Kris Kuhlman's Hydrogeophysics Research

Publications

Citation indexes: Google, OSTI, and ORCiD.

Software is free for use and redistribution via the MIT license. If you cannot compile or run the program yourself, I may be able to help you compile it or set up the right environment to get it working.

Most of this software, and various other publically available git repositories with sofwtare are found on bitbucket or github under my username.

(github) · Laplace Transform Analytic Element Method
A Fortran03 program implementing the LT-AEM for circular (including wells as a special case) and elliptical elements (including lines as a special case), used in Bakker & Kuhlman (2011), my dissertation, and Kuhlman & Neuman (2009). This includes an implementation of the same modified Mathieu library also given as a stand-alone Python library below.
(github) · Unconfined Well Test Simulator
A Fortran03 program implementing the major unconfined well test solutions (Neuman, 1972; Neuman, 1974; Moench, 1995; Moench, 2001; Mishra & Neuman, 2010; Mishra & Neuman, 2011; Malama, 2011), and special degenerate cases (Theis, 1935; Hantush, 1961). The program executes in parallel on multiple processors using OpenMP. It can compute a time-series solution at a point (including the derivative) or a contour map of drawdown in space at a given time. The git repository also includes data from three large-scale unconfined pumping tests.
(bitbucket-2015, github-2024) · Multiporosity Well Test Simulator
A Fortran03 program implementing a radially symmetric solution to the multiporosity governing equations (Kuhlman et al., 2015). The multiporosity solution is a generalization of dual-porosity flow in low-permeability fractured rocks. The distribution of a potentially infinite number of porosities (i.e., an extension of double or triple porosity) degenerates to multiple published solutions (Warren & Root, 1963; Kazemi, 1969; Clossman, 1975). The multiporosity solution is the logical combination of the multirate solute transport solution of Haggerty & Gorelick (1995) with the double-porosity pressure-driven well test solution of Warren & Root. The update to this (Kuhlman, 2024) has a closed-form solution for the infinite series to represent the diffusion-in-the-matrix solution, and is available on github.
(bitbucket) · Moving Water Table Unconfined Slug Test Solution
A Fortran90 program implementing the unconfined (MWT solution of Neuman 1972) slug test solution, which accounts for linearized momentum balance in the slug test interval (i.e., oscillating slug responses) discussed in Malama et al. (2011), and includes the extensions for predicting drawdown during cross-hole slug tests, as discussed in Malama et al. (2016). This program computes the double numerical inverse Laplace and Hankel transforms (infinite Hankel transform in 2011 solution, and finite Hankel transform in 2016 solution) to compute the time-domain solution given in the paper.

NB: The extended or unified Hyder solution from Malama et al. (2011) (which extended the confined Hyder solution to unconfined conditions with a constant head boundary at the water table) is a MATLAB/Octave script that is also available.
(ZIP, DIR) · Leaky-unconfined Aquifer Flow Solution
A Fortran90 program for computing the leaky-unconfined solutions discussed in Malama, Kuhlman & Barrash (2007; 2008). This program does the double numerical inverse Laplace and Hankel transforms required to compute the time-domain solutions given in the papers.
(ZIP, DIR, bitbucket) · Electrokinetic Pumping Test Voltage Solution
A Fortran90 program for computing the electrokinetic response from pumping a well in an unconfined system, as discussed in Malama et al. (2009a; 2009b). The numerical Laplace inverse transform uses the Stehfest algorithm, while a combination of tanh-sinh quadrature and accelerated Gauss-Lobatto quadrature (between the zeros of the J₀ Bessel function) is used for the numerical Hankel inverse transform. These algorithms are much faster and more accurate than the algorithms used in the leaky-unconfined papers listed above.
(ZIP, DIR) · Steady Unsaturated Flow from an Elliptical Pipe
A set of MATLAB/Octave scripts for computing Quasilinear infiltration solutions to Richards' equation from Kuhlman & Warrick (2008). These scripts compute the required ratios of Mathieu functions, compute the solution, and plot the figures shown in the paper.
(ZIP, DIR, bitbucket) · Modified Mathieu Functions of Complex Parameter
A Python module for computing both angular and radial modified Mathieu functions (and their derivatives with respect to argument) of integer order and general complex Mathieu parameter (Re(q)<0), see a pdf summary of Mathieu function library output, and a numerical comparison to a published C++ Mathieu function library for real q (Alhargan, 2000). The Python module rvequires numpy and scipy. This same functionality is also implemented in Fortran in my LT-AEM program available above.
(ZIP, DIR) · Cokriging Hydraulic Heads with Boundary Conditions
A set of MATLAB/Octave scripts for cokriging heads taking boundary conditions into account, without requiring the user to explicitly come up with the cross-variograms, since they are given explicitly by the physics of the problem (Kuhlman & Pardo-Igúzquiza, 2010). These scripts set up and solve the cokriging equations using either the true derivative or finite-difference approximations and can make all the figures and examples given in the paper.
(github, DOI) · Numerical Inverse Laplace Transform in Python
I contributed numerical inverse Laplace transform functionality to the Python-based multiprecition library mpmath, specifically the de Hoog, Knight & Stokes, Stehfest, and fixed Talbot algorithms. The documentation for this feature gives more details regarding the capabilities, limitations, and some simple test cases. These same three algorithms are also available in a bitbucket repository that includes a numpy/scipy version of the mpmath library, but using fixed precision.

Kris Kuhlman's Hydrogeophysics Research

Publications

Primary Publications (Journal articles & Book chapters)

Peer-Reviewed Conference Papers

Select Technical Reports

Conference Presentation or Poster without Paper

Software