Jacob, and chow methods are discussed in detail, showing data of a 6. Use of the theis equation to determine t and s from a pumping test matching the wu curve on a loglog plot s vsr2t. Aquifertest for windows pumping test and slug test. Unfortunately, an analytical solution for the equations is involved and a graphical solution is commonly used instead. Thirty years after theim equation was derived, theis published the following solution sr. This course introduces the basic equations ofthis course introduces the basic equations of groundwater flow, the analytical techniques that havegroundwater flow, the analytical techniques that have been developed to solve these equations, and theirbeen developed to solve these equations, and their practical implementation in pumping test. For example, equations used in data analysis incorporate the radii of the well and borehole. Using equations 2a, 2b and 3 with timedrawdown data from an aquifer test, s and t for the aquifer can be calculated. The total number of pumping tests on record in the survey files through 1954 is 1,321. Methods of determining permeability, transmissibility and drawdown.
Identify pumping well and observation wells and their conditions e. We demonstrate that values of transmissivity compare well between the different types of tests for each lithology, when the scale of the test is similar. Theis 1935 gave an expression for 107 drawdown due to pumping a well at rate qin a homogeneous, isotropic con. Hydraulic conductivity and storage coefficient of aquifers are often estimated from nonequilibrium well pumping test data using theis method. Aquifertest for windows is the first pumping test and slug test analysis software package to combine an intuitive and intelligent windows interface for convenient data entry with graphical data analysis tools and reportquality graphical output capabilities. Improved characterization of small u for jacob pumping. Well hydraulics the time required to reach steady state depends on. Thus, to minimize u, r should be small and t should be. Partial penetration, superposition, and bounded aquifers the use of wellz. Principle of pumping test the principle of a pumping test involves applying a stress to an aquifer by extracting groundwater from a pumping well and measuring the aquifer response to that stress by monitoring drawdown as a function of time. The theis equation, which was derived from the analogy between the flow of groundwater and the conduction of heat, is written as sr,t.
An excel tool for teaching theis method of estimating aquifer parameters navaratnam leelaruban1. Theis 1935hantush 1964 pumping test solution for nonleaky. The illinois state water survey has used the method. The theis equation, which was derived from the analogy between the flow. The texas water development board developed the following interactive tools to assist interested parties in understanding the effects of pumping at select locations where aquifer properties are either known or can be estimated with a certain degree of certainty.
An analysis procedure is presented with each method, so that the. Theis 1935 pumping test solution for unconfined aquifers. Theis equation example texas water development board. Accounting for the influence of aquifer heterogeneity on. Conventional pumping test interpretation techniques generally rely on the theis equation theis, 1935 which combines darcys. The pump ing causes a dewatering of the aquifer and creates a cone of depression in the water table. Recent advances in aquifer test interpretation incorporate derivative analysis to improve the reliability of the cooper and jacob matching procedure. T is the transmissivity, and t is the time since beginning of pumping. Theis found the nonsteady flow of groundwater to be analagous to the unsteady flow of heat in a homogeneous solid. Technical guidance manual for ground water investigations. A5 summary of results of analysis of pumping test data from. The equation describes mass conservation of groundwater flow in the radial direction allowing for change in storage volume expansion or contraction of the confined water due to change in pressure. Recovery data can be used if pumping rate varied considerably during the test. Theis 1935 published the first analysis of transient pump test for o constant pumping.
An evaluation of jacobs method for the interpretation of. Comparisons of the results between the proposed method and graphical methods including the theis, cooper. Equation conservation of mass unsteady groundwater flow to a pumping well in a confined aquifer is described by the equation bear, 1979, p. An excel tool for teaching theis method of estimating. In this laboratory exercise, the thiem 1906, theis 1935 and jacob 1946 equations are employed. Analysis and evaluation of pumping test data hydrology. Constant rate gridley walton 1962 presented data from a pumping test conducted on july 2, 1953 near gridley, illinois. Pdf hydraulic conductivity and storage coefficient of aquifers are often estimated from nonequilibrium well pumping test data using theis method. Estimating the reliability of aquifer transmissivity. Constant rate pumping tests are most often interpreted using the theis 1935 method or jacobs semilogarithmic approximation cooper and. Each spreadsheet incorporates analytical solutions of the partial differential equation for groundwater flow to a well for a specific type of condition or aquifer. The nature of the materials comprising the screened interval i.
Direct propagation of probability density functions in. Most commonly an aquifer test is conducted by pumping water from one well at a steady rate and for at least one day, while carefully measuring the water levels in the monitoring wells. Groundwater hydrologists commonly refer to the integral in 1 as the theis well function, abbreviated as. We also have online sales of a wide range of groundwater sampling equipment including ysi 556, and solinst levelogger including software such as modflow, rbca tool kit.
Jacob and theis methods were applied as more or less standard procedure and. Aquifer pumping tests 93 the solution of equation 1 is theis, 1935 where u defined as is called similarity variable, and wu is called theis well function in hydrology tabulated in hydrogeology books. Well losses often important, so drawdown in the pumping well often not useful during pumping. Theis equation calculation for aquifer testing and well drawdown last revision. Perform pumping test time drawdown calculations online. When water is pumped from the pumping well the pressure in the aquifer that feeds that well declines. For more details, please see see pumping test methods finally, the following test is available for analyzing well performance specific capacity test hantushbierschenk well losses well efficiency slug or bail tests, where a slug is.
Partially penetrating wells, theiss recovery method. It has been previously observed that during a pumping test in heterogeneous me dia, drawdown data from. The theis equation has become the most widely used equation in transient groundwater hydraulics and the solution in terms of drawdown is where drawdown at distancer at time t after the start of pumping l q discharge rate. The test well well 3 fully penetrated an 18ft thick sand and gravel aquifer under nonleaky artesian conditions. A simplified solution using izbashs equation for non. Spreadsheets for solving groundwater flow and pollution probl.
Placed less focus on workplans and more on what and how pump and slug test data should be submitted. The results are compared with short and longduration pumping tests performed throughout the region. Through the years the theis equation has played an important role in ground. Hydrogeologists have to rely on an interpretation model for the evaluation of pumping test data. These measurements are then incorporated into an appropriate wellflow equation to calculate the. As pumping continues, the cone expands and deepens, and the. Q, theis equation for drawdown the above equation is known as theis matching curve by plotting field data obtained during pumping test on type curve using the same scale on semilogarithmic paper, then the two curves superimposed on each other the unknown values can be obtained to calculate the aquifer parameters. This method requires matching a typecurve with time. Pumping test to determine k solve equation 6 for k. Radial flow to a well in a horizontal confined aquifer freeze and cherry, 1979 analytical solution the analytical solution of the drawdown as a function of time and distance is expressed by equation 1. Mod01 lec15 unsteady radial flow in leaky aquifers contd. Evaluation of methods of pumping test analyses for application to hawaiian aquifers by john a. Theis equation calculation for aquifer testing and well.
In theory, because the pumped water must come from a reduction of storage within the aquifer, only. Spreadsheets for the analysis of aquifertest and slug. The theis equation for flow to a fully penetrating line sink discharging at a constant rate in a homogeneous, isotropic and nonleaky confined aquifer of infinite extent is as follows. Theory and analysis methods pumping test analysis methods fixed assumptions when the pump is shut down after a pumping test, the water level inside the pumping and observation wells will start to rise. This spreadsheet automatically fit the theis equation to a pumping test. Compare this to the value calculated using the theis method 1. Theis 1935 presented an exact analytical solution for the transient drawdown in an infinite uniform confined aquifer see fig 1.
Partial penetration, superposition, and bounded aquifers. Confined aquifer pumping test analysis waterloo hydrogeologic. The users manual button will display a pdf document of the manual, which requires. Pdf pumping tests are used to determine the transmissivities and storage coefficients of aquifers. An aquifer test or a pumping test is conducted to evaluate an aquifer by stimulating the aquifer through constant pumping, and observing the aquifers response drawdown in observation wells. Pumping continued for eight hours at a constant rate of 220 gallonsperminute gpm. Pdf an excel tool for teaching theis method of estimating. This report documents several spreadsheets that have been developed for the analysis of aquifer pumping test and slug test data. Analysis with the theis method is performed by matching the theis type curve to drawdown data plotted as a function of time on double.
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