Dialog window "Transmissivity, storativity" is used for quick estimates of transmissivity and hydraulic diffusivity of aquifer based on reaction time of water levels in an observation well to water levels recovery in a pumping well. The tool also includes averaging options for heterogeneous aquifers and layered systems.
The window is opened by "File > Hydrogeologist workbench > Estimation of parameters > Transmissivity, storativity".
"Transmissivity" tab of "Estimation of parameters" dialog box.
Explanatory table for tab "Transmissivity"
Estimates of transmissivity in confined and unconfined aquifers based on specific discharge during aquifer tests.
"Q, m3/day" text box |
Constant discharge rate of a pumping well, m3/day |
"s, m" text box |
Drawdown at the end of pumping test, m |
"m, m" text box |
Initial saturated thickness of aquifer, m |
"Confined aquifer", "Unconfined aquifer" option |
Selection between confined and unconfined aquifer types |
"T, m2/day" text box |
Information field to display the calculated transmissivity, m2/day
|
"k, m/day" text box |
Information field to display the calculated hydraulic conductivity for unconfined aquifer, m/day
When mouse cursor is placed over this field, the context info shows the transmissivity value for the specified initial saturated thickness |
"Hydraulic diffusivity" tab of "Estimation of parameters" dialog box.
Explanatory table for tab "Hydraulic diffusivity"
Calculates hydraulic diffusivity based on time of reaction of water levels in observation well on recovery in pumping well
"to, day" text box |
Duration of pumping, days |
"ts, min" text box |
Time (since cease of pumping), when water level starts to recover in observation well, minutes |
"r, m" text box |
Distance between pumping and observation wells, m |
"a, m^2/day" text box |
Information field to display the calculated hydraulic diffusivity
Time ts has to be converted in days before entering it in the formula above |
"Average value" tab of "Estimation of parameters" dialog box.
Explanatory table for tab "Average value"
Estimates effective values for heterogeneous and layered aquifer systems
Table |
Requires inputs of hydraulic properties and thicknesses for every layer (or every heterogeneity zone) |
List |
Selection of hydraulic property parameter (dropdown list). 1. Hydraulic conductivity (kr) of stratified aquifer system:
ki, mi – hydraulic conductivity (m/day) and thickness i-th layer; n – quantity of layers. Total transmyssivity of the aquifer system is determined as:
2. Hydraulic conductivity (kz) of stratified aquifer system:
This parameter is determined in assumption of groundwater flow that is perpendicular to the layer surfaces. 3. Transmissivity of heterogeneous aquifer:
Ti, Fi – transmissivity (m2/day) and area (m2) of the i-th heterogeneity zone; n – quantity of zones. Area can be input in any metric system (i.e. m2, km2). 4. Storage coefficient of stratified aquifer system:
Ssi – specific storage (1/m/) of the i-th layer |
"Number of layers" or "Number of heterogeneity zones" text box |
This field defines the number of rows in the table: quantity of layers or quantity of heterogeneity zones. Maximum quantity is 99. |
"Copy" button |
Copies table values in clipboard |
"Paste" button |
Pasts values from clipboard and automatically increases number of table rows, if more zones/layers are required |
"kr", "kz", "T" or "S" text box |
Information field to display the values for the estimated parameters (see dropdown list of parameters) |
"Thickness" or "Area" text box |
Information field to display the total thickness of the layered system. For heterogeneous aquifers this field displays the total area. |
"Transmissivity of aquifer system" text box |
Information field to display the total transmissivity of the layered system, m2/day. This field is only displayed for hydraulic conductivity (kr) of stratified aquifer systems |
