Drought definition criteria and their influence on the drought characteristics.2. One-dimensional probability distributions

For adopted 12 drought definitions and basing on 49-year time series of daily flows at four cross-sections in the Mała Wisła catchment, it was found that the probability distributions of drought duration T and drought deficit V may be described by the lognormal distribution with parameters estimated by the maximum likelihood method. The goodness-of-fit quality was tested by the Anderson-Darling and Cramér-von Mises tests. Both test did not reject the tested distribution neither for any definition nor any cross-section, as the p-values were greater than 15% for the former test and greater than 20% for the latter. ...

Drought definition criteria and their influence on the drought characteristics. 3. Joint probabilisty distribution of drought duration and deficit

For adopted 12 drought definitions and basing on 49-year time series of daily flows at four cross-sections in the Mała Wisła catchment, it was found that the probability distributions of drought duration T and drought deficit V may be described by the two-dimensional lognormal distribution with parameters estimated by the maximum likelihood method. The goodness-of-fit quality was tested by the Anderson-Darling and Cramér-von Mises tests. Both test did not reject the tested distributions neither for any definition nor any cross-section: all of the p-values were greater than 20%. ...