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Anthropogenic changes in the suspended..

Fig. 7. 5-year running means of annual suspended load transportation in successive gauging

stations on the Vistula in years 1946-1990. For numbering of gauging stations see Fig. 1

EXPLANATION OF THE ANTHROPOGENIC INFLUENCES WHICH HAVE CAUSED CHANGES IN THE TRANSPORTATION AND SEDIMENTATION RATES OF THE VISTULA

1. Channel downcutting. Downstream effects. Long deepened stretches of the Upper and Lower Yistula channel, together with a short stretch of the channel near Warsaw, supply large amounts of coarse materiał which is only partially deposited on the floodplain. As a result of the increased river competency due to the channel remodelling initiated by channel regulation, the rest of that materiał is transported longer distances. The materiał is aggraded downstream, where a wide braided channel is still being formed. Thus, the present-day Vistula is typified by an altemation of relatively deep and relatively shallow stretches of the channel (Fig. 8). By recording the rates of channel downcutting, channel narrowing, levee growth, and channel aggradation, it is possible to estimate, at least approximately, the amounts of sediment transportation and deposition which have occurred