Regional Frequency Analysis of Low Flow Using L-moments for Labrador, Canada

摘要

This paper presents the results of a regional low flow frequency analysis for Labrador, Province of Newfoundland and Labrador. This study is the first regional low flow frequency analysis conducted in this region. The regional frequency analysis was based on the L-moments approach applied to annual minimum flows from 12 stream flow gauging sites with more than 15 years of data. The discordancy indices and homogeneity test show that all 12 stations can be considered as belonging to a homogeneous region. The three-parameter lognormal distribution was identified as the most appropriate regional distribution for the region. The index flow procedure was then used to obtain regional low flow estimates for any return period. In addition, a good fitting regression equation was obtained between the mean annual low flows and the basin areas. The regional approach was finally validated using data from rivers not used in the model development. The results showed that the regional low flow frequency estimation procedure was easy to implement and provided good results.