slope bottlenecks

[jtgilbert]

If there is a sudden drop in slope between two segments it creates a huge storage bottleneck.

[jtgilbert]

trying this fix:

for i in network.index:
    ds = topo.get_next_reach(i)
    if ds is None:
        ds = topo.get_next_chain(i)
        
    if ds is not None:
        if network.loc[ds, 'Slope'] <= 0.5 * network.loc[i, 'Slope']:
            network.loc[ds, 'Slope'] = 0.5 * network.loc[i, 'Slope']

[jtgilbert]

fix helps but hasn't been pushed yet.