Nodes of different colours represent the following:
Solid arrows point from a submodule to the (sub)module which it is
descended from. Dashed arrows point from a module or program unit to
modules which it uses.
Where possible, edges connecting nodes are
given different colours to make them easier to distinguish in
large graphs.
read snow database data from snow.sno
read saturated buffer inputs for all src/rcv hrus
set initial parameters
set saturated buffer parameters for source and receiving (buffer) hrus
crosswalk to get number of flow control decision table