TTGA (Topological Tools for Geomorphological Analysis) is a tool which helps the analysis of river systems, in particular, braided rivers and estuaries. The focus of the tool is the computation of river networks from a digital elevation model (DEM) of the river bed. Such a river network can then be used as input for further analyses, such as computing the length or average elevation of channels.

TTGA is open-source and can be found on GitHub.