BOAT-GENERATED WAVES AND EROSION ON THE SHORE OF THE XINGÓ POWER PLANT RESERVOIR

In fluvial environments, water speed depends on important factors such as longitudinal slope, water volume, channel shape (cross section), bed roughness, and water viscosity, all of which affect speed in different sections of the channel in which it flows. Waves generated by boats present a complex distribution, with the formation of primary and secondary wave systems. The objective of this work was to describe the erosive effects of waves from tourism boats on the lake banks at the Xingó hydroelectric power plant in northeastern Brazil. Measurements taken on site as well as data from environmental monitoring systems were used to determine the characteristics of the lake, while wave heights were calculated according to the effects of transverse and divergent waves. The wave propagation behavior observed in this present study alone cannot be responsible for erosion on the banks and slopes of the lake, since this is also associated with the presence of wind fetch, human activities, deposit of transported sediments resulting from operations at the power plant, as well as other factors. The findings confirmed observations that the tour boats do not directly cause erosion, since they are limited to subcritical speeds, but wind was seen to be directly related to this phenomenon