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Non stationary geostatistics
3A pipe with gravel. Thermal simulations of frost bulb growth and predictions of frost heave using the segregation potential model agree well with the observations. Auth.
between inflow into the borehole and drawdown. An automated numerical procedure to analyse slug test data is presented, which is based on sensitivity analysis for parameter estimation. The solution has been validated using computer generated data. An application to a field problem is illustrated.
Hydrogeology Groundwater
891019
Pumping tests in nonuniform aquifers - the radially symmetric case Butler, J J J Hydrol VIOl, NI-4o June 1988. P15-30
See also: 891113, 891114, 891115 891015 Non stationary geostatisties
de Marsily, G In: Advances in Transport Phenomena in Porous Media, edited by J Bear and M Y Corapcioglu P635-655. Publ Dordrecht: Martinus Nijhoff. 1987 Non stationary variables in geostatistics are those which show a definite trend in space, such as the direction of hydraulic gradient for hydraulic heads in an aquifer. Simple kriging may be used for stationary variables. Universal kriging and the use of generalised covariances of order k are summarised, to estimate the values of non stationary hydrologic variables at all other locations. A worked example is presented. 891016 Uncertainty assessment for fluid flow and contaminant
transport modelling in heterogeneous groundwater systems Nelson, R W: Jacobson, E A; Conbere, W In: Advances in Transport Phenomena in Porous Media, edited by J Bear and M Y Corapeioglu P701-726. Publ Dordrecht: Martinus Nijhoff, 1987
Methods for pumping test analysis have been limited to aquifers whose properties are assumed uniform in space. The applicability of analytical methods to aquifers with spatially varying properties is considered. A simple analytical solution to the radial flow problem is derived using a straightforward Laplace transform procedure. Implementation of the solution for pumping test analyses and implications for pumping tests in nonuniform aquifers are discussed.
891020 Hydrogeology of two Saskatchewan tills, I. Fractures, bulk permeability, and spatial variability of downward flow
Keller, C K, Van der Kamp, G; Cherry, J A J Hydrol VIOl, NI-4, June 1988. P97-121
891017
Groundwater flow patterns in two deposits of clayey till overlying a regional aquifer were compared. Analysis of field and laboratory hydraulic conductivity tests showed conductive fractures in the unoxidised zone of the thinner till gave rise to isotropic bulk permeability two orders of magnitude greater than bulk permeability of unoxidised till in the thicker deposit. Spatially detailed water level monitoring and test drilling indicated substantial variation of the flow regime at the thinner till site on a horizontal scale of tens of metres, whilst no such variation existed at the other site. This differentiation is due to higher till permeability. Implications of flow regime variability for landuse management are discussed.
Sensitivity analysis of ground-water models McElwee, C D In: Advances in Transport Phenomena in Porous Media, edited by J Bear and M Y Corapcioglu P751-817. Publ Dordrecht: Martinus Nijhoff. 1987
891021
It is desirable that uncertainties in groundwater flow and transport modelling in inhomogeneous media should be evaluated for subsurface contamination problems, particularly where the likelihood or consequence of serious errors is large. An analysis method is presented, based on stochastic and statistical tools combined with more traditional physically based deterministic models. Geostatistical analysis of field parameters is used to characterise the system. Examples are shown.
Prediction of aquifer parameters is often based on historical head data and sparse field measurements of varying quality. For each model parameter a sensitivity coefficient is defined, which depends on choice of model, spatial co-ordinates, time variables, number and type of model parameters, and boundary conditions. Methods of determining sensitivity coefficients are discussed. The sensitivity coefficients can be used to estimate variance and confidence limits of aquifer parameters. General guidelines for designing models with the desired sensitivity to model parameters are developed. 891018 Automated numerical evaluation of slug test data
Kemblowski, M W; Klein, C L Ground Water V26, N4. July-Aug 1988, P435-438
The slug test is widely used to estimate hydraulic properties of aquifers because of its simplicity. The theory of the problem is based on the Thiem equation, which describes the relation
Hydrogeology of two Saskatchewan tills, II. Occurrence of sulfate and implications for soil salinity Keller, C K; Van der Kamp, G J Hydrol VIOl, NI-4, June 1988. P123-144 Occurrence of sulphate salts in groundwater and solids was documented at two sites, Dalmeny and Warman, where clayey tills overlie regional aquifers. Samples were collected to 14m depth and at horizontal spacings of a few tens of metres. Results showed that bulk sulphur and sulphate contents of solids couldnot be characterised with point or 'grab' samples from boreholes. Sulphate variability coincides with groundwater flow patterns determined previously, showing that bulk permeability of the till controls the effect of microtopographic focusing of surface water input on the subsurface sulphate 'reservoir'. Where tills are permeable, land management will affect groundwater recharge to underlying aquifers and where tills have low permeability, land management would affect potential for surface and soil salinisation.
:9 1989 Pergamon Press plc. Reproduction not permitted
between inflow into the borehole and drawdown. An automated numerical procedure to analyse slug test data is presented, which is based on sensitivity analysis for parameter estimation. The solution has been validated using computer generated data. An application to a field problem is illustrated.
Hydrogeology Groundwater
891019
Pumping tests in nonuniform aquifers - the radially symmetric case Butler, J J J Hydrol VIOl, NI-4o June 1988. P15-30
See also: 891113, 891114, 891115 891015 Non stationary geostatisties
de Marsily, G In: Advances in Transport Phenomena in Porous Media, edited by J Bear and M Y Corapcioglu P635-655. Publ Dordrecht: Martinus Nijhoff. 1987 Non stationary variables in geostatistics are those which show a definite trend in space, such as the direction of hydraulic gradient for hydraulic heads in an aquifer. Simple kriging may be used for stationary variables. Universal kriging and the use of generalised covariances of order k are summarised, to estimate the values of non stationary hydrologic variables at all other locations. A worked example is presented. 891016 Uncertainty assessment for fluid flow and contaminant
transport modelling in heterogeneous groundwater systems Nelson, R W: Jacobson, E A; Conbere, W In: Advances in Transport Phenomena in Porous Media, edited by J Bear and M Y Corapeioglu P701-726. Publ Dordrecht: Martinus Nijhoff, 1987
Methods for pumping test analysis have been limited to aquifers whose properties are assumed uniform in space. The applicability of analytical methods to aquifers with spatially varying properties is considered. A simple analytical solution to the radial flow problem is derived using a straightforward Laplace transform procedure. Implementation of the solution for pumping test analyses and implications for pumping tests in nonuniform aquifers are discussed.
891020 Hydrogeology of two Saskatchewan tills, I. Fractures, bulk permeability, and spatial variability of downward flow
Keller, C K, Van der Kamp, G; Cherry, J A J Hydrol VIOl, NI-4, June 1988. P97-121
891017
Groundwater flow patterns in two deposits of clayey till overlying a regional aquifer were compared. Analysis of field and laboratory hydraulic conductivity tests showed conductive fractures in the unoxidised zone of the thinner till gave rise to isotropic bulk permeability two orders of magnitude greater than bulk permeability of unoxidised till in the thicker deposit. Spatially detailed water level monitoring and test drilling indicated substantial variation of the flow regime at the thinner till site on a horizontal scale of tens of metres, whilst no such variation existed at the other site. This differentiation is due to higher till permeability. Implications of flow regime variability for landuse management are discussed.
Sensitivity analysis of ground-water models McElwee, C D In: Advances in Transport Phenomena in Porous Media, edited by J Bear and M Y Corapcioglu P751-817. Publ Dordrecht: Martinus Nijhoff. 1987
891021
It is desirable that uncertainties in groundwater flow and transport modelling in inhomogeneous media should be evaluated for subsurface contamination problems, particularly where the likelihood or consequence of serious errors is large. An analysis method is presented, based on stochastic and statistical tools combined with more traditional physically based deterministic models. Geostatistical analysis of field parameters is used to characterise the system. Examples are shown.
Prediction of aquifer parameters is often based on historical head data and sparse field measurements of varying quality. For each model parameter a sensitivity coefficient is defined, which depends on choice of model, spatial co-ordinates, time variables, number and type of model parameters, and boundary conditions. Methods of determining sensitivity coefficients are discussed. The sensitivity coefficients can be used to estimate variance and confidence limits of aquifer parameters. General guidelines for designing models with the desired sensitivity to model parameters are developed. 891018 Automated numerical evaluation of slug test data
Kemblowski, M W; Klein, C L Ground Water V26, N4. July-Aug 1988, P435-438
The slug test is widely used to estimate hydraulic properties of aquifers because of its simplicity. The theory of the problem is based on the Thiem equation, which describes the relation
Hydrogeology of two Saskatchewan tills, II. Occurrence of sulfate and implications for soil salinity Keller, C K; Van der Kamp, G J Hydrol VIOl, NI-4, June 1988. P123-144 Occurrence of sulphate salts in groundwater and solids was documented at two sites, Dalmeny and Warman, where clayey tills overlie regional aquifers. Samples were collected to 14m depth and at horizontal spacings of a few tens of metres. Results showed that bulk sulphur and sulphate contents of solids couldnot be characterised with point or 'grab' samples from boreholes. Sulphate variability coincides with groundwater flow patterns determined previously, showing that bulk permeability of the till controls the effect of microtopographic focusing of surface water input on the subsurface sulphate 'reservoir'. Where tills are permeable, land management will affect groundwater recharge to underlying aquifers and where tills have low permeability, land management would affect potential for surface and soil salinisation.
:9 1989 Pergamon Press plc. Reproduction not permitted