Building Trees

A topologic tree can be used to create a watershed configuration in the absence of digital terrain or feature object data (the only possibility for the public domain version of WMS). The tree representation can then be used to select basins and outlet points for entry of all basin and routing data, in the same way the digital terrain based watershed map can be used. Geometric parameters such as areas, lengths, and slopes, which can be automatically computed when a digital terrain model is used, must be entered interactively. However, all other features of the hydrologic modeling interfaces work in the same fashion.

All of the functions for building and/or editing trees (except diversions and reservoirs) cannot be used when a digital terrain model is used. In this case, all new basins and outlet points must be created from the digital terrain model.