Drawdown Cone Volume of Pumping Well in Non-Leaky Confined Aquifer

2011 ◽  
Vol 356-360 ◽  
pp. 1211-1214
Author(s):  
Jian Min Yang ◽  
Jun Jie Han

Drawdown cone volume of pumping well reflects the hydro geological conditions of aquifer, such as hydraulic parameters and elastic storage for confined aquifer. During later period of pumping test in non-leaky confined aquifer, the relationship between drawdown and distance appears as straight line in plots figure, and the relationship between drawdown and time appears as straight line in plots figure. Based on Theis solution, through analyzing of the slope of curves , and integrating, volume of drawdown cone of pumping well in non-leaky confined aquifer was derived in this paper.

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1657
Author(s):  
Jingzhou Zhang ◽  
Shengtang Zhang ◽  
Si Chen ◽  
Ming Liu ◽  
Xuefeng Xu ◽  
...  

To explore the characteristics of overland flow resistance under the condition of sparse vegetative stem coverage and improve the basic theoretical research of overland flow, the resistance characteristics of overland flow were systematically investigated under four slope gradients (S), seven flow discharges (Q), and six degrees of vegetation coverage (Cr). The results show that the Manning roughness coefficient (n) changes with the ratio of water depth to vegetation height (h/hv) while the Reynolds number (Re), Froude number (Fr), and slope (S) are closely related to vegetation coverage. Meanwhile, h/hv, Re, and Cr have strong positive correlations with n, while Fr and S have strong negative correlations with n. Through data regression analysis, a power function relationship between n and hydraulic parameters was observed and sensitivity analysis was performed. It was concluded that the relationship between n and h/hv, Re, Cr, Q, and S shows the same law; in particular, for sparse stem vegetation coverage, Cr is the dominant factor affecting overland flow resistance under zero slope condition, while Cr is no longer the first dominant factor affecting overland flow resistance under non-zero slope condition. In the relationship between n and Fr, Cr has the least effect on overland flow resistance. This indicates that when Manning roughness coefficient is correlated with different hydraulic parameters, the same vegetation coverage has different effects on overland flow resistance. Therefore, it is necessary to study overland flow resistance under the condition of sparse stalk vegetation coverage.


2018 ◽  
Author(s):  
Ching-Sheng Huang ◽  
Ya-Hsin Tsai ◽  
Hund-Der Yeh ◽  
Tao Yang

Abstract. Oscillatory pumping test (OPT) is an alternative to constant-head and constant-rate pumping tests for determining aquifer hydraulic parameters without water extraction. There is a large number of analytical models presented for the analyses of OPT. The combined effects of wellbore storage and initial condition regarding the hydraulic head prior to OPT are commonly neglected in the existing models. This study aims to develop a new model for describing the hydraulic head fluctuation induced by OPT in an unconfined aquifer. The model contains a typical flow equation with an initial condition of static water table, inner boundary condition specified at the rim of a finite-radius well for incorporating wellbore storage effect, and linearized free surface equation describing water table movement. The analytical solution of the model is derived by the Laplace transform and finite integral transform. Sensitivity analysis is carried out for exploring head response to the change in each of hydraulic parameters. Results suggest that head fluctuation due to OPT starts from the initial condition and gradually tends to simple harmonic motion (SHM) after a certain pumping time. A criterion for estimating the time to have SHM since OPT is graphically presented. The validity of assuming an infinitesimal well radius without wellbore storage effect is investigated. The present solution agrees well to head fluctuation data observed at the Boise hydrogeophysical research site in southwestern Idaho.


Author(s):  
R. S. Shtengelov ◽  
E. A. Filimonova ◽  
I. S. Shubin

Interpretation problems of long-term anisochronous multi-well pumping test under oscillating atmosphere pressure is analyzed. The barometric efficiency and corrections of measured drawdowns are calculated to Udomlya groundwater basin, evaluation of space and temporal moving of depression cone is investigated. Obtained hydraulic parameters is used for numerical model of groundwater basin and forecasting of periodical compensation wells pumping for recharge lake-coolers of Kalininskaya Nuclear Power Plant.


Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 744
Author(s):  
Daniel Kahuda ◽  
Pavel Pech

This study analyzes the unsteady groundwater flow to a real well (with wellbore storage and the skin effect) that fully penetrates the confined aquifer. The well is located within an infinite system, so the effect of boundaries is not considered. The Laplace-domain solution for a partial differential equation is used to describe the unsteady radial flow to a well. The real space solution is obtained by means of the numerical inversion of the Laplace transform using the Stehfest algorithm 368. When wellbore storage and the skin effect dominate pumping test data and testing is conducted for long enough, two semilogarithmic straight lines are normally obtained. The first straight line can be identified readily as the line of the maximum slope. The correlation of the dimensionless drawdown for the intersection time of this first straight line, with the log time axis as a function of the dimensionless wellbore storage and the skin factor, is shown. This paper presents a new method for evaluating the skin factor from the early portion of a pumping test. This method can be used to evaluate the skin factor when the well-known Cooper–Jacob semilogarithmic method cannot be used due to the second straight line not being achieved in the semilogarithmic graph drawdown vs. the log time. A field example is presented to evaluate the well rehabilitation in Veselí nad Lužnicí by means of the new correlation.


1984 ◽  
Vol 56 (3) ◽  
pp. 765-771 ◽  
Author(s):  
M. R. Pinsky

The relationship between right atrial pressure (Pra) and venous return describes a venous return curve. Because changes in venous return and right ventricular stroke volume (SVRV) are similar during small tidal volume (VT) breathing, we compared the relationship of SVRV and Pra during positive-pressure ventilation (VT less than 10 ml/kg) in 17 pentobarbital-anesthetized, closed-chest, canine preparations. The SVRV-Pra relationship describes a straight line with a negative slope and a positive mean systemic pressure (Pms)-zero flow intercept (instantaneous Pms). Instantaneous Pms is similar to ventricular fibrillation-induced (stop-flow) Pms (8.1 +/- 0.8 vs. 8.4 +/- 0.7 mmHg, mean +/- SE). With volume infusion, both instantaneous and stop-flow Pms increase to a similar degree (R = 0.9014, P less than 0.001). The effect of opening an arteriovenous fistula is time dependent and variable between dogs, but by 30 s it is associated with an increase in instantaneous Pms (5.2 +/- 3.2 mmHg). Vascular compliance determined by adding and removing blood from the intravascular space displays a curvilinear hysteresis. The instantaneous venous return curve is affected by intravascular blood volume, vasomotor tone, and resistance to venous return. The relationship between SVRV and Pra during small VT breathing define instantaneous venous return curves similar to those described using right-heart bypass preparations.


1979 ◽  
Vol 4 (2) ◽  
pp. 125-133
Author(s):  
Ramesh Gupta

The sharp rise in prices in recent years has stirred up a brisk debate on the meaning and measurement of business income. In computing income, costs of labour and material are generally reflected in current prices, but the provision made for depreciation is generally not sufficient to replace fixed assets. This paper investigates various approaches to the oroblem of providing sufficient depreciation allowance in measuring income. The relationship between written down value and the straight line inflation adjusted method of providing depreciation has been examined. Simulation technique has been used to illustrate the problem and pertinent policy implications of the use of various depreciation methods have been highlighted.


2006 ◽  
Vol 1 (3) ◽  
pp. 270-283 ◽  
Author(s):  
Charilaos Papadopoulos ◽  
J. Andrew Doyle ◽  
Brian D. LaBudde

Purpose:The purpose of this study was to determine the relationship between various lactate-threshold (LT) definitions and the average running velocity during a 10-km and a 21.1-km time trial (TT).Methods:Thirteen well-trained runners completed an incremental maximal exercise test, a 10-km TT, and a 21.1-km TT on a motorized treadmill. Blood samples were collected through a venous catheter placed in an antecubital vein. Pearson's correlation coefficients were used to determine the relationship between the running velocity at the different LT definitions and the average running velocity during each TT. A dependent t test was used to determine statistical differences for the mean lactate response between the 2 running distances.Results:The LTDmax, the point on the regression curve that yielded the maximal perpendicular distance to the straight line formed by the 2 endpoints, was the LT definition with the highest correlation for both 10-km (r = .844) and 21.1-km TTs (r = .783). The velocity at the LTDmax was not, however, the velocity closest to the performance velocity for either distance. The mean running velocity at each LT was significantly different and tended to overestimate the mean TT performance velocities. The mean lactate concentration during the 10-km TT (3.52 ± 1.58 mmol) was significantly higher than during the 21.1-km TT (1.86 ± 0.90 mmol).Conclusion:These results indicate that a single LT point cannot be reliably associated with different running distances. Furthermore, these data suggest that a different methodology for estimating the LT that considers individual responses might be required for different running distances.


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