Mp. Mccartney et Ps. Naden, A SEMIEMPIRICAL INVESTIGATION OF THE INFLUENCE OF FLOODPLAIN STORAGE ON FLOOD FLOW, Journal of the Institution of Water and Environmental Management, 9(3), 1995, pp. 236-246
A simple model is used to assess the effect of floodplain storage on f
lood flows, with a view to developing methods for general use in flood
-frequency estimation. Recent floods on the River Severn at Montford a
re 'unrouted' in order to determine the shape and magnitude of the hyd
rographs, provided that there had been no overtopping and all flows ha
d been contained within the banks. The model used to unroute the hydro
graphs has, at its core, a relationship between water depth and floode
d area derived from a coarse (50 m) digital terrain model developed fr
om Ordnance Survey 1:50 000 maps. The implications for flood-frequency
curves at sites downstream from significant flood-plain storage are d
iscussed.