Configuring Model Alternative Keys

To complete the configuration of a model alternative, you must assign each model alternative a Model Alternative Key. The model alternative key is an alpha-numeric identifier that must be unique within each model, but can be replicated across other various model alternatives. For example, you may choose to identify an HEC-MetVue model alternative as N for "no future rain" and an HEC-HMS model alternative as N for "normal conditions". However, you cannot assign N to two HEC-MetVue model alternatives.

Assigning Model Alternative Keys

To assign model alternative keys:

Within the Setup module, select Model Alternative Keys from the Models menu. The Model Alternative Keys dialog will open.
Using the Plugin drop-down list, select the model for which you wish to assign a key.
In the Key field, enter a single unique alpha-numeric character that will be used to identify the listed Model Alternative.
Repeat Steps 2 and 3 for all models and model alternatives.
Click OK, and the Model Alternative Keys dialog will close.

Once you assign a key to a model alternative, it cannot be changed, so choose wisely.

Model alternatives for the standard programs in CWMS might be named similar to the following:

Example Model Alternatives for HEC-MetVue
ID	Name
N	No future precipitation
2	2-inches future precipitation
4	4-inches future precipitation
Q	QPF
R	One-half QPF
S	Twice QPF

Example Model Alternatives for HEC-HMS
ID	Name
N	Normal conditions
W	Wet basin conditions
D	Dry basin conditions

Example Model Alternatives for HEC-ResSim
ID	Name
N	Normal operations
R	Restricted downstream channel capacity
W	White water release schedule
S	Fish spawning release schedule

Example Model Alternatives for HEC-RAS
ID	Name
N	Normal river conditions
H	High channel roughness
L	Low channel roughness
B	Bridge out

Example Model Alternatives for HEC-FIA
ID	Name
N	Normal conditions
E	Evacuated with warning