MODULE: IHACRES Calibration(2)

Author: | Stefan Liersch
Contact: | stefan.liersch@ufz.de; stefan.liersch@googlemail.com
Last modification: | 2008
Menu: | Hydrology >IHACRES<

DESCRIPTION

Monte-Carlo Calibration Tool for the metric conceptual IHACRES Model

REFERENCES
Jakeman, A.J. / Hornberger, G.M. (1993).
How Much Complexity Is Warranted in a Rainfall-Runoff Model?
Water Resources Research, (29), NO. 8 (2637-2649)
Croke, B. F. W., W. S. Merritt, et al. (2004).
A dynamic model for predicting hydrologic response to land cover changes in gauged and ungauged catchments.
Journal Of Hydrology, 291(1-2): 115-131.

MODEL STRUCTURE

PARAMETERS

Description of common module parameters

Parameter | Description
INPUT TABLE |
>> Table | Select the input table from the SAGA workspace (3.1). Load the input table to the SAGA workspace before you start the module!
Date column | Select the column storing the date. Format: yyyy-mm-dd
Streamflow column | Select the column storing daily observed streamflow data in [m3/s].
Precipitation column | Select the column storing daily precipitation data in [mm].
Temperature column | Select the column storing daily mean air temperature in [°C].
Using temperature data? | If the checkbox is activated: temperature data are used in the simulations. If the box is not checked: temperature data are not used in the simulations. This function is currently not implemented, so please always tick the box!
Area of the watershed | The total area of the watershed / catchment in [km2].

Storage

Three options are available

- Single Storage (in humid climates the configuration with two parallel storages should be favoured, where a single storage configuration might be reasonable in some arid climates)

- Two Parallel Storages (see Figure)

- Two Storages in Series: This version is not yet implemented!

IHACRES version

- Jakeman and Hornberger (1993). This version is the original version of the IHACRES model based on a three parameter non-linear module. The version is implemented in all modules and should be used. Other versions are in the experimental phase.

- Croke et al. (2005). This version uses a five parameter non-linear module. Hence two more parameters are required in the calibration process.

Snow module on/off | If the checkbox is activated, the snow module is used during calibration or simulation.
TIME RANGE |
First day | The first day of the calibration or simulation period. Use the format as determined by the dialog. Normally, it is in the form: yyyy-mm-dd
Last day | The last day of the calibration or simulation period. Use the format as determined by the dialog. Normally, it is in the form: yyyy-mm-dd

NON-LINEAR MODULE | See Jakeman and Hornberger (1993); Croke et al. (2005) for a more detailed description of the non-linear loss module and its parameters.
Tw | Reference drying rate. The rate at which the catchment dries out.
f | Temperature modulation factor which determines how Tw changes with temperature. If the original IHACRES version is used (Jakeman and Hornberger, 1993) the valid parameter range is between 0.05 and 0.5. For the Croke et al. (2005) version the range is between 0.0 and 5.0.
c | Volumetric storage coefficient of the catchment. A normalizing parameter. It is chosen so that the volume of effective rainfall is equal to the total streamflow volume over the calibration period. It is the increase in storage index per unit rainfall in the absence of evapotranspiration.
l | Soil moisture index threshold. (Only in the Croke-Version)
p | Non-linear response term. (Only in the Croke-Version)
LINEAR MODULE | See Jakeman and Hornberger (1993); Croke et al. (2005) for a more detailed description of the linear routing module and its parameters.
aq, as | Quick and slow flow recession rates. If the option Single Storage is selected only one "a" parameter is required.

bq, bs

Fractions of effective rainfall for peak response.

- For storage configuration Single Storage only one "b" parameter is required.

- For storage configuration Two Parallel Storages only parameter bq is required and bs is calculated depending on the values selected for aq, as and bq (see Jakeman and Hornberger (1993) for a detailed description).

Time delay (rain-runoff) | A time step delay that accounts for the delay between rainfall and streamflow response. In small to meso-scale catchments this value is often 0 or 1. The default setting is 1 day (time step).
SNOW MODULE | See EoW (2008); Seidel and Martinec (2004) for a description of the simulation of snow melt processes based on the degree-day method.
Temperature threshold for rainfall (T_Rain) | Below this temperature [°C] precipitation will fall as snow and not as rainfall.
Temperature threshold for melting (T_Melt) | Above this temperature [°C] an existing snow cover starts melting.
Degree-day factor (DD-FAC) | The degree-day factor [mm * °C-1 * d-1] determines the density of the snow cover. A wide range of degree-day factors (0.7 to 9.2) has been reported in literature.