KAPLAN. WELKER, and KRAUS: EFFECTS OF DREDGING 



for the second survey (triangles) taken just 

 before the dredging in June 1967, and the post- 

 dredging survey (circles) in July 1968, 1 yr after 

 dredging. 



Table 4 reveals that 1 yr after dredging, sedi- 

 ments in those stations in the path of the dredge 

 (3, 10b, 11, and 11a) contained less sand after 

 dredging in the previously sandy, high current 

 velocity stations (3, 10b) and more sand in the 

 previously silty, low current velocity stations 

 (11, 11a). 



Station 10a, in channel A, experienced a reduc- 

 tion in its sand proportion and an increase in silt. 

 This conforms to the hypothesis that the lowered 

 current velocity in channel A, resulting from a 

 shift in the main volume of water transport to 

 channel B, would favor the settling of lighter 

 particles in the post-dredging period. Similarly, 

 station 5 in channel C increased in its silt and 

 clay components. 



Stations 16 and 17 were located in the west- 

 central portion of the bay, south of the channel. 

 Both stations maintained a constant proportion of 

 sand. Station 17 exhibited a marked increase in 

 silt and a decrease in the clay facies. 



Stations 14 and 24 exhibited an increase in 

 sand and a decrease in silt and clay. Since these 

 stations were near the western shore in an area 

 of negligible current flow, it is difficult to envision 

 pronounced sediment transport brought about by 

 normal tidal flow, even with the slightly enhanced 

 exchange rate brought about by the deepening of 

 channel B. It is possible that spring tides and 

 strong easterly winds could have acted syner- 

 gistically with the deepened channel to bring 

 about this effect. 



GOOSE CRIEK NY. 



Figure 7. — Sediment facies and station locations, Goose Creek. 

 Triangles represent pre-dredging stations, circles represent 

 post-dredging stations. 



The foregoing data must be viewed in con- 

 junction with data on current velocities, wind- 

 driven currents, etc., as further presumptive 

 evidence of what appear to be permanent changes 

 in the sediment transport patterns of Goose 

 Creek brought about by current velocity modifica- 

 tions in the tidal channels. 



The Effects of Wind-Driven Currents 

 on Sediment Deposition 



The importance of wind-driven water currents 

 on the deposition of sediment in shallow-water 

 estuarine situations has been emphasized by 



Table 4.— Comparison of pre- and post-dredging sediment composition at selected stations. 



Goose Creek. 



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