Format of Catchment Files

Catchment files are similar in format to overlay files. They contain a series of points connected by vectors. They also support a ";" for comments, and END to mark the end of the file. There is only one file header command.

IRIS supports a maximum of 20 catchment files.

Catchment File Commands

Command	Description
DRAW_CENTER lon lat	Tells overlay where to center the image. Generally this is the either the coordinates of the radar site, or the center of the catchment area.
SIZE size	Sets the size to draw subcatchment names. This is the height in pixels, and it applies until the next size command in the file.
WARNING threshold	Specifies warning threshold in mm. An alert is issued if this is exceeded, and it applies until the next warning command in the file. A value of 0 means no alerts.

Catchment files are divided into a series of subcatchments. Each starts with a header specifying the name and label location followed by the data points. The datapoints must define a closed polygon. Make sure the last point matches the first one. There can be a maximum of 512 subcatchments defined in each catchment file.

Subcatchments

Subcatchment	Description
START number name	Tells the number and name of the subcatchment area.
LABEL lon lat	Specifies the location to draw the name when labeling the subcatchment. This location must be inside the region.