Problems of the hydrodynamics and Deposition in Estuaries and River Mouths

Abstract

Inclusion of the technical session D "Deposition in Estuaries and River Mouths" in the program of the 14thCongress of the IAHR was due to a number of circumstances closely related to the economic utilization of the regions of river mouths and seashores. In connection with the trend toward an increase in the size of shil~ , especially tankers, the ixoblem of cow'trolling deposition in the approach channels is becoming exceptionally urgent. Mud-botZom channels subjected to tidal currents are of particular interest.In recent years problems of the hydrodynamics of fiver mouths and shores have also acquired importance in connection with the creation of large reservoirs for power purposes on rivers emptying into the sea, since the retention of sediments in reservoirs causes intense wave erosion of the shore. To forecast the consequences of streamflow control by re.~rvoirs with respect to the stability of the seashore, it is necessary to have a clear idea of the disrribution of sediments within the estuatine shore, which requires the development of the hydrodynamics of river mouths and shores.Finally, the prediction of changes in the hydrologic regime of rivers in connection with diversion of the runoff from the basin to another for the purpo~ of maintaining a sanitary condition of the river mouths, supplying drinking and industrial water and for reclamation, fisheries, etc., also requires a more comprehensive study of the hydrodynamic regime of river mouths and estuaries.At technical session ]3, 28 reports were presented: six from the USA, four each from the USSIL France, and Great Britain; two from Holland; and one each from India, Turkey, Portugal. Japan. Brazil. Mexico, Canada. and West Germany. These reports can be divided into the following groups according to the character of the investigations: a) theoretical methods of predicting the deposition of sediments in estuaries and transformation of the shore in the region of river mouths (reports 1, 5, 10-14, and 19); full-scale investigations of deposition in river mouths (reports 4, 13, 16, 21, and 28-28); c) experimental study of sediment transpcet in rivers and estuaries on physical and mathematical models (reports 2, 3, 6-9, 11, 12, 17, 18, 20-24, and 26). The brief content of these reports, of interest to Soviet hydraulic engineers, is given below.A. Harrison and M. Owen (D.I,~" England) investigated the transport of fine sediment in estuaries as a recurring cycle of four processes: erosion, transport of suspended sediment, its deposition and consolidation. Each of these processes depends on the hydraulic regime of the flow and characteristics of the sediment and can be expressed only by empirical formulas Qith constants obtained in the laboratory and in full-scale observations. The report discussed the prediction of deposition in the ship channel on the Pleit River located perpendicular to the stream.S. C-oul, Z. Tarapor, and S. Brahme (D.S, India) presented a method of predicting deposition in harbors and channels based on an analysis of full-scale, model, and...