Analysis of Hydrological and Fluviomorphological Regimes of the Ob River Delta

Data on water discharges and levels, morphometry of river branches, elevation base, runoff, and granulometric composition of sediments in the Ob Delta over the period of instrumental measurements were analyzed and summarized. The obtained results served as a basis for the delta parameterization. Detailed characteristics of the hydrological regime and quantitative characteristics of reversible fluviomorphological deformations averaged for the deltaic water streams were defined at different water levels in the channel. A many-year trend of these deformations was revealed. It was found that in the period between two cycles of field studies of the Ob Delta, no noticeable changes occured in the distribution of water discharges by the main branches at the delta head. Some secondary water streams in the delta lower reaches, where field observations were carried out over the mentioned period of time, featured a certain decrease in the flow discharged by these water streams along with a simultaneous increase in the water turbidity. The area of possible application of the obtained results was outlined.