REGIONALIZATION OF FLOODS IN NEW-BRUNSWICK (CANADA)

This study uses the method of peaks over threshold (P.O.T.) to estimat e the flood flow quantiles for a number of hydrometric stations in the province of New Brunswick, Canada. The peak values exceeding the base level (threshold), or 'exceedances', are fitted by a generalized Pare to distribution. It is known that under the assumption of Poisson proc ess arrival for flood exceedances, the P.O.T. model leads to a general ized extreme value distribution (GEV) for yearly maximum discharge val ues. The P.O.T. model can then be applied to calculate the quantiles X -T corresponding to different return periods T, in years. A regionaliz ation of floods in New Brunswick, which consists of dividing the provi nce into 'homogeneous regions', is performed using the method of the ' region of influence'. The 100-year flood is subsequently estimated usi ng a regionally estimated value of the shape parameter of the generali zed Pareto distribution and a regression of the 100-year flood on the drainage area. The jackknife sampling method is then used to contrast the regional results with the values estimated at site. The variabilit y of these results is presented in box-plot form.