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From 1960 to 1969 a detailed survey of current pattern was carried out at Rosetta and Damietta estuaries of the Nile Delta and the outlets of the coastal lakes. In 1968 littoral drift observations were made using fluorescent tracers at Ra’s al-Barr. A coastal survey program in progress since 1971 at fixed locations along the coast has evaluated the dynamics of coastal erosion. The average littoral current is 35 cm se? at Burullus inlet, 40 at Rosetta exit, and 28 at Damietta. The coastal surveys have shown coastal processes, including erosion and deposition, to be different in different stretches along the deltaic coast from Rosetta to Port Said, indicating that more detailed studies over many years will be necessary. During the last century the Nile Delta coast has changed due to erosion in some places and sedimentation in others. A few centuries ago during the historical development of the delta, the two main branches, Damietta and Rosetta, were continuously protruding seaward. However, at the beginning of this century, they began to retreat. The western promontories of both the Rosetta and Damietta estuaries have retreated about 2.2 km between 1898 and 1970 (Mobarek et al. 1966; Hilaly 1971a). Recent studies indicate that the Nile flow and the sediment load discharged into the sea have both been reduced in the 20th Century from those of the 19th. With less sediment load at the promontories of Rosetta and Damietta, there has been erosion along the coast. The engineering structures on the Nile have not obstructed the flow of sediment to the sea, although by coincidence they were built since 1903. The cause of erosion was mainly climatic up to 1964, when Nasser Lake behind the High Aswan Dam began storing water; the dam completely stopped all flow and is still filling the lake. The cause of erosion along the coast since 1964 is mainly the loss of sediment supply from the Nile. Problems of coastal erosion in the Nile Delta have been reviewed by foreign and Egyptian experts. Field studies have been carried alit at different localities along the Egyptiau coast by the Suez Canal Authority. Coastal investigations near the Rosetta estuary were made from July 1969 to June 1970 (Hilaly 1971a). Field observations, including current and wave measurements, bottom sediment transport, and hydrographic conditions, were made from 1960 to 1970 at Damietta and Ra’s al-Barr areas ( Mobarek et al. 1966; Kadib 1969, 1971). The east and west shore of the Lake Burullus inlet was investigated from September 1969 to July 1970 ( Hilaly 1971b). From 1965 to 1970 sand drift observations using fluorescent sands were made along the coast (Mobarek et al. 1966; Kadib 1969; Zenkovitch 1970). Between Ra’s al-Barr and Damietta, three experirnents were carried out successively on 24 May, 2 July, and 3 August 1965, and another in the same area in 1968. In March 1970, another experiment was carried out 'by Russian scientists. Unfortmlately these studies were not made simultaneously over the entire coast of the Nile Delta, making it difficult to predict the general pattern of sand transport and its relationship with hydrographic an d meteorological conditions. The need of simultaneous data is now apparent. Recently, UNDP and UNESCO appointed an international advisory panel to oversee a shoreline protection project for the Nile Delta coast ( Nielsen 1971). Before 1964, the problem of sedimentation in the Damietta and Rosetta estuaries was naturally solved by river flow, especially LIMNOLOGY AND OCEANOGRAPIIY 182 MARCH 1974, v. 19( 2) Sand transport in the urf zone 183 1964 --1949 -*tS35 -.-19 1 1 MEDITERRANEAN SEA Fig. 1. Change of shoreline at Rosetta and Damietta during the last 60 years. during flood. Figure 1 shows the change of shoreline at Rosetta and Damietta during the last 60 years according to the Suez Canal survey ( Kadib 1969). From the surveys taken by the ships Tartarus in 1857 and Endeavour from 1919 to 1922, variations of the continental shelf in front of the Nile Delta were determined (Fig. 2). However at present erosion occurs mainly at the Rosetta and Damietta mouths, as well as along the coast between them. Figure 3 shows the regions of erosion and dcposition based on the latest Suez Canal Authority report (Kadib 1969). Sedimentation mainly takes place on the east side of the Burullus inlet, Lake Idku inlet, and along Damictta estuary. The principal problem along the Egyptian coast is longshore sand transport resulting from waves breaking at an angle to the shoreline. The effective parameter in producing these waves is the prevailing wind, which is NW or WNW. The lack of information on the longshore sand transport and wave and current patterns along the Egyptian coast makes it difficult to predict the relation between them. This paper summarizes the field investigations that have been carried out to evaluate the forces causing erosion. Sand drift experiments using fluorescent dye sand might make accurate assessment of sand transport rates possible. Oceanographic and geological surveys Hydrographic investigations During the last 30 years, cruises have been carried out along the Mediterranean coast of Egypt by research vessels from different nations. Their main purpose was to make hydrographic and biological measurements. In 1948 six hydrographic stations were taken by Atlantis and during 1955-1956 two by Calypso between the Egyptian coast and Cyprus and Crete respectivcly. In March 1959, 19 stations were taken seaward of the Nile Delta by the Japanese ship Shoyo Maru and in summer

Representing a stream channel of finite width as a surface z = z(x, y, t) subject to the three conditions: (1) that sediment mass is conserved during transport; (2) that the channel has a form just sufficient to transport its total water discharge; (3) that the channel has a form just sufficient to transport its total sediment load; and then applying the Manning equation and a well-known empirical law of sediment transport, it is possible to derive a downstream hydraulic geometry for steady-state channels. In the present case, the following geometry is derived: channel width $\propto Q^{0.6}$; channel depth $\propto Q^{0.3}$; stream velocity $\propto Q^{0.1}$; water slope $\propto Q^{-0.2}$; where Q is the total stream discharge. The model has considerable flexibility and, in modified form, should prove of use in future channel studies.

This report describes work in an IHD Representative Basin in the Quebec Appalachians, the Eaton River Basin (86 km2 in area), upstream from Randboro. The Basin is dominantly forest-covered, contains no large settlement, and, in general, shows little human disturbance that might affect sediment production. The suspended load of the Eaton River was studied in detail during the spring runoff periods of 1970 and 1971; available long-term discharge data indicate these to be representative of present-day conditions. Sediment transport rates are well below capacity and sediment yields are lower than might have been expected from the Langbein-Schumm data in the United States. Suspended sediment originates primarily from scour of the banks of the channel network, and concentrations show a systematic increase with basin area (or distance downstream), quite unlike previous data from the midwestern United States. The sediment rating curve approach is a very good predictor of sediment transport rates, although because of the differences in hydrograph type, there is a large difference between the equations for the 1970 and 1971 spring floods. This difference, and residuals from the sediment rating curves, are considered in a simulation model of sediment production from bank erosion based on the changing shear resistance of bank sediment during a fluctuating hydrograph.

Bar formation and sediment distribution patterns were examined in a 4-mile braided reach of the upper Kicking Horse River at Field, British Columbia, which is mainly supplied by meltwater from icefields straddling the continental divide at the British Columbia-Alberta boundary in the southeastern Canadian Cordillera. Marked diurnal variations in discharge, suspended sediment concentration, and water temperature occur during peak summer melting periods when rates of sediment transport and bar formation are greatest. Bed material is mostly limestone and dolomite gravel which undergoes rapid fining in the downstream direction. Gravel bars occurring in a wide variety of shapes and sizes comprise the dominant bed forms. Most exposed braid bars have undergone complex depositional and erosional histories and rarely show simple or consistent patterns of grain size or structures, either internal or superficial. Active bars with simple histories and predominantly depositional morphologies are termed "unit bars." Fo...

Experiments conducted with natural mixed populations of 800 and 1,800 tubificids m−2 in sediment from Messalonskee Lake, Maine, showed average sediment transport by alimentation at 10°C 2–3 times greater than highest rates previously reported. More than 95% of feeding on introduced pollen was at depths above 7 cm, with greatest feeding at 3–4 cm. Small amounts of pollen were raised to the surface from as deep as 15 cm. Downward transport was 14 and 19% of upward. Small pollen grains (< 40 µ) were fed upon and displaced at higher rates than large grains. Organic matter was less in the surface layer of feces than in sediment from feeding depths and in surface sediment where no worms were present. A mathematical model was used to appraise the stratigraphic effects of the worms by deriving age-frequency composition of sediment at various depths.

Channel geometry and sediment transport have been analyzed using Geographic Information System and statistical methods in Palung and Chitlang sub-watershed of Kulekhani watershed located in the Central Hills of Nepal, which covers 87.9 sq. km of land surface.The study demonstrates that the channel geometry and sediment transport changes abnormally in downstream distance for both rivers, though there are some controlling factors i.e. lithology, land use, climate, vegetation cover etc.Key words: Channel geometry; discharge; GIS; landscape; River morphologyDOI: http://dx.doi.org/10.3126/jhm.v6i1.5490Journal of Hydrology and Meteorology, Vol. 6, No. 1 66-75

A beginning course, carried out entirely off campus, which dealt with physical properties of the atmosphere and the ocean is described. Experiments and measurements included determination of the radius of the Earth, beach profiles, surface currents, sediment transport, and wave properties. The emphasis of the course was not on the results of the measurements; rather it was on a general approach, a method of observing, questioning, and seeking answers.

The Estuarine Sedimentation Research Group of King's College and Sir John Cass College has been studying the estuaries of the Thames, Medway and Taw-Torridge. Its members, who report some of their results here, have found that the sedimentary processes in the estuaries are varied and complex.

Various approximations to Basset's equation for the motion of a particle in a viscous fluid have been applied to the complex phenomenon of dispersion in a turbulent fluid. The deviations of the particle motion from the fluid motion, as predicted by the various approximations, is explored, and the frequencies for which this deviation is large are described. The approximations are found to be invalid for such cases as sediment transport and motion of gas bubbles in liquids. For small, 7 micron, liquid or solid particles in air, however, all approximations are shown to be valid for turbulent frequencies below 812 cps.

Observations of channel erosion, flow, and sediment transport for the Rio Puerco, in New Mexico, indicate that the characteristics of the channel and of the channel material change rapidly because of deposition and erosion, and that the ephemeral flows carry extremely high concentrations of suspended sediment that influence flow and transport characteristics.

(1957). Contribution to the study of sediment transport on a horizontal bed due to wave action. La Houille Blanche: Vol. 1957, No. sup2, pp. 693-710.

In this paper, the similarity, various similarity ratios and design methods of distorted rivermodels with movable bed in consideration ofnew developments in many researches for flowing water and sediment transport in open channels are investigated. The results obtained would contribute much to the designs and experiments of distorted or un-distorted river models with movable bed.

Extensive chert gravels underlying the Smithland and higher erosion surfaces of the uppermost portion of the Mississippi embayment are considered remnants of three coalescing alluvial fans related to the ancestral Mississippi, Cumberland-Ohio, and Tennessee rivers. The shape and topographic form of the largest of these remnants, the Smithland surface of western Kentucky, best illustrates an alluvial-fan origin. The ancestral Tennessee and Mississippi alluvial fans have contrasts in direction of sediment transport, heavy-mineral suites, metamorphic quartz, and sand roundness. Chert pebble roundness is similar, however, and experimental abrasion data indicate that the maximum roundness of 19-23-mm. chert pebbles can be obtained in approximately 70 miles. Available evidence suggests that a large but indeterminate portion of the primary and secondary modes was derived less than 100 miles from the Mississippi embayment's periphery.

1. Reef organisms may play a major role in the transport and distribution of sediment on the sea floor adjacent to coral reefs. 2. Some fish such asMalacanthus plumieri (Bloch) selectively transport and collect certain types of sediment (such as larger coral and shell fragments). 3. The random movement of crawling or burrowing organisms may cause a large amount of sediment to be shifted laterally on the sea floor. On slopes, a net downhill displacement may result. 4. The surface configuration and internal structure of the sediment is rapidly changed by faunal mixing. Ripple marks formed by waves or currents are obliterated by the activity of organisms in only a few weeks in the environment studied. Internal structure (bedding) near the sediment-water interface is similarly destroyed in a short period of time. 5. Larger clasts (including empty shells) on the sea floor tend to be buried by faunal undermining. The rate of burial depends primarily on the grain size of the substrate. 6. The random movement of fauna on the sea floor may produce a predominantly concave-up orientation of pelecypod shells and shell fragments on the sea floor — the opposite of that produced by the activity of waves or currents.

The formation of ripples and dunes (lower range bed waves) is assumed to be related to the transport of sediment as bed load. From the present theory it is concluded that the formation of the upper range bed configurations (standing waves, antidunes) may be explained on the assumption that the predominant part of the sediment transport is in suspension. The paper presents a mathematical model of the formation of double-periodic antidunes, first-order potential flow theory being applied. It differs from previous models in taking account of the non-uniform distribution of the suspended load. The theory predicts regions of stability and instability. Results are compared with measurements made by different observers.

In a former paper the writer (TAKAYAMA, S. 1956) mainly treated the problem of bed load transport. The present article describes the results of measurement on the transportation of suspended load of sediment by the three rivulets. In Fig. 1 are presented writer's results of measurement of the suspended load on these rivers (Hayakawa, Fukogawa and Okawa). Both the appreciable scatter of the points and the limited coverage of discharge range are evident. However, the trends of the regression lines indicate that suspended load discharge increases continuously with increasing discharge. The equations for the lines for average conditions of Hayakawa, Fukogawa and Okawa are respectively: Ha akawa; QS=114.1 Q2•48 Fukogawa; QS=89.9 Q1•72 Okawa; QS=51.3 Q2•06in which Qs is the suspended load in tons per second, Q is the water discharge in cubic meter per second. The coefficient and the exponent in the equations are different from each other due to the condition of the surface of the drainage area at the time, the rate of availability of sediments and other factors. Usually the suspended load seems to vary approximately as the square roots of the water discharge and this means that the values of increment of suspended load with water discharge is generally larger than that of bed load. Two fairly distinct trends could be discerned (one for the flood occured August through September when high flows take place; the other for the flood of October when flood stage is not so high) from Fig. 1. This difference is thought to be due to the changing volume of fine-grained river bed material which can be easily transported. That is, the river bed is filled with fine-grained particles subsequent to several weeks of low stages; then the flood peak in August and September completely removes these particles. Total sediment discharge is computed as the sum of suspended discharge and bed load discharge. It is the total quantity of sediment as measured by dry weight, that is discharged during a given time. For example, in Fig. 2, the area under the curves (QS-T and QB-T) represent the sum of suspended load [QS] and that of bed load [QB] respectively during a flood (Tab. 1) . Hydrograh for this flood is shown in Fig. 3. The percentage ratio of [QB] to [QS] (hereafter designated as QB/QS) varies with the scale of flooding as shown in Fig. 3. There is a tendency that the bed load movement dwindles to small portions as the maximum water discharge increases. The gross amounts of sediment transported as bed load, suspended load and total sediment load during the observed period are calculated by continuous summation of [QB], [QS] and [QT] of each flood and Σ QB, Σ QS and Σ QT obtained as tabulated in Tab. 2. In order to provide data on comparative basis, these values are reduced to the values per square kilometer of drainage area. There are great spatial variations among them and these differences may be reflected not only in the character of sediment but also in the landforms themselves in each drainage area. The geomorphic features which appear to be significant to sediment delivery are mean altitude of a drainage basin, maximum relief in a drainage area, mean watershed slope, mean channel slope and mean relief ratio (Fig. 4 & 5, Tab. 3).

Available evidence strongly suggests that many ancient clastic rocks show markedly preferred directions of sediment transport. Statistical analysis is useful in studying such transport systems because it can segregate local, intermediate, and regional variability. On the local and intermediate sampling levels current variability depends on the local hydrodynamic regimen. Tectonics, however, is the fundamental control for both wide lateral and thick vertical persistence of flow pattern. In all fluvial and argillaceous marine sands, regional field mapping of appropriate sedimentary structures indicates the regional slope without ambiguity. In the clean marine-shelf sands available evidence for a regional-slope interpretation is scanty, and, although such a hypothesis seems highly plausible for many ancient sediments, further studies of directional structures in marine-shelf deposits are required. Because regional petrology distinguishes regional mineral associations, it helps confirm sedimentary transport f...

Analyses of paleocurrents are based on averaging or summing techniques of directional data and are aimed at finding the primary directions of sediment transport, the directions of source areas, or the outlines of basins of deposition. It is suggested that the resolution achievable by these techniques can be increased by using the optimum or ideal summation limits. The outlines of basins or dispersal patterns can be located from differences between vector averages or sums of adjacent sections or submatrices of the total array of data. These differences are at their maximum when the span of the submatrix over which summing is carried out happens to coincide with the extent of the paleoccurrent basin. The technique proposed here is applied to fluvial patterns on topographic maps, where drainage basins and subbasins are reconstructed from stream flow directions.

Sediment transport and accumulation were studied over several years to define the sedimentary environment in a fan-terminated, active valley glacier and adjacent fjord at Queen Inlet, Glacier Bay National Monument, Alaska. Recently exposed ice-contact sediment at the glacier snout is entrained during summer and early fall by meltwater streams crossing a subaerial-intertidal outwash fan. Suspended sediment in the meltwater (sediment loads exceed 1 g/liter at the inlet head) subsequently yields a cold, surface sediment plume overlying warmer saline water in the fjord basin. Mixing of these layers produces flocculation and settling occurs in discrete layers; each layer is considered to represent one tidal cycle. No gravel is present in fjord floor sediment, although both colluvium and outwash fan sediments contain gravel. This gravel distribution eliminates sliding, slumping of the outwash fan, and ice rafting as major contributors to fjord basin sediment in Queen Inlet. Piston cores of muddy fjord basin sed...

Field studies and laboratory experiments in large recirculating flume have established that resistance to flow and sediment transport in alluvial channels are related to form of bed roughness; forms of roughness can be divided into lower and upper regimes of flow on basis of their shape, resistance to flow, and sediment transport; possible relationship that may prove useful in predicting configuration of bed is introduced.

SYNOPSIS The paper presents briefly the broad implications of computer technology on research in sediment transport, and provides a particular example of the application of the computer to the lengthy computation of data obtained from the particle size analysis of suspended sediment using a Coulter Counter.

Dip direction of torrential cross-bedding is a vectorial property providing a rapid measure of the local direction of sediment transport. Over 500 measurements in the basal Pennsylvanian Caseyville and Mansfield sandstones of southern Illinois and Indiana were taken, to explore its possibilities and limitations as a measure of direction of regional sediment transport. The analysis of variance helped interpret the pattern of variability, indicate the reliability of averages, and improve the efficiency of sampling effort. The host topography of the Mississippian-Pennsylvanian unconformity exercised a strong control on the basal cross-bedding direction. Averages of many measurements along 260 miles of outcrop, however, accurately indicate a southwesterly direction of sediment transport for the Caseyville and a southerly direction for the Mansfield. The importance of a northerly source is suggested but would have to be evaluated by petrologic study.

The results of experimental and theoretical investigations are presented for certain sediment characteristics found pertinent to the control of localized scour in alluvial channels. The relationship between fall velocity of the sediment particle, velocity at the beginning of sediment motion, tractive force, and bed shear velocity is developed in terms of the nominal particle diameter. An example on the practical use of the data is provided. All results are presented in the form of graphs.

Contrasts in the occurrence of cyclic cuspate spits are found (1) between a smooth sandy oceanic barrier shoreline and spit-decorated shorelines of the associated narrow barrier lagoon, and (2) in spit development varying from none on a straight sandy shoreline to progressively prominent development with increasing convexity along an adjoining sandy headland. Critical factors in this selectivity seem to be wave fetch and shoreline curvature; both factors present contrasts in the efficiency of longshore sediment drift of coarse particles. Examples of wave fetch include southeastern Alabama and the coasts of St. Lawrence Island, Alaska; examples of shoreline curvature are believed to include both the large salient of the Cape Hatteras-Cape Fear-North Island sandy cuspate foreland and the small sandy foreland of Cape Sable, southwestern peninsular Florida. These contrasts seem to have escaped previous notice. The conditions are not found on all barrier-lagoon or sandy headland shorelines.

1952 and 1955 to determine deposition of sediment; particle size distribution analyses of 30 sediment samples were utilized to determine tons of sediment deposited; curves of water discharge versus sediment discharge were computed utilizing Einstein procedure, Schoklitsch formula and DuBoys formula.

Landslide movement of sediments is a significant mode of sediment transport in certain subaqueous environments. A detailed study of Lake Tahoe, California-Nevada has shown that a series of massive, basin-wide landslides deposited a large portion of the thick bottom sediments. The latest of these landslides was comparable in volume with the largest landslides ever recorded. Several large mounds occur on the floor of Lake Tahoe. It is postulated that these mounds were formed by landslides. At the base-of-slope environment, many mounds are well layered and rotated backward suggesting deposition as coherent slump blocks. Mounds further from the base of slope are circular or elliptical in area, have a pebbly mudstone sedimentary texture, display a disordered internal structure on seismic reflection profiles, and are located on an extensive layer of similarly disordered sediments. We suggest that such mounds formed along dewatering centers during the rapid deposition of an incoherent landslide mass. A subaqueou...

In the previous paper, the authors theoretically analysed (dynamic) equilibrium bed slope in rivers with sediment transport. In this paper, the authors theoretically analysed static equilibrium bed slope in rivers, as well as dynamic equilibrium bed slope in rivers with sediment transport.Combining the equations of motion and continuity for non-uniform steady flow with the condition of critical tractive force, the outhors introduced the fundamental equation of static equilibrium bed slope in rivers, by solving this equation of motion for non-uniform steady flow. From this fundamental equation, the authors introduced the equations of static equilibrium bed slope in rivers with gradually varied width and same width.

A ring count of cottonwood trees along the Little Missouri River in western North Dakota has permitted contouring of the age of floodplain forests. The germination and growth of the cottonwood is closely related to the discharge of the river, movement of the channel, and development of the floodplain. The trees, in bands, show an orderly increase in age upvalley and away from the channel. Each band is the result of the rise of a thicket on a riverside sandbar and, thus, a record of recent migrations of the channel. A model of channel migration and sediment transport has been constructed. Evidence indicates that the channel has been within a few feet of its present elevation for the past 150 years.

Cross-bedding in the pre-Cambrian Baraboo quartzite of Wisconsin indicates that the average direction of sediment transport was S. 17° E. for the 4,000-5,000 feet of strata. This is roughly corroborated by ripplemark measurements. Changes of direction of transport in time are only suggestive, because of the difficulty in dividing the strata at a common horizon; however, some fluctuation is shown, although currents were still in a southerly direction.

In this paper, the authors theoretically analyzed the equilibrium bed slope in rivers with sediment transport with gradually varied width and same width of rectangular cross sections, in consideration of the new developments in the many researches of flowing water and sediment transport in open channels. Combining the equations of motion and continuity for non-uniform steady flow with the equations of motion (formula for sediment transportation) and continuity for sediment transport and the equations of the resistance law for flowing water with sediment transport, the authors introduced the fundamental equation of the equilibrium bed slope in rivers with sediment transport by solving the equation of motion for non-uniform steady flow. Furthermore, the authors introduced the formulas of the equilibrium bed slope in rivers with sediment transport with gradually varied width and same width of rectangular cross sections from above fundamental equation.Last of all, a numerical example was added to demonstrate the method of application to a river with sediment transport.

SYNOPSIS The simulation of sediment transport processes in a watershed by means of a mathematical model on a digital computer, as developed by Negev (1) at Stanford University is considered, and the translation of this sediment model is presented in a commonly used, European computer programme language.

SYNOPSIS The application of a suspended solids monitor to the continuous recording of suspended solids in river water, is discussed in relation to sediment transport and water quality studies. The detailed description of a commercially available instrument, together with a discussion of its results are included.

Synopsis A method of synthesis has been used to combine the variables characterising sediment transport in laboratory flumes into nondimensional functional equations. These equations are used to provide a basis for logical data correlations. By selecting appropriate nondimensional groups the effect of variation of individual variables such as flume width, sediment grain size, etc., can be determined. It has been found that work of this nature is hampered by the small amount of data available from rational experimentation. Much of the published data is unsuitable for direct use in correlations but may be of use in the future once the trend of results has been predicted by more limited but more basic data. When sufficient data for the transport of light weight materials is available correlations of the type presented may provide a secure basis for the choice of bed material for hydraulic models.

SynopsisSandy beaches are defensive zones created by nature, protecting the land against aggressive oceanic forces. They are very flexible and their configulations are varying daily, seasonally and annually, depending on many factors, such as wave characteristics, beach materials, shore structures and the others. The investigation of beach erosion is one of the most important and difficult subjects in coastal engineering.In this paper, a method for investigating the mechanism of beach erosion is presented, concerning the investigation practice of beach erosion along the north coast of the Akashi Strait, and the author's opinion of the following three subjects to be investigated is described:(a) Distribution of sand drift along the coast,(b) Distribution of sand drift along the beach profile, and(c) General characteristics of sand drift, suCh-as the type of sediment transport, the direction of drift and the others.