Aquifer Mechanics - FORS(GEOL) 8730
|
|
- Ethelbert Foster
- 5 years ago
- Views:
Transcription
1 Aquifer Mechanics - FORS(GEOL) 8730 Todd Rasmussen (2-4300) John Dowd (2-2383) February 11, 2004 Course Summary This course focuses on understanding the mechanics of flow through subsurface media. Theories of flow include: confined homogeneous aquifers, leaky aquifers, delayed yield, effects of partially penetrating wells, unconfined (water table) aquifers, effects of boundaries and multiple wells, dual porosity media, fractured rock aquifers. Applications focus on using pump test data to identify the relative importance of flow and transport processes and to estimate hydraulic properties of aquifers. Textbook Kruseman GP, de Ridder NA, 1991, Analysis and Evaluation of Pumping Test Data, Second Edition, International Institute for Land Reclamation and Improvement, P.O. Box 45, 6700 AA Wageningen, The Netherlands 1
2 Contents 1 Introduction to Aquifer Testing Notation Definitions of Hydraulic Properties Common Errors Aquifer Test Preliminaries Ground-Water Flow Geometries Flow Parallel to Bedding Flow in Series Through Bedding Flow at an Angle to the Bedding The Ground-Water Flow Equation in Radial Coordinates 16 4 Flow in Confined Aquifers Unsteady Flow in Confined Aquifers (Theis Method) Unsteady Flow Problem Example Estimating the Theis Parameters Confined Aquifer Parameter Sensitivity Coefficients Aquifer Derivative Curves Flow in Leaky Aquifers Steady Flow in a Leaky Aquifer Unsteady, Leaky Flow (Hantush-Jacob Method) The Universal Confining Layer (by P. Stone)
3 1 Introduction to Aquifer Testing 1.1 Notation Physical Properties Aquifer thickness, b Aquitard thickness, b Aquifer porosity, n = Vv V b = n e + n i Volume of voids, V v Bulk volume, V b Aquifer effective porosity, n e Immobile zone porosity, n i Bulk density, ρ b = (1 n) ρ s Skeletal density, ρ s = 2.65 g/cm 3 Water content, θ = Vw V v Relative saturation, Θ = theta n = Vw V b Conductance Parameters Aquifer hydraulic conductivity, K = k γ µ Intrinsic permeability, k d 2 Pore diameter, d Fluid specific weight, γ = ρ w g = 9807 P a/m Fluid density, ρ w = 1 g/cm 3 Fluid dynamic viscosity, µ = P a s Aquifer transmissivity, T = K h b Horizontal component of hydraulic conductivity, K h 3
4 Vertical component of hydraulic conductivity, K v or K Anisotropy ratio, m = K h K v = K K Hydraulic conductance, C = Kv = K b b Hydraulic resistance, c = 1 C = b K Aquitard leakance, L = T c = T K b b C K = m b b K xx K xy K x z Hydraulic conductivity tensor, K = K yx K yy K y z K zx K zy K z z Flow Parameters Hydraulic head, h = z + p γ + v2 2 g Elevation, z Fluid pressure, p Fluid specific weight, γ = ρ g Fluid density, rho Gravitational constant, g = 9.807m/s 2 Hydraulic gradient vector, ı = [i x, i y, i z ] = gradh = [ h, h, ] h x y z Fluid flux vector, q = Q A = [q x, q y, q z ] = K h Fluid flow, Q = Vw t Cross sectional area, A Richards equation, q = D θ Aquitard flux, q = K h b = L h Storage Parameters Specific storativity, S s = θ h = [ Vw Vb ] h = Vw V 2 b V b h 1 V b V w h = Vw V b [ 1 V b V b h 1 V w ] V w h = γ n (β w β s ) = γ (α + n β w ) 4
5 Water compressibility, β w = 1 V w V w p = P a 1 = m 1 Aquifer compressibility, α = 1 V b V b p Effective stress, p Bulk volume, V b Skeletal compressibility, β s Barometric efficiency, BE = n/s s Tidal efficiency, T E = 1 BE Aquifer storativity, S = b S s Aquifer hydraulic diffusivity, D = K/S s =T/S Specific yield, S y = b θ h = b θ h Transport Parameters Solute effective dispersion coefficient, D e = D o + α v Molecular diffusion coefficient, D o Solute dispersivity, α Average fluid pore velocity, v Retardation factor, R = 1 + ρ b n K d Distribution coeficient, K d Cation exchange capacity, CEC Anion exchange capacity, AEC Organic carbon content, OC Specific surface area, S a Sorption kinetic parameter, k Additional Aquifer Parameters 5
6 Specific capacity, C p = Q/s Pumping rate, Q Aquifer drawdown, s Recharge rate, R Deep percolation rate, DP 1.2 Definitions of Hydraulic Properties Anisotropic: hydraulic conductivity is differ in different directions. We must represent the hydraulic conductivity, K, using a tensor Anisotropy ratio: Ratio of hydraulic conductivity in one principal direction to the hydraulic conductivity in another principal direction. Aquiclude: A geologic formation in which negligible fluid flow is possible Aquifer: A geologic formation that transmits appreciable quantities of water to a well Aquifer Compressibility: reciprocal of bulk modulus of elasticity of aquifer where is the effective stress. ranges from 10 6 P a 1 for clays, to P a 1 for rock Aquitard or confining layer: geologic formation that resists the movement of water between two aquifers. The layer has material properties K and b to distinguish them from aquifer properties. Flow through a confining layer can be assumed to be vertical: Conductance: hydraulic conductivity of resistive layer (K ) per unit thickness of the resisting layer (b ): Darcian flux: see flux Darcy s Law: relates hydraulic flux to hydraulic gradient and hydraulic conductivity 6
7 Dimension of Flow: Cartesian Flow: flux is different in each of the three cartesian directions Planar Flow: flux is different in two directions, but zero in one cartesian direction Linear Flow: flux is different in one cartesian direction, but zero in the other two Radial or Cylindrical Flow: flux is planar, radiating inward or outward from a central axis. Spherical Flow: flux is radiating uniformly in all three directions from a point Discharge: Water moving from the subsurface to the surface across the earth s surface Drawdown: water level decline due to pumping from well, where h i is baseline (initial) water level before pumping and h is observed water level during aquifer test. Flux: Volume of water (V w ) flowing per unit area (A) per unit time (t) Homogeneous Media: K is a constant is space Hydraulic Resistance: the reciprocal of the conductance (C) Hydraulic conductivity: Measure of ability of geologic media to transmit water, related in a general way to pore size and shape: C = constant of proportionality d = median pore or grain size γ specific weight of fluid used to measure total head µ = water dynamic viscosity 7
8 Hydraulic Diffusivity: ratio of hydraulic conductivity to specific storage, or, equivalently, of transmissivity to the storage coefficient Hydraulic Gradient: Change in total head per unit distance (h) Infiltration: Water passing across the earth s surface into the subsurface Isotropic: hydraulic conductivity is the same in all directions. It can be represented as a scalar Leakance, or Leakage factor Microporosity or matrix porosity: pores too small to see, such as voids between mineral grains or clay platelets. Macroporosity: visible pores, such as fractures, voids or vugs Nonlinear: K is not constant for all values of total head or fluid potentials Percolation: Water moving through the unsaturated zone Porosity: volume of voids (V v ) per unit bulk volume (V b ), ranging from 10 5 for dense granites to over 0.70 for volcanic tuffs. Precipitation: Water falling on the surface of the earth Recharge: Water moving across the water table from the unsaturated zone into the saturated zone Relative Saturation: Water content of material relative to saturated water content: Richards Equation: relates hydraulic flux to change in volume of water in storage Specific Capacity: water discharge from well divided by amount of drawdown Specific Storage: A measure of the volume of water released (or added) to storage, per unit volume of aquifer, per unit increase (or decrease) in fluid pressure. It 8
9 is the sum of the aquifer plus water compressibilities: where is the fluid specific weight, is the bulk compressibility, is the compressibility of water, and = - n is the compressibility of the mineral skeleton. Specific Yield: volume of water released (or added) from an unconfined aquifer per unit area of aquifer per unit decline (rise) in water table position. Similar to the storage coefficient for confined aquifers. Storage Coefficient: water released from storage for a given thickness of aquifer (b). Storativity: Identical to the storage coefficient Total Head: sum of elevation, pressure, velocity, osmotic and other potentials Transmissivity: Total hydraulic conductivity for a given aquifer thickness Water Compressibility: reciprocal of bulk modulus of elasticity of water where p is the water pressure. Water Content: volume of water (V w ) per bulk volume of aquifer (V b ) 1.3 Common Errors DANGER #1: q and v are not the same! q is specific flux (units of velocity) v is groundwater velocity (units of velocity) DANGER #2: Darcy s Law is not always valid! Darcy s law is only appropriate for laminar, and not turbulent flow, turbulent conditions arise in large voids (fractures, caves, etc.), and where velocities are high, such as near boreholes. 9
10 The Reynolds number helps to define the conditions for laminar flow d is void opening, is kinematic viscosity (approximately 10 6 m 2 /s), R is the ratio of inertial to viscous forces. When the inertial forces are too great, such as when R > 1, then flow can become turbulent. For turbulent conditions, the flow rate varies with the square root of the gradient. 1.4 Aquifer Test Preliminaries Definition of Test Objectives scientific vs engineering objectives identification of system behavior estimation of system parameters scale of interest local vs regional test short-term vs long-term effects hydraulic vs transport effects average or extreme behavior fluid vs solute migration Definition of Conceptual Model Define state of knowledge of area Type of aquifer Type of geologic media, homogeneous/heterogeneous, isotropic/anisotropic Geometries of aquifers and confining units Recharge and discharge areas 10
11 Inventory existing wells in area for baseline (reference) data Find local and regional flow gradients, horizontally and vertically Use the ground and surface water chemical characteristics to indicate of flow system Physical Installation Pumping well: Type of gravel or sand pack Depth of well Well and borehole diameters Length of screened interval and screen integrity Depth of pump, pumping capacity, and previous pumping records Measurement of pumped water rate and duration Location of discharge Observation wells: Number and location (distance from well and depth): Barometric pressure Precipitation Nearby surface water levels Reference ground water levels Aquifer test data: Discharge sampling (flow meter, weir, bucket, etc) and control (valves, voltage) Manual (steel tape, electrical sounder) vs automated (pressure transducer, float) Analog (strip charts) vs digital (computer) 11
12 Water level sampling rates and duration Well effects (cascading water, water quality changes) Aquifer test data interpretation Removing background effects Loading effects due to barometric pressure, rainfall, oceanic and earth tides Trends (seasonal or short-term) Fluid column density effects (salinity, temperature, dissolved gasses) Identifying aquifers type confined aquifer (leaky, double porosity, fractured rock) unconfined aquifer (delayed yield) Identifying other effects well bore storage (and excessive pumping rate) partial penetration boundaries Standard plots horizontal-axis: log t or log(t/r 2 ) vertical-axis: s or log s Derivative plots horizontal-axis: log t or log(t/r 2 ) vertical-axis: s/ t or s/( log t) 12
13 2 Ground-Water Flow Geometries 2.1 Flow Parallel to Bedding Let us assume that two permeable layers overlie each other with horizontal flow in each layer, and no flow between each layer. The flow in each layer is: Q 1 = Q 2 = h K 1 A a h b 1 x a x b (1) h K 2 A a h b 2 x a x b where A 1 = w b 1 and A 2 = w b 2. We sum the amount of flow in each layer: Q h = Q 1 + Q 2 Q h = K h A ha h b x a x b (2) where A = A 1 + A 2 = w (b 1 + b 2 ) = w b, and K h is the effective horizontal hydraulic conductivity. Substitution results in: K h A ha h b x a x b = K 1 A 1 h a h b x a x b + K 2 A 2 h a h b x a x b K h A = K 1 A 1 + K 2 A 2 A K h = K K A 2 A 2 A K h = K 1 b 1b + K 2 b 2b (3) We can also write this in terms of transmissivity: T e = T 1 + T 2 (4) because T e = K e b, T 1 = K 1 b 1, and T 2 = K 2 b 2. For multiple layers, we have: T e = n i=1 T i K e = n i=1 b i K i n i=1 b i (5) 2.2 Flow in Series Through Bedding In this case the flow is perpendicular to the beds: Q 1 = Q 2 = K 1 A ha h b z a z b (6) K 2 A h b h c z b z c 13
14 where A is the same for each bed. In this case, the flows are equal to each other: Q v = Q 1 = Q 2 K v A ha hc b = K 1 A ha h b b 1 = K 2 A h b h c b 2 (7) K v h a h c b = K 1 h a h b b 1 = K 2 h b h c b 2 where b = z a z c, b 1 = z a z b, b 2 = z b z c. Solving for the intervening head, h b, yields: h b = K 1 h c b 1 h a + K 2 b 2 K 1 b 1 + K (8) 2 b 2 Substituting into the previous equation yields: K v b h a h c = K 1 b 1 [ K v 1 b = b 1 + b 2 K 1 K 2 h a b K v = b 1 K 1 + b 2 K 2 K 1 b 1 h a+ K 2 b 2 h c K 1 + K 2 b 1 b 2 ] (9) or, by using the hydraulic resistance, c = K, we have: b c v = c 1 + c 2 (10) Thus, like transmissivity, the hydraulic resistance adds. For multiple aquifers this is: c v = n i=1 c i (11) K v = ni=1 ni=1 b i b i (12) K i 2.3 Flow at an Angle to the Bedding In general, we can define the horizontal and vertical components of flux using: q = Q A = [q h, q v ] = [K h i h, K v i v ] (13) where i h = h and i x v = h z The magnitude of the hydraulic gradient, i, and flux q, are: i 2 = q 2 = 14 i 2 h + i 2 v q 2 h + q 2 v (14)
15 The flux components can be determined from the direction, φ and magnitude, q, of flow: Substitution provides: q h = q v = q cos φ q sin φ (15) (K e i ) 2 = (K h i h ) 2 + (K v i v ) 2 (16) Simplification yields: K e = i 2 h i 2 K 2 h + i2 v i 2 K 2 v cos 2 φ K 2 h + sin2 φ K 2 v K h cos 2 φ + m sin 2 φ (17) where m = K v /K h is the anisotropy ratio. If the hydraulic gradient is at an angle of 45 to the bedding planes, we have: K e = K 2 h + K2 v 2 = K x 1 + m 2 2 (18) If the flux is at an angle of 45 to the bedding planes, we have q h = q v, so that K h i h = K v i v, and m = i x /i v, resulting in: K e = K h 2 m m 2 (19) 15
16 3 The Ground-Water Flow Equation in Radial Coordinates We derive the well flow equation by first defining a representative cylindrical volume with fixed height, b, an inner radius, r 1, and an outer radius, r 2 = r 1 + r. Flow across the inner surface, Q 1, and outer surface, Q 2, are: Q 1 = q 1 A 1 Q 2 = q 2 A 2 (20) with A i = 2 π r i b and q i = K ( ) h, and where A is the cross-sectional area of the r i cylinder perpendicular to the flow direction, q is the darcian flux across the cylindrical face, K is the hydraulic conductivity of the medium within the cylinder, i = h r is the hydraulic gradient, h is the hydraulic head, and r is the radial distance from the center axis of the cylinder. Combining terms yields: Q i = 2 π b K r i We now specify the mass balance equation as: ( ) h r i (21) Q = Q 1 Q 2 = V w t (22) where V w is the change in volume of water within the cylinder needed to balance the inflows with the outflows, and T is time. The change in the volume of water within the cylinder is related to the change in the water content, θ, within the cylinder using: where V b is the volume of the hollow cylinder, equal to: θ = V w V b (23) V b = V 2 V 1 = b π [ r 2 2 r 2 1 ] = b π r 2 (24) We can relate the hydraulic head to the water content using: S s = θ h (25) 16
17 where S s is the specific storage coefficient. Combining equations yields: 2 π b K [ ( ) h r 2 r 2 ( ) ] h r 1 = π b S s r 2 h t (26) r 1 which is the same as: 2 K [ r ( )] h r 2 K [ r ( h r r 2 = S s r 2 h t )] h = S s t )] (27) (28) 2 D [ r ( h r = S r 2 s h t (29) (30) where D = T S is the hydraulic diffusivity, and the partials are introduced to denote infinitesimal changes. We can simplify this further by noting that r2 r = 2 r: D [ r ( )] h r = h t (31) [ r r 2 ] h h D + 1r = h t (32) r2 r 2 h h + 1r r2 r = 1 h t (33) D (34) 17
18 4 Flow in Confined Aquifers 4.1 Unsteady Flow in Confined Aquifers (Theis Method) We start with the ground-water flow equation: T [ 2 h r + 1 ] 2 r h r = S h t [ 2 h D r + 1 ] 2 r h r = h t 2 h r r h r = 1 D h t (35) (36) (37) (38) 4.2 Unsteady Flow Problem Example Find the distance from a pumping well where the drawdown is 1 foot, given: Radius of pumping well, r o = 2 = ft Hydraulic conductivity, K = ft/min Aquifer saturated thickness, b = 10 ft Specific yield, S y = 0.1 ft 3 /ft 3 /ft Pumping duration, t = 3 days = 72 hrs = 4320 min Drawdown at pumped well, s o = 10 ft Derived Parameters: Aquifer Transmissivity, Storage Coefficient, and Diffusivity are: T = S = D = Kb = ( ft/min) (10 ft) = ft 2 /min S y b = [0.1 (ft 3 water)/(ft 3 soil)/(ft drawdown)] (10 ft soil) = 1 ft 3 /ft 2 /ft T/S= (K b)/(s y b) = K/S y = ft/min/0.1 ft 3 /ft 3 /ft = ft 2 /min (39) The well function argument is: u o = r2 o 4Dt = ( ft) 2 4 ( ft 2 /min) (4320 min) = (40) 18
19 This satisfies the Jacob condition: u < 0.01, so the well function at the pumped well is: W (u o ) = ln u = 6.55 (41) The pumping rate must be: Q = 4T s o W (u o ) = 4 ( ft 2 10 ft /min) 6.55 = ft3 /min = gpm (42) The well function at the observation well is simply: W (u 1 ) = W (u o ) s 1 s o = ft 10 ft The well function argument at the observation well is: = (43) u 1 = exp( W (u 1 ) = (44) The distance at which the drawdown is 1 foot is: r = 4 D t u 1 = 4 ( ft 2 /min) (4320 min) = 3.18 feet (45) 4.3 Estimating the Theis Parameters The following data are normally provided for an aquifer test: Q, aquifer pumping rate (constant) r, distance of observation well from pumping well (constant) s, drawdown vector in observation well t, time vector at which drawdowns are measured We can remove the constants Q and r from consideration by defining two normalized variables, a normalized drawdown, w, and a normalized time, tau : so that the Theis Solution becomes: w i = 4 π s i Q τ i = 4 t i (46) r 2 w i = W (u i) u i = 1 (47) T D τ i Our objective is to determine the following aquifer parameters: 19
20 D, aquifer diffusivity T, aquifer transmissivity S = T/D, aquifer storage coefficient It is clear that there are two parameters to determine, T and D. The storage coefficient is determined once D and T are known. Two unknowns require two equations, which we select to be the observed drawdowns at two separate times: w 1 = W (u 1) T w 2 = W (u 2) T (48) (49) u 1 = 1 D τ 1 (50) u 2 = 1 D τ 2 (51) (52) We can remove T from these equations by taking the ratio of the normalized drawdown at two different times: ln w 1 = W (u 1) (53) w 2 W u 2 w 1 W (u 2 ) = 1 (54) w 2 W u [ 1 ] w1 W (u 2 ) = 0 (55) w 2 W u 1 (56) which is now only a function of the unknown diffusivity, D. We solve for this unknown at each time step using Newton s method: D j+1 = D j F (D j) f(d k ) The functions, F (D) and f(d), are defined as: F (D j ) = ln [ ] w1 W (u 2 ) w 2 W u 1 (57) (58) 20
21 f(d j ) = df (D) dd (59) (60) Solving for f(d) is assisted by use of the chain rule: d [ln y] dd = d [ln y] dy y u u D (61) We can show that: f(d) = 1 D [ exp u2 W (u 2 ) exp u ] 1 W (u 1 ) (62) so that: D j+1 = D j 1 ln [ w 1 W (u 2 ) w 2 W (u 1 ) e u 2 W (u 2 ) e u 1 W (u 1 ) ] (63) Iteration proceeds until the aquifer diffusivity converges. Upon convergence, we calculate the aquifer transmissivity and storage coefficient for each time step using: T i = W (u i) w i (64) S i = T i D i (65) 4.4 Confined Aquifer Parameter Sensitivity Coefficients Confined aquifer sensitivity coefficients are used to relate changes in drawdown (raw, U, and normalized, U ) to each of the coefficients that determine drawdown. s = U r = U t = U T = U S = U D = Q 4 π T W (u) s = Q r 4 π T s = t s = T Q 4 π T Q 4 π T 2 e u r e u t e u W (u) T s = Q S 4 π T s = D Q 4 π T e u S e u T (66) The sensitivity between T and D is: D T = U T U S = e u W (u) S e u (67) 21
22 The sensitivity between T and S is: S T = U T U S = Note that T and S are independent of each other when: W (u) e u D e u (68) S T = 0 (69) which occurs when W (u) = e u. T and D are independent for these same conditions. In fact, drawdowns are insensitive to transmissivity at this point, because U T = 0 for this condition. This condition is satisfied at u = Aquifer Derivative Curves We calculate derivative curves using observed drawdowns: For normalized variables, this is: s = U t = s t = Q 4 π T e u t (70) w = U t w = 4 π s Q = e u T τ = W (u) T (71) (72) τ = 4 t r 2 (73) u = 1 D τ (74) The maximum of this function is found by setting the derivative of w to zero: (75) w = 2 w τ 2 = e u (u 2 1) T τ 2 = 0 (76) which occurs when u = 1. This implies that at the time of the maximum, t, and the value of drawdown at the maximum, w, can be used to determine aquifer parameters, D = 1/t, because: T = W (1) = w w w = S = W (u) T T D = τ w (77) 22
23 5 Flow in Leaky Aquifers 5.1 Steady Flow in a Leaky Aquifer For a leaky aquifer, we have: T [ 2 s r + 1 ] 2 r s r q = 0 (78) We account for leakage using: q = K b s = s c (79) Dividing by the aquifer transmissivity yields the equation: where L 2 = T c. 2 s r r s r s L 2 = 0 (80) This form is similar to the Modified Bessel Function Differential Equation (Abramowitz and Stegun, 9.6.1): z 2 2 w z 2 + z w z ( z 2 + v 2) w = 0 (81) for the conditions: v = 0 (82) s = w (83) z = r L (84) (85) The Modified Bessel Function solution for v = 0 is: w = K o (z) = for boundary conditions: o cos zt t2 + 1 dt = o lim z w = 0 lim z 0 z w z = 1 cos(z sinh t) dt (86) (87) 23
24 Our boundary conditions are: which yields the solution: lim r s = 0 lim r 0 s = r s r = Q 2 π T Q ( ) r 2 π T K o L (88) (89) Leakage into aquifers during well tests often result in steady flow conditions. This attribute is quantified using the specific capacity coefficient, C p : C p = Q s = 2 π ( T ) K r (90) o L 5.2 Unsteady, Leaky Flow (Hantush-Jacob Method) For unsteady flow conditions we have: We again account for leakage using: T [ 2 s r + 1 ] 2 r s r S s t q = 0 (91) q = K b s = s c (92) Dividing by the aquifer transmissivity yields the equation: where L 2 = T c. 2 s r r s r 1 D s t s L 2 = 0 (93) Using the same approach as the solution for the confined (Theis) equation: which is equivalent to: u 2 u [ 2 ] s u + s u + s 2 u r2 s 4 u L = 0 (94) 2 2 s s + u [u + 1] s u + u2 u r2 s 4 u L = 0 (95) 2 We can find an approximate solution for Jacob conditions, i.e., u << 1: u 2 2 s s + u s u + u2 u [ u 2 + v 2] s = 0 (96) 24
25 where: yielding: v = s = r 2 4 L 2 u2 (97) Q 4 π T K v(u) (98) which holds as long as u < 0.01 and r > u 2 L Hantush and Jacob found a solution for all u: s = Q 4 π T which is also known as the Walton solution. u exp [ x x ] r2 4 r L 2 dx (99) 5.3 The Universal Confining Layer (by P. Stone) An unrecognized protector of our ground water There is a unique geological unit economically critical, hydrologically essential, extremely widespread (ubiquitous among some investigated environments) that amazingly has not been formally recognized and described as an interrelated unit, and not named according to the rules for stratigraphic nomenclature. This unit, whose lithology and thickness varies among sites but is always highly impermeable, even when very thin, is found to lie atop the first usable drinking-water aquifer apparently virtually everywhere. Or, perhaps one should say, it is found in virtually every place where there has been some shallow stratigraphic and geo-hydrologic investigation that could reveal it; these of course being at sites where actual, or suspected, or potential, ground-water contamination has prompted such investigation. Surprisingly, this unit almost always perches some completely unconnected, sometimes ephemeral, always minor and inconsequential, zone or ground water atop it, that being the contaminated zone where present. Or else no water table whatsoever reportedly exists above the confining layer for the underlying aquifer in hydraulic nature even though it often occurs at an uncommonly shallow depth for such an aquifer. 25
26 This formation and confining layer is unique not only because of its near ubiquity among the widely scattered investigated sites, but because it encompasses various different geologic formations and, astoundingly, completely different geologic provinces also. What other geologic formation in the shallow subsurface encompasses both Appalachian Piedmont and Atlantic Coastal-Plain provinces, of vastly different ages and especially origins? Host materials range from soft sediments to residua from hard crystalline rocks (curiously, the same condition, if not the layer itself, is commonly reported for fractured hard-rock aquifers also). One might conjecture that this layer relates somehow to alluvial deposition, stream valleys certainly being one of the few depositional environments to span both Piedmont and Coastal-Plain geologic provinces. Or perhaps it is some unrecognized sub- C soil horizon or phenomenon, formed in-place. Will close examination of contamination-site investigations from other geologic provinces, in other parts of the country, reveal this same formation? Is it found still further afield, at least at sites where there is some exploratory interest able to find it? The economic importance of this stratum cannot be overestimated. By universally isolating the uppermost true aquifer from the host of dangerous materials at the ground surface above, or especially those dissolved in the shallowest perched or ephemeral ground water so nearby above, the environmental Cleanup costs that are avoided, or deemed unnecessary, are astronomical in their cumulative total, and represent some very considerable sum at any given site also. Other distinctive distributional characteristics include (I thank a colleague for this observation) the apparent tendency, judged from reported contaminant-plume geometry, for the confining unit to rise near property boundaries. Incidentally, I hope the identification of this physical mechanism lays to rest the suspicious sometimes voiced concerning the numerous ground-water contaminant plumes that seem never to migrate out from the responsible party s property to another s, ending instead somewhere near the boundary. The averted costs in liabilities add another vast value to this unit. One accepts as obvious that this geographic coincidence of property boundaries and 26
27 contaminant plumes and their controlling stratigraphy cannot be random coincidence and that property lines themselves cannot influence the underground. Could there in any way be some nonapparent control made by the underground environment on the boundaries? At first glance, of course, this would seem to be impossible. But perhaps it involves unknowing influence on decisions in platting, somewhat like the suspected subconscious reading of subtle topographic and other surficial signs by water witchers who then truly believe that they feel the divining rod move as they pass over an underground stream. What other reasonable explanation can there be for these fortuitously placed natural liners, and even natural slurry walls, containing the future spread of ground-water contaminants at the many sites that so desperately need them? How did the extremely widespread occurrence of this single stratum, or at least an analogous stratigraphic sequence, escape geologic investigation s attention prior to the proliferation of contamination-site hydrologic investigation? Dare one put forth an outrageous hypothesis? Could some action of the contaminants themselves create this layer, say perhaps by somehow chemically reducing permeability. What other physical or cultural characteristic of ground-water contamination, or of such sites, might cause or explain this prevailing presence? This remains as grist for future research. In any case, if this important zone exists almost everywhere and a host of apparently irrefutable professional sources have identified it at scores of sites it should be recognized and named formally, as are all significant geologic units no matter how emplaced. I have sought advice from colleagues regarding a descriptive or distinctive name for the layer or formation, with a diversity of suggestions received: From the artificial constructs Nofurac or Commonly Formations (no further action or continued monitoring only), to the Linnean binomial Confinus Maximus, to the Victorian-era-sounding The glorious [or great or grand ] hydraulic impedance. My personal favorite, and therefore the winner, is the Nocostus Aquitard, and thus it is given. 27
Hydraulic properties of porous media
PART 5 Hydraulic properties of porous media Porosity Definition: Void space: n V void /V total total porosity e V void /V solid Primary porosity - between grains Secondary porosity - fracture or solution
More informationGG655/CEE623 Groundwater Modeling. Aly I. El-Kadi
GG655/CEE63 Groundwater Modeling Model Theory Water Flow Aly I. El-Kadi Hydrogeology 1 Saline water in oceans = 97.% Ice caps and glaciers =.14% Groundwater = 0.61% Surface water = 0.009% Soil moisture
More informationSoils, Hydrogeology, and Aquifer Properties. Philip B. Bedient 2006 Rice University
Soils, Hydrogeology, and Aquifer Properties Philip B. Bedient 2006 Rice University Charbeneau, 2000. Basin Hydrologic Cycle Global Water Supply Distribution 3% of earth s water is fresh - 97% oceans 1%
More informationDarcy's Law. Laboratory 2 HWR 531/431
Darcy's Law Laboratory HWR 531/431-1 Introduction In 1856, Henry Darcy, a French hydraulic engineer, published a report in which he described a series of experiments he had performed in an attempt to quantify
More informationFinding Large Capacity Groundwater Supplies for Irrigation
Finding Large Capacity Groundwater Supplies for Irrigation December 14, 2012 Presented by: Michael L. Chapman, Jr., PG Irrigation Well Site Evaluation Background Investigation Identify Hydrogeologic Conditions
More informationHYDROGEOLOGICAL PROPERTIES OF THE UG2 PYROXENITE AQUIFERS OF THE BUSHVELD COMPLEX
R. Gebrekristos, P.Cheshire HYDROGEOLOGICAL PROPERTIES OF THE UG2 PYROXENITE AQUIFERS OF THE BUSHVELD COMPLEX R. Gebrekristos Digby Wells Environmental P. Cheshire Groundwater Monitoring Services Abstract
More informationdynamics of f luids in porous media
dynamics of f luids in porous media Jacob Bear Department of Civil Engineering Technion Israel Institute of Technology, Haifa DOVER PUBLICATIONS, INC. New York Contents Preface xvii CHAPTER 1 Introduction
More informationGroundwater Hydrology
EXERCISE 12 Groundwater Hydrology INTRODUCTION Groundwater is an important component of the hydrologic cycle. It feeds lakes, rivers, wetlands, and reservoirs; it supplies water for domestic, municipal,
More information' International Institute for Land Reclamation and Improvement. 2 Groundwater Investigations. N.A. de Ridder'? 2.1 Introduction. 2.
2 Groundwater Investigations N.A. de Ridder'? 2.1 Introduction Successful drainage depends largely on a proper diagnosis of the causes of the excess water. For this diagnosis, one must consider: climate,
More informationProf. Stephen A. Nelson EENS 111. Groundwater
Page 1 of 8 Prof. Stephen A. Nelson EENS 111 Tulane University Physical Geology This page last updated on 20-Oct-2003 is water that exists in the pore spaces and fractures in rock and sediment beneath
More informationGroundwater. (x 1000 km 3 /y) Oceans Cover >70% of Surface. Groundwater and the. Hydrologic Cycle
Chapter 17 Oceans Cover >70% of Surface Groundwater and the Hydrologic Cycle Vasey s Paradise, GCNP Oceans are only 0.025% of Mass Groundwater Groundwater is liquid water that lies in the subsurface in
More informationRADIONUCLIDE DIFFUSION IN GEOLOGICAL MEDIA
GEOPHYSICS RADIONUCLIDE DIFFUSION IN GEOLOGICAL MEDIA C. BUCUR 1, M. OLTEANU 1, M. PAVELESCU 2 1 Institute for Nuclear Research, Pitesti, Romania, crina.bucur@scn.ro 2 Academy of Scientists Bucharest,
More informationSurface Processes Focus on Mass Wasting (Chapter 10)
Surface Processes Focus on Mass Wasting (Chapter 10) 1. What is the distinction between weathering, mass wasting, and erosion? 2. What is the controlling force in mass wasting? What force provides resistance?
More informationEssentials of Geology, 11e
Essentials of Geology, 11e Groundwater Chapter 10 Instructor Jennifer Barson Spokane Falls Community College Geology 101 Stanley Hatfield Southwestern Illinois Co Jennifer Cole Northeastern University
More informationChapter 13. Groundwater
Chapter 13 Groundwater Introduction Groundwater is all subsurface water that completely fills the pores and other open spaces in rocks, sediments, and soil. Groundwater is responsible for forming beautiful
More informationRATE OF FLUID FLOW THROUGH POROUS MEDIA
RATE OF FLUID FLOW THROUGH POROUS MEDIA Submitted by Xu Ming Xin Kiong Min Yi Kimberly Yip Juen Chen Nicole A project presented to the Singapore Mathematical Society Essay Competition 2013 1 Abstract Fluid
More informationAdvanced Hydrology Prof. Dr. Ashu Jain Department of Civil Engineering Indian Institute of Technology, Kanpur. Lecture 6
Advanced Hydrology Prof. Dr. Ashu Jain Department of Civil Engineering Indian Institute of Technology, Kanpur Lecture 6 Good morning and welcome to the next lecture of this video course on Advanced Hydrology.
More informationq v = - K h = kg/ν units of velocity Darcy's Law: K = kρg/µ HYDRAULIC CONDUCTIVITY, K Proportionality constant in Darcy's Law
Darcy's Law: q v - K h HYDRAULIC CONDUCTIVITY, K m/s K kρg/µ kg/ν units of velocity Proportionality constant in Darcy's Law Property of both fluid and medium see D&S, p. 62 HYDRAULIC POTENTIAL (Φ): Φ g
More information(Refer Slide Time: 02:10)
Soil Mechanics Prof. B.V.S. Viswanathan Department of Civil Engineering Indian Institute of Technology, Bombay Lecture 24 Flow of water through soils-v Welcome to lecture five of flow of water through
More informationGroundwater. (x 1000 km 3 /y) Reservoirs. Oceans Cover >70% of Surface. Groundwater and the. Hydrologic Cycle
Chapter 13 Oceans Cover >70% of Surface Groundwater and the Hydrologic Cycle Oceans are only 0.025% of Mass Groundwater Groundwater is liquid water that lies in the subsurface in fractures in rocks and
More information18 Single vertical fractures
18 Single vertical fractures 18.1 Introduction If a well intersects a single vertical fracture, the aquifer s unsteady drawdown response to pumping differs significantly from that predicted by the Theis
More informationIntroduction to Well Hydraulics Fritz R. Fiedler
Introduction to Well Hydraulics Fritz R. Fiedler A well is a pipe placed in a drilled hole that has slots (screen) cut into it that allow water to enter the well, but keep the aquifer material out. A well
More informationLand subsidence due to groundwater withdrawal in Hanoi, Vietnam
Land Subsidence (Proceedings of the Fifth International Symposium on Land Subsidence, The Hague, October 1995). 1AHS Publ. no. 234, 1995. 55 Land subsidence due to groundwater withdrawal in Hanoi, Vietnam
More informationLecture 16 Groundwater:
Reading: Ch 6 Lecture 16 Groundwater: Today 1. Groundwater basics 2. inert tracers/dispersion 3. non-inert chemicals in the subsurface generic 4. non-inert chemicals in the subsurface inorganic ions Next
More informationDarcy s law in 3-D. K * xx K * yy K * zz
PART 7 Equations of flow Darcy s law in 3-D Specific discarge (vector) is calculated by multiplying te ydraulic conductivity (second-order tensor) by te ydraulic gradient (vector). We obtain a general
More information12 10 8 6 4 2 0 40-50 50-60 60-70 70-80 80-90 90-100 Fresh Water What we will cover The Hydrologic Cycle River systems Floods Groundwater Caves and Karst Topography Hot springs Distribution of water in
More information1.72, Groundwater Hydrology Prof. Charles Harvey Lecture Packet #5: Groundwater Flow Patterns. Local Flow System. Intermediate Flow System
1.72, Groundwater Hydrology Prof. Charles Harvey Lecture Packet #5: Groundwater Flow Patterns c Local Flow System 10,000 feet Intermediate Flow System Regional Flow System 20,000 feet Hydrologic section
More informationEnhanced Characterization of the Mississippi River Valley Alluvial Aquifer Using Surface Geophysical Methods
Photo by Shane Stocks, U.S. Geological Survey Enhanced Characterization of the Mississippi River Valley Alluvial Aquifer Using Surface Geophysical Methods Presented by Ryan F. Adams US Geological Survey
More informationIn all of the following equations, is the coefficient of permeability in the x direction, and is the hydraulic head.
Groundwater Seepage 1 Groundwater Seepage Simplified Steady State Fluid Flow The finite element method can be used to model both steady state and transient groundwater flow, and it has been used to incorporate
More informationDarcy s Law. Darcy s Law
Darcy s Law Last time Groundwater flow is in response to gradients of mechanical energy Three types Potential Kinetic Kinetic energy is usually not important in groundwater Elastic (compressional) Fluid
More information16 Rainfall on a Slope
Rainfall on a Slope 16-1 16 Rainfall on a Slope 16.1 Problem Statement In this example, the stability of a generic slope is analyzed for two successive rainfall events of increasing intensity and decreasing
More informationENCE 3610 Soil Mechanics. Site Exploration and Characterisation Field Exploration Methods
ENCE 3610 Soil Mechanics Site Exploration and Characterisation Field Exploration Methods Geotechnical Involvement in Project Phases Planning Design Alternatives Preparation of Detailed Plans Final Design
More informationAppendix D Fractured Rock Appendix
Appendix D Fractured Rock Appendix 1.0 Introduction The behavior of LNAPL in fractured bedrock is not necessarily intuitive and is not as easily described using the principles and techniques adopted for
More informationENVIRONMENTAL EFFECTS OF GROUNDWATER WITHDRAWAL IN SOUTH NYÍRSÉG
PhD thesis ENVIRONMENTAL EFFECTS OF GROUNDWATER WITHDRAWAL IN SOUTH NYÍRSÉG János Szanyi Szeged, 2004 ENVIRONMENTAL EFFECTS OF GROUNDWATER WITHDRAWAL IN SOUTH NYÍRSÉG Preliminaries, the aims of the dissertation
More informationChapter 14. Groundwater
Chapter 14 Groundwater Importance of groundwater! Groundwater is water found in the pores of soil and sediment, plus narrow fractures in bedrock! Groundwater is the largest reservoir of fresh water that
More informationWATER ON AND UNDER GROUND. Objectives. The Hydrologic Cycle
WATER ON AND UNDER GROUND Objectives Define and describe the hydrologic cycle. Identify the basic characteristics of streams. Define drainage basin. Describe how floods occur and what factors may make
More informationChapter 8 Fetter, Applied Hydrology 4 th Edition, Geology of Groundwater Occurrence
Chapter 8 Fetter, Applied Hydrology 4 th Edition, 2001 Geology of Groundwater Occurrence Figure 8.42. Alluvial Valleys ground-water region. Fetter, Applied Hydrology 4 th Edition, 2001 Fetter, Applied
More informationEvaluation of the hydraulic gradient at an island for low-level nuclear waste disposal
A New Focus on Groundwater Seawater Interactions (Proceedings of Symposium HS1001 at IUGG2007, Perugia, July 2007). IAHS Publ. 312, 2007. 237 Evaluation of the hydraulic gradient at an island for low-level
More informationThe use of straddle packer testing to hydraulically characterize rock boreholes for contaminant transport studies
The use of straddle packer testing to hydraulically characterize rock boreholes for contaminant transport studies Patryk Quinn, John Cherry, Beth Parker Presentation for the Solinst Symposium November
More informationFluid Mechanics II Viscosity and shear stresses
Fluid Mechanics II Viscosity and shear stresses Shear stresses in a Newtonian fluid A fluid at rest can not resist shearing forces. Under the action of such forces it deforms continuously, however small
More information11/22/2010. Groundwater in Unconsolidated Deposits. Alluvial (fluvial) deposits. - consist of gravel, sand, silt and clay
Groundwater in Unconsolidated Deposits Alluvial (fluvial) deposits - consist of gravel, sand, silt and clay - laid down by physical processes in rivers and flood plains - major sources for water supplies
More information*** ***! " " ) * % )!( & ' % # $. 0 1 %./ +, - 7 : %8% 9 ) 7 / ( * 7 : %8% 9 < ;14. " > /' ;-,=. / ١
١ ******!" #$ % & '!( ) % * ") +,-./ % 01. 3 ( 4 56 7/4 ) 8%9 % : 7 ;14 < 8%9 % : *7./ = ;-, >/'." Soil Permeability & Seepage ٢ Soil Permeability- Definition ٣ What is Permeability? Permeability is the
More informationTable of Contents Chapter 1 Introduction to Geotechnical Engineering 1.1 Geotechnical Engineering 1.2 The Unique Nature of Soil and Rock Materials
Table of Contents Chapter 1 Introduction to Geotechnical Engineering 1.1 Geotechnical Engineering 1.2 The Unique Nature of Soil and Rock Materials 1.3 Scope of This Book 1.4 Historical Development of Geotechnical
More informationInstructor : Dr. Jehad Hamad. Chapter (7)
Instructor : Dr. Jehad Hamad Chapter (7) 2017-2016 Soil Properties Physical Properties Mechanical Properties Gradation and Structure Compressibility Soil-Water Relationships Shear Strength Bearing Capacity
More informationSTUDY GUIDE FOR CONTENT MASTERY. Movement and Storage of Groundwater
Groundwater SECTION 10.1 Movement and Storage of Groundwater In your textbook, read about the hydrosphere, precipitation and groundwater, and groundwater storage. Use the following terms to complete the
More informationDATA ACQUISITION METHODS FOR GROUNDWATER INVESTIGATION AND THE SITING OF WATER SUPPLY WELLS
DATA ACQUISITION METHODS FOR GROUNDWATER INVESTIGATION AND THE SITING OF WATER SUPPLY WELLS M.B.J. Foster Tetra Tech EM Inc., San Francisco, CA, USA Keywords: Groundwater, water wells, drilled wells, geophysical
More informationAPPENDIX Tidally induced groundwater circulation in an unconfined coastal aquifer modeled with a Hele-Shaw cell
APPENDIX Tidally induced groundwater circulation in an unconfined coastal aquifer modeled with a Hele-Shaw cell AaronJ.Mango* Mark W. Schmeeckle* David Jon Furbish* Department of Geological Sciences, Florida
More informationChapter 14: Groundwater. Fig 14.5b
Chapter 14: Groundwater Fig 14.5b OBJECTIVES Recognize that groundwater is a vital source of accessible freshwater. Describe how groundwater forms below the water table. Explain the origin of aquifers,
More informationEVALUATION OF AQUIFER CHARACTERISTICS FOR SELECTED NEW METHOD OF THE UM RUWABA FORMATION: NORTH KORDOFAN STATE, SUDAN
EVALUATION OF AQUIFER CHARACTERISTICS FOR SELECTED NEW METHOD OF THE UM RUWABA FORMATION: NORTH KORDOFAN STATE, SUDAN ELHAGA.B *1; ELZIENS.M*2 ANDLISSANN.H*3 *1Department of C i v i l E n g i n e e r i
More informationQuantifying shallow subsurface flow and salt transport in the Canadian Prairies
Quantifying shallow subsurface flow and salt transport in the Canadian Prairies Andrew Ireson GIWS, University of Saskatchewan www.usask.ca/water Uri Nachshon Garth van der Kamp GIWS, University of Saskatchewan
More informationGeophysics for Environmental and Geotechnical Applications
Geophysics for Environmental and Geotechnical Applications Dr. Katherine Grote University of Wisconsin Eau Claire Why Use Geophysics? Improve the quality of site characterization (higher resolution and
More information1.72, Groundwater Hydrology Prof. Charles Harvey Lecture Packet #4: Continuity and Flow Nets
1.7, Groundwater Hydrology Prof. Charles Harvey Lecture Packet #4: Continuity and Flow Nets Equation of Continuity Our equations of hydrogeology are a combination of o Conservation of mass o Some empirical
More informationKOZENY-CARMAN EQUATION REVISITED. Jack Dvorkin Abstract
KOZENY-CARMAN EQUATION REVISITED Jack Dvorkin -- 009 Abstract The Kozeny-Carman equation is often presented as permeability versus porosity, grain size, and tortuosity. When it is used to estimate permeability
More informationPermeability in Soils
Permeability in Soils Contents: Darcy s law- assumption and validity, coefficient of permeability and its determination (laboratory and field), factors affecting permeability, permeability of stratified
More informationTurbulence is a ubiquitous phenomenon in environmental fluid mechanics that dramatically affects flow structure and mixing.
Turbulence is a ubiquitous phenomenon in environmental fluid mechanics that dramatically affects flow structure and mixing. Thus, it is very important to form both a conceptual understanding and a quantitative
More informationMechanical Energy. Kinetic Energy. Gravitational Potential Energy
Mechanical Energy Kinetic Energy E k = 1 2 mv2 where E k is energy (kg-m 2 /s 2 ) v is velocity (m/s) Gravitational Potential Energy E g = W = mgz where w is work (kg-m 2 /s 2 ) m is mass (kg) z is elevation
More informationRiver Processes. Drainage Basin Morphometry
Drainage Basin Morphometry River Processes Morphometry - the measurement and mathematical analysis of the configuration of the earth s surface and of the shape and dimensions of its landforms. Horton (1945)
More informationEvaluation of Subsurface Formation of Pabna District, Bangladesh
IOSR Journal of Applied Geology and Geophysics (IOSR-JAGG) e-issn: 2321 0990, p-issn: 2321 0982.Volume 1, Issue 4 (Sep. Oct. 2013), PP 30-36 Evaluation of Subsurface Formation of Pabna District, Bangladesh
More informationEach basin is surrounded & defined by a drainage divide (high point from which water flows away) Channel initiation
DRAINAGE BASINS A drainage basin or watershed is defined from a downstream point, working upstream, to include all of the hillslope & channel areas which drain to that point Each basin is surrounded &
More informationAll soils in natural are permeable materials, water being free to flow through the interconnected pores between the solid particles.
8.1 Introduction Among construction materials, soil is very unique. Because of a relatively large space of void in its constituent, water can flow through soil. The water flow (seepage) characteristics
More informationProf. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
13 Permeability and Seepage -2 Conditions favourable for the formation quick sand Quick sand is not a type of sand but a flow condition occurring within a cohesion-less soil when its effective stress is
More informationSASKATCHEWAN STRATIGRAPHY GLACIAL EXAMPLE BOULDERS IN GLACIAL DEPOSITS
SASKATCHEWAN STRATIGRAPHY GLACIAL EXAMPLE BOULDERS IN GLACIAL DEPOSITS 51 SASKATCHEWAN STRATIGRAPHY GLACIAL SURFICIAL STRATIFIED DEPOSITS 52 SASKATCHEWAN STRATIGRAPHY GLACIAL EXAMPLE OF SEDIMENT DEPOSITION
More information2. FLUID-FLOW EQUATIONS SPRING 2019
2. FLUID-FLOW EQUATIONS SPRING 2019 2.1 Introduction 2.2 Conservative differential equations 2.3 Non-conservative differential equations 2.4 Non-dimensionalisation Summary Examples 2.1 Introduction Fluid
More information12 SWAT USER S MANUAL, VERSION 98.1
12 SWAT USER S MANUAL, VERSION 98.1 CANOPY STORAGE. Canopy storage is the water intercepted by vegetative surfaces (the canopy) where it is held and made available for evaporation. When using the curve
More informationWisconsin s Hydrogeology: an overview
2012 Soil and Water Conservation Society Conference Stevens Point, WI Feb 9, 2012 Wisconsin s Hydrogeology: an overview Ken Bradbury Wisconsin Geological and Natural History Survey University of Wisconsin-Extension
More informationTime Rate of Consolidation Settlement
Time Rate of Consolidation Settlement We know how to evaluate total settlement of primary consolidation S c which will take place in a certain clay layer. However this settlement usually takes place over
More informationTable 5-1 Sampling Program Summary for Milltown Ford Avenue Redevelopment Area, NJ.
Table 5- Sampling Program Summary for Milltown Ford Avenue Redevelopment Area, NJ. Transformer Pads (9 pads: PAD 9) Evaluate if PCBs presently exist in soils adjacent to, and/or beneath the transformer
More informationChapter 9: Differential Analysis
9-1 Introduction 9-2 Conservation of Mass 9-3 The Stream Function 9-4 Conservation of Linear Momentum 9-5 Navier Stokes Equation 9-6 Differential Analysis Problems Recall 9-1 Introduction (1) Chap 5: Control
More informationDeep Borehole Disposal Performance Assessment and Criteria for Site Selection
Deep Borehole Disposal Performance Assessment and Criteria for Site Selection Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department
More information1.5 Permeability Tests
1-17 1.5 Permeability Tests 1.5.1 General - To determine the coefficient of permeability(or coefficient of hydraulic conductivity) k - General method for determining k directly. 1) Constant-head method
More informationCE 240 Soil Mechanics & Foundations Lecture 5.2. Permeability III (Das, Ch. 6) Summary Soil Index Properties (Das, Ch. 2-6)
CE 40 Soil Mechanics & Foundations Lecture 5. Permeability III (Das, Ch. 6) Summary Soil Index Properties (Das, Ch. -6) Outline of this Lecture 1. Getting the in situ hydraulic conductivity 1.1 pumping
More informationMark S. Nordberg Geology and Groundwater Investigations Section North Central Region Office California Department of Water Resources
Mark S. Nordberg Geology and Groundwater Investigations Section North Central Region Office California Department of Water Resources Ukiah Drought Workshop July 29, 2009 Groundwater 101 Groundwater is
More informationCHAPTER 7 SEVERAL FORMS OF THE EQUATIONS OF MOTION
CHAPTER 7 SEVERAL FORMS OF THE EQUATIONS OF MOTION 7.1 THE NAVIER-STOKES EQUATIONS Under the assumption of a Newtonian stress-rate-of-strain constitutive equation and a linear, thermally conductive medium,
More informationLecture Outlines PowerPoint. Chapter 5 Earth Science 11e Tarbuck/Lutgens
Lecture Outlines PowerPoint Chapter 5 Earth Science 11e Tarbuck/Lutgens 2006 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors
More informationFUNDAMENTALS OF ENGINEERING GEOLOGY
FUNDAMENTALS OF ENGINEERING GEOLOGY Prof. Dr. HUSSEIN HAMEED KARIM Building and Construction Engineering Department 2012 Preface The impulse to write this book stemmed from a course of geology given by
More informationSafety assessment for disposal of hazardous waste in abandoned underground mines
Safety assessment for disposal of hazardous waste in abandoned underground mines A. Peratta & V. Popov Wessex Institute of Technology, Southampton, UK Abstract Disposal of hazardous chemical waste in abandoned
More informationDavid de Courcy-Bower and Samuel Mohr
Applicability and Limitations of LNAPL Transmissivity as a Metric within Bedrock Formations Insert then choose Picture select your picture. Right click your picture and Send to back. David de Courcy-Bower
More informationChapter 7 Permeability and Seepage
Permeability and Seepage - N. Sivakugan (2005) 1 7.1 INTRODUCTION Chapter 7 Permeability and Seepage Permeability, as the name implies (ability to permeate), is a measure of how easily a fluid can flow
More informationFundamentals of Fluid Dynamics: Elementary Viscous Flow
Fundamentals of Fluid Dynamics: Elementary Viscous Flow Introductory Course on Multiphysics Modelling TOMASZ G. ZIELIŃSKI bluebox.ippt.pan.pl/ tzielins/ Institute of Fundamental Technological Research
More information7. Basics of Turbulent Flow Figure 1.
1 7. Basics of Turbulent Flow Whether a flow is laminar or turbulent depends of the relative importance of fluid friction (viscosity) and flow inertia. The ratio of inertial to viscous forces is the Reynolds
More informationIntroduction to Marine Hydrodynamics
1896 1920 1987 2006 Introduction to Marine Hydrodynamics (NA235) Department of Naval Architecture and Ocean Engineering School of Naval Architecture, Ocean & Civil Engineering First Assignment The first
More informationLand subsidence due to groundwater withdrawal from the semi-confined aquifers of southwestern Flanders
Land Subsidence (Proceedings of the Fifth International Symposium on Land Subsidence, The Hague, October 1995). IAHS Publ. no. 234, 1995. 47 Land subsidence due to groundwater withdrawal from the semi-confined
More informationModelling of dispersed, multicomponent, multiphase flows in resource industries. Section 3: Examples of analyses conducted for Newtonian fluids
Modelling of dispersed, multicomponent, multiphase flows in resource industries Section 3: Examples of analyses conducted for Newtonian fluids Globex Julmester 017 Lecture # 04 July 017 Agenda Lecture
More informationA Simple Data Analysis Method for a Pumping Test with the Skin and Wellbore Storage Effects
A Simple Data Analysis Method for a Pumping Test with the Skin and Wellbore Storage Effects Reporter: Chuan-Gui Lan Professor: Chia-Shyun Chen Date: 2008/05/22 Introduction The pumping test is commonly
More informationWhat we will cover. The Hydrologic Cycle. River systems. Floods. Groundwater. Caves and Karst Topography. Hot springs
Fresh Water What we will cover The Hydrologic Cycle River systems Floods Groundwater Caves and Karst Topography Hot springs On a piece of paper, put these reservoirs of water in to order from largest to
More informationψ ae is equal to the height of the capillary rise in the soil. Ranges from about 10mm for gravel to 1.5m for silt to several meters for clay.
Contents 1 Infiltration 1 1a Hydrologic soil horizons...................... 1 1b Infiltration Process......................... 2 1c Measurement............................ 2 1d Richard s Equation.........................
More informationDNAPL migration through interbedded clay-sand sequences
Groundwater Quality: Natural and Enhanced Restoration of Groundwater Pollution (Proceedings ofthe Groundwater Quality 2001 Conference held al Sheffield. UK. June 2001). IAHS Publ. no. 275. 2002. 455 DNAPL
More informationThe Realm of Hydrogeology
The Real of Hydrogeology In class exercise Stagnant Flow Plot hydraulic head and ressure vs. deth for (also indicate the hydrostatic line) Stagnant flow (no flow) Steady downward flow Steady uward flow
More informationLesson 6 Review of fundamentals: Fluid flow
Lesson 6 Review of fundamentals: Fluid flow The specific objective of this lesson is to conduct a brief review of the fundamentals of fluid flow and present: A general equation for conservation of mass
More informationHeat and Mass Transfer Prof. S.P. Sukhatme Department of Mechanical Engineering Indian Institute of Technology, Bombay
Heat and Mass Transfer Prof. S.P. Sukhatme Department of Mechanical Engineering Indian Institute of Technology, Bombay Lecture No. 18 Forced Convection-1 Welcome. We now begin our study of forced convection
More informationChapter 1 Fluid Characteristics
Chapter 1 Fluid Characteristics 1.1 Introduction 1.1.1 Phases Solid increasing increasing spacing and intermolecular liquid latitude of cohesive Fluid gas (vapor) molecular force plasma motion 1.1.2 Fluidity
More informationDetermining In Situ Properties of Claystone Aquitards Using Pore Pressure Responses from Grouted-in Pressure Transducers
Determining In Situ Properties of Claystone Aquitards Using Pore Pressure Responses from Grouted-in Pressure Transducers Laura A. Smith, S. Lee Barbour, M. Jim Hendry University of Saskatchewan, Saskatoon,
More informationChapter 9: Differential Analysis of Fluid Flow
of Fluid Flow Objectives 1. Understand how the differential equations of mass and momentum conservation are derived. 2. Calculate the stream function and pressure field, and plot streamlines for a known
More informationHEAT TRANSFER IN A LOW ENTHALPY GEOTHERMAL WELL
HEAT TRANSFER IN A LOW ENTHALPY GEOTHERMAL WELL Marcel Rosca University of Oradea, Armata Romana 5, RO-37 Oradea, Romania Key Words: low enthalpy, numerical modeling, wellbore heat transfer, Oradea reservoir,
More informationEvolution of the conceptual hydrogeologic and ground-water flow model for Las Vegas Valley, Clark County, Nevada
Evolution of the conceptual hydrogeologic and ground-water flow model for Las Vegas Valley, Clark County, Nevada Geological Society of America Annual Meeting November 14, 2 David J. Donovan Southern Nevada
More information1. Water in Soils: Infiltration and Redistribution
Contents 1 Water in Soils: Infiltration and Redistribution 1 1a Material Properties of Soil..................... 2 1b Soil Water Flow........................... 4 i Incorporating K - θ and ψ - θ Relations
More informationAn Hypothesis Concerning a Confined Groundwater Zone in Slopes of Weathered Igneous Rocks
Symposium on Slope Hazards and Their Prevention: 8-10 May, 2000, Hong Kong, PRC An Hypothesis Concerning a Confined Groundwater Zone in Slopes of Weathered Igneous Rocks J. J. Jiao and A. W. Malone Department
More informationChapter 12 Subsurface Exploration
Page 12 1 Chapter 12 Subsurface Exploration 1. The process of identifying the layers of deposits that underlie a proposed structure and their physical characteristics is generally referred to as (a) subsurface
More informationEVALUATING HEAT FLOW AS A TOOL FOR ASSESSING GEOTHERMAL RESOURCES
PROCEEDINGS, Thirtieth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, January 31-February 2, 2005 SGP-TR-176 EVALUATING HEAT FLOW AS A TOOL FOR ASSESSING GEOTHERMAL
More informationHydraulic and Water-Quality Characterization of Fractured-Rock Aquifers Using Borehole Geophysics
Hydraulic and Water-Quality Characterization of Fractured-Rock Aquifers Using Borehole Geophysics John H. Williams Office of Ground Water Troy, New York Flow in Open Borehole Runkel and others (2003) Ambient
More information