![]() In the case of a piezometer, the following equation applies: s = Q 4 π T [ w u, r / B + 2 b π l - d ∑ n = 1 ∞ 1 n ( sin n π l b - sin n π d b ) Hantush ( 1961a, b) derived equations which extend the Hantush and Jacob method to include partially penetration effects in a leaky confined aquifer. Note that Kruseman and de Ridder (1994) refer to the Hantush and Jacob curve-fitting procedure as Walton's method ( Walton 1962) and use the symbol w(u,r/L) to represent the Hantush and Jacob well function for leaky confined aquifers.Ī partially penetrating pumping well produces vertical components of flow in the pumped aquifer. Therefore, we may write the Hantush and Jacob equation in compact notation as follows: s = Q 4 π T w ( u, r / B ) (4) Groundwater hydrologists commonly refer to the integral in the Hantush and Jacob solution (Equation 1) as the Hantush and Jacob well function for leaky confined aquifers, abbreviated as w(u,r/B). t is elapsed time since start of pumping.r is radial distance from pumping well to observation well.K ′ is vertical hydraulic conductivity of the aquitard.Their mathematical equation for flow to a fully penetrating line sink discharging at a constant rate in a homogeneous, isotropic and leaky confined aquifer of infinite extent is as follows: s = Q 4 π T ∫ u ∞ e - y - r 2 / 4 B 2 y y dy (1) u = r 2 S 4 T t (2) B = T b ′ K ′ (3) Hantush (1921-1984) and Charles Edward Jacob (1914-1970) developed the first rigorous mathematical model of transient flow of water to a pumping well in a leaky confined aquifer. aquitards are incompressible (no storage).aquitards are overlain or underlain by an infinite constant-head plane source.aquitards have infinite areal extent, uniform vertical hydraulic conductivity and uniform thickness.diameter of control well is very small so that storage in the well can be neglected.water is released instantaneously from storage with decline of hydraulic head.flow to control well is horizontal when control well is fully penetrating.control well is fully or partially penetrating.aquifer is homogeneous, isotropic and of uniform thickness.AQTESOLV incorporates the principle of superposition in time to simulate variable-rate and recovery tests with this method. You are not restricted to constant-rate tests with the Hantush and Jacob solution. The solution assumes no storage in incompressible leaky aquitard(s) and can account for partially penetrating wells ( Hantush 1961a,b). A mathematical solution by Hantush and Jacob (1955) is useful for determining the hydraulic properties (transmissivity and storativity of pumped aquifer vertical hydraulic conductivity of aquitard) of leaky confined (semi-confined) aquifers.Īnalysis involves matching the Hantush-Jacob w(u,r/B) well function for leaky confined aquifers to drawdown data collected during a pumping test (aquifer test). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |