Calibration of the RRM-Model
Introduction
The RRM Model is a dynamic basin scale
water budget model that operates at a daily or hourly timestep.
It is designed for ungauged sub-catchments, estimating their outflow
as a function of basin characteristics, rainfall and temperature.
Its primary purpose is to provide input to the WRM water resources model.
The basic model processes represent a series of cascading reservoirs.
The automatic calibration tool uses an unconventional approach:
rather than formulating an objective function such as a squared error term,
we use a concept of regions in behaviour space that the
model trajectory must pass to generate an acceptable run.
These regions are, initially, defined in terms of
- A time interval (anything from a single day to the entire year);
- A CONCEPT (like minimum, maximum, average, or VALUES) computed from
the model results;
- A range, derived from the observations or expert knowledge
within which that concept has to fit for that interval.
You may want to picture this as an obstacle course in model behaviour space,
the routine trying to find (and map) regions in parameter space
that lead to model runs getting through the obstacle course with all conditions met !
Criteria or Constraints
Each Criterium is specified in one line of the criteria Definition form.
- From Field:
specifies the starting date of the period in which the criterium is checked
- To Field:
specifies the end date of the period in which the criterium is checked
- Min Field:
specifies the start of the range in which the evaluation of Function must be to meet the criterium
- Max Field:
specifies the end of the range in which the evaluation of Function must be to meet the criterium
- Function Field:
specifies the Function which is evaluated to be between min and max.
Available functions are:
- MIN ... Minimum of values in period must be between min and max
- MAX ... Maximum of values in period must be between min and max
- SUM ... Sum of values in period must be between min and max
- AVG ... Average of values in period must be between min and max
- VALUES ... all values in period must be between min and max
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