Tim McConnell 0 Report post Posted December 20, 2010 I am running a steady-state model of a network of creeks joining a main branch. My problem is by running the steady-state model the cumulative effect of adding flows means my model has too much flow in the downstream reaches. Is it viable to remove water from downstream reaches using a SA polygon? Is the SA boundary taking out the same amount of flow with different number of wet cells within the polygon? Any advice would be great. Cheers. Quote Share this post Link to post Share on other sites
peteraylett 0 Report post Posted December 20, 2010 Hi, Unfortunately, the effect you're describing is very much a result of doing the run in steady state. In a real event, where there are limited duration inflows into a river system, there is both the effect of storage/attenuation within the system and the different timings for the peaks to travel down the system. The two features both contribute toward the expectation that the peak flow downstream should be (will be) lower than the sum of the peak flows upstream. The use of steady state is therefore not recommended for this type of situation. Also, I would be extremely cautious of just subtracting the extra flow with an SA, as you won't know where throughout the river network those flows should be reduced... In short, I would say this problem is best solved by heading unsteady! Though I appreciate generating hydrographs is not necessarily a trivial task. PHA. Quote Share this post Link to post Share on other sites