The problem studied in the framework of this work is devoted to issues related to the projected excavation of soil from the channel part of the Sidorovskoye sand and gravel deposit on the river. Kama. The channel part of the deposit is located at 1639.0-1644.5 km of the Nizhnekamsk sluice–mouth of the river. Vyatka, which is the upper part of the Kuibyshev reservoir. The paper presents the results of the analysis of channel reformations of the studied section of the river according to field data and hydraulic calculations performed to model the channel process in the section of the river. Kama, is located in the downstream of the N. Kamskaya HPP, taking into account the planned engineering measures related to the extraction of river alluvium from the channel open pit.

The problem investigated in the framework of this work is devoted to the study of changes in the hydrological and channel regimes of the estuary region after the construction of the Southern Port area. The object of the study is the Khabolovka River, which flows into the Luga Bay. Based on the materials of channel surveys, the article gives a modern assessment of the general condition of the channel, presents data on manmade changes in the hydromorphological structure. After the conducted research, it was determined which consequences affecting the hydromorphological appearance of the considered section of the river have now occurred from the influence of various factors. Taking into account the performed and studied in detail analysis of riverbed transformations on the river section, it is possible to formulate the main conclusions and recommendations. As a result, a forecast of the further course and changes of the estuary area of the river is given if the necessary measures to protect against wind-wave influence are not carried out.

The hydromorphological situation at the site of bridge construction is analyzed in the paper; the analysis results are presented. The issues of ensuring the channel geometry stability are considered. The impact of a temporary construction embankment on the f low kinematics is estimated. The level regime of the river and the channel reformations in the alignment of the bridge crossing and on the upstream section of the river are studied at the calculated level and water flow. The results obtained make it possible to determine and establish the values of the permissible degree of impact of the designed hydraulic structures and measures on the channel regime of the near-mouth section of the Zeya River in the area of the projected bridge crossing over the river in Blagoveshchensk, within which the natural and anthropogenic-induced conditions of the statistical stability of the “flow-moving channel” system are realized by the river flow. The studies were carried out in 2 stages: the first one, a test stage, was carried out for the initial everyday state of the riverbed in the section of the Zeya River in the area of the bridge crossing, according to which the model was calibrated in accordance with the specified boundary conditions in the area under study; the second one, on the model, was carried out for three options of the construction dam length, erected from the left bank to the 15th pillar of the bridge, to the middle of the span between the 15th and 16th pillars and up to the 16th pillar of the bridge crossing, which made it possible to assess the impact of the structure with different options of its length on the flow hydraulics in the area of the bridge crossing. The research method applied is the mathematical 2-D modeling of the water movement characteristics, for which the “FLOOD” software package is used.