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Impact of river stage fluctuations

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Impact of river stage fluctuations

The dialog window "River width and hydrograph" is used for entering the width of streams and uploading hydrographs of river stage. Hydrographs with water level fluctuations can be uploaded from one of the three types of files below:

1)File dqstep.at - containing river stage fluctuations, that are discretised into time steps. This file is created in the Editor for conceptual model "Natural fluctuations";

2)File dq.at that is created in the interpretation process (menu "Tools>Step-function")

3)File *.dat that contains two columns: 1) time (higher than 0) of water level change and 2) water level change.

For the files, where fluctuations are not discretised into time steps, the program will discretise fluctuations automatically.

The dialog window is accessed through the button "River", that is located on the tab "Parameters" of the dialog window  "Matching parameters". This button is enabled if conceptual model "Pumping near river" is selected. Alternatively, most of the conceptual models with the 1-st type of hydrodynamic boundary will enable the button "River"

 

Dialog window "River width and hydrograph".

 

Interpretation is conducted using drawdown superposition principle, when river-caused drawdown is added to drawdown that resulted from pumping/injection. For the conceptual models "Natural fluctuations" and "Pumping near river" as well as the applied solution of Hantushriver bed resistance is calculated as: km'/k'. For all other solutions river bed resistance is calculated by formula:

where T = km; b – width of river.

 

After entering value in the "Width of river" field, resistance of river bed is calculated automatically and appears in "dL_H" field. The latter value is used by the program for calculations of drawdown impacts in aquifer testing.

The checkbox "Level fluctuations in the river" switches on/off depending on the selected interpretation solution accounting for river stage fluctuations. If error is found in the entered data, this check box automatically switches off.

If the selected solution doesn't include river bed resistance, the frame "Parameters for recalculation" in the dialog window "River width and hydrograph" becomes inactive.