Author(s): Ricardo Garcia; Jose Luis Garcia; Jose C. Robredo

Linked Author(s):

Keywords: River permeability; Fish scale; Gauging station; Fish migration; Ichthyofauna restoration

Abstract: A new type of successive trough scale adapted to gauging stations with a minimum flow channel (mfc) is presented in order to permeabilise the barrier caused by the water jump from this channel to the river. The mfc of the station is built at a certain height with respect to the levels of the river so that it does not affect the flow through this channel and measurement is possible, which creates a barrier that prevents fish from rising. The first pool of this scale requires a detailed design and calculation, special and different from the usual trough scales, so that the water level in it does not flood the flow with an excessive height. For this purpose, there are numerous weirs in this basin, which make it possible to adjust the water level for the different flow rates and thus the difference in height with respect to the downstream flow sheet in the flume. The quantification of the measurement error as a function of the degree of submergence is obtained from the abacus of the research carried out by the U.S. Army Engineers Waterways Experiment Station (1952). The calculation is made on the basis of the design of the first pond with the weirs considered appropriate, checking that it is valid for the values of the flows considered; for each value, the possible existence of error must be checked in order to modify the weirs or the difference in level. Once the first pond is established, the design and calculation of the rest of the ponds is made easier with the conditions that facilitate that the difference in level between the ponds allows the fish to ascend without difficulty and that the hydraulic power dissipated is below the admissible threshold.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221405

Year: 2022