To substantiate measures aimed at prevention of siltation of supply and transport channels in the Danube lakes (study of hydraulic and alluvial regimes)

Abstract

Underwater bucket channels connecting the Danube with sluices were built perpendicular to river’s main stream. Water supply tract consists of an supply bucket channel, connecting the Danube with a sluice facility, a transporting channel – from a sluice to the mouth, i.e. to an output of a channel into a lake, and a mouth section of a channel. Throughout the whole period of operation of these facilities silt accumulation has been observed within supply bucket channels, in a lesser degree – within transport channels, and emergence in a mouth section of transport channels of sandbars having considerable dimensions. Throughout the whole period of operation of facilities and channels plenty of money has been spent for cleaning facilities and channels off sediments, so there is a need for deeper examination of the nature of silting phenomenon and minimization of water supply tract siltation through its simple reconstruction.

The aim of this research consists in substantiation of proposals to eliminate or to reduce effects of silting of supply and transport channels under existing conditions and substantiation of proposed necessary structural measures on the basis of proposed mathematical modelling and methods of analytical studies. Therefore methods of analytical studies including probable and statistical approaches used when analyzing processes with constant change of environment were proposed. These studies found that boundaries of supply of inlet channels in an open river’s channel depend on distribution of flow velocities throughout a river’s stream and conditions of stream distribution and flow pattern in the middle of the supply channel depends on shape of an inlet, particularly on shape of its lower side.

These suggestions and studies give us an opportunity to recommend means of controlling a hydraulic regime in the middle of a supply channel. Fighting against deposition of bottom sediments at supply channels may be won after choosing a place for water intake and a type of bucket, as well as after specification of appropriate structural forms and sizes of their inlet components. Therefore the article provides suggestions on research of regime of interaction between the river and a supply channel, dynamics of water exchange in supply channels, forces of stream masses developing during mixing, hydraulic regime and regime of deposition of supply and transport channels in order to determine the major requirements regarding size of water area of a supply channel.