Hi, I'm using GSSHA for the first time and facing many problem while modeling the channel flow. The simulation has following properties: - grid: cellsize 5 m - 1 channel with 10 links - very short precipitation with nearly zero intensity (simulation without percipitation is only possible in a longterm simulation, isn't it?) - rating curve as downstream boundary condition - const. discharge as upstream boundary condition (set as a stream boundary condition, typ variable flow) - simulation time 500 min, timestep 10s - no overbankflow I expected to see constant discharge and channel depth for the time of the simulation, but the hydrograph shows instability. Did I use wrong boundary conditions? What can I do to increase stability? Thanks!