Tessera, Abebe(PhD)Gebreyohannes, Emmanuel2018-06-252023-11-092018-06-252023-11-091994-06http://10.90.10.223:4000/handle/123456789/3248In this research, statistical work in stochastic modelling of hydrologic time series is discussed. The theme is the comparison of stationarity and non-stationarity approaches for stochastic simulation of monthly streamflow sequences. The paper first introduces various concepts related to stochastic modelling; the history of stochastic simulation and applications of stochastic modelling in hydrology; and the step-by-step modelling procedures. Then the paper describes how synthetic streamflow sequences can be generated using these procedures. As a particular case, synthetic streamflow sequences were generated for two streams in Ethiopia using both stationarity and non-stationarity approaches. At last, based on these synthetic flows, an attempt was made to compare the performance of the two approaches with some comments and recommendationsenStreamelowThesis