Conceptual Groundwater:Conceptual Groundwater

Conceptual groundwater scheme is a scheme that takes account of recharge of infiltrated water from the GSSHA infiltration scheme to the conceptualized groundwater vertical profile. The scheme consists of fast and slow component to add flavor of free and tensile water (Burnash, 1995). A variable named ‘congw_input’ in the function ‘mainloop_infiltrate’ collects infiltrated water as a recharge to conceptual ground water.

Cards and files used in the project file

card file

CONCEPTUAL_GW *.con

LINKS *.lik

CONCEPTUAL_GW card is required to run the conceptual groundwater in GSSHA. This card is associated by the file *.con. This file contains the parameters and varaibles used in the conceptual groundwater.

Conceptual groundwater parameters and example parametric values in *.con file.

GSSHA_CONCEPTUAL_GW

SLOW_MAX 100.0

FAST_MAX 500.0

SLOW_RATE 0.003181

FAST_RATE 0.0312

SLOW_CONTENT 0.36600

FAST_CONTENT 0.2113

UNDERFLOW_PERCENT 0.00

SLOW_MAX is the maximum storage in slow aquifer in mm.

FAST_MAX maximum storage in fast aquifer in mm.

SLOW_RATE rate constant between 0-1, determined by calibration.

FAST_RATE rate constant between 0-1, determined by calibration.

SLOW_CONTENT slow_content/slow_max - initial condition, must be 0-1.

FAST_CONTENT fast_content/fast_max - initial condition, must be 0-1.

UNDERFLOW_PERCENT is the percent of base flow that does not contribute to stream.

Lateral base-flow contribution to channel segment

*.lnk file is the location of the channel running grids. In developing conceptual groundwater, it is necessary to define the portion of the base flow that enters a channel segment. Groundwater contributing area to stream segments is defined by the contributing area of the stream segment.

References

Burnash R.J.C., 1995, The NWS river forecast system - catchment modeling, Computer models of watershed hydrology, Edited by V. P. Singh, pp. 311-366.

GSSHA User's Manual

21 Conceptual Groundwater