Complex hydrological events such as ~oods always appear to be multivariate events that are characterized by a few correlated variables[ A complete understanding of these events needs to investigate joint probabilistic behaviours of these correlated variables[ The lognormal distribution is one of frequently selected candidates for ~ood!frequency analysis[ The multivariate lognormal distribution will serve as an important tool for analysing a multivariate ~ood episode[ This article presents a procedure for using the bivariate lognormal distribution to describe the joint distributions of correlated ~ood peaks and volumes\ and correlated ~ood volumes and durations[ Joint distributions\ conditional distributions\ and the associated return periods of these random variables can be readily derived from their marginal distributions[ The approach is veri_ed using observed stream~ow data from the Nord river basin\ located in the Province of Quebec\ Canada[ The theoretical distributions show a good _t to observed ones [ Copyright ร 1999 John Wiley + Sons\ Ltd[ KEY WORDS ~ood peak^~ood volume^~ood duration^lognormal distribution^bivariate lognormal dis! tribution^marginal distribution^conditional distribution Correspondence to] Dr Sheng Yue\ Atmospheric Environment Branch\ Environment Canada\ Ontario Region\ 64 Farquhar Street\ Guelph N0H 2N3\ Canada[ E!mail] sheng[yueรec[gc[ca