Measurements of Tidal Current Velocities in the Folda Fjord, Norway, With the Use of a Vessel Mounted ADCP

Abstract

Measurements of tidal current water velocities is an important first step in evaluating the potential for a tidal site to be used as a renewable energy resource. For this reason, on site measurements are performed at the inlet of a fjord situated at the coast of Norway. The site has an average width of 580 m and a depth of 10–15 m which is narrow and shallow enough to give rise to water velocities that can be of use for energy conversion. With the use of an Acoustic Doppler Current Profiler (ADCP) cross-section measurements are conducted along four transects. The measurements covered flood and ebb currents around one tide and the data give a first approximation of the magnitude and distribution of the flow field. Depth averaged mean current velocities are calculated along the transects for horizontal bins with sizes in the order of 50 × 50 m. Maximum mean velocity for the flood currents were 1.31 m/s and 1.46 m/s for the ebb currents. The measurements show that even a small amount of data can give an indication of the potential and characteristics of the site.

Changes in surface water and sediment quality at a complex tidal-influenced river: a case study of Ganh Hao river, Mekong delta, Vietnam

“…Furthermore, velocities were highest at mid tide (12 p.m.) when compared to velocity at high tide (9 a.m.) and low tide (3 p.m.) (Figure 5.5). The current velocities at low and high tide were lower than flow velocities throughout the intertidal period, and were close to zero during the unchanging tide [318]. Changes in hydrodynamic characteristics, on the other hand, resulted in spatial geomorphological alterations of the river reach as a result of deposition or erosion, which arose closer to the outer bank than the inner bank (Figure 5.4).…”