Regional flood frequency estimation and network design

The use of probability weighted moments has been investigated for improving estimates of flood recurrence quantile events in both gauged and ungauged basins. Regional estimates at gauged sites are improved over more conventional methods such as method of moments and maximum likelihood estimation. An improved method for ungauged basins is proposed which incorporates both probability weighted moment techniques with more traditional mean peak flow estimation. The question of network design in terms of number of sites and number of years of record is reexamined in light of the probability weighted moment techniques.