- Email: [email protected]
Application of groundwater modeling in remedial action development
203A oil/gas well drilling and production operations. A mathematical relation is derived to evaluate the undersaturation in the permafrost at the beginning of each freezeback process during several thaw-subsidence-freezeback cycles. A relation for the initial gas fraction is also developed which can be incorporated in the freezeback model.
914034 Regional modelling of groundwater flow and salt and environmental tracer transport in deep aquifers in the Paris Basin Wei, H F; Ledoux, E; De Marsily, G J Hydrol VI20, NI/4, Dec 1990, P341-358
914031 Variations in ice gouge parameters related to different seabed soil types Ticken, E J; Toimil. L J Proc 9th International Conference on Offshore 34echanics and Arctic Engineering, Houston, 18-23 February 1990 V4, P337339. Publ New York: ASME, 1990
A hydrodynamic model of the deep multilayered aquifer system has been developed. It is based on the finite difference code NEWSMTRID and takes into account aquitard storage effects. It can explain observed hydraulic head, salinity, and transmissivity of the Dogger aquifer. Calibration of the model allows estimation of some unmeasured parameters such as aquifer and aquitard storage coefficients. Simulation of isotope tracer transport further demonstrates the power of the model. Computed Darcy average velocity of the Dogger aquifer is 0.33m/yr.
Mobile sea ice poses multiple threats to offshore pipelines in arctic waters. Tests were carried out to measure the frequency and characteristics of new ice gouge events in the arctic. The tests suggest that ice gouges in a silty sea bed have a longer residence time than those in sandy soils. A higher percentage of deeper gouges noticed in the silt suggests that these gouges may closely reflect the original depth of incision. Details of the tests and the data collected are presented.
914035 Hydrochemical characterization of the water dynamics of a karstic system Vervier, P J Hydrol VI21, NI/4, Dec 1990, P103-117 The origins and evolution of the water flow of the Foussoubie karstic system in France have been investigated. In situ probes monitored temperature and conductivity, whilst samples were analysed in the laboratory within 24 hours of collection. Both a complete hydrologic cycle and a flood event were studied. Evolution of chemical composition of the water, in particular bicarbonate/calcium ratio, permits identification of the type of infiltration which contributes to subterranean flow. A qualitative model to describe degree of contribution of infiltration to subterranean flow is developed.
Hydrogeology Groundwater See also." 914271 914032 Influence of aquifer heterogeneity on contaminant transport at the Hansford site Poeter, E; Gaylord, D R Ground Water V28. N6, Nor-Dec 1990, P900-909 Approximately 300m of unconsolidated sediments overlie the basalt flows at the Hansford site. Disposal of hazardous wastes over many years has led to groundwater contamination. Aquifer heterogeneities defined by mapping and correlating lithofacies and existing geological and borehole geophysical data have been compared to tritium migration trends within the unconfined aquifer. Very large scale migration pathways can be defined, but much more detailed information on mapping of hydrofacies will be necessary before tritium migration paths can be predicted unambiguously and at a practical scale. 914033 Application of groundwater modeling in remedial action development Djafari, S H; Troxell, D E J Hazard Mater V25. N3, Dec 1990, P321-341 Many abandoned and active hazardous waste sites pose risks to human health and the environment. Remedial investigation requires assessment of data needs and key parameters related to final design. Verified groundwater computer models are powerful tools for identifying data gaps and for assessing effectiveness of remedial measures. Analogue, physical, and mathematical models for groundwater behaviour are described and compared for use in remedial investigations. Considerations for model selection and application are discussed, and numerical modelling case studies are presented.
914036 Hydrogeomorphic flood hazard evaluation for semi-arid environments Kenny, R Q J Engng Geol V23, N4, 1990, P333-336 Population explosion into semi-arid areas has prompted study of flood hazards of these regions. A hydrogeomorphic hazard analysis, with geologic, climatic, geometric, and vegetation data superimposed on an aerial photograph, is demonstrated for a region of Arizona. Four flood hazard zones are delineated for management study, and recommendations for development and protective measures presented.
914037 Hydraulic response of highly compressible aquitards during consolidation Rudolph, D L; Frind, E 0 Water Resoar Res V27, NI, Jan 1991, PI7-30 The significance of stress dependent hydraulic parameters on the response of a consolidating aquitard is investigated using numerical analysis and evaluation of field data. Hydraulic conductivity decrease due to consolidation will lead to diminishing leakage flow, lower groundwater velocity and transport rates, longer transient response periods, and lower subsidence than if classical linear theory was used. Evaluation of field data from a site near Mexico City is used to illustrate potential interpretative errors if nonlinearity is not considered.
© 1991 Pergamon Press plc. Reproduction not permitted
914034 Regional modelling of groundwater flow and salt and environmental tracer transport in deep aquifers in the Paris Basin Wei, H F; Ledoux, E; De Marsily, G J Hydrol VI20, NI/4, Dec 1990, P341-358
914031 Variations in ice gouge parameters related to different seabed soil types Ticken, E J; Toimil. L J Proc 9th International Conference on Offshore 34echanics and Arctic Engineering, Houston, 18-23 February 1990 V4, P337339. Publ New York: ASME, 1990
A hydrodynamic model of the deep multilayered aquifer system has been developed. It is based on the finite difference code NEWSMTRID and takes into account aquitard storage effects. It can explain observed hydraulic head, salinity, and transmissivity of the Dogger aquifer. Calibration of the model allows estimation of some unmeasured parameters such as aquifer and aquitard storage coefficients. Simulation of isotope tracer transport further demonstrates the power of the model. Computed Darcy average velocity of the Dogger aquifer is 0.33m/yr.
Mobile sea ice poses multiple threats to offshore pipelines in arctic waters. Tests were carried out to measure the frequency and characteristics of new ice gouge events in the arctic. The tests suggest that ice gouges in a silty sea bed have a longer residence time than those in sandy soils. A higher percentage of deeper gouges noticed in the silt suggests that these gouges may closely reflect the original depth of incision. Details of the tests and the data collected are presented.
914035 Hydrochemical characterization of the water dynamics of a karstic system Vervier, P J Hydrol VI21, NI/4, Dec 1990, P103-117 The origins and evolution of the water flow of the Foussoubie karstic system in France have been investigated. In situ probes monitored temperature and conductivity, whilst samples were analysed in the laboratory within 24 hours of collection. Both a complete hydrologic cycle and a flood event were studied. Evolution of chemical composition of the water, in particular bicarbonate/calcium ratio, permits identification of the type of infiltration which contributes to subterranean flow. A qualitative model to describe degree of contribution of infiltration to subterranean flow is developed.
Hydrogeology Groundwater See also." 914271 914032 Influence of aquifer heterogeneity on contaminant transport at the Hansford site Poeter, E; Gaylord, D R Ground Water V28. N6, Nor-Dec 1990, P900-909 Approximately 300m of unconsolidated sediments overlie the basalt flows at the Hansford site. Disposal of hazardous wastes over many years has led to groundwater contamination. Aquifer heterogeneities defined by mapping and correlating lithofacies and existing geological and borehole geophysical data have been compared to tritium migration trends within the unconfined aquifer. Very large scale migration pathways can be defined, but much more detailed information on mapping of hydrofacies will be necessary before tritium migration paths can be predicted unambiguously and at a practical scale. 914033 Application of groundwater modeling in remedial action development Djafari, S H; Troxell, D E J Hazard Mater V25. N3, Dec 1990, P321-341 Many abandoned and active hazardous waste sites pose risks to human health and the environment. Remedial investigation requires assessment of data needs and key parameters related to final design. Verified groundwater computer models are powerful tools for identifying data gaps and for assessing effectiveness of remedial measures. Analogue, physical, and mathematical models for groundwater behaviour are described and compared for use in remedial investigations. Considerations for model selection and application are discussed, and numerical modelling case studies are presented.
914036 Hydrogeomorphic flood hazard evaluation for semi-arid environments Kenny, R Q J Engng Geol V23, N4, 1990, P333-336 Population explosion into semi-arid areas has prompted study of flood hazards of these regions. A hydrogeomorphic hazard analysis, with geologic, climatic, geometric, and vegetation data superimposed on an aerial photograph, is demonstrated for a region of Arizona. Four flood hazard zones are delineated for management study, and recommendations for development and protective measures presented.
914037 Hydraulic response of highly compressible aquitards during consolidation Rudolph, D L; Frind, E 0 Water Resoar Res V27, NI, Jan 1991, PI7-30 The significance of stress dependent hydraulic parameters on the response of a consolidating aquitard is investigated using numerical analysis and evaluation of field data. Hydraulic conductivity decrease due to consolidation will lead to diminishing leakage flow, lower groundwater velocity and transport rates, longer transient response periods, and lower subsidence than if classical linear theory was used. Evaluation of field data from a site near Mexico City is used to illustrate potential interpretative errors if nonlinearity is not considered.
© 1991 Pergamon Press plc. Reproduction not permitted