of Automated Retrospective Matching

    NARCIS (Netherlands)

    Langers, Dave R. M.

    2010-01-01

    This report presents and validates a method for the group-level statistical assessment of independent component analysis (ICA) outcomes. The method is based on a matching of individual component maps to corresponding aggregate maps that are obtained from concatenated data. Group-level statistics are

  12. The RTL Binding and Mapping Approach of VHDL High—Level Synthesis System HLS/BIT

    Institute of Scientific and Technical Information of China (English)

    颜宗福; 刘明业

    1996-01-01

    This paper describes a VHDL high-level synthesis system HLS/BIT with emphasis on its register-transfer level(RTL)binding and technology mapping subsystem.In more detail,the component instantiation mechanism and the knowledge-driven approach to RTL technology mapping are also presented.

  13. Atomic-level mapping of antibody epitopes on a GPCR.

    Science.gov (United States)

    Paes, Cheryl; Ingalls, Jada; Kampani, Karan; Sulli, Chidananda; Kakkar, Esha; Murray, Meredith; Kotelnikov, Valery; Greene, Tiffani A; Rucker, Joseph B; Doranz, Benjamin J

    2009-05-27

    Epitopes that define the immunodominant regions of conformationally complex integral membrane proteins have been difficult to reliably delineate. Here, a high-throughput approach termed shotgun mutagenesis was used to map the binding epitopes of five different monoclonal antibodies targeting the GPCR CCR5. The amino acids, and in some cases the atoms, that comprise the critical contact points of each epitope were identified, defining the immunodominant structures of this GPCR and their physicochemistry.

  14. Low Level Caesium Mapping in Latvia Anno 1996

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    1999-01-01

    In Latvia the caesium-137 contamination from the Chernobyl accident and from the nuclear weapon tests in the 1960´es is very low. Conventional techniques for extracting information from the measured spectra cannot be used here. Therefore a new, sensitive technique - the pseudo concentration method...... - was developed, and maps could be produced for several regions in Latvia measured with airborne gamma-ray spectrometry in 1996....

  15. A numerical model to evaluate potential impacts of sea-level rise on groundwater resources in the Delaware coastal plain

    Science.gov (United States)

    He, C.; McKenna, T. E.; Wang, L.

    2013-12-01

    Sea level rise on the U.S. East Coast has accelerated much faster than in other parts of the world. In Delaware, the estimated sea level could rise as high as 1.5 meters by the year 2100 based on the information in IPCC (2007) and CCSP (2009). In this study, we used a 3-D variable-density groundwater flow model to study the movement of the fresh-water/salt-water interface and water table changes due to sea-level rise. Rather than developing a site-specific model, we analyzed the geospatial features of a serious of sub-watersheds along the coastline of the Delaware Estuary in Delaware using ArcGIS and constructed a representative model to capture the generalized flow patterns and saltwater intrusion rates that occur in typical area. Different scenarios with varying parameters were simulated. The simulation results were then applied to the Delaware River region to evaluate potential impacts of groundwater level changes on the potential land lose.

  16. Simulation of groundwater and nuclide transport in the near-field of the high-level radioactive waste repository with TOUGHREACT

    Institute of Scientific and Technical Information of China (English)

    LI Xun; YANG Zeping; ZHENG Zhihong; WU Hongmei

    2008-01-01

    In order to know the mechanism of groundwater transport and the variation of ion concentrations in the near-field of the high-level radioactive waste repository, the whole process was simulated by EOS3 module of TOUGHREACT. Generally, the pH and cation concentrations vary obviously in the near-field saturated zone due to interaction between groundwater and bentonite. Moreover, the simulated results showed that calcite precipitation could not cause obvious variations in the porosity of media in the near-filed if the chemical components and their concentrations of groundwater and bentonite pore water are similar to those used in this study.

  17. Optimization of Map Compilation for County-level Land Consolidation Planning

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Based on practice of the land consolidation planning in Changfeng County of Hefei City,taking full account of reality of land consolidation and its significance as livelihood project,we analyzed map compilation procedure.In combination with actual effect of land consolidation,we carried out consolidation assessment of same elements by overall planning method,and optimized the map compilation for county-level land consolidation planning.Results show that planning map of land consolidation potential is to be improved and legends should be merged.After consolidation of legends,it is convenient to apply in potential planning map and solve complicated problem of reading maps.

  18. Toxic Levels of Some Heavy Metals in Drinking Groundwater in Dakahlyia Governorate, Egypt in the Year 2010

    Directory of Open Access Journals (Sweden)

    RA Mandour

    2011-03-01

    Full Text Available Fifty-four drinking groundwater samples were collected in April 2010 from some districts of the Dakahlyia governorate, Egypt. The water samples were analyzed by atomic absorption spectrophotometer for iron, manganese, lead, nickel, chromium, zinc, copper, cobalt and cadmium concentrations. All samples but two were found suitable for drinking; from the water sample from Aga district showed slightly higher levels of cadmium and nickel (Ikhtab and Feshbena than other areas; the concentrations were higher than the permissible limits of Egyptian Ministry of Health and World Health Organization.

  19. Response of the accumulation of proline in the bodies of Populus euphratica to the change of groundwater level at the lower reaches of Tarim River

    Institute of Scientific and Technical Information of China (English)

    CHEN Yaning; CHEN Yapeng; LI Weihong; ZHANG Hongfeng

    2003-01-01

    The content of proline in the plant bodies is closely related to the converse-succession-resistant capability of the plants. In this paper, the relationship between the proline accumulation in the bodies of Populus euphratica and the change of groundwater level is analyzed by taking Populus euphratica, the main community-building species of the desert riparian forests along the Tarim River, as the research object. The research results show that the accumulation of proline in the bodies of Populus euphratica is closely related to the change of groundwater level gradient under drought stress, it increases with the drawdown of groundwater level and the increase of moisture stress degree; the accumulation of proline in the bodies of Populus euphratica has two extremely high points at the groundwater depth ranges of 3.64-5.14 m and 9.46-10.16 m. Combining the field investigation and the analysis of the plots, it is considered that the groundwater level of 3.5-4.5 m is rational for the growth of Populus euphratica. The stress groundwater depth for the normal growth and the critical one for the survival of Populus euphratica are below 4.5 m and 9-10 m respectively at the lower reaches of the Tarim River.

  20. 3-D MAPPING TECHNOLOGIES FOR HIGH LEVEL WASTE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    Marzolf, A.; Folsom, M.

    2010-08-31

    This research investigated four techniques that could be applicable for mapping of solids remaining in radioactive waste tanks at the Savannah River Site: stereo vision, LIDAR, flash LIDAR, and Structure from Motion (SfM). Stereo vision is the least appropriate technique for the solids mapping application. Although the equipment cost is low and repackaging would be fairly simple, the algorithms to create a 3D image from stereo vision would require significant further development and may not even be applicable since stereo vision works by finding disparity in feature point locations from the images taken by the cameras. When minimal variation in visual texture exists for an area of interest, it becomes difficult for the software to detect correspondences for that object. SfM appears to be appropriate for solids mapping in waste tanks. However, equipment development would be required for positioning and movement of the camera in the tank space to enable capturing a sequence of images of the scene. Since SfM requires the identification of distinctive features and associates those features to their corresponding instantiations in the other image frames, mockup testing would be required to determine the applicability of SfM technology for mapping of waste in tanks. There may be too few features to track between image frame sequences to employ the SfM technology since uniform appearance may exist when viewing the remaining solids in the interior of the waste tanks. Although scanning LIDAR appears to be an adequate solution, the expense of the equipment ($80,000-$120,000) and the need for further development to allow tank deployment may prohibit utilizing this technology. The development would include repackaging of equipment to permit deployment through the 4-inch access ports and to keep the equipment relatively uncontaminated to allow use in additional tanks. 3D flash LIDAR has a number of advantages over stereo vision, scanning LIDAR, and SfM, including full frame

  1. Aerodynamic map for soft and hard hypersonic level flight in near space

    Institute of Scientific and Technical Information of China (English)

    Ruifeng Hu; Ziniu Wu; Zhe Wu; Xiaoxin Wang; Zhongwei Tian

    2009-01-01

    In this note, we design a velocity-altitude map for hypersonic level flight in near space of altitude 20-100 km. This map displays aerodynamic-related parameters associated with near space level flight, schematically or quantitatively. Various physical conditions for the near-space level flight are then characterized, including laminar or turbulent flow, rarefaction or continuous flow, aerodynamic heating, as well as conditions for sustaining level flight with and without orbital effect. This map allows one to identify conditions to have soft flight or hard flight, and this identification would be helpful for making correct planning on detailed studies of aerodynamics or making initial design of near space vehicles.

  2. The use of Time Domain Electromagnetic method and Continuous Vertical Electrical Sounding to map groundwater salinity in the Barotse sub-basin, Zambia

    Science.gov (United States)

    Chongo, M.; Wibroe, J.; Staal-Thomsen, K.; Moses, M.; Nyambe, I. A.; Larsen, F.; Bauer-Gottwein, P.

    This paper describes the results from the application of two geophysical exploration techniques, Time Domain Electromagnetic (TDEM) and Continuous Vertical Electrical Sounding (CVES) that have proved effective in mapping groundwater salinity variations within the sedimentary formations of the Barotse sub basin in the Western Province of Zambia. TDEM was used to map groundwater salinity variations on a regional scale, whereas CVES was used at the local scale to investigate freshwater-saltwater distribution in an ephemeral river valley. On a regional scale, salt water occurrence was shown to be present mainly on the south-eastern portions of the basin, which are situated in a rift that forms a tripe junction with the East African Rift Valley. The general geophysical model indicates an aquifer with saline water with a thickness of about 40 m with resistivity variations less than 35 Ωm (more than 500 mg/l of Cl - based on a formation factor of 5), overlain by an unconfined freshwater aquifer of about 10 m thickness with resistivities in excess of 70 Ωm (i.e. less than 250 mg/l of Cl - based on a formation factor of 5). The origin of the saline water is hypothesized to be related to the evapo-concentration of salts in interdune deposits, which were subsequently buried due to dune migration about 32 to 4 thousands of years ago or kilo annums (ka). The occurrence of saline groundwater could also possibly be linked to evaporation of a former Lake Paleo Makgadikgadi, an extensive endorheic lake system that once covered large parts of Southern Africa. Locally, a thin freshwater aquifer was observed in an ephemeral river valley, indicating recent recharge of river water into a pre-existing saline environment.

  3. Changes between early development (1930–60) and recent (2005–15) groundwater-level altitudes and dissolved-solids and nitrate concentrations In and near Gaines, Terry, and Yoakum Counties, Texas

    Science.gov (United States)

    Thomas, Jonathan V.; Teeple, Andrew; Payne, Jason; Ikard, Scott

    2016-06-21

    Llano Estacado Underground Water Conservation District, Sandy Land Underground Water Conservation District, and South Plains Underground Water Conservation District manage groundwater resources in a part of west Texas near the Texas-New Mexico State line. Declining groundwater levels have raised concerns about the amount of available groundwater in the study area and the potential for water-quality changes resulting from dewatering and increased vertical groundwater movement between adjacent water-bearing units.

  4. Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, January 2006 to January 2010

    Science.gov (United States)

    Hansen, Cristi V.; Aucott, Walter R.

    2010-01-01

    A part of the Equus Beds aquifer in southwestern Harvey County and northwestern Sedgwick County was developed to supply water to residents of Wichita and for irrigation in south-central Kansas. Groundwater pumping for city and agricultural use caused water levels to decline in a large part of the aquifer northwest of Wichita. In 1965, the city of Wichita began using water from Cheney Reservoir in addition to water from the Equus Beds aquifer to meet the city's increasing demand for water. Irrigation pumpage in the area increased substantially during the 1970s and 1980s and contributed to the water-level declines. Water-level declines reached their maximum to date in October 1992.

  5. Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, January 2016

    Science.gov (United States)

    Klager, Brian J.

    2016-12-29

    The Equus Beds aquifer in south-central Kansas, which is part of the High Plains aquifer, serves as a source of water for municipal and agricultural users in the area. The city of Wichita has used the Equus Beds aquifer as one of its primary water sources since the 1940s. The aquifer in and around Wichita’s well field reached historically low water levels in 1993, prompting the city to adopt new water-use and conservation strategies to ensure future water supply needs were met. Part of the plan was to initiate a managed aquifer recharge program called the Equus Beds Aquifer Storage and Recovery project. The goal of the managed aquifer recharge program is to artificially recharge the Equus Beds aquifer with treated water from the Little Arkansas River. As part of the Equus Beds Aquifer Storage and Recovery project, the city of Wichita and the U.S. Geological Survey have partnered in a long-term cooperative study to monitor and describe the quantity and quality of the water in the Equus Beds aquifer and the Little Arkansas River.The city of Wichita, the Equus Beds Groundwater Management District No. 2, the Kansas Department of Agriculture–Division of Water Resources, and the U.S. Geological Survey collected groundwater levels in numerous wells screened in the Equus Beds aquifer in the area in and around Wichita’s well field in January 2016. The measurements were used to interpolate potentiometric surfaces for shallow and deep parts of the aquifer in the study area. These potentiometric surfaces were compared with potentiometric surfaces from previous years to estimate changes in water levels and storage volume in the study area.Groundwater levels were generally higher in January 2016 than they were in January 2015. On average, in January 2016, groundwater levels in the shallow part of the aquifer were about 3.4 feet higher and groundwater levels in the deep part of the aquifer were about 3.8 feet higher than in January 2015. The volume of water stored in the

  6. Simulation of groundwater level variations using wavelet combined with neural network, linear regression and support vector machine

    Science.gov (United States)

    Ebrahimi, Hadi; Rajaee, Taher

    2017-01-01

    Simulation of groundwater level (GWL) fluctuations is an important task in management of groundwater resources. In this study, the effect of wavelet analysis on the training of the artificial neural network (ANN), multi linear regression (MLR) and support vector regression (SVR) approaches was investigated, and the ANN, MLR and SVR along with the wavelet-ANN (WNN), wavelet-MLR (WLR) and wavelet-SVR (WSVR) models were compared in simulating one-month-ahead of GWL. The only variable used to develop the models was the monthly GWL data recorded over a period of 11 years from two wells in the Qom plain, Iran. The results showed that decomposing GWL time series into several sub-time series, extremely improved the training of the models. For both wells 1 and 2, the Meyer and Db5 wavelets produced better results compared to the other wavelets; which indicated wavelet types had similar behavior in similar case studies. The optimal number of delays was 6 months, which seems to be due to natural phenomena. The best WNN model, using Meyer mother wavelet with two decomposition levels, simulated one-month-ahead with RMSE values being equal to 0.069 m and 0.154 m for wells 1 and 2, respectively. The RMSE values for the WLR model were 0.058 m and 0.111 m, and for WSVR model were 0.136 m and 0.060 m for wells 1 and 2, respectively.

  7. Effect of sea-level rise and climate change on groundwater salinity and agro-hydrology in a low coastal region of the Netherlands

    NARCIS (Netherlands)

    Stuyt, L.C.P.M.; Kabat, P.; Postma, J.; Pomper, A.B.

    1995-01-01

    Scenario studies were carried out to predict the effects of doubled carbon dioxide levels, a 1 °C temperature increase and a 1.2 m sea level rise on seepage, groundwater and crop production. Climatic change was simulated, showing increased precipitation. Simulation of effects of sea level rise on

  8. Groundwater and Terrestrial Water Storage

    Science.gov (United States)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2011-01-01

    Most people think of groundwater as a resource, but it is also a useful indicator of climate variability and human impacts on the environment. Groundwater storage varies slowly relative to other non-frozen components of the water cycle, encapsulating long period variations and trends in surface meteorology. On seasonal to interannual timescales, groundwater is as dynamic as soil moisture, and it has been shown that groundwater storage changes have contributed to sea level variations. Groundwater monitoring well measurements are too sporadic and poorly assembled outside of the United States and a few other nations to permit direct global assessment of groundwater variability. However, observational estimates of terrestrial water storage (TWS) variations from the GRACE satellites largely represent groundwater storage variations on an interannual basis, save for high latitude/altitude (dominated by snow and ice) and wet tropical (surface water) regions. A figure maps changes in mean annual TWS from 2009 to 2010, based on GRACE, reflecting hydroclimatic conditions in 2010. Severe droughts impacted Russia and the Amazon, and drier than normal weather also affected the Indochinese peninsula, parts of central and southern Africa, and western Australia. Groundwater depletion continued in northern India, while heavy rains in California helped to replenish aquifers that have been depleted by drought and withdrawals for irrigation, though they are still below normal levels. Droughts in northern Argentina and western China similarly abated. Wet weather raised aquifer levels broadly across western Europe. Rains in eastern Australia caused flooding to the north and helped to mitigate a decade long drought in the south. Significant reductions in TWS seen in the coast of Alaska and the Patagonian Andes represent ongoing glacier melt, not groundwater depletion. Figures plot time series of zonal mean and global GRACE derived non-seasonal TWS anomalies (deviation from the mean of

  9. Global mapping of nonseismic sea level oscillations at tsunami timescales

    Science.gov (United States)

    Vilibić, Ivica; Šepić, Jadranka

    2017-01-01

    Present investigations of sea level extremes are based on hourly data measured at coastal tide gauges. The use of hourly data restricts existing global and regional analyses to periods larger than 2 h. However, a number of processes occur at minute timescales, of which the most ruinous are tsunamis. Meteotsunamis, hazardous nonseismic waves that occur at tsunami timescales over limited regions, may also locally dominate sea level extremes. Here, we show that nonseismic sea level oscillations at tsunami timescales (sea level extremes, up to 50% in low-tidal basins. The intensity of these oscillations is zonally correlated with mid-tropospheric winds at the 99% significance level, with the variance doubling from the tropics and subtropics to the mid-latitudes. Specific atmospheric patterns are found during strong events at selected locations in the World Ocean, indicating a globally predominant generation mechanism. Our analysis suggests that these oscillations should be considered in sea level hazard assessment studies. Establishing a strong correlation between nonseismic sea level oscillations at tsunami timescales and atmospheric synoptic patterns would allow for forecasting of nonseismic sea level oscillations for operational use, as well as hindcasting and projection of their effects under past, present and future climates.

  10. Water-level changes and directions of ground-water flow in the shallow aquifer, Fallon area, Churchill County, Nevada

    Science.gov (United States)

    Seiler, R.L.; Allander, K.K.

    1993-01-01

    The Truckee-Carson-Pyramid Lake Water Rights Settlement Act of 1990 directed the U.S. Fish and Wildlife Service to acquire water rights for wetland areas in the Carson Desert, Nevada. The public is concerned that htis acquisition of water rights and delivery of the water directly to wildlife areas would result in less recharge to the shallow ground water in the Fallon area and cause domestic wells to go dry. In January 1992, the U.S. Geological Survey, in cooperation with U.S. Fish and Wildlife Service, began a study of the shallow ground-water system in the Fallon area in Churchill County, Nevada. A network of 126 wells in the study area was monitored. Between January and November 1992, water levels in most wells declined, usually less than 2 feet. The maximum measured decline over this period was 2.68 feet in a well near Stillwater Marsh. Between April and July, however, water levels rose in irrigated areas, typically 1 to 2 feet. Newlands Project water deliveries to the study area began soon after the turn of the century. Since then, water levels have risen more than 15 feet across much of the study area. Water lost from unlined irrigtiaon canals caused the stage in Big Soda Lake to rise nearly 60 feet; ground-water levels near the lake have risen 30 to 40 feet. The depth to water in most irrigated areas is now less than 10 feet. The altitude of the water table ranges from 4.025 feet above sea level 11 miles west of Fallon to 3,865 feet in the Stillwater Marsh area. Ground water flows eastward and divides; some flow goes to the northeast toward the Carson Sink and Stillwater areas, and some goes southeastward to Carson Lake.

  11. Tide-induced fluctuations of salinity and groundwater level in unconfined aquifers - Field measurements and numerical model

    Science.gov (United States)

    Levanon, Elad; Yechieli, Yoseph; Gvirtzman, Haim; Shalev, Eyal

    2017-08-01

    The responses of the fresh-saline water interface (FSI) and the groundwater level (GWL) to the Mediterranean Sea tide were monitored in the coastal aquifer of Israel, modeled numerically and analyzed using cross-correlation analysis. Different time-lags between sea level fluctuations and hydraulic head and salinity fluctuations were detected for the FSI and the GWL. At the FSI, the time-lag of hydraulic head behind the sea level is much shorter than the lag of the salinity at the same point. Surprisingly, similar time-lags behind the sea level were measured for both the hydraulic head at the GWL and the salinity at the FSI, both at the same distance from the shoreline. Results from a numerical model, simulating the flow and transport processes at the field scale, agree with field measurements. In both, the GWL and the salinity in the FSI fluctuate almost simultaneously, while the hydraulic head in the FSI reacts faster to sea level fluctuations. The actual movement of the fresh water body, which is controlled by the unsaturated flow in the capillary fringe ('capillary effect'), lags behind the pressure head fluctuations in the deeper parts of the aquifer, which is controlled by saturated parameters of the aquifer. The overall results agree with the conceptual mechanism suggested by Levanon et al. (2016), in which the effect of sea tide on the coastal groundwater system comprises two main processes: (1) tidal fluctuations at the sea floor boundary which cause pressure wave propagation into the aquifer, and (2) attenuation at the GWL due to the capillary effect which control also the change in the salinity and the actual movement of the FSI.

  12. Development og groundwater flow modeling techniques for the low-level radwaste disposal (III)

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Dae-Seok; Kim, Chun-Soo; Kim, Kyung-Soo; Park, Byung-Yoon; Koh, Yong-Kweon; Park, Hyun-Soo [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-12-01

    The project amis to establish the methodology of hydrogeologic assessment by the field application of the evaluation techniques gained and accumulated from the previous hydrogeological research works in Korea. The results of the project and their possible areas for application are (1) acquisition of detailed hydrogeologic information by using a borehole televiewer and a multipacker system, (2) establishing an integrated hydrogeological assessment method for fractured rocks, (3) acquisition of the fracture parameters for fracture modeling, (4) an inversion analysis of hydraulic parameters from fracture network modeling, (5) geostatistical methods for the spatial assignment of hydraulic parameters for fractured rocks, and (6) establishing the groundwater flow modeling procedure for a repository. 75 refs., 72 figs., 34 tabs. (Author)

  13. Comparison of Groundwater Level Models Based on Artificial Neural Networks and ANFIS

    Directory of Open Access Journals (Sweden)

    Nevenka Djurovic

    2015-01-01

    Full Text Available Water table forecasting plays an important role in the management of groundwater resources in agricultural regions where there are drainage systems in river valleys. The results presented in this paper pertain to an area along the left bank of the Danube River, in the Province of Vojvodina, which is the northern part of Serbia. Two soft computing techniques were used in this research: an adaptive neurofuzzy inference system (ANFIS and an artificial neural network (ANN model for one-month water table forecasts at several wells located at different distances from the river. The results suggest that both these techniques represent useful tools for modeling hydrological processes in agriculture, with similar computing and memory capabilities, such that they constitute an exceptionally good numerical framework for generating high-quality models.

  14. Comparison of Groundwater Level Models Based on Artificial Neural Networks and ANFIS

    Science.gov (United States)

    Domazet, Milka; Stricevic, Ruzica; Pocuca, Vesna; Spalevic, Velibor; Pivic, Radmila; Gregoric, Enika; Domazet, Uros

    2015-01-01

    Water table forecasting plays an important role in the management of groundwater resources in agricultural regions where there are drainage systems in river valleys. The results presented in this paper pertain to an area along the left bank of the Danube River, in the Province of Vojvodina, which is the northern part of Serbia. Two soft computing techniques were used in this research: an adaptive neurofuzzy inference system (ANFIS) and an artificial neural network (ANN) model for one-month water table forecasts at several wells located at different distances from the river. The results suggest that both these techniques represent useful tools for modeling hydrological processes in agriculture, with similar computing and memory capabilities, such that they constitute an exceptionally good numerical framework for generating high-quality models. PMID:26759830

  15. Bored boys, graffiti, and YouTube - tracing recent groundwater level changes in a Saudi Arabian cave

    Science.gov (United States)

    Michelsen, Nils; Dirks, Heiko; Schulz, Stephan; Kempe, Stephan; Schüth, Christoph

    2015-04-01

    The Dahl Hith cave is located approximately 30 km southeast of Riyadh, the capital of Saudi Arabia. In the past decades, the groundwater table exposed inside the cave became subject to appreciable changes. After a decline due to agricultural water abstraction for irrigation purposes, the water table exhibited a rapid rise in the last few years. Considering that most of the aquifers of the country show a depletion of the largely fossil groundwater, the mentioned rise is quite unusual. The area does not host an observation well, i.e., reliable data on the piezometric changes is hitherto not available. Hence, two uncommon data sources were used to reconstruct the water level changes: (1) YouTube videos and (2) graffiti inscriptions. (1) The cave is frequently visited by locals and expats from Riyadh and many visitors are willing to share their cave adventures on YouTube. Identifying certain reference points in the uploaded videos (e.g. specific boulders, cave graffiti) and estimating their position relative to the water table allows for an approximate reconstruction of the recent groundwater rise. Information on the observation time is derived from the uploading date. Occasionally, also the exact date of the visit is provided as part of the footage description. (2) Some people documented their visit by graffiti inscriptions. These do not only serve as a marker in the videos, but also contain genuine data on historic water levels: if written on parts of the cave wall, which are only accessible from the water, they indicate the water level at the time of their creation. Fortunately, some graffiti also feature the date of the visit. In order to improve the reliability of the water level estimations, measurements conducted in the course of own site visits in the past few years were considered for the evaluation. Also photographs taken during these surveys helped to improve the quality of the water level reconstruction. The described "Youtube Approach" could be interpreted

  16. Global mapping of nonseismic sea level oscillations at tsunami timescales

    Science.gov (United States)

    Vilibić, Ivica; Šepić, Jadranka

    2017-01-01

    Present investigations of sea level extremes are based on hourly data measured at coastal tide gauges. The use of hourly data restricts existing global and regional analyses to periods larger than 2 h. However, a number of processes occur at minute timescales, of which the most ruinous are tsunamis. Meteotsunamis, hazardous nonseismic waves that occur at tsunami timescales over limited regions, may also locally dominate sea level extremes. Here, we show that nonseismic sea level oscillations at tsunami timescales (tsunami timescales and atmospheric synoptic patterns would allow for forecasting of nonseismic sea level oscillations for operational use, as well as hindcasting and projection of their effects under past, present and future climates. PMID:28098195

  17. USGS Map service: Coastal Vulnerability to Sea-Level Rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The coastal vulnerability index (CVI)provides a preliminary overview, at a National scale, of the relative susceptibility of the Nation's coast to sea-level rise....

  18. USGS Map service: Coastal Vulnerability to Sea-Level Rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The coastal vulnerability index (CVI)provides a preliminary overview, at a National scale, of the relative susceptibility of the Nation's coast to sea-level rise....

  19. Generalized surficial geologic map of the Fort Irwin area, San Bernadino: Chapter B in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

    Science.gov (United States)

    Miller, David M.; Menges, Christopher M.; Lidke, David J.; Buesch, David C.

    2014-01-01

    The geology and landscape of the Fort Irwin area, typical of many parts of the Mojave Desert, consist of rugged mountains separated by broad alluviated valleys that form the main coarse-resolution features of the geologic map. Crystalline and sedimentary rocks, Mesozoic and older in age, form most of the mountains with lesser accumulations of Miocene sedimentary and volcanic rocks. In detail, the area exhibits a fairly complex distribution of surficial deposits resulting from diverse rock sources and geomorphology that has been driven by topographic changes caused by recent and active faulting. Depositional environments span those typical of the Mojave Desert: alluvial fans on broad piedmonts, major intermittent streams along valley floors, eolian sand dunes and sheets, and playas in closed valleys that lack through-going washes. Erosional environments include rocky mountains, smooth gently sloping pediments, and badlands in readily eroded sediment. All parts of the landscape, from regional distribution of mountains, valleys, and faults to details of degree of soil development in surface materials, are portrayed by the surficial geologic map. Many of these attributes govern infiltration and recharge, and the surface distribution of permeable rock units such as Miocene sedimentary and volcanic rocks provides a basis for evaluating potential groundwater storage. Quaternary faults are widespread in the Fort Irwin area and include sinistral, east-striking faults that characterize the central swath of the area and the contrasting dextral, northwest-striking faults that border the east and west margins. Bedrock distribution and thickness of valley-fill deposits are controlled by modern and past faulting, and faults on the map help to identify targets for groundwater exploration.

  20. Potential benefits of a spatially targeted regulation based on detailed N-reduction maps to decrease N-load from agriculture in a small groundwater dominated catchment.

    Science.gov (United States)

    Hansen, A L; Refsgaard, J C; Olesen, J E; Børgesen, C D

    2017-10-01

    Denmark must further decrease the N-load to coastal waters from agricultural areas to comply with the Baltic Sea Action Plan and the EU Water Framework Directive. A new spatially targeted regulation is under development that focuses on locating N-mitigation measures in areas with low natural reduction of nitrate (N-reduction). A key tool in this respect is N-reduction maps showing how much N is removed by natural reduction processes, i.e. the ratio between the N-load out of the catchment and the N-leaching from the root zone for each spatial unit within the catchment. For the 85 km(2) groundwater dominated Norsminde catchment in Denmark we have analysed the potential benefits of a spatially targeted regulation and how its efficiency is affected by uncertainty in the N-reduction map. Our results suggest that there are potential benefits of implementing a spatially targeted regulation compared to a spatially uniform regulation. The total N-load at the catchment outlet can be decreased up to 8% by relocating the existing agricultural practice according to the N-reduction map and thus without decrease fertilization inputs. A further decrease in N-load can be obtained by identifying target areas with low N-reduction where N-mitigation measures must be applied. Uncertainty on the N-reduction map is found to lower the efficiency of spatially targeted regulation. This uncertainty can be lowered substantially by using the mean of an ensemble of N-reduction maps. The uncertainty decreases with coarser spatial resolution of the N-reduction map, but this will at the same time decrease the benefit from spatially targeted regulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-05-01

    This document was written to provide guidance to managers and site operators on how ground-water transport codes should be selected for assessing burial site performance. There is a need for a formal approach to selecting appropriate codes from the multitude of potentially useful ground-water transport codes that are currently available. Code selection is a problem that requires more than merely considering mathematical equation-solving methods. These guidelines are very general and flexible and are also meant for developing systems simulation models to be used to assess the environmental safety of low-level waste burial facilities. Code selection is only a single aspect of the overall objective of developing a systems simulation model for a burial site. The guidance given here is mainly directed toward applications-oriented users, but managers and site operators need to be familiar with this information to direct the development of scientifically credible and defensible transport assessment models. Some specific advice for managers and site operators on how to direct a modeling exercise is based on the following five steps: identify specific questions and study objectives; establish costs and schedules for achieving answers; enlist the aid of professional model applications group; decide on approach with applications group and guide code selection; and facilitate the availability of site-specific data. These five steps for managers/site operators are discussed in detail following an explanation of the nine systems model development steps, which are presented first to clarify what code selection entails.

  2. Resolving discrepancies between hydraulic and chemical calibration data for seawater intrusion groundwater flow models by considering climate-driven sea level change.

    Energy Technology Data Exchange (ETDEWEB)

    J. Chapman; A. Hassan; K. Pohlmann

    2001-10-18

    Groundwater models of seawater intrusion environments can be calibrated using both hydraulic and chemical information. The possible impact of the long-term transient process of sea level change is difficult to identify, but important to accurate simulation of present conditions. The response times of the pressure and chemical fields to major fluctuations in sea level change are investigated

  3. Land subsidence induced by groundwater extraction and building damage level assessment-a case study of Datun,China

    Institute of Scientific and Technical Information of China (English)

    FENG Qi-yan; LIU Gang-jun; MENG Lei; FU Er-jiang; ZHANG Hai-rong; ZHANG Ke-fei

    2008-01-01

    As in many parts of the world, long-term excessive extraction of groundwater has caused significant land-surface subsidence in the residential areas of Datun coal mining district in East China. The recorded maximum level of subsidence in the area since 1976 to 2006 is 863 mm, and the area with an accumulative subsidence more than 200 mm has reached 33.1 km2 by the end of 2006. Over ten cases of building crack due to ground subsidence have already been observed. Spatial variation in ground subsidence often leads to a corresponding pattern of ground deformation. Buildings and underground infrastructures have been under a higher risk of damage in locations with greater differential ground deformation. Governmental guideline in China classifies building damages into four different levels, based on the observable measures such as the width of wall crack, the degree of door and window deformation, the degree of wall inclination and the degree of structural destruction. Building damage level (BDL) is estimated by means of ground deformation analysis in terms of variations in slope gradient and curvature. Ground deformation analysis in terms of variations in slope gradient has shown that the areas of BDL Ⅲ and BDL Ⅱ sites account for about 0.013 km2 and 0.284km2 respectively in 2006, and the predicted areas of BDL (define this first) Ⅲ and Ⅱ sites will be about 0.029 km2 and 0.423 km2respectively by 2010. The situation is getting worse as subsidence continues. That calls for effective strategies for subsidence mitigation and damage reduction, in terms of sustainable groundwater extraction, enhanced monitoring and the establishment of early warning systems.

  4. DPOAE level mapping for detecting noise-induced cochlear damage from short-duration music exposures.

    Science.gov (United States)

    Buckey, Jay C; Fellows, Abigail M; Clavier, Odile H; Allen, Lindsay V; Brooks, Chris A; Norris, Jesse A; Gui, Jiang; Meinke, Deanna K

    2015-01-01

    Distortion product otoacoustic emission (DPOAE) level mapping provides a comprehensive picture of cochlear responses over a range of DP frequencies and f₂/f₁ratios. We hypothesized that individuals exposed to high-level sound would show changes detectable by DPOAE mapping, but not apparent on a standard DP-gram. Thirteen normal hearing subjects were studied before and after attending music concerts. Pure-tone audiometry (500-8,000 Hz), DP-grams (0.3-10 kHz) at 1.22 ratio, and DPOAE level maps were collected prior to, as soon as possible after, and the day after the concerts. All maps covered the range of 2,000-6,000 Hz in DP frequency and from 1.3 to -1.3 in ratio using equi-level primary tone stimuli. Changes in the pure-tone audiogram were significant (P ≤ 0.01) immediately after the concert at 1,000 Hz, 4,000 Hz, and 6,000 Hz. The DP-gram showed significant differences only at f₂= 4,066 (P = 0.01) and f₂= 4,348 (P = 0.04). The postconcert changes were readily apparent both visually and statistically (P ≤ 0.01) on the mean DP level maps, and remained statistically significantly different from baseline the day after noise exposure although no significant changes from baseline were seen on the DP-gram or audiogram the day after exposure. Although both the DP-gram and audiogram showed recovery by the next day, the average DPOAE level maps remained significantly different from baseline. The mapping data showed changes in the cochlea that were not detected from the DP-gram obtained at a single ratio. DPOAE level mapping provides comprehensive information on subtle cochlear responses, which may offer advantages for studying and tracking noise-induced hearing loss (NIHL).

  5. Cross-species toxicogenomic analyses and phenotypic anchoring in response to groundwater low-level pollution.

    Science.gov (United States)

    Porreca, Immacolata; D'Angelo, Fulvio; Gentilcore, Daniela; Carchia, Emanuele; Amoresano, Angela; Affuso, Andrea; Ceccarelli, Michele; De Luca, Pasquale; Esposito, Libera; Guadagno, Francesco M; Mallardo, Massimo; Nardone, Antonio; Maccarone, Sergio; Pane, Francesca; Scarfò, Marzia; Sordino, Paolo; De Felice, Mario; Ambrosino, Concetta

    2014-12-05

    Comparison of toxicogenomic data facilitates the identification of deregulated gene patterns and maximizes health risk prediction in human. Here, we performed phenotypic anchoring on the effects of acute exposure to low-grade polluted groundwater using mouse and zebrafish. Also, we evaluated two windows of chronic exposure in mouse, starting in utero and at the end of lactation. Bioinformatic analysis of livers microarray data showed that the number of deregulated biofunctions and pathways is higher after acute exposure, compared to the chronic one. It also revealed specific profiles of altered gene expression in all treatments, pointing to stress response/mitochondrial pathways as major players of environmental toxicity. Of note, dysfunction of steroid hormones was also predicted by bioinformatic analysis and verified in both models by traditional approaches, serum estrogens measurement and vitellogenin mRNA determination in mice and zebrafish, respectively. In our report, phenotypic anchoring in two vertebrate model organisms highlights the toxicity of low-grade pollution, with varying susceptibility based on exposure window. The overlay of zebrafish and mice deregulated pathways, more than single genes, is useful in risk identification from chemicals implicated in the observed effects.

  6. Coseismic responses of groundwater levels in the Three Gorges well-network to the Wenchuan Ms8.0 earthquake

    Institute of Scientific and Technical Information of China (English)

    Chenglong Liu; Guangcai Wang; Weihua Zhang; Jiangchang Mei

    2009-01-01

    We systematically analyze coseismic responses and post-seismic characteristics of groundwater levels in the Three Gorges well-network to the Afs8.0 Wenchuan earthquake on 12 May 2008. The results indicate that these characteristics differ among wells. On the conditions of similar borehole configurations, the differences are associated with geological structural sites of wells, burial types of aquifers monitored, and transmissivities of aquifer systems. We explored coseismic and post-seismic step-rise and step-drop mechanical mechanisms and their implication to earthquake prediction. We validated the inference that the residual step-rise zone is a possible earthquake risk zone based on recent seismic activity on the Xianniishan fault in the area.

  7. Evaluation of Elevated Tritium Levels in Groundwater Downgradient from the 618-11 Burial Ground Phase I Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P.E.; Smith, R.M.; Williams, B.A.; Thompson, C.J.; Evans, J.C.; Hulstrom, L.C.

    2000-05-01

    This report describes the results of the preliminary investigation of elevated tritium in groundwater discovered near the 618-11 burial ground, located in the eastern part of the Hanford Site. Tritium in one well downgradient of the burial ground was detected at levels up to 8,140,000 pCi/L. The 618-11 burial ground received a variety of radioactive waste from the 300 Area between 1962 and 1967. The burial ground covers 3.5 hectare (8.6 acre) and contains trenches, large diameter caissons, and vertical pipe storage units. The burial ground was stabilized with a native sediment covering. The Energy Northwest reactor complex was constructed immediately east of the burial ground.

  8. Predictive models applied to groundwater level forecasting: a preliminary experience on the alluvial aquifer of the Magra River (Italy).

    Science.gov (United States)

    Brozzo, Gianpiero; Doveri, Marco; Lelli, Matteo; Scozzari, Andrea

    2010-05-01

    Computer-based decision support systems are getting a growing interest for water managing authorities and water distribution companies. This work discusses a preliminary experience in the application of computational intelligence in a hydrological modeling framework, regarding the study area of the alluvial aquifer of the Magra River (Italy). Two sites in the studied area, corresponding to two distinct groups of wells (Battifollo and Fornola) are managed by the local drinkable water distribution company (ACAM Acque), which serves the area of La Spezia, on the Ligurian coast. Battifollo has 9 wells with a total extraction rate of about 240 liters per second, while Fornola has 44 wells with an extraction rate of about 900 liters per second. Objective of this work is to make use of time series coming from long-term monitoring activities in order to assess the trend of the groundwater level with respect to a set of environmental and exploitation parameters; this is accomplished by the experimentation of a suitable model, eligible to be used as a predictor. This activity moves on from the modeling of the system behavior, based on a set of Input/Output data, in order to characterize it without necessarily a prior knowledge of any deterministic mechanism (system identification). In this context, data series collected by continuous hydrological monitoring instrumentation installed in the studied sites, together with meteorological and water extraction data, have been analyzed in order to assess the applicability and performance of a predictive model of the groundwater level. A mixed approach (both data driven and process-based) has been experimented on the whole dataset relating to the last ten years of continuous monitoring activity. The system identification approach presented here is based on the integration of an adaptive technique based on Artificial Neural Networks (ANNs) and a blind deterministic identification approach. According to this concept, the behavior of

  9. Mapping CMMI Level 2 to Scrum Practices: An Experience Report

    Science.gov (United States)

    Diaz, Jessica; Garbajosa, Juan; Calvo-Manzano, Jose A.

    CMMI has been adopted advantageously in large companies for improvements in software quality, budget fulfilling, and customer satisfaction. However SPI strategies based on CMMI-DEV require heavy software development processes and large investments in terms of cost and time that medium/small companies do not deal with. The so-called light software development processes, such as Agile Software Development (ASD), deal with these challenges. ASD welcomes changing requirements and stresses the importance of adaptive planning, simplicity and continuous delivery of valuable software by short time-framed iterations. ASD is becoming convenient in a more and more global, and changing software market. It would be greatly useful to be able to introduce agile methods such as Scrum in compliance with CMMI process model. This paper intends to increase the understanding of the relationship between ASD and CMMI-DEV reporting empirical results that confirm theoretical comparisons between ASD practices and CMMI level2.

  10. Mapping the functional connectome traits of levels of consciousness.

    Science.gov (United States)

    Amico, Enrico; Marinazzo, Daniele; Di Perri, Carol; Heine, Lizette; Annen, Jitka; Martial, Charlotte; Dzemidzic, Mario; Kirsch, Murielle; Bonhomme, Vincent; Laureys, Steven; Goñi, Joaquín

    2017-03-01

    Examining task-free functional connectivity (FC) in the human brain offers insights on how spontaneous integration and segregation of information relate to human cognition, and how this organization may be altered in different conditions, and neurological disorders. This is particularly relevant for patients in disorders of consciousness (DOC) following severe acquired brain damage and coma, one of the most devastating conditions in modern medical care. We present a novel data-driven methodology, connICA, which implements Independent Component Analysis (ICA) for the extraction of robust independent FC patterns (FC-traits) from a set of individual functional connectomes, without imposing any a priori data stratification into groups. We here apply connICA to investigate associations between network traits derived from task-free FC and cognitive/clinical features that define levels of consciousness. Three main independent FC-traits were identified and linked to consciousness-related clinical features. The first one represents the functional configuration of a "resting" human brain, and it is associated to a sedative (sevoflurane), the overall effect of the pathology and the level of arousal. The second FC-trait reflects the disconnection of the visual and sensory-motor connectivity patterns. It also relates to the time since the insult and to the ability of communicating with the external environment. The third FC-trait isolates the connectivity pattern encompassing the fronto-parietal and the default-mode network areas as well as the interaction between left and right hemispheres, which are also associated to the awareness of the self and its surroundings. Each FC-trait represents a distinct functional process with a role in the degradation of conscious states of functional brain networks, shedding further light on the functional sub-circuits that get disrupted in severe brain-damage. Copyright © 2017. Published by Elsevier Inc.

  11. Genome-wide nucleosome map and cytosine methylation levels of an ancient human genome

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Valen, Eivind; Velazquez, Amhed Missael Vargas;

    2014-01-01

    data generated from hair shafts of a 4000-yr-old Paleo-Eskimo belonging to the Saqqaq culture, we generate the first ancient nucleosome map coupled with a genome-wide survey of cytosine methylation levels. The validity of both nucleosome map and methylation levels were confirmed by the recovery...... of the expected signals at promoter regions, exon/intron boundaries, and CTCF sites. The top-scoring nucleosome calls revealed distinct DNA positioning biases, attesting to nucleotide-level accuracy. The ancient methylation levels exhibited high conservation over time, clustering closely with modern hair tissues...

  12. Ground-water protection, low-level waste, and below regulatory concern: What`s the connection?

    Energy Technology Data Exchange (ETDEWEB)

    Gruhlke, J.M.; Galpin, F.L. [Environmental Protection Agency, Washington, DC (United States). Office of Radiation Programs

    1991-12-31

    The Environmental Protection Agency (EPA) has a responsibility to protect ground water and drinking water under a wide variety of statutes. Each statute establishes different but specific requirements for EPA and applies to diverse environmental contaminants. Radionuclides are but one of the many contaminants subject to this regulatory matrix. Low-level radioactive waste (LLW) and below regulatory concern (BRC) are but two of many activities falling into this regulatory structure. The nation`s ground water serves as a major source of drinking water, supports sensitive ecosystems, and supplies the needs of agriculture and industry. Ground water can prove enormously expensive to clean up. EPA policy for protecting ground water has evolved considerably over the last ten years. The overall goal is to prevent adverse effects to human health, both now and in the future, and to protect the integrity of the nation`s ground-water resources. The Agency uses the Maximum Contaminant Levels (MCLs) under the Safe Drinking Water Act as reference points for protection in both prevention and remediation activities. What`s the connection? Both low-level waste management and disposal activities and the implementation of below regulatory concern related to low-level waste disposal have the potential for contaminating ground water. EPA is proposing to use the MCLs as reference points for low-level waste disposal and BRC disposal in order to define limits to the environmental contamination of ground water that is, or may be, used for drinking water.

  13. Magnification of label maps with a topology-preserving level-set method.

    Science.gov (United States)

    Trede, Dennis; Alexandrov, Theodore; Sagiv, Chen; Maass, Peter

    2012-09-01

    Image segmentation aims at partitioning an image into multiple segments. The application of this procedure produces a label map (also referred to as segmentation map) that classifies the pixels of the original image. In contrast to "natural" images, label maps are nominal-scale images, typically represented as integer-valued images. Nominal-scaled label maps can also appear as a representation of the raw data in areas, such as in geostatistics. In some applications, the original resolution of a label map does not suffice and a larger size map has to be generated. In this paper, we present a magnification algorithm for label maps and nominal images. The main property of our method is that it preserves the topology during the magnification process, which means that no isolated pixel vanishes. To the best of our knowledge, apart from nearest-neighbor interpolation, the problem of label map magnification has not previously been addressed in the literature. The main idea of the proposed method is to accomplish a boundary refinement by smoothing the regions' boundaries on a finer grid. The method relies on well known methods, namely, the fundamental operations of morphological image processing-erosion and dilation-and the level-set method. The level-set method is well suited for our purposes since it does not depend on a parametrization and it is numerically stable. The topological flexibility of the level-set method-often found to be an advantage in applications-is a drawback here, since the topology of the original label map should be preserved. However, using the so-called simple point criterion from digital topology, one can adapt the conventional level-set method so that the topology will not be modified throughout the magnification procedure.

  14. Database of groundwater levels and hydrograph descriptions for the Nevada Test Site area, Nye County, Nevada

    Science.gov (United States)

    Elliott, Peggy E.; Fenelon, Joseph M.

    2010-01-01

    A database containing water levels measured from wells in and near areas of underground nuclear testing at the Nevada Test Site was developed. The water-level measurements were collected from 1941 to 2016. The database provides information for each well including well construction, borehole lithology, units contributing water to the well, and general site remarks. Water-level information provided in the database includes measurement source, status, method, accuracy, and specific water-level remarks. Additionally, the database provides hydrograph narratives that document the water-level history and describe and interpret the water-level hydrograph for each well.Water levels in the database were quality assured and analyzed. Multiple conditions were assigned to each water-level measurement to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed to each water-level measurement.

  15. Hydrologic conditions in urban Miami-Dade County, Florida, and the effect of groundwater pumpage and increased sea level on canal leakage and regional groundwater flow

    Science.gov (United States)

    Hughes, Joseph D.; White, Jeremy T.

    2014-01-01

    The extensive and highly managed surface-water system in southeastern Florida constructed during the 20th Century has allowed for the westward expansion of urban and agricultural activities in Miami-Dade County. In urban areas of the county, the surface-water system is used to (1) control urban flooding, (2) supply recharge to production well fields, and (3) control seawater intrusion. Previous studies in Miami-Dade County have determined that on a local scale, leakage from canals adjacent to well fields can supply a large percentage (46 to 78 percent) of the total groundwater pumpage from production well fields. Canals in the urban areas also receive seepage from the Biscayne aquifer that is derived from a combination of local rainfall and groundwater flow from Water Conservation Area 3 and Everglades National Park, which are west of urban areas of Miami-Dade County.

  16. Changes in groundwater levels and the response of natural vegetation to transfer of water to the lower reaches of the Tarim River

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Restoration and reconstruction of the degraded Tarim River ecosystem is an important challenge. A goal of an ecological water conveyance project is to protect and restore the natural vegetation in the lower reaches of Tarim River by transferring water from Bosten Lake, through the river channel, to the lower reaches. This study describes the changes in groundwater depth during the water transfer and the respondence of riparian vegetation to alterations in groundwater levels. The results indicate that groundwater depth along the Tarim River channel has a significant spatial-temporal component. Groundwater levels closest to the river channel show the most immediate and pronounced changes as a response to water transfer while those further away respond more slowly, although the observed change appears to be longer in duration. With a rise in the groundwater level, natural vegetation responded with higher growth rates, biomass and biodiversity. These favorable changes show that it is feasible to protect and restore the degraded natural vegetation by raising the groundwater depth. Plant communities are likely to reflect the hysteresis phenomenon, requiring higher water levels to initiate and stimulate desired growth than what may be needed to maintain the plant community. Because different species have different ecologies, including different root depths and densities and water needs, their response to increasing water availability will be spatially and temporally heterogenous. The response of vegetation is also influenced by microtopography and watering style. This paper discusses strategies for the protection and restoration of the degraded vegetation in the lower reaches of the Tarim River and provides information to complement ongoing theoretical research into ecological restoration in arid or semi-arid ecosystems.

  17. Leveling data in geochemical mapping: scope of application, pros and cons of existing methods

    Science.gov (United States)

    Pereira, Benoît; Vandeuren, Aubry; Sonnet, Philippe

    2017-04-01

    Geochemical mapping successfully met a range of needs from mineral exploration to environmental management. In Europe and around the world numerous geochemical datasets already exist. These datasets may originate from geochemical mapping projects or from the collection of sample analyses requested by environmental protection regulatory bodies. Combining datasets can be highly beneficial for establishing geochemical maps with increased resolution and/or coverage area. However this practice requires assessing the equivalence between datasets and, if needed, applying data leveling to remove possible biases between datasets. In the literature, several procedures for assessing dataset equivalence and leveling data are proposed. Daneshfar & Cameron (1998) proposed a method for the leveling of two adjacent datasets while Pereira et al. (2016) proposed two methods for the leveling of datasets that contain records located within the same geographical area. Each discussed method requires its own set of assumptions (underlying populations of data, spatial distribution of data, etc.). Here we propose to discuss the scope of application, pros, cons and practical recommendations for each method. This work is illustrated with several case studies in Wallonia (Southern Belgium) and in Europe involving trace element geochemical datasets. References: Daneshfar, B. & Cameron, E. (1998), Leveling geochemical data between map sheets, Journal of Geochemical Exploration 63(3), 189-201. Pereira, B.; Vandeuren, A.; Govaerts, B. B. & Sonnet, P. (2016), Assessing dataset equivalence and leveling data in geochemical mapping, Journal of Geochemical Exploration 168, 36-48.

  18. Analyzing Classroom Strategy: Evaluating the Concept Mapping Technique at SSC Level in Pakistan

    Directory of Open Access Journals (Sweden)

    Sidra Mahmood

    2015-08-01

    Full Text Available This study documents the usage of Concept Mapping in the teaching-learning situation of English at SSC Level. The study is descriptive and analytical in nature and tries to investigate the effects which Concept Mapping renders in the academic environment in the context of ESL classroom setting. The research offers strategies for adopting certain techniques and up gradation of the content taught at the mentioned level by the inculcation of such techniques. Overall, the study produced a range of implementable outcomes by a pervasive discussion of Concept Mapping, the role of the textbooks, the importance of adding the technique to the contents of ESL classroom setting. For data collection and data analysis, two classes were selected. Both were taught the same content under controlled conditions. The concept mapping technique in the class guided the learners towards the improved way of learning the text of second language.

  19. Zr and U determination at trace level in simulated deep groundwater by Q ICP-MS using extraction chromatography.

    Science.gov (United States)

    Gautier, C; Coppo, M; Caussignac, C; Laszak, I; Fichet, P; Goutelard, F

    2013-03-15

    In the framework of trace element analysis by Q ICP-MS in a simulated deep Callovo-Oxfordian groundwater, separation procedures based on extraction chromatography were developed to eliminate the high salt contents and to concentrate Zr and U simultaneously. Theoretical and experimental speciation studies showed the importance of adjusting the medium to HNO₃/HF (0.5 M/0.005 M) to guarantee the stability over time of the analytes before removal of the matrix. Two preconcentration methods based on TRU and TODGA resins were optimized for the simultaneous isolation of Zr and U prior to Q ICP-MS measurements. Using TRU resin, alkali and alkali earth metals contained in the deep groundwater were removed with 2 M HNO₃ whereas Zr and U were recovered with a HNO₃/NH₄HC₂O₄ (0.02 M/0.05 M) medium. For the separation protocol based on TODGA resin, alkali and alkali earth metals were eliminated with 3 M and 11 M HNO₃ while Zr and U were simultaneously stripped with a HNO₃/HF (0.5 M/0.2 M) medium. The procedure optimized on TODGA resin was validated with the French AFNOR NF T90-210 standard by studying linearity, limits of quantification (LOQ) and separation yields. The LOQ was determined at 0.008 μg L(-1) for Zr and U after the separation. Both analytes were recovered quantitatively. Compared to a sample dilution implemented to reduce the matrix effects, the developed preconcentration method allowed improving the sensitivity up to a 20 fold factor for Zr and U measurements at trace level by Q ICP-MS. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Underwater Source-Level Estimation using Sparsity-Cognizant Source-Location Mapping

    Science.gov (United States)

    2014-12-01

    shallow water is characterized by multipath due to the multiple interactions that they sustain with the sea surface and sea floor , by refraction due to a...TECHNICAL REPORT 2060 ember 2014 Underwater Source-Level Estimation using Sparsity-Cognizant Source-Location Mapping ...to localize the target, which is accomplished by using the Sparsity-Cognizant Source Location Mapping (scSLM) algorithm, developed at the Space and

  1. Regulation by gravity of the transcript levels of MAP65 in azuki bean epicotyls

    Science.gov (United States)

    Soga, Kouichi; Hoson, Takayuki; Wakabayashi, Kazuyuki; Kotake, Toshihisa

    2012-07-01

    Development of a short and thick body by reorientation of cortical microtubules is required for the resistance of plants to the gravitational force. The 65 kDa microtubule-associated protein (MAP65) has microtubule bundling activity and is involved in the reorientation of cortical microtubules. Here, we investigated the relation between the orientation of cortical microtubules and the transcript levels of VaMAP65-1 under centrifugal hypergravity conditions in azuki bean epicotyls. The percentage of cells with transverse microtubules was decreased, while that with longitudinal microtubules was increased, in proportion to the logarithm of the magnitude of gravity. The orientation of microtubules was restored to the original direction after removal of the hypergravity stimulus. The transcript level of VaMAP65-1 was down-regulated in proportion to the logarithm of the magnitude of gravity (R=-0.99). By removal of hypergravity stimulus, expression of VaMAP65-1 was increased to control levels. Strong correlations were observed between the percentage of cells with longitudinal or transverse microtubules and the transcript levels of VaMAP65-1 (R=-0.93, 0.91). These results suggest that down-regulation of VaMAP65-1 expression is involved in the regulation by gravity of the orientation of cortical microtubules in azuki bean epicotyls. Lanthanum and gadolinium ions, potential blockers of mechanosensitive calcium ion-permeable channels (mechanoreceptors), nullified the down-regulation of expression of VaMAP65-1 gene, suggesting that mechanoreceptors are responsible for regulation by gravity of VaMAP65-1 expression.

  2. Marine water from mid-Holocene sea level highstand trapped in a coastal aquifer: Evidence from groundwater isotopes, and environmental significance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Stephen [School of Civil, Environmental and Chemical Engineering, RMIT University, Melbourne (Australia); Currell, Matthew, E-mail: Matthew.currell@rmit.edu.au [School of Civil, Environmental and Chemical Engineering, RMIT University, Melbourne (Australia); Cendón, Dioni I. [Australian Nuclear Science and Technology Organisation, Kirrawee (Australia); Connected Water Initiative, School of Biological, Earth and Environmental Sciences, University of New South Wales (UNSW), Sydney (Australia)

    2016-02-15

    A multi-layered coastal aquifer in southeast Australia was assessed using environmental isotopes, to identify the origins of salinity and its links to palaeo-environmental setting. Spatial distribution of groundwater salinity (electrical conductivity values ranging from 0.395 to 56.1 mS/cm) was examined along the coastline along with geological, isotopic and chemical data. This allowed assessment of different salinity sources and emplacement mechanisms. Molar chloride/bromide ratios range from 619 to 1070 (621 to 705 in samples with EC > 15 mS/cm), indicating salts are predominantly marine. Two distinct vertical salinity profiles were observed, one with increasing salinity with depth and another with saline shallow water overlying fresh groundwater. The saline shallow groundwater (EC = 45.4 to 55.7 mS/cm) has somewhat marine-like stable isotope ratios (δ{sup 18}O = − 2.4 to − 1.9 ‰) and radiocarbon activities indicative of middle Holocene emplacement (47.4 to 60.4 pMC). This overlies fresher groundwater with late Pleistocene radiocarbon ages and meteoric stable isotopes (δ{sup 18}O = − 5.5 to − 4.6‰). The configuration suggests surface inundation of the upper sediments by marine water during the mid-Holocene (c. 2–8 kyr BP), when sea level was 1–2 m above today's level. Profiles of chloride, stable isotopes, and radiocarbon indicate mixing between this pre-modern marine water and fresh meteoric groundwater to varying degrees around the coastline. Mixing calculations using chloride and stable isotopes show that in addition to fresh-marine water mixing, some salinity is derived from transpiration by halophytic vegetation (e.g. mangroves). The δ{sup 13}C ratios in saline water (− 17.6 to − 18.4‰) also have vegetation/organic matter signatures, consistent with emplacement by surface inundation and extensive interaction between vegetation and recharging groundwater. Saline shallow groundwater is preserved only in areas where low

  3. Using airborne geophysical surveys to improve groundwater resource management models

    Science.gov (United States)

    Abraham, Jared D.; Cannia, James C.; Peterson, Steven M.; Smith, Bruce D.; Minsley, Burke J.; Bedrosian, Paul A.

    2010-01-01

    Increasingly, groundwater management requires more accurate hydrogeologic frameworks for groundwater models. These complex issues have created the demand for innovative approaches to data collection. In complicated terrains, groundwater modelers benefit from continuous high‐resolution geologic maps and their related hydrogeologic‐parameter estimates. The USGS and its partners have collaborated to use airborne geophysical surveys for near‐continuous coverage of areas of the North Platte River valley in western Nebraska. The survey objectives were to map the aquifers and bedrock topography of the area to help improve the understanding of groundwater‐surface‐water relationships, leading to improved water management decisions. Frequency‐domain heliborne electromagnetic surveys were completed, using a unique survey design to collect resistivity data that can be related to lithologic information to refine groundwater model inputs. To render the geophysical data useful to multidimensional groundwater models, numerical inversion is necessary to convert the measured data into a depth‐dependent subsurface resistivity model. This inverted model, in conjunction with sensitivity analysis, geological ground truth (boreholes and surface geology maps), and geological interpretation, is used to characterize hydrogeologic features. Interpreted two‐ and three‐dimensional data coverage provides the groundwater modeler with a high‐resolution hydrogeologic framework and a quantitative estimate of framework uncertainty. This method of creating hydrogeologic frameworks improved the understanding of flow path orientation by redefining the location of the paleochannels and associated bedrock highs. The improved models reflect actual hydrogeology at a level of accuracy not achievable using previous data sets.

  4. Simulation of the regional groundwater-flow system of the Menominee Indian Reservation, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Dunning, Charles P.

    2015-01-01

    A regional, two-dimensional, steady-state groundwater-flow model was developed to simulate the groundwater-flow system and groundwater/surface-water interactions within the Menominee Indian Reservation. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Menominee Indian Tribe of Wisconsin, to contribute to the fundamental understanding of the region’s hydrogeology. The objectives of the regional model were to improve understanding of the groundwater-flow system, including groundwater/surface-water interactions, and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate groundwater/surface-water interactions, provide a framework for simulating regional groundwater-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate groundwater-flow patterns at multiple scales. Simulations made with the regional model reproduce groundwater levels and stream base flows representative of recent conditions (1970–2013) and illustrate groundwater-flow patterns with maps of (1) the simulated water table and groundwater-flow directions, (2) probabilistic areas contributing recharge to high-capacity pumped wells, and (3) estimation of the extent of infiltrated wastewater from treatment lagoons.

  5. Elevated levels of iron in groundwater in Prey Veng province in Cambodia: a possible factor contributing to high iron stores in women.

    Science.gov (United States)

    Karakochuk, Crystal D; Murphy, Heather M; Whitfield, Kyly C; Barr, Susan I; Vercauteren, Suzanne M; Talukder, Aminuzzaman; Porter, Keith; Kroeun, Hou; Eath, Many; McLean, Judy; Green, Timothy J

    2015-06-01

    Iron is a natural element found in food, water and soil and is essential for human health. Our aim was to determine the levels of iron and 25 other metals and trace elements in groundwater from 22 households in Prey Veng, Cambodia. Water analyses were conducted using inductively coupled plasma-mass spectrometry and optical emission spectrometry. Compared to the 2011 World Health Organization guidelines for drinking water quality, aluminum, iron and manganese exceeded maximum levels (in 4.5, 72.7 and 40.9% of samples, respectively). Compared to the 2004 Cambodian drinking water quality standards, iron and manganese exceeded maximum levels (in 59.1 and 36.4% of samples, respectively). We found no evidence of arsenic contamination. Guidelines for iron were established primarily for esthetic reasons (e.g. taste), whereas other metals and elements have adverse effects associated with toxicity. Iron in groundwater ranged from 134 to 5,200 μg/L (mean ∼1,422 μg/L). Based on a daily consumption of 3 L groundwater, this equates to ∼0.4-15.6 mg iron (mean ∼4.3 mg/day), which may be contributing to high iron stores and the low prevalence of iron deficiency anemia in Prey Veng women. Elevated levels of manganese in groundwater are a concern and warrant further investigation.

  6. Regional scale analysis of landform configuration with base-level (isobase maps

    Directory of Open Access Journals (Sweden)

    C. H. Grohmann

    2011-05-01

    Full Text Available Base-level maps (or "isobase maps", as originally defined by Filosofov, 1960, express a relationship between valley order and topography. The base-level map can be seen as a "simplified" version of the original topographic surface, from which the "noise" of the low-order stream erosion was removed. This method is able to identify areas with possible tectonic influence even within lithologically uniform domains. Base-level maps have been recently applied in semi-detail scale (e.g., 1:50 000 or larger morphotectonic analysis. In this paper, we present an evaluation of the method's applicability in regional-scale analysis (e.g., 1:250 000 or smaller. A test area was selected in northern Brazil, at the lower course of the Araguaia and Tocantins rivers. The drainage network extracted from SRTM30_PLUS DEMs with spatial resolution of approximately 900 m was visually compared with available topographic maps and considered to be compatible with a 1:1,000 000 scale. Regarding the interpretation of regional-scale morphostructures, the map constructed with 2nd and 3rd-order valleys was considered to present the best results. Some of the interpreted base-level anomalies correspond to important shear zones and geological contacts present in the 1:5 000 000 Geological Map of South America. Others have no correspondence with mapped Precambrian structures and are considered to represent younger, probably neotectonic, features. A strong E-W orientation of the base-level lines over the inflexion of the Araguaia and Tocantins rivers, suggest a major drainage capture. A N-S topographic swath profile over the Tocantins and Araguaia rivers reveals a topographic pattern which, allied with seismic data showing a roughly N-S direction of extension in the area, lead us to interpret this lineament as an E-W, southward-dipping normal fault. There is also a good visual correspondence between the base-level lineaments and geophysical anomalies. A NW-SE lineament in the

  7. Limits to global groundwater consumption

    Science.gov (United States)

    de Graaf, I.; Van Beek, L. P.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

    2016-12-01

    Groundwater is the largest accessible freshwater resource worldwide and is of critical importance for irrigation, and so for global food security. For many regions of the world where groundwater abstraction exceeds groundwater recharge, persistent groundwater depletion occurs. A direct consequence of depletion is falling groundwater levels, reducing baseflows to rivers, harming ecosystems. Also, pumping costs increase, wells dry up and land subsidence can occur. Water demands are expected to increase further due to growing population, economic development and climate change, posing the urgent question how sustainable current water abstractions are worldwide and where and when these abstractions approach conceivable limits with all the associated problems. Here, we estimated past and future trends (1960-2050) in groundwater levels resulting from changes in abstractions and climate and predicted when limits of groundwater consumption are reached. We explored these limits by predicting where and when groundwater levels drop that low that groundwater becomes unattainable for abstractions and how river flows are affected. Water availabilities, abstractions, and lateral groundwater flows are simulated (5 arcmin. resolution) using a coupled version of the global hydrological model PCR-GLOBWB and a groundwater model based on MODFLOW. The groundwater model includes a parameterization of the worlds confined and unconfined aquifer systems, needed for a realistic simulation of groundwater head dynamics. Results show that, next to the existing regions experiencing groundwater depletion (like India, Pakistan, Central Valley) new regions will develop, e.g. Southern Europe, the Middle East, and Africa. Using a limit that reflects present-day feasibility of groundwater abstraction, we estimate that in 2050 groundwater becomes unattainable for 20% of the global population, mainly in the developing countries and pumping cost will increase significantly. Largest impacts are found

  8. A Holistic Assessment of the Sustainability of Groundwater Resources in the North China Plain

    Science.gov (United States)

    Cao, G.; Zheng, C.; Liu, J.; Li, W.

    2010-12-01

    The North China Plain (NCP) is one of the most important agricultural and economic regions of China and also one of the most densely populated in the world (~ 900 people/km2). In recent years, groundwater provides ~ 70% of the total water supply to support grain production, rapid economic development and population growth. Analysis of historical groundwater level contour maps and more than 230 monitoring well time series across the NCP shows a general long-term trend of depletion in groundwater storage in both shallow unconfined and deep confined aquifer zones. Groundwater depletion in the NCP has adversely affected the environment and ecosystems, including drying-up of rivers, land subsidence, seawater intrusion, and groundwater quality deterioration. The volume of groundwater depleted from the aquifer has been estimated from groundwater level fluctuation data by directly integrating the groundwater level change and specific yield across the NCP. The estimated amount of annual groundwater storage change based on this method is ~4 billion m3. A numerical groundwater flow model has been developed for the entire Quaternary aquifer of the NCP and is reasonably well calibrated for both the predevelopment period (1960s) and post-development conditions over the past 40 years. The output of the groundwater model provides estimates of groundwater depletion rates over the post-development period, and the model-calculated storage variation is consistent with the amount determined from groundwater level fluctuation data independent of the model. Moreover, the mean annual total recharge calibrated through the groundwater model is ~120 mm, which is in reasonable agreement with previously reported values based on the water balance method. The groundwater storage depletion derived either from the groundwater level fluctuation data or from the numerical simulation model is highly correlated with spatially averaged precipitation. The model simulations indicate that a decrease in

  9. Application and evaluation of universal kriging for optimal contouring of groundwater levels

    Indian Academy of Sciences (India)

    B V N P Kambhammettu; Praveena Allena; James P King

    2011-06-01

    This paper deals with the application of universal kriging to interpolate water table elevations from their measurements at random locations. Geographic information system tools were used to generate the continuous surface of water table elevations for the Carlsbad area alluvial aquifer located to the southeast of New Mexico, USA.Water table elevations in the 38 monitoring wells that are common to 1996 and 2003 irrigation years follows normal distribution. A generalized MATLAB^® code was developed to generate omni-directional and directional semi-variograms (at 22.5° intervals). Low-order polynomials were used to model the trend as the water table profile exhibits a south-east gradient. Different theoretical semivariogram models were tried to select the base semi-variogram for performing geostatistical interpolation. The contour maps of water table elevations exhibit significant decrease in the water table from 1996 to 2003. Statistical analysis performed on the estimated contours revealed that the decrease in water table is between 0.6 and 4.5 m at 90% confidence. The estimation variance contours show that the error in estimation was more than 8m2 in the west and south-west portions of the aquifer due to the absence of monitoring wells.

  10. Ground-water discharge determined from measurements of evapotranspiration, other available hydrologic components, and shallow water-level changes, Oasis Valley, Nye County, Nevada

    Science.gov (United States)

    Reiner, S.R.; Laczniak, R.J.; DeMeo, G.A.; Smith, Jody L.; Elliott, P.E.; Nylund, W.E.; Fridrich, C.J.

    2002-01-01

    component of 0.5 foot, is estimated to be about 6,000 acre-feet. Annual subsurface outflow from Oasis Valley into the Amargosa Desert is estimated to be between 30 and 130 acre-feet. Estimates of total annual ground-water withdrawal from Oasis Valley by municipal and non-municipal users in 1996 and 1999 are 440 acre-feet and 210 acre-feet, respectively. Based on these values, natural annual ground-water discharge from Oasis Valley is about 6,100 acre-feet. Total annual discharge was 6,500 acre-ft in 1996 and 6,300 acre-ft in 1999. This quantity of natural ground-water discharge from Oasis Valley exceeds the previous estimate made in 1962 by a factor of about 2.5. Water levels were measured in Oasis Valley to gain additional insight into the ET process. In shallow wells, water levels showed annual fluctuations as large as 7 feet and daily fluctuations as large as 0.2 foot. These fluctuations may be attributed to water loss associated with evapotranspiration. In shallow wells affected by ET, annual minimum depths to water generally occurred in winter or early spring shortly after daily ET reached minimum rates. Annual maximum depths to water generally occurred in late summer or fall shortly after daily ET reached maximum rates. The magnitude of daily water-level fluctuations generally increased as ET increased and decreased as depth to water increased.

  11. Selection of a taxonomic level for soil mapping using diversity and map purity indices: A case study from an Iranian arid region

    Science.gov (United States)

    Jafari, A.; Ayoubi, S.; Khademi, H.; Finke, P. A.; Toomanian, N.

    2013-11-01

    There is a growing demand for digital soil maps for environmental planning, modeling and management. If mapped soil classes are taken from a hierarchical taxonomic system, a question arises: which taxonomic level is most appropriate to be depicted on the map with a given sample size, available environmental covariates and the strength of predictive relations between covariates and the soil classes? Pedodiversity, the study and measurement of soil diversity, can be considered as a framework to analyze spatial patterns depicted on soil maps. This paper discusses the selection of the taxonomic level for soil mapping in an arid region in southeast Iran on the basis of (1) the purity of a digital soil class map derived from an artificial neural network (ANN) prediction method using environmental covariates and (2) pedodiversity indices of these soil maps. The prediction of soil classes and the calculation of diversity indices were carried out for taxonomic categories of order, suborder, great group, and subgroup. Using the feed forward back-propagation algorithm, three-layer ANNs with input, hidden and output layers were trained for soil class prediction at each category level. In most predictions, the combined use of terrain attributes and geomorphic surfaces provided the best results. When the taxonomic level changed from order to subgroup, the purity decreased, whereas the values of the diversity indices increased. The highest purity and lowest diversity are observed at the order level, indicating a good quality map in terms of its purity, but reflecting only little soil diversity, thus with a low usage potential. On the other hand, soil maps at the level of subgroup illustrate high diversity and low purity, so that the predicted map units are highly uncertain. This map is also inappropriate for users. We introduced an index combining the diversity and purity which indicated that the best taxonomic level for soil mapping in the study area is the great group, with

  12. Providing Source Code Level Portability Between CPU and GPU with MapCG

    Institute of Scientific and Technical Information of China (English)

    Chun-Tao Hong; De-Hao Chen; Yu-Bei Chen; Wen-Guang Chen; Wei-Min Zheng; Hai-Bo Lin

    2012-01-01

    Graphics processing units (GPU) have taken an important role in the general purpose computing market in recent years.At present,the common approach to programming GPU units is to write GPU specific code with low level GPU APIs such as CUDA.Although this approach can achieve good performance,it creates serious portability issues as programmers are required to write a specific version of the code for each potential target architecture.This results in high development and maintenance costs.We believe it is desirable to have a programming model which provides source code portability between CPUs and GPUs,as well as different GPUs.This would allow programmers to write one version of the code,which can be compiled and executed on either CPUs or GPUs efficiently without modification.In this paper,we propose MapCG,a MapReduce framework to provide source code level portability between CPUs and GPUs.In contrast to other approaches such as OpenCL,our framework,based on MapReduce,provides a high level programming model and makes programming much easier.We describe the design of MapCG,including the MapReduce-style high-level programming framework and the runtime system on the CPU and GPU.A prototype of the MapCG runtime,supporting multi-core CPUs and NVIDIA GPUs,was implemented. Our experimental results show that this implementation can execute the same source code efficiently on multi-core CPU platforms and GPUs,achieving an average speedup of 1.6~2.5x over previous implementations of MapReduce on eight commonly used applications.

  13. Linking Organic Matter Deposition And Iron Mineral Transformations to Groundwater Arsenic Levels in the Mekong Delta, Cambodia

    Energy Technology Data Exchange (ETDEWEB)

    Quicksall, A.N.; Bostick, B.C.; Sampson, M.L.

    2009-05-21

    Enriched As in drinking water wells in south and Southeast Asia has increased the risk of cancer for nearly 100 million people. This enrichment is generally attributed to the reductive dissolution of Fe oxides; however, the complex expression of As enrichment in these areas is not yet well understood. Here, the coupled sedimentological and geochemical factors that contribute to the extent and spatial distribution of groundwater As concentrations in the Mekong River delta, Cambodia in an avulsed scroll bar sequence are examined. X-Ray absorption spectroscopy (XAS) was used to determine Fe and As speciation in redox preserved sediment collected from drilled cores. Dissolved As, Fe and S solution concentrations in existing and newly drilled wells (cores) differed considerably depending on their source sedimentology. The rapid burial of organic matter in the scroll bar sequence facilitated the development of extensive Fe-reducing conditions, and As release into the aquifer. In older features organic C levels are high enough to sustain extensive Fe reduction and provide ample SO{sub 4} which is reduced to sulfide. This S reduction impacts As levels; As is sequestered in sulfide minerals outside of the scrollbar sequence, decreasing pore water concentrations. In contrast, As is depleted in sediments from the scroll sequence, and associated with elevated pore water aqueous concentrations. The concentration and form of organic C in the scrollbar sequence is related to depositional environment, and can facilitate Fe and S mineral transformations, distinct sedimentary environments explain a portion of the inherent heterogeneity of aquifer As concentrations.

  14. Geological and geomorphological controls on groundwater occurrence in a hard rock region

    Science.gov (United States)

    Rajaveni, S. P.; Brindha, K.; Elango, L.

    2017-06-01

    Remote sensing and GIS tools have broadly helped hydrogeologists to delineate the groundwater prospective zones for watershed development and management. The origin, movement and existence of groundwater depends on several factors such as slope, drainage density, land use, geology, lineament density and geomorphology. Based on these, the mapping and identification of groundwater potential zones were carried out in a part of Nalgonda district, Telangana, India. The regions were categorised as high, moderate and low groundwater potential, and they were validated with the groundwater levels and yield of wells located in the corresponding zones. Extensive possibility for watershed development is possible in 41 % of the total 724 km2 and 46 % of the area offers moderate options. Any groundwater management project implemented in these favourable areas will bring maximum benefit. Similar studies should be considered necessary before designing a water resource development activity as it will reduce the cost on detailed field visits which are time-consuming.

  15. Analysis of groundwater anomalies using GRACE over various districts of Jharkhand

    Science.gov (United States)

    Verma, Arpita; Kumar, Anant; Kumar, Sanjay

    2016-05-01

    Groundwater is an important requirement for the massive population of India. Generally the groundwater level is monitored by using monitoring wells. In this study, Gravity Recovery and Climate Experiment (GRACE) Terrestrial Water Storage (TWS), Land surface state variable GLDAS and Soil Moisture (SM) data were tested for estimating ground water information and based on these groundwater assessments were carried out over the years 2003 to 2012 for Jharkhand State. Additionally, Tropical Rainfall Measuring Mission (TRMM) accumulated rainfall data was also used for the year's 2008 to 2012.From the study over 120 months span of various districts the maximum depletion in storage of groundwater averaged over the six districts is +/-5cm/yr in the year 2010 and maximum storage year (in term of Equivalent water thickness) groundwater average over the six districts is +/-4.4cm in the year 2003. The study also utilized ground based Seasonal changes in the groundwater resource over 287 monitoring wells and estimated groundwater data using map analysis over Jharkhand. This study analyzed seasonal water level variations based on groundwater anomaly. Remote sensing generated result compared with well data shows R2 = 0.6211 and RMSE = 39.46 cm at average seasonal cycle. Also information of different time periods of rainfall (i.e., pre-monsoon and post-monsoon) was analyzed. The trend analysis of rainfall and estimated groundwater gives the basic knowledge that groundwater storage loss and gain showed similarities with increase and decrease in rainfall.

  16. Nitrate contamination risk assessment in groundwater at regional scale

    Science.gov (United States)

    Daniela, Ducci

    2016-04-01

    Nitrate groundwater contamination is widespread in the world, due to the intensive use of fertilizers, to the leaking from the sewage network and to the presence of old septic systems. This research presents a methodology for groundwater contamination risk assessment using thematic maps derived mainly from the land-use map and from statistical data available at the national institutes of statistic (especially demographic and environmental data). The potential nitrate contamination is considered as deriving from three sources: agricultural, urban and periurban. The first one is related to the use of fertilizers. For this reason the land-use map is re-classified on the basis of the crop requirements in terms of fertilizers. The urban source is the possibility of leaks from the sewage network and, consequently, is linked to the anthropogenic pressure, expressed by the population density, weighted on the basis of the mapped urbanized areas of the municipality. The periurban sources include the un-sewered areas, especially present in the periurban context, where illegal sewage connections coexist with on-site sewage disposal (cesspools, septic tanks and pit latrines). The potential nitrate contamination map is produced by overlaying the agricultural, urban and periurban maps. The map combination process is very easy, being an algebraic combination: the output values are the arithmetic average of the input values. The groundwater vulnerability to contamination can be assessed using parametric methods, like DRASTIC or easier, like AVI (that involves a limited numbers of parameters). In most of cases, previous documents produced at regional level can be used. The pollution risk map is obtained by combining the thematic maps of the potential nitrate contamination map and the groundwater contamination vulnerability map. The criterion for the linkages of the different GIS layers is very easy, corresponding to an algebraic combination. The methodology has been successfully

  17. Natural background levels and threshold values of chemical species in three large-scale groundwater bodies in Northern Italy

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, Antonio, E-mail: ant.molinari2002@libero.it [Politecnico di Milano, Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture Viarie e Rilevamento, Piazza L. Da Vinci, 32-20133 Milano (Italy); Guadagnini, Laura [Politecnico di Milano, Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture Viarie e Rilevamento, Piazza L. Da Vinci, 32-20133 Milano (Italy); Marcaccio, Marco [ARPA Emilia-Romagna, Direzione Tecnica, Largo Caduti del Lavoro, 6-40122 Bologna (Italy); Guadagnini, Alberto [Politecnico di Milano, Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture Viarie e Rilevamento, Piazza L. Da Vinci, 32-20133 Milano (Italy)

    2012-05-15

    We analyze natural background levels (NBLs) and threshold values (TVs) of spatially distributed chemical species (NH{sub 4}, B and As) which may be a potential pressure and concern in three large scale alluvial and fluvio-deltaic aquifers at different depths of the Apennines and Po river plains in Emilia-Romagna, Northern Italy. Our results are based on statistical methodologies designed to separate the natural and anthropogenic contributions in monitored concentrations by modeling the empirical distribution of the detected concentration with a mixture of probability density functions. Available chemical observations are taken over a 20 years period and are associated with different depths and cover planar investigation scales of the order of hundreds of kilometers. High concentration values detected for NH{sub 4} and B appear to be related to high natural background levels. Due to interaction with the host rock in different geochemical environments we observed that concentration vary in time and space (including in depth) consistently with the hydrogeochemical features and the occurrence of natural attenuation mechanisms in the analyzed reservoirs. Conversely, estimated As NBLs are not consistent with the conceptual model of the hydrogeochemical behavior of the systems analyzed and experimental evidences of As content in aquifer cores. This is due to the inability of these techniques to incorporate the complex dynamics of the processes associated with the specific hydrogeochemical setting. Statistical analyses performed upon aggregating the concentration data according to different time observation windows allow identifying temporal dynamics of NBLs and TVs of target compounds within the observation time frame. Our results highlight the benefit of a dynamic monitoring process and analysis of well demarcated groundwater bodies to update the associated NBLs as a function of the temporal dependence of natural processes occurring in the subsurface. Monitoring

  18. Water level observations from Unmanned Aerial Vehicles for improving estimates of surface water-groundwater interaction

    DEFF Research Database (Denmark)

    Bandini, Filippo; Butts, Michael; Vammen Jacobsen, Torsten

    2017-01-01

    . However, traditional river gauging stations are normally spaced too far apart to capture spatial patterns in the water surface, while spaceborne observations have limited spatial and temporal resolution. UAVs (Unmanned Aerial Vehicles) can retrieve river water level measurements, providing: i) high...

  19. Joint Assimilation of InSAR and Water-level Data for Aquifer Parameter Estimation and Groundwater State Forecasting in Santa Clara Valley, California

    Science.gov (United States)

    Abdullin, Ayrat; Jonsson, Sigurjon

    2017-04-01

    Ground subsidence induced by groundwater withdrawal is a widespread problem and can cause damage to buildings and infrastructure. The challenge is to forecast, accurately and in a cost effective way, when water extraction may threaten infrastructure, so that procedures can be applied to avoid unacceptable levels of ground deformation beyond construction engineering criteria. However, many characteristics of the heterogeneity of aquifer parameters, such as hydraulic conductivity and storage coefficients, are usually uncertain. Monitoring data, such as water-level data in monitoring wells, can be used to reduce these uncertainties, but the difficulty is that they usually only provide spatially limited information about the groundwater system. To take on these problems, we use an ensemble-based assimilation framework that efficiently integrates InSAR-derived displacements and hydraulic head data for improved understanding of groundwater reservoir behavior. We apply this framework for aquifer parameter estimation of the basin-wide Santa Clara Valley groundwater system in northern California. To study the deformation patterns in the area, we use time-series analysis of InSAR data, based on more than 150 images from the ERS, Envisat and ALOS satellites from 1992-2012. Using the InSAR observations, in addition to approximate data on pumping, managed recharge and rainfall amounts, we are able to advance our understanding of the ongoing hydrogeological processes within the aquifer system. We find that including both InSAR and well water-level data as observations improves the properties estimation compared to basic statistical interpolation between the available well data. We also compare the performance of our hydraulic head predictions with previous groundwater studies in Santa Clara Valley, such as those of Chaussard et al. (2014). The results suggest that the high spatial resolution subsidence observations from InSAR are useful for accurately quantifying hydraulic

  20. Development and application of a novel method for regional assessment of groundwater contamination risk in the Songhua River Basin.

    Science.gov (United States)

    Nixdorf, Erik; Sun, Yuanyuan; Lin, Mao; Kolditz, Olaf

    2017-12-15

    The main objective of this study is to quantify the groundwater contamination risk of Songhua River Basin by applying a novel approach of integrating public datasets, web services and numerical modelling techniques. To our knowledge, this study is the first to establish groundwater risk maps for the entire Songhua River Basin, one of the largest and most contamination-endangered river basins in China. Index-based groundwater risk maps were created with GIS tools at a spatial resolution of 30arc sec by combining the results of groundwater vulnerability and hazard assessment. Groundwater vulnerability was evaluated using the DRASTIC index method based on public datasets at the highest available resolution in combination with numerical groundwater modelling. As a novel approach to overcome data scarcity at large scales, a web mapping service based data query was applied to obtain an inventory for potential hazardous sites within the basin. The groundwater risk assessment demonstrated that contamination risk. These areas were mainly located in the vast plain areas with hotspots particularly in the Changchun metropolitan area. Moreover, groundwater levels and pollution point sources were found to play a significantly larger impact in assessing these areas than originally assumed by the index scheme. Moderate contamination risk was assigned to 27% of the aquifers, predominantly associated with less densely populated agricultural areas. However, the majority of aquifer area in the sparsely populated mountain ranges displayed low groundwater contamination risk. Sensitivity analysis demonstrated that this novel method is valid for regional assessments of groundwater contamination risk. Despite limitations in resolution and input data consistency, the obtained groundwater contamination risk maps will be beneficial for regional and local decision-making processes with regard to groundwater protection measures, particularly if other data availability is limited. Copyright

  1. Culture, climate change and farm-level groundwater management: An Australian case study

    Science.gov (United States)

    Sanderson, Matthew R.; Curtis, Allen L.

    2016-05-01

    Cultural factors - values, beliefs, and norms - provide important insights into the environmental attitudes, risk perceptions, and behaviors of the general population. Little is known, however, about the ostensibly complex relationships linking those elements of culture to climate change risk perceptions, especially in the context of farm level decision in the ground water context. This paper addresses that gap through an analysis of survey data provided by irrigators in the Namoi catchment of Australia's Murray-Darling Basin. We use Values-Beliefs-Norms theory to construct multivariate models of the relationship between ground water irrigators' interpretations of climate change risks and their implementation of adaptive water conservation practices. Results indicate that these cultural factors are important explanations of irrigators' climate change risk perceptions, and these risk perceptions are related to adaptive ground water management strategies at the farm level. The implications of the findings are discussed for research on the culture-environment nexus and for outreach designed to encourage agricultural adaptations to climate change.

  2. A New Method for Processing Airborne Gamma Ray Spectrometry Data for Mapping Low Level Contaminations

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

    1999-01-01

    A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia...

  3. 亚洲地下水资源与环境地质系列图及GIS系统结构%Groundwater Resources and Environmental Geology Serial Maps of Asia and the GIS System Structure

    Institute of Scientific and Technical Information of China (English)

    董华; 张健康; 程彦培; 倪增石; 张发旺; 黄志兴; 田廷山; 赵继昌; 高昀; 刘坤

    2011-01-01

    “亚洲地下水资源及环境地质系列图件”(1∶800万)属于洲际尺度图件,包括亚洲水文地质图、亚洲地下水资源图、亚洲地热图和亚洲地下水环境背景图等.针对全球变化,能源危机、资源短缺、环境恶化地质灾害频发的状况,特别是水资源安全保障与地质环境优劣更是直接影响亚洲地区可持续发展,编制上述图件,意义十分重大.亚洲地下水资源及环境地质系列图件,是在亚洲地下水资源及环境地质综合研究基础上,全面分析了国际国内近年来地下水资源与环境地质方面的编图模式,用编制系列图的系统理念,研究制订适合亚洲特点的编图内容及编图方法.应用GIS信息平台,构建亚洲地下水资源与环境GIS系统结构下的数据库,以反映亚洲地下水资源及环境地质时空特征分布规律,为亚洲各国和跨国的自然资源开发利用,水资源规划和地质环境保护防灾减灾,提供科学依据.%"Serial maps of groundwater resource and environmental geology of Asia"(at scale of 1∶8 000 000), including Hydrogeological Map of Asia, Groundwater Resources Map of Asia, Geothermal Map of Asia and Groundwater Environment Background Map of Asia, has been completed based on the research of groundwater resource and environmental geology and overall analysis of mapping pattern of groundwater resource and environmental geology in recent years at home and abroad. The compilation of series maps is of great significance at present for issues over global climate change, energy crisis, resource shortage and environment deterioration and frequent geological hazards we are facing, especially under the condition that water resource safe guarantee and geological environment directly affect the sustainable development in Asia. The mapping content and method suitable for Asia has been developed in consideration of systematical concept of compiling serial maps. The serial maps reflect spatio

  4. Coastal Hazards Maps: Actionable Information for Communities Facing Sea-Level Rise (Invited)

    Science.gov (United States)

    Gibeaut, J. C.; Barraza, E.

    2010-12-01

    Barrier islands along the U.S. Gulf coast remain under increasing pressure from development. This development and redevelopment is occurring despite recent hurricanes, ongoing erosion, and sea-level rise. To lessen the impacts of these hazards, local governments need information in a form that is useful for informing the public, making policy, and enforcing development rules. We recently completed the Galveston Island Geohazards Map for the city of Galveston, Texas and are currently developing maps for the Mustang and South Padre Island communities. The maps show areas that vary in their susceptibility to, and function for, mitigating the effects of geological processes, including sea-level rise, land subsidence, erosion and storm-surge flooding and washover. The current wetlands, beaches and dunes are mapped as having the highest geohazard potential both in terms of their exposure to hazardous conditions and their mitigating effects of those hazards for the rest of the island. These existing “critical environments” are generally protected under existing regulations. Importantly, however, the mapping recognizes that sea-level rise and shoreline retreat are changing the island; therefore, 60-year model projections of the effects of these changes are incorporated into the map. The areas that we project will become wetlands, beaches and dunes in the next 60 years are not protected. These areas are the most difficult to deal with from a policy point of view, yet we must address what happens there if real progress is to be made in how we live with sea-level rise. The geohazards maps draw on decades of geological knowledge of how barrier islands behave and put it in a form that is intuitive to the public and directly useful to planners. Some of the “messages” in the map include: leave salt marshes alone and give them room to migrate inland as sea level rises; set back and move development away from the shoreline to provide space for beaches and protective dunes

  5. ShakeMap/Hazus Scenario Projects and Support for the New Madrid 2011 National Level Exercise

    Science.gov (United States)

    Bausch, D.

    2011-12-01

    The Federal Emergency Management Agency (FEMA) and the U.S. Geological Survey (USGS) have coordinated on the development of new products that support an extensive library of ShakeMap scenarios, largely based on the USGS National Hazard Map sources of earthquakes that are supporting Hazards U.S. (HAZUS) loss estimations. These scenarios are used to support a broad range of emergency management activities, including mitigation, recovery and preparedness planning, as well as exercises for response. We have successfully documented where these scenarios have led to risk reduction actions. To date these have been implemented as pilot studies under the National Earthquake Hazard Reduction Program (NEHRP) in Washington, Utah, Nevada and more recently in New England. As a result of these ShakeMap/HAZUS demonstration projects, we developed a Standard Operating Procedure (SOP) for producing standardized loss mapping templates. These maps and associated tables help translate earthquake loss information to support a broad range of emergency management activities. The SOP includes step by step instructions with standardized map templates, symbology and terminology, which was initiated in support of the New Madrid 2011 National Level Exercise. We developed enhancements to the integration of ShakeMap and Hazus based on the NLE scenarios that can be implemented for other scenarios, as well as real earthquake events. The NLE was especially challenging as 8 States were impacted. A new utility developed internally by FEMA (EQExport) greatly expedited the data flow by automatically exporting the SQL based results into compressed geodatabases, as well as implementing custom map templates, reports and Google Earth KML files. This free open source utility provides the basis for automating map and results production from the Hazus earthquake model. Another development for NLE was to display results data into FlexViewers both inside and outside of FEMA. We benefited from a new real

  6. Groundwater Vulnerability Regions of Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — The regions onThis map represent areas with similar hydrogeologic characteristics thought to represent similar potentials for contamination of groundwater and/or...

  7. Groundwater Depletion in Dhaka City, Bangladesh: A Spatio-temporal Analysis

    Science.gov (United States)

    Jerin, T.; Ishtiaque, A.

    2015-12-01

    Dhaka city, having a population of more than fifteen million, exclusively depends on groundwater as a source of quality drinking water. In recent decades the city is encountering groundwater diminution and the declining scenario is dissimilar in different parts of the city. This paper aims to discuss the groundwater depletion in different parts of Dhaka city from 1990 to 2012 along with the causes and consequences. Groundwater level data of different locations of Dhaka city were collected from Bangladesh Water Development Board (BWDB). The data were processed and analyzed using SPSS and Excel Worksheet; a contour map was generated using ArcGIS 10.0 to outline the contemporary groundwater scenario of Dhaka city and the spatial analyst tool, Inverse Distance Weighted (IDW) was used to prepare the map. In addition, experts' opinions were collected using an in-depth interview strategy in order to provide a better understanding of the causes and consequences of groundwater depletion. The research results show that groundwater in Dhaka city is depleting at an alarming rate; the central part has the worst situation followed by the south-western part. In contrast, northern part has relatively better groundwater condition. Moreover, the peripheral zone exhibits a better condition because of the existence of rivers and wetlands. The interviews reveal that population density and overexploitation are mainly responsible for groundwater depletion; however, various other factors such as the deliberate establishment of deep tube wells, reduction of recharge capacity due to rapid growth of urban structures altogether results in huge drop of water level throughout the city. Rapid decline in groundwater augments the city's exposure towards multiple risks including land subsidence, groundwater pollution and most importantly, paucity of available fresh water that might ultimately results into an urban disaster. Potential solutions to ameliorate this situation include urban greening

  8. Application of a Coupled Vegetation Competition and Groundwater Simulation Model to Study Effects of Sea Level Rise and Storm Surges on Coastal Vegetation

    Directory of Open Access Journals (Sweden)

    Su Yean Teh

    2015-09-01

    Full Text Available Global climate change poses challenges to areas such as low-lying coastal zones, where sea level rise (SLR and storm-surge overwash events can have long-term effects on vegetation and on soil and groundwater salinities, posing risks of habitat loss critical to native species. An early warning system is urgently needed to predict and prepare for the consequences of these climate-related impacts on both the short-term dynamics of salinity in the soil and groundwater and the long-term effects on vegetation. For this purpose, the U.S. Geological Survey’s spatially explicit model of vegetation community dynamics along coastal salinity gradients (MANHAM is integrated into the USGS groundwater model (SUTRA to create a coupled hydrology–salinity–vegetation model, MANTRA. In MANTRA, the uptake of water by plants is modeled as a fluid mass sink term. Groundwater salinity, water saturation and vegetation biomass determine the water available for plant transpiration. Formulations and assumptions used in the coupled model are presented. MANTRA is calibrated with salinity data and vegetation pattern for a coastal area of Florida Everglades vulnerable to storm surges. A possible regime shift at that site is investigated by simulating the vegetation responses to climate variability and disturbances, including SLR and storm surges based on empirical information.

  9. Application of a coupled vegetation competition and groundwater simulation model to study effects of sea level rise and storm surges on coastal vegetation

    Science.gov (United States)

    Teh, Su Yean; Turtora, Michael; DeAngelis, Don; Jiang Jiang,; Pearlstine, Leonard G.; Smith, Thomas; Koh, Hock Lye

    2015-01-01

    Global climate change poses challenges to areas such as low-lying coastal zones, where sea level rise (SLR) and storm-surge overwash events can have long-term effects on vegetation and on soil and groundwater salinities, posing risks of habitat loss critical to native species. An early warning system is urgently needed to predict and prepare for the consequences of these climate-related impacts on both the short-term dynamics of salinity in the soil and groundwater and the long-term effects on vegetation. For this purpose, the U.S. Geological Survey’s spatially explicit model of vegetation community dynamics along coastal salinity gradients (MANHAM) is integrated into the USGS groundwater model (SUTRA) to create a coupled hydrology–salinity–vegetation model, MANTRA. In MANTRA, the uptake of water by plants is modeled as a fluid mass sink term. Groundwater salinity, water saturation and vegetation biomass determine the water available for plant transpiration. Formulations and assumptions used in the coupled model are presented. MANTRA is calibrated with salinity data and vegetation pattern for a coastal area of Florida Everglades vulnerable to storm surges. A possible regime shift at that site is investigated by simulating the vegetation responses to climate variability and disturbances, including SLR and storm surges based on empirical information.

  10. Groundwater flow modeling of periods with periglacial and glacial climate conditions for the safety assessment of the proposed high-level nuclear waste repository site at Forsmark, Sweden

    Science.gov (United States)

    Vidstrand, Patrik; Follin, Sven; Selroos, Jan-Olof; Näslund, Jens-Ove

    2014-09-01

    The impact of periglacial and glacial climate conditions on groundwater flow in fractured crystalline rock is studied by means of groundwater flow modeling of the Forsmark site, which was recently proposed as a repository site for the disposal of spent high-level nuclear fuel in Sweden. The employed model uses a thermal-hydraulically coupled approach for permafrost modeling and discusses changes in groundwater flow implied by the climate conditions found over northern Europe at different times during the last glacial cycle (Weichselian glaciation). It is concluded that discharge of particles released at repository depth occurs very close to the ice-sheet margin in the absence of permafrost. If permafrost is included, the greater part discharges into taliks in the periglacial area. During a glacial cycle, hydraulic gradients at repository depth reach their maximum values when the ice-sheet margin passes over the site; at this time, also, the interface between fresh and saline waters is distorted the most. The combined effect of advances and retreats during several glaciations has not been studied in the present work; however, the results indicate that hydrochemical conditions at depth in the groundwater flow model are almost restored after a single event of ice-sheet advance and retreat.

  11. Quality of groundwater resources in Afghanistan.

    Science.gov (United States)

    Hayat, Ehsanullah; Baba, Alper

    2017-07-01

    Water is the main source of energy production and economy in Afghanistan where agriculture accounts for more than 50% of the country's gross domestic product (GDP). Access to safe drinking water is still a problem in the country, which has caused different health issues and even child mortality especially in rural areas. Groundwater is the main source of drinking water in the country. However, little knowledge is available about the quality of groundwater throughout the entire country, and its quality has not been investigated extensively yet like in other countries in the world. While most people think that consuming groundwater is a reliable and safe source of drinking water for health, the United Nations (UN) agencies report various kinds of waterborne diseases and even child mortalities due to drinking water quality in the country. In this article, significant geogenic and anthropogenic factors that play a vital role in groundwater contamination of the country are identified and explained. Different geogenic contaminations such as arsenic, fluoride, sulfate, and boron occur in several areas of Afghanistan that have a direct effect on human health. The water quality mapping for Afghanistan is completed for half of the country, which shows that groundwater is plagued by high levels of fluoride and arsenic in some areas. The water quality mapping of the other half of the country cannot be completed due to security concerns currently. Also, there are different kinds of waterborne diseases such as diarrhea, cholera, and dysentery that can be seen in different parts of the country because of anthropogenic activities which continuously deteriorate groundwater.

  12. Surface- and ground-water relations on the Portneuf river, and temporal changes in ground-water levels in the Portneuf Valley, Caribou and Bannock Counties, Idaho, 2001-02

    Science.gov (United States)

    Barton, Gary J.

    2004-01-01

    high flows. Conveyance losses in the Pebble-Topaz reach were greatest, about 283 cubic feet per second, during the spring regulated high flows and were attributed to a hydroelectric project.Comparison of water levels in 30 wells in the Portneuf Valley during September and October 1968 and 2001 indicated long-term declines since 1968; the median decline was 3.4 feet. September and October were selected for characterizing long-term ground-water-level fluctuations because declines associated with irrigation reach a maximum at the end of the irrigation season. The average annual snowpack in the study area has declined significantly; 1945 85 average annual snowpack was 16.1 inches, whereas 1986 through 2002 average annual snowpack was 11.6 inches. Water-level declines during 1998 2002 may be partially attributable to the extended dry climatic conditions. It is unclear whether the declines could be partially attributed to increases in ground-water withdrawals. Between 1968 and 1980, water rights for ground-water withdrawals nearly doubled from 23,500 to 46,000 acre-feet per year. During this period, ground-water levels were relatively constant and did not exhibit a declining trend that could be related to increased ground-water withdrawal rights. However, ground-water withdrawals are not measured in the valley; thus, the amount of water pumped is not known. Since the 1990s, there have been several years when the Chesterfield Reservoir has not completely refilled, and the water in storage behind the reservoir has been depleted by the middle of the irrigation season. In this situation, surface-water diversions for irrigation were terminated before the end of the irrigation season, and irrigators, who were relying in part on diversions from the Portneuf River, had to rely solely on ground water as an alternate supply. Smaller volumes of water in the Chesterfield Reservoir since the 1990s indicate a growing demand for ground-water supplies.

  13. Declining Groundwater Levels in North India: Understanding Sources of Irrigation Inefficiency

    Science.gov (United States)

    O'Keeffe, J.; Buytaert, W.; Mijic, A.; Brozovic, N.

    2014-12-01

    Over the last half century, the green revolution has transformed India from a famine-prone, drought-susceptible country, into the world's third largest grain producer and one of the most intensely irrigated regions on the planet. This is in no small part due to the country's vast water resources along with an increase in tubewells and more advanced abstraction methods. While agricultural intensification has had undeniable benefits, it has, and continues to have a significant impact on water resources. Unless solutions which take into consideration the ever evolving socio-economic, hydrological and climatic conditions are found, India's agricultural future looks bleak.This research examines the irrigation behaviour of farmers, using data collected during field work in the State of Uttar Pradesh within the Ganges Basin of North India. Significant differences in farmer behaviour and irrigation practices are highlighted, not only between State districts but between individual farmers. This includes the volume of irrigation water applied and the price paid, as well as differences in the yields of crops produced. Analyses of results suggest that this is due to a number of factors, particularly the source of irrigation water. Study areas which had access to cheaper, but crucially less reliable, canal water were found to invest in more efficient water saving technologies in order to reduce the overall cost of irrigation during periods where less expensive canal water is not available. As a result, overall water use and irrigation cost is lower and yields are higher despite very similar climatic conditions. While cheap canal water is not an option for all farmers, the results show that the introduction of more efficient water saving technologies, despite the significant capital expenditure is a viable option for many farmers and costs can be recovered in a relatively short space of time. In addition, the reduction of declining water levels mean that water is abstracted from

  14. The Maryland Coastal Plain Aquifer Information System: A GIS-based tool for assessing groundwater resources

    Science.gov (United States)

    Andreasen, David C.; Nardi, Mark R.; Staley, Andrew W.; Achmad, Grufron; Grace, John W.

    2016-01-01

    Groundwater is the source of drinking water for ∼1.4 million people in the Coastal Plain Province of Maryland (USA). In addition, groundwater is essential for commercial, industrial, and agricultural uses. Approximately 0.757 × 109 L d–1 (200 million gallons/d) were withdrawn in 2010. As a result of decades of withdrawals from the coastal plain confined aquifers, groundwater levels have declined by as much as 70 m (230 ft) from estimated prepumping levels. Other issues posing challenges to long-term groundwater sustainability include degraded water quality from both man-made and natural sources, reduced stream base flow, land subsidence, and changing recharge patterns (drought) caused by climate change. In Maryland, groundwater supply is managed primarily by the Maryland Department of the Environment, which seeks to balance reasonable use of the resource with long-term sustainability. The chief goal of groundwater management in Maryland is to ensure safe and adequate supplies for all current and future users through the implementation of appropriate usage, planning, and conservation policies. To assist in that effort, the geographic information system (GIS)–based Maryland Coastal Plain Aquifer Information System was developed as a tool to help water managers access and visualize groundwater data for use in the evaluation of groundwater allocation and use permits. The system, contained within an ESRI ArcMap desktop environment, includes both interpreted and basic data for 16 aquifers and 14 confining units. Data map layers include aquifer and ­confining unit layer surfaces, aquifer extents, borehole information, hydraulic properties, time-series groundwater-level data, well records, and geophysical and lithologic logs. The aquifer and confining unit layer surfaces were generated specifically for the GIS system. The system also contains select groundwater-quality data and map layers that quantify groundwater and surface-water withdrawals. The aquifer

  15. Synoptic Multi-tracer Sensing for Mapping Groundwater-Surface Water Discharges and Estimating Reactive Nitrate Loading along a Gaining Lowland River

    Science.gov (United States)

    Pai, H.; Villamizar, S. R.; Harmon, T. C.

    2015-12-01

    Distributed groundwater (GW) discharges to surface water (GW-SW discharges) in river systems remain difficult to delineate across spatiotemporal scales yet are important to understand with respect to link land management practices to nonpoint source constituent loading. In this work, we develop and test a relatively low-cost strategy for watershed-scale mapping distributed GW-SW discharges for nitrate (NO3-) in a gaining lowland river. We employ ambient GW specific conductance (SC) and nitrate as tracers using a high-resolution longitudinal synoptic sensing along the lower Merced River (38 river km) in Central California. Using available GW SC, we first calibrate a simple distributed GW-SW discharge model (segment-by-segment mixing model) at 1-km resolution for 13 synoptic sampling events at upstream daily flows ranging from 1.3 to 31.6 m3s-1. We then apply the distributed discharge estimates to a similar distributed nitrate loading model, adding a first-order decay term representing shallow aquifer denitrification along the GW-SW flow path. Best-fitting model outcomes (RMSE = 0.06-0.98 mg L-1) were found when we censored GW nitrate data following below detection thresholds (typically 0.5 mg L-1 NO3-N). The range of reach-estimated dimensionless denitrification rate terms varied from 0 to 0.432, which is slightly lower than previous regional results (0.17-1.06), accounting for our reach travel time.

  16. Questa baseline and pre-mining ground-water quality investigation. 5. Well installation, water-level data, and surface- and ground-water geochemistry in the Straight Creek drainage basin, Red River Valley, New Mexico, 2001-03

    Science.gov (United States)

    Naus, Cheryl A.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Donohoe, Lisa C.; Hunt, Andrew G.; Paillet, Frederick L.; Morin, Roger H.; Verplanck, Philip L.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, northern New Mexico. The primary approach is to determine the processes controlling ground-water chemistry at an unmined, off-site, proximal analog. The Straight Creek drainage basin, chosen for this purpose, consists of the same quartz-sericite-pyrite altered andesitic and rhyolitic volcanic rock of Tertiary age as the mine site. The weathered and rugged volcanic bedrock surface is overlain by heterogeneous debris-flow deposits that interfinger with alluvial deposits near the confluence of Straight Creek and the Red River. Pyritized rock in the upper part of the drainage basin is the source of acid rock drainage (pH 2.8-3.3) that infiltrates debris-flow deposits containing acidic ground water (pH 3.0-4.0) and bedrock containing water of circumneutral pH values (5.6-7.7). Eleven observation wells were installed in the Straight Creek drainage basin. The wells were completed in debris-flow deposits, bedrock, and interfingering debris-flow and Red River alluvial deposits. Chemical analyses of ground water from these wells, combined with chemical analyses of surface water, water-level data, and lithologic and geophysical logs, provided information used to develop an understanding of the processes contributing to the chemistry of ground water in the Straight Creek drainage basin. Surface- and ground-water samples were routinely collected for determination of total major cations and selected trace metals; dissolved major cations, selected trace metals, and rare-earth elements; anions and alkalinity; and dissolved-iron species. Rare-earth elements were determined on selected samples only. Samples were collected for determination of dissolved organic carbon, mercury, sulfur isotopic composition (34S and 18O of sulfate), and water isotopic composition (2H and 18O) during

  17. Identification and level of organochlorine insecticide contamination in groundwater and iridology analysis for people in Upper Citarum cascade

    Science.gov (United States)

    Oginawati, K.; Pratama, M. A.

    2016-03-01

    Organochlorines are the main pollutants in the class of persistent organic pollutants which are types of pollutants that are being questioned worldwide due to chronic persistence, toxicity and bioaccumulation. Human around the Citarum River are still using groundwater as a drinking source. It is very risky for people health that consume groundwater because in 2009 the application of organochlorine still found in the Upper Citarum watershed rice field and had potential to contaminate groundwater. Groundwater was analyzed with nine species belonging to the organochlorine pollutants Organic Peristent types. 7 types of organochlorinesAldrin was detected with an average concentration of 0.09 ppb, dieldrin with an average concentration of 24 ppb, heptaklor with an average concentration of 0.51 ppb, with concentrations of endosulfan on average 0.73 ppb, DDT with average concentration of 0.13 ppb, Lindan with an average concentration of 1.2 ppb, endrin with an average concentration of 0.03 ppb. Types with the highest concentration of organochlorine a lindan and endosulfan. Residues of aldrin, dieldrin and heptaklor in groundwater already exceeds the quality standards for drinking water Permenkes 492/2010. Based on the iridology analysis obtained several systems are expected to nervous, immune and reproductive system disorders and toxin deposits under the skin.

  18. Discussion on the Initial Water Level of Groundwater%关于地下水初见水位的讨论

    Institute of Scientific and Technical Information of China (English)

    尤苏南

    2012-01-01

    This paper presents the analysis and discussion on initial water level of groundwater according to different understanding offered by investigation competitors; besides, it also puts forward the author's own ideas for colleagues in reference.%针对勘察同行们对地下水初见水位的不同理解,进行分析和讨论,提出了自己的看法,可供勘察同行们工作中参考.

  19. Estimating hydraulic parameters of a heterogeneous aquitard using long-term multi-extensometer and groundwater level data

    Science.gov (United States)

    Zhuang, Chao; Zhou, Zhifang; Illman, Walter A.; Guo, Qiaona; Wang, Jinguo

    2017-05-01

    The classical aquitard-drainage model COMPAC has been modified to simulate the compaction process of a heterogeneous aquitard consisting of multiple sub-units (Multi-COMPAC). By coupling Multi-COMPAC with the parameter estimation code PEST++, the vertical hydraulic conductivity (K v) and elastic (S ske) and inelastic (S skp) skeletal specific-storage values of each sub-unit can be estimated using observed long-term multi-extensometer and groundwater level data. The approach was first tested through a synthetic case with known parameters. Results of the synthetic case revealed that it was possible to accurately estimate the three parameters for each sub-unit. Next, the methodology was applied to a field site located in Changzhou city, China. Based on the detailed stratigraphic information and extensometer data, the aquitard of interest was subdivided into three sub-units. Parameters K v, S ske and S skp of each sub-unit were estimated simultaneously and then were compared with laboratory results and with bulk values and geologic data from previous studies, demonstrating the reliability of parameter estimates. Estimated S skp values ranged within the magnitude of 10-4 m-1, while K v ranged over 10-10-10-8 m/s, suggesting moderately high heterogeneity of the aquitard. However, the elastic deformation of the third sub-unit, consisting of soft plastic silty clay, is masked by delayed drainage, and the inverse procedure leads to large uncertainty in the S ske estimate for this sub-unit.

  20. Estimating hydraulic parameters of a heterogeneous aquitard using long-term multi-extensometer and groundwater level data

    Science.gov (United States)

    Zhuang, Chao; Zhou, Zhifang; Illman, Walter A.; Guo, Qiaona; Wang, Jinguo

    2017-09-01

    The classical aquitard-drainage model COMPAC has been modified to simulate the compaction process of a heterogeneous aquitard consisting of multiple sub-units (Multi-COMPAC). By coupling Multi-COMPAC with the parameter estimation code PEST++, the vertical hydraulic conductivity ( K v) and elastic ( S ske) and inelastic ( S skp) skeletal specific-storage values of each sub-unit can be estimated using observed long-term multi-extensometer and groundwater level data. The approach was first tested through a synthetic case with known parameters. Results of the synthetic case revealed that it was possible to accurately estimate the three parameters for each sub-unit. Next, the methodology was applied to a field site located in Changzhou city, China. Based on the detailed stratigraphic information and extensometer data, the aquitard of interest was subdivided into three sub-units. Parameters K v, S ske and S skp of each sub-unit were estimated simultaneously and then were compared with laboratory results and with bulk values and geologic data from previous studies, demonstrating the reliability of parameter estimates. Estimated S skp values ranged within the magnitude of 10-4 m-1, while K v ranged over 10-10-10-8 m/s, suggesting moderately high heterogeneity of the aquitard. However, the elastic deformation of the third sub-unit, consisting of soft plastic silty clay, is masked by delayed drainage, and the inverse procedure leads to large uncertainty in the S ske estimate for this sub-unit.

  1. Limits to Global Groundwater Consumption

    Science.gov (United States)

    Graaf, I. D.; Van Beek, R.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

    2015-12-01

    In regions with frequent water stress and large aquifer systems, groundwater is often used as an additional fresh water source. For many regions of the world groundwater abstraction exceeds groundwater recharge and persistent groundwater depletion occurs. The most direct effect of groundwater depletion is declining of water tables, leading to reduced groundwater discharge needed to sustain base-flow to e.g. rivers. Next to that, pumping costs increase, wells dry up and land subsidence occurs. These problems are expected to increase in the near future due to growing population and climate changes. This poses the urgent question of what the limits are of groundwater consumption worldwide. We simulate global water availability (5 arc-minute resolution, for 1960-2050) using the hydrological model PCR-GLOBWB (van Beek et al. 2011), coupled to a groundwater model based on MODFLOW (de Graaf et al. 2015), allowing for groundwater - surface water interactions. The groundwater model includes a parameterization of world's confined and unconfined aquifer systems needed for a realistic simulation of groundwater head dynamics. Water demands are included (from Wada et al. 2014). We study the limits to water consumption, focusing on locally attainable groundwater and groundwater levels critical to rivers to sustain low flows. We show an increasing trend (1960-2050) in groundwater head declines, due to increase in groundwater demand. Also, stream flow will decrease and low flow conditions will occur more frequent and will be longer in duration in the near future, especially for irrigated areas. Next to that, we provide a global overview of the years it takes until groundwater gets unattainable for e.g. a local farmer (100 m below land-surface used as a proxy), and estimate the increase in pumping cost for the near future. The results show where and when limits of groundwater consumption are reached globally.

  2. Evaluation of levels of antibiotic resistance in groundwater-derived E. coli isolates in the Midwest of Ireland and elucidation of potential predictors of resistance

    Science.gov (United States)

    O'Dwyer, Jean; Hynds, Paul; Pot, Matthieu; Adley, Catherine C.; Ryan, Michael P.

    2017-06-01

    Antibiotic-resistant (pathogenic and non-pathogenic) organisms and genes are now acknowledged as significant emerging aquatic contaminants with potentially adverse human and ecological health impacts, and thus require monitoring. This study is the first to investigate levels of resistance among Irish groundwater (private wells) samples; Escherichia coli isolates were examined against a panel of commonly prescribed human and veterinary therapeutic antibiotics, followed by determination of the causative factors of resistance. Overall, 42 confirmed E. coli isolates were recovered from a groundwater-sampling cohort. Resistance to the human panel of antibiotics was moderate; nine (21.4%) E. coli isolates demonstrated resistance to one or more human antibiotics. Conversely, extremely high levels of resistance to veterinary antibiotics were found, with all isolates presenting resistance to one or more veterinary antibiotics. Particularly high levels of resistance (93%) were found with respect to the aminoglycoside class of antibiotics. Results of statistical analysis indicate a significant association between the presence of human (multiple) antibiotic resistance ( p = 0.002-0.011) and both septic tank density and the presence of vulnerable sub-populations (antibiotics, results point to a significant relationship ( p = antibiotic resistant E. coli. Groundwater continues to be an important resource in Ireland, particularly in rural areas; thus, results of this preliminary study offer a valuable insight into the prevalence of antibiotic resistance in the hydrogeological environment and establish a need for further research with a larger geological diversity.

  3. Groundwater management for agriculture and nature: an economic analysis

    NARCIS (Netherlands)

    Hellegers, P.J.G.J.

    2001-01-01

    Key words: desiccation of nature, economics of water management, groundwater extraction, groundwater level management, ecohydrology, agriculture, policy instruments.

    As a result of declining groundwater levels, nature in the Netherlands is suffering

  4. Groundwater Management for Agriculture and Nature : an Economic Analysis

    NARCIS (Netherlands)

    Hellegers, P.

    2001-01-01

    Key words: desiccation of nature, economics of water management, groundwater extraction, groundwater level management, ecohydrology, agriculture, policy instruments.As a result of declining groundwater levels, nature in the Netherlands is suffering from desiccation. Since measures taken to raise gro

  5. Applying factor analysis combined with kriging and information entropy theory for mapping and evaluating the stability of groundwater quality variation in Taiwan.

    Science.gov (United States)

    Shyu, Guey-Shin; Cheng, Bai-You; Chiang, Chi-Ting; Yao, Pei-Hsuan; Chang, Tsun-Kuo

    2011-04-01

    In Taiwan many factors, whether geological parent materials, human activities, and climate change, can affect the groundwater quality and its stability. This work combines factor analysis and kriging with information entropy theory to interpret the stability of groundwater quality variation in Taiwan between 2005 and 2007. Groundwater quality demonstrated apparent differences between the northern and southern areas of Taiwan when divided by the Wu River. Approximately 52% of the monitoring wells in southern Taiwan suffered from progressing seawater intrusion, causing unstable groundwater quality. Industrial and livestock wastewaters also polluted 59.6% of the monitoring wells, resulting in elevated EC and TOC concentrations in the groundwater. In northern Taiwan, domestic wastewaters polluted city groundwater, resulting in higher NH(3)-N concentration and groundwater quality instability was apparent among 10.3% of the monitoring wells. The method proposed in this study for analyzing groundwater quality inspects common stability factors, identifies potential areas influenced by common factors, and assists in elevating and reinforcing information in support of an overall groundwater management strategy.

  6. Shallow groundwater in the Matanuska-Susitna Valley, Alaska—Conceptualization and simulation of flow

    Science.gov (United States)

    Kikuchi, Colin P.

    2013-01-01

    estimated during field investigations on several small streams. Regional groundwater flow patterns were characterized by synthesizing previous water-table maps with a synoptic water-level measurement conducted during 2009. Time-series water-level data were collected at groundwater and lake monitoring stations over the study period (2009–present). Comparison of historical groundwater-level records with time-series groundwater-level data collected during this study showed similar patterns in groundwater-level fluctuation in response to precipitation. Groundwater-age data collected during previous studies show that water moves quickly through the groundwater system, suggesting that the system responds quickly to changes in climate forcing. Similarly, the groundwater system quickly returns to long-term average conditions following variability due to seasonal or interannual changes in precipitation. These analyses indicate that the groundwater system is in a state of dynamic equilibrium, characterized by water-level fluctuation about a constant average state, with no long-term trends in aquifer-system storage. To address the second study goal, a steady-state groundwater flow model was developed to simulate regional groundwater flow patterns. The groundwater flow model was bounded by physically meaningful hydrologic features, and appropriate internal model boundaries were specified on the basis of conceptualization of the groundwater system resulting in a three-layer model. Calibration data included 173 water‑level measurements and 18 measurements of streamflow gains and losses along small streams. Comparison of simulated and observed heads and flows showed that the model accurately simulates important regional characteristics of the groundwater flow system. This model is therefore appropriate for studying regional-scale groundwater availability. Mismatch between model-simulated and observed hydrologic quantities is likely because of the coarse grid size of the model and

  7. State-wide space-time water table mapping: cautionary tales, tribulations and resolution

    Science.gov (United States)

    Peterson, T. J.; Cheng, X.; Carrara, E.; Western, A. W.; Costelloe, J. F.; Frost, A. J.; McAuley, C. V.

    2015-12-01

    Historically, insufficient quantitative value has been derived from state groundwater monitoring networks. Water level data are occasionally used for calibrating local scale groundwater models and for graphical analysis, but very rarely are they used to identify regional groundwater processes and quantify changes in groundwater dynamics over time. Potentiometric maps have occasionally been derived to assist understanding of regional processes but generally they are derived for one point in time, often simply using an average water level over a year or season. Consequently, dynamics of regional groundwater over time has been compromised. Kriging with external drift (KED) has been a widely adopted approach for regional scale potentiometric mapping in recent years. However, it has a number of unacknowledged fundamental weaknesses - specifically, excessive noise in the head, sensitivity to observation errors and questionable estimation in upland regions and in coastal regions dominated by radial flow. These weaknesses are illustrated and then a multivariate localised colocated cokriging approach is proposed that locally reduces the excessive noise from KED and incorporates the coast line and streams into the estimation. Combined with the temporal interpolation of groundwater head (Peterson & Western, 2014), the approach allows regional scale mapping for a single point in time. To illustrate the approach, the monthly water table level was mapped across Victoria, Australia, from 1985 to 2014. Using the maps, the location and the nature/magnitude of major changes in groundwater dynamics were identified and the surface-groundwater connectivity of major rivers was estimated over time. While geological knowledge can be incorporated, this approach allows data-driven insights to be derived from groundwater monitoring networks without the usual assumptions required for numerical groundwater modeling. Peterson, T. J., and A. W. Western (2014), Nonlinear time-series modeling of

  8. METHOD OF HIGH-LEVEL TECHNOLOGY MAPPING BASED ON KNOWLEDGE(RULE)

    Institute of Scientific and Technical Information of China (English)

    Ma Cong; Wang Zuojian; Liu Mingye

    2001-01-01

    This paper studies the linkage problem between the result of high-level synthesis and back-end technology, presents a method of high-level technology mapping based on knowl edge, and studies deeply all of its important links such as knowledge representation, knowledge utility and knowledge acquisition. It includes: (1) present a kind of expanded production about knowledge of circuit structure; (2) present a VHDL-based method to acquire knowledge of tech nology mapping; (3) provide solution control strategy and algorithm of knowledge utility; (4)present a half-automatic maintenance method, which can find redundance and contradiction of knowledge base; (5) present a practical method to embed the algorithm into knowledge system to decrease complexity of knowledge base. A system has been developed and linked with three kinds of technologies, so verified the work of this paper.

  9. MODFLOW-NWT model used to evaluate the potential effect of groundwater pumpage and increased sea level on canal leakage and regional groundwater flow in Miami-Dade County, Florida

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A three-dimensional, surface-water/groundwater model (MODFLOW-NWT with the Surface-Water Routing Process) was developed to the predict the effects of groundwater...

  10. Mapping crime levels and court efficiency per magisterial district in South Africa

    CSIR Research Space (South Africa)

    Schmitz, Peter MU

    2002-12-01

    Full Text Available magisterial district. By mapping crime categories such as sexual offences, it is possible to identify magisterial districts with high occurrences of these crimes, and hence districts that need courts specializing in sexual offences. 1... function will be created. This function will assume responsibility for the ongoing monitoring and management of resources within the Department in order to ensure that justice at a local level is dispensed effectively and efficiently, through...

  11. Mapping crime levels and court efficiency per magisterial district in South Africa.

    CSIR Research Space (South Africa)

    Schmitz, Peter MU

    2002-12-01

    Full Text Available magisterial district. By mapping crime categories such as sexual offences, it is possible to identify magisterial districts with high occurrences of these crimes, and hence districts that need courts specializing in sexual offences. 1... function will be created. This function will assume responsibility for the ongoing monitoring and management of resources within the Department in order to ensure that justice at a local level is dispensed effectively and efficiently, through...

  12. Future Flows Hydrology: an ensemble of daily river flow and monthly groundwater levels for use for climate change impact assessment across Great Britain

    Directory of Open Access Journals (Sweden)

    C. Prudhomme

    2012-12-01

    Full Text Available The dataset Future Flows Hydrology was developed as part of the project "Future Flows and Groundwater Levels" to provide a consistent set of transient daily river flow and monthly groundwater levels projections across England, Wales and Scotland to enable the investigation of the role of climate variability on river flow and groundwater levels nationally and how this may change in the future.

    Future Flows Hydrology is derived from Future Flows Climate, a national ensemble projection derived from the Hadley Centre's ensemble projection HadRM3-PPE to provide a consistent set of climate change projections for the whole of Great Britain at both space and time resolutions appropriate for hydrological applications. Three hydrological models and one groundwater level model were used to derive Future Flows Hydrology, with 30 river sites simulated by two hydrological models to enable assessment of hydrological modelling uncertainty in studying the impact of climate change on the hydrology.

    Future Flows Hydrology contains an 11-member ensemble of transient projections from January 1951 to December 2098, each associated with a single realisation from a different variant of HadRM3 and a single hydrological model. Daily river flows are provided for 281 river catchments and monthly groundwater levels at 24 boreholes as .csv files containing all 11 ensemble members. When separate simulations are done with two hydrological models, two separate .csv files are provided.

    Because of potential biases in the climate-hydrology modelling chain, catchment fact sheets are associated with each ensemble. These contain information on the uncertainty associated with the hydrological modelling when driven using observed climate and Future Flows Climate for a period representative of the reference time slice 1961–1990 as described by key hydrological statistics. Graphs of projected changes for selected hydrological indicators are also provided for

  13. Future Flows Hydrology: an ensemble of daily river flow and monthly groundwater levels for use for climate change impact assessment across Great Britain

    Directory of Open Access Journals (Sweden)

    C. Prudhomme

    2013-03-01

    Full Text Available The dataset Future Flows Hydrology was developed as part of the project "Future Flows and Groundwater Levels'' to provide a consistent set of transient daily river flow and monthly groundwater level projections across England, Wales and Scotland to enable the investigation of the role of climate variability on river flow and groundwater levels nationally and how this may change in the future. Future Flows Hydrology is derived from Future Flows Climate, a national ensemble projection derived from the Hadley Centre's ensemble projection HadRM3-PPE to provide a consistent set of climate change projections for the whole of Great Britain at both space and time resolutions appropriate for hydrological applications. Three hydrological models and one groundwater level model were used to derive Future Flows Hydrology, with 30 river sites simulated by two hydrological models to enable assessment of hydrological modelling uncertainty in studying the impact of climate change on the hydrology. Future Flows Hydrology contains an 11-member ensemble of transient projections from January 1951 to December 2098, each associated with a single realisation from a different variant of HadRM3 and a single hydrological model. Daily river flows are provided for 281 river catchments and monthly groundwater levels at 24 boreholes as .csv files containing all 11 ensemble members. When separate simulations are done with two hydrological models, two separate .csv files are provided. Because of potential biases in the climate–hydrology modelling chain, catchment fact sheets are associated with each ensemble. These contain information on the uncertainty associated with the hydrological modelling when driven using observed climate and Future Flows Climate for a period representative of the reference time slice 1961–1990 as described by key hydrological statistics. Graphs of projected changes for selected hydrological indicators are also provided for the 2050s time slice

  14. Derivation of Threshold Values for Groundwater in Romania, in order to distinguish Point & Diffuse pollution from natural background levels

    NARCIS (Netherlands)

    Schipper, P.N.M.; Radu, E.; Vliegenthart, F.; Balaet, R.

    2010-01-01

    Romania aims to adopt and implement the European Union's legislation, also including that for the field of water management. Like other countries, groundwater in Romania is locally polluted from point sources, such as leaking landfills, as well as from diffuse pollution sources, include fertilizers,

  15. Groundwater response to the 2014 pulse flow in the Colorado River Delta

    Science.gov (United States)

    Kennedy, Jeffrey; Rodriguez-Burgueno, Eliana; Ramirez-Hernandez, Jorge

    2017-01-01

    During the March-May 2014 Colorado River Delta pulse flow, approximately 102 × 106 m3 (82,000 acre-feet) of water was released into the channel at Morelos Dam, with additional releases further downstream. The majority of pulse flow water infiltrated and recharged the regional aquifer. Using groundwater-level and microgravity data we mapped the spatial and temporal distribution of changes in aquifer storage associated with pulse flow. Surface-water losses to infiltration were greatest around the Southerly International Boundary, where a lowered groundwater level owing to nearby pumping created increased storage potential as compared to other areas with shallower groundwater. Groundwater levels were elevated for several months after the pulse flow but had largely returned to pre-pulse levels by fall 2014. Elevated groundwater levels in the limitrophe (border) reach extended about 2 km to the east around the midway point between the Northerly and Southerly International Boundaries, and about 4 km to the east at the southern end. In the southern part of the delta, although total streamflow in the channel was less due to upstream infiltration, augmented deliveries through irrigation canals and possible irrigation return flows created sustained increases in groundwater levels during summer 2014. Results show that elevated groundwater levels and increases in groundwater storage were relatively short lived (confined to calendar year 2014), and that depressed water levels associated with groundwater pumping around San Luis, Arizona and San Luis Rio Colorado, Sonora cause large, unavoidable infiltration losses of in-channel water to groundwater in the vicinity.

  16. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Volume 2. Special test cases

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-08-01

    This document was written for the National Low-Level Waste Management Program to provide guidance for managers and site operators who need to select ground-water transport codes for assessing shallow-land burial site performance. The guidance given in this report also serves the needs of applications-oriented users who work under the direction of a manager or site operator. The guidelines are published in two volumes designed to support the needs of users having different technical backgrounds. An executive summary, published separately, gives managers and site operators an overview of the main guideline report. Volume 1, titled ''Guideline Approach,'' consists of Chapters 1 through 5 and a glossary. Chapters 2 through 5 provide the more detailed discussions about the code selection approach. This volume, Volume 2, consists of four appendices reporting on the technical evaluation test cases designed to help verify the accuracy of ground-water transport codes. 20 refs.

  17. Optical mapping of a rice B AC clone using restriction endonuclease and imaging with fluorescent microscopy at single molecule level

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A method of constructing restriction map by optical mapping and single molecule fluorescent microscopy is described. DNA molecules were aligned and adsorbed on a glass coverslip surface by a mbdified "molecular combing"technique, and then the surface-immobilized DNAs were cleaved in situ with a restriction endonuclease. Individual DNA molecules digested by the endonuclease EcoR I were observable with fluorescent microscopy. Using optical mapping, a physical map of a rice bacterial artificial chromosome clone was constructed. This method will facilitate genomic mapping and tracing the dynamic process in real time at a single molecule level with fluorescence microscopy.

  18. Learning about A level physics students’ understandings of particle physics using concept mapping

    Science.gov (United States)

    Gourlay, H.

    2017-01-01

    This paper describes a small-scale piece of research using concept mapping to elicit A level students’ understandings of particle physics. Fifty-nine year 12 (16- and 17 year-old) students from two London schools participated. The exercise took place during school physics lessons. Students were instructed how to make a concept map and were provided with 24 topic-specific key words. Students’ concept maps were analysed by identifying the knowledge propositions they represented, enumerating how many students had made each one, and by identifying errors and potential misconceptions, with reference to the specification they were studying. The only correct statement made by a majority of students in both schools was that annihilation takes place when matter and antimatter collide, although there was evidence that some students were unable to distinguish between annihilation and pair production. A high proportion of students knew of up, down and strange quarks, and that the electron is a lepton. However, some students appeared to have a misconception that everything is made of quarks. Students found it harder to classify tau particles than they did electrons and muons. Where students made incorrect links about muons and tau particles their concept maps suggested that they thought they were mesons or quarks.

  19. Arctic Research Mapping Application (ARMAP) Showcases discovery level metadata for US Funded Research Projects

    Science.gov (United States)

    Score, R.; Gaylord, A. G.; Kassin, A.; Cody, R. P.; Copenhaver, W.; Manley, W. F.; Dover, M.; Tweedie, C. E.

    2014-12-01

    The Arctic Research Mapping Application (ARMAP) is a suite of online applications and data services that support Arctic science by providing project tracking information (who's doing what, when and where in the region) for United States Government funded projects. Development of an interagency standard for tracking discovery level metadata for projects has been achieved through collaboration with the Alaska Data Integration work group. The US National Science Foundation plus 17 other agencies and organizations have adopted the standard with several entities successfully implementing XML based REST webservices. With ARMAP's web mapping applications and data services (http://armap.org), users can search for research projects by location, year, funding program, keyword, investigator, and discipline, among other variables. Key information about each project is displayed within the application with links to web pages that provide additional information. The ARMAP 2D mapping application has been significantly enhanced to include support for multiple projections, improved base maps, additional reference data layers, and optimization for better performance. In 2014, ship tracks for US National Science Foundation supported vessel based surveys have been expanded. These enhancements have been made to increase awareness of projects funded by numerous entities in the Arctic, enhance coordination for logistics support, help identify geographic gaps in research efforts and potentially foster more collaboration amongst researchers working in the region. Additionally, ARMAP can be used to demonstrate past, present, and future research efforts supported by the U.S. Government.

  20. A Novel Bit-level Image Encryption Method Based on Chaotic Map and Dynamic Grouping

    Institute of Scientific and Technical Information of China (English)

    张国基; 沈彦

    2012-01-01

    In this paper,a novel bit-level image encryption method based on dynamic grouping is proposed.In the proposed method,the plain-image is divided into several groups randomly,then permutation-diffusion process on bit level is carried out.The keystream generated by logistic map is related to the plain-image,which confuses the relationship between the plain-image and the cipher-image.The computer simulation results of statistical analysis,information entropy analysis and sensitivity analysis show that the proposed encryption method is secure and reliable enough to be used for communication application.

  1. A new technique for processing airborne gamma ray spectrometry data for mapping low level contaminations

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. E-mail: hka@iau.dtu.dk; Korsbech, U.; Bargholz, K.; Hovgaard, J

    1999-12-01

    A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes {sup 137}Cs at levels often well below 1 kBq/m{sup 2} equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum stability and accurate altitude measurements.

  2. Regional water table (2014) in the Mojave River and Morongo Groundwater Basins, southwestern Mojave Desert, California

    Science.gov (United States)

    Teague, Nick F.; Stamos, Christina L.; House, Sally F.; Clark, Dennis A.

    2016-06-28

    2014 Water TableData for static water levels measured in about 610 wells during March–April 2014 by the U.S. Geological Survey (USGS), the Mojave Water Agency (MWA), and other local water districts were compiled to construct this regional water-table map. This map shows the elevation of the water table and general direction of groundwater movement in and around the Mojave River and Morongo groundwater basins. Water levels recorded by the USGS and MWA staff were measured and compiled according to the procedures described in the Groundwater Technical Procedures of the U.S. Geological Survey (Cunningham and Schalk, 2011). Water-level data submitted by cooperating local water districts were collected by using procedures established by the corresponding agency and were compiled according to the procedures described in the Groundwater Technical Procedures of the U.S. Geological Survey (Cunningham and Schalk, 2011). All data were compared to historical data for qualityassurance purposes. Water-level contours from the 2012 water-level map (Teague and others, 2014) were used as a guide to interpret and shape the 2014 water-level contours in areas where 2014 water-level data were not available; these contours are shown as dashed (approximate) on this water-table map. Water-level data and contours are shown for the Warren subbasin in the Morongo groundwater basin in greater detail on inset A.The water table is the surface at which the fluid pressure in the pores of a porous medium is exactly atmospheric (Freeze and Cherry, 1979). The water table is defined by the level of the water surface in wells that just penetrate the top of the water body (Lohman, 1972). The water-level measurements used for the water-level contour maps are from wells that have more than one perforated interval in the saturated zone of the groundwater basins. Although these wells can have different perforated zones, the measured water levels from the zones were within about 10 feet (ft) and, therefore

  3. Groundwater level monitoring sampling and analysis plan for environmental monitoring in Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-01

    This Sampling and Analysis Plan addresses groundwater level monitoring activities that will be conducted in support of the Environmental Monitoring Plan for Waste Area Grouping (WAG) 6. WAG 6 is a shallow-burial land disposal facility for low-level radioactive waste at the Oak Ridge National Laboratory, a research facility owned by the US Department of Energy and managed by Martin Marietta Energy Systems, Inc. Groundwater level monitoring will be conducted at 129 sites within the WAG. All of the sites will be manually monitored on a semiannual basis. Forty-five of the 128 wells, plus one site in White Oak Lake, will also be equipped with automatic water level monitoring equipment. The 46 sites are divided into three groups. One group will be equipped for continuous monitoring of water level, conductivity, and temperature. The other two groups will be equipped for continuous monitoring of water level only. The equipment will be rotated between the two groups. The data collected from the water level monitoring will be used to support determination of the contaminant flux at WAG 6.

  4. [Comparative analysis of two different methods for risk assessment of groundwater pollution: a case study in Beijing plain].

    Science.gov (United States)

    Wang, Hong-na; He, Jiang-tao; Ma, Wen-jie; Xu, Zhen

    2015-01-01

    Groundwater contamination risk assessment has important meaning to groundwater contamination prevention planning and groundwater exploitation potentiality. Recently, UN assessment system and WP assessment system have become the focuses of international research. In both systems, the assessment framework and indices were drawn from five aspects: intrinsic vulnerability, aquifer storage, groundwater quality, groundwater resource protection zone and contamination load. But, the five factors were built up in different ways. In order to expound the difference between the UN and WP assessment systems, and explain the main reasons, the UN and WP assessment systems were applied to Beijing Plain, China. The maps constructed from the UN and WP risk assessment systems were compared. The results showed that both kinds of groundwater contamination risk assessment maps were in accordance with the actual conditions and were similar in spatial distribution trends. However, there was quite significant different in the coverage area at the same level. It also revealed that during the system construction process, the structural hierarchy, relevant overlaying principles and classification method might have effects on the groundwater contamination risk assessment map. UN assessment system and WP assessment system were both suitable for groundwater contamination risk assessment of the plain, however, their emphasis was different.

  5. Mapping topographic structure in white matter pathways with level set trees.

    Directory of Open Access Journals (Sweden)

    Brian P Kent

    Full Text Available Fiber tractography on diffusion imaging data offers rich potential for describing white matter pathways in the human brain, but characterizing the spatial organization in these large and complex data sets remains a challenge. We show that level set trees--which provide a concise representation of the hierarchical mode structure of probability density functions--offer a statistically-principled framework for visualizing and analyzing topography in fiber streamlines. Using diffusion spectrum imaging data collected on neurologically healthy controls (N = 30, we mapped white matter pathways from the cortex into the striatum using a deterministic tractography algorithm that estimates fiber bundles as dimensionless streamlines. Level set trees were used for interactive exploration of patterns in the endpoint distributions of the mapped fiber pathways and an efficient segmentation of the pathways that had empirical accuracy comparable to standard nonparametric clustering techniques. We show that level set trees can also be generalized to model pseudo-density functions in order to analyze a broader array of data types, including entire fiber streamlines. Finally, resampling methods show the reliability of the level set tree as a descriptive measure of topographic structure, illustrating its potential as a statistical descriptor in brain imaging analysis. These results highlight the broad applicability of level set trees for visualizing and analyzing high-dimensional data like fiber tractography output.

  6. Estimation of spatial distrubition of groundwater level and risky areas of seawater intrusion on the coastal region in Çarşamba Plain, Turkey, using different interpolation methods.

    Science.gov (United States)

    Arslan, Hakan

    2014-08-01

    Groundwater level plays a significant role in coastal plains. Heavy pumping and excessive use of near-coast groundwater can increase the intrusion of seawater into the aquifers. In the present study, groundwater levels were measured at 59 groundwater wells at different times during pre- and post-irrigation seasons (April and September of the year 2012) in Çarşamba Plain, Turkey. To select the best method, two deterministic interpolation methods (inverse distance weighing (IDW) with the weights of 1, 2, and 3 and radial basis function (RBF) with spline with tension (SPT) and completely regularized spline (CRS)) and two stochastic methods (ordinary kriging (OK) with spherical, exponential, and Gaussian variograms) and cokriging (COK)) were compared and then the best interpolation method was used to evaluate the spatial distribution of groundwater levels in different seasons and seasonal changes. A total of nine different techniques were tested. Also, risky areas of seawater intrusion in coastal area were determined using the best methods for two periods. The performance of these interpolation methods is evaluated by using a validation test method. Statistical indices of correlation (R (2)), mean absolute error (MAE), and root-mean-square error (RMSE) were used to select and validate the best methods. Comparisons between predicted and observed values indicated RBF as the optimal method for groundwater level estimation in April and September. When the best method RBF and the worst method IDW were compared, significant differences were observed in the spatial distribution of groundwater. Results of the study also revealed that excessive groundwater withdrawals during the post-irrigation season dropped the groundwater levels up to 2.0 m in some sections. With regard to seawater intrusion, 9,103 ha of land area was determined to be highly risky and risky.

  7. High-resolution monitoring across the soil-groundwater interface - Revealing small-scale hydrochemical patterns with a novel multi-level well

    Science.gov (United States)

    Gassen, Niklas; Griebler, Christian; Stumpp, Christine

    2016-04-01

    Biogeochemical turnover processes in the subsurface are highly variable both in time and space. In order to capture this variability, high resolution monitoring systems are required. Particular in riparian zones the understanding of small-scale biogeochemical processes is of interest, as they are regarded as important buffer zones for nutrients and contaminants with high turnover rates. To date, riparian research has focused on influences of groundwater-surface water interactions on element cycling, but little is known about processes occurring at the interface between the saturated and the unsaturated zone during dynamic flow conditions. Therefore, we developed a new type of high resolution multi-level well (HR-MLW) that has been installed in the riparian zone of the Selke river. This HR-MLW for the first time enables to derive water samples both from the unsaturated and the saturated zone across one vertical profile with a spatial vertical resolution of 0.05 to 0.5 m to a depth of 4 m b.l.s. Water samples from the unsaturated zone are extracted via suction cup sampling. Samples from the saturated zone are withdrawn through glass filters and steel capillaries. Both, ceramic cups and glass filters, are installed along a 1" HDPE piezometer tube. First high resolution hydrochemical profiles revealed a distinct depth-zonation in the riparian alluvial aquifer. A shallow zone beneath the water table carried a signature isotopically and hydrochemically similar to the nearby river, while layers below 1.5 m were influenced by regional groundwater. This zonation showed temporal dynamics related to groundwater table fluctuations and microbial turnover processes. The HR-MLW delivered new insight into mixing and turnover processes between riverwater and groundwater in riparian zones, both in a temporal and spatial dimension. With these new insights, we are able to improve our understanding of dynamic turnover processes at the soil - groundwater interface and of surface

  8. Temporal and spatial dynamical simulation of groundwater characteristics in Minqin Oasis

    Institute of Scientific and Technical Information of China (English)

    XIAO DuNing; LI XiaoYu; SONG DongMei; YANG GuoJing

    2007-01-01

    Application scope of geostatistics has been gradually extended from original geologic field to soil science and ecological field, etc. And its successful application results have been widely demonstrated. But little information is reported as to the direct use of geostatistical method to work out the distribution map of groundwater characteristics. In this paper the semivariogram of geostatistics, in combination with GIS, was used to quantitatively study the spatial variation characteristics of groundwater table depth and mineralization degree and their relation to the landuse changes. F test of the used spherical model reached a very significant level, and the theoretical model can well reflect the spatial structural characteristics of groundwater table depth and mineralization degree and achieve an ideal result. This shows that the application of the method in the dynamical simulation of groundwater is feasible. And this paper also provides useful reference for the application of geostatistics in the study of the dynamical variations of groundwater resources in the oasis.

  9. Temporal and spatial dynamical simulation of groundwater characteristics in Minqin Oasis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Application scope of geostatistics has been gradually extended from original geologic field to soil science and ecological field, etc. and its successful application results have been widely demonstrated. But little information is reported as to the direct use of geostatistical method to work out the distribu- tion map of groundwater characteristics. In this paper the semivariogram of geostatistics, in combina- tion with GIS, was used to quantitatively study the spatial variation characteristics of groundwater table depth and mineralization degree and their relation to the landuse changes. F test of the used spherical model reached a very significant level, and the theoretical model can well reflect the spatial structural characteristics of groundwater table depth and mineralization degree and achieve an ideal result. This shows that the application of the method in the dynamical simulation of groundwater is feasible. And this paper also provides useful reference for the application of geostatistics in the study of the dy- namical variations of groundwater resources in the oasis.

  10. Shallow Groundwater Movement in the Skagit River Delta Area, Skagit County, Washington

    Science.gov (United States)

    Savoca, Mark E.; Johnson, Kenneth H.; Fasser, Elisabeth T.

    2009-01-01

    Shallow groundwater movement in an area between the lower Skagit River and Puget Sound was characterized by the U.S. Geological Survey to assist Skagit County and the Washington State Department of Ecology with the identification of areas where water withdrawals from existing and new wells could adversely affect streamflow in the Skagit River. The shallow groundwater system consists of alluvial, lahar runout, and recessional outwash deposits composed of sand, gravel, and cobbles, with minor lenses of silt and clay. Upland areas are underlain by glacial till and outwash deposits that show evidence of terrestrial and shallow marine depositional environments. Bedrock exposures are limited to a few upland outcrops in the southwestern part of the study area, and consist of metamorphic, sedimentary, and igneous rocks. Water levels were measured in 47 wells on a quarterly basis (August 2007, November 2007, February 2008, and May 2008). Measurements from 34 wells completed in the shallow groundwater system were used to construct groundwater-level and flow-direction maps and perform a linear-regression analysis to estimate the overall, time averaged shallow groundwater-flow direction and gradient. Groundwater flow in the shallow groundwater system generally moves in a southwestward direction away from the Skagit River and toward the Swinomish Channel and Skagit Bay. Local groundwater flow towards the river was inferred during February 2008 in areas west and southwest of Mount Vernon. Water-level altitudes varied seasonally, however, and generally ranged from less than 3 feet (August 2007) in the west to about 15 feet (May 2008) in the east. The time-averaged, shallow groundwater-flow direction derived from regression analysis, 8.5 deg south of west, was similar to flow directions depicted on the quarterly water-level maps. Seasonal changes in groundwater levels in most wells in the Skagit River Delta follow a typical pattern for shallow wells in western Washington. Water

  11. Network-level accident-mapping: Distance based pattern matching using artificial neural network.

    Science.gov (United States)

    Deka, Lipika; Quddus, Mohammed

    2014-04-01

    The objective of an accident-mapping algorithm is to snap traffic accidents onto the correct road segments. Assigning accidents onto the correct segments facilitate to robustly carry out some key analyses in accident research including the identification of accident hot-spots, network-level risk mapping and segment-level accident risk modelling. Existing risk mapping algorithms have some severe limitations: (i) they are not easily 'transferable' as the algorithms are specific to given accident datasets; (ii) they do not perform well in all road-network environments such as in areas of dense road network; and (iii) the methods used do not perform well in addressing inaccuracies inherent in and type of road environment. The purpose of this paper is to develop a new accident mapping algorithm based on the common variables observed in most accident databases (e.g. road name and type, direction of vehicle movement before the accident and recorded accident location). The challenges here are to: (i) develop a method that takes into account uncertainties inherent to the recorded traffic accident data and the underlying digital road network data, (ii) accurately determine the type and proportion of inaccuracies, and (iii) develop a robust algorithm that can be adapted for any accident set and road network of varying complexity. In order to overcome these challenges, a distance based pattern-matching approach is used to identify the correct road segment. This is based on vectors containing feature values that are common in the accident data and the network data. Since each feature does not contribute equally towards the identification of the correct road segments, an ANN approach using the single-layer perceptron is used to assist in "learning" the relative importance of each feature in the distance calculation and hence the correct link identification. The performance of the developed algorithm was evaluated based on a reference accident dataset from the UK confirming that

  12. Physical, chemical, and mineralogical data from surficial deposits, groundwater levels, and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada

    Science.gov (United States)

    Goldstein, Harland L.; Breit, George N.; Yount, James C.; Reynolds, Richard L.; Reheis, Marith C.; Skipp, Gary L.; Fisher, Eric M.; Lamothe, Paul J.

    2011-01-01

    This report presents data and describes the methods used to determine the physical attributes, as well as the chemical and mineralogical composition of surficial deposits; groundwater levels; and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada. The results support studies that examine (1) the interaction between groundwater and the ground surface, and the transport of solutes through the unsaturated zone; (2) the potential for the accumulation of metals and metalloids in surface crusts; (3) emission of dust from metal-rich salt crust; and (4) the effects of metal-rich dusts on human and ecosystem health. The evaporation of shallow (salt in the subsurface and (or) the formation of salt crusts at the ground surface. Ground-surface characteristics such as hardness, electrical conductivity, and mineralogy depend on the types and forms of these salt crusts. In the study area, salt crusts range from hard and bedded to soft and loose (Reynolds and others, 2009). Depending on various factors such as the depth and composition of groundwater and sediment characteristics of the unsaturated zone, salt crusts may accumulate relatively high contents of trace elements. Soft, loose salt crusts are highly vulnerable to wind erosion and transport. These vulnerable crusts, which may contain high contents of potentially toxic trace elements, can travel as atmospheric dust and affect human and ecosystem health at local to regional scales.

  13. Groundwater data network interoperability

    Science.gov (United States)

    Brodaric, Boyan; Booth, Nathaniel; Boisvert, Eric; Lucido, Jessica M.

    2016-01-01

    Water data networks are increasingly being integrated to answer complex scientific questions that often span large geographical areas and cross political borders. Data heterogeneity is a major obstacle that impedes interoperability within and between such networks. It is resolved here for groundwater data at five levels of interoperability, within a Spatial Data Infrastructure architecture. The result is a pair of distinct national groundwater data networks for the United States and Canada, and a combined data network in which they are interoperable. This combined data network enables, for the first time, transparent public access to harmonized groundwater data from both sides of the shared international border.

  14. Effect of diversified crop rotations on groundwater levels and crop water productivity in the North China Plain

    Science.gov (United States)

    Yang, Xiaolin; Chen, Yuanquan; Pacenka, Steven; Gao, Wangsheng; Ma, Li; Wang, Guangya; Yan, Peng; Sui, Peng; Steenhuis, Tammo S.

    2015-03-01

    Water shortage is the major bottleneck that limits sustainable yield of agriculture in the North China Plain. Due to the over-exploitation of groundwater for irrigating the winter wheat-summer maize double cropping systems, a groundwater crisis is becoming increasingly serious. To help identify more efficient and sustainable utilization of the limited water resources, the water consumption and water use efficiency of five irrigated cropping systems were calculated and the effect of cropping systems on groundwater table changes was estimated based on a long term field experiment from 2003 to 2013 in the North China Plain interpreted using a soil-water-balance model. The five cropping systems included sweet potato → cotton → sweet potato → winter wheat-summer maize (SpCSpWS, 4-year cycle), ryegrass-cotton → peanuts → winter wheat-summer maize (RCPWS, 3-year cycle), peanuts → winter wheat-summer maize (PWS, 2-year cycle), winter wheat-summer maize (WS, 1-year cycle), and continuous cotton (Cont C). The five cropping systems had a wide range of annual average actual evapotranspiration (ETa): Cont C (533 mm/year) RCPWS (0.7 m/year) > PWS (0.6 m/year) > SPCSPWS and Cont C (0.4 m/year). The annual average economic output water use efficiency (WUEe) increased in the order SpCSpWS (11.6 yuan ¥ m-3) > RCPWS (9.0 ¥ m-3) > PWS (7.3 ¥ m-3) > WS (6.8 ¥ m-3) > Cont C (5.6 ¥ m-3) from 2003 to 2013. Results strongly suggest that diversifying crop rotations could play a critically important role in mitigating the over-exploitation of the groundwater, while ensuring the food security or boosting the income of farmers in the North China Plain.

  15. Mapping Urban Impervious Surface by Fusing Optical and SAR Data at the Decision Level

    Directory of Open Access Journals (Sweden)

    Zhenfeng Shao

    2016-11-01

    Full Text Available The proliferation of impervious surfaces results in a series of environmental issues, such as the decrease of vegetated areas and the aggravation of the urban heat island effects. The mapping of impervious surface and its spatial distributions is of significance for the ecological study of urban environment. Currently, the integration of optical and synthetic aperture radar (SAR data has shown advantages in accurately characterizing impervious surface. However, the fusion mainly occurs at the pixel and feature levels which are subject to influences of data noises and feature selections, respectively. In this paper, an innovative and effective method was developed to extract urban impervious surface by synergistically utilizing optical and SAR images at the decision level. The objective of this paper was to obtain an accurate urban impervious surface map based on the random forest classifier and the evidence theory and to provide a detailed uncertainty analysis accompanying the fused impervious surface maps. In this study, both the GaoFen (GF-1 and Sentinel-1A imagery were first used as independent data sources for mapping urban impervious surfaces. Then additional spectral features and texture features were extracted and integrated with the original GF-1 and Sentinel-1A images in generating impervious surfaces. Finally, based on the Dempster-Shafer (D-S theory, impervious surfaces were produced by fusing the previously estimated impervious surfaces from different datasets at the decision level. Results showed that impervious surfaces estimated from the combined use of original images and features yielded a higher accuracy than those from the original optical or SAR data. Further validations suggested that optical data was better than SAR data in separating impervious surfaces from non-impervious surfaces. The fused impervious surfaces at the decision level had a higher overall accuracy than those produced independently by optical or SAR data. It

  16. Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, January 2011

    Science.gov (United States)

    Hansen, Cristi V.

    2011-01-01

    The Equus Beds aquifer in southwestern Harvey County and northwestern Sedgwick County was developed to supply water to the city of Wichita and for irrigation in south-central Kansas. Water-level and storage-volume decreases that began with the development of the aquifer in the 1940s reached record to near-record lows in January 1993. Since 1993, the aquifer has been experiencing higher water levels and a partial recovery of storage volume. Potentiometric maps of the shallow and deep layers of the map show flow in both aquifer layers is generally from west to east. Water-level altitudes in the shallow aquifer layer ranged from a high of about 1,470 feet in the northwest corner of the study area to low of about 1,330 feet in the southeast corner of the study area; water-level altitudes in the deep aquifer layer ranged from a high of about 1,440 feet on the west edge of the study area to a low of about 1,330 feet in the southeast corner of the study area. In the northwest part of the study area, water-levels can be up to 50 feet higher in the shallow layer than in the deep layer of the Equus Beds aquifer. Measured water-level changes for August 1940 to January 2011 ranged from a decline of 16.52 feet to a rise of 2.22 feet. The change in storage volume from August 1940 to January 2011 was a decrease of about 104,000 acre-feet. This volume represents a recovery of about 151,000 acre-feet, or about 59 percent of the storage volume previously lost between August 1940 and January 1993. It also represents a recovery of about 63,000 acre-feet, or about 38 percent of the storage volume lost between August 1940 and January 2007. Major factors in these storage-volume recoveries are increased recharge from greater-than-normal precipitation and planned decreases in city pumpage that are part of Wichita's Integrated Local Water Supply Plan; however, part of the recovery may be because city and irrigation pumpage probably decreased in response to greater-than-normal precipitation

  17. Modeling of Morelia Fault Earthquake (Mw=5.4) source fault parameters using the coseismic ground deformation and groundwater level changes data

    Science.gov (United States)

    Sarychikhina, O.; Glowacka, E.; Mellors, R. J.; Vázquez, R.

    2009-12-01

    On 24 May 2006 at 04:20 (UTC) a moderate-size (Mw=5.4) earthquake struck the Mexicali Valley, Baja California, México, roughly 30 km to the southeast of the city of Mexicali, in the vicinity of the Cerro Prieto Geothermal Field (CPGF). The earthquake occurred on the Morelia fault, one of the east-dipping normal faults in the Mexicali Valley. Locally, this earthquake was strongly felt and caused minor damage. The event created 5 km of surface rupture and down-dip displacements of up to 25-30 cm were measured at some places along this surface rupture. Associated deformation was measured by vertical crackmeter, leveling profile, and Differential Synthetic Aperture Radar Interferometry (D-InSAR). A coseismic step-like groundwater level change was detected at 7 wells. The Mw=5.4 Morelia Fault earthquake had significant scientific interest, first, because of surprisingly strong effects for an earthquake of such size; second, the variability of coseismic effects data from different ground-based and space-based techniques which allows to the better constrain of the source fault parameters. Source parameters for the earthquake were estimated using forward modeling of both surface deformation data and static volume strain change (inferred from coseismic changes in groundwater level). All ground deformation data was corrected by anthropogenic component caused by the geothermal fluid exploitation in the CPGF. Modeling was based on finite rectangular fault embedded in an elastic media. The preferred fault model has a strike, rake, and dip of (48°, -89°, 45°) and has a length of 5.2 km, width of 6.7 km, and 34 cm of uniform slip. The geodetic moment, based on the modeled fault parameters, is 1.18E+17 Nm. The model matches the observed surface deformation, expected groundwater level changes, and teleseismic moment reasonably well and explains in part why the earthquake was so strongly felt in the area.

  18. Groundwater Modelling For Recharge Estimation Using Satellite Based Evapotranspiration

    Science.gov (United States)

    Soheili, Mahmoud; (Tom) Rientjes, T. H. M.; (Christiaan) van der Tol, C.

    2017-04-01

    Groundwater movement is influenced by several factors and processes in the hydrological cycle, from which, recharge is of high relevance. Since the amount of aquifer extractable water directly relates to the recharge amount, estimation of recharge is a perquisite of groundwater resources management. Recharge is highly affected by water loss mechanisms the major of which is actual evapotranspiration (ETa). It is, therefore, essential to have detailed assessment of ETa impact on groundwater recharge. The objective of this study was to evaluate how recharge was affected when satellite-based evapotranspiration was used instead of in-situ based ETa in the Salland area, the Netherlands. The Methodology for Interactive Planning for Water Management (MIPWA) model setup which includes a groundwater model for the northern part of the Netherlands was used for recharge estimation. The Surface Energy Balance Algorithm for Land (SEBAL) based actual evapotranspiration maps from Waterschap Groot Salland were also used. Comparison of SEBAL based ETa estimates with in-situ abased estimates in the Netherlands showed that these SEBAL estimates were not reliable. As such results could not serve for calibrating root zone parameters in the CAPSIM model. The annual cumulative ETa map produced by the model showed that the maximum amount of evapotranspiration occurs in mixed forest areas in the northeast and a portion of central parts. Estimates ranged from 579 mm to a minimum of 0 mm in the highest elevated areas with woody vegetation in the southeast of the region. Variations in mean seasonal hydraulic head and groundwater level for each layer showed that the hydraulic gradient follows elevation in the Salland area from southeast (maximum) to northwest (minimum) of the region which depicts the groundwater flow direction. The mean seasonal water balance in CAPSIM part was evaluated to represent recharge estimation in the first layer. The highest recharge estimated flux was for autumn

  19. Quantifying Urban Natural Gas Leaks from Street-level Methane Mapping: Measurements and Uncertainty

    Science.gov (United States)

    von Fischer, J. C.; Ham, J. M.; Griebenow, C.; Schumacher, R. S.; Salo, J.

    2013-12-01

    Leaks from the natural gas pipeline system are a significant source of anthropogenic methane in urban settings. Detecting and repairing these leaks will reduce the energy and carbon footprints of our cities. Gas leaks can be detected from spikes in street-level methane concentrations measured by analyzers deployed on vehicles. While a spike in methane concentration indicates a leak, an algorithm (e.g., inverse model) must be used to estimate the size of the leak (i.e., flux) from concentration data and supporting meteorological information. Unfortunately, this drive-by approach to leak quantification is confounded by the complexity of urban roughness, changing weather conditions, and other incidental factors (e.g., traffic, vehicle speed, etc.). Furthermore, the vehicle might only pass through the plume one to three times during routine mapping. The objective of this study was to conduct controlled release experiments to better quantify the relationship between mobile methane concentration measurements and the size and location of the emission source (e.g., pipeline leakage) in an urban environment. A portable system was developed that could release methane at known rates between 10 and 40 LPM while maintaining concentrations below the lower explosive limit. A mapping vehicle was configured with fast response methane analyzers, GPS, and meteorological instruments. Portable air-sampling tripods were fabricated that could be deployed at defined distances downwind from the release point and automatically-triggered to collect grab samples. The experimental protocol was as follows: (1) identify an appropriate release point within a city, (2) release methane at a known rate, (3) measure downwind street-level concentrations with the vehicle by making multiple passes through the plume, and (4) collect supporting concentration and meteorological data with the static tripod samplers deployed in the plume. Controlled release studies were performed at multiple locations and

  20. Developing a high resolution groundwater model for Indonesia

    Science.gov (United States)

    Sutanudjaja, E.; de Graaf, I. E.; Alberti, K.; Van Beek, L. P.; Bierkens, M. F.

    2013-12-01

    Groundwater is important in many parts of Indonesia. It serves as a primary source of drinking water and industrial activities. During times of drought, it sustains water flows in streams, rivers, lakes and wetlands, and thus support ecosystem habitat and biodiversity, as well as preventing hazardous forest fire. Besides its importance, groundwater is known as a vulnerable resource as unsustainable groundwater exploitation and management occurs in many areas of the country. Therefore, in order to ensure sustainable management of groundwater resources, monitoring and predicting groundwater changes in Indonesia are imperative. However, large-extent groundwater models to assess these changes on a regional scale are almost non-existent and are hampered by the strong topographical and lithological transitions that characterize Indonesia. In this study, we built an 1 km resolution of steady-state groundwater model for the entire Indonesian archipelago (total inland area: about 2 million km2). Here we adopted the approach of Sutanudjaja et al. (2011) in order to make a MODFLOW (McDonald and Harbaugh, 1988) groundwater model by using only global datasets. Aquifer schematization and properties of the groundwater model were developed from available global lithological map (e.g. Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moorsdorf, 2012). We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the long term net groundwater recharge and average surface water levels derived from routed channel discharge. Results are promising. The MODFLOW model can converge with realistic aquifer properties (i.e. transmissivities) and produce reasonable groundwater head spatial distribution that reflects the positions of major groundwater bodies and surface water bodies in the country. For this session, we aim to demonstrate and discuss the results and the prospects of this modeling study. References: D

  1. Integration of In Situ Radon Modeling with High Resolution Aerial Remote Sensing for Mapping and Quantifying Local to Regional Flow and Transport of Submarine Groundwater Discharge from Coastal Aquifers

    Science.gov (United States)

    Glenn, C. R.; Kennedy, J. J.; Dulaiova, H.; Kelly, J. L.; Lucey, P. G.; Lee, E.; Fackrell, J.

    2015-12-01

    Submarine groundwater discharge (SGD) is a principal conduit for huge volumes of fresh groundwater loss and is a key transport mechanism for nutrient and contaminant pollution to coastal zones worldwide. However, the volumes and spatially and temporally variable nature of SGD is poorly known and requires rapid and high-resolution data acquisition at the scales in which it is commonly observed. Airborne thermal infrared (TIR) remote sensing, using high-altitude manned aircraft and low-altitude remote-controlled unmanned aerial vehicles (UAVs or "Drones") are uniquely qualified for this task, and applicable wherever 0.1°C temperature contrasts exist between discharging and receiving waters. We report on the use of these technologies in combination with in situ radon model studies of SGD volume and nutrient flux from three of the largest Hawaiian Islands. High altitude manned aircraft results produce regional (~300m wide x 100s km coastline) 0.5 to 3.2 m-resolution sea-surface temperature maps accurate to 0.7°C that show point-source and diffuse flow in exquisite detail. Using UAVs offers cost-effective advantages of higher spatial and temporal resolution and instantaneous deployments that can be coordinated simultaneously with any ground-based effort. We demonstrate how TIR-mapped groundwater discharge plume areas may be linearly and highly correlated to in situ groundwater fluxes. We also illustrate how in situ nutrient data may be incorporated into infrared imagery to produce nutrient distribution maps of regional worth. These results illustrate the potential for volumetric quantification and up-scaling of small- to regional-scale SGD. These methodologies provide a tremendous advantage for identifying and differentiating spring-fed, point-sourced, and/or diffuse groundwater discharge into oceans, estuaries, and streams. The integrative techniques are also important precursors for developing best-use and cost-effective strategies for otherwise time-consuming in

  2. Evaluation of levels of antibiotic resistance in groundwater-derived E. coli isolates in the Midwest of Ireland and elucidation of potential predictors of resistance

    Science.gov (United States)

    O'Dwyer, Jean; Hynds, Paul; Pot, Matthieu; Adley, Catherine C.; Ryan, Michael P.

    2017-02-01

    Antibiotic-resistant (pathogenic and non-pathogenic) organisms and genes are now acknowledged as significant emerging aquatic contaminants with potentially adverse human and ecological health impacts, and thus require monitoring. This study is the first to investigate levels of resistance among Irish groundwater (private wells) samples; Escherichia coli isolates were examined against a panel of commonly prescribed human and veterinary therapeutic antibiotics, followed by determination of the causative factors of resistance. Overall, 42 confirmed E. coli isolates were recovered from a groundwater-sampling cohort. Resistance to the human panel of antibiotics was moderate; nine (21.4%) E. coli isolates demonstrated resistance to one or more human antibiotics. Conversely, extremely high levels of resistance to veterinary antibiotics were found, with all isolates presenting resistance to one or more veterinary antibiotics. Particularly high levels of resistance (93%) were found with respect to the aminoglycoside class of antibiotics. Results of statistical analysis indicate a significant association between the presence of human (multiple) antibiotic resistance (p = 0.002-0.011) and both septic tank density and the presence of vulnerable sub-populations (<5 years). For the veterinary antibiotics, results point to a significant relationship (p = <0.001) between livestock (cattle) density and the prevalence of multiple antibiotic resistant E. coli. Groundwater continues to be an important resource in Ireland, particularly in rural areas; thus, results of this preliminary study offer a valuable insight into the prevalence of antibiotic resistance in the hydrogeological environment and establish a need for further research with a larger geological diversity.

  3. Updated study reporting levels (SRLs) for trace-element data collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Priority Basin Project, October 2009-March 2013

    Science.gov (United States)

    Davis, Tracy A.; Olsen, Lisa D.; Fram, Miranda S.; Belitz, Kenneth

    2014-01-01

    Groundwater samples have been collected in California as part of statewide investigations of groundwater quality conducted by the U.S. Geological Survey for the Groundwater Ambient Monitoring and Assessment (GAMA) Priority Basin Project (PBP). The GAMA-PBP is being conducted in cooperation with the California State Water Resources Control Board to assess and monitor the quality of groundwater resources used for drinking-water supply and to improve public knowledge of groundwater quality in California. Quality-control samples (source-solution blanks, equipment blanks, and field blanks) were collected in order to ensure the quality of the groundwater sample results. Olsen and others (2010) previously determined study reporting levels (SRLs) for trace-element results based primarily on field blanks collected in California from May 2004 through January 2008. SRLs are raised reporting levels used to reduce the likelihood of reporting false detections attributable to contamination bias. The purpose of this report is to identify any changes in the frequency and concentrations of detections in field blanks since the last evaluation and update the SRLs for more recent data accordingly. Constituents analyzed were aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), silver (Ag), strontium (Sr), thallium (Tl), tungsten (W), uranium (U), vanadium (V), and zinc (Zn). Data from 179 field blanks and equipment blanks collected from March 2006 through March 2013 by the GAMA-PBP indicated that for trace elements that had a change in detection frequency and concentration since the previous review, the shift occurred near October 2009, in conjunction with a change in the capsule filters used by the study. Results for 89 field blanks and equipment blanks collected from October 2009 through March 2013 were

  4. Movement of a tritium plume in shallow groundwater at a legacy low-level radioactive waste disposal site in eastern Australia.

    Science.gov (United States)

    Hughes, C E; Cendón, D I; Harrison, J J; Hankin, S I; Johansen, M P; Payne, T E; Vine, M; Collins, R N; Hoffmann, E L; Loosz, T

    2011-10-01

    Between 1960 and 1968 low-level radioactive waste was buried in a series of shallow trenches near the Lucas Heights facility, south of Sydney, Australia. Groundwater monitoring carried out since the mid 1970s indicates that with the exception of tritium, no radioactivity above typical background levels has been detected outside the immediate vicinity of the trenches. The maximum tritium level detected in ground water was 390 kBq/L and the median value was 5400 Bq/L, decay corrected to the time of disposal. Since 1968, a plume of tritiated water has migrated from the disposal trenches and extends at least 100 m from the source area. Tritium in rainfall is negligible, however leachate from an adjacent and fill represents a significant additional tritium source. Study data indicate variation in concentration levels and plume distribution in response to wet and dry climatic periods and have been used to determine pathways for tritium migration through the subsurface.

  5. Groundwater Infiltration Potential (GWIP) as an aid to determining the cause of dilution of waste water

    Science.gov (United States)

    Dirckx, Geert; Van Daele, Sofie; Hellinck, Nathan

    2016-11-01

    Groundwater infiltration through leaking sewers represents a considerable fraction of the total amount of wastewater dilution. In search for an easy-to-determine yet acceptably accurate estimation of the likelihood of groundwater infiltration into leaking sewers, the parameter 'groundwater infiltration potential' or shortly GWIP was defined. GWIP expresses the extent to which groundwater infiltration could - in contrast to the inflow of surface water - be a cause of dilution of sewage. The GWIP is determined by a comparison between the elevation of the groundwater table with the position of the sewer conduits per geo-spatial aggregation level (GAL). This first order analysis compares sets of three representative figures of the groundwater table's elevation, i.e. the minimum, the maximum and the average level with sets of two representative values of the pipes' positions, i.e. average invert and soffit levels. A GWIP map can be set-up indicating per GAL a GWIP score that represents a generic evaluation of the common (i.e. most occurring or representative) situation regarding the presence of the groundwater table versus the elevations of the sewer system. In this way the GWIP map can assist in the determination of the overall most likely origin - either surface water or groundwater - of dilution per GAL. Eventually this facilitates strategic decisions regarding the search for particular locations of dilution, and subsequently for the selection of specific remediation measures. The methodology is developed on a local scale of Flanders, Belgium but is generic and therefore applicable to any other region provided that information on the elevation of the sewer system and groundwater table is available.

  6. Tracing groundwater with low-level detections of halogenated VOCs in a fractured carbonate-rock aquifer, Leetown Science Center, West Virginia, USA

    Science.gov (United States)

    Plummer, L. Niel; Sibrell, Philip L.; Casile, Gerolamo C.; Busenberg, Eurybiades; Hunt, Andrew G.; Schlosser, Peter

    2013-01-01

    Measurements of low-level concentrations of halogenated volatile organic compounds (VOCs) and estimates of groundwater age interpreted from 3H/3He and SF6 data have led to an improved understanding of groundwater flow, water sources, and transit times in a karstic, fractured, carbonate-rock aquifer at the Leetown Science Center (LSC), West Virginia. The sum of the concentrations of a set of 16 predominant halogenated VOCs (TDVOC) determined by gas chromatography with electron-capture detector (GC–ECD) exceeded that possible for air–water equilibrium in 34 of the 47 samples (median TDVOC of 24,800 pg kg−1), indicating that nearly all the water sampled in the vicinity of the LSC has been affected by addition of halogenated VOCs from non-atmospheric source(s). Leakage from a landfill that was closed and sealed nearly 20 a prior to sampling was recognized and traced to areas east of the LSC using low-level detection of tetrachloroethene (PCE), methyl chloride (MeCl), methyl chloroform (MC), dichlorodifluoromethane (CFC-12), and cis-1,2-dichloroethene (cis-1,2-DCE). Chloroform (CHLF) was the predominant VOC in water from domestic wells surrounding the LSC, and was elevated in groundwater in and near the Fish Health Laboratory at the LSC, where a leak of chlorinated water occurred prior to 2006. The low-level concentrations of halogenated VOCs did not exceed human or aquatic-life health criteria, and were useful in providing an awareness of the intrinsic susceptibility of the fractured karstic groundwater system at the LSC to non-atmospheric anthropogenic inputs. The 3H/3He groundwater ages of spring discharge from the carbonate rocks showed transient behavior, with ages averaging about 2 a in 2004 following a wet climatic period (2003–2004), and ages in the range of 4–7 a in periods of more average precipitation (2008–2009). The SF6 and CFC-12 data indicate older water (model ages of 10s of years or more) in the low-permeability shale of the Martinsburg

  7. Application of Fuzzy Logic Inference System, Interval Numbers and Mapping Operator for Determination of Risk Level

    Directory of Open Access Journals (Sweden)

    Mohsen Omidvar

    2015-12-01

    Full Text Available Background & objective: Due to the features such as intuitive graphical appearance, ease of perception and straightforward applicability, risk matrix has become as one of the most used risk assessment tools. On the other hand, features such as the lack of precision in the classification of risk index, as well as subjective computational process, has limited its use. In order to solve this problem, in the current study we used fuzzy logic inference systems and mathematical operators (interval numbers and mapping operator. Methods: In this study, first 10 risk scenarios in the excavation and piping process were selected, then the outcome of the risk assessment were studied using four types of matrix including traditional (ORM, displaced cells (RCM , extended (ERM and fuzzy (FRM risk matrixes. Results: The results showed that the use of FRM and ERM matrix have prority, due to the high level of " Risk Tie Density" (RTD and "Risk Level Density" (RLD in the ORM and RCM matrix, as well as more accurate results presented in FRM and ERM, in risk assessment. While, FRM matrix provides more reliable results due to the application of fuzzy membership functions. Conclusion: Using new mathematical issues such as fuzzy sets and arithmetic and mapping operators for risk assessment could improve the accuracy of risk matrix and increase the reliability of the risk assessment results, when the accurate data are not available, or its data are avaliable in a limit range.

  8. Correlation between geology and radon levels in groundwater, soil and indoor air in Bhilangana Valley, Garhwal Himalaya, India

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, V.M. [Wadia Inst. of Himalayan Geology, Dehra Dun (India); Ramola, R.C. [Dept. of Physics, H.N.B. Garhwal Univ. Campus, Tehri Garhwal (India)

    1997-11-01

    Radon concentrations were measured in soil, air and groundwater in Bhilangana Valley, Garhwal Himalaya, India by using an LR-115 plastic track detector and radon emanometer. Radon concentrations were found to vary from 1 KBq/m{sup 3} to 57 KBq/m{sup 3} in soil, 5 Bq/l to 887 Bq/l in water and 95 Bq/m{sup 3} to 208 Bq/m{sup 3} in air. The recorded values are quite high due to associated uranium mineralization in the area. Radon concentration was also found to depend on the tectonic structure and geology of the area. (orig.)

  9. Statistical analysis of lake levels and field study of groundwater and surface-water exchanges in the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015: Chapter A of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    Science.gov (United States)

    Jones, Perry M.; Trost, Jared J.; Diekoff, Aliesha L.; Rosenberry, Donald O.; White, Eric A.; Erickson, Melinda L.; Morel, Daniel L.; Heck, Jessica M.

    2016-10-19

    Water levels declined from 2003 to 2011 in many lakes in Ramsey and Washington Counties in the northeast Twin Cities Metropolitan Area, Minnesota; however, water levels in other northeast Twin Cities Metropolitan Area lakes increased during the same period. Groundwater and surface-water exchanges can be important in determining lake levels where these exchanges are an important component of the water budget of a lake. An understanding of groundwater and surface-water exchanges in the northeast Twin Cities Metropolitan Area has been limited by the lack of hydrologic data. The U.S. Geological Survey, in cooperation with the Metropolitan Council and Minnesota Department of Health, completed a field and statistical study assessing lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes. This report documents the analysis of collected hydrologic, water-quality, and geophysical data; and existing hydrologic and geologic data to (1) assess the effect of physical setting and climate on lake-level fluctuations of selected lakes, (2) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (3) estimate general ages for waters extracted from the wells, and (4) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake. Statistical analyses of lake levels during short-term (2002–10) and long-term (1925–2014) periods were completed to help understand lake-level changes across the northeast Twin Cities Metropolitan Area. Comparison of 2002–10 lake levels to several landscape and geologic characteristics explained variability in lake-level changes for 96 northeast Twin Cities Metropolitan Area lakes. Application of several statistical methods determined that (1) closed-basin lakes (without an active outlet) had larger lake-level declines than flow-through lakes with an outlet; (2

  10. Status of groundwater levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, July 2011

    Science.gov (United States)

    Hansen, Cristi V.

    2012-01-01

    The part of the Equus Beds aquifer in southwestern Harvey County and northwestern Sedgwick County was developed to supply water to the city of Wichita and for irrigation in south-central Kansas. The 165 square-mile study area represents about 12 percent of the 1,400 square-mile Equus Beds aquifer and accounts for about one-third of the withdrawals from the aquifer. Water-level and storage-volume decreases that began with the development of the aquifer in the 1940s reached record to near-record lows in January 1993. Since 1993, generally higher water levels and partial storage-volume recoveries have been recorded in the aquifer. Potentiometric maps of the shallow and deep layers of the aquifer show flow in both aquifer layers is generally from west to east. The July 2011 water-level altitudes in the shallow aquifer layer ranged from a high of about 1,470 feet in the northwest corner of the study area to a low of about 1,330 feet in the southeast corner of the study area; water-level altitudes in the deep aquifer layer ranged from a high of about 1,445 feet on the west edge of the study area to a low of about 1,340 feet in the southeast corner of the study area. In the northwest part of the study area, water-levels can be more than 60 feet higher in the shallow layer than in the deep layer of the Equus Beds aquifer. Measured water-level changes for August 1940 to July 2011 ranged from a decline of 43.22 feet to a decline of 0.17 feet and averaged 12.45 feet. The largest August 1940 to July 2011 water-level changes of 30 feet or more occurred in the northern part of the study area centered about 2 and 4 miles east of Burrton, Kansas. The change in storage volume from August 1940 to July 2011 in the study area was a decrease of about 209,000 acre-feet. This volume represents a recovery of about 46,000 acre-feet, or only about 18 percent of the storage volume previously lost between August 1940 and January 1993. The largest post-1993 storage-volume recovery to date in

  11. Mapping critical levels/loads for the Slovak Republic. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Zavodsky, D.; Babiakova, G.; Mitosinkova, M. [and others

    1996-08-01

    As a part of the Agreement on Environmental Cooperation between Norway and Slovakia a project ``Mapping Critical Levels/Loads for Slovakia`` was established. This report presents the final project results. Critical loads for forest, surface and ground waters and their exceedances were calculated by means of the steady-state mass balance model PROFILE for soils, and the steady-state water chemistry method for waters. A grid distance of 10 km was used. Because the sulphur deposition has been decreasing, the exceedances of critical load of acidity and critical sulphur deposition of forest soils have decreased from 1990 to 1995. Practically no acidity exceedances for surface water or ground water were found in 1995. The critical level of forest ozone was exceeded all over Slovakia. In the Tatra mountains the exceedance was over 25000 ppb.h. 23 refs., 3 figs., 3 tabs.

  12. Water quality analysis of groundwater in crystalline basement rocks, Northern Ghana

    Science.gov (United States)

    Anku, Y.S.; Banoeng-Yakubo, B.; Asiedu, D.K.; Yidana, S.M.

    2009-01-01

    Hydrochemical data are presented for groundwater samples, collected from fractured aquifers in parts of northern Ghana. The data was collected to assess the groundwater suitability for domestic and agricultural use. Results of the study reveal that the pH of the groundwater in the area is slightly acidic to slightly alkaline. The electrical conductivity values, total dissolved solids (TDS) values and calcium, magnesium and sodium concentrations in the groundwater are generally below the limit set by the WHO for potable water supply. On the basis of activity diagrams, groundwater from the fractured aquifers appears to be stable within the montmorillonite field, suggesting weathering of silicate minerals. An inverse distance weighting interpolator with a power of 2 was applied to the data points to produce prediction maps for nitrate and fluoride. The distribution maps show the presence of high nitrate concentrations (50-194??mg/l) in some of the boreholes in the western part of the study area indicating anthropogenic impact on the groundwater. Elevated fluoride level (1.5-4??mg/l), higher than the WHO allowable fluoride concentration of 1.5, is recorded in the groundwater underlying the northeastern part of the study area, more specifically Bongo and its surrounding communities of the Upper East region. Results of this study suggest that groundwater from the fractured aquifers in the area exhibit low sodicity-low salinity (S1-C1), low sodicity-medium salinity (S1-C2) characteristics [United States Salinity Laboratory (USSL) classification scheme]. All data points from this study plot within the 'Excellent to good' category on a Wilcox diagram. Groundwater in this area thus appears to provide irrigation water of excellent quality. The hydrochemical results indicate that, although nitrate and fluoride concentrations in some boreholes are high, the groundwater in the study area, based on the parameters analyzed, is chemically potable and suitable for domestic and

  13. Water quality analysis of groundwater in crystalline basement rocks, Northern Ghana

    Science.gov (United States)

    Anku, Yvonne S.; Banoeng-Yakubo, Bruce; Asiedu, Daniel K.; Yidana, Sandow M.

    2009-09-01

    Hydrochemical data are presented for groundwater samples, collected from fractured aquifers in parts of northern Ghana. The data was collected to assess the groundwater suitability for domestic and agricultural use. Results of the study reveal that the pH of the groundwater in the area is slightly acidic to slightly alkaline. The electrical conductivity values, total dissolved solids (TDS) values and calcium, magnesium and sodium concentrations in the groundwater are generally below the limit set by the WHO for potable water supply. On the basis of activity diagrams, groundwater from the fractured aquifers appears to be stable within the montmorillonite field, suggesting weathering of silicate minerals. An inverse distance weighting interpolator with a power of 2 was applied to the data points to produce prediction maps for nitrate and fluoride. The distribution maps show the presence of high nitrate concentrations (50-194 mg/l) in some of the boreholes in the western part of the study area indicating anthropogenic impact on the groundwater. Elevated fluoride level (1.5-4 mg/l), higher than the WHO allowable fluoride concentration of 1.5, is recorded in the groundwater underlying the northeastern part of the study area, more specifically Bongo and its surrounding communities of the Upper East region. Results of this study suggest that groundwater from the fractured aquifers in the area exhibit low sodicity-low salinity (S1-C1), low sodicity-medium salinity (S1-C2) characteristics [United States Salinity Laboratory (USSL) classification scheme]. All data points from this study plot within the ‘Excellent to good’ category on a Wilcox diagram. Groundwater in this area thus appears to provide irrigation water of excellent quality. The hydrochemical results indicate that, although nitrate and fluoride concentrations in some boreholes are high, the groundwater in the study area, based on the parameters analyzed, is chemically potable and suitable for domestic and

  14. Assessment of intrinsic vulnerability of an alluvial aquifer under anthropogenic pressure: cross comparison of 4 index-based groundwater vulnerability mapping models within the Biguglia lagoon watershed (Corsica, France).

    Science.gov (United States)

    Jaunat, Jessy; Huneau, Frédéric; Garel, Emilie; Devos, Alain; Lejeune, Olivier

    2016-04-01

    KEYWORDS: Alluvial aquifer, Vulnerability mapping, Index-based methods, DRASTIC, SINTACS, SI, GOD The geographical position of the Biguglia lagoon watershed south of the Bastia city (80 000 inhabitants), lead to a highly vulnerable hydrosystem setting. This littoral plain is the unique territory available for the urbanisation and for the agriculture activities (cattle breeding). All the activities developed are likely to have a qualitative impact on water infiltration and therefore on groundwater, which is in hydraulic connection with the lagoon system. Beyond this ecological issue, groundwater of this watershed is intensively used as drinking water supply. It appears essential to control the long-term groundwater quality of the Biguglia plain which is the major economic zone of Corsica. Achievement of this issue requires the identification of the areas where the alluvial aquifer is mostly vulnerable to anthropogenic activities. The results given by 4 of the most popular index-based vulnerability mapping methods (DRASTIC, SI, SINTACS and GOD) are compared. The water table, net recharge, aquifer and soils properties, topography, vadose zone and land uses have been precisely mapped and numerically translated in GIS with a 25m precision. 4 final maps were finally compiled according to the weighting factors of each methods. Hydrochemical investigations were also carried out on 30 sampling points (major ions and anthropogenic tracers) to evaluate the effect of anthropogenic activities on groundwater quality and also to validate the results of the vulnerability mapping. A comparison between the parametric models shows a significant agreement between the DRASTIC, SINTACS and SI results (2% to 5% of the total area in very low vulnerability class, 10% to 13% in low vulnerability, 16% to 23% in medium vulnerability, 31% to 53% in high vulnerability and 14% to 23% in very high vulnerability). The two first methods are quite similar, which explains the proximity of the

  15. AN ITERATIVE PIXEL-LEVEL IMAGE MATCHING METHOD FOR MARS MAPPING USING APPROXIMATE ORTHOPHOTOS

    Directory of Open Access Journals (Sweden)

    X. Geng

    2017-07-01

    Full Text Available Mars mapping is essential to the scientific research of the red planet. The special terrain characteristics of Martian surface can be used to develop the targeted image matching method. In this paper, in order to generate high resolution Mars DEM, a pixel-level image matching method for Mars orbital pushbroom images is proposed. The main strategies of our method include: (1 image matching on approximate orthophotos; (2 estimating approximate value of conjugate points by using ground point coordinates of orthophotos; (3 hierarchical image matching; (4 generating DEM and approximate orthophotos at each pyramid level; (5 fast transformation from ground points to image points for pushbroom images. The derived DEM at each pyramid level is used as reference data for the generation of approximate orthophotos at the next pyramid level. With iterative processing, the generated DEM becomes more and more accurate and a very small search window is precise enough for the determination of conjugate points. The images acquired by High Resolution Stereo Camera (HRSC on European Mars Express were used to verify our method’s feasibility. Experiment results demonstrate that accurate DEM data can be derived with an acceptable time cost by pixel-level image matching.

  16. Determination of N-nitrosodimethylamine at part-per-trillion levels in drinking waters and contaminated groundwaters

    Energy Technology Data Exchange (ETDEWEB)

    Tomkins, B.A.; Griest, W.H.; Higgins, C.E.

    1995-12-01

    N-nitrosodimethylamine is a high, carcinogenic manufacturing by-product of unsymmetrical dimethyl hydrazine a component of rocket fuel. Prior disposal practices resulted in the contamination of groundwater near certain military installations with both species. The current regulatory threshold promulgated by the US Environmental Protection Agency (EPA) for NDMA in surface waters designated for drinking is 0.7 ng NDMA/L (0.7 pptr)L. Existing procedures for determining NDMA in aqueous samples typically employ dichloromethane extraction followed by concentration to a final volume of 1 mL, and gas chromatographic analysis of a 2 {mu}L aliquot of concentrate using either a nitrogen-phosphorus detector (NPD), mass spectrometric detector, or chemiluminescent nitrogen detector (CLND). Such a protocol does not permit detection of NDMA at the desired health-based criterion unless high-resolution mass spectrometric (HRMS) detectors are employed. The analytical procedure described in this work employed an initial solid-phase extraction of groundwater samples with a preconditioned Empore C{sub 18} disk, used to remove interfering neutral species including di-isopropylmethane phosphonate (DIMP), prior to continuous overnight extraction.

  17. Geospatial Data Used in Water-Level and Land-Subsidence Studies in the Mojave River and Morongo Groundwater Basins for 2004

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground-water from these basins supplies a...

  18. Village Level Tsunami Threat Maps for Tamil Nadu, SE Coast of India: Numerical Modeling Technique

    Science.gov (United States)

    MP, J.; Kulangara Madham Subrahmanian, D.; V, R. M.

    2014-12-01

    The Indian Ocean tsunami (IOT) devastated several countries of North Indian Ocean. India is one of the worst affected countries after Indonesia and Sri Lanka. In India, Tamil Nadu suffered maximum with fatalities exceeding 8,000 people. Historical records show that tsunami has invaded the shores of Tamil Nadu in the past and has made people realize that the tsunami threat looms over Tamil Nadu and it is necessary to evolve strategies for tsunami threat management. The IOT has brought to light that tsunami inundation and runup varied within short distances and for the disaster management for tsunami, large scale maps showing areas that are likely to be affected by future tsunami are identified. Therefore threat assessment for six villages including Mamallapuram (also called Mahabalipuram) which is famous for its rock-cut temples, from the northern part of Tamil Nadu state of India has been carried out and threat maps categorizing the coast into areas of different degree of threat are prepared. The threat was assessed by numerical modeling using TUNAMI N2 code considering different tsunamigenic sources along the Andaman - Sumatra trench. While GEBCO and C-Map data was used for bathymetry and for land elevation data was generated by RTK - GPS survey for a distance of 1 km from shore and SRTM for the inland areas. The model results show that in addition to the Sumatra source which generated the IOT in 2004, earthquakes originating in Car Nicobar and North Andaman can inflict more damage. The North Andaman source can generate a massive tsunami and an earthquake of magnitude more than Mw 9 can not only affect Tamil Nadu but also entire south east coast of India. The runup water level is used to demarcate the tsunami threat zones in the villages using GIS.

  19. [Uncertainty analysis of groundwater protection and control zoning in Beijing plain].

    Science.gov (United States)

    Lu, Yan; He, Jiang-Tao; Wang, Jun-Jie; Liu, Li-Ya; Zhang, Xiao-Liang

    2012-09-01

    Groundwater pollution prevention mapping has important meaning to groundwater protection, pollution prevention and effective management. A mapping method was built through combining groundwater pollution risk assessment, groundwater value and wellhead protection area zoning. To make the method more accurate, two series of uncertainty analysis were performed and discussed. One was performed by changing the weights of the toxicity, mobility and degradation of pollutants, and the other was by changing the weights of groundwater pollution risk, groundwater value and wellhead protection area zoning. The results showed that the weights of groundwater pollution risk, groundwater value and wellhead protection area zoning were more sensitive than the weights of toxicity, mobility and degradation of pollutants.

  20. Near real-time monitoring and mapping of specific conductivity levels across Lake Texoma, USA

    Science.gov (United States)

    Atkinson, S.F.; Mabe, J.A.

    2006-01-01

    A submersible sonde equipped with a specific conductivity probe, linked with a global positioning satellite receiver was developed, deployed on a small boat, and used to map spatial and temporal variations in specific conductivity in a large reservoir. 7,695 sample points were recorded during 8 sampling trips. Specific conductivity ranged from 442 uS/cm to 3,378 uS/cm over the nine-month study. The data showed five statistically different zones in the reservoir: 2 different riverine zones, 2 different riverine transition zones, and a lacustrine zone (the main lake zone). These data were imported to a geographic information system where they were spatially interpolated to generate 8 maps showing specific conductivity levels across the entire surface of the lake. The highly dynamic nature of water quality, due to the widely differing nature of the rivers that flow into the reservoir and the effect of large inflows of fresh water during winter storms is easily captured and visualized using this approach. ?? Springer Science+Business Media, Inc. 2006.

  1. Simulation of groundwater flow and interaction of groundwater and surface water on the Lac du Flambeau Reservation, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Fienen, Michael N.; Hunt, Randall J.

    2014-01-01

    resulting simulated lake stage and water budgets to stages and water budgets from the calibrated model. Simulated lake water budgets and water level changes illustrate the importance of understanding the position of a lake within the hydrologic system (headwater or downstream), the type of lake (surface-water drainage or seepage lake), and the role of groundwater in dampening the effects of large-scale changes in weather patterns on lake levels. Areas contributing recharge to drinking-water supply wells on the Reservation were delineated using forward particle tracking from the water table to the well. Monte Carlo uncertainty analyses were used to produce maps showing the probability of groundwater capture for areas around each well nest. At the Main Pumphouse site near the Village of Lac du Flambeau, most of the area contributing recharge to the wells occurs downgradient from a large wetland between the wells and the wastewater infiltration lagoons. Nonetheless, a small potential for the wells to capture infiltrated wastewater is apparent when considering uncertainty in the model parameter values. At the West Pumphouse wells south of Flambeau Lake, most of the area contributing recharge is between the wells and Tippecanoe Lake. The extent of infiltrated wastewater from two infiltration lagoons was tracked using the groundwater flow model and Monte Carlo uncertainty analyses. Wastewater infiltrated from the lagoons flows predominantly south toward Moss Lake as it integrates with the regional groundwater flow system. The wastewater-plume-extent simulations support the area-contributing-recharge simulations, indicating that there is a possibility, albeit at low probability, that some wastewater could be captured by water-supply wells. Comparison of simulated water-table contours indicate that the lagoons may mound the water table approximately 4 ft, with diminishing levels of mounding outward from the lagoons. Four scenarios, representing potential alternatives for wastewater

  2. Application of Distributed Temperature Sensing for coupled mapping of sedimentation processes and spatio-temporal variability of groundwater discharge in soft-bedded streams

    DEFF Research Database (Denmark)

    Sebök, Éva; Calvache, Carlos Duque; Engesgaard, Peter Knudegaard;

    2015-01-01

    -induced temperature anomalies resemble the signal of groundwater discharge while scouring will cause the cable to float in the water column and measure stream water temperatures. DTS applied in a looped layout with nine fibre optic cable rows in a 70 × 5 m section of a soft-bedded stream made it possible to detect......The delineation of groundwater discharge areas based on Distributed Temperature Sensing (DTS) data of the streambed can be difficult in soft-bedded streams where sedimentation and scouring processes constantly change the position of the fibre optic cable relative to the streambed. Deposition...... on the simultaneous interpretation of streambed temperature and elevation data, a method is proposed to delineate potential high-groundwater discharge areas and identify deposition-induced temperature anomalies in soft-bedded streams. Potential high-discharge sites were detected using as metrics the daily minimum...

  3. ROAD MAP FOR DEVELOPMENT OF CRYSTAL-TOLERANT HIGH LEVEL WASTE GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Peeler, D.; Herman, C.

    2014-05-15

    The U.S. Department of Energy (DOE) is building a Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is being temporarily stored in 177 underground tanks. Efforts are being made to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product quality requirements. This road map guides the research and development for formulation and processing of crystaltolerant glasses, identifying near- and long-term activities that need to be completed over the period from 2014 to 2019. The primary objective is to maximize waste loading for Hanford waste glasses without jeopardizing melter operation by crystal accumulation in the melter or melter discharge riser. The potential applicability to the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF) will also be addressed in this road map. The planned research described in this road map is motivated by the potential for substantial economic benefits (significant reductions in glass volumes) that will be realized if the current constraints (T1% for WTP and TL for DWPF) are approached in an appropriate and technically defensible manner for defense waste and current melter designs. The basis of this alternative approach is an empirical model predicting the crystal accumulation in the WTP glass discharge riser and melter bottom as a function of glass composition, time, and temperature. When coupled with an associated operating limit (e.g., the maximum tolerable thickness of an accumulated layer of crystals), this model could then be integrated into the process control algorithms to formulate crystal-tolerant high-level waste (HLW) glasses targeting high waste loadings while still meeting process related limits and melter lifetime expectancies. The modeling effort will be an iterative process, where model form and a broader range of conditions, e.g., glass

  4. ROAD MAP FOR DEVELOPMENT OF CRYSTAL-TOLERANT HIGH LEVEL WASTE GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Peeler, D.; Herman, C.

    2014-05-15

    The U.S. Department of Energy (DOE) is building a Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioac